Patent GB-519322-A (GB)
Abstract: 519,322. Frictional shock-absorbers for irre versible power transmission mechanism. VICKERS, Inc. Sept. 20, 1938, No. 27341. Convention date, Sept. 30, 1937. [Class 108 (iii)] .[Also in Groups XXI, XXXIII and XXXIV] A mechanical power-control device adapted to prevent kick-back and overhaul forces from acting on a power shaft such as that operating dirigible wheels or rudders comprises a power input shaft, a power output shaft, the rotation of which is controlled by the input shaft, means connecting the shafts to permit of relative rotation, frictional braking means normally independent of the shafts, and means to engage the braking means with the output shaft when the output shaft is subjected to sudden torque impulses. As shown in Fig. 1 power is transmitted to a shaft 13 by a shaft 9 driven by handwheels 5, and gears 6, 7, 8, the gear 6 being connected with an inertia governor or fly-wheel 10. The shaft 9 is slidably connected by splines to a shaft 19 housed in a bore in the shaft 13 and also drives the shaft 13 by a block 12, Fig. 3, loosely fitted' in a slot 14 in the shaft. The block contacts with the sides of the slot by spring-pressed buttons 16 to form a resilient drive. The shaft 13 is mounted in bearings 18 in a casting A and is fitted externally with sliding clutch actuating plates 29, 30 drawn together against rollers 31 by springs 32. The rollers 31 are mounted on a pin 20 secured in the shaft 19 and slidably mounted in grooves 21, 22, Fig. 4, in the shaft 13 whereby relative movement between shafts 19, 13 cause the plates 29, 30 to slide along the shaft and engage one or the other of clutches 23, 24. These clutches each comprise an end' plate 28 and friction discs 25 splined to the shaft 13 and interposed between the discs 25 are friction discs 26 secured to a ring 27 the periphery of which forms a braking surface for a brake shoe 35 pivoted at 37 and-adjustable by a spring bolt 39. In operation the shaft 9 transmits rotary motion to shaft 13 through springs 17. If a kick back occurs' springs 17 compress and angular movement takes place between shafts 9, 13 turning the pin-20 in the slot 21 or 22 to move plate 29 or 30 to actuate the corresponding clutch and absorb the shock by friction of the brake shoe. When the energy has been absorbed spring 17 expands and restores block 12 to its normal position thereby moving pin 20 to disengage the clutch and free the shaft 13. In Fig: 5 the apparatus is shown applied to. the elevating &c. gear of a gun through a coupling 41. The coupling 41 is mounted on a shaft 42 and is driven eitherby a hydraulic follow up device consisting of remote control 43 driven by handwheel 44 through gears 45 and hydraulically connected to a variable piston displacement motor 46 connected by gears 47, 48 to the shaft, or by manual operation of shaft 44a, gears 49, housing 50 and gears 51, 48. The housing 50 is connected to the gears 51 by spring-pressed buttons 65 and a splined shaft 62 slidable in the gear 51 is connected at one end to the. housing 50 by pin and slot 67, 66 and at the other end to a lever 61 which when relative movement between the housing 50 and gear 51 occurs, operates a sliding block 58 on shaft 42 to move brake actuating discs 59 or 60. These discs are slidable on sleeves 52, 53 separately connected to the shaft 42 by free wheel clutches 56, 57 which allows the sleeves to be rotated in one direction only and in opposed directions. When operating the gear manually the clutch C is moved to the position shown and the rotation of the handwheel operates shaft 41 through the gears and. also moves housing 50 relatively to gear 51 to, say, lower the shaft 62 and place block 58 in contact with brake disc 59. When kick back occurs the free wheel clutch 56 engages with the shaft 42 and the shock is absorbed by brake 52. A brake 68 on shaft 44a is released by a pedal 70 when handwheel 44 is to be operated.