Abstract: A linear actuator is provided having a housing with a bore having at least first and second portions extending therethrough. The second portion has a polygonal geometry with substantially rounded corners having at least one planar bearing surface. A shaft is in sliding engagement with the first portion of the bore, and a piston member is operatively coupled to the shaft. The piston member has a mating geometry to the second portion of the bore, wherein the piston member is in sliding engagement with the second portion of the bore. An anti-rotation member is coupled to the piston member or shaft and has a generally D-shaped geometry with a planar anti-rotation bearing surface. Contact between the anti-rotation member and the housing is limited to a sliding engagement between the anti-rotation bearing surface and one of the at least one bearing surfaces based on an orientation of the anti-rotation member.

Abstract: A linear actuator is provided having a housing with a bore having at least first and second portions extending therethrough. The second portion has a polygonal geometry with substantially rounded corners having at least one planar bearing surface. A shaft is in sliding engagement with the first portion of the bore, and a piston member is operatively coupled to the shaft. The piston member has a mating geometry to the second portion of the bore, wherein the piston member is in sliding engagement with the second portion of the bore. An anti-rotation member is coupled to the piston member or shaft and has a generally D-shaped geometry with a planar anti-rotation bearing surface. Contact between the anti-rotation member and the housing is limited to a sliding engagement between the anti-rotation bearing surface and one of the at least one bearing surfaces based on an orientation of the anti-rotation member.

Abstract: A linear actuator is provided comprising a housing, a rectangular elongate shaft operably coupled to the housing, and a scraper assembly. The shaft has a hardened bearing surface in sliding engagement with a hardened bearing surface of the housing, thus providing a hard-on-hard bearing between the shaft and housing, wherein the shaft is prevented from rotating with respect to the housing. The scraper assembly comprises first and second resilient members positioned within a recess of the housing, wherein one or more scraper blades are disposed between the first and second resilient members. A retaining member coupled to the housing generally compresses the first and second resilient members within the recess, therein biasing a scraping edge of the one or more scraper blades against the shaft bearing surface, wherein the retaining member, one or more scraper blades, and the first resilient member are operable to clear debris from elongate shaft.

Abstract: A locking mechanism for a locating and clamping fixture is provided, wherein the locking mechanism comprises a drive pin that is linearly positionable along a first axis. The drive pin comprises a driver portion and a driven portion, wherein the driver portion is coupled to a piston of the fixture and the driven portion is coupled to a clamping arm of the fixture. The driver portion of the drive pin further comprises an annular groove, wherein one or more rollers are associated with the annular groove of the drive pin and a body of the fixture. The one or more rollers are operable to generally maintain a position of the clamping arm upon a loss of a driving force to the driver portion via an interface between the one or more rollers, the drive pin, and the body.

Abstract: A rotation-preventing slide is provided for a linear actuator which includes a housing which defines an internal bore and a piston-rod assembly which linearly moves within the internal bore in response to fluid pressure. The rotation-preventing slide is connected to and moves with the piston-rod assembly within a guide defined by the housing and has a geometry (e.g., polygonal, rectangular, square) which prevents rotation of the piston-rod assembly. The slide may include a bearing block and an attachment member which extends through an opening in the bearing block and which is removably attached to the piston-rod assembly whereby the slide's bearing surface (e.g., the bearing block) may be easily replaced. The guide may be a guide slot position parallel to, but axially offset from, the internal bore.

Abstract: The present invention is directed to a cushioning apparatus for a pneumatic device. The cushioning apparatus generally comprises a body, wherein a piston and cylinder reside therein, wherein the piston is operable to translate along a first axis. A first port associated with a first end of the cylinder is in fluid communication with an interior portion of the cylinder through a first cushioning hole, and a second port associated with a second end of the cylinder is in fluid communication with the interior portion through a second cushioning hole.

Abstract: The present invention is directed to a locating and clamping fixture for locating and clamping a workpiece, wherein the fixture comprises a generally hollow body and a floating clamping arm. A first cam follower is located within the body, and a drive pin comprising a second cam follower and having a first axis associated therewith is moveable within the body along the first axis. The floating clamping arm comprises a first cam surface, a second cam surface, and a gripping portion, wherein the first cam surface and the second cam surface are operable to respectively engage the first cam follower and the second cam follower. Upon an application of a driving force by the drive pin, the clamping arm is operable to rotate and linearly translate with respect to the body via a translational movement of the drive pin along the first axis, wherein the gripping portion of the clamping arm is operable to extend over the workpiece and to clamp the workpiece to the body.

Abstract: A piston and cylinder assembly for use in actuating a locating pin for sheet metal provides stability for a pin mounted thereon against side to side movement and rotation. To this end the assembly includes a cylinder body assembly with an internal bore and a piston axially slidable within the bore. A piston rod is connected with the piston, and the rod has a free end for connection of a sheet metal locating pin. A first guide surface is formed within the cylinder body assembly and a second guide surface is formed on one of the piston and piston rod, the first and second guide surfaces cooperating to prevent rotation of the piston and piston rod as the piston and piston rod slide axially with respect to the cylinder body assembly. The first and second guide surfaces preferable are internal and external splines. First and second bearings are connected to the cylinder body assembly and support the piston rod for straight line movement. The first and second bearings being located on opposite sides of the piston.

Abstract: A parallel gripper for use in automated material handling is designed for use both in a clean room environment and in an abrasive atmosphere. The gripper includes a housing with air operated pistons which drive slides mounted on the outside of the housing. The pistons are connected to the slides by drive bars that pass through purge chambers. These chambers may be held at a pressure that is above or below the ambient depending on the environment. A seal is placed between the slide and the housing, the seal being made of a material that has a low coefficient of friction and which will cold flow under pressure, for example, TEFLON. The gripper is assembled and the purge chamber pressurized so that normally no air passes by the seal. When a particle of dirt gets under the seal, the pressure difference across the seal drives the dirt in the desired direction: outward when the gripper is used in an abrasive environment or inward when the gripper is used in a clean room environment.

Abstract: A device for moving members into engagement with a workpiece includes a housing having surfaces for defining a chamber and first and second pistons located in the chamber movable toward and away from each other. A first connector connects the first piston to a member movable into engagement with the workpiece and extends through a first opening in the housing. A second connector connects the second piston to another member movable into engagement with the workpiece and extends through a second opening in the housing. Fluid pressure is applied to opposite sides of the first and second pistons to move the first and second pistons toward and away from each other. Debris is removed from the first and second openings in the housing through which the first and second connectors extend.

Abstract: A device for moving gripping jaws into engagement with a workpiece comprises a housing defining a chamber and first and second ends for closing opposite ends of the chamber. First and second pistons are located in the chamber and are movable toward and away from each other. The first and second pistons are connected to the gripping jaws. Fluid pressure is applied to opposite sides of the first and second pistons to move the first and second pistons toward and away from each other. A rod extending along a longitudinal axis of the housing ensures synchronous movement of the first and second pistons. The rod and the first and second pistons have a driving interconnection which effects rotation of the rod in one direction when the first and second pistons move toward each other and in an opposite direction when the first and second pistons move away from each other. Axial end surfaces of the rod engage the first and second housing ends.

Abstract: A continuous form tractor drive is disposed out of the way and out of sight below the printing platen (which itself may be capable of feeding individual forms to a print station). The mechanical paper handling and printing mechanism is affixed to the upper portion of a hinged housing with the continuous form tractor drive mechanism depending therefrom such that, when rotated upwardly and rearwardly to an opened position, easy access is provided for loading paper into the continuous form paper drive.

Abstract: A printer is provided with a controllable bail located between a print station and a downstream paper tear-off station. Upon occurrence of a first control signal, a printed portion of the paper is advanced to a desired tear-off position adjacent the tear-off station. Thereafter (after a predetermined time delay or after operator switch actuation), the paper is retracted to a new first print line position at the print station. The intermediately located bail is released at least after the leading edge of the paper is retracted thereunder and until sufficient paper is again advanced (e.g. during new printing operations) to ensure that paper is again located between the printing platen and the bail before the bail is re-engaged.