Accumulating lift and carry conveyor

Abstract

A conveyor for transferring articles from station to station in an operation which includes lifting the article, transporting it to the new station, and lowering the article into position. Means are provided to sense the presence or absence of an article at every station and to provide for advance of articles from every station in rear of the most advanced empty station.

I claim: 
     
       1. An accumulating conveyor comprising an elongated frame having a multiplicity of equally spaced work support stations, a slide movable longitudinally of said frame, means for reciprocating said slide in back and forth strokes having an amplitude exceeding the spacing between stations, means for elevating and lowering said slide, a plurality of individually movable carriers on said slide, abutment means acting between each pair of adjacent carriers operable on movement of any one of said carriers from an idle to a feed position to move all carriers to the rear of said one carrier to feed position, a control arm carried by said frame at each station having a cam normally in operative position but movable by a workpiece at such station to inoperative position, an element connected to each carrier engageable with the associated control arm cam when the control arm is in operative position to shift the associated carrier to feed position beneath its associated station during initial movement of said slide in feed direction from a starting position to an intermediate position in which the carriers in feed position are directly beneath workpieces at the associated stations, means for actuating said slide elevating and lowering means to elevate said slide and carriers at said intermediate positions to cause said carriers to lift the workpieces at the associated stations, means for thereafter actuating said slide-reciprocating means to continue advance of said slide to advance the workpieces lifted by said carriers to the next station, means for thereafter actuating said slide elevating and lowering means to lower said slide to deposit workpieces at said next station, means for thereafter actuating said slide-reciprocating means to return said slide to initial position, and means engageable with said carriers to return said carriers to idle position during return movement of said slide. 
     
     
       2. An accumulating conveyor as defined in claim 1 in which said carriers each comprises an elongated member having a length equal to the spacing between stations, and which includes parallel links pivotally supporting said members on said slide, one of said links having an arm movable to upwardly extending feed position and having a work support configuration at its upper end. 
     
     
       3. An accumulating conveyor as defined in claim 2 in which said links are movable through an arc of approximately 90° through an upwardly extending vertical position upon forward movement of said slide-following engagement between the elements associated therewith and said cams. 
     
     
       4. An accumulating conveyor as defined in claim 3 in which said means for returning said carriers to idle position comprise movable cams, and abutment means holding said movable cams in operative positions during return movement of said slide. 
     
     
       5. An accumulating conveyor as defined in claim 4, said movable cams comprising pivoted arms movable by said carriers to inoperative position on forward movement of said slide. 
     
     
       6. An accumulating conveyor as defined in claim 4 in which said carriers move overcenter during movement between idle and feed position, and means to control movement of one portion thereof in timed relation to movement of said slide. 
     
     
       7. An accumulating conveyor as defined in claim 1 comprising abutment means acting between said slide and said frame to terminate advance of said slide with said carriers directly beneath associated stations, said last mentioned abutment means being shaped to disengage upon elevation of said slide. 
     
     
       8. An accumulating conveyor as defined in claim 7 in which said elements engageable with said control arm cams are movable upwardly by upward movement of said slide to positions above said cams to provide for further forward movement of said slide. .[.9. A lift and carry conveyor comprising an elongated stationary frame providing a series of equally spaced article-supporting stations, a slide movable longitudinally of said frame, mechanical article-sensing devices on said frame at each station, individually movable article carriers on said slide movable between idle and feed positions, one-way positive acting mechanical means acting between each pair of adjacent carriers operable when any one carrier is shifted to feed position to move all carriers to the rear of said one carrier to feed position an element on each carrier engageable with the article-sensing device at the empty station to which said carrier can deliver an article and operable through said positive acting means to move said carrier to feed position and to move all carriers to the rear of the said carrier moved to feed position..]. .[.10. A conveyor as defined in claim 9, comprising means for sequentially elevating said slide and carriers while said carriers remain at associated stations to elevate articles from support stations, advancing said slide to move articles forwardly to the next succeeding station, lowering said slide and carriers to deposit articles on the next succeeding station, and returning said slide and carriers to initial position..]. .[.11. Mechanism as defined in claim 10, which comprises rigid abutment means operable on return movement of said slide engageable with said carriers to shift said carriers to idle position..]. .[.12. Mechanism as defined in claim 11, said abutment means comprising guide means to control return movement of said carriers in 
     
     
        timed relation to movement of said slide..]. 13. An accumulating conveyor comprising an elongated frame having a multiplicity of equally spaced support stations, a slide movable longitudinally .Iadd.and vertically .Iaddend.of said frame .Iadd.between an initial lowered return position and an elevated advanced position.Iaddend., means for reciprocating said slide in forward feeding and reverse strokes having an amplitude at least as great as the spacing between said stations, means for elevating and lowering said slide, a plurality of carriers on said slide, each of said carriers being independently movable on said slide between idle and feed positions, abutment means acting between each pair of adjacent carriers operable on movement of any one of said carriers from an idle to a feed position to move all carriers to the rear of said one carrier .Iadd.moved .Iaddend.to feed position .Iadd.but not to so move carriers forwardly of said one carrier.Iaddend., a control arm carried by said frame at each station having a cam normally in operative position but movable by a workpiece at such station to inoperative position, an element connected to each carrier engageable with the associated control arm cam when the control arm is in operative position to shift the associated carrier to feed position beneath its associated station during and as a consequence of movement of said slide .Iadd.from said initial position.Iaddend., means for actuating said slide-elevating and lowering means to elevate said slide and carriers to cause the carriers in feed position to lift the workpieces at the associated stations, means for thereafter actuating said slide-reciprocating means to advance the slide to advance the workpieces lifted by said carriers to the next station, means for thereafter actuating said slide-elevating and lowering means to lower said slide to deposit workpieces at said next station and means for thereafter actuating said slide-reciprocating means to return said slide to .Iadd.said .Iaddend.initial position, said carriers having means connected thereto effective to return all carriers in feed position to idle position during 
     
     
        reverse reciprocation of said slide. .Iadd.14.  A lift and carry conveyor comprising: an elongated stationary frame providing a series of equally spaced article supporting stations; a slide movable longitudinally of said frame between an initial return position and an advanced position; mechanical article sensing devices on said frame at each station; individually movable article carriers on said slide movable between idle and feed positions; actuating means including means bringing said carriers moved to feed position into contact with said articles and elevating articles from said supporting stations; said actuating means also including means moving said slide, carriers, and elevated articles forwardly to said advanced position to move articles supported on said carriers to the next succeeding stations, said actuating means further including means lowering said carriers to deposit said articles on the next succeeding stations, and said actuating means additionally including means moving said slide and carriers rearwardly to said initial position; one way positive acting mechanical means between each pair of adjacent carriers operable when any one carrier is shifted to feed position to move all carriers to the rear of said one carrier to feed position while not so moving carriers forward of said one carrier; an element on each carrier engageable by movement of said slide from said initial position with the article sensing device at the empty station to which said carrier can deliver an article and operable to move said carrier to feed position; said one-way positive acting mechanical means acting to move to feed position all carriers to the rear of the said carrier but not to so move carriers forward of said carrier; means for moving said carriers to idle position during motion of said slide from said advanced position. .Iaddend.