GB2516272A - Piston - Google Patents

Abstract

An activation mechanism 3 to transmit fluid distributed pressure in machines destined to move mobile, sliding couplings such as those seen in hydraulic pistons is provided. A hermetically sealed container 1, which permits the movement of a work piston 2, includes a helical tube and threaded cup 9. The container 1 encloses the activation mechanism 3. The activation mechanism 3 includes a backstop 4, a crank 5, a threaded cylinder 6 and a helical piston 7. The helical piston 7 and helical tube 8 have the same pitch, as does each of the threaded piston 6 and threaded cup 9, and allows the helical piston 7 to advance along the helical tube 8 as it rotates.

Description

"PISTON"

1. FIELD OF THE INVENTION:

The invention presents an activation mechanism to transmit fluid distributed pressure in machines destined to move mobile, sliding couplings such as those seen in hydraulic pistons.

An important application of the invention is moving loads by way of activating emboli that, due to its particular architecture, favors savings in the physical space and dimensioning of machines. The designed device might be equally conceived for the improved performance of internal-combustion engines and hydraulic hoists.

2. BACKGROUND OF THE INVENTION:

A simple, hydraulic hoist is a machine that associates a pair of emboli presenting different transversal section surfaces. Considering Pascal's principal for distributing fluid enclosed in a determined volume, we know that the internal pressure in the compartment of a machine propagates in all the directions. To elevate a load to certain distance "h", it is necessary that the surface of the piston, once activated, travel this distance, thus dislocating a volume = S.h, in which "S" expresses the magnitude of the area of the surface of the piston activated. To provoke the movement "V", we can activate another entry piston, the surface of the transversal scction of which is s. To dislocate this scction to a distance "H", wc have to dislocate the same volume V = s.H in both pistons, that of entry and that of exit, in which hydraulic fluid is confined in a hermetically sealed compartment. The force "f' applied to the entry piston necessary to lift a burdcn "F" is reduced in the theoretical proportion f.S = F.s.

Although this reprcsents a huge operational advantage, we note that thc entry embolus must travel a trajectory H proportionally greater than h, equivalent to the mechanical advantage obtained from the relationship between the forces. In summary: the relationship of entry/exit power between the two emboli is directly proportional to the areas of their transversal sections and inversely proportional to the distances traveled by the action of the forces that act on them. We can highlight as the primary problem in these systems that the piston activating mainly, and the work piston, both require exaggerated dimensioning, which negatively affects the design of machines.

3. SOLUTIONS OF THE INVENTION: We describe a solution for the design of pistons that guarantees certain facility for the operation of machines. Better distribution of forces between the elements that make up the activating mechanism of the machine as to economize physical space in the dimensioning of the machine itself The object of this invention is to activate hydraulic emboli effectively while economizing spacc.

The object of this invention is to promote a machine that supports heavy loads on the exit embolus.

The object of this invention is to inspire innovations in motors, be they in the entry pistons or in the exit pistons of machines.

A further object of the invention is to foresee shorter longitudinal displacement of emboli occurring in a space inferior to that of the movement of its surface given by a normal transversal section.

The objectives above highlight some relevant aspects of the invention. Other advantages may arise from modifications and improvements inspired by this content without, nevertheless, infringing upon its scope.

4. SUMMARY OF THE INVENTION:

It deals with an assembly made up of a hermetically sealed container 1 that permits the movement of a work piston 2 with a surface of normal transversal section S. The activation 3 is made up of a backstop 4, a crank 5, a threaded cylinder 6, and a helical piston 7. Inside container 1 is housed an empty helical tube 8 in such a way that a fluid may occupy its interior space. Helical tube 8 is mounted solidly onto container 1 around a threaded cup 9 that constitutes the frontal part in the design of container 1. It is important to point out that threaded cup 9 is threaded on the inside (about its external surface with respect to container 1) and that threaded cylinder 6 is threaded on the outside, both manufactured in such a way that their thread patterns matches in paired perfectly. Similarly, it is important to point out that both helical piston 7 and helical tube 8 have the same characteristics of advancing step and diametrical dimensioning in such a way that helical piston 7 is able to move circularly inside helical tube 8. Finally, it is important to point out that the threads of threaded cylinder 6 are compatible with the advancing step of helical piston 7 in such a way that the advancing should occur, both in threaded cup 9 and in helical tube 8, in conjunction with activation 3 such that conflicts are avoided.

It is evident that, if work piston 2 has a circular base, the area of its transversal section is S = ir.R2 in which R is the radius of the cylinder. It is equally obvious that, if helical piston 7 has a circular area of its transversal section, s = m.r2 in which r is the radius of the transversal section of the helix. Movement displacement h of work piston 2 is obtained by direct observation. Moreover, displacement H of the area of the section of helical piston 7 is obtained as being Fl > n.2m.p (later, we will see the precise formulation), in which p is the radius of thc helix turn and n is the number of turns it contains.

With this mechanism, we can make H vary from zero up to a reasonably higher value, confining its moving in a significantly smaller physical space. The relationship between theoretical forces of action/reaction expected for the machine is s/S. The linear displacement of helical piston 7 in relation to container 1 will be its length "C", while the frill displacement of activation will be H, various times greater than "C".

The invention is presented graphically by way of the designs that follow.

5. BRIEF DESCRIPTION OF THE DRAWINGS:

Fig. 1-A The flattened view to calculate the course of trajectory "Hi" of the helical piston Fig. 1-B The flattened view to calculate the course of the trajectory "H'1" of the threaded cylinder Fig. 2 Activation: crank, backstop, threaded cylinder, helical piston Fig. 3 Container, work piston, threaded cup, and helical tube Fig. 4 Assembly of a hydraulic machine with a helical piston in its initial condition Fig. 5 Assembly ofa hydraulic machine with a helical piston in its final condition Fig.6 Assembly of a hydraulic machine with a helical piston in its final condition, wherein activation is made by secondary actuator equipped with worm screw and worm wheel Fig.7 Details of secondary actuator

6. DESCRIPTION OF THE EXEMPLARY EMBODIMENTS:

Helical piston 7 is machined or molded starting from metal, resin, Kevlar, plastic, or some other material with characteristics of great hardness and low ductility. The transversal section of this piston should have a surface designated by "s" preferably having the format with a circumference of radius "r". Fig. 1-A shows the conditions under which the helix will have a total length "C" parallel to its longitudinal axis and will have a number "n" of turns, not necessarily an integer number. Thus, a length "a1" relative to a single him longitudinal advance displacement might be calculated by the expression: a1 = C/n The average radius of the cylinder equal to that of the helix around which it is revolved will receive the denomination "p". If we revolve the helix around its longitudinal axis with its perimeter tangent to a plane without permitting slipping, after one revolution, the horizontal distance traveled by a point distinguished in the center of its transversal section will be: L2irp Simultaneously, such point will move vertical a1 because the helix has a lead angle of longitudinal advance "1". Thus, it is evident that: tan(X) = apL or equivalent to: A = atan [(C/n)!(2itp)]. The preceding equation gives all the information necessary to fabricate the helix by way of its average primitive line once we determine the "thickness" of its transversal profile, in the ease of the circular example, by way of the determining "r". The area of the section for example the given will be calculated by the formula s = In Fig. 1-A, we can also see that the distance H1 expresses the hypotenuse of a triangle the shorter sides of which are a1 and L. Thus, we calculate Eli = J[(al)2 + (L)21. Alternatively, we can calculate the hypotenuse by way of the formulas Hi = a1.! sin(X) or H1= L./ cos(X).

It is clear that the total path Hn or simply "H" will be Hn = H = n.H1.

The volume occupied by helical piston 7 will be V = s.H that, in the case of a circular section, will be V = m.r2.n. [(ai)2 + (L)21.

Fig. 1-B presents a threaded cylinder 6 centered on a backstop 4 also preferentially with a cylindrical-circular format. A crank 5 might be coupled into the exterior wall of backstop 4 to facilitate manipulation if a user wants to activate the system with greater practicality.

Alternatively, backstop 4 may present a toothed pattern on its cylindrical periphery, constituting in and of itself a gear to activate a reduction motor. It is important to note, as shown by Fig. 2, that helical piston 7 will be rigidly soldered onto backstop 4 so that both the surface of threaded cylinder 6 and that of helical piston 7 have longitudinal axes of revolution in common and coincident. It is important to point out that helical piston 7 does not touch the walls of threaded cylinder 6, being only parallel to it in the set configuration. We will call complete mounted set, activation 3.

The function of threaded cylinder 6 is to offer an advance displacement for activation 3, which is identical to the advance foreseen for helical piston 7, freeing this last from undesirable radial tensions.

Thus, we define the advance of one turn of the screw in threaded cylinder 6 as being a1 with a value identical to the longitudinal advance for one turn made in helical piston 7 (Fig. 1). We verify that threaded cylinder 6 has a radius p less than p assuming that, in our assembly, the helix was fixed on the outside of the cylinder. The peripheral movement in one revolution of p supplies us with U = lip. The normal lead angle of advance of the threaded cylinder 6 will be A? = atan(ai/L'), which will guarantee compatibility so that activation 3 as a whole acquires the same longitudinal lead advance with respect to the machine.

Fig. 3 shows a container 1 that will receive the hydraulic fluid beyond housing the accessory components. It is vital that container I be a hermetically sealed, reinforced box into which the hydraulic fluid responsible for distributing internal pressure throughout the chamber will be injected. The upper part has a cavity in which work piston 2 will travel in translation. The front part has a closed, cylindrical indentation that constitutes threaded cup 9. Threaded cup 9 admits a helical tube rigidly soldered to a wall inside the container 1. On its outside wall, that is to say the wall which is in contact with the exterior of container 1, the threaded cup 9 is threaded in such a way that it admits the screw of threaded cylinder 6 of activation 3, compatibly, fitting perfectly without interferences. Lid 10 was designed foreseeing some difficulty in installing and soldering helical tube 8 as well as to facilitate introducing work piston 2 during the assembly. It is important to note that helical tube 8 is empty hollowed.

One of its extremities enters the compartment of container 1, but its other end reaches the outside environment. Helical tube 8 is almost totally inserted into the inside cavities of container 1 except for its end, which has hermetically sealed outside walls rigidly soldered to the front part of container I. Fig. 3 refers to describe, mainly shown in the right lateral view.

In Fig. 4, we can better visualize that activation 3, being aligned with threaded cup 9, will also be adapted to the components of threaded cylinder 6 simultaneously with helical piston 7 that will enter helical tube 8. When we turn backstop 4, we will be promoting the entry of the activation 3 into container I, while helical piston 7 travels the channel inside helical tube 8, dislocating the volume of fluid foreseen for the operation. It is evident that the volume of hydraulic fluid held by the tube should be equivalent to the volume calculated to be occupied by helical piston 7. Thus, we compute the volume dislocated by work piston 2, multiplying the linear displacement by the area of the surface of its transversal section S. Considering that, in our example, we adopt a cylindrical profile for work piston 2, we have its radius in transversal section "R". The surface of the section is S = m.R2, and the displacement of the piston will be referred to as "h". Thus, we find V = h. m.R2. This is the volume to be equalized with the first equation related in the description of helical piston 7. The dimensional equation for the machine will be: h. mR2 = V = m.r2.n. fI[(ai)2 + (L)2]. If the sections in the pistons were square, we would have an analogous equation in which mR2 and m.r2 would be substituted by B2 and b2 in which "B" and "b" would be the sides of two squared polygons. L and a1 would have their values preserved.

Fig. 5 illustrates the condition under which activation 3 is fully active and under which work piston 2 is found in its position of maximum displacement "h".

The primitive force for the activation arises from the ratio f Q. s/S, which is responsible for the action of the sectional areas in transverse, in which Q is a load imposed on work piston 2.

Nevertheless, the torque necessary to apply such force is minimized by the revolution foreseen in the activation 3.

The final, applicable, theoretical force will be: T = fip!R', in which R' is thc distancc of crank 5 from thc ccntcr of backstop 4.

Fig.6 shows a variant fit of vcrtical lifter. Thc activation 3 is replaccdby a sccondary actuator 15, wherein the backstop 4 undergoes a keyed or hex hole. The backstop 4 is programmed to go along a rotary shaft 11 in linear translation. The rotary shaft 11 rotates around a hollowed shaft 12 fixed on the chassis, whose center communicates the two chambers of the oil container 1. Noting that the displacement of the full course of activation 3 is 2.AC, we built the rccipicnt with this provision. Thc top portion of thc rotaiy shaft 11 undcrgocs coupling to a crown 13 that ultimately will be driven by worm pinion 14 with thlcrum in the chassis, which communicatc to a crank or undergoes motorized. Figure 7 shows details of sccondary actuator 15 in front and sidc vicws. Notice that the rectilinear movcment along of actuator 3, which combined with the rotation of the rotary shaft 11 itself will present the combined motion properly programmed to extract and into the helicoid piston 7 inside helical tube 8.

Pinion and crown gears will combine mechanical plus hydraulic power to the machine, allowing for the load to be released with no turn backs.

7. CONCLUSION:

Although the invention has been described in one of its primary variants, it should be understood that modifications might be redesigned in terms of the manner, number, construction, and arrangements in parts of the machine as long as, nevertheless, the spirit of protection of the scope of this invention remains assured.

That which is required by this invention comes in the form of the following appended claims.

Claims (3)

1. CLAIMS: I. An activating mechanism for hydraulic or pneumatic machines comprising an equipped recipient with a container capable of housing the contents of a hydraulic or pneumatic fluid, said container provided with an embolus with an exit piston capable of performing work, hereinafter refened to as the work piston, comprising an helical entry activation capable of dislocating the internal fluid existing in said container wherein the displacement of activation is caused by means of a screwing apparatus.
2. 2. An activating mechanism according to claim I wherein i) said activation couples dynamically to said container so that clamping it; said activation is made up of a threaded cylinder and an helical piston; said threaded cylinder is placed within inside the helical piston and both are centered; one extremity of said helical piston is rigidly soldered onto a backstop, said backstop serving as a soldered topped base for the threaded cylinder; threaded cylinder and helical piston are provided with identical lead angle profiles so that when the activation turns inwards, it simultaneously advances the threaded cylinder and the helical piston with respect to the machine; said helical piston presents a normal transversal section of areas; ii) said container is capable of admitting a work piston with a normal transversal section of an area S; said container has a hermetically scaled, cylindrical cavity in the form of a cup that conforms to a threaded cup in the wall that makes contact with the outside environmcnt; said threaded cup is able to receive the introduction by threading of the screw-die of said threaded cylinder existing in the activation; a helical tube is rigidly soldered into the cylindrical cup wall inside the container, which conforms to the threaded cup existing in the outside; said helical tube is configured to admit the introduction of said helical piston in a perfect intermeshing; iii) the balance of forces applied to said helical piston screw on the resistive load housed on said work piston is s!S; the balance of linear displacement between said work piston and said helical piston with reference to the machine is hI(n.a), in which h expresses the displacement of said work piston, n expresses the number of turns, and a expresses the forward advance after one turn of said helical piston; the effective displacement of the portion of the normal transversal section of said helical piston traveled insidc said helical tube is n.[(2mp)2 -I-a2], in which n is the number of turns, p is the average radius that originates the diameter of the turn of helicoid, and a is the linear longitudinal forward advance of one turn in regards to the longitudinal axis of said helical piston and of said helical tube.
3. 3. An activating mechanism according to claim 1 wherein a backstop undergoes a keyed or hex hole centered; an helical piston is soldered to said backstop orthogonally, making for an activation; said backstop is inserted by a rotary shaft and can move in displacement linear with its respect; said rotary shaft rotates around a hollowed shaft fixed on the chassis of a recipient; central portion of said hollowed shaft communicates two chambers of an oil container; the activation consisting of helical piston and backstop may bc displaced by his length alongside said rotary shaft fill course; top portion of said rotary shaft undergoes coupling to a worm wheel; said worm wheel will be driven by a worm screw with fulcrum in the chassis of the recipient; said activation displacement triggers helical piston extract and into an helical tube communicating with oil container chambers in the recipient.