Abstract: A clamp for handling stacked loads of different sizes has a hydraulic circuit capable of selectively causing closing movement of a pair of clamp arms in synchronized unison with each other and thereafter, automatically in response to resistance to closing movement by one but not the other of the pair of clamp arms, causing unsynchronized closing movement of the other clamp arm. Subsequently, upon opening of the clamp, the hydraulic circuit initially causes opening movement of the previously unsynchronized clamp arm and thereafter, automatically in response to the attainment of synchronized clamp arm positions, causes opening movement of the pair of clamp arms in synchronized unison with each other.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include continuous weight-responsive automatic regulation of the gripping pressure while the load is supported by the clamp, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include continuous weight-responsive automatic regulation of the gripping pressure while the load is supported by the clamp, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include continuous weight-responsive automatic regulation of the gripping pressure while the load is supported by the clamp, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include continuous weight-responsive automatic regulation of the gripping pressure while the load is supported by the clamp, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include continuous weight-responsive automatic regulation of the gripping pressure while the load is supported by the clamp, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include continuous weight-responsive automatic regulation of the gripping pressure while the load is supported by the clamp, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include an automatic limit on the rate of lift of the load during weighing, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include continuous weight-responsive automatic regulation of the gripping pressure while the load is supported by the clamp, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A fluid power load-clamping system includes at least one fluid valve for variably regulating the maximum fluid pressure causing closure of the clamp. Preferably the valve increases the maximum fluid pressure automatically in relation to the measured magnitude of the weight of the load to regulate the load-gripping force. A controller causes the valve to permit a relatively high maximum fluid pressure as the clamp closes toward the load to enable high initial clamp closure speed. Thereafter the valve automatically reduces the maximum pressure as the clamping surfaces close into a predetermined relationship with the load, and then increases the maximum pressure to regulate the gripping force. Other preferable features include continuous weight-responsive automatic regulation of the gripping pressure while the load is supported by the clamp, and compensation of the weight measurement for the longitudinally-extensible position of the lifting mechanism, to maximize the accuracy of the load-weight measurement.

Abstract: A lift truck clamp for handling stacked loads of different sizes has a pair of opposing clamping assemblies, one of which has a pair of clamp arms movable selectively toward and away from the other clamping assembly under the control of a pair of fluid power actuators. A linkage mechanism interconnects the pair of clamp arms so as to permit relative movement therebetween to enable the clamp arms to move asynchronously toward the other clamping assembly. The linkage mechanism includes a stop assembly preventing more than a predetermined misalignment of the pair of clamp arms, and a spring assembly imposing a yieldable biasing force biasing the pair of clamp arms toward alignment with respect to each other.

Abstract: A layer-picking clamp mountable on a truck has clamp arms extending downwardly from and movably mounted to an upper frame section. The clamp arms are linearly movable with respect to the upper frame section in laterally inward and outward directions so that gripping surfaces of the clamp arms retain their substantially vertical orientations as the clamp arms move inward and outward. The upper frame is supported on a first mounting apparatus that is positioned above a second mounting apparatus that supports a load-supporting device. The first mounting apparatus movably supports the upper frame so as to move the upper frame laterally and vertically with respect to the load-supporting device to enable the clamp arms to deposit a load on the load-supporting device. The load-supporting device is capable of supporting a pallet upon which the clamp can deposit the load.

Abstract: A load clamp has two selectively openable and closable opposing clamping assemblies, one of which comprises at least a pair of clamp arms movable separately from each other toward and away from the other clamping assembly. Separate actuators for the respective clamp arms are controlled automatically by a regulator in such a way that the respective closure movements of the arms are simultaneous. A selective adjuster assembly enables the operator to select alternate different maximum magnitudes of clamping force to be imposed by the clamp arms on different loads. An override assembly overrides the regulator to permit nonsimultaneous clamp arm movement, automatically in response to resistance to closure by one of the clamp arms, independently of selective variation of such adjuster assembly.

Abstract: A rotatable load-handling clamp assembly has a rotation-stopping triggering assembly for automatically stopping clamp rotation at one or more predetermined stop positions. A hydraulic motor rotates a rotatable frame having clamp arms thereon with respect to a base. A hydraulic motor control system includes a switch and a set of triggering devices mounted in mutual opposition on the frame and base. The triggering devices are positioned to actuate the switch at the predetermined stop positions, and thereby automatically stop rotation of the hydraulic motor at such positions.

Abstract: A load is gripped between a pair of load-engaging surfaces while the magnitude of any slippage between the load and the surfaces is variably sensed. A slip-correcting system variably predetermines an increase in the grip sufficient at least to decelerate the sensed magnitude of slippage, and the grip is automatically variably increased accordingly. Preferably, the magnitude of slippage sensed is a magnitude of relative movement between the load and the load-engaging surfaces, and preferably the magnitude of relative movement is a time-based magnitude such acceleration. The predetermined increase in the grip resulting from the sensed magnitude of slippage is preferably a predetermined increase in the proximity of the load-engaging surfaces, rather than any particular increase in the gripping force applied by the surfaces. A preferred fluid-powered embodiment of the clamp apparatus is disclosed for use on lift trucks in handling paper rolls and the like.

Abstract: A push-pull slipsheet handler for a forklift truck is capable of utilizing the truck's standard forks for load-supporting purposes, while enabling mounting and demounting of the push-pull assembly and forks in unison with respect to the lift truck carriage. The upstanding portions of the standard forks are suspended from a transverse mounting member affixed to the frame of the push-pull assembly at an elevated position. The mounting member has a pair of fork-supporting surfaces positioned in transversely offset relation to vertically pivotable push-pull links, thereby minimizing forward protrusion of the push-pull assembly in its fully-retracted position despite the mounting of the standard forks on the push-pull frame. The construction also permits side shifting of the push-pull assembly and standard forks as a unit relative to the lift truck carriage.

Abstract: A push-pull slipsheet handler mountable on a standard hook-type lift truck carriage compatibly with load-handling forks mounted on the carriage. The slipsheet handler comprises a push-pull assembly and split platen, both of which receive their vertical support from the load-supporting surfaces of the forks. Attachment of the push-pull assembly to the lower hook-type bar of the carriage provides resistance against fore-and-aft movement of the slipsheet handler. To convert the truck rapidly to a fork-type truck capable of handling standard rigid pallets rather than slipsheets, the platen may be quickly removed leaving the push-pull assembly in place or, alternatively, the push-pull assembly and platen may be removed as an integral unit.

Abstract: A lift truck load handling attachment having a quick-disconnect hook assembly for quick mounting or demounting of the attachment on a lift truck carriage. The hook assembly comprises a hook mounting member fastened to the rearwardly-facing surface of the frame of the load-handling attachment, slideably mounting an upwardly-facing hook for vertical reciprocation of the hook relative to the mounting member. The hook and mounting member respectively have elongate, vertically-oriented interlocking slides for permitting such vertical reciprocation while preventing rearward movement of the hook relative to the mounting member. A locking pin is selectively insertable transversely to limit downward movement of the hook relative to the mounting member, and the vertical slides and pin are located below the engagement surface of the hook when in its engaged position so as to permit direct abutment between the front of the lift truck carriage and rear of the attachment frame.

Abstract: A push-pull slipsheet handler mountable on a standard hook-type lift truck carriage compatibly with load-handling forks mounted on the carriage. The slip-sheet handler comprises a push-pull assembly and split platen, both of which receive their vertical support from the load-supporting surfaces of the forks. Attachment of the push-pull assembly to the lower hook-type bar of the carriage provides resistance against fore-and-aft movement of the slipsheet handler. To convert the truck rapidly to a fork-type truck capable of handling standard rigid pallets rather than slipsheets, the platen may be quickly removed leaving the push-pull assembly in place or, alternatively, the push-pull assembly and platen may be removed as an integral unit.

Abstract: A push-pull slipsheet handler mountable on a standard hook-type lift truck carriage compatibly with load-handling forks mounted on the carriage. The slipsheet handler comprises a push-pull assembly and split platen, both of which receive their vertical support from the load-supporting surfaces of the forks. Attachment of the push-pull assembly to the lower hook-type bar of the carriage provides resistance against fore-and-aft movement of the slipsheet handler. To convert the truck rapidly to a fork-type truck capable of handling standard rigid pallets rather than slipsheets, the platen may be quickly removed leaving the push-pull assembly in place or, alternatively, the push-pull assembly and platen may be removed as an integral unit.