Methods, apparatus, systems and articles of manufacture are disclosed that produce a pneumatic actuator end cap having an integral volume booster. An example pneumatic actuator end cap includes a first cavity to provide a first fluid passageway to receive a pressurized fluid from a source external to the pneumatic actuator end cap, a second cavity to provide a second fluid passageway to route the pressurized fluid to an internal chamber of a pneumatic actuator in which a piston is disposed, and a third cavity containing a fluid valve to control a flow of the pressurized fluid between the first fluid passageway and the second fluid passageway.

Methods, apparatus, systems and articles of manufacture are disclosed that produce a pneumatic actuator end cap having an integral volume booster. An example pneumatic actuator end cap includes a first cavity to provide a first fluid passageway to receive a pressurized fluid from a source external to the pneumatic actuator end cap, a second cavity to provide a second fluid passageway to route the pressurized fluid to an internal chamber of a pneumatic actuator in which a piston is disposed, and a third cavity containing a fluid valve to control a flow of the pressurized fluid between the first fluid passageway and the second fluid passageway.

An accelerator-equipped pneumatic cylinder includes a cylinder block, a switch valve, and pneumatic cylinder. The cylinder block defines therein a piston chamber and a pressure chamber. The switch valve has a valve seat installed in the cylinder block and between the piston chamber and the pressure chamber. A controller is installed in the valve seat for controlling the piston chamber and the pressure chamber to be communicated with each other or not. The pneumatic cylinder has a piston portion received in the piston chamber, and has a shaft portion extending outward from the cylinder block. At a moment when a channel is made opened by the controller and the piston chamber and the pressure chamber come into communication with each other, the piston portion is pushed by a pressure medium at an accelerated speed, so that the shaft portion is pushed outside the piston chamber at the accelerated speed.

A piston assembly including a shaft having a piston arrangement. The piston arrangement has a retract-area on one side and a extend-area on the opposite side. The retract-area is larger than the extend-area so that when fluid exerts a force on the retract-area the piston arrangement generates and applies a retract force to the shaft. Upon release of the fluid pressure to the retract-area and application of the fluid pressure to the extend-area the piston arrangement generates and applies an extend force to the shaft. The retract force is greater than or equal to the extend force.

A piston assembly including a shaft having a piston arrangement. The piston arrangement has a retract-area on one side and a extend-area on the opposite side. The retract-area is larger than the extend-area so that when fluid exerts a force on the retract-area the piston arrangement generates and applies a retract force to the shaft. Upon release of the fluid pressure to the retract-area and application of the fluid pressure to the extend-area the piston arrangement generates and applies an extend force to the shaft. The retract force is greater than or equal to the extend force.

A cylinder acceleration mechanism includes a buffer tank that supplies and discharges oil to and from a bottom-side line that is connected to a bottom-side chamber of an actuating cylinder, and an inversion lever having an intermediate fulcrum as a rotation axis. The buffer tank includes a buffer chamber with a variable capacity achieved by a seal lid moving back and forth inside of a case, and extends and reduces a length of a coupling rod provided to the seal lid and projects from the case. A bottom-side branching line branched from the bottom-side line is connected to the buffer chamber. The actuating rod of the actuating cylinder and the coupling rod of the buffer tank are coupled to respective ends of the inversion lever. The actuating rod and the coupling rod extend and retract alternately with respect to each other as the inversion lever turns.

A communication path that communicates with a first main pressure chamber is provided in a main piston and a piston rod. A check valve, which opens by being pressed by a booster piston and allows the communication path to communicate with a first sub-pressure chamber when the piston rod reaches a booster start position before a forward stroke end, is disposed in an end portion of the communication path. A plurality of steel balls are disposed in a coupling-member containing chamber formed in the booster piston. An engagement surface and an engagement groove, which engage with the steel balls when the booster piston moves forward due to an action of a pressure fluid supplied to the first sub-pressure chamber 11a through the communication path, are formed in the coupling-member containing chamber and an outer peripheral surface of the piston rod.

Disclosed herein is a three-stage hydraulic actuator. The three-stage hydraulic actuator includes a pressurizing chamber, a distribution chamber and an acceleration chamber. The pressurizing chamber has therein separated spaces respectively charged with compressed gas and compressed oil. The distribution chamber is provided to communicate with the pressurizing chamber and is charged with oil pressurized by the compressed oil charged into the pressurizing chamber. The acceleration chamber communicates with the distribution chamber through a distributing orifice. An acceleration piston is installed in the acceleration chamber and is moved forward when the pressurized oil is supplied from the distribution chamber to the acceleration chamber.

A cylinder acceleration mechanism includes a buffer tank that supplies and discharges oil to and from a bottom-side line that is connected to a bottom-side chamber of an actuating cylinder, and an inversion lever having an intermediate fulcrum as a rotation axis. The buffer tank includes a buffer chamber with a variable capacity achieved by a seal lid moving back and forth inside of a case, and extends and reduces a length of a coupling rod provided to the seal lid and projects from the case. A bottom-side branching line branched from the bottom-side line is connected to the buffer chamber. The actuating rod of the actuating cylinder and the coupling rod of the buffer tank are coupled to respective ends of the inversion lever. The actuating rod and the coupling rod extend and retract alternately with respect to each other as the inversion lever turns.

A communication path that communicates with a first main pressure chamber is provided in a main piston and a piston rod. A check valve, which opens by being pressed by a booster piston and allows the communication path to communicate with a first sub-pressure chamber when the piston rod reaches a booster start position before a forward stroke end, is disposed in an end portion of the communication path. A plurality of steel balls are disposed in a coupling-member containing chamber formed in the booster piston. An engagement surface and an engagement groove, which engage with the steel balls when the booster piston moves forward due to an action of a pressure fluid supplied to the first sub-pressure chamber 11a through the communication path, are formed in the coupling-member containing chamber and an outer peripheral surface of the piston rod.