A method for processing an inner wall of a cylinder of an internal combustion engine includes providing a cylinder and processing an inner wall of the cylinder. The cylinder extends along a cylinder axis. The inner wall of the cylinder is processed in such a manner that at least one first structural region and one second structural region are formed along the cylinder axis. A geometry of the first structural region differs in design from a geometry of the second structural region.

A piston (6) is hermetically inserted via a sealing member (7) in a cylinder hole (2) provided in a housing (1) so that the piston (6) is movable in an up-down direction. A communication passage (21) provided in an inner peripheral wall of the cylinder hole (2) is communicatively connected to a lock-side supply and discharge passage (13) through which pressurized oil is supplied to and discharged from a lock chamber (11) of the housing (1). An opening area (S.sub.1) of the communication passage (21) is designed to be smaller than an opening area (S.sub.2) of the lock-side supply and discharge passage (13). When the piston (6) is caused to move for releasing from a raised position to a lower limit position, the sealing member (7) is lowered from the raised position beyond the communication passage (21), to open communication between a release chamber (12) in the housing (1) and the lock-side supply and discharge passage (13) via the communication passage (21).

A piston and cylinder assembly of an axial piston machine is disclosed which includes a cylinder having a uniform internal diameter, a cylindrical bushing press-fit against the inner surface of the cylinder and extending at least partially therein, the bushing comprising at least one circumferential groove formed on an outer surface of the bushing against the inner surface of the cylinder, a piston reciprocably disposed within the cylindrical bushing, generating a piston-bushing-interface, the piston and the bushing defining a diametrical clearance therebetween, the diametrical clearance defining a lubrication gap and a fluid-dynamic seal between the piston and the cylindrical bushing.

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.

Passenger restraint systems are provided. The restraint systems can include: a passenger seat supported by a frame; a restraint bar pivotably attached to the frame; and at least one piston operably engaged between the restraint bar and the frame. Restraint system pistons are provided. The pistons can include: a central chamber housing a piston head and rod; a fluid reservoir in fluid communication with the central chamber; and at least one electromechanical valve operable between an open and a closed position. Methods for restraining a passenger within a seat are also provided.

Manually operable piston assemblies are provided that can include a piston head within a cylinder, the piston head separating fluid in the cylinder to define rod-side fluid and head-side fluid. The piston assembly can be configured to operate in at least six positions, including but not limited to a first position of locking retract static; a second position of locking retract extend flow; a third position of locking retract flow; a fourth position of locking extend static; a fifth position of locking extend retract flow; and a sixth position of locking extend flow. Manually operable piston assemblies are also provided that can include a piston head within a cylinder, with the piston head separating fluid in the cylinder to define rod-side fluid and head-side fluid. The manually operable piston assembly can further be configured to operate in at least six positions that include a first position of locking extend static; a second position of extend movement flow; a third position of manual override retract flow; a fourth position of manual override extend flow; a fifth position of locking retract static; and a sixth position of retract movement flow.

Methods for operating a manually operable piston are also provided. The methods can include applying pressure to retract the piston rod and allow head-side fluid to pass through piston head passageway and mix with rod-side fluid. Methods for operating a manually operable piston can also include applying pressure to extend or retract the piston rod and allow head-side fluid to pass through at least one valve and mix with rod-side fluid.

Passenger restraint systems are provided. The restraint systems can include: a passenger seat supported by a frame; a restraint bar pivotably attached to the frame; and at least one piston operably engaged between the restraint bar and the frame. Restraint system pistons are provided. The pistons can include: a central chamber housing a piston head and rod; a fluid reservoir in fluid communication with the central chamber; and at least one electromechanical valve operable between an open and a closed position. Methods for restraining a passenger within a seat are also provided.

Manually operable piston assemblies are provided that can include a piston head within a cylinder, the piston head separating fluid in the cylinder to define rod-side fluid and head-side fluid. The piston assembly can be configured to operate in at least six positions, including but not limited to a first position of locking retract static; a second position of locking retract extend flow; a third position of locking retract flow; a fourth position of locking extend static; a fifth position of locking extend retract flow; and a sixth position of locking extend flow. Manually operable piston assemblies are also provided that can include a piston head within a cylinder, with the piston head separating fluid in the cylinder to define rod-side fluid and head-side fluid. The manually operable piston assembly can further be configured to operate in at least six positions that include a first position of locking extend static; a second position of extend movement flow; a third position of manual override retract flow; a fourth position of manual override extend flow; a fifth position of locking retract static; and a sixth position of retract movement flow.

Methods for operating a manually operable piston are also provided. The methods can include applying pressure to retract the piston rod and allow head-side fluid to pass through piston head passageway and mix with rod-side fluid. Methods for operating a manually operable piston can also include applying pressure to extend or retract the piston rod and allow head-side fluid to pass through at least one valve and mix with rod-side fluid.

A fluid end for a fracturing pump includes a plurality of segments coupled together along a discharge axis, each segment of the plurality of segments having a plurality of suction bores. The fluid end also includes respective interfaces between segment pairs formed by adjacent segments of the plurality of segments, the interfaces coupling the segment pairs together. The fluid end further includes respective access areas proximate the respective interfaces, the respective access areas configured to provide access for mechanical couplings to join the segment pairs together.

Disclosed are lock mechanisms for latch assemblies of vehicle compartment hoods, methods for making or using such lock mechanisms, and motor vehicles equipped with a multi-pull latch and lock system for releasably locking a hood assembly. A lock mechanism includes a gear that couples a closure latch to a latch release mechanism. The gear moves between a latched position, whereat the closure latch secures the closure in a closed position, and an unlatched position, whereat the gear transfers activation forces from the release mechanism to disengage the closure latch from the closure. A pawl is movable between a locked position, whereat the pawl engages and locks the gear in the latched position, and an unlocked position, whereat the pawl disengages the gear. An actuator is operatively engaged with a vehicle door to automatically move the pawl to the unlocked position responsive to movement of the door to an open position.

Proposed is manufacturing method for a hybrid tube, the method including the step of deriving an optimal ratio between a metal tube and a composite material layer when manufacturing the hybrid tube in which the composite material layer is formed on an outer circumferential surface of the metal tube in order to reduce the weight of an existing metal tube such as a cylinder tube of a hydraulic cylinder. In manufacturing a hybrid tube, it is possible to derive an optimal ratio between heterogeneous materials that can achieve weight reduction while satisfying a target buckling load, thereby making it possible to reduce the weight of tubes of metal materials and apparatuses related to such tubes.

A hydraulic cylinder with a load distribution nut connected to an end cap reduces fatigue experience by the end cap portion of the cylinder. The load distribution nut separates the axial load generated in the system from a single to multiple load paths. By introducing additional load paths, the load experienced by the traditional load path is reduced. Additionally, the load experienced by the end cap can be tailored by modifying the design of the load distribution nut and end cap. By either increasing or decreasing the surface area of the load distribution nut the axial load reduction on the end cap is correspondingly decreased or increased.