Patent GB-640379-A (GB)
Title: Improvements in or relating to automatic bag feeding machines
IPC: B65B43/18
Filed: 1947-08-01
Abstract: 640,379. Opening and filling bags. CONSOLIDATED PACKAGING MACHINERY CORPORATION. Aug. 1, 1947, No. 20963. Convention date, July 25, 1940. [Class 94(i)] A machine for supplying bags individually to opening devices of a filling machine, has a main supporting frame, a bag retaining magazine X (Fig. 6), bag transfer devices including a primary cradle E vertically movable on the frame and a secondary cradle 133 horizontally movable on the cradle E, bag feeding means operative between the magazine D and the transfer devices, means for moving the transfer devices horizontally in order to place the bag held thereby, into registry with the opening devices of the filling machine, and means to raise the transfer devices to apply the bag to the filling machine. The magazine X and mechanism comprising the bag feeding means. These are carried by spaced, parallel, vertically-disposed plates 32 each extending upwardly at 33 and horizontally at 34. The plates 32 are rigid with respective pillars 6 which are carried by a base plate 5. The magazine X comprises a stack 50 of bags supported on a series of rollers 52 each pivotally mounted at each end in side plates 51 carried respectively by the plates 33. The front end of the stack 50 is supported by an abutment plate 65 and by two laterally disposed clips 63 each of which supports the bottom bag of the stack at respective sides. Each clip 63 is inwardly urged by a respective compression spring (Fig. 4, not shown) and the stack is supported laterally by side plates (Fig. 3, not shown) which are adjustable to accommodate different bagwidths. The lowest bag is drawn from the stack 50 by means of a selector assembly 58 comprising a pair of suction cups 61 each carried by a hollow piston rod 60. The piston of the rod 60 works in a respective cylinder 59 which is connected via a pipe 194 and a valve device (Figs. 14 and 17) with a source of vacuum. The rod 60 is inwardly urged against the action of the vacuum by a spring within the cylinder, the arrangement being such that when vacuum is applied to each cylinder 59 by the valve 182 the rods 60 are projected until the cups 61 engage the bag. This closes the outlet of the rods 60 and causes pressure equalization in the cylinders 59 and the rods 60 return under the influence of the spring, drawing the bag into the position shown in Fig. 6. More selector assemblies 58 may be employed. In a modified construction (Fig. 38) the selector assembly is replaced by a series of suction cups 230 carried by a tube 229 suspended at each end by links 228 from the plates 51. A roller 232 carried by one end of the tube 229 is engaged by an arm 236 of a bell-crank the other arm of which carries a follower associated with a cam 239 on a main cam shaft 29 coupled by a chain-drive 23 with a main motor 8 (Fig. 2). When the bag is drawn by the suction cups 61 into the position of Fig. 6 the leading edge of the bag is engaged by gripping jaws 70, 71. The jaw 70 is rigid with the arm 69 of a bell-crank pivotally mounted on a shaft 67 carried at each end by the plates 34. The other arm 68 of the bellcrank carries a follower 78 associated with a cam 79 carried by a cam shaft 29. The gripper 71 is pivotally mounted on the end of the bell-crank arm 69 and is pivotally connected at its end with a rod 72 which is slidable in a block 73, pivotally secured to a plate 74 itself pivotally mounted on the shaft 67. The plate 74 carries a follower 80 associated with a cam 81 and is connected by a spring 82 with the axis of the follower 78, which tends to urge the followers 78, 80 in engagement with their respective cams 79, 81. A spring 75 acting between the block 73 and a collar on the rod 72, tends to turn the gripper in an anticlockwise gripping direction, but this action is limited by stop nuts 77 on the rod 72. Just prior to the position shown in Fig. 6, the lowest portion of the cam 79 is presented to the follower 78 which is held out of contact with the cam owing to the engagement of the high portion of the cam 81 with the follower 80. Rotation of the plate 74 under action of the cam 81 is transmitted to the bell-crank 68, 69 by the spring 82 and results in movement of the gripper as a whole towards the gripping position. When the follower 78 finally engages the cam 79, further rotation of the plate 74 acts via the spring 75 to bring the jaw 71 into gripping position. The follower 78 then rides the high part of the cam 79 so as to swing the arm 69 and gripped bag, rearwardly. When the block 73 re-engages the stop 77 during this movement; the gripper 71 is forced clockwise and 'releases the bag, the downward movement of which, is then restrained by a stop in the form of a U-shaped member 83. The central portion of the stop 83 is clamped at 84 to a shaft 85 which derives an oscillatory movement by linkage (Fig. 15, not shown) from a cam on the shaft 29, thus raising and lowering the stop arms in timed relation to the remainder of the mechanism. The bag is then positioned between two pairs of feed rolls 92, 93. The rolls 92 are knurled and are continuously rotated by their mounting on a shaft 42 which is driven by a pulley and belt connection 38 with a secondary driving motor (not shown) carried by a bracket on the plates 34. Each roll 93 is freely rotatable and is carried by a respective assembly (Fig. 12) which includes a stub-shaft 102 mounted in the arms of a yoke 101 which itself is freely journalled on a shaft 88 common to both assemblies. An arm 95 keyed to the shaft 88 lies adjacent the yoke 101 and has a slot 96 through which the shaft 102 passes. A lug 103 carried by the yoke 101 is urged by a spring 99 into engagement with an abutment on the arm 95. The shaft 88 is oscillated by linkage (Fig. 15, not shown) actuated by the cam shaft 29 so as to bring the rollers 93 into and out of operative relation with the rolls 92. The spring 99 allows the rolls to separate in the case of more than one bag being inadvertently presented to the rolls. The bag is next engaged by a further pair of driven feed rolls 106 carried by a shaft 43 connected by a chain drive 49 with the shaft 42, and a pair of idle rolls 107 carried by a shaft journalled in arms 109. The arms 109 are pivoted at their forward ends to plates 44 forming downward extension of the plates 34. Movement of the rolls 107 toward the rolls 106 is limited by an adjustable stop 110 on each arm 109. Movement of the rolls 107 away from the rolls 106 causes rotation of a shaft 117 (journalled between the plates 44) through the medium of cranks 116 the outer end of each of which is pivotally connected with a screwed shank 115 which passes through an aperture in the respective arm 109 and carries stop nuts 119. The shaft 117 carries a plurality of bag-deflecting fingers 118. If more than one bag is inadvertently fed from the stack, in passing between the rolls 106, 107 the rolls 107 are forced upwardly and consequent rotation of the shaft 117 (via. the arms 109, shanks 115 and cranks 116) causes clockwise rotation of the deflecting fingers 118 to engage the leading edge of the bags and turn them away from their normal path (Fig. 11, not shown). The bag transfer devices. The primary cradle E consists principally of members 121, 122, 129, 156, and is mounted by two vertically spaced sets of rollers 128 for vertical travel relative to the pillars 6 in timed relation to the bag feeding mechanism, by connection with a link 19 (Fig. 2) which derives a reciprocating movement from a main cam shaft 9 coupled to the motor 8. Each set of rollers comprises horizontally spaced pairs in respective engagement with the pillars 6 (Fig. 33, not shown). The secondary cradle comprises a carriage 133 mounted on the frame E for horizontal travel, by four pairs of rollers 136 which engage rails 131, 132 rigid with the frame E. Travel of the carriage 133 is brought about by means of a chain 210 secured at its upper end at 211 to one of the pillars 6 and at its lower end to a link 16 which derives reciprocating movement from a cam on the shaft 9. The chain 210 passes over sprockets 212, Fig. 22, freely mounted on the frame E and has a bight between the sprockets 212 which engages with a sprocket 213 freely mounted on one arm 207 of a bell crank 204 which is pivotally mounted on the frame E. The extremity of the arm 207 is connected with the carriage 133 by a link 209. The end of the other bell-crank arm 206 is connected by a tension spring 208 to a fixed point on one of the pillars 6. Each bag is initially received on the frame E from the feed rolls 106, 107, by a receiver 114 which is rigid with the frame E and has front and rear tapered sides 115', 116' an end wall 117', but is open on the side facing the end wall 117'. The bag is pressed into register with the end wall 117' by the outer end of an arm 225 (Fig. 22, and Fig. 37, not shown) which is pivotally mounted on the frame E and is connected by a chain 226 with a point 227 on the carriage 133 so that when the latter reaches the limit of its travel to the right when viewed as in Fig. 22 (in which however, it is shown at the leftward limit) the arm is drawn into engagement with the bag. The forward side of the bag is at this stage, engaged by suction cups 140 connected via a pipe 141 and the valve 182 with a source of vacuum, and mounted at 139 on the carriage 133. The rearward side of the bag is engaged by suction cups 142 similarly connected with the valve 182 but mounted on a bar 144 which has a downwardly cranked portion 143 which is rigid with the end of a lever 145 (Fig. 6). The lever 145 is pivotally mounted to a depending frame member 146 secured at 138 and 147 to the carriage 133. The forward end of the lever 145 carries a cam follower 149 which engages a cam track 158 in a plate 155 which is rigid with the member 156 of the frame E. The forward end of the lever 145 is urged in a downward direction by a spring 150 but is retained in an u