Patent GB-548602-A (GB)
Title: Improved machine for making poppet valves
IPC: B21K1/22
Filed: 1941-09-19
Abstract: 548,602. Gearing for starting and stopping machinery. GENERAL MOTORS CORPORATION.. Sept. 19, 1941, No. 12023. Convention date, Nov. 28, 1940. [Class 80 (ii)] [Also in Group XXII] Poppet valves are forged from rod blanks that are placed in a die and acted on by a series of punches that form a conical end in three stages, flatten the end to valve head form and finally hollow the upper surface of the head. The dies are carried by an indexed rotary carrier and the punches by a sliding head reciprocated by an eccentric on a shaft driven from a self-contained motor through reduction gearing and a clutch. The clutch 29, Fig. 16, is normally maintained engaged by springs 33 but on removal of the foot from a pedal a lever 55 permits the spring 47 to raise a head into the path of a lever 37, pivoted in a lug carried by a flange 35 on the press shaft, thus withdrawing the clutch part 29 and stopping the press. The press head 73, Fig. 2, carries two rods 75 that in the descent of the head enter'holes in the rotary die carrier. On the upstroke of the press an arm 113 attached to the head moves a collar 115 idly up a reduced part 117 of a rack bar 121 until the rods 75 are free from the carrier. The collar then engages a head 119 and turns the pinion shaft 125 so that a spring pawl 129 rotates a notched ring 131 attached to a bevel pinion 127 gearing with a wheel 128 secured to the die carrier. An index bolt 135, held at first out of engagement with the notch 133 by a roller 143 engaging the rack bar, rides on the periphery of the ring until the next notch comes into locking position when the bolt snaps home under the pressure of spring 139 as permitted by the recess 141 in the rack bar. On the down stroke of the press the pawl 129 returns idly and when the die carrier is again locked by the rods 75 the inclined end of the notch 141 cams the bolt 135 free of the notched ring completing the indexing cycle. Heated blanks are supplied to a holder 101, Fig. 6, and at the end of the up stroke a cam slot 99 engages a pin 91 moves a guide block 97 under the holder 107, and the blank falls into the passage 105. At this time a lever 107, Figs. 2 and 6, is rocked about its pilot 109, enters a slit in the passage and moving faster than the press head forces the blank to the bottom of the base 85 below a die 87 having the shape required for the underside of the head: At the next station a hollow punch 106 gives the end of the rod an elongated conical shape. At the third and fourth stations the conical end is increased in diameter and shortened, at the fifth it is flattened to valve head form, at the sixth the upper surface of the head is hollowed and at the seventh the finished valve is ejected by a rod 151 operated by a lever 135, Fig. 2, linked to the lever 107. Spring clamps 163, Fig. 4, operate through slits in the bushes 85 to hold the blank during the forging operations and the spring is set free between the loading station and the first forging station by a cam sleeve 175 rotated by a lug 177 wiping over a pin during indexing of the die carrier. The spring is similarly compressed as the. die indexes to the ejector station.