Abstract: A head for a peristaltic pump that may be used for delivering ink to a flexographic printing press includes a housing and a roller assembly. The housing is adapted to receive a flexible tube. The housing has a curved wall and a clamp. The clamp secures the flexible tube within the housing. The roller assembly is rotatable within the housing. The roller assembly includes at least two compression rollers and at least one guide roller. The guide rollers are peripherally spaced between the compression rollers where each of them comes into contact with the flexible tube during rotation of the roller assembly. The guide rollers guide the flexible tube to stay centered with the compression rollers and initiate decompression of the flexible tube to return to a partial compression dimension. Fluid is moved through the flexible tube by rotation of the roller assembly.

Abstract: A head for a peristaltic pump that may be used for delivering ink to a flexographic printing press includes a housing and a roller assembly. The housing is adapted to receive a flexible tube. The housing has a curved wall and a clamp. The clamp secures the flexible tube within the housing. The clamp has an open position and a closed position. The clamp is in the open position when the flexible tube is able to move through an entrance and exit in the housing. The clamp is in the closed position where a first section of the flexible tube is secured in the entrance and a second section of the flexible tube is secured in the exit. The first and second sections are secured where they are not able to be pulled into the housing but are able to gradually slip out of the housing allowing the head to pump in both directions. The roller assembly is rotatable within the housing. The roller assembly rotates about an axis through the housing. The axis is coaxial to the curved wall in the housing.

Abstract: An air spring has pair of spaced end members for mounting the spring at spaced locations on a structure. A flexible sleeve of elastomeric material is sealingly engaged with the end members and forms a pressurized fluid chamber therebetween. A post is mounted on one of the end members and extends into the fluid chamber. A shock absorbing bumper formed of a high strength plastic is snap-fitted on an enlarged top of the post. A plurality of circumferentially arranged flexible fingers define an opening in a base of the bumper, and are snap-fitted over the enlarged top of the post which extends into the opening and seat into an annular undercut formed in the post beneath the enlarged top. The snap-fitted plastic bumper replaces the heretofore used elastomeric bumper.

Abstract: A circuit for driving a power transistor that forms a part of an inverter circuit used in motor control in which the circuit is switched at high voltages. The motor drive circuit isolates and amplifies a control signal so as to operate the power switching transistors. The base drive circuit employs two characteristics of power transistors to derive maximum protection and maximum performance simultaneously. This control is accomplished by sensing both the collector-to-emitter voltage of the power transistor as well as the base-to-emitter voltage thereof. In an alternate embodiment described herein, a feedback circuit is also provided sensitive to collector-to-emitter voltage for shortening the try-time associated with the power transistor.

Abstract: A circuit for driving a power transistor that forms a part of an inverter circuit used in motor control in which the circuit is switched at high voltages. The motor drive circuit isolates and amplifies a control signal so as to operate the power switching transistors. The base drive circuit employs two characteristics of power transistors to derive maximum protection and maximum performance simultaneously. This control is accomplished by sensing both the collector-to-emitter voltage of the power transistor as well as the base-to-emitter voltage thereof.