GB173102A - Improvements in or relating to lifting and hauling gear - Google Patents

Abstract

173,102. Padfield, W. W. Oct. 11, 1920. Drum or barrel winding- machines; driving-gear; selfsustaining gear; geared pulley-hoists.-In a haulage gear the driving-shaft 3, Fig. 3, is connected to the winding- shaft 8<a> through two-speed gear, one high speed through gears 2, 7, the other slow speed through gears 1, 4, and means are provided for clutching the winding-shaft to either gear according to the direction of rotation of the driving- shaft, and to the weight of the load. As shown in Fig. 3 four clutches are provided, a Weston clutch 15 for the low gear when lifting heavy loads, a ratchet mechanism 11, 12 - for-the high gear when lowering, a clutch 22 for the high gear when lifting light loads, and a clutch 24, 25 adapted to rotate the shaft 17 until the Weston clutch functions when lifting heavy loads. A pinion 18 screwed on the shaft 17 is normally prevented from actuating the Weston clutch by a spring 20, but when a heavy load is raised the spring is uncoiled and the pinion is rotated on the shaft 17 until the Weston clutch is applied. When lifting light loads the spring 20 unscrews the pinion 18, thereby releasing the Weston clutch and the clutch member 25 and permitting the clutch members 22, 21 to engage. When lowering, the ratchet mechanism 11, 12 forces the clutch 24, 25 to slip. As shown in Fig. 1, the low-gear 1, 4 for lifting is connected to the winding-drum 9 by a clutch 6, 10 when a heavy load is suspended from the hook 16, whilst the high gear 2, 7 is connected to the winding-shaft by a ratchet mechanism 11., 12 for lowering rapidly, the clutch then slipping. In a modification shown in Fig. 5, the driven wheels of the gears are mounted on the winding- shaft and the ratchet gear on the driving-shaft, the clutch 4, 34 being applied by the wheel 7, screwed on the shaft 8, when raising the load. When lowering, the wheel 2 is driven by the ratchet mechanism and unscrews the wheel 7. The wheels 7, 33 rotate at different speeds and, owing to the friction of a washer 35 between them, the wheel 32 must be driven to lower the load. If the driving power be removed the load is sustained by the friction. In further modifications the cone clutch 4, 34 is replaced by a Weston clutch and the shaft may then be screwed as before or fitted with cam-surfaces operating on the wheel 7 in a similar manner. The clutch 4, 34 may also be operated by mounting the winding- drum 9 on a screwed shaft, the wheel 7 then being keyed to the shaft. The winding-shaft may also be connected with screw-gear for raising sluices, &c.