WORKPIECE LOADER AND UNLOADER

• US 3,766,617 A
• Filed: 10/18/1971
• Issued: 10/23/1973
• Est. Priority Date: 10/18/1971
• Status: Expired due to Term

• Current Assignee: Motch Corporation (BKH Holdings, Inc.)
• Original Assignee: John A. Adamcik, Peter E. Forster
• Inventors: Forster, Peter E., Adamcik, John A.
• Primary Examiner(s): Weidenfeld, Gil
• Application Number:
  US05/190,173
• Time in Patent Office: 736 Days
• Field of Search: 29/563,564,33P,568 408/67,69,70,44,108,109 198/19 214/1BB,1BC,1BH 90/11R
• US Class Current: 29/33.00P
• CPC Class Codes: B21D 43/10 by grippers B21D43/055, B21D43/057, B21D43/145 take precedence
• CPC Class Codes: Y10T 29/5124 with means to feed work intermittently from one tool station to another
• CPC Class Codes: Y10T 29/5196 Multiple station with conveyor
• CPC Class Codes: Y10T 408/52 with work advancing or guiding means

Abstract

Workpiece loaders and unloaders for use as with a multi-station machining line including a series of machine tools and a workpiece conveyor therealong operative to transport workpieces for loading into the respective machine tools and to receive workpieces unloaded from the respective machine tools for transport to successive machine tools, each workpiece loader and unloader being equipped with a pair of workpiece clamps and being operative upon each 180* indexing of the clamp support structure thereof to transfer a workpiece from the conveyor to the associated machine tool and to transfer a workpiece from the associated machine tool to the conveyor. When the workpieces have been transferred as aforesaid the loader and unloader clamps are opened for chucking of the workpieces in the respective machine tools and for transport of the workpieces on the conveyor to the succeeding work stations. A characterizing feature of the present workpiece loader and unloader is its simplicity and compactness to minimize the center-to-center distance between the diametrically opposed workpiece clamps thus to minimize inertia forces. The loader and unloader herein is further characterized in that the clamps thereof are hydraulically actuated for rapid opening and closing movements with provision for cushioning such movements to reduce shock load on the equipment.

Claims

1. A workpiece loader and unloader disposed between a loadunload station and a work station, said load-unload station including conveyor means to convey workpieces thereto and therefrom and said work station including a machine tool having chuck means to hold workpieces for machining operations thereon;

said loader and unloader comprising a pair of clamp means and actuating means therefor operative selectively to grasp or release workpieces at said stations;

indexable clamp support means operative when said clamp means are closed to transfer a workpiece from said load-unload station to said work station and to transfer a workpiece from said work station to said loadunload station;

said clamp means, when operated to release said workpieces, releasing a workpiece at the load-unload station for replacement by a succeeding workpiece and releasing a workpiece at said work station for holding by said chuck means and for machining by said machine tool;

each of said clamp means comprising a pair of clamp arms movable toward and away from each other about parallel pivots on said support means, and intermeshing gears on said clamp arms coaxial with said pivots;

said clamp actuating means comprising a pair of side by side parallel fluid pressure actuated pistons in said support means between the parallel pivots of said pairs of clamp arms;

each piston having a gear rack engaging the gear on one clamp arm of the respective pairs of clamp arms to provide synchronizeD movements of said clamp arms responsive to movement of said pistons.

2. The workpiece loader and unloader of claim 1 wherein said support means is disposed above said conveyor means and said chuck means and is supported for indexing movement about a vertical axis midway between said pair of clamp means and said pistons.

3. The workpiece loader and unloader of claim 2 wherein vertical actuating means is operatively connected to said support means to raise and lower the same respectively to lift the workpiece from said chuck means prior to indexing and to lower the workpiece into said chuck means after indexing.

4. The workpiece loader and unloader of claim 1 wherein one clamp arm of each pair of clamp arms longitudinally adjustably carries a workpiece engaging jaw;

and wherein the other clamp arm of each pair of clamp arms laterally adjustably carries a workpiece engaging jaw.

5. The workpiece loader and unloader of claim 1 wherein said conveyor means includes stop means movable into and out of the path of movement of a released workpiece and a succeeding workpiece on said conveyor means whereby, upon movement of said stop means out of the path of said workpieces, said released workpiece and succeeding workpiece are respectively conveyed from said load-unload station and conveyed to said load-unload station, said stop means, when subsequently moved into such path, positioning said succeeding workpiece at said load-unload station and positioning another succeeding workpiece in advance of said load-unload station.

6. The workpiece loader and unloader of claim 3 wherein said clamp means, when operated to release said workpieces, clears the latter for replacement and machining without raising said support means.

7. A workpiece loader and unloader disposed above and midway between a load-unload station and a work station, said load-unload station including conveyor means to convey workpieces thereto and therefrom and said work station including a machine tool having chuck means to hold workpieces for machining operations thereon;

said loader and unloader comprising a vertical guide member;

clamp support means having a shaft portion rotatable in said vertical guide member about a vertical axis midway between said stations and having a head portion with two pairs of vertical pivots on opposite sides of the axis of rotation of said shaft portion;

two pairs of horizontally extending clamp arms pivotally mounted at one end to the respective pairs of pivots for movement of the other ends thereof toward and away from each other to hold and release workpieces therebetween;

each pair of clamp arms having intermeshing gears coaxial with said parallel pivots;

a pair of side by side horizontal fluid pressure actuated pistons in said head portion between said pairs of pivots having gear racks meshing with one of the gears associated with each pair of clamp arms to provide synchronized movements of said clamp arms responsive to movement of said pistons in opposite directions;

indexing means on said vertical guide member engaged with said shaft portion operative when said clamp arms are engaged with workpieces at said stations to transfer a workpiece from said load-unload station to said work station and to transfer a workpiece from said work station to said load-unload station;

said clamp arms when operated to release said workpieces, releasing a workpiece at the load-unload station for replacement by a succeeding workpiece and releasing a workpiece at said work station for holding by said chuck means and for machining by said machine tool.

8. The workpiece loader and unloader of claim 7 wherein said conveyor means includes stop means movable into and out of the path of movement of a released workpiece and a succeeding workpiece on said conveyor means whereby, upon movement of said stop means out of the path of said workpieces, said released workpiece and succeeding workpiece are respectively conveyed away from said load-unload station and conveyed to said load-unload staTion, said stop means, when subsequently moved into such path, positioning said succeeding workpiece at said load-unload station and positioning another succeeding workpiece in advance of said load-unload station.

9. The workpiece loader and unloader of claim 7 wherein said vertical guide member has reciprocating means operatively connected to said shaft portion to raise and lower said head portion and said pairs of clamp arms respectively to lift the workpiece from said chuck means prior to indexing and to lower the workpiece into said chuck means after indexing.

10. The workpiece loader and unloader of claim 9 wherein said pairs of clamp arms, when operated to release said workpieces, clear the latter for replacement and machining without raising said head portion and pairs of clamp arms.