Patent GB-620379-A (GB)
Title: A towing winch
IPC: B66D1/48
Filed: 1947-01-16
Abstract: 620,379. Towing-winches. JOHNSON, A. A. Jan. 16, 1947, No. 1551. [Class 78 (v)] A towing winch (Fig. 2) comprises a steam engine 8 having a drive shaft 10 rotatable in pay-out and heavein directions and provided with a valve gear lever 18 (Fig. 1); electric brake mechanism 84 associated with the drive shaft to hold the latter against rotation or to release it; a line-drum 60 ; gearing (30, 32, 42, 38, (Fig. 1)) connecting the shaft and the line drum and including' (Fig. 3) planetary system 66 (Fig. 5) and brakedrum 56 ; a brakeband 92 (Fig. 5) engaging the brakedrum, resisting means (springs 126, (Fig. 5)) to resist the pay-out of the brakeband and to restore the band to its heavedin position ; a main engine valve 14 (Fig. 1) and an auxiliary byepassing valve 16 ; a solenoid 17 (Fig. 4) to open the auxiliary valve ; connections (136, 138, 140, 141, 148 (Figs. 7 and 8)) between brakeband and valve gear lever 18 to move the latter and to rotate the engine shaft as the line pays out ; and connection between engine shaft and main valve 14 (Fig. 9) whereby the latter opens as the rope pays out. Drum 60 (Fig. 3). Drive from (and to) the engine shaft is through the gear 38 fixed on shaft 40 to sunpinion 64 and thence to planet pinions 66 journalled on the drum. Internal gear 58 on brake drum 56 has hub 48 which is independently journalled in sideframe 2. Pilot switch 154 (Figs. 5, 8). Operated by brake band 92 working on brake drum 56. The ends of the latter are connected to brackets 98, 96, which are connected together by rod 6, the latter having a thread which carries a gear driven by a worm on the axis of handwheel 110. The latter therefore drives the gear along the thread and adjusts the tension of the band. The band also carries atachments 921 which are connected at pivot 94 on the one hand to yoke 128 of springs 126 and on the other hand, to the casing of tube 136. The latter has caps 139, 137 fixed to its ends, and spring 142 presses between sliding collar 141 and lip 147 of sliding inner tube 145. Movement of the band is therefore transmitted to rod 1381 (which passes freely into tube 136) and, through levers 140, 141, 148, 20, 150, 152, makes or breaks pilot switch 154, the reverse motion being effected by the action of springs 126. This period, during which the brakeband moves and no motion is transmitted to work the valve, is adjusted from handwheel 366 which, through levers 368, 370, 372, moves lever 144 about its axis 162 and thereby displaces crank lever 140, 141 and therefore rod 1381 since the crank lever is pivoted on lever 144. Operation of valve 14. By the engine shaft 10. Also the simultaneous operation of the reclaiming switch by the same shaft. The drive shaft 10 (Fig. 10) has a clutch plate 162 which drives clutch plate 164 which is coupled at 166 to spindle 168 and the drive passes therefrom to spindle 182. From spindle 182 (Fig. 11) the drive passes to spindle 192 through hand operated clutch 198. In Fig. 11 spindle 192 drives a traveller 222 along screw 193 and tips the arm 220 to make the contacts 214 of the reclaiming switch. In Fig. 9 the same spindle 192 simultaneously drives spindle 240 through universal coupling 238, and spindle 240 drives squared shaft 250 through rollers 260 which are fixed on block 242 to the spindle and which work in curved slots 262 cut out of sliding tube 252. The effect of this is that the rollers transmit motion to shaft 250 only when they reach an end of the slot and there is therefore a time lag. The drive is passed on through universal coupling 264 to shaft 266 and so to main valve 14. Stop 273 in the fixed housing is threaded and when the shaft rotates the stop slides until it meets stop 269 and thus prevents further rotation when the valve has been opened. Operation of winch (Fig. 4). Imagine,that the winch is disposed in the stern of a ship. and the line is towing a second ship and that there is a sudden extra stress in the line which drags out the line and rotates the drum. The engine shaft and its drive as far as the sun pinion 64 is held fast. Hence the brake band is dragged and its movement is transmitted to make the contacts 316 of pilot switch 154. This, through operation of relay 306 energises brake solenoid 88 which frees the engine shaft, which commences to move. This movement (i) makes contacts 214 of the reclaiming switch (ii) after a time lag opens main valve 14 to drive the engine shaft to let out the line. When the extra stress subsides the brakeband moves back under its restoring springs and limit switch 154 is moved so as to break contacts 316 and make contacts 318 and at the same time valve gear lever 20 moves to the heave-in position..This has the effect (i) through the reversal of engine shaft to close main valve 14 (ii) through contacts 318 to energise solenoid 17 and open auxiliary valve 16 (iii) to wind in the rope. The winding-in is therefore done partly with the main valve and then with the auxiliary valve until the traveller 222 breaks the reclaiming switch contacts and the solenoid 17 of auxiliary valve 16 is switched out, and the apparatus has returned to its original condition.