Patent GB-120611-A (GB)
Title: Improvements in and relating to Clutch Couplings for the Transmission of Power by Shafting.
Inventor: ALEXANDER FRANCIS HERBERT
IPC: F16D11/00
Filed: 1917-11-12
Abstract: 120,611. Alexander, F. H. Nov. 12, 1917. Clutches.-In positive clutches, a pin carried by one clutch part is brought into a groove in the other clutch part in such a position that air or other elastic fluid is confined between the pin and the end of the groove and ensures gradual takeup of the drive until the pin reaches the end of the groove. A pin 4, Fig. 3, carried on a slide 5 is normally held at the inner end of a slot 7 in one clutch member by a spring-controlled lever 8, and is brought by axial movement of one of the clutch members into engagement with the inner end of a spiral groove 3 in the second clutch member and moves along to the outer end of the groove against the pressure of the air in the groove, which air gradually escapes by leakage or through a valve provided at or near the end of the groove. The lever 8 presses the pin into a notch 14 at the end of the groove so that rotation in both directions can be transmitted. The pin 4 may be adjusted to enter the middle of the groove, from whence it may move to either end of the groove, or the lever 8 may be omitted and the pin be manually adjusted to engage either end of the groove. In the form shown in Fig. 6, the pin 4 is arranged, by adjustment of the clutch member F and by sliding a. clutch-operating collar 15, to engage with either end of a helical groove 3 in the periphery of the member F. A relief valve 12 is arranged at each end of the groove 3. In order to prevent the pin 4 from being operated except when the member F is suitably placed, the lever 28, Fig. 9, operating the collar 15 is provided with a pair of lugs 27, one or other of which is adapted to be engaged and locked by lugs 26 on a lever 24, oscillated by movement of the clutch member F, except when a second lever 81, the position of which is determined by the direction of rotation of the driving-shaft and which has a screwed head 32 engaging a screwed sleeve 33 on the lever 24, is in alinement with the lever 24, in which position the lugs 26 pass between the lugs 27, and the member F is suitably placed. The inner member F, Fig. 8, may be manually adjusted to bring either of two helical grooves provided with central end stops 3<11> into engagement with one of two stops 4 fixed on the outer member M, this form requiring opposite relative rotations, of the clutch parts to produce disengagement. The groove may be arranged to form a circle on the drum member, the middle part of groove being bent laterally so that the pin can enter the groove only at that point, or the groove may be arranged as shown in Fig. 13, when the pin 4 can enter the inclined section 36 only. By an arrangement of manually-operated valves and non-return valves, compressed air or other elastic fluid may be supplied to the groove. To prevent loss of pressure in the groove, piston rings 38, Fig. 14, connected by passages 40 with the groove 3 or a pin 4, Fig. 26, with its end formed in spring- separate segments 57, 58 may be provided. Centrifugal devices so arranged as to balance the centrifugal action of the pin 14 may be used. In tho fluid-actuated clutch shown in Fig. 29, the pin 4 in the part M co-operates with a circular groove 3 formed with two stop ends 3<11> , and is operated by a piston 65 in a cylinder 66 supplied with compressed air alternatively above the piston by means of a pipe 71 connected to a manuallyoperated distributing-valve (not shown) or below the piston by a pipe 80 connected to a timing- cylinder 67 connected also to the main distributing-valve by a pipe 72. The connexion between the pipes 72, 80 is controlled by a piston with a rod 78 carrying a roller 77 adapted to engage a cam-plate 76 on the member F. The pin 4, when withdrawn, is engaged by a spring catch 84 formed on a piston in a cylinder 83 connected by a pipe 82 to the pipe 80. When the main valve is operated to supply pressure to the pipe 72, the roller 77 on striking the cam 76 operates the piston-rod 78 to connect the pipes 72, 80 and supply pressure both to withdraw the spring catch 84 and to extrude the pin 4. Compressed air may be supplied also to the groove 3 through a pipe 81 and non-return valve 46. The pin 4 is withdrawn by adjusting the main valve to supply pressure to the pipe 71 and connect the pipe 72 with the exhaust.