| 摘要 |
699,226. Grinding machines. BRYANT CHUCKING GRINDER CO. May 2, 1952 [June 7, 1951], No. 11162/52. Class 60. A grinding machine includes a rotary workholder 1, Fig. 6, a grinding wheel 4 on a reciprocable support 3, means to reciprocate the support and a device movable from and to a position between the means and the support, the device having a mounting comprising a pair of members 26, 28, Fig. 1, yieldably held in alignment. An eccentric 20, Fig. 3, constitutes the means to reciprocate the support 3 which is connected by a bar 6 to one end of a lever 10 and urged to a position in which the grinding wheel 4 is clear of the work by a spring 7. The advance and retraction of the support 3 in relation to the work is effected by a cam (not shown) mounted on a shaft 13, Fig. 5, to cooperate with a follower 12 on the lever 10. A second cam 45 mounted on the same shaft periodically lifts a roller 40 which rocks the two members 26, 28, Fig. 1, against the action of a spring 50 and about a fixed pivot 29 to lower a bar 22 to a position between the eccentric 20 and a roller 24 journaled on the lever 10. The bar, which is spring-loaded and mounted for reciprocation in a sleeve 23, then transmits the motion of the eccentric to the support 3. If the space between the roller and eccentric is not sufficient to enable the bar to descend without shock, the member 26 yields about a pivot 27 and against the action of a spring 35 until the eccentric has rotated to a position in which the bar is able to descend. When the roller 40 falls under the action of the cam 45 to terminate the grinding operation, the bar 22 is retained in operative position by a stop 60 until a plate 67 reciprocated with the bar is at the rightward end of its travel, Fig. 3, when the bar is free of axial thrust and may be removed without shock. The plate 67 is adjustably clamped to a bracket 70 which is mounted on the bar 22 and fitted with a guide pin 72 riding in a lug 73. The stop is loaded by a leaf spring 61 which holds the bar in engagement with the eccentric as it descends. Specifications 678,188 and 678,202 are referred to: |
