Patent GB-191125920-A (GB)
Title: Improvements in or relating to Grippers Mechanism for use in the Manufacture of Boots and Shoes.
Inventor: BOULT ALFRED JULIUS
IPC: A43D23/02
Filed: 1911-11-20
Granted: 1912-11-14
Abstract: 25,920. Boult, A. J., [United Shoe Machinery Co.]. Nov. 20. Lasting.-A grippers mechanism for use, for example, in machines of the type described in Specifications 14,453/97 and 7005/00, is adapted to grip and pull corresponding portions of a number of layers of material, and to be capable of pulling one of these portions, such as the shoe lining, to a different extent from another, such as the shoe upper. In one construction, Fig. 1, the gripper casing 6 is forked at its lower end, and has secured to it a rigid jaw 2, and two pivoted jaws 8, 14, having upwardly-extending arms 12, 16 ; the jaw 14 and the arm 16 are formed separately, the hub of the one fitting into the bifurcated hub of the other, and being provided with a V-shaped recess into which fits an adjustable spring-pressed pin 18. The jaws are closed by the engagement between the arms 12, 16 of a roller 26 carried by a slide 25, and are opened again by the engagement respectively with the outer edges of these arms of a hub 27 and a pin 28, also secured to the slide 25. This slide is connected by a hook 29 to a camactuated operating-bar 30, between which and a cross-piece 42 of the casing 6 is interposed a spring 40. This spring is compressed when the bar moves downwards to cause the slide 25 to open the grippers, and holds the casing and the grippers down until the bar and slide have risen far enough to close the grippers on the stock, after which the jaws are lifted to pull the stock. The co-operating faces of the jaws 2 and 8, which engage the upper, are roughened to a greater extent than those of the jaws 2 and 14, which engage the lining ; this arrangement, together with the yielding connexion 18 between the jaw 14 and arm 16, permits the lining to slip after it has been pulled to the desired extent and while the upper continues to be stressed. In addition to, or in place of, the yielding connexion 18, the gripping-faces that engage the lining may be formed on adjustable spring-pressed sliding blocks ; when the slack has been taken out of the lining, these blocks slide in their seats, instead of the lining slipping through the grippers. In another construction, the inner jaw is rigidly connected to the gripper casing, and the intermediate and outer jaws are pivoted about the same pin. The grippers are closed by a roller, and opened by a hub on a slide, as in the previous construction, while the roller is also adapted, when the slide is lowered, to engage a seating in the intermediate jaw to hold the jaws open for the reception of the work. Figs. 10, 12, and 14 show another construction, in which only two gripper jaws 114, 116 are used. of which the former is adapted to engage the shoe lining. The jaw 116 is pivoted at 102 to a forked head 106 on a gripper bar 115, and is normally held open by a spring-pressed finger 108, which engages its upper arm a; a shoulder 112 limits the amount of movement effected by the finger. The jaw 114 is rigidly secured to a slide 130 mounted in an off-set portion 122 of a gripper-bar 113, which surrounds the bar 115. Between this slide, which is normally held upwards by a spring 135, and the arm a of the jaw 116 is a closing-device 120, which is pivoted to the off-set 122, and is adapted to be engaged by inclined faces b, c formed on the inner side of the jaw 116. The outer face of this device is furnished with a roller 121 adapted to ride on an inclined surface 125 of a block 124 adjustably bolted to the slide 130. In operation, the finger 108 holds the jaw 116 open while the bar 115 moves downwards, Fig. 12, until the face b meets the device 120, which causes the jaw to rock into contact with the upper, Fig. 14. As the jaw closes, the face b rides off the device 120 and the face c comes into engagement with it, while at the same time shoulders 143 on the head 106 engage shoulders 141 on the slide 130, causing the slide and jaw 114 to move downwards with the bar 115 and its jaw 116, while the bar 113 and the closing-device 120 remain relatively stationary. During this movement, the inclined face 125 of the block 124 forces the device 120 against the face c of the jaw, causing the latter to be closed firmly on to the upper. When the pulling movement takes place, the spring 135 enables the jaw 114 to yield downwards relatively to the jaw 116 to compensate for the difference in the elasticity of the lining and that of the shoe upper, but during this movement, the inclined face 125 forces the device 120 against the face c of the jaw 116, so as not to allow the grip on the stock to slacken.