Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/20—Other details, e.g. assembly with regulating devices
  • F15B15/26—Locking mechanisms
• • E—FIXED CONSTRUCTIONS
  • E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
  • E05C—BOLTS OR FASTENING DEVICES FOR WINGS, SPECIALLY FOR DOORS OR WINDOWS
  • E05C17/00—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith
  • E05C17/02—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith by mechanical means
  • E05C17/04—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith by mechanical means with a movable bar or equivalent member extending between frame and wing
  • E05C17/30—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith by mechanical means with a movable bar or equivalent member extending between frame and wing of extensible, e.g. telescopic, construction
  • E05C17/305—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith by mechanical means with a movable bar or equivalent member extending between frame and wing of extensible, e.g. telescopic, construction with hydraulic locks

Definitions

• This invention relates to an adjustment bar which has a variable length.
• adjustment bar is a stabilising bar which is used on tractors and other agricultural vehicles to reduce or eliminate any undesirable sideways movement of agricultural implements attached to the vehicles.
• Stabilising bars generally comprise two rod members which are externally threaded with opposite pitch relative to each other.
• the rod members are mutually engagable into an internal threaded pipe.
• the pipe is rotated.
• nuts on the rod members are threaded until they contact the end of the pipe.
• Agricultural implements are usually attached to arms extending from the tractor.
• the stabilising bars are attached to the body of the tractor and to the tractor arms. The length of the stabilising bar is adjusted prior to the implement being attached or removed from the tractor arms.
• adjusting the stabilising bars of the configuration described above is slow and labour intensive. Further, the bars are difficult to adjust in confined spaces.
• Adjustment bars in the form of struts are used to control the rate that a door closes. These are essentially single acting hydraulic or pneumatic devices which can be locked to prevent movement in one direction only. Therefore, these devices will not be useful in situations where a adjustable variable length bar is required to prevent movement in more than one direction.
• a further disadvantage of the air or gas operated struts is that they cannot be used in aircraft.
• Hydraulic rams are known in single acting and double acting forms. However, hydraulic rams have a number of disadvantages. One disadvantage is that usually there is required to be a separate hydraulic pumping system to activate the ram. This system is understandably bulky and expensive and inappropriate for use in situations where a variable length bar is required to be used as a stabiliser bar and the like.
• an apparatus for adjusting the position of a bar with respect to a housing comprising housing having at least two chambers defined by the bar or an attachment or attachments thereto wherein movement of the bar is effected by fluid flow through a fluid transfer link from one chamber into another chamber.
• the housing may be divided into any number of chambers, but for ease of reference throughout this specification the housing shall be referred to as being divided into two chambers.
• a fluid in this specification is defined as any transferable flowable material such as a gas, liquid or particulate material.
• apparatus for adjusting a bar substantially as described above wherein there is provided locking means for locking the bar into position by interrupting fluid flow between the chambers.
• this invention allows quick adjustment of the effective length a bar using fluid transfer between two chambers, wherein stopping the fluid flow locks the bar into position.
• a cylinder is used for the housing of the adjustment bar and reference throughout this specification shall be made to the housing as being a cylinder. It must be appreciated however that any suitable housing may be used but preferably with a constant internal cross-sectional shape.
• the cylinder may be made of metal but any other suitable material may be used, such as polymers, ceramics, composites or other materials.
• Preferably the cylinder has a smooth internal surface which will be beneficial for sealing and to reduce friction and wear in the functioning of the device.
• the heads of the cylinders may be held in the cylinder by screw threads, welded, friction fitted or by other means to locate the head to the cylinder.
• a suitable aperture can be provided for in each head through which the bar can pass.
• the bar is of constant cross-section except for the part which defines the chambers. This ensures that the absolute volume change in both chambers is constant when the bar is moved.
• the part or parts of the bar which divides the housing into the two chambers or the attachment to the bar which performs the same task shall now be referred to as a piston or pistons.
• each chamber can be filled with a fluid such as oil or water but it must be appreciated that any suitable fluid may fulfil this role. If the fluid is substantially non-compressible, preventing fluid flow between the chambers by a valve or tap will rigidly lock the bar into position.
• a fluid such as oil or water but it must be appreciated that any suitable fluid may fulfil this role. If the fluid is substantially non-compressible, preventing fluid flow between the chambers by a valve or tap will rigidly lock the bar into position.
• the chamber can be filled with a compressible media such as air, combination of hydraulic fluid and air or any compressible gas, liquid or combination. This can then act as a shock absorption device as the bar will be allowed some movement to overcome shocks imposed during use from not being rigidly held into position.
• a compressible media such as air, combination of hydraulic fluid and air or any compressible gas, liquid or combination.
• Each fluid chamber may have an aperture to which the fluid transfer link can be attached.
• the fluid transfer link can comprise a hose, tube, closed groove or any other suitable means.
• the fluid transfer link may be positioned in various configurations with respect to the housing.
• the fluid transfer link is a tube which is positioned external to the housing.
• the fluid transfer link is actually positioned within the bar itself and the only part of the fluid transfer link external to the housing is the part which attaches to the valve or tap.
• the fluid transfer link may be internal to the adjustment bar.
• a central divider which is fixed to the inside of the cylinder, through which the bar passes.
• This central divider may include the fluid transfer link.
• the bar may have attached to it heads near the ends of the cylinder which help define the chambers within the cylinder. Movement of the bar causes the heads to likewise move pushing fluid through the fluid transfer link.
• a valve associated with the fluid transfer link can be used to control the flow fluid. Shutting the valve can stop the bar moving and lock it into position.
• the fluid transfer link may have a number of additional features and not be just a simple fluid conduit.
• the fluid transfer link may have within it a floating piston in which there is a passage way through fluid can pass.
• This piston may be associated with shock absorbing means such as springs.
• shock absorbing means such as springs.
• Such an arrangement means that although the stabiliser bar can be set to an approximate length, some movement in the bar is allowed. This can be of use in situations whereby it is preferred that implements such as ploughs can float somewhat with respect to the vehicle that they are attached to.
• an adjustable stroke limiter In addition to shock absorbing means (say springs) there may be provided an adjustable stroke limiter. This can come in a variety of forms and in one embodiment may be a pair of screws positioned on either side of the floating piston. The screws may be wound in and out to the appropriate distance to allow maximum movement of the floating piston.
• the tap on the transfer link needs to have an adjustable orifice such as that found with needle valves. Otherwise, a separate fluid transfer link is required with the tap only capable of providing a fully open or closed orifice. In that embodiment the floating piston transfer link should have smaller apertures than that of the main fluid transfer link.
• the apertures of the fluid transfer link will be near the cylinder heads so as to allow maximum travel of the bar within the cylinder housing. If there is a small gap between the apertures and the cylinder heads, then the fluid in this gap trapped between the piston on the bar and the cylinder head can act as a buffer preventing physical contact with the head and the piston as instead the fluid is compressed between the head and the piston.
• Appropriate sealing means such as O-rings may be used in the present invention to prevent leakage of the fluid.
• the fluid transfer link may have a fluid control means attached which is the locking means of the present invention.
• This fluid control means may be a tap, valve, or any other suitable control means. Throughout this specification the control means will be referred to as a tap.
• a tap can control the rate of fluid transfer from one chamber to the other by limiting the aperture through which the fluid can flow (such as with a needle valve). When the tap is in an open position the fluid can freely flow from one chamber to the other. When the tap is closed, the fluid flow is stopped and movement of the piston is halted and with an incompressible fluid the bar is locked into position.
• the tap can be controlled by a number means. In preferred embodiments, the tap is manually controlled by twisting same to expose or shut off an aperture which allows fluid to flow through same. In some embodiments, the tap can be remotely controlled for example by hydraulics or electronic means. Other methods of control are envisaged.
• the bar may have a central piston attached to it as described previously, but with the fluid transfer link within the piston itself.
• This fluid transfer link may have a valve associated with it which extends outside the piston.
• the adjustment bar may have a biasing means attached.
• the biasing means will be referred to as a spring but it must be appreciated that other means may be used such as elastic materials.
• the spring may be attached at one or both ends. An arrangement of the spring at either end may be used to return the bar to its original position when the fluid is free to flow.
• a floating head within the fluid chamber.
• the floating head can act as a shock absorbing means.
• the floating head may be fluid- tight so that incompressible liquid in the form of oil or water may be on one side of the floating head and a compressible fluid such as air on the other side of the head.
• incompressible liquid in the form of oil or water may be on one side of the floating head and a compressible fluid such as air on the other side of the head.
• shock absorbing means may be used.
• resilient rubber means which can absorb the impact of the piston against the cylinder head.
• a shock absorbing means in the form of air filled pockets may be provided.
• the adjustment bar may be moved with respect to the housing by a variety of means. It is envisaged that when the adjustment bar is used as a stabilising bar for tractors, the bar will most likely to be moved by manual means. However, in other embodiments the adjustment bar may be moved by hydraulic, pneumatic or mechanical means.
• mechanical means may come in the form of a screw or lever which applies pressure to the bar (or heads associated with it).
• the present invention offers a compact and inexpensive means by which the effective length of a bar can be varied. Further, the fact that a gravity dependent reservoir is not required means that the present invention can be used in any position or orientation.
• Further locking means in the form of a fluid control means is a very simple way by which a bar can be locked into position and there is no need to rely on friction bearing locking means. And, unlike most mechanical locking means the present invention enables the bar to be adjusted to any length without the requirement of discrete steps such as in a ratchet system or pin and aperture systems.
• This invention may be used in many situations including as a stabilising bar for limiting lateral movement of tractor implements. This invention provides quick and easy adjustment so that implements may be attached or removed from the bottom link of. the tractor arms which hold the implement to be stabilised.
• Another possible use of the present invention is for holding gates, doors or windows and so forth open or closed.
• the configuration of the bar can swivel (or not as desired) and this feature can possibly be used in a variety of situations.
• the adjustment bar may be used as either a single acting displacement ram or a double acting ram.
• the present invention may be configured so that it can be pressurised to either extend or withdraw the adjustment bar with respect to the housing. Once pressurised, the adjustment bar can be locked into position using a standard tap on the fluid transfer link enabling the pressurising means to be removed from the adjustment bar. This is particularly useful in situations whereby the bar is required to withstand great pressure, for example when used in preventing a drain in collapsing.
• Figure 1 is a cross-sectional view of an adjustment bar in accordance with one embodiment of the present invention.
• Figure 2 is a cross-sectional view of an alternative embodiment of the present invention
• Figure 3 is a cross-sectional view of an alternative embodiment of the present invention
• Figure 4 is a cross-sectional view of an alternative embodiment of the present invention.
• Figure 5 is a cross-sectional view of an alternative embodiment of the present invention.
• Figure 1 illustrates a cross sectional view of an adjustment bar generally indicated by arrow 1.
• a cylinder 2 with a smooth internal bore forms the housing for the bar 1.
• Heads 3 are joined to the ends of the cy Under 2 and a circular aperture is centrally located in each head 3.
• a bar 4 of constant cylindrical cross sectional area passes through the entire length of the cylinder 2 and protrudes through the heads 3.
• the minimum length of the bar 4 is such that during movement of the bar 4 within the cylinder 2, any end of the bar 4 will not pass through the aperture in the heads 3.
• a piston 5 which forms a fluid-tight interface with the internal surface of the cylinder 2.
• the piston 5 creates two chambers 6 and 7 within the cylinder 2.
• Hydraulic fluid 8 fills both chambers 6 and 7.
• each head 3 Near each head 3 are apertures 13 in the cylinder 2 to which a fluid transfer link in the form of a tube 9 is attached. This allows hydraulic fluid 8 to flow between chambers 6 and 7 when the bar 4 is moved.
• the tube 9 has a locking means in the form of a tap 10 to adjust fluid flow between the chambers 6 and 7. As described, when the tap 10 is open, hydraulic fluid 8 can flow from chambers 6 and 7 to move the bar 4. To stop the movement of the bar 4, the tap 10 can be closed to prevent hydraulic fluid 8 from transferring from either chamber 6 or 7. With the tap 10 closed the incompressible fluid will lock the bar 4 into position and prevent movement in either direction.
• Seals 11 are located between the bar 4 and heads 3 and between the double acting piston 5 and the cylinder 2. The seals 11 prevent hydraulic fluid 8 from leaking to other sections.
• a compression spring (not shown) may be located at one or two ends of the cylinder.
• Compression springs may be located at either end so that the bar 4 may be biased to a central position. When the tap 10 is open the device may operate to adjust the bar 4 and then be returned to the central position.
• the fluid 8 used is compressible.
• the double acting piston 5 moves freely towards either head 3.
• the tap 10 is closed the double acting piston 5 can be moved to balance the force on the bar 4. This will absorb any shock imposed on the bar 4 to prevent possible damage.
• Figure 2 illustrates an alternative embodiment of the present invention. In this embodiment there is a central partition 5a which is fixed with respect to the housing 2a. The bar 4a passes through this housing as does a fluid transfer link in the form of a passage 9a.
• pistons 14 and 15 Attached to either end of the bar 4a are pistons 14 and 15 which move with the bar 4a with respect to the housing 2a.
• the pistons 14 and 15 therefore act to define the chambers within the housing 2a.
• a valve in a the form of a tap 10a can close off the passage 9a within the central divider 5a, thus locking the bar 4a into position. Opening the valve 10a allows the bar and the pistons 14 and 15 to move within the housing 2a.
• Figure 3 illustrates yet another embodiment of the present invention.
• the fluid transfer link 9b is internal to the bar 4b having apertures 13b on opposing sides of the piston 5b and the bar 4b. Internalising the fluid transfer link 9b provides a compact unit which can be used in a variety of situations. The only external part of the fluid transfer link 9b is where it attaches to the tap 10b which preferably is readily assessable.
• Figure 4 is an embodiment of the present invention which allows modest movement of the stabiliser bar 4c.
• the fluid transfer link 9c has additional features.
• One of the additional features is a floating piston 16 which has a secondary fluid transfer link in the form of a passage 17 passing through it.
• springs 18 On either side of the piston 16 are springs 18 which bear against the piston 16 and the internal surfaces of the fluid transfer link 9c.
• the springs 18 surround screws 19 which can be wound in or out to limit the maximum amount of movement permitted by the floating piston 16.
• the tap 10c has an adjustable orifice so that different amounts of fluid flow can pass through the fluid transfer link.
• the tap 10c may be a needle valve. It can be appreciated that this embodiment of the present invention will be useful in stabilising bars used on tractor arms attached to ploughs which ideally should have a slight floating movement.
• Figure 5 illustrates an embodiment of the present invention which can be used as a double acting ram.
• the bar generally indicated by numeral Id, has additional housing 20 in which a second movable piston 21 attached to the bar 4d is enclosed.
• the housing 20 has vent holes 22 and 23 positioned on either side of the piston 21.
• the housing 20 can be pressurised through the vent holes 22 and 23 until the ram is held into its desired position or length.
• the ram can be then locked into position by the tap lOd on the fluid transfer link 9d and the pressurising means removed from the vents 22 and 23.
• this embodiment of the present invention is particularly useful in situations whereby it is desired to hold apart ( or together) objects and matter.
• this embodiment of the present invention could be used in preventing drains, mine tunnels and the like from collapsing.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Engineering & Computer Science (AREA)
• Actuator (AREA)
• Grinding Of Cylindrical And Plane Surfaces (AREA)
• Valve Device For Special Equipments (AREA)
• Seats For Vehicles (AREA)

Applications Claiming Priority (5)

Publications (2)

Family

ID=26651166

Family Applications (1)

Country Status (3)

Families Citing this family (5)

Citations (2)

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• 1994
  • 1994-03-09 EP EP94908527A patent/EP0688401A4/fr not_active Withdrawn
  • 1994-03-09 WO PCT/NZ1994/000017 patent/WO1994020760A1/fr not_active Application Discontinuation
  • 1994-03-09 AU AU61581/94A patent/AU6158194A/en not_active Abandoned

Patent Citations (2)

Non-Patent Citations (1)

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