GB489711A - Improvements in or relating to machines for staking, softening and similarly treating hides, skins, leather and the like - Google Patents

Abstract

489,711. Leather-working machines. TURNER TANNING MACHINERY CO., Ltd., and SCHETTLER, G. A Feb. 2, 1937, No. 3035 [Class 76] In a machine for staking or softening leather of the type comprising a pair of jaws, which are reciprocated and moved to and from each other synchronously with their reciprocations, so as to stretch and bend the leather over tools carried by the jaws, means are provided whereby the relative movements of the jaws can be gradually nullified and gradually restored during the reciprocation. In the machine shown in Fig. 1, staking tools 13a, 14a, are mounted on arms 13, 14 pivoted at 23, 24 on a crosshead 16 supported on parallel swinging arms 32, 33 pivoted at 34, 35 in the frame 1. The reciprocatory and opening and closing movements of the arms 13, 14 are effected by means of a connecting rod 11 mounted on a crank pin 8 driven by a pulley 9 and pivoted at 15 to links 17 pivoted at 18 to the crosshead. The connecting rod 11 carries in fixed relation a cam 12 which bears on a roller 31 mounted on the arm 14. The cranked ends of the arms 13, 14 are connected by a link 25 and an adjustable spring 28 is provided to keep the roller 31 in contact with the cam. The links 17 are connected by a link 20 to a treadle 22 by the operation of which the links 17 are moved about their pivot 18 and the pivot point 15 of the link 11 is raised so that the cam comes into contact with the roller 31 and effects the opening and closing of the arms 13, 14. When the treadle is released the arm 14 drops into contact with a stop 30 and the tool then reciprocates without contact with the work carried by the divided tables 58. The link 20 is normally parallel to the links 32, 33, and the pin 15 in its movement follows the same general arcuate path as the crosshead and the tools 13a, 14a describe a parallel sided path. The lower end of the link 20 is however horizontally adjustable in the treadle and when so adjusted to one side or the other the path of the pin 15 is inclined somewhat to the path of the crosshead and the tools describe paths slightly tapered to one end or the other of their stroke. In a modified construction, Fig. 3, the crosshead moves in slides 60, and the links 17 are supported by a roller running on a track 62, which can be moved vertically by mechanism 63-67 and also tilted. The movement of the treadle is limited by a stop 53 against which the treadle may be pressed by the operator, but an auxiliary treadle 22a may be provided on the treadle shaft and when this is employed a yielding pressure is applied to the work due to the torsional resilience of the shaft. The work is clamped during the working stroke by an arm 38 operated synchronously with the staking mechanism by means which may be as described in Specification 489,748. Staking tools of the construction shown in Fig. 5 may be mounted on the bars 13, 14 comprising knives 73, 74, 75 and rollers 69, 70.