GB2618572A

GB2618572A - Discharge system

Info

Publication number: GB2618572A
Application number: GB2206839.9A
Authority: GB
Inventors: John Warne Matthew; Singh Chatha Gaganpreet; Gordon Widger John
Original assignee: Camloc Motion Control Ltd
Current assignee: Camloc Motion Control Ltd
Priority date: 2022-05-10
Filing date: 2022-05-10
Publication date: 2023-11-15

Abstract

An adjustable position fluid strut (2, Figure 1) comprises a casing 4 comprising fluid and a piston 6. The position of the piston 6 within the casing 4 is selectively adjustable via an adjustment mechanism configured to selectively allow the fluid to pass therethrough. The strut 2 further comprises a pressure release mechanism comprising a valve 8 that is selectively operable to discharge the fluid from within the casing 4 directly to the ambient environment, and a discharge actuator 38 to provide operation of the valve 8, where at least a portion of actuator 38 protrudes out from the casing to allow actuation thereof.

Description

Discharge System The present invention relates to a discharge system for a fluid-positioning or piston device, and particularly but not limited to, to discharge system for a gas strut.

Background of the invention

A prior art gas strut is shown is shown in WO/8901578. The gas strut comprises a casing 1 with a plunger 16 received therein. The plunger 16 is sealed against the casing 1 with a seal 13. The plunger 16 comprises a valve arrangement 18 configured to selectively permit gas to flow either through the plunger 16 to fluidly connect the space within the casing either side of the seal 13. The valve arrangement therefore allows the position of the plunger 16 to be selectively adjusted.

A valve arrangement 7 allows charging/discharging of the space inside the casing. Typically, the valve 7 is used to refill the casing due to long term leakage of gas from the system. A plug 5 may then be used to seal the valve 7 to prevent tampering thereof.

Such systems may be used to adjust the vertical position of a chair or like. However, the inventor has found numerous problems with such prior art arrangements. Whilst the system allows discharge of the strut (e.g. through valve 7), the discharging must be performed via a specialised tool configured to be received within the space occupied by the plug 5. The plug 5 further prevents unintentional discharge. This may be detrimental where rapid discharge of the system is required.

For example, in a military vehicle, a seat may need to be lowered in the event an operator is incapacitated or the operator comes under fire etc. Using a specialised tool and releasing the plug etc., may simply take long and may be difficult to perform in stressful situations (e.g. when under fire). The prior art device is therefore not suitable for use where emergency discharge is required.

It is an aim of the present invention to overcome or ameliorate one or more of the above problems.

Statement of invention

According to a first aspect of the invention, there is provided: an adjustable position fluid strut comprising: a casing comprising fluid and a piston, the position of piston within the casing selectively adjustable via an adjustment mechanism configured to selectively allow the fluid to pass therethrough; a pressure release mechanism comprising a valve selectively operable to discharge the fluid from within the casing directly to the ambient environment; and a discharge actuator to provide operation of the valve, where at least a portion of actuator protrudes out from the casing to allow actuation thereof.

The actuator may comprise a lever or arm. The lever/arm may be rotatable or pivotable about a pivot point spaced from the portion of the actuator that protrudes out from the casing.

The strut may comprise a cavity and the lever is at least partially contained within the cavity. The cavity may be sized to allow rotation of the actuator therein. The cavity is provided in a fixing or mount for the strut. The piston may extend from the cavity at only one side or end of the cavity.

The pressure release mechanism may comprise a push type valve. The actuator may engage a stem of the pressure release mechanism in use. The actuator may comprise a recess or groove to receive the valve stem. The actuator may be provided at a lateral side of the strut.

The strut may comprise a guide configured to guide a flexible tension member attached to the actuator, in use. The guide may comprise a protruding flange. The guide may comprise an opening therein configured to receive the flexible tension member in use, the opening facing toward the actuator. The guide may be interposed between the casing and a mount/fixing for the strut. A portion of the pressure release mechanism may extend through the guide. The valve stem may extend through the guide.

The actuator may comprise a hook or recess for attachment of a flexible tension member in use. The pressure release mechanism forms or comprises a plug or cap configured to seal an end of the casing.

The adjustment mechanism comprises a manual actuator, the manual actuator provided at an opposing end of the strut with respect to the discharge actuator.

The strut may comprise a flexible tension member attached to the actuator to provide actuation thereof. The flexible tension member may comprise a handle or manual actuator.

The discharge actuator may extend laterally relative to a longitudinal axis of the casing. The discharge actuator may protrude laterally from the casing, i.e. outwardly from a side wall or envelope of the casing. A pivot point for the discharge actuator may be within the width dimension or envelope of the casing.

The pressure release mechanism and/or discharge actuator may be provided at an end of the strut.

According to a further aspect, there is provided: a seat or stand arrangement comprising the adjustment fluid piston of any preceding aspect. The seat or stand may be mounted to one end of the piston and the pressure release mechanism is provided at an opposing end of the piston.

According to a further aspect, there is provided: a vehicle comprising the seat of the preceding aspect. The vehicle may comprise a military vehicle. The piston may be mounted to a chassis of the vehicle.

According to a further aspect of the invention, there is provided: an adjustable position fluid strut comprising: a casing comprising fluid and a piston, the position of piston movable within the casing; a pressure release mechanism comprising a valve selectively operable to discharge the fluid from within the casing directly to the ambient environment; and a discharge actuator to provide operation of the valve, where at least a portion of actuator protrudes out from the casing to allow actuation thereof.

The piston may be selectively adjustable via an adjustment mechanism configured to selectively allow the fluid to pass therethrough. The piston may be selectively adjustable by frictionally engaging and/or interlocking with the casing.

Any optional or preferable features described in relation to any one aspect of the invention may be applied to any further aspect, wherever practicable.

Detailed Description

Practicable embodiments of the disclosure are described below in further detail, by way of example only, with reference to the accompanying drawings, of which: Figure 1 shows a schematic longitudinal section view of a gas strut; Figure 2 shows a perspective sectional view of a discharge mechanism of the gas strut; Figure 3 shows a schematic view of a seat mounted to the gas strut.

A gas strut 2 is shown in figure 1. The gas strut may be referred to as a gas spring, damper, shock absorber etc. Typically, the gas strut is filled with a gas, however, any suitable fluid (e.g. liquid or gas) may be used. The gas may comprise an inert gas, for example, Nitrogen.

The gas strut 2 comprises a casing 4. The casing 4 defines a substantially sealed chamber filled with the spring/damping fluid. The casing is elongate in form, i.e. having a longitudinal axis. The casing may be cylindrical/tubular in form.

20 25 30 A piston 6 is received within the casing 4. The piston 6 is movable within the casing to define an effective length or stroke of the strut. The piston 6 is selectively moveable via actuation of a valve mechanism 8. The valve mechanism 8 allows fluid to pass from one side of a head portion 10 of the piston 6 to the other side thereof, thereby allowing selective movement thereof. The strut 2 is therefore adjustable in length. When the valve mechanism is disengaged, the piston 6 is generally held in a fixed position (with limited movement provided by compression of the fluid). The valve mechanism 8 is otherwise conventional and will not be described in detail. The piston head 10 is sealed against the casing 2 via a seal/gasket 12.

Fixings (not shown) may attach either end 14,16 of the strut 2 to their respective support structures. For example, one end 14 of the strut 4 may fixed to a seat and the other end 16 may be fixed to the chassis of a vehicle. Fixings may include one or more of: fasteners; screw threads; eyelets; latches; bolts; hooks; hinges; pivots; ball joints etc. It can be appreciated that the ends 14,16 of the strut 2 can be attached to any suitable structure and/or in any suitable orientation.

The piston 6 comprises a manual actuator 18 configured to actuate the valve mechanism 8. The actuator 18 extends along the length of the piston 6. The actuator 18 is accessible at an end 14 of the strut 2. The actuator 18 may be operatively connected to a handle, lever or other manual actuator. The actuator passes along the length of the interior of the piston. The piston 6 may be biased in one direction relative to the casing 1. This allows the piston to be biased toward the retracted/extended position. For example, the piston 6 may be biased toward the extended position to bias a seat toward an upward position.

A discharge system 20 is shown in figure 2. The discharge system 20 is configured to discharge the fluid within the casing 4. This allows rapid movement of the piston 6 (i.e. much quicker than using the piston valve mechanism 8). The discharge system 20 may therefore be used in an emergency situation to effect movement of the piston 6.

The discharge system 20 comprises a valve arrangement 22 to selectively allow fluid communication between the cavity 24 defined by the casing 4 (i.e. the casing internal volume) and the ambient environment. The system therefore allows direct discharge of fluid from the cavity 22 to the ambient environment. As such, movement of the piston 6 when the valve 22 is open discharges fluid to the ambient environment.

The valve arrangement 22 comprises a valve block 26 configured to seal the end of the piston casing 4, e.g. defining a closed end wall of the casing. The block 26 therefore comprises a plug or seal. The valve block 26 may be sealed against the casing 4 via seal or gasket 28. The valve block 26 is retained via a flange 30 on the casing 4, e.g. defining an abutment for the valve block and/or an opening of reduced width relative to the width of the valve block. It can be appreciated that the block 26 may be secured using any suitable means, for example, one or more of: fasteners; welding; adhesives etc. A valve stem 32 is movably received within the block 26. The stem 32 is movable into/out of engagement with a valve seat 34 to allow select flow through the valve 22 (i.e. to provide a push type valve). The valve seat 34 may comprise a resilient seal or gasket 34. A stop 36 or retainer limits movement of the valve stem 32 (e.g. during depression thereof). In general, the valve stem 32 is biased into the closed position by pressure within the casing 1. In some embodiments, biasing means (e.g. a spring) may bias the valve stem 32 into the closed position.

A manual actuator 38 engages the valve stem 32 to provide actuation thereof. The actuator 38 comprises a lever. The lever is pivotally mounted to provide movement thereof. The actuator 38 rotates generally transversely to the axis of the strut 2, e.g. about an axis of rotation that extends transversely relative to the longitudinal axis of the strut.

The manual actuator 38, i.e. lever, is pivotably mounted at its end to the valve arrangement 22. The pivot point is maintained within the valve arrangement interior such that only a free end of the lever depends outwardly from the assembly, i.e. from the side of the strut 2. The casing 4 may define a lateral/width dimension of the strut 2 and the actuator 38 may protrude laterally beyond the width of the casing 4 and/or strut 2, i.e. beyond the enveloped of the strut.

The valve stem 32 engages the actuator 38 part way along the length thereof. The valve stem 32 thereby provides a fulcrum. The actuator comprises a rod or pin. The actuator 39 may comprise a circular/ovular cross-sectional profile.

The actuator 38 is contained with a cavity 40 on the strut 2. This helps to prevent accidental damages thereto or unintentional actuation thereof. The cavity 40 may be provided within a fixing or mount 42 for the strut 2. The cavity 40 may extend perpendicular/transversely with respect to the axial length of the strut 2. The actuator is therefore provided on a lateral side of the strut 2. The actuator 38 may therefore be more-readily accessible in use.

The cavity 40 is sized to allow sufficient rotation of the lever 38. That is to say a height/width dimension of the cavity is greater than the corresponding dimension of the actuator 38 to allow freedom of movement (e.g. rotation) of the actuator 38 in the cavity. The cavity 40 may limit the freedom of movement/rotation of the actuator to a few degrees, e.g. less than 20°, 15° or 100.

The cavity 40 may comprise a through-hole for ease of manufacture. However, the actuator 38 is generally accessible or actuable from one end of the cavity 40 (i.e. the upper side in figure 2). In some embodiments, the cavity 40 may comprise a blind hole/recess.

A portion of manual actuator 38 extends out from the cavity 40. The actuator 38 generally only extends out from one side of the cavity to help prevent unintentional actuation thereof. The protruding portion comprises an attachment formation 44.

The attachment formation 44 may be attached to a further manual actuator for actuation by the user. For example, further actuator may comprise a flexible tension member, such as a cable, wire, chain or the like. In embodiments, the attachment formation 44 may be connected to a lever, grip or handle. The formation 44 comprises a recess/channel. This defines a hook like arrangement.

A flange 46 extends outwardly from the casing 4 adjacent the actuator 38. The flange comprises an aperture 48 therein. A cable or like may connected to the actuator 38 may pass through the aperture 48. The flange 46 may therefore act as a guide. The flange 46 is sandwiched between the mount 42 and the casing flange 30. The flange 46 comprises an aperture to receive the valve block 26. The valve block 26 therefore extends through the flange 46.

The mount 42 may comprises fixing formations 50 thereon to allow attachment of the system as required. The fixing formations 50 may comprise apertures, screw threads or the like. The fixing formation 50 may be L-shaped. In some embodiments, the fixing formations comprise fasteners, screws etc. The strut 2 is shown is a typical usage condition in figure 3. A seat 52 is mounted to the piston 6. A lever/handle 54 is operatively connected to the actuator 18 to allow manual adjustment of the vertical position of the sea 52, as is conventional. The mount 42 may be fixed to a chassis of a vehicle (not shown). The vehicle may comprise a military light utility vehicle. Well known examples include a "Humvee".

In a typical configuration, the seat 52 is significantly elevated (e.g. by more than 0.5m or 1m), thereby allowing a gunner to protrude from the topside of the vehicle.

A cable 56 may be secured to the discharge lever 38. The cable 56 is passed through the flange 46. The cable 56 may comprise a handle or lever 58 to allow manual actuation thereof. The handle/lever 58 is provided at a location distal from the seat 52 (typically out of reach of the seat user in use). However, the handle/lever 56 is accessible from other occupants of the vehicle, thereby allowing the occupants to discharge the piston 2 and the lower the seat in a rapid fashion without the need to actuate the adjustment lever/handle 54. This defines just one usage scenario and it will be appreciated that other potential applications exist for a quick/emergency release for a strut of this type, Upon applying tension, the cable 56 brings the discharge lever 58 upward toward the discharge position, thus engaging the valve stem 32 and opening the valve. The flange 46 ensures the cable 56 is moved in an upward direction, regardless of the pull direction of the cable 56 (e.g. acts as a pulley).

It can be appreciated that other discharge valve types may be used. For example, a rotatable valve may be used. The lever 38 may therefore be rotatable about the axial direction. Lever type actuators are preferred as they provided leverage for the user and provide a large area for the user to grasp, which are beneficial in areas where users may need rapid discharge when under pressure. The travel distance of such levers is relatively small, e.g. a minor fraction of a rotation, allowing quick and simple operation. They also allow the use of a cable or the like for operation. However, in some embodiments, the valve stem 32 could be operatively connected to a push type actuator. For example, the valve stem 32 may comprise a T-shaped handle or grip.

Typically, the discharge mechanism is used to only discharge the strut 2. In some embodiments, the discharge opening/mechanism may be engageable by a hose connector or the like to allow refilling of the strut 2. The discharge mechanism is provided at an operative end of the strut 2. The discharge mechanism is provided at an end of the strut 16 opposite the piston actuator 18. In some embodiments, the discharge mechanism may be located part way along the strut (e.g. provided on a side wall thereof).

It can be appreciated that the strut 2 can be used to support or elevate any suitable apparatus, for example, any of: seating; stands; tables; mounted weapons etc. It can be appreciated that the piston casing 4 and the mount 42 collectively provide a casing or housing for the strut. The lever 38 thus protrudes at least partially from the casing/housing for the strut.

Although the present invention may be used with a locking type strut, it can be appreciated that any suitable strut or piston arrangement may be used. For example, the piston may comprise a gas spring or a dampener. In the general terms, the piston is movable along/within the casing to between two or more positions to extend/retract the strut. In some embodiments, the piston may frictionally engage and/or interlock with the casing to prevent movement thereof.

The present arrangements allows rapid discharge of gas strut. The discharge mechanism comprises an easily actuable system that is accessible and quick to use in high-pressure environments. The system requires no specialised tools, and is simple and robust, thus providing a reliable system. The system allows movement of piston from positions, thereby allowing multiple users to control the system.

Claims

Claims 1. An adjustable position fluid strut comprising: a casing comprising fluid and a piston, the position of piston within the casing selectively adjustable via an adjustment mechanism configured to selectively allow the fluid to pass therethrough; a pressure release mechanism comprising a valve selectively operable to discharge the fluid from within the casing directly to the ambient environment; and a discharge actuator to provide operation of the valve, where at least a portion of actuator protrudes out from the casing to allow actuation thereof.
2. A strut according to claim 1, where the actuator comprises a lever.
3. A strut according to claim 2, where the lever is rotatable or pivotable about a pivot point spaced from the portion of the actuator that protrudes out from the casing.
4. A strut according to any preceding claim, where the strut comprises a cavity and the lever is at least partially contained within the cavity.
S. A strut according to claim 4, where the cavity is sized to allow rotation of the actuator therein.
6. A strut according to any of claims 4 or 5, where the cavity is provided in a fixing or mount for the strut.
7. A strut according to any of claims 4 or 5, where the piston extends from the cavity at only one side or end of the cavity.
8. A strut according to any preceding claim, where the pressure release mechanism comprises a push type valve.
9. A strut according to claim 8, where the actuator engages a stem of the pressure release mechanism in use.
10. A strut according to any of claims 8 or 9, where the actuator comprises a recess or groove to receive the valve stem.
11. A strut according to any preceding claim, where the actuator is provided at a lateral side of the strut.
12. A strut according to any preceding claim, comprising a guide configured to guide a flexible tension member attached to the actuator, in use.
13. A strut according to claim 12, where the guide comprises a protruding flange.
14. A strut according to any of claims 12 or 13, where the guide comprises an opening therein configured to receive the flexible tension member in use, the opening facing toward the actuator.
15. A strut according to any of claims 12-14, where the guide is interposed between a piston casing and the mount/fixing for the strut.
16. A strut according to any of claims 12-15, where a portion of the pressure release mechanism extends through the guide.
17. A strut according to any of claims 12-16, where the valve stem extends through the guide.
18. A strut according to any preceding claim, where the actuator comprises a hook or recess for attachment of a flexible tension member in use.
19. A strut according to any preceding claim, where the pressure release mechanism forms or comprises a plug or cap configured to seal an end of a cavity for the piston.
20. A strut according to any preceding claim, where the adjustment mechanism comprises a manual actuator, the manual actuator provided at an opposing end of the strut with respect to the discharge actuator.
21. A strut according to any preceding claim, comprising a flexible tension member attached to the actuator to provide actuation thereof.
22. A strut according to claim 21, where the flexible tension member comprises a handle or manual actuator.
23. A seat or stand arrangement comprising the adjustment fluid piston of any preceding claim.
24. A seat or stand arrangement according to claim 23, where the seat or stand is mounted to one end of the piston and the pressure release mechanism is provided at an opposing end of the piston.
25. A vehicle comprising the seat of claims 23 or 24.