Abstract: A mast and carriage assembly for an industrial truck which includes a stationary upright assembly (12) a movable upright assembly (14) and a telescopic cylinder (18) which is suspended between the stationary upright assembly and a load carriage (16) by a system of reeved load chains (94). The cylinder and its extensible ram assembly (69) are guided for vertical movement relative to the upright assemblies, and stop members (100) mounted on the load carriage are engageable with guide members (80) associated with the ram assembly to limit vertical movement of the load carriage relative to the ram assembly.

Abstract: A load support and shuttle combination. The load support (20) is in the form of a central beam (24) disposed fore and aft in a storage bay (22) on top of which are mounted a plurality of spaced apart V-shaped load support members (26), the outer ends of which are bent downward to a substantially horizontal position. The shuttle includes a pair of space apart rails (46) which straddle the beam (24). A plurality of spaced load supporting finger members (48) extend inwardly and downwardly from the rails and are sized and shaped such that they fit in the spaces between the V-shaped load support members. A load resting on the load support member can be transferred to the shuttle by inserting the load supporting finger members into a storage bay beneath the load support members and then lifting the shuttle to move the finger members through the spaces between the load support members.

Abstract: A support assembly for the seat (32) of an electric lift truck (10) which permits the seat to be pivoted about a vertical support member (24) and slid outward to move the seat clear of the truck's battery compartment (12). The means for pivoting the seat includes a first latch (44) which normally keeps the seat from rotating relative to the support member (24). The seat is mounted on a sliding mounting assembly (30) which allows the seat to be slid outward of the truck, and which also includes a latch assembly (68) for normally maintaining the seat in an operating position.

Abstract: A method and apparatus are disclosed for providing heat conduction between an article being treated in a vacuum and a support member by providing a gas under pressure of about 0.5 to 2.0 Torr between the article and the support member. The method and apparatus are described for use in a semiconductor wafer ion implantation system wherein the wafer is clamped to the support member which is cooled. A seal can be provided between the wafer and the support member adjacent the periphery of the article.

Abstract: A suspension hook assembly for a hoist in which the shank of the hook is received between an assembled pair of half-cylindrical members held together by a ring. A pin member received between spaced frame members of the hoist extends through aligned holes in the assembled half-cylindrical members, and the ring is positioned axially between the pin and outwardly directed projections formed on the half-cylindrical members. The hook then pivots about a first axis through its shank, and the hook assembly pivots about a second, perpendicular, axis through the pin.

Abstract: A relief valve, particularly adapted for use on racing car tires, which pops open to relieve at a set pressure and then reseats at a pressure slightly lower than the opening pressure. The valve includes a diaphragm (28) a diaphragm retaining plate (36) which has a resilient sealing element (39) molded or otherwise attached to it, a valve seat attached to the center of the diaphragm, and a compression spring (26) acting on the diaphragm to bias the valve seat against the resilient sealing element. When the valve pops open against the spring force, the area above the diaphragm is exposed to a venting pressure, via a port formed through the valve seat and through the diaphragm, which is higher than atmospheric and thus adds to the spring force, resulting in a resealing pressure which is slightly less than the opening pressure.

Abstract: A hydraulic fluid storage tank for an industrial vehicle. A small surge tank (44) is mounted on top of a main tank (10) and communicates with the main tank via a drain back hole (49) formed in the top of the main tank. A first breather tube (46), having one end opening within the surge tank, extends directly into the main tank. A second breather tube (48), having one end opening within the surge tank, enters the main tank through the drain back hole, extends along the top of the tank, and opens into the tank at a point substantially rearward of the first vent tube. If, due to movement of the vehicle, one of the breather tubes becomes filled with oil, the other will still function. Oil which momentarily floods one of the breather tubes enters the surge tank and drains back to the main tank via the drain back hole.

Abstract: A combined unloader and check valve for use with a motor driven air compressor (70) in which pressure trapped in the compressor head when the compressor is shut down is unloaded by means of an unloaded valve element (44) which opens a port (26) to unload the head pressure to atmosphere through an exhaust port (62) in response to the closing of a check valve element (34) in the compressor outlet line. When the compressor is operating and the check valve is open, pressure above the unloading valve element keeps the unloading valve element in position to shut off flow through the exhaust port. Air trapped above the unloader valve element when the check valve is initially closed is bled off through a filter element (52). In a preferred embodiment of the invention, the unloader valve element (144) is in the form of a diaphragm. The filter element (52) can be a compressible material to permit adjustment of the bleed rate therethrough by varying the density thereof by means of an adjustable bleed screw (48).

Abstract: An end stop for a link chain hoist (10) in which a ring (28) is received through the opening (22a) of the next-to-last load chain link (20a) on one side of the third last link (20c), with the last load chain link (20b) received in the opening (22a) on the other side of the third last link to force the next to the last link sideways relative to the remainder of the load chain to define an end stop engageable with the chain guide (16) of the hoist.

Abstract: A pressure relief valve (10) including a valve stem (34) having an elastomeric valve element (36) received in a counterbore (38) formed in one end thereof and engageable with a valve seat (32) formed in the body (12) of the valve. An annular channel (58) is formed in the valve body surrounding the valve seat, and the valve element is recessed below the outer edge of the counterbored end of the valve stem, such that a thin, annular wall section (39) defined by the difference between the diameter of the counterbore and the outer diameter (40) of the valve stem, extends downward into the annular channel when the valve is closed.The outer diameter of the counterbored end of the valve stem is substantially smaller than the inner diameter (22) of the main valve chamber to define an annular fluid escape passage (64) and a lip is formed on the valve stem above the counterbored end to guide the valve stem in the main valve chamber.

Abstract: A system for effecting the gradual engagement and disengagement of the clutches of a fluid power shifted transmission for industrial lift trucks. The system includes a selector valve for porting fluid from an engine driven pump to the clutches of the transmission and from the clutches to a system reservoir; the selector valve includes damping means for limiting the rate of change in flow through the valve. The system further includes a control valve which operates to limit the pump outlet pressure at engine speeds above a predetermined maximum and to decrease the pump outlet pressure and therefore the clutch actuation force in response to increases in the force applied by the truck brakes.

Abstract: A multiple function control for an electric lift truck which facilitates moving the truck while the load carriage is being raised or lowered. Two vehicles speeds in forward and reverse can be selected by means of a pair of pushbuttons (34, 36) located on the load carriage lift control handle (32), independent of the normal vehicle travel control (28). Circuit means are provided to prevent simultaneous selection of both forward and reverse drive motor directions and to prevent adverse results from simultaneous operation of the normal vehicle travel control and the pushbutton control.

Abstract: An adjustable support structure for a motor vehicle steering column. The steering column is attached to a first tube which is telescopically received within a second tube attached to the vehicle frame. A releasable wedge member acts between the two tubes to lock the steering column in any one of an infinite number of positions within a selected adjustment range.

Abstract: A pressure and liquid tight compression fitting particularly adapted for attachment to a beverage container. An externally threaded body portion of the fitting is inserted through a wall of the container and is clamped to the wall by means of a nut. A first pressure seal is effected by an O-ring received in a groove formed in the face of the nut in contact with the container wall. A first liquid seal is effected by a thin lip formed at the outer edge of the nut, beyond the O-ring. A combined second pressure seal and second liquid seal is effected by interfitting tapered sections of the body portion and the nut beyond the threaded connection between the body and the nut.

Abstract: A control mechanism for the lift cylinder of an electric lift truck. A first pump motor is energized by the closing of a first switch in response to movement of the lift valve spool toward the lift position. A second pump motor is energized when the lift valve spool is in its full lift position and a bending moment is applied to the control rod controlling the lift valve spool of sufficient magnitude to elastically deflect the control rod into closing engagement with the switch.

Abstract: A method and apparatus for installing a traveling hose array in a mobile tree harvester. One end of the hose array travels with the extensible delimbing head of the harvester, and a hose reeving system including a movable trolley is provided to maintain a constant hose length.The hoses are pretensioned at assembly, and a reeved cable system is provided to maintain tension on the hose array and to return the hose array upon retraction of the delimbing head.

Abstract: Low pressure in a vehicle tire is detected by an electronic system which compares the difference in phase between two cyclic signals and produces an output signal having a negative going pulse and a positive going pulse for each revolution of the tire. Each negative going pulse represents a decrease in phase between the two signals and is generated in response to a shorted coil passing through an electromagnetic field produced by an induction coil in a parallel resonant circuit which produces the second of the two signals. The first signal is produced by an oscillator and is used to excite the resonant circuit and as a reference signal. The coil is shorted by a closed switch in the tire when the pressure is normal. Abnormal tire pressure opens the switch and renders the coil ineffective. Each positive going pulse represents an increase in phase between the two signals and is generated in response to a ferrous metal plate passing through the field.

Abstract: A method and apparatus for processing trees in which a clamp holding a severed tree for processing pulls the tree through a set of delimbing blades, while at the same time the blades are moved in the opposite direction along the tree trunk. A system of pulleys and cables driven by a single hydraulic cylinder moves a movable boom and a processing head in one direction relative to a stationary boom, while a clamp assembly is moved in the opposite direction relative to the stationary boom.

Abstract: A valve core having a barrel particularly adapted for use with a fluorocarbon gasket in which the area of the barrel under the gasket is defined by three annular surfaces of successively smaller diameter connected by beveled transition areas. The stepped configuration of the barrel in combination with a tapered valve stem seat provides areas of relatively high unit loading of the gasket against the stem seat bounded by areas of relatively low unit loading.