# US 4,400,128 A · Pallet unloading apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,400,128 A - Document ID: US4400128A - Status: Granted - Kind: A - Application number: 06/256,125 - Filed: 1981-04-21 - Granted: 1983-08-23 - Earliest claimed: 1981-04-21 - Assignees: Willamette Industries, Inc. - Inventors: Timothy H. Milligan - Web page: https://patentgrep.com/patent/US4400128A ## CPC - B65B 69/00: Unpacking of articles or materials, not otherwise provided for - B65G 1/00: Storing articles, individually or in orderly arrangement, in warehouses or magazines (conveyor combinations in warehouses, magazines or workshops B65G37/00; stacking of articles B65G57/00; removing articles from stacks B65G59/00; loading machines B65G65/02) - B65G 2201/0267: Pallets - Y10S 414/107: Recirculates emptied pallet or separator - B65B: MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING (bundling and pressing devices for cigars A24C1/44; devices for tensioning and securing binders adapted to be supported by the article or articles to be bound B25B25/00; applying closure members to bottles, jars or similar containers B67B1/00-B67B6/00; concurrent cleaning, filling and closing of bottles B67C7/00; emptying bottles, jars, cans, casks, barrels or similar containers B67C9/00) - B65G: TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS (packaging B65B; handling thin or filamentary materials, e.g. paper sheets or thread, B65H; cranes B66C; portable mobile or lifting or hauling appliances, e.g. hoists, B66D; devices for lifting or lowering goods for loading or unloading purposes, e.g. fork-lift trucks, B66F9/00; emptying bottles, jars, casks, barrels or similar containers, not otherwise provided for, B67C9/00; delivering or transferring liquids B67D; filling or discharging vessels for liquefied, solidified or compressed gases F17C; pipe-line systems for fluids F17D) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract An apparatus for unloading stacked sheet material from a supporting surface such as a pallet. A frame structure is provided including a station for positioning a loaded pallet. A ram reciprocates between an advanced and a retracted position at a height sufficient to pass over the pallet. Sweeping means is mounted on the ram for frictional sweeping engagement with the sheet material and pallet to remove cleanly all of the stack of sheet material. ## Claims ### Claim 1 An apparatus for unloading stacked sheet material from a support comprising: (a) a frame structure including a station for positioning the support having the stack of sheet material thereon; (b) forward and rearward support-engaging stops on the frame structure for limiting movement of the support in forward and rearward directions, (c) a ram reciprocatably mounted on the frame structure at a height sufficient to pass over the support and operable to move between an advanced forward position and a retracted rearward position; (d) sweeping means mounted on the ram and extending therebelow for frictional sweeping engagement with the sheet material and the support for pushing the support to its forward stop and then pushing the stack of sheet material from the support to the advanced forward position of the ram and for pulling the support back to its rearward stop; and (e) drive means mounted on the frame structure for reciprocating the ram. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the support comprises a pallet. ### Claim 3 (depends on 1) The apparatus of claim 1 further comprising a pair of tracks, one adjacent each side of the support, and a pair of reciprocatable carriages, one mounted on each track, the ram being mounted on and reciprocatable with the carriages. ### Claim 4 (depends on 3) The apparatus of claim 3 wherein the ram comprises an elongated stack-pushing member extending between the carriages, a rearwardly projecting extension attached at each end of the stack-pushing member, and pivot means for pivoting the ram on the carriages at a point rearwardly of the stack-pushing member, whereby the face of the ram is operable to move upwardly to accommodate supporting surfaces of varying height. ### Claim 5 (depends on 3) The apparatus of claim 3 further comprising an adjustment screw mounted on the ram and resting on one of the carriages to determine and to substantially maintain the height of the face of the ram. ### Claim 6 (depends on 3) The apparatus of claim 3 wherein the drive means comprises a drive screw extending along each of the tracks and engaging the carriages to drive them forwardly or rearwardly. ### Claim 7 An apparatus for unloading stacked sheet material from a support comprising: (a) a frame structure including a station for positioning the support having the stack of sheet material thereon; (b) a ram reciprocatably mounted on the frame structure at a height sufficient to pass over the support and operable to move between an advanced position and a retracted position; (e) a piece of flexible belting forming sweeping means attached to the face of the ram and extending therebelow for frictional sweeping engagement with the sheet material and the support; and (d) drive means mounted on the frame structure for reciprocating the ram. ### Claim 8 An apparatus for unloading stacked sheet material from a support comprising: (a) a frame structure including a station for positioning the support having the stack of sheet material thereon; (b) a ram reciprocatably mounted on the frame structure at a height sufficient to pass over the support and operable to move between an advanced position and a retracted position; (c) a bladder of rough material forming sweeping means mounted on the underside of the ram and extending therebelow for frictional sweeping engagement with the sheet material and the support; and (d) drive means mounted on the frame structure for reciprocating the ram.