JPS6170238A - Extensible strut - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] field of invention This invention relates to a telescoping column.

One example is the use of such posts in supporting an office chair while still allowing for changes in the height of the office chair. Such struts are often filled with a compressible fluid, usually a gas, but they may also be filled with an incompressible fluid such as oil.

SUMMARY OF THE INVENTION According to one aspect of the present invention, the fiber increases and stretches without any steps;
The lockable telescoping column has an outer cylinder separated by a piston into first and second chambers, and an inner cylinder extending through the piston, the first and second chambers being opened when a valve associated with the inner cylinder is opened. and a second chamber.

A fluid seal is provided between the piston and the inner wall of the outer cylinder and between the piston and the outer wall of the inner cylinder. The inner cylinder preferably extends substantially the length of the outer cylinder and is at or adjacent to the end of the outer cylinder away from the end of the outer cylinder through which the piston rod attached to said piston passes. It is connected to the external cylinder at the point where it connects to the external cylinder. The connection between the inner cylinder and the outer cylinder is therefore preferably at a point outside the normal travel range of the piston within the outer cylinder.

The configuration of the valve in which the passage of fluid between the inner cylinder and the outer cylinder occurs is preferably at or adjacent to the point where the inner cylinder is connected to the outer cylinder and also when the valve is opened or closed. The normal movement of the piston in the external cylinder at'! It is preferably located at a point outside the + range. Alternatively, and according to a particularly preferred aspect of the invention, the valve and internal cylinder are constructed as a unit. In this type, the valve/inner cylinder unit includes a tube that is sealed at its outer end and extends through a sealing arrangement at the end of the outer cylinder. Such a configuration allows pressure at the outer end of the valve/cylinder couple to cause an otherwise obstructed passage to the interior of the inner cylinder to communicate with the interior of the outer cylinder and thereby allow fluid to flow between the two. can pass between the two. In this form of the invention, the internal cylinder can be thought of as an extension of the valve body. Seven flanges, formed on the cylinder by welding or for example by crimping of the cylinder faces, are provided to limit the movement of the inner cylinder and the seal therebetween with respect to the outer cylinder.

According to another aspect of the invention, the invention has a sealed cylinder containing a fluid, a piston fitted to the cylinder and sealed to the cylinder wall, and a closed end extending from one side of the piston and extending from one end of the cylinder. a hollow piston rod; a hollow drive rod extending axially through the piston in communication with the hollow piston rod and through the other end of the cylinder to its closed end; and a hollow drive rod extending from one side of the piston to the other side. A telescoping strut is provided with valve means actuatable by axial displacement of the drive rod to open and close fluid communication to the retractable strut.

The valve means preferably seals the outermost end of the drive rod and is provided with an aperture passing through the wall of the hollow piston rod on said one side of the piston (where the outer diameter of the drive rod is equal to the inner diameter of the piston rod). an annular fluid passageway therebetween), an aperture passing through the wall of the drive rod, and the aperture passing through the wall typically being occluded;
The interior of the drive rod is provided by configuring the drive rod so that it can be axially displaced so as to be able to communicate with the fluid space of the cylinder on the other side of the piston.

The aperture through the wall of the drive rod is obstructed by a plug fitted to one end of the cylinder into which the aperture enters when the drive rod is not axially displaced. The plug is
It includes a pair of O-rings that seal around the drive rod on either side of the aperture, thereby forming a spool valve.

The portion of the drive rod containing the aperture may be constricted so that the edges of the aperture do not move relative to the O-ring seals which may reduce the life of these seals.

The cylinder is preferably provided with a lubricated or self-lubricated seal, preferably at the end from which the piston rod extends! sealed.

In other aspects, the invention includes a sealed cylinder containing a fluid, a piston fitted into the cylinder and sealed to the cylinder wall, and a hollow cylinder extending from one side of the piston and extending outwardly from one end of the cylinder. a piston rod; and a hollow drive rod extending axially in the cylinder on the other side of the piston, one end of the drive rod extending from the other end of the cylinder and the other end of the drive rod extending through the piston and the piston rod. a telescoping cylinder having such a hollow drive rod inside the piston and valve means actuatable by axial displacement of the drive rod to unclose fluid communication from one side of the piston to the other side of the piston; Provide a strong support.

The fluid is preferably compressible, preferably a gas.

The valve means may be provided as described above and can be made very simply.

A strut is preferably used with a piston rod projecting downwardly from the cylinder and an exposed end of a drive rod at the top of the strut. The seal closing the bottom end of the cylinder consists of two back-to-back seals to prevent fluid from exiting the cylinder and also to avoid the possibility of any foreign material entering the cylinder under extreme conditions of use. May include.

According to yet another aspect of the invention, a sealed cylinder is provided with two pistons in the cylinder, a first of the pistons defining a first space containing an incompressible fluid and a second piston defining a first space containing an incompressible fluid. a piston rod located in one space, separated from a second space containing a compressible fluid, extending in the axial direction of a piston rod and strut connected to the second piston, and extending through the second piston; a drive rod extending from one side to the other and actuated by axial displacement of the drive rod to open and close fluid communication from one side of the second piston to the other side of the second piston;
ft valve means is provided.

The use of an incompressible fluid that occupies a major portion of the internal volume of the cylinder allows the strut to be relatively rigid when locked. In contrast, when a gas or other compressible fluid is used,
The struts have half the "resilience" they have when locked.

The valve means may be constructed similarly to that described above.

The first piston is preferably freely movable in the cylinder in response to fluid pressure on either side, but may be limited by a fixed stop in the cylinder in the incompressible fluid space. Furthermore, it may be advantageous to provide a second stop on the other side of the first piston. The first piston may be on the piston rod side of the second piston.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The strut shown in FIG. 1 has a cylinder 10 containing a piston 12. The piston 12 is sealed against the cylinder wall by an O-ring 14. Both ends of cylinder 10 are closed by plugs 16 and 18. A hollow biston rod 20 extends from the piston 12 and extends from the right side of the cylinder.
I! ! Extending outward from the I end (shown in Figure 1). The end of the piston rod 20 is closed by a plug 22. An aperture 24 in the wall of the piston rod 20 allows communication between the interior of the cylinder to the right of the piston 12 and the interior of the piston rod.

The illustrated struts contain gas under pressure. of the O-ring seal 14 and of the seals of the end plugs 16 and 18;
In order to maintain an efficient haze, Shoichi's rA lubricant is introduced into the cylinder 10 during assembly.

Kakeru! The IIO tube 26 is also hollow and is closed at its outer end by a plug 28. The drive rod extends through the piston 12 into the interior of the piston rod 2o, where the drive rod is sealed by an O-ring 30. The drive rod is provided with an enlarged part 32 in the releasing direction, and this enlarged part 32 controls the movement of the outer shell of the cylinder. It has an aperture 34 for communication.

In the position shown in FIG. 1, gas under pressure is contained within the cylinder on either side of the piston 12.

However, there is no weight that could cause gas to escape from one side of the piston to the other.

Therefore, the struts are locked, although there may be flea resiliency resulting from the compressibility of the gas. Abachi t? It can be seen that O-rings 38 and 40 are occluded within the plug 36 with J2 cut.

To adjust the length of the strut, actuator rod 2
6 is pushed axially into the cylinder. When this occurs, the aperture 1-34 communicates with the interior of the cylinder on the left side of the piston 12 and gas flows 19 from one side of the piston to the other. At that time, if there is a load on the piston rod 2o, the piston 12 moves to the left, and the gas from the left side of the piston passes along the hollow view of the rod 26, passes through the averge 1-34, and enters the hollow interior of the rod 20. , exits through the aperture 24 and enters the cylinder 10 to the right of the piston 12 .

If the actuator rod 26 is pushed in when there is no load on the piston rod 20, the piston will move in the opposite direction and gas will flow in the opposite direction to that just described.

Figure 2 shows the same components 3 as Figure 1, but
In FIG. 2, the end of the cylinder 10 is tapered so that the bracing can be used in applications where a standard size tapered end is required to fit standard end fittings. It can be used for

FIG. 7 shows an alternative assembly in which the end of the cylinder 10 is provided with a taper. Here, plugs 16 and 36
and O-rings 38 and 40 are fitted to the ends of the parallel sections of the cylinder and therefore do not need to mate with the tapered walls of the cylinder.

The drive member needs to be exposed at the end of the cylinder 10. For this purpose, the drive rod 26 can be extended through the tapered end of the cylinder, or
Slidable plug 39 with boss 41 as shown
can be used to transmit drive pressure to the drive rod.

FIG. 3 shows drive rod 26 alone. It can be seen that the rod is expanded to provide an abutment 32 that limits outward movement of the rod relative to the cylinder 10.

FIG. 4 shows a modification in which the diameter of the portion of the rod 24 that includes the aperture 34 is reduced. Is this Abachi? 3
4 from contacting the O-rings 38 and 40. Since the aperture must travel at least past the O-ring 38 during its actuation, it is important that the O-ring does not wear against the edge of the aperture, and the variant shown in FIG. This will prevent the necessary wear from occurring.

FIG. 5 shows a strut for use with non-compressible media inside the cylinder. Oil is an example of such a medium. In some applications, it may be advantageous to use a non-compressible medium, as this makes the strut more rigid when locked.

However, as the struts extend or contract, cylinder 10, drive rod 26 and piston rod 20
The trapped volume of changes. Non-compressible fluids cannot cope with such variations in volume, so it is necessary to provide a feature that provides compensation for such variations in the moving cylinder volume.

In FIG. 5, parts that are equivalent to those shown in FIGS. 1 and 2 are given the same reference numerals.

In FIG. 5, the cylinder is provided with an auxiliary piston 50. This auxiliary piston moves freely in the cylinder,
and separates the oil-filled space 58 on its left from the air-filled space 54 on its right. The piston is displaced as a result of pressure being applied on either side.

Internal O-ring 52 moves on piston rod 20 to seal the piston. An external O-ring 56 seals the piston 50 against the cylinder wall.

In use, the piston 12 moves along the cylinder in the same manner as described for the previous embodiment, and oil transfers from one side of the piston 60 to the other 111158. As the piston moves to the right, the internal volume of the combined oil spaces 58 and 6o increases slightly, and this increase is due to the expansion of the air in space 54 and the resulting movement of the auxiliary piston 5° to the left. Absorbed. The opposite effect occurs when piston 12 moves in the other direction.

FIG. 6 shows one type of oiled seal that can be used adjacent the end plug 18 to limit the air-filled space. This seal is held in place by an annular rib 62 formed from the outside of the cylinder wall. Disk 64 retains O-ring 66 in an annular cavity in metal support member 68. There is a rubber sealing ring at the other end of the support 68 that prevents the oil contained in the space 69 from leaking out. Oil lubricates the O-ring 66, which acts as a seal to keep the air space 54 airtight.

FIG. 7 shows an alternative seal 67 with multiple annular ribs in contact with rod 20. FIG. If necessary, the grooves between the ribs may be filled with grease. moreover.

Or alternatively, a nylon, ptfe or acetal bushing 65 may be included to reduce piston rod friction. Perhaps Seal 67 itself is low I! ! ! It will consist of rubbing substance.

FIG. 8 shows a telescoping support according to the invention for use in an office chair. The pillar 10 is the base 78 of the chair.
It is positioned by a guide bushing 84 which is secured to an external support tube 82 which is supported by a guide bushing 84 . Base 78 is caster 8
0 and the lower end of tube 82 is supported by a thrust swivel bearing shown at 76 to crotch. The lower end of the strut 10 is attached to a seat frame frame 72 that supports a seat cushion 70. An actuation knob 74 is movable to actuate the button 26 on the telescoping post. Thus, by movement of the knob 74, the valve means of the strut 10 are spaced, and thereby the effective length of the strut can be varied in stepless increments, making it possible to adjust the height of the seat. can.

In the previous embodiment, the rod 26 is axially movable in the outer cylinder and forms the drive rod. Although this is desirable, it is not essential.

The embodiment of FIG. 9 shows an internal displacement tube 86 that is axially fixed in an external cylinder 88. One end of the tube 86 is attached to or integral with an end plug 90 having an annular recess 92 communicating with an axial passageway 94 extending through the plug 90.

``The valve body 95 and adjacent external end plug 96 fit into an openable actuation rod or button 98 of the valve means. Body 95 has a passageway 102 that communicates with annular depression 92 and passageway 94 .

In the closed position of the valve means (as shown in Figure 9),
Chamber 1 at one end inside the internal transfer tube 86
04 is removed from passage 102 by O-ring seal 108. When the actuation rod or button 98 is moved to the right as shown in FIG. will be placed.

W! It will be appreciated that the right end of 86 projects through piston 14 and extends into hollow piston rod 20, as in the embodiment of FIG. Therefore, chamber 10
4 is placed in communication with the passage 102, the piston 1
Both sides of 4 are arranged in communication in a manner comparable to the previously described embodiments.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a first embodiment of a strut according to the invention. FIG. 2 shows details of one end of the modification of the column shown in FIG. FIG. 3 is a detailed view of the drive rod section. FIG. 4 is a detailed #II1 view of a portion of the modified drive rod. FIG. 5 is a sectional view of a second embodiment of the strut according to the invention. 6 is a detailed view of a portion of the strut of FIG. 5; FIG. The seventh factor is a cross-sectional view of a third embodiment of the strut according to the invention. FIG. 8 shows a practical application of the strut according to the invention. FIG. 9 is a fragmentary view of another embodiment of the strut according to the invention. In the figure, 10 is a cylinder, 12 is a piston, 14 is an O-ring, 16 and 18 are plugs, 20 is a hollow piston rod, 22 and 28 are plugs, and 26 is a drive rod.

Claims (15)

[Claims] (1) A lockable telescoping column that extends in stepwise increments, comprising an outer cylinder divided into first and second chambers by a piston, and an inner cylinder extending through the piston; The inner cylinder is a telescoping strut connecting the first and second chambers when a valve associated with the inner cylinder is opened. (2) The inner cylinder is axially displaceable within the outer cylinder, and the valve means is operable as a result of axial movement of the inner cylinder.
Telescoping support as described in section. (3) The inner cylinder is not axially movable with respect to the outer cylinder, and the valve means is actuatable depending on the axial displacement of a slidable drive member with respect to the outer cylinder. A telescoping support according to scope 1. (4) a sealed cylinder containing a fluid; a piston fitted into the cylinder and sealed to the cylinder wall; a hollow piston rod extending from one side of the piston and extending from one end of the cylinder; a hollow drive rod extending axially in the cylinder on the other side;
One end of the drive rod extends from the other end of the cylinder and the other end of the drive rod extends through the piston and is inside the piston rod, and further opens and closes fluid communication from one side of the piston to the other side. a telescoping strut with valve means actuatable by axial displacement of the drive rod to (5) The strut according to claim 4, wherein the fluid is a compressible fluid. (6) The strut according to claim 5, wherein the compressible fluid is a gas. (7) the hollow drive rod is sealed at its outermost end, and an aperture is provided through the wall of the hollow piston rod on said one side of the piston, between the outer diameter of the drive rod and the inner diameter of the piston rod; has an annular fluid passage in which a second aperture is provided through the wall of the drive rod which is normally obstructed but is exposed when there is an axial displacement of the drive rod, the two apertures as well as the piston 5. A strut according to claim 4, which communicates via an annular passage between the fluid spaces of the cylinder on both sides of the cylinder. (8) The second aperture is obstructed by a plug fitted to one end of a cylinder through which the drive rod passes and in which the second aperture is normally aligned. The pillar of. (9) The strut of claim 8, wherein the plug includes a pair of O-ring seals formed by a spool valve. 10. The strut of claim 9, wherein the portion of the drive rod that includes the aperture is constricted so that the edge of the aperture does not move relative to the O-ring seal. (11) the cylinder is sealed to the end from which the piston rod extends by a lubricated or self-lubricated seal;
A strut according to any one of claims 4 to 10. 12. The strut of claim 11, wherein the seal closing the bottom end of the cylinder includes two back-to-back seals. (13) a sealed cylinder with two pistons, a first of the pistons separating a first space containing an incompressible fluid from a second space containing a compressible fluid; a second piston located in the first space; a piston rod connected to the second piston;
a drive rod extending axially through the strut and extending through the second location; and actuatable by axial displacement of the drive rod to open and close fluid communication from one side of the second piston to the other side. A telescopic column. (14) The first piston is freely movable in the cylinder in response to fluid pressure on either side, but is limited by a stop fixed to the cylinder in an incompressible fluid space. The support described in item 13. (15) The strut according to claim 12, wherein a second stop is provided on the other side of the first piston.