Improvements in or relating to trigger valves for high-pressure fluid-operated devices

Abstract

an actuation trigger for a device, the actuation trigger comprising: a dosing chamber for holding a charge of high pressure actuating fluid received from a high pressure source; a dosing valve biased closed to seal the dosing chamber from an actuation chamber and retain the charge of the dosing chamber; a hammer actuated by a piston having a driven chamber on a first side of the piston and a trigger chamber on a second side of the piston sealed from the first side of the piston, the driven chamber receiving high pressure actuating fluid directly or indirectly from the high pressure source; and a hammer for selectively supplying high pressure actuating fluid to or releasing high pressure actuating fluid from the trigger chamber. and a trigger valve, wherein when the hammer has high pressure operating fluid in both the driven chamber and the trigger chamber, the hammer is held in a first position by a force imbalance, and when high pressure operating fluid is released from the trigger chamber, the hammer is driven towards the trigger chamber to or toward a second position, and when the hammer is driven to or toward the second position, it collides with the dosing valve, unseating the dosing valve and opening the dosing chamber and the actuating chamber, thereby allowing the charge to enter the actuating chamber and do work therein.

Description

[Technical Field]

[0001] The present invention relates to triggers and valves for high pressure fluid operated devices, and in particular, but not exclusively, to devices and methods for triggering and valving high pressure fluid operated devices, whether high pressure or low pressure, and for venting such devices. [Background technology]

[0002] Some pressure systems use fluids, such as air or another gas or liquid, at high or low pressure to drive a working load. The working load can be a reciprocating piston, a projectile being ejected, or pressure acting in pressure pulses on an object. In such applications, high-pressure fluid must be introduced into a region, such as a working chamber, where the working load will perform work. One method for introducing high-pressure fluid to the working load is through a valve that directly or indirectly isolates the working load from a reservoir and source of high-pressure fluid. The valve opens upon the action of an event, such as being triggered by an external signal. A quantity of high-pressure working fluid is transferred to the working load, and the valve closes again, allowing the high-pressure working fluid to perform work. For example, the high-pressure working fluid expands to drive the working load in the working chamber.

[0003] Prior art pneumatic trigger systems are not suitable for generating extremely short, instantaneous pressure pulses; they are typically valve systems that operate in a toggle on / off fashion. The on-to-off time frame is typically relatively long, which can be inefficient in terms of hydraulic fluid usage. This inefficiency results from the large amount of hydraulic fluid used due to slow opening and closing, especially when high pressures are considered. Furthermore, the subsequently introduced hydraulic fluid does not expand to efficiently produce work, typically not by a large factor, but simply fills and pushes the actuation cycle. This also means that the cycle rate of such prior art systems is relatively low.

[0004] Prior art systems that achieve high cycle rates are excessively complex and can suffer from premature wear and unstable cycle times.

[0005] Previous trigger systems have additional drawbacks. For example, conventional air-powered triggers (such as nail guns) are typically designed to be incorporated exclusively into "tethered" systems, meaning that the tool does not have an "on-board" pressure supply (they do not need to use hydraulic fluid efficiently because there is a relatively cheap, inexhaustible supply), e.g., the tool is tethered from a compressor.

[0006] Regulations and general safety design require a means to render portable pneumatic / mechanical systems safe and inert when not in use, during transport, and during repair. Conventional prior art accomplishes this by using separate valve systems, which introduces complexity, part count, and high cost. Furthermore, considering applications requiring high performance with light weight, portability, ergonomics, functional simplicity, and / or low manufacturing cost, incorporating additional parts and mechanisms to achieve a "safety" function is counter to these performance goals / criteria / philosophies.

[0007] Additionally, because such tethering systems must be capable of being disconnected from a separate air supply, it must be possible to safely depressurize and deactivate the system before disconnecting the pressure supply. These systems typically involve "back-purging" the pressurized chamber through the pressure supply tubing or piping. Such systems are not compatible with high thermodynamic efficiency designs that allow for untethered use. These purge valves must be built into the system itself.

[0008] Traditional trigger spool valve systems place the critical "switching" O-ring in the spool core, which is necessarily smaller in diameter than the spool bore within which it slides. This switching O-ring arrangement is unsuitable for high-pressure applications because the sealing / sliding diameter is defined by the minimum effective core diameter and seal thickness. This means the switching O-ring is too thin to switch high-pressure actuation fluid over long cycles. This is because the usable area of ​​the switching O-ring in the spool bore is small. The result is a small-area, thin switching O-ring, and a weaker switching O-ring.

[0009] In high-pressure applications, valve opening becomes complicated. The forces at play can be very large, and the time window for opening such valves is very small. This must all be done in a controlled, repeatable manner to provide a reliable and efficient system that does maximum work from a minimum volume of high-pressure working fluid.

[0010] Therefore, there is a need for reliable, robust and repeatable triggering systems for these systems.

[0011] There is also a need for the ability to vent pressure from behind the working load as it is moved or moved into position to do work or fire.

[0012] For example, and not by way of limitation, when the working chamber is a closed volume, the working load is a piston reciprocating within the working chamber. Even in highly efficient systems, where nearly all of the pressure of the working fluid is utilized to do work on the working load, e.g., when the piston is driven all the way to the far end of the working chamber, there may still be residual pressure behind the working load. This residual pressure may prevent or slow the working load, e.g., the piston, from returning to the working chamber to begin the next working cycle.

[0013] In another example, all of the pressure from the actuation fluid may be utilized, but the pressure increases when the actuation load returns. This can occur in a closed-volume actuation chamber with a piston, or when it has an open end and a projectile, for example, is front-loaded into the actuation chamber and forced into the actuation chamber. In examples where the actuation chamber may be open-ended, pressure must be relieved behind it when the actuation load, for example, a projectile, is inserted into the actuation chamber before being subjected to high-pressure fluid.

[0014] The need to vent pressure is to allow the actuating load to return to the ready state to the "inject" position or to allow the actuating load to be inserted into the actuating chamber with minimal resistance. In other words, the return or insertion of the actuating load creates increasing pressure because the volume occupied by the actuating fluid decreases as the actuating load moves to the ready position.

[0015] An example of a vent valve that reduces this "back pressure" is one that vents to atmosphere through an inlet valve when the port is opened, for example, by a member that uses the residual high-pressure fluid behind the working load to open the inlet valve, which retracts to its starting position. However, combining such an opening member with the need to open the exhaust port can require a higher load than desired in some cases because the opening member may be forced back against a spring or similar force that is strong enough to eject the opening member. In this application, the return of the working load may be prevented. In such an application, the exhaust port may be opened while the high-pressure fluid is still performing work on the working load. This results in a lower pressure than if the high pressure were vented to atmosphere or performing work on the working load. Again, while a simple solution, it creates complex sealing and manufacturing requirements, making the overall assembly compact.

[0016] Additional exhaust solutions are known that avoid some of the high forces and inefficiencies associated with opening the exhaust valve while the working fluid is still potentially acting on the working load, but these are mechanically complex, require multiple sealing elements, present manufacturing and assembly challenges, and are not an overall compact solution.

[0017] References herein to patent specifications, other external documents, or other sources of information are generally for the purpose of providing a context for discussing features of the invention. Unless specifically stated, the reference to such external documents or sources of information shall not be construed as an admission that such documents or such sources of information are prior art or form part of the general common knowledge in the art in any jurisdiction. Summary of the Invention [Problem to be solved by the invention]

[0018] It is an object of the present invention to provide an improved trigger valve for high pressure fluid engines or devices, or to provide a reliable and repeatable trigger valve for high pressure fluid engines, or to overcome the above-mentioned drawbacks and solve the above-mentioned needs, or at least provide the public with a useful choice. [Means for solving the problem]

[0019] In a first aspect, the present invention provides an actuation trigger for a device, comprising: a dosing chamber for holding a charge of high pressure actuation fluid received from a high pressure source; a dosing valve biased to a closed state to seal the dosing chamber from the actuation chamber and to retain a charge in the dosing chamber; a piston-actuated hammer having a driven chamber on a first side of the piston and a trigger chamber on a second side of the piston, the trigger chamber sealed from the first side, the driven chamber receiving high pressure actuation fluid from a high pressure source; a trigger valve for selectively supplying high pressure actuating fluid to or releasing high pressure actuating fluid from the trigger chamber; When the hammer has high pressure hydraulic fluid in both the driven chamber and the trigger chamber, the hammer is held in a first position by a force imbalance, and when the high pressure hydraulic fluid is released from the trigger chamber, the hammer is driven into or toward the trigger chamber in a second position; When the hammer is driven to or toward the second position, it strikes the dosing valve, unseating it and opening the seal between the dosing chamber and the actuation chamber, thereby allowing the charge to enter the actuation chamber and do work.

[0020] Preferably, the force imbalance results from a greater working area of ​​high pressure actuating fluid on the trigger chamber side of the piston than on the driven chamber side of the piston.

[0021] Preferably, the trigger valve is a sliding spool valve.

[0022] Preferably, when the dosing valve is open from the dosing chamber to the actuation chamber, there is no supply from the high pressure source to the dosing chamber, whether via the trigger valve or otherwise.

[0023] Preferably, the trigger valve (having at least two positions) acts to selectively release high pressure actuating fluid from either the dosing chamber, the driven chamber, or the trigger chamber ("actuating chamber") to the ambient, or to supply high pressure actuating fluid from a high pressure source directly or indirectly to either the dosing chamber, the driven chamber, or the trigger chamber ("actuating chamber"), in order to trigger the device: A first valve position in which the high pressure source directly or indirectly supplies the actuation chamber and prepares it for actuation, the trigger valve being: Opening the supply to the dosing chamber and closing the vent path therefrom; providing for opening the supply to the dosing chamber and the trigger chamber and for actuating or not actuating the opening of the dosing valve; a second valve position for actuating the device and closing off the supply from the high pressure source, the trigger valve comprising: shutting off the supply to the device, particularly to the dosing chamber and trigger chamber; The trigger chamber is vented to the ambient environment.

[0024] Preferably, the trigger valve has a third valve position for making the device safe, the trigger valve comprising: Shut off the supply to the dosing chamber, Venting the dosing chamber to the ambient environment; Optionally, one or more of the remaining working chambers are vented.

[0025] Preferably, when the trigger valve closes the supply to the device, it prevents high pressure actuation fluid from exiting the high pressure source.

[0026] Preferably, the trigger chamber, when delivered, is filled before the dose chamber.

[0027] Preferably, the hammer slides along a first sliding axis and the dosing valve slides along a second sliding axis.

[0028] Preferably, the first and second sliding axes are at least parallel, and preferably concentric.

[0029] Preferably, the dosing valve is an annular ring having an annular ring sealing surface for sealing the dosing chamber from the actuation chamber.

[0030] Preferably, the dosing valve is spring biased in the closed position.

[0031] Preferably, the hammer has a resilient element on the first and / or second side to promote or retard the force imbalance.

[0032] Preferably, the hammer is returned to or towards the first position at least in part by the return of high pressure actuation fluid to the dosing valve or trigger chamber.

[0033] Preferably, the hammer is acted upon by pressure in the actuation chamber to retard continued movement towards the dosing valve.

[0034] Preferably, the operating load is: a restraint within the working chamber, such as a piston or similar; or It may be an unconfined body emanating from the actuation chamber, such as a projectile or the like, or it may be a pressure wave operating within the actuation chamber.

[0035] Preferably, the high pressure working fluid is a compressible or incompressible fluid.

[0036] Preferably, the high pressure working fluid is in the range of 15 bar to 100 bar.

[0037] Preferably, the fluid is a gas.

[0038] Preferably, the actuation load is a constrained body within the actuation chamber, such as a piston or similar, or an unconstrained body ejected from the actuation chamber, such as a projectile or similar, or a pressure wave acting within the actuation chamber.

[0039] Preferably, there is a drain valve; On, in, or from the working chamber, from a first end of the working chamber to or toward an opposite second end of the working chamber, Back a high pressure hydraulic fluid acting on the receiving fluid pressure into the return chamber from a front or region of the working load, the fluid pressure being at least partially generated by the working load moving toward the second end of the working chamber; The discharge valve is adapted to allow fluid pressure in the return chamber to act on an operating surface of the discharge valve to open the discharge valve, and when opened, Back to allow high pressure working fluid in the working chamber at This allows the front and Back A pressure difference is created between the second end and the first end, causing the working load to move from the second end to or back toward the first end.

[0040] Preferably, the exhaust valve exhausts the working fluid substantially non-parallel to a longitudinal axis extending between the first and second ends and at an angle non-parallel to the longitudinal axis.

[0041] Preferably, the discharge from the working chamber is at or near a right angle to the longitudinal axis.

[0042] Preferably, the exhaust valve at least partially defines a exhaust chamber along a flow path from the sidewall through the exhaust valve before being exhausted to low or ambient pressure.

[0043] Preferably, the pressure areas (front and rear) of the discharge chamber are different from each other to allow for the release of force on the discharge valve based on the pressure within the discharge chamber.

[0044] Preferably, a net force acts on the discharge valve to overcome or increase the closed biasing means, the net force being: Back and / or a second side of the exhaust valve in fluid communication with the front surface.

[0045] Preferably, the net force is time-varying.

[0046] Preferably, the discharge valve slides parallel to the longitudinal axis.

[0047] Preferably, the pressure area of ​​the discharge chamber is at least partially provided by sealing before, after and at the inner and outer diameters of the discharge valve.

[0048] Preferably, when actuation fluid flows from the actuation chamber into the discharge chamber, pressure in the discharge chamber holds the discharge valve open.

[0049] Preferably, one or more fluid connection ports connecting the actuation chamber to the discharge chamber, or the sum of these ports, are not of the same size or flow rate as the discharge from the discharge chamber to low or ambient pressure, thereby causing different flows into and out of the discharge chamber.

[0050] Preferably, the low pressure is atmospheric pressure or the ambient environment of the device.

[0051] Preferably, a check valve is provided leading from the low pressure to the return chamber.

[0052] Preferably, the check valve opens if there is a pressure imbalance between before the working load and after the working load when the discharge valve opens.

[0053] Preferably, the check valve is arranged in the discharge valve between the discharge chamber and the return chamber.

[0054] Preferably, the check valve is provided by an O-ring, X-ring, lip seal, or other continuous or variable cross-section sealing element that prevents flow from the return chamber to the discharge chamber but allows flow from the discharge chamber to the return chamber.

[0055] Preferably, the check valve opens when the pressure in the discharge chamber exceeds the pressure in the return chamber, allowing the pressure in the discharge chamber to recirculate and act on the front of the working load, helping to drive it towards the first end.

[0056] Preferably, the return chamber is located in the ambient environment outside the working chamber.

[0057] Preferably, the exhaust valve is provided at or towards the first end.

[0058] Preferably, the exhaust valve is an annular ring that is movable along a longitudinal axis extending from the first end to the second end.

[0059] Preferably, the longitudinal axis is the main axis of the working chamber.

[0060] Preferably, the annular ring is located outside the working chamber.

[0061] Preferably, the return chamber receives high pressure actuating fluid from the actuating chamber via at least one actuating fluid connection.

[0062] Preferably, a first of the at least one fluid connection is provided at or towards the second end of the working chamber.

[0063] Preferably, a second of the at least one fluid connection is provided between the first end and the first fluid connection.

[0064] Preferably, the second fluid connection includes a one-way valve from the working chamber to the return chamber.

[0065] Preferably, a baffle is provided in the return chamber between the working face of the discharge valve and the reception of fluid from the working chamber.

[0066] Preferably, the baffle is provided with one or more holes to slow the development of pressure towards the working surface compared to the development of pressure on the opposite side of the baffle.

[0067] In another aspect of the invention, the invention provides a high pressure fluid actuation system comprising: 、 high comprising or including a dosing chamber holding a charge of hydraulic fluid, the dosing chamber in fluid communication with a first side of a piston operatively connected to the hammer and in selective fluid communication with a second side of the piston; When high pressure hydraulic fluid is supplied to both the first and second sides, the piston experiences a force imbalance in the first position, The piston experiences a force imbalance when actuated by selectively removing high pressure actuating fluid from a second side of the piston and urging it to move to or toward a second position.

[0068] Preferably, the hammer is held in the first position by a force imbalance from equal pressures between the trigger chamber and the driven chamber, the pressure areas of the trigger chamber and the driven chamber being different, resulting in a net greater force towards the first position.

[0069] Preferably, either or both of the first and second sides are provided with elastic elements.

[0070] Preferably, the high pressure working fluid is a compressed fluid.

[0071] Preferably, the high pressure working fluid is in the range of 15 bar to 90 bar.

[0072] Preferably, the fluid is a gas.

[0073] Preferably, when the dosing valve is open from the dosing chamber to the actuation chamber, there is no supply from the high pressure source to the dosing chamber, whether via the trigger valve or otherwise.

[0074] Preferably, the apparatus includes a drain valve; a working load from a first end of the working chamber to or toward an opposite second end of the working chamber by an actuating chamber or actuatable working chamber that can selectively receive some or all of the charge of high pressure working fluid from the dosing chamber; Back a working load driven using a high pressure working fluid acting on the fluid pressure received in the return chamber from a front face of the working load, the fluid pressure being generated at least in part as a result of the working load moving down the working chamber towards the second end; The discharge valve is adapted to allow fluid pressure in the return chamber to act on an operating surface of the discharge valve to open the discharge valve, and when opened, Back the high-pressure working fluid in the working chamber at the position at the lower pressure is discharged from the working chamber to the lower pressure position, and the high-pressure working fluid flows out through the side wall of the working chamber to the discharge valve; This creates a pressure differential between the front and rear surfaces, causing the actuation load to move from the second end back to or towards the first end.

[0075] In another aspect of the invention, the invention provides an actuation trigger for a device, comprising: a dosing chamber holding a charge of high pressure actuation fluid received from a high pressure source; a dosing valve biased to a closed condition to seal the dosing chamber from the actuation chamber, to retain a charge in the dosing chamber, and capable of opening under controlled operation to admit the charge to the actuation chamber; a trigger valve that selectively supplies high-pressure working fluid from a high-pressure source to the dosing chamber and directly or indirectly controls the opening and closing of the dosing valve; When the dosing valve is open from the dosing chamber to the actuation chamber, there is no supply from the high pressure source to the dosing chamber, whether via the trigger valve or otherwise.

[0076] Preferably, the sliding spool valve comprises: a trigger valve having a first valve position that directly or indirectly supplies a high pressure source to the dosing chamber and arms the dosing chamber; Opening the supply to the dosing chamber and closing the vent path therefrom; Provision is made to open the supply to other actuation chambers and not actuate the opening of the dosing valves; a trigger valve having a second valve position for actuating the device and closing off the supply from the high pressure source; closing off the supply to the device, in particular to the administration chamber; Another actuation chamber allows actuation of the opening of the dosing valve.

[0077] Preferably, the trigger valve has a third valve position for making the device safe, the trigger valve comprising: Shut off the supply to the dosing chamber, Ventilate other operating rooms.

[0078] Preferably, the exhaust valve comprises: Within the working chamber, the working load is transferred from a first end of the working chamber to or toward a second end opposite the working chamber. Back a working load driven using a high pressure working fluid acting on the receiving fluid pressure from a front face of the working load into the return chamber, the fluid pressure being at least partially created by the working load moving toward the second end of the working chamber; The discharge valve is adapted to allow fluid pressure in the return chamber to act on an operating surface of the discharge valve to open the discharge valve, and when opened, Back The high pressure working fluid in the working chamber is released from the working chamber to a low pressure position, and the high pressure working fluid flows out through the side wall of the working chamber to the discharge valve; This allows the front and Back A pressure difference is created between the second end and the first end, causing the working load to move from the second end to or back toward the first end.

[0079] In another aspect of the invention, the invention provides an actuation trigger for a device, comprising: 1. A trigger valve for selectively controlling the supply of high pressure hydraulic fluid from a high pressure source to one or more operating chambers to control actuating chambers, the actuating chambers using a charge of high pressure hydraulic fluid acting on a working load, the trigger valve comprising: a first valve position for supplying one or more operating chambers to an actuation ready state directly or indirectly from a high pressure source, the trigger valve comprising: Opening up supply to one or more operating rooms, Preparing the working chamber to prevent it from operating and closing the vent to ambient pressure; a trigger valve having or including a second valve position for actuating the device; Opening and closing the supply to one or more working chambers, allowing the chambers to be loaded and worked; a third valve position for making the device safe, the trigger valve being shutting off the supply to one or more operating rooms; Vent one or more working chambers to ambient pressure, rendering the equipment inoperable or inactive.

[0080] Preferably, the trigger valve is any one or more of a rotary valve (ball or otherwise), a sliding spool valve, a two or more way directional control valve, or any combination thereof.

[0081] Preferably, one or more operating chambers control a charge valve to deliver a charge to the actuation chamber.

[0082] Preferably, there is a drain valve; of the working load from within or from the working chamber to or towards the opposite second end of the working chamber. Back or a region using a high pressure working fluid acting on the working load; receiving fluid pressure into the return chamber from a region in front of the working load, the fluid pressure being at least partially generated by the working load moving toward the second end of the working chamber; The discharge valve is adapted to allow fluid pressure in the return chamber to act on an operating surface of the discharge valve to open the discharge valve, and when opened, Backthe high-pressure working fluid in the working chamber at the position at the lower pressure is discharged from the working chamber to the lower pressure position, and the high-pressure working fluid flows out through the side wall of the working chamber to the discharge valve; This allows the front and Back A pressure difference is created between the second end and the first end, causing the working load to move from the second end to or back toward the first end.

[0083] Preferably, there is no direct path from the high pressure source to the actuation chamber regardless of the position of the trigger valve.

[0084] In yet another aspect, the present invention provides an apparatus, comprising: a dosing chamber holding a charge of high pressure actuation fluid received from a high pressure source; a dosing valve biased to a closed state to seal the dosing chamber from the actuation chamber and retain a charge in the dosing chamber; a hammer actuated by a piston having a driven chamber on a first side of the piston and a trigger chamber on a second side of the piston sealed from the first side, the driven chamber receiving high pressure actuation fluid directly or indirectly from a high pressure source; a trigger valve for selectively supplying high pressure actuating fluid to or releasing high pressure actuating fluid from the trigger chamber; a trigger valve for selectively supplying high pressure actuating fluid to or releasing high pressure actuating fluid from the trigger chamber; When the hammer has high pressure hydraulic fluid in both the driven chamber and the trigger chamber, the hammer is held in a first position by a force imbalance, and when the high pressure hydraulic fluid is released from the trigger chamber, the hammer is driven into or towards the trigger chamber to a second position; When the hammer is driven to or toward the second position, it strikes the dosing valve, releasing the dosing valve and opening the seal between the dosing chamber and the actuation chamber, thereby allowing the charge to enter the actuation chamber and be actuated.

[0085] Preferably, the force imbalance results from a greater working area of ​​high pressure actuating fluid on the trigger chamber side of the piston than on the driven chamber side of the piston.

[0086] Preferably, the trigger valve is a sliding spool valve.

[0087] Preferably, the trigger valve (having at least two positions) acts to selectively release high pressure actuating fluid into the environment or to supply high pressure actuating fluid from a high pressure source directly or indirectly to either the dosing chamber, the driven chamber, or the trigger chamber ("actuating chamber") to trigger the device: A first valve position in which the high pressure source directly or indirectly supplies the actuation chamber and prepares it for actuation, the trigger valve being: Opening the supply to the driven and trigger chambers; Close the airway from the administration chamber. providing for opening the supply to the dosing chamber and the trigger chamber and not actuating the opening of the dosing valve; a second valve position for actuating the device and closing off the supply from the high pressure source, the trigger valve comprising: shutting off the supply to the device, particularly to the dosing chamber and trigger chamber; The trigger chamber is vented to the ambient environment.

[0088] Preferably, the trigger valve has a third valve position for making the device safe, the trigger valve comprising: Shut off and close off the supply to the administration and trigger chambers; Vent the dosing chamber, Vent the trigger chamber.

[0089] Preferably, when the trigger valve closes the supply to the device, it prevents high pressure actuation fluid from exiting the high pressure source.

[0090] Preferably, the trigger chamber, when supplied, fills before the dosing chamber.

[0091] Preferably, the hammer slides along a first sliding axis and the dosing valve slides along a second sliding axis.

[0092] Preferably, the first and second sliding axes are at least parallel, and preferably concentric.

[0093] Preferably, the dosing valve is an annular ring having an annular ring sealing surface for sealing the dosing chamber from the actuation chamber.

[0094] Preferably, the dosing valve is spring biased in the closed position.

[0095] Preferably, the hammer has a resilient element on the first and / or second side to promote or retard the force imbalance.

[0096] Preferably, the hammer is returned to or towards the first position at least in part by the return of high pressure actuation fluid to the dosing valve or trigger chamber.

[0097] Preferably, the actuation acts on the following loads: a restraint within the working chamber, such as a piston or similar; or It may be an unconfined body emanating from the actuation chamber, such as a projectile or the like, or it may be a pressure wave operating within the actuation chamber.

[0098] Preferably, the high pressure working fluid is a compressible or incompressible fluid.

[0099] Preferably, the high pressure working fluid is in the range of 15 bar to 90 bar.

[0100] Preferably, the fluid is a gas.

[0101] Preferably, there is a drain valve; a first end of the actuating chamber to or toward an opposite second end of the actuating chamber by an actuating chamber on, within, or operable to selectively receive some or all of the charge of high pressure actuating fluid from a dosing chamber; Back a working load driven using a high pressure working fluid acting on the fluid pressure received in the return chamber from a front face of the working load, the fluid pressure being generated at least in part as a result of the working load moving down the working chamber towards the second end; The fluid pressure in the return chamber acts on the working surface of the discharge valve, and the discharge valve is adapted to open the discharge valve, allowing the high-pressure working fluid in the working chamber at the back side to be discharged from the working chamber to the low-pressure location when opened, and the high-pressure working fluid flows out to the discharge valve through the side wall of the working chamber; This allows the front and Back A pressure difference is created between the second end and the first end, causing the working load to move from the second end to or back toward the first end.

[0102] In another aspect, the present invention provides a method of operating an apparatus, comprising: charging the dosing chamber with a charge of high pressure actuation fluid; charging a driven chamber on a first side of the hammer with high pressure hydraulic fluid; and charging a trigger chamber on the second side of the hammer with high pressure hydraulic fluid; the first and second sides being separated by a piston operatively connected to the hammer such that the hammer maintains force balance in the first position; releasing the high pressure flow actuator from the trigger chamber to drive the hammer to or toward the second position; and operating the dosing valve by impacting the hammer when the dosing valve is in the second position or moving towards the second position, to cause the dosing valve to exit from a sealed position in which the dosing valve seals the dosing chamber from the actuation chamber to an open position in which the charge enters and actuates the actuation chamber.

[0103] Preferably, the force imbalance is at least partly provided or retarded by a biasing means such as a spring.

[0104] Preferably, the hammer is returned at least in part to or towards the first position by return of high pressure actuation fluid to the dosing valve or trigger chamber acting on a portion of the hammer.

[0105] Preferably, the high pressure actuation fluid is supplied directly or indirectly from a high pressure source.

[0106] Preferably, the method includes the step of charging the driven chamber directly or indirectly from a high pressure source.

[0107] Preferably, the method includes the step of selectively arming the trigger chamber and the dose chamber or releasing the trigger chamber and / or the dose chamber via a trigger valve.

[0108] Preferably, the trigger valve is a sliding spool valve.

[0109] Preferably, the trigger valve (having at least two positions) acts to selectively release high pressure actuating fluid into the environment or to supply high pressure actuating fluid from a high pressure source directly or indirectly to either the dosing chamber, the driven chamber, or the trigger chamber ("actuating chamber") to trigger the device: A first valve position in which the high pressure source directly or indirectly supplies the actuation chamber and prepares it for actuation, the trigger valve being: Opening the supply to the dosing chamber and closing the vent path therefrom; Provision is made to open the supply to other chambers and not actuate the opening of the dosing valves; a second valve position for actuating the device and closing off the supply from the high pressure source, the trigger valve comprising: shutting off the supply to the device, particularly to the dosing chamber and trigger chamber; The actuation chamber allows actuation of the opening of the dosing valve. Preferably, the trigger valve has a third valve position for safeguarding the device, said trigger valve comprising: Shut off the supply to the dosing chamber, Ventilate other operating rooms.

[0110] Preferably, the method is such that when the dosing valve is opening from the dosing chamber to the actuation chamber, there is no supply from the high pressure source to the dosing chamber, whether via the trigger valve or otherwise.

[0111] Preferably, the method includes providing a drain valve; a first end of the actuating chamber to or toward an opposite second end of the actuating chamber by means of a pressure chamber that can selectively receive some or all of the charge of high pressure actuating fluid from the dosing chamber; Back driving a working load using a high pressure working fluid acting on the receiving fluid pressure from a front side of the working load into the return chamber, the fluid pressure being generated at least in part as a result of the working load moving down the working chamber toward the second end; the fluid pressure in the return chamber acts on an operating surface of the exhaust valve to open the exhaust valve, which, when opened, allows high pressure working fluid in the working chamber at the back to be discharged from the working chamber to a low pressure location, and the high pressure working fluid flows out through a side wall of the working chamber to the exhaust valve; This allows the front and Back A pressure difference is created between the second end and the first end, causing the working load to move from the second end to or back toward the first end.

[0112] Preferably, the exhaust valve exhausts the working fluid substantially non-parallel to a longitudinal axis extending between the first and second ends and at an angle non-parallel to the longitudinal axis.

[0113] Preferably, the discharge from the working chamber is at or near a right angle to the longitudinal axis.

[0114] Preferably, the exhaust valve at least partially defines a exhaust chamber along a flow path from the side wall through the exhaust valve before being exhausted to low pressure.

[0115] Preferably, the pressure areas (front and rear) of the discharge chamber are different from each other to allow for the release of force on the discharge valve based on the pressure within the discharge chamber.

[0116] Preferably, a net force acts on the discharge valve to overcome or increase the closed biasing means, the net force being: Backand / or a second side of the exhaust valve in fluid communication with the front surface.

[0117] Preferably, the net force is time-varying.

[0118] Preferably, the discharge valve slides parallel to the longitudinal axis.

[0119] Preferably, the pressure area of ​​the discharge chamber is at least partially provided by sealing before, after and at the inner and outer diameters of the discharge valve.

[0120] Preferably, when fluid pressure flows from the actuation chamber into the discharge chamber, pressure in the discharge chamber holds the discharge valve open.

[0121] Preferably, one or more fluid connection ports connecting the actuation chamber to the discharge chamber, or the sum of these ports, are not of the same size or flow rate as the discharge from the discharge chamber to low or ambient pressure, thereby causing different flows into and out of the discharge chamber.

[0122] Preferably, the low pressure is atmospheric pressure or the ambient environment of the device. Preferably, a check valve is provided leading from the low pressure to the return chamber. Preferably, the check valve opens if there is a pressure imbalance between before the working load and after the working load when the discharge valve opens. Preferably, the check valve is arranged in the discharge valve between the discharge chamber and the return chamber. Preferably, the check valve is provided by an O-ring, X-ring, lip seal, or other continuous or variable cross-section sealing element that prevents flow from the return chamber to the discharge chamber but allows flow from the discharge chamber to the return chamber. Preferably, the check valve opens when the pressure in the discharge chamber exceeds the pressure in the return chamber, allowing the pressure in the discharge chamber to recirculate and act on the front of the working load, helping to drive it towards the first end.

[0123] Preferably, the return chamber is located in the ambient environment outside the working chamber. Preferably, the actuation load is a constrained body within the actuation chamber, such as, but not limited to, a piston, or an unconstrained body ejected from the actuation chamber, such as, but not limited to, a projectile, or a pressure wave acting within the actuation chamber.

[0124] Preferably, the exhaust valve is provided at or towards the first end.

[0125] Preferably, the exhaust valve is an annular ring that is movable along a longitudinal axis extending from the first end to the second end.

[0126] Preferably, the longitudinal axis is the main axis of the working chamber.

[0127] Preferably, the annular ring is located outside the working chamber.

[0128] Preferably, the return chamber receives high pressure actuating fluid from the actuating chamber via at least one actuating fluid connection.

[0129] Preferably, a first of the at least one fluid connection is provided at or towards the second end of the working chamber.

[0130] Preferably, a second of the at least one fluid connection is provided between the first end and the first fluid connection.

[0131] Preferably, the second fluid connection includes a one-way valve from the working chamber to the return chamber.

[0132] Preferably, a baffle is provided in the return chamber between the working face of the discharge valve and the reception of fluid from the working chamber.

[0133] Preferably, the baffle is provided with one or more holes to slow the development of pressure towards the working surface compared to the development of pressure on the opposite side of the baffle.

[0134] In another aspect, the invention resides in an actuation trigger for a device as herein described with reference to at least one of the accompanying drawings.

[0135] In another aspect, the invention resides in a high pressure working fluid actuation system as herein described with reference to at least one of the accompanying drawings.

[0136] In another aspect, the invention resides in an apparatus as herein described with reference to at least one of the accompanying drawings.

[0137] In another aspect, the invention resides in a method of operating an apparatus as herein described with reference to at least one of the accompanying drawings.

[0138] As used herein, the term "and / or" means "and," "or," or both.

[0139] As used herein, the suffix "(s)" on the end of a noun refers to the plural, the singular, and the singular-plural form of the noun.

[0140] As used herein, the word "have (gerund)" means "consisting of at least a portion of." When interpreting descriptions herein that include this word, all features initiated by the word in each description must be present, although other features may also be indicated. Related words such as "have (base form)" and "have (past participle)" should be interpreted in a similar manner.

[0141] Reference to a range of numbers disclosed herein (e.g., 1-10) is intended to incorporate reference to all rational numbers within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, 10) and to any range of rational numbers within that range (e.g., 2-8, 1.5-5.5, 3.1-4.7).

[0142] The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference.

[0143] The present invention may also be generally stated to consist in the parts, elements and features referred to or indicated individually or collectively in the specification of this application, and any and all combinations of two or more of those parts, elements and features, and where reference is made herein to a particular integer that has a known equivalent in the art to which the invention pertains, such known equivalent is also deemed to be incorporated herein as if set forth individually.

[0144] Other aspects of the invention will become apparent from a reading of the following description, given by way of example only, and with reference to the accompanying drawings, in which:

[0145] Next, preferred embodiments of the present invention will be described with reference to the following drawings. [Brief explanation of the drawings]

[0146] [Figure 1] FIG. 1 is a vertical cross-sectional view of a high-pressure hydraulic fluid operated device including a discharge valve embodying the present invention, shown with the discharge valve closed and a working load able to operate to or towards a first end. [Figure 2] FIG. 2 is a cross-sectional view similar to that of FIG. 1, showing the working load being transferred to the working chamber by the action of the working fluid, with the resulting pressure forcing the exhaust valve open. [Figure 3] FIG. 3(A) is a view similar to FIG. 1 showing details of the check valve in the return chamber, reducing the pressure difference across the working load and allowing a good return stroke of the working load in the ready state when the check valve is closed; FIG. 3(B) shows the working load just beginning to move through the working chamber with the check valve closed; FIG. 3(C) shows the working load returning to the chamber and the check valve opening when there is a pressure difference across the working load; and FIG. 3(D) is an isometric view of a reed valve performing the function of a check valve. [Figure 4]FIG. 4 is a similar view of a vertical cross section along the longitudinal axis of an air engine of the present invention having a trigger valve and another variation of an exhaust valve incorporating a check valve, with the air engine in an armed state, the exhaust valve in a closed state, and an operating load ready to be applied. [Figure 5] FIG. 5 is a view similar to FIG. 4, showing the trigger valve actuated to the second valve position to release the hammer, impacting the dosing valve and charging the actuating valve, the actuating load being sent to the actuating chamber towards the second end, the discharge valve being opened by the action of the pressure in the return chamber, allowing the pressure behind the actuating load to be discharged to atmospheric pressure, and the discharge port from the side of the actuating chamber being clearly shown. [Figure 6] FIG. 6 is a view similar to FIG. 5 showing the hammer and piston ready to return to their pre-impact positions and the working load returning to the working chamber. [Figure 7] FIG. 7 is a view similar to FIG. 6, showing the one-way check valve in the discharge valve open to allow recirculation to the return chamber. [Figure 8] FIG. 8 is an enlarged schematic diagram of the trigger valve of FIG. 4, showing the trigger valve in the ready to trigger or first valve position and the trigger valve train pressurized with hydraulic fluid from a high pressure source. [Figure 9] FIG. 9 is an enlarged schematic diagram of the trigger valve of FIG. 4 in the ready or first valve position, showing the trigger / ejection chamber primed and holding the hammer via the hammer piston, and the trigger valve train supplied with high pressure actuation fluid from the dosing chamber and high pressure source to the ejection chamber. [Figure 10] FIG. 10 is an enlarged view of the trigger valve of FIG. 5, showing the trigger valve in the second valve position, with the valve train open to release high-pressure actuation fluid from the discharge / trigger chamber, and thus the pressure in the drive chamber drives the hammer to impact and open the dosing valve and charge the actuation chamber (the actuation load has already moved down the actuation chamber under the action of the charging pressure fluid). [Figure 11]FIG. 11 shows an enlarged cross-sectional view of a further variation of a trigger valve configuration for controlling the release of the release chamber at (A) the sealing element of the trigger valve piston, (B) the vent from the spool bore for the trigger valve piston, and (C) the supply from the dosing chamber to the release chamber via a transfer port. [Figure 12] Figure 12 is a view similar to Figure 8, in which the trigger valve has a third valve position to safeguard the device, allowing high pressure hydraulic fluid in the dosing chamber to be vented to the environment, and optionally to the trigger chamber and driven chamber, preventing the hammer from firing into the dosing valve. DETAILED DESCRIPTION OF THE INVENTION

[0147] Next, a preferred embodiment of the present invention will be described with reference to FIGS.

[0148] A device 1 that operates with high pressure hydraulic fluid is illustrated in Figure 1 and more particularly in Figure 4, the example shown is from a nail gun or fastening gun, however, the configuration can be used in any device that utilizes high pressure hydraulic fluid (also referred to interchangeably herein as high pressure fluid) to perform work.

[0149] It should be understood that the high pressure working fluid may be a highly compressed gas, liquid, or similar working substance flowing under high pressure. In a preferred embodiment of the present invention, the high pressure working fluid is non-flammable in the operating range of the fluid to which the present invention is applied.

[0150] The apparatus 1 comprises a working load 4 received in a working chamber 3, a portion of which is defined by a side wall 31. In this example, the working chamber has a constant cross-section and is cylindrical, including the side wall 31. However, the working chamber 3 may have a cross-section different from circular and may adopt any desired shape, such as, but not limited to, elliptical, rectangular, or other shapes. In most cases, the working chamber has a constant cross-section along its length. However, in some special applications, the cross-section of the working chamber may vary, and the working load may adapt to such changes in cross-section.

[0151] The actuation load 4 may be a piston as shown, such as used in fastening guns, e.g., for nails, or in pest control traps, i.e., of the trapped type, or the actuation load 4 may be of the non-trapped type, such as a projectile or the like ejected from the actuation chamber 3, or a pressure wave utilized in another manner.

[0152] In the illustrated example, the actuation load 4 is a piston 22 that supports a striker or anvil 43. The striker or anvil 43 acts on a fastener, such as a nail, as the actuation load 4 moves. Alternatively, the striker may be of a different form to achieve a different result, for example, it may be flat or shaped in other shapes to release energy into organic or inorganic matter, thereby eliminating pests or the like.

[0153] In other forms, the device may expel a charge of high-pressure working fluid into or from a working chamber to produce work. This work may be a pressure wave from the device to affect a real object as a working load in the working chamber, whether captured as a reciprocating piston or moved or expelled therefrom as a projectile. Alternatively, work may be a pressure wave sent from the working chamber or from the device to affect something external to the device.

[0154] The working chamber 3 and the device 1 have a first end 5 and a second end 8, and the working load 4 is Back9 and a front surface 7. The actuation load 4 moves from a first end 5 to a second end 8 upon actuation.

[0155] As shown, a return chamber 10 is provided. In a preferred form, as shown, the return chamber 10 is annular and surrounds the working chamber 3. In this configuration, the outside, or outer surface, of the side wall 31 defines a portion of the return chamber 10, as shown in FIG. 2, for example. However, the return chamber 10 may take other forms, surround only a portion of the working chamber 3, be not defined by a side wall, or be separated from the side wall. For example, although not shown, the return chamber may be a separate volume and fluidly attached to the working chamber by a conduit, whether flexible or not.

[0156] The return chamber 10 is in fluid communication with the working chamber 4, at least from the vicinity of the second end 8. In the example shown, two fluid communication passages are provided: a first fluid communication passage 17 adjacent to or towards the second end 8, and a second fluid communication passage 18 between the second end 8 and the first end 5.

[0157] As shown in FIG. 1 , the working surface 28 of the discharge valve 2 is fluidly connected to the return chamber 10. A valve member 37, such as an O-ring 34 shown in FIG. 2 , forms part of the working surface 28. In the illustrated example, the discharge valve 2 is annular and can slide and be biased along a valve sliding axis (in this example, the longitudinal axis 15 of the device). The longitudinal axis in this case is an axis parallel to the line of movement, i.e., the sliding axis of the actuation load. In the illustrated embodiment, the longitudinal axis may also be the central main axis of the actuation chamber. The working surface 28 is a surface having a surface perpendicular to the valve sliding axis (in this example, the longitudinal axis 15) and is a surface on which pressure acts to produce a resultant force in the direction of the valve sliding axis of the discharge valve. In other words, working surfaces (sometimes called effective surfaces or effective areas) are surfaces that lie in a plane perpendicular to the sliding axis of the component they act on, such as a valve or piston.

[0158] However, in other embodiments, the exhaust valve 2 need not be an annular ring, but may be fluidly coupled to perform the function of the exhaust valve as described. For example, the exhaust valve may be fluidly coupled as described above to perform the same function, but may not be physically fluidly coupled to the main body, and may be a spool valve or the like.

[0159] The discharge valve 2 is normally biased in a closed position by a biasing means 29, such as a spring, as shown in Figure 1. In the closed position 11, as shown in Figure 1, the discharge valve 2 closes an outlet 30 in a side wall 31 of the working chamber 3. Thus, in this and other embodiments, the outlet or discharge from the working chamber 3 passes through the side wall at or near a right angle to the longitudinal axis of the device 1, or at least not parallel to the longitudinal axis.

[0160] In the illustrated embodiment, and preferably all embodiments, the exhaust valve 2 receives the exhaust through the side wall 31 of the working chamber 3, which preferably exits the side of the device 1 via an exhaust port 32. However, in other configurations, the exhaust may exit through another area of ​​the device, or at least through the side wall of the working chamber.

[0161] In a further variation (not shown), the exhaust port may be parallel to the hammer but offset from the central axis through rear wall 77. Such a variation may use a spool valve (similar to that of a trigger valve) rather than the annular ring style exhaust valve described above.

[0162] However, the exhaust valve 2 could also be a separate valve device actuated from the return chamber 10. For example, although not shown, the exhaust valve could be a separate annular piston valve or other type of valve, such as a spool valve acting parallel to or at an angle to the working chamber 3 or the return chamber 10. Similarly, although the return chamber is shown as an annular chamber around the working chamber, it could be a separate volume connected to the exhaust valve, as discussed above. Such an arrangement could be desirable for a number of reasons, including but not limited to, where the arrangement does not need to be compact, i.e., not hindered by space limitations.

[0163] When the discharge valve 2 is in the open position 12 as shown in Figure 2, it slides to the left compared to the position of the discharge valve 2 in Figure 1, providing an outlet or flow path (even if depressurized after work has been performed) from the working chamber 3 through the outlet 30, through the discharge valve port 33, and to the discharge port 32, as shown by the arrow. In a preferred form, the discharge port 32 is at low pressure, for example, to the atmosphere or ambient environment 14. The discharge port 32 as shown is a hole in the housing 36 of the device 1.

[0164] In some cases, when the actuation load moves to the first end 5 to the ready position or back, Back The front 7 may have a lower pressure than the 9, Back 9. This is particularly true when the working load is moving at high speeds and the dynamic action of the working fluid is required to equalize pressure or avoid leaks that occur at slow speeds. This front pressure may be the same fluid as the high pressure working fluid, or it may be a different fluid. For example, the high pressure working fluid may be compressed carbon dioxide and the front fluid may be an ambient fluid such as air.

[0165] This pressure difference, or balance, resists movement of the working load 4 towards the first end 5 because as the working load 4 returns to the first end 5, the working fluid is trapped there and compressed by the movement of the working load 4. Because the return chamber 10 and front face 7 are normally closed volumes, the consistency, or at least the speed of return, to the ready position at the first end 5 is reduced, and returning the working load entirely may even be avoided.

[0166] In such an example, a one-way or check valve 23, such as a reed valve 24, may be provided as shown in Figures 3(A)-3(D). The reed valve is an elastic ring of flat cross section, as shown, which is normally biased outwardly by its own elastic properties to close the chamber port 35. This allows a low pressure outside the return chamber 10, or at least behind the front face 7, to pass through the chamber port 35 to equalize the pressure in the return chamber 10 and the front face 7, Back 9. Valve 24 is adjusted or selected to open at the desired pressure differential.

[0167] As shown in at least Figures 2 and 5, a one-way valve 19 is provided from the working chamber 3 to the return chamber. This one-way valve opens when the back of the working load 4 is exposed to residual pressure, such as when the working load moves to or toward the second end 8 as shown in Figures 2 and 5. If there is residual pressure, the residual pressure is vented from the working chamber 3 through the one-way valve 19 to the return chamber 10. Thus, the device can capture and utilize the pressure that performed work as the working load moved to or toward the second end to return the working load 4 to the first end 5.

[0168] In a perfectly sealed system, this would theoretically never occur. However, in practice, it can occur if an air bleed occurs, for example from the anvil port 45 in front of the front face 7, as the working load is transferred, for example, by a seal leak, towards the second end or elsewhere, such as to the second end or to the ambient environment or atmosphere. Such a check valve 23 is utilized when an undesirable pressure imbalance occurs that would impair the return of the working load.

[0169] A trigger valve arrangement which operates the device of Figures 1 to 3 and also the discharge valve is shown in Figures 4 to 12, which show the trigger valve arrangement and the discharge valve which it operates, albeit indirectly. In this variant, a one-way valve is incorporated into the discharge valve 2, and essentially the one-way valve recirculates the air into the return chamber 10.

[0170] The overall configuration of the variant shown in FIGS. 1-3 is retained, and the discharge valve 2 (with a cross-sectional line (added in FIG. 4)) has a discharge chamber 21 and moves to an open position 12 as shown in FIGS. 5, 6, 9, and 10. In the open position 12 of the discharge valve 2, the discharge chamber 21 is fluidly connected to an outlet 30 provided in the side wall of the working chamber 3 via a discharge valve port 33 as shown in FIG. 9. The discharge chamber 21 is provided with a leakage path, i.e., a differential flow rate to the discharge 32 as shown in FIGS. 9 and 10. The differential flow rate in the discharge chamber 21 or the leakage path from the discharge chamber 21 is adjusted to create a pressure in the discharge chamber 21 sufficient to overcome the biasing means 29. If the spring constant of the biasing means 29 is very small, the path difference or leakage path only needs to be small enough to provide a sufficient overall force.

[0171] Thus, when the discharge valve 2 is actuated to open, Back The working fluid trapped between 9 and the working chamber 3 can drain the working chamber 3 as the working load 4 returns to the first end 5. A pressure difference is therefore created between the front and back sides, supporting the increase in pressure at the front side, causing the working load to return from the second end to or towards the first end when the drain valve opens.

[0172] When the dosing valve 48 is actuated, the working fluid 6 is discharged from the dosing chamber 52 into the working chamber, but for these variations of the device 1 of Figures 1-13 it must be triggered to drive the working load 4. This is controlled by a trigger valve 50, as shown in Figures 4-12, and particularly in combination with the hammer 46 in Figures 8-12.

[0173] As shown in detail in Figure 8, the device has a high pressure actuation fluid (e.g., actuation fluid 6) that drives a hammer 46. The hammer 46 is again able to slide linearly parallel to the longitudinal axis 15, with the hammer 46 moving to the left in Figure 8 and to the right in Figure 10.

[0174] 10, it can be seen that the hammer 46 has a driven chamber 49 and to the right of the hammer 46 is a discharge or trigger chamber 47 (better seen in FIG. 8). The two chambers are separated by a hammer piston 51 and its seal, which substantially seals the two chambers from one another to prevent hydraulic fluid from flowing from one chamber to the other.

[0175] In a preferred variant, the pressure acting on driven chamber 49 and discharge chamber 47 is the same since they both receive pressurized working fluid, whether directly or indirectly, from the same source 72. In the example shown in Figure 4 and in more detail in Figure 8, driven chamber 49 is indirectly pressurized from pressure source 72 via a dosing chamber. However, it may also be supplied from discharge chamber 47 or independently of these chambers, for example directly from source 72. This can be achieved by a direct connection between source 72 and driven chamber 49, for example by a conduit between the two.

[0176] As can be seen in FIG. 9, the hammer piston 51 presents an effective driven area 75 in the driven chamber 49 and an effective discharge area 76 in the discharge chamber 47. The effective area in this embodiment refers to the area that the hammer piston 51 presents in each chamber against which the hydraulic fluid acts to move the hammer piston 51. The effective area is the area perpendicular to the working or sliding axis of the hammer piston 51. It does not matter whether the surfaces that form the effective area are perpendicular to the working axis or not. However, in the example shown, the surfaces present in each chamber of the hammer piston 51 are also perpendicular to the working axis.

[0177] In a preferred embodiment, in the cocked position shown in FIG. 9, there is a net force that drives the hammer piston 51 and hammer 46 fully into the driven chamber 49, which is fully to the left in FIG. 9. The hammer / hammer piston assembly comes to rest against a stop 74. In a preferred embodiment, the stop includes an energy absorber such as an O-ring as shown, or a hard metal stop that is sufficiently resilient not to deform with many movements of the hammer. The net force, and stop, provides a repeatable and consistent cocked position for the hammer 46. This results in a repeatable and consistent opening of the dosing valve 48 when impacted by the hammer 46.

[0178] This net force in the preferred embodiment is achieved by the ejection effective area 76 being larger than the driven effective area 75, since the actuating fluid pressure in each chamber is the same. However, it is equally contemplated that the effective areas may be the same or different, or that different pressures may be applied (e.g., the pressure applied to the driven chamber may be adjusted to be lower than the pressure in the ejection chamber), with or without an additional bias, such as from a spring. The advantage of using only actuating fluid to actuate the hammer is that there is spring energy in the spring that needs to be overcome if a bias, such as a spring, is present, while the remaining energy can be removed (by ejecting the chamber). However, the bias may be useful to overcome inherent friction.

[0179] Driven chamber 49 as shown is charged with actuating fluid 6 from dosing chamber 52 through port 57, as seen in FIG. 9. However, driven chamber 49 may be charged directly from source 72 without an intermediate chamber such as a dosing chamber. In this shown example, dosing chamber 52 is a ring-shaped chamber surrounding the actuating chamber, the two being concentric on axis 15. Port 57 may be modified to restrict flow from dosing chamber 52 to driven chamber 49 using a fixed or adjustable restrictive element, baffle, or other restrictive geometry (e.g., reduced diameter).

[0180] At least delivery chamber 47, seen in FIG. 8, is loaded from a source 72 selectively selected by trigger valve 50. When trigger valve 50 is in the first valve position shown in FIG. 8, there is a fluid path from source 72 through trigger valve 50 to delivery chamber 47 and up delivery passage 56. Dosage chamber 52 is also loaded, in this case through port 58. The filling of delivery chamber 47 and delivery chamber 52 is sequential, with one loading before the other, and in a preferred form of the invention, delivery chamber 47 begins loading before dose chamber 52. As seen in FIG. 8, this path is generally loaded from a source of high pressure actuation fluid 72. The timing of the loading of delivery chamber 47 and delivery chamber 52 is determined by the relative positions of spool seal 62 and spool passage 64. In a preferred embodiment, as described above, the timing is such that delivery chamber 47 fills, or at least begins to fill, before dose chamber 52.

[0181] The dosing chamber 52 and the path for filling the expulsion chamber 46 are provided by a trigger valve 50, in this case provided as a spool valve.

[0182] As shown in Figure 8, spool seals 62 are formed at various locations between the inner diameter of the spool bore 65 and the outer diameter of the spool valve. The seals are separated by spacers 61. In a preferred form, the spacers 61 allow the spool seals 62 a small amount of axial movement, i.e., in the direction of movement of the spool 63 of the trigger valve 50. This reduces static friction of the seals, and in the case of O-rings, allows the seals to partially roll or move, thus further reducing friction.

[0183] Which of these spool seals 62A, 62B, 62C and 62D provides a seal depends on the position of the spool 63 along the bore. The spool 63 can move linearly relative to the spool bore 65, as indicated by the arrows in FIG.

[0184] During preparation for firing, in the first valve position as shown in FIG. 8, dosing chamber 52, ejection chamber 47, and driven chamber 49 are all pressurized with actuating fluid 6 from source 72, and spool seals 62A and 62D seal between the inner diameter of spool bore 65 and the outer diameter of spool 63. Spacer 61 has a fluid communication path, e.g., a hole, from its outer diameter to its inner diameter. Spool spacer 61 allows actuating fluid to travel from the spool bore inner diameter / spacer outer diameter to the spacer inner diameter / spool outer diameter. Thus, actuating fluid 6 can enter spool bore 65 at its outer diameter, e.g., from source 72 of high-pressure actuating fluid, and pass to and along the spacer inner diameter / spool outer diameter as far as the spool seals (in this case, seals 62A and 62D, as seen in FIG. 8) allow. Because the spool bore inner diameter and the spool outer diameter are sealed, actuating fluid cannot pass past these seals.

[0185] For clarity, the spacers 61 are hollow cylinders and are packed between the spool seals 62. The spacers 61 have passages in fluid communication with the ports, discharge passages, or outlets to the ambient, allowing fluid to pass to or from their outer diameter and to or from their inner diameter to the spool 63 of the spool valve forming the trigger valve 50. The spool has a spool passage 64, for example as a relief in the outer diameter of the spool 63, allowing fluid to pass under the spool seals 62 and thus flow from the adjacent spacer 61 to the next. This allows selective flow of fluid from the dose chamber to the discharge chamber or ambient, and from the discharge chamber to ambient (this will be explained further shortly).

[0186] Within the bore are two other seals 62B and 62C, which in the ready / load position of FIG. 8 are located adjacent to spool passages 64 that allow hydraulic fluid to bypass seals 62B and 62C, respectively.

[0187] Therefore, any port within these two seals 62A and 62D can allow the flow of actuation fluid. Thus, fluid 6 from source 72 can enter port 58, charge dosing chamber 52 (and then through port passage 57 to driven chamber 49), enter discharge passage 56, and pressurize discharge chamber 47.

[0188] In the ready to fire / load position (first valve position), the hammer 46 is held by a net force acting axially on the hammer piston 51 through the driven chamber 49 and the ejection chamber 47 as shown in FIG. 8, and therefore the hammer 46 is as described above.

[0189] In Figure 8, the device 1 is primed and ready to fire. The dosing chamber 52 is filled with high-pressure actuating fluid 6 and is held closed from the actuation chamber 3 by the pressure of the high-pressure actuating fluid 6 and a cage spring 54. The dosing valve 48 is typically biased closed by a combination of pressure and / or spring force. When a spring force is used to close the dosing valve 48, this spring force is transmitted to the dosing valve 48 through a surrounding element called a spring cage 53. The spring cage 53 captures a cage spring 54 at one end, which is in a compressed state and biases the cage spring 53 to the right as viewed in Figure 9.

[0190] The spring cage 53 may be part of the dosing valve 48 or may be separate from the dosing valve 48 .

[0191] The opposite end of the spring cage 53 engages the dosing valve 48. In this case, the lower portion of the spring cage engages the dosing valve 48 and transmits a biasing force to the cage spring 53, holding the dosing valve 48 closed.

[0192] The spring cage 53 extends into the dose chamber 52 to the left of the dose valve 48 as viewed in Figure 9, providing sufficient spring length to provide the correct closing force and travel distance for the dose valve 48. This length may be adjusted to vary the closing force as required. The spring cage 53 features porting 55 that allows unrestricted flow from the dose chamber, through the dose valve, to the actuation chamber.

[0193] High pressure fluid is also moving to both sides of the hammer piston 51, maintaining the force imbalance as described above. In this case, the pressure is the same on both sides of the hammer piston 51. However, the effective area on each side of the hammer piston 51 is different (greater on the trigger chamber side than on the driven chamber side), and the hammer 46 is pressed against the stop 74 by a net force, so there is no movement. However, as already mentioned, there may be different pressures, and therefore different areas, in each chamber of the hammer, and conversely, there may be an optional spring (not shown) acting on the hammer 46 to drive the hammer or assist its return, to hold the hammer in place.

[0194] High pressure fluid from the dosing chamber travels to the driven chamber 49 via port passage 57. High pressure fluid from the dosing chamber also passes through the trigger valve and is loaded into the ejection chamber 47 via port 58.

[0195] However, in other configurations, driven chamber 49 may be supplied with high pressure fluid directly from a high pressure fluid source, without passing through an intermediate volume such as a dosing chamber.

[0196] In the illustrated variant, the trigger valve 50 is a spool valve. It has a moving spool 63 that can selectively open and close the pathways as described, and preferably has three positions. The first valve position, as shown, for example, in FIG. 8, opens the supply to the actuation chamber, either directly or indirectly, from the high-pressure source, and activates it. In this position, the trigger valve opens the supply to the dosing chamber and closes the vent path therefrom, opens the supply to the dosing chamber and trigger chamber, and prepares the dosing valve to be inoperative. The second valve position, as shown, for example, in FIG. 10, activates the device and closes the supply from the high-pressure source. In this position, the trigger valve closes the supply to the device, particularly to the dosing chamber and trigger chamber, and vents, exhausts, or releases the high-pressure actuation fluid in the trigger chamber to the environment. The trigger valve also has a third valve position for safeguarding the device, as shown, for example, in FIG. 12. In this position, the trigger valve cuts off the supply to the dosing chamber, vents, vents or exhausts the dosing chamber to the environment, and optionally vents, vents or exhausts one or more of the remaining operating chambers.

[0197] 8 only allows fluid to flow from source 72 to dose chamber 52, and from there to ejection chamber 47 in the embodiment shown. As noted above, the driven chamber may alternatively be fed directly from source 72.

[0198] The pathways of the trigger valve 50 can be understood by considering that the spool seal 62 seals only against the outer diameter of the spool 63. Thus, in the illustrated embodiment, it can be seen that there is a first fluid pathway 69 from the port 58 to the left in FIG. 8, through the spool passage 64, bypassing the spool seal 62, into the discharge passage 56, and into the discharge chamber 47. Importantly, there is no pathway for the source 72 to vent to the ambient 14 as the trigger valve 50 moves from the ready position to the fire position to the safe position.

[0199] The pressure release may be an uncontrolled discharge from the working chamber, or may be a slow or controlled release or vent depending on the application. For example, in safety situations, it may be desirable to release the air charge to the surroundings in a slow manner or through a muffler or the like to reduce noise and / or prevent sudden high pressure flows that may endanger the user or cause a nuisance to those around.

[0200] Pressure from source 72 is also taken to charge the dosing chamber, the driven chamber and the ejection chamber, and via the second valve position, source 72 is closed when the ejection chamber is released to eject the device. Only the ejection chamber pressure charge is then vented to the ambient environment 14.

[0201] Similarly, when the trigger valve 50 is moved to the third valve position, which is the safe state position, the source 72 is sealed and the hydraulic fluid charges in the driven and dosing chambers are vented to the ambient environment 14. In the safe state position, the discharge of the charges from the dosing chambers at least safes the device, preventing actuation, such as firing a device / work (in the case of a fastening gun) or work performed by the device. In the optional safe position, the high-pressure hydraulic fluid is discharged from one or more operating chambers, such as the dosing chamber, the driven chamber, and the release / trigger chamber, thereby preventing any actuation by the high-pressure hydraulic fluid. In the optional safe position, the driven chamber is released before the release / trigger chamber (in a similar manner via ports and bypass passages in the trigger valve). This prevents the hammer from impacting the dosing valve because the driven chamber is released before the trigger chamber, thus maintaining the overall net force on the hammer toward the driven chamber, away from the dosing valve.

[0202] Regardless of the position of the trigger valve, in the preferred form there is no direct path from the high pressure source to the working chamber, in other words the high pressure source cannot be uncontrollably released from the working chamber.

[0203] The hammer 46 is triggered by venting the pressure in the trigger chamber 47 through a vent passage 56 to a lower pressure, such as the ambient environment or atmosphere 14. This is accomplished by moving the trigger valve 50 to the eject position, as seen in FIG. 10. In the example shown, the spool 63 is moved to the left in FIG. 10 to allow damping. As shown in FIG. 9, movement of the spool 63 provides a second fluid path 70, allowing fluid to vent from the vent chamber 47 through the vent passage 56 to the spool, bypassing the spool seal 62D to the left (in FIG. 9) through the spool passage 64. In the manner shown in FIG. 10, a leak path exists between the inner diameter of the spool bore 65 and the outer diameter of the spool piston 66, or in various other ways as will be described below.

[0204] The trigger valve 50 can be actuated by a user using an actuator 73 engaged with the spool 64 of the trigger valve 50, for example, by actuating a trigger, either directly or indirectly, or by other means to actuate the trigger valve 50. In this case, the trigger drives the spool 63 of the trigger valve 50 to the left in FIG. 9, venting the trigger chamber 47 via the discharge passage 56 and out to the ambient environment 14 via the leak path 60. This actuation, whether acting directly on the spool or indirectly, for example, via the trigger, can be against a return spring (not shown) that returns the spool 63 to the primed or ready-to-fire position.

[0205] Two additional variations of the trigger valve 50 outlet to the ambient environment 14 are shown in FIGS. 11A and 11B. In FIG. 11A, there is an additional sealing element on the spool 63, such as shown in FIG. 12B as a spool seal 62E on the spool piston 66 that seals against and moves relative to the inner diameter of the spool bore 65. Alternatively, the sealing element 62 can be mounted in a groove on the spool bore 65 for sealing against and moving relative to the spool piston 66, elongated or otherwise. Instead of a restriction or leak path as in the previous variation of FIG. 8, this allows for increased pressure bias on the spool 63 via pressure on the spool piston 66 acting to the left, opening more quickly and aiding pressure relief performance. This can be used to force the spool valve 50 to move quickly to the fully open position, thereby releasing hydraulic fluid from the release chamber. Thus, if the trigger valve 50 is partially actuated, this feature ensures that it will move fully until actuated, i.e., releasing the release chamber.

[0206] A further variation in the exit path for high-pressure fluid upon discharge from the discharge chamber is shown in Figure 11B, which may be used in place of or in addition to Figure 11A. This variation allows for either the discharge passage or the bypass passage 67 to open when the spool 63 moves a sufficient distance to the left. Two variations are shown: passage 67A exiting the side of the spool bore 65, or using a spool passage that bypasses the spool piston 66 as passage 67B.

[0207] This allows for an initial slow release if there is a leak path, followed by a sudden release during extreme movement while protecting the spool piston 66. Additionally, when coupled with a seal such as that of Figure 11A, this helps move the spool 63, allowing for subsequent rapid pressure relief.

[0208] The "fire" sequence begins when the trigger chamber 47 is vented. When the trigger chamber 47 is vented, a pressure differential is created between the driven chamber 49 (higher pressure) and the trigger chamber 47 (vented to a lower pressure, such as the ambient environment 14).

[0209] The higher pressure in the driven chamber 49 then drives the hammer 46 to impact the dosing valve 48, immediately opening the dosing valve 48 and allowing the working fluid 6 from the dosing chamber 52 to flow into the working chamber 4 and drive the working load 4. This has a beneficial impact on the available performance of the tool in terms of both efficiency and packaging.

[0210] The configuration of the present invention also prevents dosing chamber 52 from venting through port passage 57 under normal triggering use because there is no path therefrom to ambient environment 14. Similarly, except for the variation thereof shown in FIG. 11C , there is no leak path from port 58 to ambient environment 14 under normal triggering because spool 63 of trigger valve 50 does not fluidly connect dosing chamber 52 to ambient environment 14. Discharge chamber 47 and discharge passage 56 only discharge to ambient environment 14 when spool 63 moves from the ready to fire state to the firing state. Because source 72 is sealed from the environment, there is no continuous bleed path for high-pressure actuating fluid from the source. In this manner, the present invention makes more efficient use of the actuating fluid charge in dosing chamber 52.

[0211] The hammer 46 can then be returned to the ready to fire or first position by re-establishing the trigger chamber pressure and the hammer backforce bias or imbalance that occurs between the pressure region 47 and the driven chamber 49 in addition to any resilient force biasing member acting on the hammer.

[0212] The hammer 46 is then returned to the ready-to-fire state (dosing valve 48) by restoring a pressure equal to the resultant force between the trigger chamber 47 and the driven chamber 49.

[0213] Additionally, the hammer 46 may be at least partially driven towards the dosing valve 48 by a spring (not shown), or may return the hammer 46 so that it does not strike the dosing valve 48. An elastic energy exchange may occur between the hammer 46 and the dosing valve 48 so that the hammer 46 bounces back. For example, when the dosing valve closes (moves to the left in FIG. 9 ), enough energy is imparted to the hammer to push it back at least part way, allowing the pressure differential in favor of the discharge chamber to move it the remaining part.

[0214] A further option, shown in FIG. 11C , is the presence of a transfer port 68 between the dosing chamber 52 and the discharge passage 56, and thus to the discharge chamber 47. Typically, this is a restricted-size port 68 to allow pressure flow but limit its volume or velocity. This slightly alters the actuation sequence and significantly alters the pressure balance. The effect is to more quickly equalize the pressure on the hammer 46 after the hammer 46 strikes, allowing for a faster hammer reset and faster closure of the dispense valve 48, leading to a more efficient actuation stroke. This option has a significant tradeoff: if the trigger is held in the eject position (left side), a leak path exists from the dosing chamber to the atmosphere through the trigger spool 63. In this situation, the trigger can be momentary, allowing the spool 63 to return to its closed state as quickly as possible. The flow capacity exiting the trigger valve 50 during discharge must be significantly greater than the restricted flow transfer port 68 from the dosing chamber to the discharge chamber. This means that any pressure signal from the dosing chamber to the discharge chamber is lost to the ambient environment, and therefore is a less preferred variant.

[0215] When the trigger valve 50 is moved rightward back to the position of FIG. 8, the discharge chamber 47 is repressurized, moving the hammer 46 back to the ready to strike position and immediately resetting the trigger system.

[0216] The frequency of high-pressure air power tools requires a "safety" method. The trigger valve 50 of the present invention has both a "safety" energy release function, as described below, and a "firing" function, as described above, that operates within a single movable body or valve assembly, moving in one direction to operate and in the opposite direction to achieve safety.

[0217] The trigger valve 50 has a third position for safeguarding the device 1 as shown in Figure 12. When the trigger valve 50 is placed in the safe state position as described below, there is a path to the ambient environment 14, but this is not part of the normal trigger actuation that fires the device, it is actuated by the trigger valve, but is part of safeguarding the device.

[0218] Again, the path of actuating fluid 6 in the safe state position depends on the interaction of the trigger valve with spool seal 62, spool passage 64, and spacer 61. Specifically, as shown in FIG. 12, spool seals 62D, 62C, and 62B all seal the inner diameter of spool bore 65 and the outer diameter of spool 63. Therefore, actuating fluid trapped between them cannot escape. That is, high-pressure fluid source 72 is sealed because it is located between seals 62B and 62C, and discharge passage 56 is also sealed because it is located between seals 62C and 62D. However, port 58 can be freely vented using spacer 61, bypassing spool seal 62A using spool passage 64. From there, discharged fluid 71 can pass to low pressure or ambient environment 14. In this way, actuating fluid 6 in driven chamber 49 and dispensing chamber 52 can be removed from the device. This prevents the device from being actuated or dispensed, thereby making the device safe.

[0219] Trigger valve 50 is a three-position air-powered trigger that pushes hydraulic fluid 6 out of dosing chamber 52 and through port 58 to a low-pressure safe position (e.g., ambient environment 14 as shown) (to the right as viewed in FIG. 12 ) to make the device safe when used with a fastening tool such as a nail gun. In this way, even though a “charge” of hydraulic fluid, such as highly compressed air, is removed from dosing chamber 52 and dosing valve 48 is open, it is not charged to drive a working load 4, and therefore a device incorporating the present invention is safe.

[0220] However, when the trigger valve 50 is actuated or pulled to the left (as viewed in FIG. 9), hydraulic fluid is expelled from the discharge chamber 47 to fire the device 1. The trigger valve 50 is provided with a leak path 60 to the left which acts on the trigger valve 50 as shown to increase the opening speed of the trigger valve.

[0221] For the exhaust valve 2 of Figure 4, a baffle 26 and baffle ports 27 are shown in the return chamber 10. These are used to adjust the rate at which pressure builds up against the working surface 28 of the exhaust valve 2. Under dynamic loading, pressure on the side of the second end 8 of the baffle builds up more quickly than pressure on the side of the first end 5 of the baffle due to the reduced size of the baffle ports 27. The smaller the baffle ports 27, the slower the pressure of the return fluid 42 builds up against the working surface 28.

[0222] In this embodiment, the working surface 28 of the discharge valve 2 is formed in part by a valve member 37 (in this case, an O-ring 34). However, the valve member 37 may be any other suitable sealing structure capable of sealing and unsealing, such as, but not limited to, an X-ring, a lip seal, or other sealing elements of continuous or variable cross-section. When the pressure difference in the return chamber 10 is large, as the actuation load moves the actuation chamber downward toward the second end 8, the return fluid is forced to act on the valve member 37 (in this case, the O-ring 34) to unseal the inter-chamber port 40 as shown in FIG. 8 . In doing so, the force difference between the pressure in the return chamber 10 and the discharge chamber 21 due to the outlet 30 moves the discharge valve 2 to or toward the open position 12 (i.e., to the left in the drawing). When open, the discharge valve 2 forms the discharge chamber 21, as described above, between the body of the discharge valve 2 and the surface of the surrounding housing 36.

[0223] The working surface 28 of the discharge valve 2 and the opposing inner surface within the discharge chamber 21 are adjusted so that the pressure in the discharge chamber 21 will keep the discharge valve 2 open even if the pressure in the return chamber 10 falls below the pressure that would cause the discharge valve to open. The pressure in the discharge chamber 21 can act to keep the discharge valve 21 open and, if necessary, to open it further. Adjustments may be made by using seals at the front and back and on the inner and outer diameters of the discharge valve to create different sized areas for pressure and actuating the discharge valve 20 over these different sized areas.

[0224] The discharge valve 2 is normally biased closed by a biasing means 29, in this case a spring, which is selected based on the pressure experienced in the return chamber 10 and the pressure experienced in the discharge chamber 21 so that the discharge valve 2 opens, stays open and closes as required in accordance with the timing of the system.

[0225] The discharge valve 2 as shown is sealed at its outer and inner periphery by seals 38 (in this case O-rings), although any suitable sealing member and material may be used.

[0226] Highly pressurized working fluid 6 is delivered to the first end 5 of the working load 4, for example by opening a dosing valve 48. Back 9, which directs the working load 4 towards the second end 8 of the working chamber, as shown by the arrow in FIG.

[0227] The discharge valve 2 in this modification is also ring-shaped, and has at least one, preferably several through holes formed from the inner periphery to the outer periphery to form a discharge valve port 33 .

[0228] The discharge valve 2 also has a discharge valve chamber surface 39, as shown in Figure 9. Normally, the discharge valve closes when the pressure differential at the working surface 28 is not sufficient to overcome the biasing means 29. However, this pressure differential and the fluid flowing into and out of the discharge chamber 21, restricted by the leakage path, acting on the discharge chamber 21 and the discharge valve chamber surface 39, holds the discharge valve 2 in the open position 12. Thus, when the working load 4 moves to the ready position at or towards the first end 5, the pressure of the working load 4 Back The pressure difference at 9 continues to cause discharge.

[0229] As the working load 4 continues to move towards the first end 5 to the working chamber 3, the pressure in the return chamber 10 increases Back 9. This is most likely evident towards the end of the stroke, i.e., first end 5, of the working load 4, as the discharge valve 2 may move towards the closed state 11. In this case, there will be a pressure difference between the discharge chamber 33, e.g., atmosphere 14, and the return chamber 10. In this case, the valve member 37 opens, allowing fluid to move through the chamber port 40 into the return chamber 10, as shown by the arrow in FIG. 11. This further assists the working load 4 in returning to the ready position. To reduce the level of friction on the valve member 37, for example, an O-ring 34 or other suitably shaped seal is pressed and compressed only when moved by the fluid flow, so that in the absence of a pressure differential or flow the passage is statically closed and the valve member 37 does not seal and experiences little or no friction. The method of operation will now be further described.

[0230] The embodiments of Figures 1-3, including a discharge valve actuated by the trigger valve of Figures 4-12, operate in a similar manner, with Figures 3(A)-3(D) adding recirculation using chamber port 35 and a check valve 23 such as reed valve 24. Figures 4-11 operate on the same principle, with recirculation provided within the discharge valve itself. In each figure, the arrows on the actuating load 4 illustrate the direction of movement.

[0231] Upon actuation by an external mechanism, spool 63 moves left, releasing pressure from discharge chamber 47 and striking hammer 46 into dosing valve 48. The dosing valve cracks open, uncovering dosing chamber 52 from actuation chamber 3. A working fluid, which may be a gas such as, but not limited to, air, is then pressurized to displace actuation load 4 in actuation chamber 3, as shown in FIGS. Back 9. As the working load is urged by the working fluid 6 towards the second end 8, the charge of the working load 6 expands within the rapidly forming volume formed by the working cylinder 3 and the working load 4.

[0232] As soon as the required charge of actuating fluid has been delivered by dosing valve 48 from dosing chamber 52 into actuation chamber 3, dosing valve 48 recloses, sealing dosing chamber 52 from actuation chamber 3. Spool 63 also returns to the position of FIG. 8 and ejection chamber 47 is again biased by high pressure fluid from dosing chamber 52 and source 72, helping to return hammer 46 to its ready-to-fire force-balanced position. Dosing chamber 52 can also be supplied with high pressure fluid from a supply 72 of high pressure fluid, for example a high-pressure tank, if required, and adjusted from the tank pressure to the operating pressure of the device.

[0233] As the working load 4 displaces the air or similar fluid in the working chamber 3 downward, the working chamber is forced down in front of the front face 7. As a result, this fluid, conveniently termed here return fluid 42, enters the return chamber 10 through either the first fluid connection 17 or the second fluid connection 18.

[0234] When the working load 4 is constrained as shown in this example, the volume defined by the front face 7 and the working chamber 3 becomes closed. However, when it is desired to eject the working load, the principle still applies: there is a fluid pressure wave in front of the piston as the working load moves down the working chamber 3. If the fluid connections 17, 18 are shaped differently, at least some of this return fluid 42 will be trapped.

[0235] When the return fluid enters the return chamber, the return fluid acts on the operating surface 28 of the discharge valve 2. When the pressure of the return fluid 42 acting on the operating surface 28 overcomes the biasing force, the discharge valve 2, which is normally biased to the closed state by the biasing means 29, is opened. This is the same as the modified example shown in Figures 1 to 12.

[0236] The exhaust valve 2 then moves to or towards the open state 12. The high pressure working fluid in the volume of the return chamber 10 then returns to the working chamber 3 and acts to push the working load 4 back into the working chamber, returning the working load 4 from the second end 8 to the first end 5.

[0237] The actuation load 4 can now begin to move freely through the actuation chamber 3 towards the first end 5. Alternatively, as the actuation load 4 moves towards the first end 5, the actuation chamber 3, Back The volume defined by 9 and first end 5 builds up pressure which resists movement of the working load 4 and the exhaust valve is now in an open state 12, providing a flow path for the pressure to be exhausted to a lower pressure, for example atmosphere 14, although lower pressures would likely also be appropriate. In the above-mentioned exhaust valve 2, a flow path to low pressure is provided for the exhaust fluid 41, as shown in Figures 2, 5, 6, 9 and 10. It is clear that the exhaust fluid is not combustion gas, but rather the working fluid 6 that expands from high pressure into the volume of the working chamber 3 and acts on the working load 4.

[0238] 1 and 2, this open discharge path for the discharge fluid 41 is sufficient to return the working load 4 to the ready position at the first end 5. In FIG.

[0239] However, in some circumstances, low pressure may develop in the return chamber 10 which may prevent the working load 4 from returning completely to the first end 5 . In this case, the variants of Figures 3(A) to 3(D) and 4 to 11 that allow for recirculation are used. 3(A)-3(D), in the event of low pressure occurring in the volume of the return chamber 10 defined by the working chamber 3, the second end 8, and the front face 7, a chamber port 35 is provided with a check valve 23, illustrated as a reed valve 24. The check valve opens at a design pressure differential outside the return chamber 10 (e.g., atmospheric pressure 14), allowing recirculation. Back 9, thereby ensuring complete transfer of the operating load to the first end 5. The variants of Figures 4 to 11 operate on a similar principle to those incorporating a discharge valve 2 that recirculates to the return chamber 10, with the added expansion capability of holding the discharge valve 2 open. The variations of Figures 4-11 also have the exhaust valve 2 in the open state 12 as a result of return fluid pressure 42 in the return chamber 10 acting on the working surface 28. A portion of the working surface 28 is defined by a moving valve member 37, in this case an O-ring 34, which can move to seal and unseal the working surface 28 (as described below). When the working surface 28 is sealed, the O-ring 34 also provides pressure to the exhaust valve 2, causing it to move to the open position 12 or assisting it to remain in the open position 12.

[0240] When the discharge valve 2 moves to the open position 12, the discharge valve 2 is defined between the discharge valve chamber face 39 and the interior of the housing of the discharge chamber 21. In the open position 12, working fluid can pass through the outlet 30, through the discharge valve port 33 into the discharge chamber 21, and then through the restriction or leakage path to the discharge 32. The flow rate through the restriction or leakage path from the discharge chamber 21 is less than the flow rate into the discharge chamber 21, thus creating pressure that helps to hold the discharge valve 2 in the open position 12.

[0241] The flow path from the sidewall outlet 30 to the discharge chamber 21 and then from the discharge chamber 21 to the discharge 32 may be throttled, for example by a leak path or another restriction that allows different amounts of fluid to flow into and out of the discharge chamber. This baffling or restriction allows pressure to build in the discharge chamber 21 and slowly releases the baffling or restriction to help regulate the opening time of the discharge valve 2.

[0242] The working load 4 can then be moved by the action of the return fluid 42 to the working chamber 3 towards the first end 5 as described above.

[0243] To increase the open time of the discharge valve 2 and provide another means of adjusting opening and closing, an increase in pressure acting on the discharge chamber 21, particularly the discharge valve chamber face 39 and its opposing face, continues to hold the discharge valve open even after the pressure in the return chamber has decreased to close 11 the discharge valve 2. This increases the open time of the discharge valve and therefore increases the ability of the working load 4 to be reliably returned to the first end.

[0244] Furthermore, the discharge valve is provided with an inter-chamber port 40 between the discharge chamber 21 and the return chamber 10, preferably between the discharge 32 and the return chamber 10. In a preferred embodiment, this inter-chamber port 40 is provided with a valve member 37. Thus, when there is a pressure difference between the discharge chamber 21 or the discharge 32 and the return chamber 10, the valve member 37 opens, allowing return fluid 42 to be recirculated to the return chamber, effectively acting as shown in Figures 7 and 11. Thus, even when the discharge valve 2 is closed, the working load 4 is reliably returned to the first end 5 and put into an actuated state.

[0245] Moving the discharge valve to or toward the first end facilitates assembly and reduces parts count. Additionally, having the discharge be a side discharge reduces complexity compared to an axial port at the first end that extends parallel to the longitudinal axis 15. This results in a compact structure with fewer parts, lower cost, and easier assembly and maintenance.

[0246] The present invention utilizes a hammer coupled with the inflow blocking function (from the high pressure source) of the trigger system to create extremely short pulses of flow within the working chamber, which allows for extremely high thermodynamic efficiency and cycle rates.

[0247] A short duration pulse of high pressure working fluid means that a small amount of working fluid enters the working chamber, but is then able to expand by a large factor that is strongly related to the thermodynamic efficiency of the compressed fluid mechanical system.

[0248] By having the necessary pneumatic trigger components perform both the triggering and "go to safety" functions, the present invention maintains all of the performance metrics discussed above while meeting regulatory and good safety design requirements. The above description of the invention encompasses preferred forms of the invention. Modifications may be made to the invention without departing from the scope of the invention.

Claims

1. an actuation trigger for the device, comprising: a dosing chamber holding a charge of high pressure actuating fluid received from a high pressure source; a dosing valve that is biased closed to seal the dosing chamber from the actuation chamber and retain a charge in the dosing chamber; a hammer actuated by a piston having a driven chamber on a first side of the piston and a trigger chamber on a second side of the piston sealed from the first side of the piston, the driven chamber receiving high pressure actuation fluid directly or indirectly from the high pressure source; a trigger valve selectively supplying high pressure actuating fluid to or releasing high pressure actuating fluid from the trigger chamber; having or including When the hammer has high pressure hydraulic fluid in both the driven chamber and the trigger chamber, the hammer is held in a first position by a force imbalance, and when high pressure hydraulic fluid is released from the trigger chamber, the hammer is driven to or toward a second position toward the trigger chamber; An actuation trigger for the device, wherein when the hammer is driven to or towards the second position, it strikes the dosing valve, unseating the dosing valve and opening the dosing chamber and the actuation chamber, thereby allowing the charge to enter the actuation chamber and do work therein.

2. 2. The actuation trigger of claim 1, wherein the force imbalance results from a greater acting area of ​​high pressure actuating fluid on a trigger chamber side of the piston than on a driven chamber side of the piston.

3. 3. The actuation trigger of claim 1 or 2, wherein the trigger valve is a sliding spool valve.

4. 4. An actuation trigger as claimed in any one of claims 1 to 3, wherein when the dosing valve is opened to communicate the dosing chamber with the actuation chamber, there is no supply from the high pressure source to the actuation chamber, whether through the trigger valve or not.

5. the trigger valve selectively releases high pressure actuating fluid from one of the "actuating chambers" - the dosing chamber, the driven chamber, or the trigger chamber - into the ambient environment, or supplies high pressure actuating fluid directly or indirectly from the high pressure source to one of the "actuating chambers" - the dosing chamber, the driven chamber, or the trigger chamber - to activate the device; The trigger valve has at least two positions: a. a first valve position in which the high pressure source directly or indirectly supplies the operating chamber to an operable state, wherein the trigger valve is: i. opening the supply to said dosing chamber and closing any vents therefrom; ii. opening the supply to the dosing valve and the trigger chamber and preparing but not actuating the dosing valve to open; b. a second valve position that activates the device and closes off the supply from the high pressure source, wherein the trigger valve: i. closing off the supply to the device including the dosing chamber and the trigger chamber; ii. venting the trigger chamber to the ambient environment; 5. The actuation trigger of claim 1, wherein the trigger comprises:

6. The trigger valve has a third valve position that renders the device safe, wherein the trigger valve: a. closing off the supply to the dosing chamber; b. Venting the dosing chamber to the ambient environment, and c. Optionally, vent one or more of the remaining operating rooms; An actuation trigger according to any one of claims 1 to 5.

7. An actuation trigger as claimed in any preceding claim, wherein the high pressure actuation fluid is prevented from exiting the high pressure source when the trigger valve closes the supply to the device.

8. An actuation trigger according to any preceding claim, wherein the trigger chamber, when supplied, is filled before the dosing chamber.

9. An actuation trigger as claimed in any preceding claim, wherein the hammer slides along a first sliding axis and the dosing valve slides along a second sliding axis.

10. 10. The actuation trigger of claim 9, wherein the first and second sliding axes are at least parallel and concentric.

11. An actuation trigger according to any preceding claim, wherein the dosing valve is an annular ring having an annular ring sealing surface sealing the dosing chamber from the actuation chamber.

12. An actuation trigger according to any preceding claim, wherein the dosing valve is biased closed by a spring.

13. An actuation trigger according to any preceding claim, wherein the hammer has a resilient element on the first side and / or the second side to promote or retard force imbalance.

14. 14. An actuation trigger as claimed in any preceding claim, wherein the hammer is urged back to or towards the first position by at least part of the return of high pressure actuation fluid to the dosing valve or the trigger chamber.

15. An actuation trigger as claimed in any preceding claim, wherein the hammer is actuated by pressure in the actuation chamber to slow its continued movement towards the dosing valve.

16. The operating load is: a piston trapped within the working chamber; or or a projectile that is not trapped and is ejected from the working chamber; An actuation trigger according to any preceding claim, wherein the actuation trigger is a pressure wave within the actuation chamber that performs work in an otherwise normal manner.

17. An actuation trigger according to any preceding claim, wherein the high pressure actuation fluid is a compressible or incompressible fluid.

18. An actuation trigger as claimed in any preceding claim, wherein the high pressure actuation fluid is in the range of 15 bar to 100 bar.

19. An actuation trigger as claimed in any preceding claim, wherein the fluid is a gas.

20. a dosing chamber holding a charge of high pressure actuating fluid received from a high pressure source; a dosing valve that is biased closed to seal the dosing chamber from the actuation chamber and retain a charge in the dosing chamber; a hammer actuated by a piston having a driven chamber on a first side of the piston and a trigger chamber on a second side of the piston sealed from the first side of the piston, the driven chamber receiving high pressure actuation fluid directly or indirectly from the high pressure source; a trigger valve selectively supplying high pressure actuating fluid to or releasing high pressure actuating fluid from the trigger chamber; having or including When the hammer has high pressure hydraulic fluid in both the driven chamber and the trigger chamber, the hammer is held in a first position by a force imbalance, and when high pressure hydraulic fluid is released from the trigger chamber, the hammer is driven to or toward a second position toward the trigger chamber; When the hammer is driven to or toward the second position, it strikes the dosing valve, unseating the dosing valve and opening the dosing chamber and the actuating chamber, thereby allowing the charge to enter the actuating chamber and do work therein.

21. 21. The apparatus of claim 20, wherein the force imbalance results from a larger acting area of ​​high pressure actuating fluid on a trigger chamber side of the piston than on a driven chamber side of the piston.

22. 22. The device of claim 20 or 21, wherein the trigger valve is a sliding spool valve.

23. the trigger valve selectively releases high pressure actuating fluid from one of the "actuating chambers" - the dosing chamber, the driven chamber, or the trigger chamber - into the ambient environment, or supplies high pressure actuating fluid directly or indirectly from the high pressure source to one of the "actuating chambers" - the dosing chamber, the driven chamber, or the trigger chamber - to activate the device; The trigger valve has at least two positions: a. a first valve position that directly or indirectly supplies the high pressure source to the operating chamber to enable operation, wherein the trigger valve is: i. Open the supply to the driven and trigger chambers; ii. opening the supply to said dosing valve and closing any vent path therefrom; b. a second valve position that activates the device and closes off the supply from said high pressure source, wherein said trigger valve: i. closing off the supply to the device, in particular to the dose chamber and the trigger chamber; ii. venting the trigger chamber to the ambient environment; 23. The device according to any one of claims 20 to 22, comprising:

24. The trigger valve has a third valve position that renders the device safe, wherein the trigger valve: a. closing off the supply to the dose chamber and the trigger chamber; b. Venting the dosing chamber; and c. venting the trigger chamber; Apparatus according to any one of claims 20 to 23.

25. 25. The apparatus of claim 24, wherein the high pressure actuation fluid is prevented from exiting the high pressure source when the trigger valve closes the supply to the apparatus.

26. A device according to any one of claims 20 to 25, wherein the trigger chamber, when supplied, is filled before the dosing chamber.

27. 27. The device of any one of claims 20 to 26, wherein the hammer slides along a first sliding axis and the dosing valve slides along a second sliding axis.

28. 28. The apparatus of claim 27, wherein the first sliding axis and the second sliding axis are at least parallel and concentric.

29. 29. Apparatus according to any one of claims 20 to 28, wherein the dosing valve is an annular ring having an annular ring sealing surface sealing the dosing chamber from the actuation chamber.

30. 30. A device according to any one of claims 20 to 29, wherein the dosing valve is spring biased closed.

31. 31. Apparatus according to any one of claims 20 to 30, wherein the hammer comprises a resilient element on the first side and / or the second side to promote or retard force imbalance.

32. 32. A device according to any one of claims 20 to 31, wherein the hammer is urged back to or towards the first position by at least part of the return of high pressure hydraulic fluid to the trigger chamber.

33. The job is a load being a piston trapped in said working chamber, or a load that is not trapped and is a projectile ejected from said working chamber, or a load being a pressure wave in said working chamber that performs work in other ways, 33. An apparatus according to any one of claims 20 to 32, which is or acts on a load.

34. An apparatus according to any one of claims 20 to 33, wherein the high pressure working fluid is a compressible fluid.

35. Apparatus according to any one of claims 20 to 34, wherein the high pressure working fluid is in the range of 15 bar to 90 bar.

36. An apparatus according to any one of claims 20 to 35, wherein the high pressure working fluid is a gas.

37. A discharge valve is provided. a working load that performs work in or from the working chamber is driven from a first end of the working chamber to or towards an opposite second end of the working chamber using high pressure working fluid to a back surface of the working load; a return chamber in fluid communication with the working chamber, the return chamber receiving fluid pressure from a front side of the working load, the return chamber being fluidly connected to the working chamber, the return chamber being fluidly connected to the working load, the return chamber being fluidly connected to the second end; an operating surface of the exhaust valve fluidly connected to the return chamber, the exhaust valve adapted to open as a result of fluid pressure in the return chamber acting on the operating surface of the exhaust valve, the exhaust valve, when opened, allowing high pressure working fluid in the working chamber present at a rear surface to be discharged from the working chamber to a location of lower pressure, the high pressure working fluid passing through the exhaust valve and being discharged via a side wall of the working chamber; 37. Apparatus according to any one of claims 20 to 36, thus creating a pressure differential from the front to the rear and therefore returning the working load from the second end to or towards the first end.

38. 1. A method of operating a device, comprising: charging the dosing chamber with a charge of high pressure actuation fluid; charging a driven chamber on a first side of the hammer with high pressure hydraulic fluid; charging a trigger chamber on a second side of the hammer with high pressure hydraulic fluid, the first and second sides being separated by a piston operatively connected to the hammer, the hammer being held in a first position by a force imbalance; releasing a high pressure flow actuator from the trigger chamber to drive the hammer to or toward a second position; actuating a dosing valve by impacting the hammer on the dosing valve when the hammer is at or towards the second position, unseating the dosing valve from a sealing position that seals the dosing chamber from the actuation chamber to an open position, thereby allowing the charge to enter the actuation chamber and do work; 10. A method comprising or including:

39. 39. The method of claim 38, wherein the force imbalance is at least partially imparted or retarded by a biasing means such as a spring.

40. 40. A method according to claim 38 or 39, comprising returning the hammer to or towards a first position at least in part by the dosing valve acting on a portion thereof or by the return of high pressure actuation fluid to the trigger chamber.

41. A method according to any one of claims 38 to 40, wherein the high pressure working fluid is supplied directly or indirectly from a high pressure source.

42. 42. The method of claim 41, comprising charging the driven chamber directly or indirectly from the high pressure source.

43. 43. A method according to claim 41 or 42, comprising selectively loading or unloading the trigger chamber and the dose chamber via a trigger valve.

44. 44. The method of claim 43, wherein the trigger valve is a sliding spool valve.

45. the trigger valve selectively releases high pressure actuating fluid from one of the "actuating chambers" - the dosing chamber, the driven chamber, or the trigger chamber - into the ambient environment, or supplies high pressure actuating fluid directly or indirectly from the high pressure source to one of the "actuating chambers" - the dosing chamber, the driven chamber, or the trigger chamber - to activate the device; The trigger valve has at least two positions: a. a first valve position in which the high pressure source directly or indirectly supplies the operating chamber to an operable state, wherein the trigger valve is: i. opening the supply to said dosing chamber and closing any vents therefrom; ii. Opening the supply to any other chambers and preparing to open but not actuating said dosing valves; b. a second valve position that activates the device and closes off the supply from the high pressure source, wherein the trigger valve: i. closing off the supply to the device including the dosing chamber and the trigger chamber; ii. enabling the operating chamber to actuate the opening of the dosing valve; 45. The method of claim 43 or 44, comprising:

46. The trigger valve has a third valve position that renders the device safe, in which the trigger valve: a. shutting off the supply to the dispensing chamber; and b. Ventilate other rooms; 46. ​​The method according to any one of claims 43 to 45.

47. 47. A method as claimed in any one of claims 41 to 46, wherein when the dosing valve is open to communicate the dosing chamber with the actuation chamber, there is no supply from the high pressure source to the dosing chamber, whether via the trigger valve or otherwise.

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