Patent GB-498262-A (GB)
Title: Improvements in and relating to toothed gearing for actuating winches, sluice valves, and the like
IPC: E02B7/36
Filed: 1937-11-22
Abstract: 498,262. Toothed gearing. STRUBE, C. Nov. 22, 1937, No. 32072. [Class 80 (i)] In transmission mechanism incorporating differential gearing and a stress - limiting or slip device means are provided whereby the limiting stress can be varied, particularly according to direction of rotation. Preferably a non-reversible drive is placed between the drive shaft and the differential and the slip device is mounted on a movable element such as a sun gear. Fig. 2 shows mechanism for operating a sluice gate 4 in which the slip device comprises a grooved drum 16 adapted to engage with two spring bands each having one end terminating in a spiral 221, Fig. 3, and the other end rigidly secured at 19<1> to the casing 20. If one band is loaded more or is wider than the other, or acts with greater leverage the stress limit will be different according to the direction of rotation. This will also result with one spring in view of the different anchorages of the ends. Non-reversible drives are given by worms 5<1>, 5<2> in mesh with wheels 6<1>, 6<2> fast to the casings 71, 7<2>. The drum 16 is fast on the spindle 15 of the sun gear 13<2>. The friction of the band 181 may be varied by moving the bearing pin 23<1> of the spiral end circumferentially. Braking may alternatively be effected by the device shown in Fig. 10. The shaft 2<1> carries a, quick-pitch worm 5<1> and a disc 26 adapted to rotate between friction bands 28 of different width. The shaft has axial play e so that the thrust on the worm brings the disc into contact with one or other band 28 according to direction of rotation. Other slip devices for use on the shaft 2<1> in conjunction with a hand wheel comprise spring-pressed balls or bevelled bolts engaging grooves in a disc secured to the casing 21, Fig. 10, the sides of the grooves being differently sloped to give different stress limits. A single shaft 21 may be used in which case it acts through a worm on a wheel secured on the spindle of a sun wheel of a single differential. Retractable locking means may be combined with the sun 13, which may be locked for actuation of the shaft 1 or released to make it independent of the shaft 2 and ensure its return to initial position, Fig. 18. The frame 7 of the differential is driven by a motor on the shaft 22. The shaft 2 is extended to receive a slip device 41 of any of the kinds described, and a pinion 42 in mesh with a gear 43 carried by a drum 44 loose on a shaft 45. A latch 49 pivoted at 50 and actuated by a solenoid 54, in the motor circuit engages the gear 43. A weighted cable 56 wound on the drum urges it to rotate. Normal actuation of the gate 4 is effected by the motor but may also be effected by hand through the shaft 2. If the current fails the rod 53 is released and the gear 43 unlocked so that the drum 44 is rotated by the cable and thence the shaft 2 and gate 4. Rewinding is effected by means of a pinion 57 driven by power which is meshed with a gear 58 on the drum by moving the latter to the left by means of a lever 59, the pinion 42 being simultaneously disengaged from the gear 43.