Patent GB-531516-A (GB)
Title: Improvements in or relating to broaching machines
IPC: B23D37/04
Filed: 1939-07-25
Abstract: 531,516. Broaching. SUNDSTRAND MACHINE TOOL CO. July 25, 1939, No. 21587. Convention date, Oct. 10, 1938. [Class 83 (iii)] A broaching-machine has a work support 20 secured to a vertical frame member 12 along which the broach is reciprocated by a ram, the frame member being provided with a shaft 13 mounted in bearings 14, 15 in the machine column 10 so that the frame member may be inverted. The ram 16, moving along ways on the frame member, carries a puller head 19 fitted with a chuck 24 adapted to pull the broach 23 upwardly, Fig. 1, through the work. After disengagement from the puller head, the broach is lifted by a lifter 22. A reservoir 30 in the column supplies fluid to a pump 33 driven from a motor 38 and having high and low pressure portions 34, 35 respectively. The motor is pivotally supported at 45 and may be moved round the pivot by adjusting screws to tension the belt. The frame element may be bolted to the column in the position shown in Fig. 1 by bolts passing through flanges on the frame. One end of the shaft 13 is fitted with a worm wheel 57 driven from -a horizontal shaft 59 driven from a hand crank for swinging the frame through 180 degrees to change from pull-up to pull-down operation. A stub 141 secured to the frame by bolts is seated in a recess 143 in the shaft 13 to locate the shaft on the column. The ram cylinder 62 is reciprocated over a piston 63 secured by a tubular piston rod 64 to a block 65 mounted on the frame. The block has two ports one, 67, leading through the rod 64 and ports 68 to the lower side of the piston, and the other 70, leading through a central hollow tube 69 to the upper side of the piston. The work support has a horizontal wall which is bored to receive a work bushing 76. The broach lifter comprises a movable cylinder 80 moving over a stationary piston 81 mounted on a hollow rod 82 secured to a block 83, the cylinder being integral with a slide moving on spaced guide rods 86. The block 83 has ports 91, 93 communicating respectively with the lower and upper ends of the cylinder. The broachreceiving member 97 is preferably provided with a detent device 97<SP>1</SP> to support the broach when the machine is used for pull-down broaching. A table 100, secured to the frame member 12 below the work-holder has an inclined surface 101 to discharge the work pieces forwardly from the machine. Coolant discharged on to the broach from a nozzle 103 falls into a receptacle 102 whence it is circulated through a delivery pipe 110 by a pump 104 driven by a motor 105. The supply pipe may be broken by couplings 109 when the machine is converted from pullup to pull-down operation, one of the couplings being connected to one end or other of a horizontal stretch 110 of the supply pipe. Fluid is supplied to the ram and lifter cylinders through the shaft 13 which has longitudinal passages 112, 113 connected at one end by lines 114, 115 to the ports 91, 93. The other ends of the passages terminate in radial ports 116, 117. The shaft 113 has a number of rings 118 ... 121 providing annular fluid spaces, these rings having external connections 126 ... 129 connected to the supply pumps 34; 35 as shown in Fig. 9. The line 152 from the pump, leads to a solenoid-operated four-way valve 153 from which lines 155. 156 lead to the rings 126, 127 which are connected by lines 131, 132 to the ports 70. 67 respectively. The pump 35 supplies fluid to another solenoid-operated valve 161 connected by lines 164, 165 to the rings 120, 121 connected to the lifter cylinder. A valve 160<SP>1</SP> in this circuit may set to byepass the pump delivery to a line 182 to render the lifter inoperative. In Fig. 1 the machine is arranged for pull-up broaching of the usual kind and to change the machine over to pull-down broaching the frame 12 is unbolted the coolant couplings disconnected the frame turned'through 180 degrees by the gearing 58. the bolts replaced, and the coolant connections re-made. For pull-down broaching Fig. 4. the broach is pulled through the work by the head 19 and subsequently pulled upwardly by the lifter head. The machine may also be used for pull-down surface broaching the head 19 and lifter being. removed and a surface broach attached to the front face of the ram 16.