Patent GB-452024-A (GB)
Title: Improvements in or relating to heel breasting machines
IPC: A43D87/00
Filed: 1935-02-15
Abstract: 452,024. Boot making machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., Union Works, Belgrave Road, Leicester.-(United Shoe Machinery Corporation ; 140, Federal Street, Boston, U.S.A.) Feb. 15, 1935, No. 4854. [Class 17 (i)] Breasting.-In order that the breasting knife may cut completely through the heel without penetrating the sole, a knife actuator having a constant stroke is given variable lost motion at the beginning of its stroke, shank engaging means operating in advance of the knife gauging the limit of the knife stroke and connections between the shank engaging means and the knife actuator predetermining the effective stroke of the actuator. The sole materials in line with the breasting knife are compressed by power prior to the cut, so that they may not give to the thrust of the knife. The shank presser and a heel tread plate are depressed with substantially equal pressures. A heel stop partially embraces the back of the heel to prevent the shoe tipping backward when the usual breasting knife, bevelled on its forward surface, is used. The breasting knife 20, Fig. 1, is adjustable in a head 54 by a screw 65, and is guided in grooves in plates 58, 59, one of which can be slid downwardly and outwardly on slackening a clamping screw 64 to allow exchange of the knife. The head 54 is carried on rods 56 slidable in bearings 68, 72 and formed near their lower ends with grooves for the reception of an actuator 24. This assembly is normally held raised by a torsion spring 50, Fig. 3, the ends of which engage links 80 pivoted to the actuator. The spring is carried by a sleeve journalled on the hub of a link 48 connecting a crank-pin 42 of a power-driven cam-shaft 40, with the actuator. The link 48 is secured to a member 76, Fig. 7, providing clearance for a quick-pitch screw 44 pivoted to the actuator, the screw engaging a nut 46 supported by rolls 100 carried by a fork on a pivot 104, Fig. 3, carried by an arm 96, Fig. 1, pivoted to the frame of the machine and urged upwardly, to press the nut against the member 76, by a spring 102. The free end of the arm 96 carries a cam 108 which is engaged by a roll 110 when the crank-pin 42 is in starting position, the nut 46 being thus depressed. The shank presser 26, Fig. 5, is self-adjusting to the shank about a pin 120, Fig. 10, and is carried by a post 84, Fig. 2, vertically slidable in a head 86, and carrying at its lower end an arm 88 engaging the pivot 45. The post is connected by a spring 92 with a treadle 90, Fig. 1. The tread clamp 32, Fig. 10, is formed with a rounded rib self-adjusting in a corresponding recess in a plate 126, these members being held together by a pin 138 carrying a cross-pin 142. The plate 126 is adjustable longitudinally of the shoe by a screw 130 engaging a plate 128 carried by a post 162, Fig. 2, slidable vertically in the head 86. Both posts 84, 162 are formed with ratchet teeth 166 co-operating with pawls carried by members 176 depending from either side of a rocking carrier 178 secured to a rod 180 carried by the sliding head 86. Bifurcated extensions 188 guide the pawl carriers. A spring 200 normally holds the pawls out of action, a cam actuated rod 210 rocking a bellcrank lever 202 carrying a pin having a V-notch engaging a correspondingly shaped end of the rod 180, this arrangement tending to centralize the two pressers. The head 86 is carried by a rod 164, Fig. 3, urged downwardly by a spring 34 against a cam actuated arm. The heel stop 36, Fig. 10, is carried by pivot pins 144, Fig. 5, maintained by springs 144 in notches at the end of a yoke provided with rods 154, Fig. 2, resting on the plate 32. The shank 158 of the yoke is pivoted to rods 160 the upper ends of which engage the curved underside of a clamping plate 266, their lower ends being pivoted to the rear end of a lever 262, Fig. 3, the forward end of which engages the jack. The jack comprises a toe rest 272, Fig. 2, slidable up and down and also angularly adjustable about a clamping screw having a hand wheel 280, Fig. 1, and a short last pin 288, Fig. 2, all carried by a tube 234 movable forwardly and rearwardly by engagement with grooved rollers 240, 242 carried by a frame 30 urged upwardly by a spring 232 to a limit determined by a stop 252, Fig. 4, carried by a bell-crank lever 246 pivoted to the frame. Ribs 256 on the jack are guided by rolls 254 on a yoke secured to the lever 262, this lever itself being engaged by the lower end of the heel post when the jack is in operative position. The machine is driven by a Horton clutch, an arm 302, Fig. 3, on a rookshaft 304 disengaging the clutch at the end of a revolution. The rock-shaft is actuated by toggle links 310, 312, Fig. 1, the latter having a tail engaged by a cam 308 to straighten the toggle after the clutch has been tripped. The pivot of the toggle carries an arm 318 urged by a spring 324 into the path of a plate 322 on the treadle. A pin 330, engaged by the cam, returns the arm after the clutch has been tripped. A brake shoe 332 engages an eccentric to hold the camshaft in starting position. A hand wheel 292 adjusts a stop 287 to determine the starting position of the actuator 24. In operation, all adjustments having been made, a shoe is positioned on the jack and this is pushed rearwardly into the machine. If desired the jack may be swung about the tube 234 properly to position the heel. The treadle is then depressed, permitting the breasting knife to descend by the weight of its connected parts until the knife rests on the heel. Simultaneously, the shank presser and heel tread plate descend, the post 162 supporting the latter normally resting on a guide bar 163, Fig. 2, secured in the post 84 and engaging a groove 167 in the post 162. Further depression of the treadle, after the knife has engaged the heel and until the shank presser reaches the sole, causes the actuator to leave the upper end of the grooves in the rods 56, the extent of such travel depending on the height of the heel to be breasted. Continued depression of the treadle trips the clutch, whereon the cam-shaft commences to rotate, first advancing the pawls into engagement with the teeth 166 on the rods 84, 162, and then releasing the spring 34 to clamp the shank presser and heel plate upon the shoe. The base of the heel post is thus forced downwardly against the thrust of the spring 232, engaging the lever 262 and locking the upper ends of the links 160 against the plate 266, these links providing an abutment for the stop 36, against the thrust of the heel during the breasting stroke. During this descent of the actuator 24, the nut 46 spins to allow the screw 44 to descend ; but, at this point, the cam 108 leaves the roll 110 and allows the spring 102 to bring the nut 46 into contact with the member 76, providing an unyielding connection between the crank-pin 42 and the knife actuator 24. The actuator, thus, descends, first taking up the lost motion, and, on reaching the lower end of the.grooves in the posts 56, imparting a measured cutting thrust to the breasting knife. During the return of the crank-pin 42 to its upper position, all parts of the machine return to starting position.