720,452. Endless conveyers. ARNOLD, J. C. (Pneumatic Scale Corporation Ltd.). Dec. 4, 1952, No. 30840/52. Class 78 (1). [Also in Group XVI] Apparatus for stacking and conveying flat packages, e.g. bags of the envelope or pillow type, comprises an endless conveyer having a plurality of vertically dispersed hollow bag-receiving pockets open at top and bottom, a gripper device for transferring successive bags from a source of supply to a position immediately beneath a pocket, and an elevator for lifting successive bags into the open bottom of a pocket to form a stack adapted to be withdrawn as a group through the open top of the pocket. The apparatus (Fig. 2) comprises an endless conveyer chain 12 having a plurality of pockets 14 into which the bags are inserted by an elevator 50 in co-operation with a gripper device 52, 54 which takes the bags from tagging apparatus 20 as described in Specification 617,986, which include grippers 24. The chain 12 is rotated by a sprocket wheel fast on a shaft 40, the pockets 14 being vertically mounted on the shaft and supported by guide rails 51, 53. The gripper device for taking the bags from the gripper 24 comprises jaws 52, 54 pivotally supported on a stud 56 (Fig. 4) carried by a reciprocal slide 58. The jaws 52, 54 are spring-biased together and arranged to be opened by a cam-piece 62, carried by and depending from a second upper reciprocal slide 64, co-operating with rollers 66 on the jaws. The slide 58 is reciprocated by cam-operated linkages 72, 74, 77, 78, 80, 82, 86, the bell-crank arm 86 being provided with a roller 88 cooperating with a cam 90 fast on a cam-shaft 48. A similar cam-operated linkage 92, 96, 98, 102, 104, and cam 108 is provided for reciprocating the slide 64. For taking the bags from the grippers 24 on the right-hand side (as shown) of the tagging apparatus 20 the cam arms 86, 104 are connected by links as 110 to arms 114, 116 of three-armed levers pivotally mounted at 118, the second arms of which are connected by links 124, 126 to respective slide-operating linkages. The third arms 128, 130 are connected by springs 132 for retaining the rollers 88, 106 in co-operative engagement with the cams 90, 108. The upper slide 64 also carries a cam-piece 134 for co-operation with abutments 36 of the grippers 24 so as to open them. In operation the slides 58, 64 are extended forwardly so that the gripper jaws 52, 54 group and withdraw a bag from a gripper 24 which rotates in timed relation on a chain 22. The bag is then conveyed by the jaws 52, 54 on retraction of the slide to a position directly below a pocket 14, the jaws then being opened by engagement of an extension 136 on the jaw 54 with a stopmember 138 adjustably fixed on the slide frame bracket 68. The elevator 50 is mounted on a vertically reciprocal shaft 140 supported in a bearing 142 and adapted to reciprocate in timed relation to the operation of the jaws 52, 54, through linkages operated by a cam 158 on the shaft 48, and roller 156 on one arm 154 of a two-armed lever pivoted at 118, the other arm 152 being connected through the linkages to the shaft 140. Similar linkages are provided on the other side of the chain 22 for elevating a second shaft 140 dealing with bags from the right-hand gripper 24. Each pocket 14 is provided with a rear wall 162, secured to a link 12 of the conveyer chain, and side walls 164. The front is provided with guides 166 leaving a clear centre position to enable an operator to withdraw the bags as a group. The bottom of each pocket is provided with spring-biased bag retaining members 168, the elevator 50 being H-shaped in plan so as to avoid contact therewith. To ensure delivery of a predetermined number of bags into each pocket an indexing mechanism 46 is provided operated by a crank 180 fast on the shaft 48 and connected by a link 182 to a pawl arm 184, carrying a pawl 190 and engaging a wheel 194 mounted on a shaft 186 which drives through bevel-gearing the conveyer driving shaft 40. Each cycle of the crank 180 is adapted to move the pockets 14 one station of operation. Movement of the conveyer is restrained, however, until the predetermined number of bags have been delivered into each pocket 14 by a roller 202 on an arm 200 which engages the tail 204 of the pawl 190 so as to render it incapable of engaging a slot 192 in the wheel 194. Retaining pawls 234, 236 are provided for preventing rotation of the wheel 194 when the pawl 190 is inoperative, a second roller 240 on the arm 200 releasing pawl 236 when an indexing movement is to be made. The arm 200 is operated through linkage 206, 208, 210, 214, roller 216 and co-operating cam 218 fast on a shaft 220 rotated from the camshaft 48 by gearing 224, 226, 230, 232, the ratio of which determines the number of bags which will be deposited in any one pocket before the conveyer is moved.