Patent GB-418223-A (GB)
Title: Improvements in or relating to stitching machines
IPC: D05B75/00
Filed: 1933-04-20
Abstract: 418,223. Stapling. BOSTON WIRE STITCHER CO., Division Street, East Greenwich, Rhode Island, U.S.A. April 20, 1933, No. 11614. Convention date, April 21, 1932. [Class 89 (iii).] A stitching or stapling machine particularly for stitching filled fibre-board containers, comprising a stitching head 4 carried by a post 2 and a table 60 for supporting the containers, is provided with power means including a releasable clutch and a friction brake for raising the table to a correct height for the stitching operation. The stitching head is driven by a continuously-running electric motor 6 through gearing 10, 11 and a clutch controlled by a treadle. The table 60 is adjustable on a supporting frame 62 carried by a frame 65 having rollers 63 running on tracks on the post 2. The frame 65 is raised up the post 2 by a chain 6, 8, Fig. 11, which is fixed to the frame 65 and runs over sprocket wheels, the upper of which 69 is adapted to be clutched to a sprocket wheel 67 continuously driven from the gear 11 by a chain 66. This clutch is under the control of the operator through a treadle 82, and is also opened automatically by a feeler device 130 which contacts with a container on the table when the latter is fully elevated. The table is held in raised position by a brake and is returned to lowered position by gravity under control of a dash-pot. The clutch for connecting the main shaft 12 of the stitcher head to the gear wheel 11, Fig. 7, comprises friction discs 13, 14 keyed to the wheel and shaft. Clutching pressure is applied to the discs by a ring 17 formed with cam surfaces 18. These are adapted to be engaged, for forcing the discs 13, 14 together, by the ends of arms 23 pivoted to a sleeve 21 pinned to the shaft 12. A sleeve 20 mounted to slide along and rotate with the sleeve 21 carries pins 25 co-operating with the arms 23. Normally, the sleeve 20 is held to the right by a cam 51 on it engaging a block 52 on a rod 53 linked to the first-mentioned treadle. When the treadle is depressed, the sleeve 20 is moved to the left by springs 47. The pins 25 then rock the arms 23, which force the clutch discs 13, 14 into engagement, so that the shaft 12 is driven. When the treadle is released and the sleeve 20 is forced to the right, releasing the clutch, spring plungers 50 carried by the sleeve force the friction discs 31, 32 of a brake into contact, thereby rapidly arresting the shaft 12. The block 52 is eccentric and adjustable on the rod 53. The gear wheel 11 carries the upper sprocket wheel for the chain 66. The lower sprocket wheel 67 for this chain is adapted to be clutched to a shaft 72, Fig. 8, which carries the sprocket wheel 69 by clutch discs 74, 76. These are forced into engagement by a cross-pin 77 and a rod 79 extending through the shaft 72 and controlled by a rocker 80. The latter is controlled by the treadle 82 through linkage 83, 84, 85, 86, Fig. 11. The rocker normally is held in declutching position by a spring 89. When the treadle 82 is moved to position B, Fig. 1, the rocker 80 forces the rod 79 to the left, clutching the shaft 72 and sprocket wheel 69 to the sprocket wheel 67. The chain 68 then elevates the table 60 until the shaft 72 is declutched. The table is held in elevated position by a brake engaging the shaft 72. This brake, Fig. 13, comprises a drum 102, a brake shoe 100 connected by pull links 106, 107 to a link 105, and a shoe 101 connected to link 105 by a push-rod 108. The link 105 is so biassed by a spring 103 that normally the shoes are in contact with the drum. A one-way drive connection 110, 111, 112 allows the shaft 72 to rotate freely within the drum 102 in a direction to elevate the table, but prevents reverse rotation of the shaft, and consequent lowering of the table. The brake shoes are released from the drum by moving the treadle 82 to the position A, Fig. 1, the link 85 being connected to the link 105 by a push rod 115. When the brake shoes are released, the table can descend under gravity, such descent being controlled by a dash-pot arrangement 120 and limited by a spring stop 125. Means for opening the elevating clutch automatically comprises a feeler 130 which is pivoted to the stitcher head and is connected by links 133, 134, 135, 136 to the rocker 80. In operation, the operator places a container to be stitched on the table 60, and presses the treadle 82 to position B. The table is then elevated by chain 68 until the operator releases the treadle or the container engages and rocks the feeler 130. This disengages the elevating clutch, the brake drum 102 then holding the table in raised position. Pressure on the stitcher treadle then clutches the stitcher shaft 12 to the motor 6 and the container is stitched. When the stitcher treadle is released, the brake discs 31, 32 rapidly arrest the stitcher shaft, and movement of the treadle 82 to position A finally allows the table to descend under gravity.