A piston engine may include a clearance gap between a piston assembly and a cylinder. The piston may be configured to translate in a bore of the cylinder. The clearance gap between the piston assembly and the bore may be actively or passively controlled. A control system may provide one or more adjustments based on, for example, a detected temperature, pressure, flow rate, work metric, and/or other indicator. The adjustments may include, for example, adjusting a cylinder liner, adjusting a flow through a bearing element, adjusting a coolant flow, adjusting a heat pipe property, and/or other adjustments. One or more auxiliary systems may be used to provide the adjustments.

A piston engine may include a clearance gap between a piston assembly and a cylinder. The piston may be configured to translate in a bore of the cylinder. The clearance gap between the piston assembly and the bore may be actively or passively controlled. A control system may provide one or more adjustments based on, for example, a detected temperature, pressure, flow rate, work metric, and/or other indicator. The adjustments may include, for example, adjusting a cylinder liner, adjusting a flow through a bearing element, adjusting a coolant flow, adjusting a heat pipe property, and/or other adjustments. One or more auxiliary systems may be used to provide the adjustments.

A system including a combustion engine is disclosed. The combustion engine includes a first cylinder orientated along a first axis. The combustion engine also includes a first piston, fitted within the first cylinder, to move in reciprocating motion by alternately moving in a first linear direction along the first axis responsive to a first power stroke or a second linear direction along the first axis responsive to a second power stroke. The combustion engine includes a tensile band affixed to a first end and a second end of the first piston. The first piston is to exert a first tensile force on the tensile band in the first linear direction in response to the first power stroke. The first piston is to exert a second tensile force on the tensile band in the second linear direction in response to the second power stroke.

A gas cylinder actuator with overtravel safety device, comprising a tubular jacket for gas containment, which is closed hermetically at one end by a bottom provided with a gas filling valve and at the opposite end by a head portion, which is provided with a hole for the passage of a stem with a piston, the jacket, the bottom and the piston forming the gas expansion and compression chamber. The head portion comprises an annular body, which is fixed internally to the jacket, and is provided with a central hole for the passage of the stem with the interposition of dynamic sealing elements, static sealing elements being interposed between the annular body and the jacket and an element for controlling the descending motion of a slider of a press with which the actuator is associated being provided and protruding from the annular body or from the jacket, the control element being preset to selectively move or break or deform in order to break or deform or render ineffective in general the static and dynamic sealing elements.

A bumper sized to fit a cylinder of a fastener driving tool includes a side profile of the bumper defined by a plurality of flat regions and a plurality of convex regions around an outer periphery of the bumper. Included in the bumper are an inner peripheral surface and an outer peripheral surface. The flat and convex regions are disposed on the outer peripheral surface of the bumper in an alternating pattern.

A bumper sized to fit a cylinder of a fastener driving tool includes a side profile of the bumper defined by a plurality of flat regions and a plurality of convex regions around an outer periphery of the bumper. Included in the bumper are an inner peripheral surface and an outer peripheral surface. The flat and convex regions are disposed on the outer peripheral surface of the bumper in an alternating pattern.

A cushion mechanism for decelerating a piston rod includes a holder fastened to an end surface of a cylinder portion fitted with an inner peripheral surface of a cylinder tube, a plurality of fastening bolts for fastening the holder to the cylinder portion, an annular entry portion provided on the piston rod and advancing into the holder and the cylinder portion in the vicinity of the stroke end, a cushion passage formed by penetrating at least one of the plurality of fastening bolts and allowing a working chamber and a discharge port to communicate with each other and leading a working fluid in the working chamber to a discharge port, and an orifice portion provided on the cushion passage and applying resistance to a flow of the working fluid.

A cushion mechanism for decelerating a piston rod includes a holder fastened to an end surface of a cylinder portion fitted with an inner peripheral surface of a cylinder tube, a plurality of fastening bolts for fastening the holder to the cylinder portion, an annular entry portion provided on the piston rod and advancing into the holder and the cylinder portion in the vicinity of the stroke end, a cushion passage formed by penetrating at least one of the plurality of fastening bolts and allowing a working chamber and a discharge port to communicate with each other and leading a working fluid in the working chamber to a discharge port, and an orifice portion provided on the cushion passage and applying resistance to a flow of the working fluid.

A bumper sized to fit a cylinder of a fastener driving tool includes a side profile of the bumper defined by a plurality of flat regions and a plurality of convex regions around an outer periphery of the bumper. Included in the bumper are an inner peripheral surface and an outer peripheral surface. The flat and convex regions are disposed on the outer peripheral surface of the bumper in an alternating pattern.

A bumper sized to fit a cylinder of a fastener driving tool includes a side profile of the bumper defined by a plurality of flat regions and a plurality of convex regions around an outer periphery of the bumper. Included in the bumper are an inner peripheral surface and an outer peripheral surface. The flat and convex regions are disposed on the outer peripheral surface of the bumper in an alternating pattern.