CN1720396A

CN1720396A - Combination of a chamber and a piston, a pump, a shock absorber, a transducer, a motor and a power unit incorporating the combination

Info

Publication number: CN1720396A
Application number: CNA200380104797XA
Authority: CN
Inventors: N·范德布鲁姆
Original assignee: NVB Composites International AS
Current assignee: NVB Composites International AS
Priority date: 2002-10-02
Filing date: 2003-10-02
Publication date: 2006-01-11

Abstract

A piston-chamber combination comprising an elongate chamber which is bounded by an inner chamber wall, and comprising a piston in said chamber to be sealingly movable relative to said chamber wall at least between a first longitudinal position and a second longitudinal position of the chamber, said chamber having cross-sections of different cross-sectional areas and different circumferential lengths at the first and second longitudinal positions, and at least substantially continuously different cross-sectional areas and circumferential lengths at intermediate longitudinal positions between the first and second longitudinal positions, the cross-sectional area and circumferential length at said second longitudinal position being smaller than the cross-sectional area and circumferential length at said first longitudinal position, said piston comprising a container which is elastically deformable thereby providing for different cross-sectional areas and circumferential lengths of the piston adapting the same to said different cross-sectional areas and different circumferential lengths of the chamber during the relative movements of the piston between the first and second longitudinal positions through said intermediate longitudinal positions of the chamber. The piston is produced to have a production-size of the container in the stress-free and undeformed state thereof in which the circumferential length of the piston is approximately equivalent to the circumferential length of said chamber at said second longitudinal position, the container being expandable from its production size in a direction transversally with respect to the longitudinal direction of the chamber thereby providing for an expansion of the piston from the production size thereof during the relative movements of the piston from said second longitudinal position to said first longitudinal position.

Description

Combination of a chamber and a piston, and pump, damper, transducer, motor and power unit using the combination

Technical Field

A piston-chamber combination comprising an elongate chamber defined by an inner chamber wall and comprising a piston, the piston being arranged in said chamber to be sealingly movable relative to said chamber at least between a first and a second longitudinal position of said chamber, the cross-section of the cavity has different cross-sectional areas and circumferential lengths at first and second longitudinal positions of the cavity, and at least substantially continuously different cross-sectional areas and circumferential lengths at intermediate longitudinal positions between the first and second longitudinal positions of the cavity, and the cross-sectional area at the first longitudinal position is greater than the cross-sectional area at the second longitudinal position, the piston comprises a cavity with an elastic deformable cavity wall for being hermetically connected with the inner wall of the cavity, the chamber is elastically deformed and the piston is expanded to provide different cross-sectional areas and circumferential lengths. The cavity is elastically deformable so as to provide different cross-sectional areas and different circumferential lengths of the piston to accommodate different cross-sectional areas and different circumferential lengths of the cavity when the piston is moved in relation to the first and second longitudinal positions extending through the longitudinal position inside the cavity.

The inflation valves are the Dunlop-Woods valve, the Sclaverand valve and the Schrader valve. These valves are used to inflate closed cavities, such as the tires of vehicles. The latter two types of valves mentioned are provided with a spring force operated spool pin and can be opened by depressing the pin to inflate or deflate the chamber. Depressing the poppet pin may be accomplished by manual actuation, by the pressure of a fluid, or by a valve actuator. The first two types of valves can be opened by the pressure of the fluid only, while the last type of valve is preferably opened by a valve actuator because otherwise a significant pressure would be required to depress the valve pin.

Background

The present invention is directed to solving the following problems: the friction forces obtained are low enough to at least avoid jamming, in particular for pistons with elastically deformable cavity walls and walls that extend the cavity in a stroke, the cavities having dimensions of different cross-sectional areas in the longitudinal direction, in particular when the piston moves sealingly in the above-mentioned cavity, they have different circumferential lengths.

A problem with the embodiment of WO00/70227 shown in figures 6, 8-12 (included herein) may be: the piston may jam in a smaller cross section of the chamber having a cross section of a different circumferential dimension. Seizure may be due to high friction of the piston material. These forces may be mainly due to (a part of) the piston being pressurized when it moves from a first longitudinal position in the chamber with a larger cross-sectional area to a second longitudinal position with a smaller cross-sectional area. Figures 1-3, included herein, show examples of high friction forces for an unmoved piston including a pocket with or without internal pressure in the non-moving chamber. This causes high contact pressure between the piston and the chamber wall, and seizure may occur.

Another problem may be: the embodiments of the piston of WO00/70227 comprising a chamber may leak their fluid and may therefore alter their sealing suitability. As in the solution of the aforementioned problem with pistons comprising a chamber with elastically deformable walls, where the sealing force is generated by internal pressure, leakage may still be a significant problem.

Object of the Invention

The object of the present invention is to provide a combination of a piston and a chamber, the movable part of which can slide sealingly when the chambers have different cross-sectional areas and at least when the circumferential lengths of these cross-sections are different.

In a first aspect, the present invention relates to a combination of a piston and a chamber, wherein:

the receptacle is made elastically expandable and dimensioned with a circumferential length in a stress-free and deformation-free state, approximately equal to the circumferential length of the inner wall of the cavity of the receptacle at said second longitudinal position.

In the context of this document, a cross-section is preferably taken perpendicular (transverse) to the longitudinal axis.

Preferably, the second cross-sectional area is 98-5%, such as 95-70%, of the first cross-sectional area. In one instance, the second cross-sectional area is approximately 50% of the first cross-sectional area.

Many different techniques may be used to achieve such a combination. These techniques are further described in association with subsequent aspects of the disclosure.

One such technique is: wherein the piston includes a cavity and the cavity contains a deformable material.

In such a case, the deformable material may be a fluid or a mixture of fluids such as water, steam, and/or gas, or a foam material. The material or a part thereof may be compressible, such as a gas or a mixture of water and gas, or it may be at least substantially incompressible. The deformable material may also be a device such as a spring that provides a resilient force.

Thus, the cavity may adjustably provide a seal to cavity walls having different cross-sectional areas and different circumferential lengths.

This can be achieved by choosing the e.g. manufactured dimensions (stress free, undeformed) of the piston to be approximately equal to the circumferential length of the smallest cross-sectional area portion of the cavity cross-section, and expanding it when moving to a longitudinal position with a larger circumferential length and connecting it when moving in the opposite direction.

And this can be achieved by providing means to maintain some sealing force of the piston against the chamber wall: by maintaining the internal pressure of the piston at (a) a predetermined level, it can be maintained constant during the stroke. The pressure level of a certain size depends on the circumferential length of the different cross-sections and it is possible to obtain a suitable sealing with a minimum circumferential length in cross-section. If the difference is large and the appropriate pressure level is too high to obtain a proper seal over the minimum circumferential length, it may be arranged to vary the pressure during the stroke. This requires a pressure arrangement of the piston. As commercially used materials are often not tight, in particular, when too high a pressure may be used, it must be able to withstand maintaining this pressure, for example using a valve for inflation purposes. When using a spring force operated device to obtain the pressure, a valve may not be necessary.

As the cross-sectional area changes, the volume of the pocket also changes. Thus, in a cross-section through the longitudinal direction, the cavity may have a first shape at a first longitudinal position and a second shape at a second longitudinal position, and the first shape may be different from the second shape. In one case, at least a portion of the deformable material is compressible and the first shape has a larger area than the second shape. In this case, the total volume of the chamber varies and the fluid should therefore be compressible. Alternatively or additionally, the piston may comprise an enclosed space in communication with the deformable volume, the enclosed space having a variable volume. In this way, the enclosed space can draw in or release fluid when the volume of the deformable volume changes. The change in volume of the chamber is automatically adjustable. This also keeps the pressure in the chamber constant during the stroke.

Also, the enclosed space may include a spring biased piston. The spring may limit the pressure in the piston. The volume of the enclosed space may vary. In this way, the total or maximum/minimum pressure of the chamber can be varied.

When the enclosed space is divided up into a first and a second enclosed space, the spaces further comprise means for defining the volume of the first enclosed space such that the pressure of the fluid in the first enclosed space is related to the pressure in the second enclosed space. The latter space mentioned may be inflatable, for example by means of a valve, preferably an inflation valve such as a Schrader valve. The equalization is achieved by the expansion of the second enclosed space by the confining means due to a possible pressure drop due to leakage, e.g. through the cavity wall volume. The restricting means may be a pair of valves, each in a closed space.

The defining means may be adapted to define the pressure in the first closed space to be at least substantially constant during the stroke. However, the defining means may define any pressure level: for example, where the cavity expands to a large cross-sectional area at the first longitudinal position such that the contact area and/or contact pressure may become too small at the present values of pressure, the pressure may need to be increased to maintain a suitable seal. The restricting means may be a pair of pistons, one for each enclosed space. The second enclosed space may be inflated to a pressure level such that the rising pressure is communicated to the first enclosed space, although the volume of the second enclosed space may also be larger. This can be achieved by, for example, a combination of a piston contained in the second enclosed space and a cavity with different cross-sectional areas in the piston rod. The pressure drop can also be designed.

Pressure manipulation of the piston may also be achieved by correlating the fluid pressure in the enclosed space with the fluid pressure in the cavity. By providing means for defining a volume of the enclosed space in communication with the cavity. In this way, the pressure of the deformable volume is variable to obtain a suitable seal. For example, it is a simple way to adapt the defining means to define a pressure rise in the enclosed space when the cavity is moved from the second longitudinal position to the first longitudinal position. In this way a simple piston between the two pressures can be provided (so as to not leak any fluid in the deformable volume).

In fact, the use of this piston may define any relationship between pressures, as the cavity in which the piston translates may taper in the same manner as the main cavity of the assembly.

The means directly transferable from the piston rod to the reservoir may also vary the volume and/or pressure of the reservoir. It is possible that the piston is not in communication (closed system), or is in communication with, the inflation valve. When the piston does not have an inflation valve, the material of the chamber wall may be fluid impermeable. After filling the piston with fluid and setting it in said second longitudinal position in the chamber, a step of the installation process causes the volume of the receptacle to be permanently closed. The available speed of the piston towards and away from said first closing chamber will depend on the possibility of large fluid flows without much friction. There will be a proper flow of the chamber wall when the piston has an inflation valve.

The chamber may be inflated by a pressure source within the piston or by an external pressure source, such as a pressure source external to the assembly and/or the chamber itself. All solutions require a valve in communication with the piston. It may preferably be an inflation valve, most preferably a Schrader valve, or a valve having a spring operated valve core in general. This type of valve is provided with a spring-biased valve core pin and closes independently of the pressure in the piston and through which various fluids can flow. But it could be other types of valves such as a one-way Hades.

The chamber may be inflated through a closed space in which a spring biased regulator piston operates as a one-way valve. Fluid can flow from a pressure source, such as an external pressure source or, for example, an external pressure vessel, through longitudinal ducts in the bearings of the piston rods of the spring-biased pistons.

Inflation may also be accomplished with the chamber acting as a pressure source when the enclosure is divided into a first and second enclosure, as the second enclosure may prevent inflation therethrough to the first enclosure. The chamber may be provided with a suction valve at its bottom. For the inflation of the chamber, an inflation valve, such as a Schrader valve, may be used with an actuator. This may be an actuating pin according to WO 96/10903 or WO 97/43570, or a valve actuator according to WO99/26002 US5,094,263. The core pin of the valve moves toward the cavity when closed. The actuating pin in the above-referenced international publication has the advantage that: the force of opening the elastic force-operated valve element is small, so that the expansion of the manually-operated pump is easy to perform. The actuator in said us patent would require the force of a normal compressor.

The piston may be automatically inflated when the working pressure in the cavity is higher than the pressure in the piston.

When the working pressure in the chamber is lower than the pressure in the piston, a higher pressure needs to be obtained by, for example, temporarily closing a drain valve at the bottom of the chamber. If the valve is a Schrader valve which can be opened by means of the valve actuator according to WO99/26002, this can be achieved by providing a bypass in the form of a passage connecting the cavity and the space between the valve actuator and the core pin. The bypass is open (Schrader valve can remain closed) and closed (Schrader valve can be open) and can be accomplished by, for example, a movable piston. The movement of the piston may be set manually, for example by means of a pedal which is rotated by an operator about an axis from an unactuated position to an actuated position or vice versa. This may also be achieved by other means such as an actuator activated by a pressure measurement in the chamber and/or the reservoir.

The achievement of a predetermined pressure in the chamber may be effected manually, the operator being informed from a pressure gauge measuring the pressure in the chamber. It may also be achieved automatically, for example by a release valve in the chamber, to release fluid when the fluid pressure exceeds a maximum pressure setting. It may also be accomplished by a spring force operated cap which closes a passage above the valve actuator when the pressure exceeds a certain predetermined pressure value. Another solution is a solution similar to the solution of a closable bypass of the chamber drain valve, in which chamber a pressure measurement may be required, which may operate an actuator to open and close the bypass of the valve actuator according to WO99/26002 of a Schrader valve of the chamber at a predetermined pressure value.

The above described solution is applicable to any piston comprising a chamber, including those in WO00/65235 and WO 00/70277.

The above technique is directed to the inclusion of a pocket within the piston, the pocket comprising a resiliently deformable pocket wall.

The cavity wall may be expanded and contracted by selecting a reinforcement portion that allows the cavity wall to expand and contract in a three-dimensional manner. The cavity wall may be created by varying the size of one cross-sectional circumferential length. Thus, no excess material remains between the cavity wall and the cavity wall. The choice of a suitable reinforcement can withstand the effect of the pressure in the upper chamber of the piston in order to limit the contact length (longitudinal extension). The reinforcement of the chamber wall may or may not be placed in the chamber wall.

The stiffening of the wall of the chamber may be made of a textile material. It may be one layer, but preferably at least two layers which may cross each other, so that the reinforcement can be installed more easily. These layers may, for example, be woven. The braided wires may be made of an elastic material, since they are to be placed close to each other in different layers. Such as between two layers of elastomeric material, such as rubber, the layers may be vulcanized. When the cavity is manufactured to have a size, not only the elastic material of the wall, but also the continuous reinforced part has no stress and no deformation. The expansion of the walls of the reinforced receptacle means that the distance between the points of intersection (i.e. the size of the slit) can be made longer by lengthening of the thread, while the contraction can be made shorter by shortening of the thread. The sealing of the chamber wall to the chamber wall may be achieved by appropriate pressurisation of the chamber. Here, the suture size can be made longer by slightly lengthening the thread. The connection of the chamber walls may inhibit the internal pressure from expanding the chamber in such a way that the length of the connection will become extra long and that the pressure can be eliminated by compression.

The knitted reinforcement may, for example, be made of elastic threads and/or elastic bending threads. Expansion of the wall of the vessel can be achieved by stretching the curved portion of the braid. And the elongated curved portion returns to an undeformed state when the chamber wall contracts.

The textile reinforcements can be produced on a production line, where either the knitted or woven reinforcements are placed in the shape of a cylinder between two layers of elastic material. In the smallest cylinder a support is placed on which a cover is mounted in the order of up-down-up-down, said cover being movable onto said support. A curing oven is installed at the end of the production line. The furnace has a cavity of a size and shape in an unstressed and undeformed state. The furnace cylinder portion may be cut along its length, with two covers formed at the ends of the cylinder and held there. The furnace is shut down and steam at above 100 c and high pressure is injected. After about 1-2 minutes, the oven was opened and the chamber wall with the two lids ready for production was vulcanized in the wall. To use the minute lead time for vulcanization, there may be multiple ovens, such as spinning or converting, and ending at the end of the production line. There may be multiple furnaces on a production line using the transport lead time as the cure time.

The production of fibre-reinforced walls of the cavity may also be done similarly. The reinforcing fibres may be produced by including an assembly socket, for example by potting, or by cutting a line which is then placed at both ends of the assembly socket. Both options are easily produced continuously. For the remainder, the production process is similar to that described above in relation to the production of textile reinforcements.

The piston comprising a resiliently deformable chamber further comprises reinforcements which are not located in the wall connecting to the chamber wall, such as a number of resilient arms which may or may not be expandable. When expandable, the stiffening portion may act to limit deformation of the cavity wall due to cavity pressure.

Another option is to have a reinforcement outside the chamber wall.

Another aspect of the invention relates to a combination of a piston and a chamber, wherein:

by cavity is meant an elongated cavity having a longitudinal axis,

the piston is movable within the chamber at least from the second longitudinal position to the first longitudinal position,

along at least part of the inner wall of the cavity between the first and second longitudinal positions, the cavity having an elastically deformable inner wall,

the chamber has a first cross-sectional area when the piston is disposed in the first longitudinal position, a second cross-sectional area when the piston is disposed in the second longitudinal position, the first cross-sectional area being greater than the second cross-sectional area, and the change in the chamber cross-section is at least substantially continuous between the first and second longitudinal positions as the piston moves between the first and second longitudinal positions.

Thus, for the alternative combination, the piston accommodates variations in the cross-section of the chamber, this aspect being related to the chamber having the resilience.

Naturally, the piston is made of an at least substantially incompressible material, or a combination of a compliant cavity and a compliant piston, such as a piston according to the above aspect.

Preferably, the piston has a shape in cross-section along the longitudinal axis, which shape is tapering in a direction to the second longitudinal position.

One desirable method of providing a compliant chamber is to have a chamber comprising:

an external support device on the inner wall and

-a fluid which is installed through a space defined by the outer support means and the inner wall.

In the above method, the selection of the fluid or combination of fluids may help to define the characteristics of the cavity, such as the seal between the wall and the piston and the required pressure.

In another aspect, the invention relates to a combination of a piston and a chamber, wherein:

by cavity is meant an elongated cavity having a longitudinal axis,

in a first longitudinal position, the cavity has a shape and an area of a first cross-section; in the second longitudinal position, the cavity has a shape and area of a second cross-section. The first cross-sectional shape being different from the second cross-sectional shape, the variation in the cavity cross-sectional shape being at least substantially continuous at the first and second longitudinal locations,

the piston adapts itself to the cavity cross section when moving from the cavity first longitudinal position to the cavity second longitudinal position.

This very interesting aspect is based on the fact that different shapes, e.g. a geometric figure, have a varying relation between their circumferential length and area. Furthermore, the change between the two shapes may be made in a continuous manner, so that the cavity may have one cross-sectional shape at one longitudinal position and another cross-sectional shape at a second longitudinal position while maintaining an optimal smooth change in the cavity surface.

In the present specification, the shape of the cross section refers to the overall shape regardless of the size thereof. The two circles are identical in shape even though their diameters are different from each other.

Preferably, the area of the first cross-section is at least 2%, such as at least 5%, in particular at least 10%, such as at least 20%, in particular at least 30%, such as at least 40%, in particular at least 50%, such as at least 60%, in particular at least 70%, such as at least 80%, such as at least 90%, such as at least 95% larger than the area of the second cross-section.

In a preferred embodiment, the first cross-section is at least substantially circular in shape, and the second cross-section is elongated, such as elliptical. The first dimension is at least 2 times, such as at least 3 times, preferably at least 4 times, a dimension at an angle to the first dimension.

In another preferred embodiment the first cross-section is at least substantially circular in shape, while the second cross-section is shaped with two or more substantially elongated portions, e.g. in the shape of an ear lobe.

There may be advantages in that the first circumferential extent of the cavity in the cross-section at the first longitudinal position is 80-120%, such as 85-115%, preferably 90-110%, such as 95-105%, in particular 98-102% of the second circumferential extent of the cavity in the cross-section at the second longitudinal position. Problems arise when the sealing material is intended to seal a wall of varying dimensions, due to the fact that it is both to provide an adequate seal and to vary its dimensions. If the situation is such that the circumferential length varies only to a small extent as in the present embodiment, the seal can be controlled more easily. Preferably, the first and second circumferential lengths are at least substantially the same, so that the sealing material is bent rather than stretched to a significant extent.

Alternatively, when the sealing material is bent or deformed, it may be desirable that the circumferential length is slightly changed, such as one side thereof being bent to cause compression and the other side thereof being stretched. In summary, it is desirable to provide a shape having a circumferential length at least close to that exhibited upon automatic "selection" of such a seal material.

A piston that can be used in such a combination is a piston that includes a deformable cavity. The receptacle may be elastically or inelastically deformable. In the last method, the walls of the chamber may be curved when moving within the chamber. The elastically deformable housing has a dimension of manufacture, about the circumferential length of the first longitudinal position of the housing, which has a reinforcement allowing high friction contraction, is also used in such combinations, and its piston has a particularly high velocity. Elastically deformable cavities are also used, having a dimension of manufacture, about the circumferential length of the second longitudinal position of the cavity, with a shell reinforcement, allowing the partial cavity walls to have different distances from the central axis of the cavity in a longitudinal cross section of the cavity.

It is clear that: depending on the combination, it is understood that one of the piston and the chamber may be stationary, the other may be moving, or both may be moving. This does not affect the functionality of this combination.

The piston may also slide on the inner and outer walls. The inner wall may be tapered and the outer wall cylindrical.

Of course, the present combination can be used for several purposes, the main problem being to provide a new attachment. This new approach meets the force requirements of the piston motion on demand. Indeed, the cross-sectional area/shape may be varied along the length of the cavity in order to accommodate the combination for a particular target and/or force. One object is to provide a pump for women and teenagers that should still provide a certain pressure. In this case, an ergonomically improved pump is required by determining at which positions of the piston a person can provide a force and thereby providing a chamber with a suitable cross-sectional area/shape.

Another use of this combination is as a shock absorber, where the area/shape determines the conditions required to translate a certain shock (force). An actuator may also be provided. In an actuator, the amount of fluid introduced into the volume may provide a different displacement of the piston before introduction of the fluid depending on the actual position of the piston.

The preferred embodiment of the piston and chamber combination is used in the case of a piston pump. This does not limit the scope of the invention of the above-mentioned application, since above all the fact that the valve arrangement of the chamber can induce movements in addition to the items and media plays a decisive role for the type of application: a pump, an actuator, a shock absorber, or an engine. In a piston pump, the medium may be compressed by the chamber and/or the piston, after which the valve may release this compressed medium from the chamber. In the actuator, the medium may be pressed into the chamber by the valving arrangement, and the chamber and/or the piston may be movable, the person causing movement of the add-on device. In the shock absorber, the chamber may be completely closed, wherein the compressed medium may be further compressed by the movement of the chamber and/or the piston. In case no compressed medium can be arranged inside the cavity, for example: the piston may be equipped with grooves capable of providing dynamic friction in order to slow the speed of movement.

Furthermore, the invention may also be used in power units where the medium is used to move a piston and/or a chamber, which may be rotated about an axis such as an electric motor. The above combinations may be used in the various applications described above and are more suitable than the piston pumps described above for other pneumatic and/or hydraulic applications.

The invention therefore also relates to a pump for pumping a fluid, which pump has:

a combination of one of the above aspects;

means for connecting to the piston at a location outside the chamber;

a fluid inlet connected to the chamber and having a valve means; and

a fluid outlet connected to the chamber.

In one case, the coupling device has an outer position in which the piston is in its first longitudinal position; there is also an inner position in which the piston is in its second longitudinal position. Such a pump may be recommended when pressurized fluid is desired.

In one case, the coupling device has an outer position in which the piston is in its second longitudinal position; there is also an inner position in which the piston is in its first longitudinal position. Such a pump may be recommended when it is only desired to transport fluid without substantial pressure.

In the case of a pump intended to be placed standing on the ground and to compress a fluid, for example compressed air, by forcing the piston/connecting device downwards, it is possible, from an ergonomic point of view, to provide the greatest force at the lowest position of the piston/connecting device/handle. In the first case, this therefore means that the highest pressure is provided there. In the second case, this only means that in the lowest position there is a maximum area and thus a maximum volume. However, since an extremely high pressure is required to open the valve of a tire in a tire-like device, it may be desirable to have a minimum cross-sectional area shortly before the lowest position of the coupling device in order to be able to generate the final pressure to open the valve, while a larger cross-sectional area allows more fluid to enter the tire.

The pump according to the invention can use substantially less force than pumps based on conventional piston-cylinder combinations, for example water pumps which can pump water from deeper places. This property is extremely important for e.g. developing countries. Also, the chamber of the present invention may have another function of pumping liquid when the pressure difference is substantially zero. A well-designed chamber can meet the physical (ergonomic) needs of the user, such as for example pressure differences: reference is made to fig. 17B and 17A, respectively. This may be accomplished through the use of a valve.

The invention also relates to a piston which is closed in a cylinder and simultaneously in a conical cylinder. The piston may/may not comprise an elastically deformable container. The resulting cavity may be one having dimensions of different/same circumferential length. The piston may comprise one of a number of piston rods.

Furthermore, the present invention relates to a shock absorber having:

a combination according to any of the above combinations;

means for connecting the piston from a position outside the chamber, wherein the connecting means has an outer position in which the piston is in its first longitudinal position; an inner position in which the piston is in its second longitudinal position.

The shock absorber may also have a fluid outlet connected to the chamber and having a valve means.

It may be recommended that the chamber and the piston form an at least substantially closed space, which contains the fluid. The fluid is compressed when the piston moves from the first position to the second position.

Of course, the shock absorber may also have means for biasing the piston towards the first position.

Furthermore, the invention relates to an actuator having:

a combination according to any of the above combinations;

means for connecting the piston to a location outside the chamber;

means for introducing fluid into the chamber to move the piston between the first and second longitudinal positions.

The actuator may have a fluid inlet connected to the chamber and may have a valve means.

There may also be a fluid outlet connected to the chamber and which may have a valve means.

In addition, the actuator may have a means for biasing the piston toward the first or second position.

The present invention relates to a motor, which comprises:

a combination according to any of the above combinations;

finally, the invention relates to a power unit which is more mobile, such as a parachute, which is a mobile power unit. Such a unit has a power source, preferably at least one set of solar cells, and a power unit, such as an electric motor, to which the present invention relates. There may now be at least one service device, such as a pump and/or any other device to which the present invention relates, which may utilise its surplus energy from a low-force device having a hybrid piston cylinder to which the present invention relates. Due to its ultra low force it is possible to transport a mobile power unit through the parachute, as the structure based on the device of the invention can be lighter than the structure based on the hybrid piston cylinder.

The various embodiments described above are presented by way of example only and should not be construed to limit the invention. Those skilled in the art will readily recognize various modifications, changes, and combinations of elements that may be made to the present invention without strictly following the exemplary embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the present invention.

Preferred embodiments of the present invention will be described hereinafter with reference to the accompanying drawings, in which:

FIG. 1A shows a longitudinal cross-section of an unmoving piston in a first longitudinal position in an unpressurized cylinder, and shows the piston in its as-produced size, and as pressurized.

FIG. 1B shows the contact pressure of the pressurized piston shown in FIG. 1A against the cylinder wall.

Fig. 2A shows a longitudinal cross-section of the piston of fig. 1 in a cylinder in a first (right) and a second (left) longitudinal position, with the piston not pressurized.

FIG. 2B shows the contact pressure acting on the cylinder wall when the piston shown in FIG. 2A is in the second longitudinal position.

Fig. 2C shows a longitudinal cross-section of the piston of fig. 1A in a second longitudinal position in a cylinder, and the piston is pressurized to the same pressure level as the one shown in fig. 1A, while showing the dimensions of the piston in the first longitudinal position (as produced).

FIG. 2D shows the contact pressure acting on the cylinder wall when the piston shown in FIG. 2C is in the second longitudinal position.

Fig. 3A shows a longitudinal cross-section of the piston shown in fig. 1 in a first longitudinal position in a cylinder, and shows the piston in its as-manufactured dimensions and the piston being pressurized when it is subjected to a pressure in the chamber.

FIG. 3B shows the contact pressure of the piston on the cylinder wall shown in FIG. 3A.

Figure 4A shows a longitudinal cross-section of an unmoving piston according to the invention in a second longitudinal position in a cylinder, and shows the piston in its as-produced size and when pressurized to a certain level.

Fig. 4B shows the contact pressure of the piston on the cylinder wall shown in fig. 4A.

Figure 4C shows a longitudinal section through an unmoving piston according to the invention, in a second longitudinal position in the cylinder, shown in its as-produced dimensions, and in a first longitudinal position, shown pressurized to the same level as shown in figure 4A.

Fig. 4D shows the contact pressure of the piston shown in fig. 4C against the cylinder wall.

Fig. 5A shows a longitudinal cross-section of the piston of fig. 4A in a second longitudinal position in the cylinder, and shows the piston in its as-produced size and when pressurized.

FIG. 5B shows the contact pressure of the piston shown in FIG. 5A against the cylinder wall.

Fig. 5C shows a longitudinal cross-section of the piston of fig. 4A in a second longitudinal position in the cylinder, and shows the piston in its as-produced size, and when pressurized under pressure from the chamber.

FIG. 5D shows the contact pressure of the piston shown in FIG. 5A against the cylinder wall.

Fig. 6A shows a longitudinal cross-section of a first embodiment of a piston with a fixed chamber of different cross-sectional area and including a fabric reinforcement portion that changes dimension radially-axially during the stroke, and showing the piston structure pressurized at the beginning and at the end of a stroke, the piston having its as-manufactured dimensions unpressurized.

FIG. 6B shows an enlarged view of the piston shown in FIG. 6A at the beginning of the stroke.

FIG. 6C shows an enlarged view of the piston shown in FIG. 6A at the end of the stroke.

Figure 6D shows a three-dimensional view of a reinforcing matrix of elastic fabric material located on the walls of the cavity as the cavity is about to expand.

Figure 6E shows the pattern of figure 6D when the cavity wall is expanded.

Figure 6F shows a three-dimensional view of a reinforcing matrix of non-elastic fabric material positioned on the walls of the cavity when the piston is about to expand.

Figure 6G shows the pattern of figure 6F when the cavity wall is expanded.

Fig. 6H shows a detailed view of the piston with fabric reinforcement.

Fig. 7A shows a longitudinal cross-section of a second embodiment of a piston with a fixed chamber of different cross-sectional area and including a fabric reinforcement that changes dimension radially-axially during the stroke ("lattice effect"), and showing the piston structure at the beginning and at the end of a stroke, pressurized, the piston having its as-manufactured dimensions unpressurized.

FIG. 7B shows an enlarged view of the piston shown in FIG. 7A at the beginning of the stroke.

FIG. 7C shows an enlarged view of the piston shown in FIG. 7A at the end of the stroke.

Fig. 8A is a longitudinal section of a third embodiment of a cavity and piston with fixed, different cross-sectional areas, the third embodiment of the piston including a fabric reinforcement that changes dimension radially-axially during the stroke (no "lattice effect"), and showing the piston structure pressurized at the beginning and at the end of a stroke, the piston having its as-manufactured dimensions.

FIG. 8B shows an enlarged view of the piston shown in FIG. 8A at the beginning of the dry stroke.

FIG. 8C shows an enlarged view of the piston shown in FIG. 8A at the end of the stroke.

FIG. 8D shows a top view of the piston of FIG. 8A with cortical reinforcing portions in planes passing through the central axis, left: in a first longitudinal position, right: in the second longitudinal position.

FIG. 8E shows a top view of the piston shown in FIG. 8A with cortical reinforcing portions in planes passing partially through the central axis and partially outside the central axis, left: in a first longitudinal position, right: in the second longitudinal position.

FIG. 8F shows a top view of the piston of FIG. 8A with cortical reinforcement in a plane that does not pass through the central axis, left: in a first longitudinal position, right: in the second longitudinal position.

Fig. 8G shows a detailed view of a piston with a fabric reinforcement.

FIG. 9A is a longitudinal section of a fourth embodiment of a chamber and piston with fixed, different cross-sectional areas, the fourth embodiment of the piston including an "octopus" type structure that limits elongation of the chamber wall by tentacles, is inflatable, and shows the piston structure pressurized at the beginning and at the end of a stroke, the piston having its as-manufactured dimensions.

FIG. 9B shows an enlarged view of the piston shown in FIG. 9A at the beginning of the stroke.

FIG. 9C shows an enlarged view of the piston shown in FIG. 9A at the end of the stroke.

Fig. 10A shows the embodiment of fig. 6, wherein the pressure inside the piston can be varied by inflating, for example, a Schrader valve provided in the handle and/or a one-way valve provided in the piston rod, for example, and wherein a closed space balances the change in piston volume during the stroke.

FIG. 10B shows an alternative sleeve to the inflation valve that can be connected to an external pressure source.

Fig. 10C shows details of the guiding aspect of the stem of the one-way valve.

Fig. 10D shows the flexible piston of the one-way valve in the piston rod.

Fig. 10E shows the embodiment of fig. 6, wherein the volume of the enclosed space of fig. 10A-10D is exchanged by a pressure source, an inlet valve for charging the piston from said pressure source and an outlet valve for submitting pressure to the pressure source, according to an enlarged detail of the valve-valve actuator combination of fig. 11D.

FIG. 10F illustrates the embodiment of FIG. 10E, showing one manipulable valve and one jet or nozzle, shown in black box.

Fig. 11A shows the embodiment of fig. 6, wherein the pressure inside the piston can be kept constant during the stroke, and wherein a second enclosed space can be inflated by means of a Schrader valve arranged in the handle, and the second enclosed space communicates with the first enclosed space by means of a piston arrangement, the piston can be inflated by means of a Schrader valve + valve actuating arrangement, the pressure of the chamber is the same as the pressure source, while the discharge valve of the chamber can be manually controlled by means of a rotatable pedal.

FIG. 11B shows a piston structure and its bearings, where the piston structure communicates between the second and first closed controls.

Fig. 11C shows an alternative piston structure that adapts to the change in cross-sectional area of the interior of the piston rod along its longitudinal direction.

FIG. 11D shows an enlarged view of the inflated configuration of the piston shown in FIG. 11A at the end of the stroke.

Fig. 11E shows an enlarged view of a bypass structure of the valve actuator for closing and opening the drain valve.

Fig. 11F shows an enlarged view of an automatic closing and opening configuration of the drain valve, showing a similar system for obtaining a predetermined pressure value in the piston (shown in phantom).

FIG. 11G shows an enlarged view of an inflation structure of the piston of FIG. 11A, including a combination of a valve actuator and a spring-force operated cap that automatically inflates the piston from the chamber to a predetermined pressure.

FIG. 11H shows a modified solution of FIG. 11G, including the combination of a valve actuator and a spring disposed below the valve actuator piston.

Figure 12 shows a configuration in which the pressure in the cavity may be dependent on the pressure in the cavity.

Fig. 13A shows a longitudinal cross-sectional view of a chamber with a flexible wall of different transverse cross-sectional area and a piston of fixed geometry, and shows the configuration of the combination at the beginning and end of the pump stroke.

Fig. 13B shows an enlarged view of the assembly structure at the beginning of a pump stroke.

Fig. 13C shows an enlarged view of the assembly structure during a pump stroke.

Fig. 13D shows an enlarged view of the assembly structure at the end of a pump stroke.

FIG. 14 shows a longitudinal cross-sectional view of a chamber with a flexible wall of different transverse cross-sectional area and a piston with variable geometry, and shows the assembly at the beginning of stroke, in stroke, and at the end of stroke.

Fig. 15A shows an example of a cross-sectional area reduction in a fourier series expansion of the pressurizing chamber when the size of the circumference is kept constant.

Fig. 15B shows a variation of the pressurizing chamber of fig. 7A, with a longitudinal cross-section adapted to the transverse cross-section designed to decrease in area as its circumference decreases approximately uniformly or to a small extent during the pumping stroke.

FIG. 15C shows a longitudinal section at G-G (dashed line) and H-H in the cross-section of FIG. 15B.

FIG. 15D shows a longitudinal section at G-G (dashed line) and I-I in the cross-section of FIG. 15C.

Fig. 15E shows another example of a cross-sectional area reduction in the fourier series expansion of the pressurizing chamber when the size of the circumference is kept constant.

Fig. 15F shows an example of an optimal curve shape of a cross section in a certain case.

Figure 16 shows a combination in which the piston moves in a cylinder with a conical centre.

Figure 17A shows an ergonomically optimal chamber for aspiration purposes and manual manipulation.

Fig. 17B shows the corresponding stroke force profile.

Fig. 18A shows an example of a mobile power unit, suspended under a parachute.

Fig. 18B shows a detailed view of the mobile power unit.

Detailed Description

Fig. 1A shows a longitudinal section through an unmoving piston 5 which is not pressurized at a first longitudinal position of an unpressurized chamber 1 and which has a circular cross-section with a constant radius at that position. The piston 5 may have a size, for example manufactured, which is approximately the diameter of the chamber 1 at the first longitudinal position. Showing the piston 5 when pressurized to a certain pressure level^*At the piston 5^*The internal pressure creates a certain contact length.

FIG. 1B shows the piston 5 shown in FIG. 1A^*The contact pressure of (a). Piston 5^*It may be blocked at this longitudinal position.

Fig. 2A shows a longitudinal section of an unmoving piston 5 in a first longitudinal position of an unpressurized chamber 1 and a piston 5' in a second longitudinal position of the unpressurized chamber 1, with the chamber having a circular cross-section with a constant radius at both the first and the second longitudinal position. The piston 5 may have a size, for example manufactured, which is approximately the diameter of the chamber 1 at the first longitudinal position. The piston 5' shows the piston 5 arranged unpressurized in the smaller cross-section of the second longitudinal position.

Fig. 2B shows the contact pressure of the piston 5' at a second longitudinal position on the cylinder wall. The piston 5' can be snapped in at this longitudinal position.

Fig. 2C shows a longitudinal section of an unmoving piston 5 in a first longitudinal position of an unpressurized chamber 1 and a piston 5' in a second position of the unpressurized chamber 1, with the chamber having a circular cross-section with a constant radius at both the first and the second longitudinal position. The piston 5 may have a size, for example manufactured, which is approximately the diameter of the chamber 1 at the first longitudinal position. Piston 5'^*A piston 5 is shown which is pressurized to the same pressure level as the one shown in fig. 1A and which is arranged in a smaller cross-section at a second longitudinal position.

FIG. 2D shows piston 5'^*Contact pressure at a second longitudinal location on the cylinder wall. Piston 5'^*It is possible to jam at this longitudinal position: the friction force may be 72 kg.

FIG. 3A shows the piston 5 shown in FIG. 1A and the piston 5 pressurized to the same level as shown in FIG. 1A^*Of the same pressure level, a deformed piston 5 "^*. The deformation is caused by the chamber 1 when the piston may not have means to limit the elongation^*Caused by the pressure in (b), the means shown to limit elongation are mainly in the direction of the meridian (longitudinal direction of the cavity).

Fig. 3B shows the contact pressure. Piston 5 "^*It may be blocked at this longitudinal position.

Fig. 4A shows a longitudinal section through a piston 15 in a second longitudinal position of an unpressurized chamber 10, the piston having a circular cross-section. The piston 15 may have a size, for example manufactured, which is approximately the diameter of the chamber 10 at the second longitudinal position. Piston 15'^*A deformed piston 15 is shown pressurized to a certain level. The deformation is due to the fact that the young's modulus of elasticity in the hoop direction (in the direction of the cross-sectional plane of the cavity) is chosen to be lower than in the meridional direction (in the longitudinal direction of the cavity).

FIG. 4B is shown in the figurePlug 15'^*The contact pressure on the wall. This produces a suitable friction force (4.2 kg) and a suitable seal.

FIG. 4C shows a longitudinal cross-section of the piston 15 at a second longitudinal position (e.g., manufactured size) of the unpressurized chamber 10, and when pressurized 15 "^*(piston 15 "^*Can be provided with a piston 15'^*At the second longitudinal position of the chamber 10 (same pressure in fig. 4A) in the first longitudinal position. Here also deformations in the ring direction and meridian direction are present.

FIG. 4D shows a piston 15 "^*The contact pressure on the wall. This produces a suitable friction force (0.7 kg) and a suitable seal.

Thus, a piston comprising an elastically deformable chamber can be moved sealingly from a region of smaller cross-sectional area to a region of larger cross-sectional area, and at the same time with the same internal pressure (within the limits of the cross-sectional diameter selected for this test).

FIG. 5A shows piston 15 (as manufactured to size) and piston 15 'at a second longitudinal position of unpressurized cavity 10'^*Longitudinal section of (a). Piston 15'^*A deformed configuration of the piston 15 is shown when the piston 15 is pressurized. Piston 15, 15'^*Has been attached at the lower end to an imaginary piston rod to prevent movement of the piston during application of the chamber pressure.

FIG. 5B shows the piston 15 'of FIG. 5A'^*The contact pressure of (a). It is low enough to allow movement (4.2 kg friction) and is suitable for sealing.

FIG. 5C shows the piston 15 (as sized) and the chamber 10 being pressurized^*At a second longitudinal position of the piston 15 which is pressurized and deformed by the pressure of the chamber "^*Longitudinal section of (a). Piston 15, 15'^*Has been attached at the lower end to an imaginary piston rod to prevent movement of the piston during application of the chamber pressure. Deformed piston 15 "^*Approximately twice as large as the undeformed piston 15The sample length is long.

FIG. 5D shows the piston 15 shown in FIG. 5C "^*The contact pressure of (a). It is low enough to allow movement (3.2 kg friction) and is suitable for sealing.

Thus, it can be sealingly displaced (at least at the smallest cross-section) when a chamber pressure is exerted on the piston comprising a pressurized elastically deformable chamber. Such a situation may need to be limited due to the large elongation resulting from the applied cavity force.

Fig. 6-9 relate to elongation limitations on the piston skins that result in a contact area that is small enough to enable proper sealing and low enough friction to allow movement of the piston. This includes a limitation of the elongation in the longitudinal direction when the cavity is subjected or not to a pressure in the cavity and allows an expansion in the transverse direction when moving from a second to a first longitudinal position of the cavity and in particular a contraction when moving from the opposite direction.

The elongation of the walls of the cavity-containing piston in the longitudinal direction can be limited by several methods. It may be achieved by using a reinforced part of the wall of the chamber, for example a fabric and/or a fibre. It can also be realized by an expansion body which is arranged inside the cavity of the cavity and has expansion limitation, and the expansion body is connected to the wall of the cavity. Other methods may be used, such as pressure manipulation of the cavity between the two walls of the chamber, pressure manipulation of the space above the chamber, etc. The reinforcing portion may also be located outside the piston.

The expansion properties of the wall may depend on the type of elongation limit used. Furthermore, the piston, which is kept moving on the piston rod during expansion, can be guided by a mechanical stop. The positioning of such a stop may depend on the use of the piston-chamber combination. It may also be the case that the receiving space is guided on the piston rod and at the same time expands and/or is subjected to external forces.

Various types of flow regimes, combinations of compressible and incompressible media, only compressible media or only incompressible media may be used.

The change in size of the cavity from the region where the cavity has its smallest cross-sectional area, e.g. the manufactured size, to the cavity expanding at the region where the cross-sectional area is largest may be considerable, so that communication of the cavity in the cavity with a first closed space, e.g. in the piston rod, may be required. The first enclosed space may also be pressurized in order to maintain the pressure in the chamber, and also during a change of the volume of the chamber of the receptacle. Pressure management of at least the first enclosed space may be required.

Fig. 6A shows a longitudinal cross section of cavity 186 with a recessed wall 185 and an inflatable piston including a cavity 208 at a first longitudinal location in cavity 186 and the same cavity 208' at a second longitudinal location in cavity 186. The cavity 186 has a central, central axis 184. The pocket 208' is shown in its as-manufactured size and has a fabric reinforcement 189 in the skin 188 of the wall 187. In the stroke beginning at the second longitudinal position of the cavity 186, the wall 187 of the cavity expands until a stop structure, which may be a fabric reinforcement 189 and/or a mechanical stop 196 outside the cavity 208 and/or another stop structure, stops the movement in the stroke. And thus expansion of the cavity 208. Depending on the pressure in the cavity 186, the cavity walls may still elongate longitudinally due to the pressure in the cavity 186. While the first main function of the reinforcing portion is to limit the longitudinal extension of the wall 187 of the cavity 208. This results in a small contact area 198. The second primary function of the fabric reinforcement portion 198 is to allow contraction when the cavity is moved to the second longitudinal position (and vice versa when expansion is necessary). During the stroke, the pressure inside the chambers 208, 208' may be kept constant. This pressure is dependent on the change in volume of the chambers 208, 208', and hence the change in circumferential length of the cross-section of the chamber 186 during the stroke. The pressure may also be varied during the stroke. The pressure may also vary during the stroke with or without dependence on the pressure in the chamber 186.

Fig. 6B shows a first embodiment of the extended piston 208 at a first longitudinal position of the cavity 186. The cavity wall 187 is formed of a skin 188 made of a flexible material (e.g., rubber type or the like) with a fabric reinforcement 189 that allows the cavity wall to expand. The direction of the fabric reinforcement portion is offset by 54 ° 44' from the central axis 184 (the braid angle). The dimensional change of the piston in the stroke as it is pulled need not produce an identical shape. The wall thickness of the cavity wall may be thinner due to expansion than the wall thickness of the cavity when in the second longitudinal position of the cavity 186, as produced. A barrier layer 190 may be provided on the inside of the wall 187. It is tightly squeezed in the lid 191 in the top and lid 192 in the bottom of the cavities 208, 208'. Details of the lid are not shown and various methods of assembly may be used which may enable them to adapt to variations in the wall thickness of the receptacle. Both caps 191, 192 can translate and/or rotate on the piston rod 195. These movements may be achieved by various methods, such as different types of bearings (not shown). The cover 191 in the top can move up and down. A stop 196 on the piston rod 195 outside the cavity 208 limits the upward movement of the cavity 208. The cover 192 in the bottom can only move downward because the stop 197 prevents its upward movement (this embodiment is considered to be used in a piston chamber arrangement where there is pressure below the piston in the chamber 186). Other stop arrangements may be used in other types of pumps, such as double work pumps, vacuum pumps, etc., and are dependent only on design specifications. Other arrangements for allowing relative movement of the piston with respect to the piston rod and/or for limiting such relative movement are possible. The adjustment of the sealing force may comprise a combination of incompressible fluid 205 and compressible fluid 206 (both may also be used separately) inside the chamber, while the chamber 209 of the chamber may be in communication with a second chamber 210, and said second chamber 210 comprises a spring force operated piston 126 inside the piston rod 195. Fluid can flow freely through the bore 201 through the wall 207 of the piston rod. The second chamber may also be in communication with a third chamber (see fig. 12), and the pressure within the chamber may also be dependent on the pressure in chamber 186. The chamber may be inflatable by a piston rod 195 and/or by communication with the chamber 186. O-rings or

similar seals

202, 203 in the lid in the top and in the lid in the bottom seal the

lids

191, 192 against the piston rods, respectively. At the end of the piston rod 195, a cap 204, shown as a threaded assembly, screws the piston rod. A comparable stop could be provided elsewhere on the plunger rod, depending on the desired movement of the chamber wall. The contact area 198 between the chamber wall and the chamber wall.

FIG. 6C shows the piston of FIG. 6B in a second longitudinal position of the chamber, wherein the piston has its as-manufactured dimensions. The cover 191 in the top portion is moved a distance a' from the stop 196. The spring force operated valve piston 126 moves a distance b'. The bottom cover 192 is shown adjacent the stop 197 and if there is pressure in the cavity 186 below the piston, the cavity 186 presses against the stop 197. A compressible fluid 206 'and a non-compressible fluid 205'.

Figure 6D is a three-dimensional view and shows a reinforcing matrix of fabric material that allows for elastic expansion and contraction of the walls of the cavities 208, 208' when sealingly moved within the cavity 186. The web material may be elastic and arranged with the individual layers overlapping each other. The layers may also be arranged to be woven together. The angle between the two layers may differ by 54 deg. 44'. When the material type and thickness of all the layers are the same and the number of layers is averaged, while the size of the slits in each direction is equal, the expansion and contraction of the cavity walls is equal in the XYZ directions. As the expansion of the slits ss and tt, respectively, in each direction of the substrate becomes greater, their contraction will become smaller. Since the material of the wire may be elastic, another device is sufficient to stop the expansion, e.g. a mechanical stop. This may be the wall of the cavity and/or a mechanical stop shown on the plunger rod, as shown in fig. 6B.

Fig. 6E is a three-dimensional view and shows the reinforcement matrix of fig. 6D, which has been expanded. The slots ss 'and tt' are larger than the slots ss and tt. The result of the shrinkage is a matrix as shown in fig. 6D.

Fig. 6F is a three-dimensional view and shows a reinforcing matrix of textile material that may be made of inelastic threads (but which are elastically bendable) and arranged in separate layers overlapping each other or interwoven with each other. Expansion is possible because when the pocket is sized, and is pressurized when in the second longitudinal position of the chamber, additional length of each coil 700 is available. The slots ss "and tt" are in their respective directions. The inelastic material (but resiliently bendable) may limit the maximum expansion of the wall 187 of the receptacle 217 when the receptacle wall is expanded. This is sufficient to stop the movement of the cavity 217 on the piston rod 195, for example by means of the stop 196, whereby the seal can be maintained. The absence of such a stop 196 may create a valve.

FIG. 6G is a three-dimensional view and shows the reinforcement matrix of FIG. 6F, which has been expanded. The slits ss '"and tt'" are larger than the slits ss "and tt". The result of the shrinkage is a matrix as shown in fig. 6F.

Figure 6H shows three stages I, II and III of the manufacturing process of a piston comprising an elastically deformable cavity. A rubber pad 601 is provided on the bar 600, above which a reinforcing pad 602, such as those according to fig. 6E-G, is provided. Another rubber pad is arranged above the last pad. One or more covers 604 are provided between the pad 601 and the rod. All the covers slide over the bar 600. The rod 600 may be hollow and may be connected to more than one source of high pressure vapor. Stage II: the pressurized vapor enters the interior cavity 608 of the furnace 606 through an outlet 605, which may be provided at the end of the rod. A piece of integral rubber/reinforcing mat 607 may be cut and carried over the rod 600 into the cavity 608. The cavity is then closed and pressurized vapor is injected into the cavity. Vulcanization then occurs, including mounting the cavity walls to the lid 604. The pad may have a curved shape. After vulcanization, the inner chamber is opened and the chamber with the dimensions as produced is pushed out (III). In order to utilize the cure time of the piston to produce other pistons, a variety of methods may be used. Expansion of the rubber mat 607 (intact, including the fabric reinforcement) may be performed prior to vulcanization. The upper portion of the bar 600 may be divided into sections each having approximately the height of the production sized cavity. Each portion is separated from the main shaft prior to entering the lumen. And/or, there may be multiple lumens at the end of the production feed line, each of which is positioned to receive and vulcanize a complete mat 607. This may be accomplished by rotating and/or translating the internal chamber toward and from the end of the production feed line. It is also possible to integrate a plurality of vulcanisation chambers into the end of the production feed line.

Fig. 7A shows a longitudinal cross section of a cavity 186 with a recessed wall 185 and an inflatable piston comprising a cavity 217 at a first longitudinal position of the cavity and the same cavity 217' at a second longitudinal position. The receptacle 217' is shown in its as-manufactured size.

Fig. 7B shows the expanded piston 217 in a first longitudinal position of the chamber. The cavity wall 218 is made of a flexible material (which may be, for example, of the rubber type or the like) and is formed with a skin 216 having a fabric reinforcement 189 according to the "Trellis Effect" which allows the cavity wall 218 to expand, the direction of the fabric being offset by 54 ° 44' with respect to the central axis 184 (the braiding angle). The contact region 211 is located between the wall 218 of the receptacle 217 and the wall 185 of the chamber 186. The thickness of the chamber wall may be reduced by expansion but need not be thinner than the thickness of the chamber wall at the second longitudinal position, as produced. A barrier layer 190 may be provided on the inside of the wall 187. It is tightly pressed against the cavity 217. 217' in a lid 191 in the top and a lid 192 in the bottom. Details of the lid shown are not shown and various methods of assembly may be used which may lend themselves to accommodate variations in the wall thickness of the receptacle. Both caps 191, 192 can translate and/or rotate on the piston rod 195. These movements may be achieved by various methods, such as different types of bearings (not shown). The cover 191 in the top can move up and down until the stop 214 limits its movement. The cover 192 in the bottom can only move downward because it is prevented from moving upward by the stop 197 (this embodiment can be considered to be used in a piston chamber arrangement where there is pressure below the piston in the chamber 186). Other stop arrangements may be used in other types of pumps, such as double-working pumps, vacuum pumps, etc., and are dependent only on design specifications. Other arrangements for allowing relative movement of the piston with respect to the piston rod and/or for limiting such relative movement are possible.

During the stroke, the pressure inside the chambers 217, 217' remains constant. It is also possible that the pressure varies during the stroke. The adjustment of the sealing force may comprise a combination of incompressible fluid 205 and compressible fluid 206 (both may also be used separately) inside the chambers, while the chambers 215 of the chambers 217, 217' may be in communication with a second chamber 210, and said second chamber 210 comprises a spring force operated piston 126 inside the piston rod 195. Fluid can flow freely through the bore 201 through the wall 207 of the piston rod. The second chamber may also be in communication with a third chamber (see fig. 10), and the pressure within the chamber may also be dependent on the pressure in chamber 186. The chamber may be inflatable by a piston rod 195 and/or by communication with the chamber 186. O-rings or

similar seals

202, 203 in the lid in the top and in the lid in the bottom seal the

lids

191, 192 against the piston rods, respectively. At the end of the piston rod 195, a cap 204, shown as a threaded assembly, screws the piston rod.

Fig. 7C shows the piston of fig. 7B in a second longitudinal position of the cavity 186 with a small contact area 211'. The cover 191 has moved a distance c' from the stop 216. The spring force operated valve piston 126 moves a distance d'. The bottom cover 192 is shown adjacent the stop 197 and if there is pressure in the cavity 186, the cover 192 presses against the stop 197. Compressible fluid 206 'and incompressible fluid 205' may change volume in the cavity.

Fig. 8A, B, C relates to the retraction of the piston which is the same as in fig. 7A, B, C except that the reinforcement portions comprise any kind of reinforcement means which is bendable and which may be in the form of reinforcement "posts" and which do not cross each other. This form may be one parallel to the central axis 184 of the cavity 186 or a form of a portion of the reinforcing apparatus in a plane through the central axis 184.

Fig. 8A shows an inflatable piston comprising a cavity 228 at a first longitudinal position of the cavity 186 and the same cavity 228' at a second longitudinal position of the cavity 186, the cavity being pressurized, wherein it is not pressurized for its manufactured size.

Fig. 8B shows the pocket 228 at a first longitudinal position of the cavity 186. The wall 21 of the cavity comprises an elastic material 222, 224 and a reinforcement 223, such as fibers. An impermeable layer 226 may be present. The area of contact between the receptacle 228 and the wall 185 of the chamber 186.

Fig. 8C shows the pocket 228' at a second longitudinal position of the cavity 186. The contact region 225' is slightly larger than the contact region 225. The top cover 191 has moved a distance e' from the stop 214.

Fig. 8D shows a top view of pistons 228 and 228 'having reinforcing means 223 and 223', respectively, at first and second longitudinal positions of cavity 186.

Fig. 8E shows a top view of pistons similar to pistons 228 and 228 'having, as further examples, stiffening means 229 and 229' at first and second longitudinal positions of the cavity 186, respectively. A portion of the reinforcing portion is not in a plane through the central axis 184 in the longitudinal direction of the cavity 186.

Fig. 8F shows a top view of pistons similar to pistons 228 and 228 'having reinforced portions 227 and 227' on the pocket walls in a plane that does not pass through the central axis 184 of the cavity 186. In one stroke, the walls of the cavity rotate about a central axis 184.

Fig. 8G schematically shows how the fibers 802 are installed in the lumen 801 of the cap 800. This can be achieved by rotating the cap and fiber about the central axis 803, which have respective velocities, while the fiber 802 is pushed toward and into the lumen 801.

Fig. 9A shows a longitudinal cross section of cavity 186 with a projecting wall 185 and an inflatable piston including a cavity 258 at the beginning of a stroke and the same cavity 258' at the end of the stroke. Plenum 258' is in a second longitudinal position.

Fig. 9B shows a longitudinal cross section of a piston 258 having a reinforced skin, and the skin of the piston is reinforced by at least elastically deformable support members 254, the support members 254 being rotatably fixed to a common member 255 and connected to a skin 252 of the piston 258, 258'. These supports are in tension and, depending on the stiffness of the material, they have a certain maximum elongation length. This extreme elongation length limits the elongation of the skin 252 of the piston. The common member 255 may slide on the piston rod 195 using a slide 256. As for the others, the structure is similar to that of the pistons 208, 208'. And contact region 253.

Fig. 9C shows a longitudinal cross section of the piston 258'. Contact region 253'.

Fig. 10-12 relate to pressure manipulation in a chamber. The pressure manipulation of a piston comprising an inflatable volume and an elastically deformable wall is an important part of the piston-chamber structure. Pressure management is necessary to maintain the pressure in the chamber to maintain the seal at an appropriate level. This means that during each stroke of volume change of the chamber, and from a long term point of view, leakage from the chamber may reduce the pressure in the chamber, which may affect the ability to seal. Fluid flow may be the solution. When the volume of the chamber changes during a stroke, flow into or out of the chamber, and/or as such to the chamber (inflate).

The change in volume of the receptacle may be balanced with a change in volume of a first enclosed space which communicates with the receptacle, for example through an aperture provided in the piston stem. The pressure can also be equalized at the same time and this can be achieved by a spring-force operated piston which can be arranged in the first closed space. The spring force may be generated by a spring or a pressurized enclosure, such as a second enclosure in communication with the first enclosure through a pair of pistons. Any type of force transmission may be provided by each piston, for example, by the combination of the second enclosed space with one of the pistons, such that when the pair of pistons move into the first enclosed space (e.g., when fluid flows from the first enclosed space into the chamber), the force acting on the pistons in the first enclosed space remains equal and the force acting on the pistons in the second enclosed space decreases. This means that the rule of constant p.V is well followed in the second enclosed space.

Pressure regulation in the cavity of the chamber during all or part of the stroke may also be achieved by communication of the cavity and the chamber cavity. This has been described in WO00/65235 and WO 00/70227.

The chamber may be inflated by a valve in the piston and/or by the piston handle. The valve may be a one-way valve or an inflation valve (e.g., a Schrader valve). The chamber may be inflated by a valve in communication with the chamber. It is preferred if an inflation valve, a Schrader valve, is used because of its safety against leakage and its ability to control various fluids. To enable inflation, a valve actuator may be required, such as the one disclosed in WO99/26002 or US5,094,263. The advantages of the valve actuator of WO99/26002 are: the inflation can be performed with very little force, and is therefore very practical for manual inflation. Further, the valve is combined with a spring force operated valve spool, which automatically closes when the level of isostatic pressure is reached.

If the flow of pressurized volume from the enclosed space to the receptacle (or vice versa) is substantial, it is preferred to have a pressure/volume source having a volume greater than the volume of the enclosed space and having a pressure level equal to, lower than or higher than the pressure in the receptacle. In the last-mentioned case, the volume of the pressure source is reduced compared to a pressure source having a pressure level equal to the pressure in the volume.

In the case where the pressure level of the pressure source is higher than the pressure in the chamber, it is desirable that the flow between the pressure/volume source and the chamber during the stroke is governed by a valve arrangement. These valves have a spring force operated core pin which is actuated. The actuator opens/closes the valve, changing flow on average continuously. An example is a similar configuration, the pressure drop due to leakage, which is used to inflate the chamber (see next page). Other valve types and valve control methods are also possible. This may also be a method of continuously maintaining the pressure level in the chamber at a certain level.

A valve is in communication with the chamber and automatically inflates the chamber when the pressure in the chamber is less than the pressure in the chamber. When this is not the case, such higher pressure may be temporarily created by closing a drain valve adjacent the second longitudinal position of the cavity in the chamber. Such closing and opening may be done manually, for example by a pedal which opens a passage communicating with a space between the valve actuator (WO 99/26002) and the Schrader valve. When the passageway is open, the valve actuator can move but there is a lack of force to depress the valve core pin so that the Schrader (Schrader) valve may not open and thus the chamber may be closed and any high pressure thereof may be established to enable inflation of the chamber. When the passage is closed, the actuator operates as disclosed in WO 99/26002. An operator may use a pressure gauge, such as a manometer, to sense the pressure in the chamber. The opening and closing of the drain valve may also be done automatically. This may be accomplished by various types of devices that initiate closing of the drain valve in response to any type of signal generated by measuring a pressure below a predetermined value.

The automatic inflation of the chamber to a certain predetermined value may be achieved by a combination of a valve in communication with the chamber and e.g. a release valve in the chamber. It is released at a certain predetermined pressure value, for example to the space above the cavity or to the cavity. Another alternative is: the valve actuator described in WO99/26002 may be opened first after a predetermined pressure value has been reached, for example by coupling it with a spring. Another alternative is: when the pressure reaches a value exceeding a predetermined value, the opening to the valve actuator is closed, for example by a spring-operated piston or cap. Alternatively, by incorporating the piston 292 of fig. 11e with the device, the piston thus opens the channel 297 (not shown) when a certain pressure is reached.

Fig. 10A shows a piston-chamber system according to fig. 6A-C with a piston comprising a cavity 208, 208' and a chamber 186 with a central axis 184. The inflation and pressure management described herein may also be used with other pistons that include a chamber. The chambers 208, 208' may be inflated via a valve 241 provided in the handle 240 and/or a valve 242 provided in the piston rod 195. If instead of a handle, a rotating shaft is used, for example, it may be hollow and communicate with a Schrader valve, for example. Valve 241 may be an inflation valve, such as a Schrader valve, which includes a sleeve 244 and a valve spool 245. The valve in piston rod 195 may be a one-way valve and have a flexible piston 126. The cavity between the one-way valve 242 and the cavity 209 of the chambers 208, 208' is described above as the "second" cavity 210. A pressure gauge 250 allows control of the pressure inside the chamber (not shown in further detail). The pressure gauge may also be used to control the pressure in the cavity 186. Chamber 209, which may also be the chambers 208, 208', is provided with a release valve (not shown) which can be adjusted to a predetermined pressure value. The released fluid may be directed to cavity 209 and/or space 251.

Fig. 10B shows an alternative form of inflation valve 241. Instead of an inflation valve 241 in the handle 240, only a sleeve 244 is provided, without a valve cartridge 245, the sleeve 244 being connectable to a pressure source.

Fig. 10C shows details of the bearing 246 of the stem 247 of the check valve 126. Bearing 246 includes longitudinal channels 249 that allow fluid to pass around rod 247. The spring 248 can exert a pressure on the fluid in the second chamber 210. A stopper 249.

Fig. 10D shows details of the flexible piston 126 of the one-way valve 242. The spring 248 maintains the pressure on the piston 126.

FIG. 10E shows a pressure source 701, which may have a pressure exceeding the pressure level in the cavity. An inlet valve 702 having, for example, a valve actuator 703 (configuration 709 shown is similar to that of fig. 11E (292, 297)), and an outlet valve 704 having, for example, a valve actuator 705 (configuration 711 shown is similar to that of fig. 11E (292, 297)). Space 710 is connected to cavity 707 while space 712 is connected to cavity 708. The

valves

702 and 704 may be mounted on a piston rod 706, the upper part of which may be divided into two chambers 707 and 708.

FIG. 10F shows the configuration of FIG. 10E, wherein two black boxes are shown each having a valve manager that can be controlled by an external signal. Palm rest 715 may receive pressure signals 716 and 717, respectively, from different longitudinal positions of the interior of the piston within the cavity. The palm 715 may send signals 718 and 719 to an actuator 722 of the outlet valve manager 720 and an actuator 723 of the inlet valve manager 721, respectively. The valves and valve master managers may be similar to those shown in fig. 11F.

Fig. 11A shows a piston-chamber system according to fig. 6A-C with a piston comprising a

chamber

248, 248 having the same central portion as the chambers 208, 208' and a chamber 186 having a central axis 184. The inflation and pressure management described herein may also be used with other pistons that include a chamber. The chambers 248, 248' may be inflated through a valve in communication with the chamber 186. The valve may be a one-way valve 242 according to fig. 10A, D, or it may be an inflation valve, preferably a Schrader valve 260. The first enclosed space 210 communicates with the chamber 209 in the chamber via an aperture 201, while the first enclosed space 21O communicates via a piston arrangement with a second enclosed space 243, which second enclosed space 243 may be inflated by means of an inflation valve, such as a Schrader valve 241, which may be provided in the handle 240. The valve includes a spool 245. If the handle is not used, but for example a rotating shaft, it may be hollow and a Schrader valve (not shown) communicates with the passage. The Schrader valve 260 is provided with a valve actuator 261 according to WO 99/26002. The bottom 262 of the chamber 186 may be provided with a drain valve 263, for example a Schrader valve, which may be equipped with a further valve actuator 261 according to WO 99/26002. To manually control the drain valve 263, the bottom 262 may be fitted with a pedal 265, said pedal 265 being rotatable about an axis 264 on the bottom 262 by an angle α. The pedal 265 is connected at its top by a shaft 266 to a piston rod 267 in a non-circular hole 275. The bottom 262 has a suction valve 269 (not shown) for the chamber 186. The spring 276 (schematically depicted) holds the pedal 265 in its initial position 277, where the drain valve remains open. At stop position 277 of pedal 265, the drain valve remains closed. An outlet channel 268.

Fig. 11B shows a detail of the communication between the first enclosed space 210 and the second enclosed space 243 by a pair of

pistons

242, 270. The piston rods 271 of the pair of pistons are guided by a bearing 246. Longitudinal conduits 249 in the bearing 246 allow fluid to be delivered from the gap between the bearing 246 and the

pistons

242 and 242. A spring 248 may be provided. A piston rod 195 having piston-type cavities 248, 248' with an inner wall 194.

Pistons

242, 270 are sealed against inner wall 194.

Fig. 11C shows an alternative wall 273 of the piston rod 272 of the piston-type cavities 248, 248' which is at an angle β to the central axis 184 of the cavity 186. The piston 274 is schematically depicted and the piston 274 can itself accommodate changes in the cross-sectional area of the interior of the piston rod 272.

Fig. 11D shows the piston 248' with a housing 280 disposed thereon. The housing includes a Schrader valve 260 with a core pin 245. Valve actuator 261 is shown depressing core pin 261 while fluid may enter valve 260 through

channels

286, 287, 288 and 289. Piston ring 279 may seal against wall 285 of inner cylinder 283 when core pin 245 is not depressed. The inner cylinder 283 may be sealingly enclosed between the housing 280 and the cylinder 282 by

seals

281 and 284. A cavity 186.

Fig. 11E shows the construction of the drain valve 263 with a core pin 245, and is shown depressed by the valve actuator 261. Fluid may flow through the

channels

304, 305, 306, and 307 to the open valve. The inner cylinder 302 is sealingly enclosed between the housing 301 and the cylinder 303 by

seals

281 and 284. A passage 297 having a central axis 296 is provided through the walls of the inner cylinder 302, the cylinder 303 and the housing 301. The opening 308 of the channel 297 at the outside of the housing 301 is provided with a widened portion 309 which enables the piston 292 to be sealed in a closed position 292' by a top portion 294. The piston 292 is movable in another channel 295, which channel 295 may have the same central axis 296 as the channel 297. Bearings 293 for the piston rods 267 of the pistons 292. The piston rod 267 can be connected to a pedal 265 (fig. 11A) or other actuator (shown schematically in fig. 11E).

FIG. 11F shows the piston 248' and inflation structure 368 as shown in FIG. 11D, except that structure 369 is used to control the drain valve of FIG. 11E. The inflation structure 368 now also includes structure 370 for controlling the valve of fig. 11E. This is achieved by closing the valve when a predetermined pressure is reached and opening the valve when the pressure is below a predetermined value. A signal 360 is processed in a transducer 361 which sends a signal 362 to an actuator 363, the actuator 363 actuating the piston 292 via an actuating device 364.

The structure 369 controlling the closing and opening of the drain valve 263 may be controlled by a further actuator 363 activated by a signal 365 from the transducer 361, through the device 367, when the working pressure of the chamber is lower than a predetermined pressure value in the piston. Measurement of a signal 371 to transducers 361 and/or 366 in the chamber automatically detects whether the actual pressure in the chamber is below the working pressure of the piston. This may be particularly useful when the piston pressure is below a predetermined pressure.

Fig. 11G schematically shows the caps 312, 312' with a spring 310 connected to the housing 311 of the valve actuator 315. The spring 310 may keep the opening 314 tightly closed. The contact area 313 of the cap 312 with the cylinder 282 (fig. 11D). As the force on the cover 312 from the chamber increases, the cover will move to the position shown by cover 312' until the medium/media passing through the chamber equalizes the force on the cover. The spring 310 may determine the maximum amount of pressure to depress the spool pin 245. A Schrader (Schrader) valve 260.

Fig. 12 shows an elongated piston rod 320, in which a pair of

pistons

321, 322 are arranged at the ends of a piston rod 323, which is movable in a bearing 324.

Fig. 13A, B, C shows a pump in combination with a pressurizing chamber with walls that are resiliently deformable and have different transverse cross-sectional areas and a piston with a fixed geometry. In a housing, such as a cylinder of fixed geometry, an inflatable cavity is provided which is inflatable by a fluid (a non-compressible and/or a compressible fluid). The housing may also be omitted. The inflatable wall includes, for example, a liner-fiber-covering composition or further a barrier skin. The angle of the piston sealing surface is slightly larger than the corresponding angle of the chamber wall, relative to an axis parallel to the motion. This difference between the two said angles and the fact that the temporary deformation of the wall occurs slightly delayed in the action of the piston (by providing for example a viscous incompressible fluid in the chamber wall and/or correctly adjusting load adjusting means similar to those already shown for the pistons) provides a sealing lip whose distance to the central axis of the chamber can be varied during the movement between the two pistons and/or the chamber positions. This provides a change in cross-sectional area over a stroke, thus providing a programmable operating force. The cross-section of the piston in the direction of movement may also be the same or at a negative angle to the wall of the chamber, in which case the "nose" of the piston may be rounded. In the last-mentioned case, it may be more difficult to provide a varying cross-sectional area and thus a designable force. The walls of the chamber may be provided with all the load adjusting means shown, such as one shown on fig. 12B, and, if desired, with shape adjusting means. The speed of the piston in the cavity may have an effect on the sealing.

Fig. 13A shows the piston 230 at four piston positions in the cavity 231. A shell 234 of fixed geometry is disposed around an inflatable wall. Within the wall 234, a compressible fluid 232 and an incompressible fluid 233 are provided. A valve structure (not shown) for wall inflation may be provided. The shape of the piston on the non-pressurized side is only an example to illustrate the principle of the sealing lip. In the transverse cross-section shown, the distance between the sealing lip at the end of the stroke and at the beginning of the stroke is approximately 39%. The shape of the longitudinal cross-section may be different from that shown.

Fig. 13B shows the piston after the start of a stroke. The distance from the seal lip 235 to the central axis 236 is z₁(ii) a . The angle between the piston seal lip 235 and the central axis 236 of the cavity is ξ. The angle between the cavity wall and the central axis 236 is v. Angle v is shown to be less than angle xi. The seal lip 235 is disposed at an angle V that becomes as large as the angle ξ.

Other embodiments of the piston are not shown.

Fig. 13C shows the piston in one stroke. The foot separation from the seal lip 235 to the central axis 236 is z₂The distance is less than z₁；

Fig. 13D shows the piston almost in the end of the stroke. The distance from the seal lip 235 to the central axis 236 is z₃The distance is less than z₂。

Figure 14 shows a combination of a chamber wall and a piston with 2-28 variable geometries, adapted to adapt to each other during the pump stroke to seal continuously. It has its as-manufactured dimensions at a second longitudinal position of the cavity. The chamber is shown in fig. 13A, where it is only with an incompressible medium 237, and piston 450 is at the beginning of a stroke, while piston 450' is shown just before the end of a stroke. Likewise, all other embodiments of pistons that can vary in size may also be used herein. Proper selection of the piston speed and viscosity of the medium 237 may have a positive effect on operation. The longitudinal cross-sectional shape of the cavity shown in fig. 14 may also be different.

Fig. 15A-F show examples of cavities having different sized cross-sections with a fixed circumferential length dimension. This is another way of solving the piston clogging problem of the cited WO 00/70227. In the specific cavity, when the reinforced part of the skin layer allows the cavityPortions of the wall (which in longitudinal section of the cavity are at different distances from the central axis of the cavity) may be used, for example the position of the reinforced portion of fig. 8D is substantially parallel to the central axis of the cavity, and the piston of claim 1 works well when the reinforced portion is constituted by, for example, elastic threads (fig. 6D, 6E) or by those shown in fig. 6F, 6G (allowing each to have independent dimensions). Such as those shown in fig. 9A, 9B may also operate well. A plunger comprising an inelastically or elastically deformable cavity dimensioned approximately the same length as the perimeter of the cavity at a first longitudinal position has a reinforced portion which allows contraction with high friction to move unobstructed in the cavity and to block within the cavity when the cross-sections have different perimeter dimensions. If the weave angle of the reinforcing portion of the pockets is changed to 54 deg. 44', the elastically deformable pockets become inelastically deformable, i.e. flexibly deformable, but they do not block in these pockets because they bend. If the cross-sectional area of the piston and/or the chamber is continuous between two positions in the direction of movement and still so large, this may result in leakage. It is advantageous to minimize the variation of other parameters of the cross section. This can be illustrated, for example, by a circular cross-section (fixed shape): the circumferential length of the circle being π D and its area being 1/4 π D²(D is the diameter of the circle). That is, the decrease in D only linearly decreases the circumferential length, but quadratically decreases the area thereof. It is also possible to reduce only the area while still maintaining its circumferential length unchanged. If, for example, the shape of the circle is also fixed, there is a certain minimum area. By using the fourier series expansion mentioned below, it is possible to perform advanced mathematical calculations in which the shape is a parameter. The cross-section of the pressurizing chamber and/or the piston can have any shape, which can be determined by at least one curve, which is closed and can be substantially determined by two unique modulus parameterization fourier series expansions. One of each coordinate function is:

in the formula

<math> <mrow> <msub> <mi>c</mi> <mi>p</mi> </msub> <mo>=</mo> <mfrac> <mn>2</mn> <mi>π</mi> </mfrac> <msubsup> <mo>&Integral;</mo> <mn>0</mn> <mi>π</mi> </msubsup> <mi>f</mi> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mi>cos</mi> <mrow> <mo>(</mo> <mi>px</mi> <mo>)</mo> </mrow> <mi>dx</mi> </mrow> </math>

<math> <mrow> <msub> <mi>d</mi> <mi>p</mi> </msub> <mo>=</mo> <mfrac> <mn>2</mn> <mi>π</mi> </mfrac> <msubsup> <mo>&Integral;</mo> <mn>0</mn> <mi>π</mi> </msubsup> <mi>f</mi> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mi>sin</mi> <mrow> <mo>(</mo> <mi>px</mi> <mo>)</mo> </mrow> <mi>dx</mi> </mrow> </math>

0≤x≤2π，x∈R

p≥0，p∈N

c_pCos weighted average of (f) (x),

cos weighted average of dp ═ f (x)

p-an order of magnitude representing trigonometric accuracy

Fig. 15A, 15E show examples of the curves by using a set of different parameters of the following equations. In these examples, only two parameters are used. If more parameters are used, optimization curves can be found, and the curves can be adapted to other important requirements, such as requirements on transition curves of the curves; the transition curve has a certain maximum radius and/or a maximum tension, for example at the sealing portion, such that the tension at a given pressure of the sealing portion does not exceed this maximum. As an example: fig. 15F shows optimized convex and non-convex curves that can be applied to various possible deformations under the constraint that the interface line length is fixed and its mathematical curvature is minimal. By using the starting area and starting interface length, the minimum curvature for a particular desired nominal area can be calculated.

The piston, shown in longitudinal section in the cavity, is drawn mainly in the case where the interface curve of its cross section is a circle. That is to say: in the case where the cavity has non-circular cross-sections such as those shown in fig. 15A, 15E, 15F, the shape of the piston within this longitudinal section is different.

According to this formula, a fully closed curve, such as a C-curve, can be drawn (see PCT/DK97/00223, FIG. 1A). One feature of these curves is: when a line is drawn from a mathematical pole located in the plane of the cross-section, this line intersects the curve at least once, the curves being symmetrical about a line in the plane of the cross-section, and the curves can also be generated using the following single fourier series expansion. A piston or a chamber is easier to produce when the curve of the cross-section is symmetrical with respect to a line lying in the plane of the cross-section and passing through the mathematical pole. Such a conventional curve can be approximately determined with a single fourier series expansion:

in the formula

0≤x≤2π，x∈R

p≥0，p∈N

Weighted average of Cp ═ f (x)

p-an order of magnitude representing trigonometric accuracy

When a straight line is drawn from the mathematical pole, the straight line always intersects the curve only once.

The specially formed portion of the cavity and/or piston cross-section can be determined approximately by the following formula:

in the formula

f (x) = r_{0} + a . \sqrt[2 m]{\sin^{2} (\frac{n}{2}) x}

<math> <mrow> <msub> <mi>c</mi> <mi>p</mi> </msub> <mo>=</mo> <mfrac> <mn>6</mn> <mi>π</mi> </mfrac> <msubsup> <mo>&Integral;</mo> <mn>0</mn> <mfrac> <mi>π</mi> <mn>3</mn> </mfrac> </msubsup> <mi>f</mi> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mi>cos</mi> <mrow> <mo>(</mo> <mn>3</mn> <mi>px</mi> <mo>)</mo> </mrow> <mi>dx</mi> </mrow> </math>

0≤x≤2π，x∈R

p≥0，p∈N

Weighted average of Cp ═ f (x)

p-an order of magnitude representing trigonometric accuracy

Also here this cross section in a polar system is approximately expressed by the following formula:

in the formula

r₀≥0，

a≥0，

m≥0，m∈R，

n≥0，n∈R，

0≤≤2π，

And in the formula

r-the limit of the "lobe" in the circular section of the drive pin,

r₀the radius of the circular cross-section around the drive pin,

a is a scaling factor for the "flap" length,

r_max＝r₀+a，

m is a parameter for determining the width of the "flap",

n is a parameter for determining the number of "lobes",

the angle which defines the curve range

The inlet is placed near the end of the stroke due to the nature of the sealing portion of the piston means.

These particular cavities can be produced by injection moulding, for example also by the so-called superplastic forming method, in which aluminium plates are heated and then pressed fully into the tool cavity with air pressure, or also by tool movement.

Fig. 15A shows a series of cross-sections of a cavity, in which the area decreases in steps while the circumferential length remains constant, these being determined by one of two unique modulus parameterized fourier series expansions, each coordinate function. At the top left is a cross section, which is the first cross section in the series. The set of parameters used is shown at the bottom of the figure. The series shows the area of reduced cross-section. The figures show the reduced cross-sectional areas of different shapes in bold, with one of the upper left corners being the starting area dimension.

Fig. 15B shows a longitudinal cross-section of the cavity 162, the cross-sectional area of which varies by maintaining a circumferential length along the central axis. And a piston 163. The cavity has portions of

wall portions

155, 156, 157, 158 that are of different cross-sectional areas in cross-section.

Transitions

159, 160, 161 are between the wall portions. G-G, H-H and I-I are shown. The section G-G has a circular cross-section, while the section H-H152 has an area of about 90-70% of the area of the section G-G.

FIG. 15C shows cross-section H-H152 of FIG. 7G, with comparative section G-G150 indicated by a dashed line. Section H-H has an area of about 90-70% of the area of section G-G. The smooth transition 151 shown is the smallest portion of the cavity, which has a cross-sectional area of about 50% of the G-G cross-section.

FIG. 15D shows the I-I cross-section of FIG. 7G, with the comparative G-G section indicated by a dashed line. Section I-I has about 70% of the area of section G-G. The transition 153 is smooth, showing that it is the smallest part in this cavity.

Fig. 15E shows a series of cross-sections of a cavity in which the area decreases in steps, but the circumferential length remains the same, as determined by one of two unique modulus parameterized fourier series expansions, each coordinate function. At the top left is a cross section, which is the first cross section in the series. The set of parameters used is shown at the bottom of the figure. The series shows the area of reduced cross-section. But by keeping the circumferential length constant it is also possible to increase these areas. The figures show the reduced cross-sectional areas of different shapes in bold, with one of the upper left corners being the starting area dimension. The area to the right of the bottom is about 49% of the size of the starting area.

Fig. 15F shows some curves optimized for a certain fixed-length interface curve. The general formula for the minimum radius of curvature corresponding to the maximum curvature of the graph shown in FIG. 7L is:

the length y is set by

And (4) determining.

Wherein r is the minimum radius of curvature

L is the interface length is constant

A₁Area of initial region A₀Is reduced in value

Taking the case of fig. 3D as an example: area of domain A₀＝π(30)²The interface length L60 pi 188.5 corresponds to the circumferential length and area of the disc of radius 30. The length requirement remains the same, but its area requirement is reduced to a value A₁. The desired final cross-sectional profile should have an area A₁＝π(19/2)²283.5. The convex curve with the smallest possible curvature of the interface is now:

r＝1.54

k＝1/r＝0.65

x＝89.4

the curves in the figure are not drawn to scale and the figure merely shows the basic principle.

The curve can be further optimized by bending the starting line of the change, which improves the sealing of the piston against the wall.

Fig. 16 shows a combination in which the piston includes a resiliently deformable pocket 372 within the cavity 375 and movable between the cylinder wall 374 and the tapered wall 373 (e.g., shown centered about the central axis 370). The piston is suspended from at least one piston rod 371. The cavities 372, 372 'are shown at a second longitudinal position and a first longitudinal position 372 of the cavity 372'.

All the solutions disclosed in this document can be combined with a piston of the type in which the cavity has a cross section of fixed circumferential length dimension as a solution to the problem of clogging.

Fig. 17A shows a convex cavity 400 having walls 401. "s" represents stroke.

FIG. 17B shows a force versus stroke plot for the direction shown in FIG. 17A. The graph shows the optimum variation of the force when the operator operates the pump stroke (with the incoming fluid being located substantially at the first longitudinal position of the chamber and the outgoing fluid being located substantially at the second longitudinal position of the chamber). The curve is tangent to the maximum operating force at approximately the end of the pump stroke.

Fig. 18A shows an example of a movable power supply unit 500. The movement shown is through the parachute-shaped members 501 and through the wheels 502.

Fig. 18B shows a removable power unit 500 comprising a top set of solar cells 503, and a motor 504. In addition, there is a water pump 505, a compressor 506, and a control unit 507.

Claims

1. A piston-chamber combination comprising an elongate chamber (162, 186, 231) bounded by an inner chamber wall (156, 185, 238), and comprising a piston arranged in said chamber to be sealingly movable relative to said chamber at least between first and second longitudinal positions of said chamber,

the cross-section of the cavity having different cross-sectional areas at first and second longitudinal positions of the cavity and at least substantially continuously different cross-sectional areas and circumferential lengths at intermediate longitudinal positions between the first and second longitudinal positions of the cavity, and the cross-sectional area at the first longitudinal position being greater than the cross-sectional area at the second longitudinal position,

said piston including a receptacle (208, 208 ', 217, 217 ', 228, 228 ', 258, 258 ', 450, 450 ') which is resiliently deformable to provide different cross-sectional areas and circumferential lengths of the piston to accommodate different cross-sectional areas and different circumferential lengths of said chamber during relative movement of the piston from said second longitudinal position through said intermediate longitudinal position to said first longitudinal position of said chamber,

wherein,

in the absence of pressure and deformation, the piston is dimensioned with a cavity (208, 208 ', 217, 217 ', 228, 228 ', 258, 258 ', 450, 450 '), wherein in said second longitudinal position the circumferential length of the piston is approximately equal to the circumferential length of said cavity (162, 186, 231), the cavity being expandable from the dimensioned dimension transversely to the longitudinal direction of the cavity, thereby expanding the piston from the dimensioned dimension during relative movement of the piston from said second longitudinal position to the first longitudinal position.

2. The combination of claim 1, wherein the cavity (208, 208 ', 217, 217 ', 228, 288 ' 258, 258 ', 450, 450 ') is expandable, said cavity being elastically deformable and expandable for different cross-sectional areas and circumferential lengths of the piston.

3. A combination according to claim 1 or 2, wherein the cross-sectional area of the cavity at the second longitudinal position is between 98% and 5% of the cross-sectional area of the cavity at the first longitudinal position.

4. A combination according to claim 1 or 2, wherein the cross-sectional area of the cavity at the second longitudinal position is between 95% and 15% of the cross-sectional area of the cavity at the first longitudinal position.

5. A combination according to claim 1 or 2, wherein the cross-sectional area of the cavity at the second longitudinal position is 50% of the cross-sectional area of the cavity at the first longitudinal position.

6. A combination according to any of claims 1 to 5, wherein the cavity (208, 208 ', 217, 217 ', 228, 228 ', 258, 258 ', 450, 450 ') comprises a deformable material (205, 206).

7. A combination according to claim 6, wherein the deformable material (205, 206) is a fluid or a fluid mixture such as water, steam and/or gas or a foam material.

8. A combination according to any of claims 1 to 6, wherein the deformable material comprises a resiliently operated device, such as a spring.

9. A combination according to claim 6 or 7, wherein, in a cross-section through the longitudinal direction, the receptacle has a first shape when arranged at a first longitudinal position of the cavity (162, 186, 231) and which is different from a second shape when arranged at a second longitudinal position of said cavity.

10. A combination according to claim 9, wherein at least part of the deformable material (206) is compressible and wherein the area of the first shape is larger than the area of the second shape.

11. A combination according to claim 9, wherein the deformable material (206) is at least substantially incompressible.

12. A combination according to claim 6 or 7, wherein the chamber is inflatable to a predetermined pressure.

13. A combination according to claim 12, wherein the pressure is maintained constant during the stroke.

14. A combination according to any of claims 6 to 13, wherein the piston (208, 208 ', 217, 217 ', 228, 228 ', 258, 258 ', 450, 450 ') comprises an enclosed space (210, 243) communicating with the deformable volume, said enclosed space (210, 243) having a variable volume.

15. A combination according to claim 14, wherein the volume is adjustable.

16. A combination according to claim 14, wherein the first enclosed space (210) comprises a spring-biased pressure regulating piston (126).

17. A combination according to any of claims 14 to 16, further comprising means (126, 195, 246, 248, 249, 273, 274) for defining the volume of the first enclosed space (210) such that the pressure of the fluid in the first enclosed space (210) is related to the pressure in the second enclosed space (243).

18. A combination according to claim 17, wherein the defining means (126, 194, 195, 246, 248, 249, 273, 274) defines the pressure in the first enclosed space (210) during the stroke.

19. A combination according to claim 17, wherein the defining means (126, 195, 246, 248, 249, 273, 274) define the pressure in the first enclosed space (210) to be at least substantially constant during the stroke.

20. A combination according to claim 16, wherein the spring biased pressure regulating piston (126) is a one way valve (242) through which fluid from an external pressure source may flow into the first enclosed space (210).

21. A combination according to claim 20, wherein fluid from an external pressure source can be passed from the external pressure source through an inflation valve, preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (241), into the second enclosed space (243).

22. The combination of claim 1, wherein the piston (248) is in communication with at least one valve (260).

23. A combination according to claim 22, wherein the piston includes a pressure source.

24. A combination according to claim 22, wherein the valve is an inflation valve, preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (260).

25. A combination according to claim 22, wherein the valve is a one-way valve.

26. A combination according to claim 1, wherein the bottom (262) of the chamber (162, 186, 231) is connected to at least one valve (263, 269).

27. A combination according to claim 26, wherein the discharge valve is an inflation valve, preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (263), said core pin moving towards the chamber (162, 186, 231) when closing the valve.

28. A combination according to claim 24 or 26, wherein the core pin (245) of the valve (260, 263) is connected to a valve actuator for opening or closing the valve.

29. A combination according to claim 28, wherein the actuator is a valve actuator for operation with a valve provided with a spring force operated spool pin, comprising:

a housing connected to a source of pressure medium;

a housing within which:

a connecting portion for receiving a valve to be actuated,

a cylinder surrounded by a cylindrical wall having a predetermined cylindrical wall diameter and having a first cylinder end and a second cylinder end remote from the connecting portion than said first cylinder end,

a piston movably disposed in the cylinder and fixedly connected to an actuating pin for engagement with a spring force operated spool pin of a valve received in the connecting portion, an

A guide channel for guiding pressure medium from the cylinder end to the connecting portion when the piston is moved to a first piston position at a first predetermined distance from said first cylinder end and for preventing the cylinder end from being moved when the piston is moved to a second piston position at a second predetermined distance from the first cylinder end

And a connection portion, and said second distance is larger than said first distance,

wherein,

a guide channel is arranged in the cylinder and provided with a wall portion opening into the cylinder at a predetermined cylinder wall diameter, and

a piston comprises a piston ring with a sealing lip which sealingly cooperates with the cylinder wall portion, preventing pressure medium from being led from the second cylinder end into the passage in the second piston position, thereby opening the passage to the second cylinder end in the first piston position.

30. A combination according to claim 28, wherein the actuator is a valve actuator for operation with a valve provided with a spring force operated spool pin, comprising:

a housing connected to a source of pressure medium;

a housing within the housing;

a connecting portion for receiving a valve to be actuated,

a cylinder circumferentially surrounded by a cylindrical wall having a predetermined cylindrical wall diameter, having a first cylinder end and a second cylinder end remote from the connection portion than said first cylinder end, and said second cylinder end being connected to a housing for receiving pressure medium from said pressure source,

A guide channel between said second cylinder end and said connection portion for guiding pressure medium from said second cylinder end to the connection portion when the piston is moved to a first piston position at a first predetermined distance from said first cylinder end and for preventing said second cylinder end when the piston is moved to a second piston position at a second predetermined distance from the first cylinder end

wherein,

a guide passage is arranged in the cylinder and provided with a passage portion which opens into the cylinder at a cylinder wall portion having the predetermined cylinder wall diameter, and

a piston comprises a piston ring with a sealing lip, which sealingly engages the cylinder wall part, and the sealing lip of the piston ring is located between the channel part and the second cylinder end in the second piston position, so that the leading of pressure medium from the second cylinder end into the channel in the second piston position is prevented, and the sealing lip of the piston ring is located between the channel part and the first cylinder end in the first piston position, so that the channel to the second cylinder end in the first piston position is opened.

31. The combination of claim 28 wherein the actuator is an actuator valve for a chamber piston pressure management system which feeds compressed air into the interior of the chamber piston, said valve comprising a valve body having a cylindrical central passage opening into said compressed fluid and into the interior of said chamber piston,

a check valve spring-loaded in the central passage blocks the central passage when the check valve is closed and allows flow when the check valve is open.

A spring slidably loads a piston above a check valve in the passage, the piston sliding from a closed position to an open position toward the check valve when the compressed fluid is supplied and closing again when the compressed fluid is removed. The piston engages the central passage surface with sufficient clearance to allow unrestricted sliding movement, but insufficient access to allow leakage of compressed fluid between the piston and the central passage surface, and a curved rod is carried by the piston and engages the one-way valve to open it when the piston moves to the open position, allowing compressed fluid to pass to the one-way valve and to the interior of the chamber piston.

A fixed plug is located in the central passage between the check valve and the piston through which the knee lever extends, the plug being generally axially spaced from the piston but adjacent the piston in its open position. Said plug having a through hole from atmosphere into the space between said plug and piston at a radial through hole point near said knee lever, such that compressed fluid leaking past said piston during movement will not be compressed between said plug and piston to retard its movement, and,

a circular compression seal around the point of the through hole is compressed when the piston and plug are adjacent so that compressed air leaking past the piston cannot enter the atmosphere when the check valve is opened.

32. The combination of claim 28 wherein the actuator is an actuator valve for a chamber piston pressure management system which feeds compressed fluid to the interior of the chamber piston, said valve comprising a valve body having a cylindrical central passage opening to said compressed fluid and to the interior of said chamber piston,

A spring slidably loads a piston above a check valve in the passage, the piston sliding from a closed position to an open position toward the check valve when the compressed fluid is supplied and closing again when the compressed fluid is removed. The piston engages the central passage surface with sufficient clearance to allow unrestricted sliding movement, but insufficient proximity to allow leakage of compressed fluid between the piston and the central passage surface, when the piston is moved to the open position,

a bell crank is carried by the piston and in combination with the check valve opens it to allow compressed fluid to pass to the check valve and the interior of the chamber piston.

An outer annular disc and an inner annular disc adjacent within the central passage and forming a plug between the check valve and the piston through which the knee lever extends. Said piston being normally axially spaced from said outer disc but adjacent to its open position, said outer disc having a series of apertures radially adjacent said knee opening into a series of recesses in said inner disc and forming through-holes from the atmosphere into the space between said plug and piston so that compressed fluid leaking past said piston when displaced is not compressed between said plug and piston to retard its movement, and,

an annular compression seal surrounding said bore is compressed when said piston and plug are adjacent such that compressed air leaking past said piston is not allowed to enter atmosphere when the one-way valve is opened.

33. The combination of claim 28 wherein an actuator pin for connection to the inflation valve comprises

A housing connected to a source of compression;

in the housing

A connection bore having a central axis and an inner diameter corresponding to an outer diameter of an inflation valve connected to the actuating pin, and;

a cylinder and means for generating a liquid medium between the cylinder and a compression source,

wherein the actuating pin

Arranging a center spring force of a core pin engaged to operate the inflation valve;

arranged on an extension line of a connecting hole coaxial with the central shaft in the shell;

comprises a piston part with a piston, wherein the piston is arranged in a cylinder and can move at a first piston position and a second piston position;

the actuator pin includes a passage;

said piston portion including a first end and a second end, wherein the piston is located at the first end and said passageway has an opening at the first end;

a valve portion movable in the channel, actuated by a force acting on a surface of the valve portion, in a first valve position and a second valve position, wherein the first valve position opens the opening and the second valve position closes the opening, and;

the piston portion top end forms a cover for the valve with a valve seat.

34. The combination of claim 28 wherein the valve actuator is an actuator pin for connection to the inflation valve, comprising:

a housing

In the shell, a connecting hole is connected with an inflation valve, and the connecting hole is provided with a central shaft and an external opening;

a fixing means for fixing the inflation valve when connected in the connecting hole, and;

an actuating pin, axially disposed with the connecting hole, for depressing a core pin of the inflation valve operated by the central spring force;

a cylinder having a cylinder wall providing a pressure port, the pressure port being connected to a pressure source, wherein;

the actuating pin is movable relative to the fixture between a proximal pin position and a distal pin position to depress the core pin of the inflation valve at a position depressing the distal pin thereof and disengage the core pin of the inflation valve at a position proximal to the proximal pin thereof when the inflation valve is secured by the fixture;

an actuating pin is connected to the piston and the piston is slidably disposed within the cylinder, the piston moving between the proximal pin and the distal pin relative to the position of the proximal pin and the position of the distal pin;

a piston disposed in the cylinder between the pressure port and the connecting bore, the piston being driven by pressure supplied by the pressure source to the cylinder at its nearest piston position and at its distal piston position, and;

the flow regulating device is used for selectively interrupting and releasing the flow path between the pressure source and the connecting hole according to the position of the piston and is regulated to interrupt the flow path at the nearest piston position and release the flow path at the distal piston position when the charging valve is at least fixed by the fixing device

35. A combination according to claim 22, wherein the piston comprises means for achieving a predetermined pressure level.

36. A combination according to claim 22 or 35, wherein the valve is a release valve.

37. A combination according to claim 35, wherein a spring force operated cover (312, 312') closes the passage (286) above the valve actuator (315) at a pressure above a predetermined pressure value.

38. The combination of claim 35,

a channel is openable or closable, the channel connecting the cavity (186) and the gap (305, 306, 307) between the valve actuator (261) and the core pin (245),

a piston (292) movable between an open position (294) and a closed position (295) of the passage, an

The movement of a piston (292) is controlled by an actuator (363) which is operated in response to pressure measurements in the piston (208, 208 ', 217, 217 ', 228, 228 ', 238, 238 ', 450, 450 ').

39. A combination according to claim 27, wherein a channel (297) is openable or closable, the channel connecting the chamber (186) and the space (305, 306, 307) between the valve actuator (261) and the core pin (245).

40. A combination according to claim 27 or 39, wherein a piston (292) is movable between an open position (294) and a closed position (295) of said passageway.

41. A combination according to claim 40, wherein the piston (292) is operated by an operator controlled pedal (265) which is rotatable about an axis (264) from an unactuated position (277) to an actuated position (277') or vice versa.

42. A combination according to claim 40, wherein the piston (292) is controlled by an actuator (366) which is operated in dependence on pressure measurements in the piston (208, 208 ', 217, 217 ', 228, 228 ', 238, 238 ', 450, 450 ').

43. A combination according to any of claims 14 to 16, further comprising means (321, 322, 323, 324) for defining the volume of the enclosed space (325) during the stroke so that the fluid pressure in the enclosed space (210) is related to the pressure acting on the piston (208, 208').

44. A combination according to any of claims 7 to 19, wherein the foam material or fluid is adapted to provide a pressure in the cavity which is higher than the highest pressure of the surrounding atmosphere during translation of the piston (148, 149) from the second longitudinal position of the cavity (216) to its first longitudinal position or vice versa.

45. The combination of claim 2, wherein the combination comprises a pressure source (701).

46. A combination according to claim 45, wherein the pressure source (701) has a higher pressure level than the chambers (208, 208 ', 217, 217 ', 228, 228 ', 238, 238 ', 450, 450 ').

47. A combination according to claim 45, wherein the pressure source (701) communicates with the chamber (208, 208 ', 217, 217 ', 228, 228 ', 238, 238 ', 450, 450 ') via an exhaust valve (704) and an inlet valve (702).

48. A combination according to claim 47, wherein the venting valve (704) is an inflation valve, preferably a valve with a core pin biased by a spring, such as a Schrader valve, said core pin being moved towards the pressure source (701) when the valve is closed.

49. A combination according to claim 47, wherein the inlet valve (702) is an inflation valve, preferably a valve with a core pin biased by a spring, such as a Schrader valve, said core pin moving towards the cavity (208, 208 ', 217, 217 ', 228, 228 ', 238, 238 ', 450, 450 ') when closing the valve.

50. A combination according to claim 48, characterised in that a channel (297) can be opened or closed, which connects the cavity (708) and the space (305, 306, 307) between the actuator (261) and the core pin (245).

51. A combination according to claim 49, characterised in that a channel (297) can be opened or closed, which connects the cavity (707) and the space (305, 306, 307) between the actuator (261) and the core pin (245).

52. A combination according to claim 50 or 51, wherein the piston (292) is movable between an open position (292') and a closed position (292) of said passage.

53. The combination of claim 48 wherein

A channel (297) which can be opened or closed, connects the chamber (708) and the space (305, 306, 307) between the valve actuator (261) and the core pin (245) via a space (712);

the piston (292) is movable between an open position (292') and a closed position (292) of the passage;

the movement of the piston (292) is controlled by an actuator (722) which is operated in dependence on measurements in the piston (208, 208 ', 217, 217 ', 228, 228 ', 238, 238 ', 450, 450 ') and the pressure source (701).

54. The combination of claim 49 wherein

A channel (297) which can be opened or closed, through the space (710), connects the chamber (707) and the space (305, 306, 307) between the valve actuator (261) and the core pin (245);

the movement of the piston (292) is controlled by an actuator (723) which is operated in accordance with measurements in the piston (208, 208 ', 217, 217 ', 228, 228 ', 238, 238 ', 450, 450 ') and the pressure source (701).

55. A combination according to claims 6 to 19, wherein the chamber wall comprises a resiliently deformable material including the reinforcing structure.

56. The combination of claim 55 wherein the windings of the reinforcement portion have a braid angle that deviates from 54 ° 44'.

57. A combination according to claims 55 to 56, wherein the reinforcing means comprises a fabric reinforcing portion which is capable of expanding when the chamber is moved to the first longitudinal position and of contracting when moved to the second longitudinal position.

58. The piston of claim 57 wherein the piston is manufactured by a manufacturing system having a plurality of vulcanization chambers.

59. A combination according to claim 55 or 56, wherein the reinforcing means comprises fibres which are capable of expanding when the chamber is moved to the first longitudinal position and of contracting when the chamber is moved to the second longitudinal position.

60. A combination according to claim 59, wherein the piston is manufactured by a manufacturing system having a plurality of vulcanization chambers (801), and the fibers (802) are positioned in the bores (801) of the cap 800 by rotating the fibers 802 and the cap 800 at different speeds while the fibers 802 are pushed into the interior of the cap 800.

61. A combination according to claim 59, wherein the fibres are arranged according to a lattice effect.

62. A combination according to claim 55, wherein the reinforcing structure comprises a flexible material disposed in the cavity, said flexible material comprising a plurality of at least substantially resilient support members rotatably secured to a common member, and the common member being connected to the skin of the cavity.

63. The combination of claim 62, wherein the support member and/or the common member are inflatable.

64. A combination according to claim 1 or 2, wherein the pressure on the chamber wall is applied by spring force operated means.

65. A combination according to claim 1 or claim 2, wherein the piston includes a reinforcement located outside the chamber.

66. A combination according to claim 1 or 2, wherein the cavities 372, 372' move in the cylinder around a conical wall 372.

67. A combination according to claim 1 or 2, wherein the cavity is convex and the operating force reaches a set maximum force during the stroke.

68. A combination according to any of the preceding claims or a combination of a piston comprising a housing, the combination having a flexible wall, having a manufactured dimension which is similar to the length of the first longitudinal position of the chamber, having a reinforcement which allows a contraction with high friction, characterized in that the different cross-sections have different cross-sectional shapes, the change in cross-sectional shape being at least substantially continuous at the first and second longitudinal positions of the chamber (162), characterized in that the piston (163) is designed to adjust itself and the sealing means to different cross-sectional shapes.

69. A combination according to claim 68, wherein the cavity (162) at the first longitudinal position is at least substantially circular, and wherein the shape of the cross-section of the cavity (162) at the second longitudinal position comprises two or more at least substantially elongated portions, such as ellipses, having a first dimension which is at least 2 times, such as 3 times, in particular at least 4 times, the dimension at an angle to the first dimension.

70. A combination according to claim 68 or 69, characterized in that the cavity (162) at the first longitudinal position is at least substantially circular, and in that the shape of the cross-section of the cavity (162) at the second longitudinal position comprises two or more at least substantially elongated portions, such as elongated portions of an ear lobe.

71. A combination according to claim 68 or 69, characterized in that the first circumferential extent of the shape of the cross-section of the cylinder (162) at the first longitudinal position is 80-120%, such as 85-115%, in particular 90-110%, such as 95-105%, in particular 98-102% of the second circumferential extent of the shape of the cross-section of the cavity (162) at the second longitudinal position.

72. The method of claim 70 wherein the first and second circumferential lengths are at least substantially the same.

73. A piston-chamber combination comprising an elongate chamber (231) bounded by an inner chamber wall and comprising a piston disposed in the chamber for sealed movement therein,

a piston (230) is movable at least in the chamber (231) from a second longitudinal position thereof to a first longitudinal position,

a chamber (231) includes an elastically deformable inner wall (238) along at least part of the chamber wall length between the first and second longitudinal positions,

a first cross-sectional area of the chamber (231) at a first longitudinal position of the piston (230) when the piston is at that position, and the first cross-sectional area being greater than a second cross-sectional area of the chamber (231) at a second longitudinal position of the piston (230), the change in cross-section of the chamber (231) between the first and second longitudinal positions being at least substantially continuous as the piston moves between the first and second longitudinal positions,

the piston comprises an elastically expandable cavity, the pistons having a geometry mutually adjusted during the piston stroke so as to be continuously closed, the piston having its dimensions when in the second longitudinal position of the cavity.

74. A combination according to claim 73, wherein the piston (230) is made of an at least substantially incompressible material.

75. A combination according to claim 73 or 74, wherein the piston (230) has, in a cross-section along the longitudinal axis, a cross-section which tapers in a direction from the first longitudinal position of the chamber (231) to the cross-section of its second position.

76. A combination according to claim 47, wherein the angle (i) between the wall (238) and the central axis (236) of the cylinder (231) is at least smaller than the angle (6) between the wall of the tapering portion of the piston (230) and the central axis (236) of the chamber (231).

77. The combination of any of claims 73 to 76, wherein the cavity (231) comprises:

an outer support structure (234) enclosing an inner wall (238), and

a fluid (232, 233) held in a space defined by the outer support structure (234) and the inner wall (238).

78. A combination according to claim 77, wherein the space defined by the outer support structure (234) and the inner wall (238) is inflatable.

79. A combination according to claim 73, wherein the piston (450') comprises an elastically deformable cavity comprising a deformable material and designed according to claims 7 to 17.

80. A pump for pumping a fluid, comprising:

a combination according to any one of the preceding claims;

means for connecting the piston from a position outside the chamber;

a fluid inlet having a valve means and connected to the chamber; and

a fluid discharge port connected to the chamber.

81. A pump according to claim 80, wherein the coupling means has an outer position in which the piston is in the first longitudinal position in the chamber; there is also an inner position in which the piston is in the second longitudinal position in the chamber.

82. A pump according to claim 80, wherein the connecting means has an outer position in which the piston is in the second longitudinal position in the chamber; there is also an inner position in which the piston is in the first longitudinal position in the chamber.

83. A shock absorber having:

a combination according to any one of claims 1 to 80;

means for connection to the piston from outside the chamber, the connection means having an outer position in which the piston is in its first longitudinal position; there is also an inner position where the piston is in its second longitudinal position.

84. A shock absorber according to claim 83, further comprising a fluid inlet associated with the chamber and having a valve means.

85. A shock absorber according to claim 83 or 84, further comprising a fluid outlet port associated with the chamber and having a valve means.

86. A shock absorber according to any one of claims 83 to 85, wherein the chamber and the piston define at least a cavity having a substantially fluid tight seal, the fluid being compressed as the piston moves from the first longitudinal position to the second longitudinal position.

87. A shock absorber according to any one of claims 83 to 86, further comprising means for biasing the piston towards its first longitudinal position.

88. An actuator having:

a combination according to any one of claims 1 to 80;

means for connecting to the piston from a position outside the chamber;

89. The actuator of claim 88 further comprising a fluid inlet connected to the chamber and having a valve means.

90. An actuator as claimed in claim 88 or 89 further comprising a fluid discharge port associated with the chamber and having a valve means.

91. An actuator as claimed in any of claims 88 to 90 further comprising means to bias the piston towards the first or second longitudinal position.

92. An actuator as claimed in any of claims 88 to 91 wherein the introducing means comprises means for introducing pressurised fluid into the chamber.

93. An actuator as claimed in any of claims 88 to 91 wherein the introducing means is for introducing a combustible fluid such as gasoil or fuel into the chamber; the actuator also has means for combusting the combustible fluid.

94. An actuator as claimed in any of claims 88 to 91 wherein the pouring means is arranged to direct the inflation fluid into the chamber, and wherein the actuator further comprises means for inflating the inflation fluid.

95. An actuator as claimed in any of claims 88 to 91 wherein there is a crank for translating movement of the piston into a crank rotation.

96. An engine comprising the combination of any one of claims 1-95.

97. A power unit comprising:

the combination of any one of claims 1-96;

a power source and a power unit.

98. The power unit as claimed in claim 97, wherein the unit is movable.