Miller Fluid Power Corporation

John F Bowbin

Abel E Kolchinsky

Raymond L Ghislain

Ming Liu

Wayne M Davis

Stephen K McDaniel

Locking apparatus for a piston and cylinder device includes a locking plunger connected to the piston and disposed between the piston and an end cap of the piston and cylinder device. The locking plunger includes a sleeve which carries a plurality of radially movable ball bearings. As the piston is moved toward an extreme position of the device, the ball bearings contact a spring loaded locking plug disposed in the head of the device, thereby moving the plug away from a first position. The piston and locking plunger continue to move the locking plug away from the first position until the balls are aligned with a circumferential groove or channel in the head. At this point the locking plug is moved to the first position under spring force, in turn moving the ball bearings radially outward into engagement with the channel or groove. The piston and piston rod of the device are thereby locked in position in the absence of fluid pressure. The locking plug includes surfaces against which pressurized fluid acts at the beginning of a return stroke to move the plug away from the first position and release the ball bearings from the channel. The piston is thereby unlocked and is free to move toward the other extreme position of the device.

Cylinder locking apparatus

An expandable cushion plunger for use with a fluid pressure driven piston and cylinder device includes a cushion sleeve mounted on a piston rod in floating relation thereto, and having a skirt, the interior of which is exposed to the cushioning fluid within the cylinder. As the piston nears the end of its stroke, the sleeve begins to enter a fluid exit port, trapping fluid between the piston and the cylinder head, which will slow and cushion the piston travel as it approaches the cylinder head. As the sleeve continues to enter the fluid exit port, the pressure of the trapped fluid increases due to the smaller size of the annular orifice between the sleeve and the port as compared with the port size. The cushion sleeve may expand under influence of increased pressure, further restricting the flow of pressurized fluid through the annular orifice to provide smooth deceleration of the piston as it reaches the end of its stroke and comes to rest against the cylinder head without undesirable impact.

Expandable cushion plunger for piston and cylinder devices

A hydraulic snubber device arranged for facilitated servicing of a secondary seal thereof. A bushing removably mounted to the head of the device cooperates therewith to retain a split annular seal element in sealed association with a piston rod extending outwardly therethrough. A bushing is movable on the rod sufficiently to expose the seal for selective removal and installation when desired. The snubber is adapted for use in a radioactive environment wherein the split seal may suffer degradation such as from radiation and permits the replacement of the seal without disconnecting elements connected to the end of the piston rod so as to provide minimum downtime in servicing the installation.

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Elmhurst, IL, United States of America

John F Bowbin