Abstract: A method and apparatus for stacking first and second loaded pallets includes a pallet stacker that defines a stationary stacking location. A first loaded pallet is conveyed to the stationary stacking location. A pair of pallet lift carriages are vertically adjustable at the stationary stacking location to selectively engage the first loaded pallet and raise it to a temporary holding position. A second loaded pallet is conveyed into vertical registration with the first loaded pallet. The first loaded pallet is then vertically adjusted into stable stacked relation with the second loaded pallet, and the pallet lift carriages disengage the first loaded pallet. The first and second loaded pallets, in stable stacked relation to each other, thereafter are discharged from the stationary stacking location.

Abstract: A safety feature prevents a two wheeled electric paper lift from raising a paper tray on uneven ground that includes a tilt switch positioned in parallel with an upper limit switch that controls the height in a vertical direction of the paper tray. When a tilt angle of the paper lift is greater than 50 the tilt switch will prevent the paper tray from being raised and thereby prevent the load on the paper tray from shifting or tipping over and causing injury to an operator.

Abstract: A pallet positioner includes a support frame that consists of a main upright structure with a pair of spaced, parallel outriggers extending horizontally at ground level. The distal ends of the outriggers are connected by a low-profile ramp. The upright structure includes a pair of vertical guide masts rigidly mounted on a horizontal base bracing the proximal ends of the outriggers. A pneumatically and hydraulically controlled, or electrically and hydraulically controlled, cantilevered carrier with a rotatable platform is mounted for vertical motion along the vertical guide masts. When the carrier travels downward, the carrier stops automatically at a level above the outriggers and must be manually restarted. A braking system under the platform prevents rotation thereof at ground level.

Abstract: A preferred embodiment of a lift and carrier assembly for a personal-transportation vehicle includes a deck frame, a platform, and a trolley assembly mounted on the deck frame. The trolley assembly includes a drive nut, a motor for rotating the drive nut, and a drive screw threadably coupled to the drive nut so that rotation of the drive nut causes the platform and the drive motor to translate linearly in relation to the deck frame. The lift and carrier assembly also includes an arm assembly mounted on the trolley system and comprising a first and a second arm member, and an actuator pivotally coupled to the first and second arm members for moving the first and second arm members so that first and second arm members move the platform between an upper and a lower position in relation to the deck frame.

Abstract: In an elevating mechanism 14 where an elevating mechanism 17 carried so as to rise and fall along a fixed surface 16 is moved up and down through a suspension member 18, a braking mechanism 18 is born by the elevating mechanism 17 so as to pivot vertically. A tensile spring 32 is provided on the braking mechanism 31, for pivotally urging it to the direction close to the fixed surface 16, while the suspension member 18 is connected to the braking mechanism 31, for pulling the braking mechanism 31 in the direction apart from the fixed surface 16 due to the weight of the elevating mechanism 17, in opposition to the tensile spring 32. When the suspension member 18 is cut off, then the braking mechanism 31 comes into contact with and digs into the fixed surface 16 by action of the tensile spring 32, so that the elevating mechanism 17 can be stopped from falling.

Abstract: In an elevating mechanism 14 where an elevating mechanism 17 carried so as to rise and fall along a fixed surface 16 is moved up and down through a suspension member 18, a braking mechanism 18 is born by the elevating mechanism 17 so as to pivot vertically. A tensile spring 32 is provided on the braking mechanism 31, for pivotally urging it to the direction close to the fixed surface 16, while the suspension member 18 is connected to the braking mechanism 31, for pulling the braking mechanism 31 in the direction apart from the fixed surface 16 due to the weight of the elevating mechanism 17, in opposition to the tensile spring 32. When the suspension member 18 is cut off, then the braking mechanism 31 comes into contact with and digs into the fixed surface 16 by action of the tensile spring 32, so that the elevating mechanism 17 can be stopped from falling.

Abstract: In an elevating mechanism 14 where an elevating mechanism 17 carried so as to rise and fall along a fixed surface 16 is moved up and down through a suspension member 18, a braking mechanism 18 is born by the elevating mechanism 17 so as to pivot vertically. A tensile spring 32 is provided on the braking mechanism 31, for pivotally urging it to the direction close to the fixed surface 16, while the suspension member 18 is connected to the braking mechanism 31, for pulling the braking mechanism 31 in the direction apart from the fixed surface 16 due to the weight of the elevating mechanism 17, in opposition to the tensile spring 32. When the suspension member 18 is cut off, then the braking mechanism 31 comes into contact with and digs into the fixed surface 16 by action of the tensile spring 32, so that the elevating mechanism 17 can be stopped from falling.

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 wheelchair carriage in which an upright support post detachably couples to a towing frame of a vehicle. A tubular housing slidably receives an end of the post and is biased against the post. An enclosure for holding a wheelchair includes a base member mounted to the housing, a platform mounted to a lower end of the base member, and a rack attached to an upper end of the base member. A lever has a lever arm pivotally attached to the upright support post, and a lever handle joined to the lever arm at a fulcrum pivotally attached to the housing. The lever handle, being moved in a first direction, bears against the fulcrum to move the enclosure to the first position for wheeling a wheelchair onto the platform. The lever handle, being moved in a second direction opposite to the first direction, raises the enclosure to the second position to a height sufficient to prevent the carriage from impeding the clearance of the vehicle for traveling.

Abstract: A guard fence is mounted on a transfer arm used to transport a boat carrying semiconductor wafers. The fence limits tipping movement of the boat and includes a plurality of sensors to sense tipping movement of both the top and bottom of the boat, in opposite tipping directions. A guard cover includes sensors that sense when the boat is tipped off-axis before the boat is moved into a process chamber by a boat elevator. Each of the sensors delivers signals to a controller which controls the operation of the transfer and elevator and interrupts operation thereof when the boat has tipped off-axis.

Abstract: An autohandler for supplying a lot of feed trays carrying samples and for removing a lot of return trays loaded with tested samples. A loading mechanism has a feed tray elevator containing samples to be tested. An unloading mechanism has a return tray elevator for receiving return trays containing tested samples. An empty tray storage unit stores empty trays. A tray transfer hand transfers the trays. A sensor detects the feed tray elevator position. The sensor actuates an alarm when the feed tray elevator is almost empty.

Abstract: A mobile vehicle having a substantially hexagonally-shaped frame member that is movable between a collapsed position to enable the vehicle to enter a vessel opening or an area having constrained access points and a more stable expanded position. Drive apparatuses are attached to the frame member for driving the vehicle on a surface. The vehicle is also equipped with a tether line that is used to supply control power to the vehicle drives and to deploy and retrieve the vehicle. Various collapsible tool members are operably attached to the vehicle for performing various tasks within an enclosed environment.

Abstract: A hydraulic lift valve system for fork lift trucks comprising a three way valve including a spool in a bore having a first neutral position, a second lift position and a third lower position. In the second lift position, the spool functions to apply fluid from a source to a cylinder for lifting the fork of the truck only after the pressure exceeds the load pressure and a predetermined value as established by a first poppet valve. Upon shifting to the third position the spool functions to permit exhaust of the fluid in the cylinder and therefore lowering the fork only after a predetermined pressure is established in a pilot valve which permits the first poppet valve to open, thereby insuring that the fork of the lift truck is not lowered unless there is a predetermined load on the fork. By this arrangement, the problem of uncontrolled descent of the fork upon engagement of the fork with an object is obviated.

Abstract: Movable sensing arrangements are prone to damage, unable to position a load engaging device relative to a load for stacking purposes, and unable to controllably position the sensing arrangement. A movable sensing apparatus having a housing and first and second signaling devices mounted in the housing is provided. A guide rail assembly elevationally movably mounts the housing on a carriage assembly and an actuator controllably elevationally moves the housing along the guide rail assembly. A coupling connects the actuator to the housing and releases the housing from connection with the actuator in response to a force of a preselected magnitude being applied to the housing. Thus, the problems related to damage, stacking, and positioning are reduced. The movable sensing apparatus is particularly suited for use on an automatic guided unmanned vehicle having a lift mast assembly.

Abstract: An apparatus for loading a wheelchair or similar object into a vehicle. When in a stored position, the apparatus and wheelchair are fully contained within said vehicle. A first embodiment illustrates use of the apparatus in a rear compartment of a station wagon, van or similar vehicle in which a pair of motor-driven drive links and a pair of drag links are utilized to lift and rotate a chair rack and wheelchair mounted thereon into said vehicle rear compartment. The drive and drag links connect the rack to a carriage which may then be rolled from a rearwardmost to a forwardmost position for final storage of the apparatus and chair in the vehicle. Latching means is provided to latch the carriage in either its forwardmost or rearwardmost positions. A remote control switch and limit switches are used to control power to the electric motor. A second embodiment of the apparatus is designed for use in the trunk of a typical passenger automobile.

Abstract: Apparatus for stacking articles, particularly pallets on which articles having a substantially flat surface, preferably large sacks, have been deposited, the apparatus includes spaced apart parallel tines, which constitute lifting arms and are adapted to extend under the pallets or into openings thereof and are mounted on a slide, which is movable in vertical tracks and adapted to be lifted and lowered by a drive device. The vertical tracks are connected to a stationary base frame. The tines are extensible and retractable and guided in tracks of the slide. A conveyor for the articles to be stacked is disposed below the tines when they have been extended.

Abstract: Disclosed is a system for automatically loading a transport vehicle with unit loads by automatically moving the unit loads from a predetermined loading position to prescribed positions in the transport vehicle. The present invention uses a loading vehicle which receives loads from a staging device which positions the unit loads in the predetermined loading position. A unit load transfer device transfers the unit loads from the staging device to the loading vehicle. The loading vehicle uses on-board sensors in combination with placement information provided by a staging processor to perform translational and operational movements which are processed by an on-board loading vehicle processor. Unit loads can be deposited throughout the transport vehicle by maintaining a guidance path which is internally generated within the transport vehicle and can be either internally or externally generated outside the transport vehicle.

Abstract: Controlling arrangements of the type used for aligning a load engaging assembly with a load to be lifted tend to be bulky, costly, unable to accurately position the load engaging assembly with the load to be lifted, and unable to accommodate different types of load supporting structures. A controlling arrangement having a signal assembly having first and second spaced apart portions is provided. The first portion is adapted to deliver a first signal and receive a reflection of the first signal and the second portion is adapted to deliver a second signal and to receive a reflection of the first signal. A single sensing device is adapted to receive the reflected signals and a selecting device controls the operation of the first and second signal assembly portions. Therefore, the problems of bulk, cost, inaccuracy and flexibility are eliminated. The controlling arrangement is particularly suited for use on a material handling vehicle.

Abstract: In a material handling vehicle having an operator platform, a sideshift carriage mounted for lateral movement relative to the platform, a traverse carriage mounted for lateral movement relative to the sideshift carriage and forks mounted to the traverse carriage, an improved sideshift control system monitors the position of the sideshift carriage to define home positions for the sideshift carriage relative to the platform. Two home positions are defined, one for the forks facing to each side of the vehicle. The home positions offset the sideshift carriage to one or the other side of the platform to substantially center the load on the vehicle such that a portion of the base of the forks extends a set distance beyond one side of the platform, and the load supported on the forks extends approximately an equal distance beyond the opposite side of the platform.

Abstract: A safety locking mechanism for locking a hoist, such as a power operated tailgate, with repect to its supporting structure comprises: a pair of latch arms which are connected to one another by a flexible cable. A pair of power transmission chains connect the hoist to a power source. A pair of tension sensing lever arms are pivotally mounted and arranged to detect the presence or absence of a normal loading tension in the power transmission chains. The flexible cable also engages each of the tension sensing levers and is held by them in a position in which it retains the latch arms in a released position when a normal loading tension is detected in the power transmission chains. The latch arms will both move to a latching position locking the hoist when the absence of a normal loading tension is detected in the power transmission chains.

Abstract: An improved system for monitoring lift chains included within mast assemblies in material handling vehicles disables downward movement of the forks upon detection of a first level of slackness in a lift chain. Since upward movement of the forks is not disabled, the forks may be raised to clear any obstruction causing the chain slackness. A lift chain may also be monitored to detect a broken chain in which case all vertical movement of the forks is disabled. In a material handling vehicle wherein the operator is elevated along a first mast and the forks are elevated along a second mast connected to an operator's platform, dual lift chains in the first mast are individually monitored for both slackness and breakage while dual lift chains in the second mast are monitored in common primarily to detect slackness. Lateral and rotational movement of the forks is also disabled for detection of a slack or broken first mast lift chain, but not for detection of a slack or broken second mast lift chain.

Abstract: A lift system for a transit vehicle includes a stationary main frame secured within a door recess of the vehicle and a side frame that is movable relative to the main frame. An articulated platform including steps pivotally secured to the side frame and scissor linkage pivotally and slideably connected to the main frame is also included. The lift system also includes a reaction switch coupled to the main frame to sense torque imparted to the main frame upon engagement of the platform with an obstacle such as a curb or the ground. If sufficient torque is created due to contact of the platform with an obstruction, the reaction switch is actuated to terminate further downward movement of the platform thereby preventing destruction of the system.

Abstract: An electrically controlled hydraulic lift, such as wheelchair lifts for vehicles, wherein the hydraulic reciprocating motor for operating the platform of the lift is mounted in a vertical slot so that any obstruction in the downward movement of the platform of the lift will cause the reciprocating motor to rise in the slot and operate a microswitch to automatically shut off the continued supply of fluid to the reciprocating motor. This arrangement not only prevents the crushing of obstacles that get in the downward path of the platform, but also limits the downward movement of the platform when it contacts the solid ground or floor level from which an object is to be lifted, such as an invalid in a wheelchair. If desired, the upward movement of the reciprocating hydraulic motor may be restricted by resilient means for maintaining it in the lower part of its mounting slot.

Abstract: The disclosure is directed to a grab bucket suspended from the cable of a hoisting means. The hosting means includes a first reversible motor drive means to raise and lower the grab bucket and a second motor drive means is associated with the grab bucket for opening and closing the bucket. Pursuant to the invention, a slack line limit switch is arranged and configured to detect a slackening condition in the cable as when the bucket reaches a pile of material. Upon said slackening condition, the limit switch operates to stop the first reversible motor drive means and to start the second reversible motor drive means to commence the closing of the bucket.

Abstract: The invention relates generally to steerable vehicles, particularly fork lift trucks, which include one or more travel drive motors adapted to be controlled in a predetermined manner, and a steerable swivelled wheel assembly. To increase the safety of such vehicle in operation, an electrically controlled drive control system is provided which is simple and free from elements that are susceptible to wear. For this purpose, two speed sensors are provided on opposite sides of the vehicle and cooperate with respective coaxial road wheels and are connected by a comparator to a switching system for controlling the travel drive, e.g., to a travel control signal generator. Elements for applying at least one additional speed-influencing input signal are associated with the comparator.

Abstract: A fork lift truck is equipped with an attachment or fixture for handling a plate glass load. The truck is also equipped with a control system which includes sensing switch means for controlling automatically the operation of the truck to insure safe pick-up of the plate glass load. The control system also includes release switch means for preventing the truck from backing up, following deposit of a plate glass item at a storage area, until the plate glass load fixture has cleared the plate glass item.

Abstract: A bucket conveyor is provided with a frame having upwardly inclined spaced parallel guide rails which support the bucket for up and down movement along the inclined guide rails, a chain-and-sprocket bucket support and drive mechanism is disposed along each side of the conveyor frame with the bucket being secured to the chains for movement therewith so that when the bucket is brought to the upper most end portion it will rotate around the sprocket at that location and thus dump the contents of the bucket. An alternative embodiment utilizes a bucket with a hinged bottom which falls away as the bucket reaches the top of the conveyor.

Abstract: A force-moment compensating apparatus, particularly adapted for use with load handling apparatus, including stabilizing means, sensing means for sensing a change in value of a force-moment acting on the apparatus, and actuator means responsive to the sensing means for restoring the force-moments acting on the apparatus to a stable condition.