Patent GB-443646-A (GB)
Title: Improvements in winches and like hoisting apparatus
IPC: B66D1/14
Filed: 1934-09-03
Abstract: 443,646. Winding-apparatus. QUICK, A. A., 75, Penders Street, Thornbury, Victoria, Australia. Sept. 3, 1934, No. 25359. Convention date, Sept. 8, 1933. [Class 78 (v)] A winch or hoisting-apparatus comprises in combination a winding drum, a spur gear-wheel fast with the drum, a pinion meshing with the gear-wheel, a frictional clutch mechanism for connecting the pinion to a power shaft, and ratchet mechanism arranged in series with a friction brake for normally preventing reverse or unwinding movement of the winding drum. In the construction shown in Fig. 1, a continuously-driven pulley 17 is fixed on a shaft 7 carrying a pinion 6 which is normally loose on the shaft but can be clutched thereto so as to drive a gear-wheel 5 fixed to the winding drum 1. A second pinion 8, also in mesh with the gear-wheel 5, is mounted loosely on a shaft 9 and is normally clutched thereto, this shaft being prevented from turning backwards by a pawl 45 mounted on a fixed pivot and engaging a ratchet wheel 44 on the shaft. The clutches connecting the pinions 6, 8 to their shafts are controlled by a hand lever 23 pivoted to another lever 21. When the hand lever is released pinion 6 is loose on its shaft so that the winding drum is not driven, and pinion 8 is clutched to its shaft and thus prevents the winding drum from running back. To raise the load the lever 23 is moved in the direction of arrow A, this moves the shaft 7 axially and clutches pinion 6 to the shaft so that the drum 1 is driven by pinion 6. To lower the load the lever 23 is moved in the direction of arrow B so as to rock lever 21 counterclockwise and pull rods 40 to the left thereby partly or completely de-clutching pinion 8 from shaft 9, which is held stationary by the pawl 45, and allqwing the load to turn the drum 1 under control of the clutch acting as a brake. In the construction shown the pinion 8 is combined with a multi-plate clutch or brake having inner plates 11<1>, Fig. 6, splined on the shaft 9 and outer plates 101 which form the pinion teeth. The plates 101, 11<1> are located between collars 24, 25, respectively fixed and loose on the shaft and are pressed together, to clutch the pinion to the shaft, by springs 36 acting on the collar 25 through a slidable collar 35 splined on the shaft and a housing 33 loose on the shaft. When the rods 40 are moved to the left the springs 36 are compressed and the pinion tooth plates 10<1> slip on the shaft which is held stationary by the pawl 45. To prevent the load from being lowered too quickly, the collar 25, which is fixed to one of the plates 101, carries pivoted weights 31, Fig. 2, controlled by a spring 31<11>, so that when the speed of the pinion becomes excessive these weights fly out and engage the rim of the housing 33. This causes the housing to rotate relatively to the collar 35, whereupon cam teeth 34 between the collar and housing force the housing to the right to increase the braking action between the plates 10<1>, 11<1>. The driving pinion 6 is combined with a multi-plate clutch constructed similarly to the pinion 8, the clutch plates being normally held disengaged by tension springs 16 anchored at one end to the pulley 17, and therefore to the shaft 7, and at the other end to a sleeve 13 bearing against the clutch plates. When the shaft is moved to the right by the lever 21 a collar 12 fixed on the shaft presses the clutch plates together, the sleeve 13 having a bearing against a thrust bearing 14. When the load is being hoisted the pawl 45 is kept out of contact with the ratchet wheel 44 by means of a friction plate 50, Fig. 4, connected by a link 48 to the pawl and pressed by a spring 51 against the rotating wheel 44. The disengaging movement of the pawl is limited by a stop 47. The following modifications are described : (1) In Fig. 9 (not shown), the centrifugal means for controlling the lowering speed are dispensed with. (2) In Fig. 10 the pinion 6 is connected to the driving shaft 7 by a cone clutch 56, and the pinion 8 and ratchet wheel 44 are both fixed to shaft 9, the ratchet wheel being engaged by pawls 45<1> pivoted to a loose brake drum 58 normally held stationary by a spring-loaded brake band 60. Thus, when the load is being hoisted; the shaft 9 turns and the ratchet teeth run under the pawls 45<1>. When the driving clutch 56 is disconnected, the pawls prevent the load from running back. Lowering is effected by releasing the brake 60 by means of a hand lever. (3) In Fig. 12 (not shown), one of the shafts 7, 9 is dispensed with, the driving pulley 17 being loose on its shaft and connected to the pinion 8 by a clutch such as 56. This arrangement is otherwise similar to that shown in Fig. 10. (4) In Fig. 13 means are shown for driving the winch drum in the reverse direction to pay out the unloaded hook. A grooved friction roller 70 is carried by links 69 depending from a lever 66 pivoted at 46 and is adapted to engage a roller 71 on the driving shaft 7 and the end flange 3<1> of the winding drum 1 so as to drive the drum in the opposite direction to that in which the usual spur gearing drives it. The lever 66 is operated by hand after the spur gear drive has been de-clutched by the hand lever 23, or the levers 23, 66 may be connected together by a bell crank 73 so that the lever 23, when moved in the opposite direction to the movement required for giving the normal drive, operates the lever 66. When the reverse gear is in operation a spring finger 72 carried by the lever 66 bears against the housing 33 and prevents any rotary movement of this housing which might cause the brake plates 10<1>, 11<1> (not shown) to be brought into engagement.