Patent GB-232296-A (GB)
Title: Improvements in clutches and brakes
IPC: F16D43/02
Filed: 1924-01-07
Abstract: 232,296. Woodhouse, A. E. Jan. 7, 1924. Clutches, friction; controlling clutches.- Friction clutches are engaged or disengaged by centrifugal force acting on the clutch members themselves or parts associated therewith, the centrifugal force being opposed by the contracting-action of a cord, chain, band, or Bowden or other wire encircling the centrifugallyexpanded members and, in general, subject to tension by manual, spring, weight, steam, or electromagnetic forces. Wholly-automatic forms are described in which clutching occurs when centrifugal force overcomes spring or weight tension in the cord &c., the action sometimes being delayed by adjustable trip-pawls or dashpots or both. The controlling-means may rotate with the clutch or be wholly or partly stationary. In non-automatic forms, a stationary cord &c. is tensioned at will by manual or power means to overcome the centrifugal engaging or disengaging force. Specification 183,460 is referred to. As applied to an automatic coil clutch c, Fig. 1, for coupling shafts g, b the ends of the coil project through openings x in a split centrifugal sleeve b, b<1> and are adjustably secured to the controlling- cord a. Expansion of the sleeve b, b<1> tightens the coil c, against its own resilience and, if desired that of auxiliary springs, so that it grips sleeves e, e<1> on the shafts g, h. The driving-sleeve e imparts rotation to the sleeve b, b<1> by a pin i. An oil-tight casing k and lubricating-holes in the sleeve b, b' may be provided. As shown in Fig. 3, the cord a may be duplicated at each end of the clutch and a band d, anchored at one end l to a stationary casing m and secured at the other end to a lever n, encircles the middle of the divided sleeve b, b<1>. Normally the band d is arranged to produce no lateral thrust, but its end l may be so disposed as to produce a resultant pull counteracting weight or belt-pull on the shafts. The lower end of the lever n is detained by a roller on a tiltable pawl p, which can be set by a screw w at varying angles to adjust the speed at which it trips. The lever may also be connected by a cord s to an adjustable dashpot r to cause slow clutching-action. The apparatus is automatically reset by a spring t. This clutch is stated to be applicable for starting loads driven by internalcombustion engines and squirrel-cage motors. The pawl p may be dispensed with and the lever n extended upwards for manual control. The band d may be arranged for operation at either end or may be prolonged for remote control. The band may rotate with the clutch and be connected to an end plate having rotative movement under the control of a trip and dashpot or dashpots. In another form, a staionary band contracts a normally stationary split sleeve on to the coil ends to cause it to grip, the resilience of the coil and centrifugal force releasing the sleeve when the band is slackened. One Provisional Specification describes the controlling-cord &c. as passing over sheaves and as encircling the controlled parts more than once; also several dashpots may be used in series or parallel; hydraulic or pneumatic means may be used to operate the cord &c. ; the cord &c. may similarly control spring-actuated non-centrifugal clutches; and clutches may be disengaged centrifugally against a spring-tensioned cord &c.