GB505059A - Improvements in time-measuring escapement mechanism for clocks and watches or other purposes - Google Patents

Abstract

505,059. Clocks and watches. KING, N. R. March 16, 1938, Nos. 8101 and 14600. [Class 139] A lever escapement is so constructed that in one direction of motion of the impulse roller or pin 7 the pallets are unlocked and an impulse given to the balance, whereas there is no impulse in the other direction. One of the horns of the fork is resilient, Fig. 4 (not shown), or resiliently mounted, Fig. 1, in one direction so that in returning, after the unlocking movement, the impulse roller or pin wipes freely past this horn. In another construction, Fig. 3, the fork 9, 10 is solid and the roller 7 carries a spring blade 18 which, clockwise, wipes past horn 10. The horn 10, Fig. 1, is pivoted at 13 to the lever 4 and biassed clockwise to a limiting position by a spring 16. As the roller 7 on the balance staff 8 oscillates clockwise it merely wipes past the horn 10, leaving the escape wheel 1 in the looked position shown. On returning counterclockwise the roller 7 meets horn 10 and rocks the lever 4 so that pallet 2 unlocks the wheel 1. The latterthen, through the impulse face of pallet 2, causes horn 9 to give an impulse to the roller 7. The latter. passes horn 10 and a scape tooth directly meets the impulse face of pallet 3 (which never locks wheel 1) and returns the lever 4 to the locking position shown as the roller reaches its end position 7c. The coacting surfaces of horn 9 and roller 7 are so shaped that a rblling action takes place between them.