Patent GB-606732-A (GB)
Title: Improvements in or relating to shaft couplings
IPC: F16D11/10
Filed: 1946-01-17
Abstract: 606,732. Looms, driving; levelling healds. SULZER FRERES SOC. ANON. Jan. 17. 1946, Nos. 1633 and 1634. Convention dates, Jan. 20, 1945 and May 19, 1945. [Class 142(i)] [Also in Group XXIV] A positive clutch or detent applicable to looms comprises two or more interengaging claw members which on axial disengagement are maintained apart by the inward movement of a blocking member and are prevented from re-engaging until after a relative rotation of the members into their next position of registration. As shown, the member 17, Fig. 2, is slidably splined on a shaft 5, carries an operating collar 10, and may be spring loaded to engage the member 16, Fig. 1, which, when set up, is'rotatably but not slidably mounted on the shaft 5 and carries a sprocket wheel 2. The pawl 13 is pivoted on the member 16 and is pressed inwards by a spring 14 to engage a cutaway 19 on the member 17 on disengagement. Upon relative rotation, the member 17 passes on to the member 16 before the pawl leaves the cut-away and, owing either to the axial depth of the pawl being greater than the combined depths of the claw and cut-away or to the axial stepping (not shown) of the trailing edge of the member 17, the pawl,'after riding up a chamfered edge 21 on the member 17, does not engage the cut-away at the completion of a revolution and the members 16, 17 are free to re-engage. The cut-away 19 may be dispensed with, the pawl 13 coacting with the front face of the member 17. As applied to a loom mechanism to give reversal through one pick upon breakage of a weft thread, the prime mover 23, Fig. 13, powers the warp beam motion 26, cloth beam motion 27 and heald shaft operating machine 29 through a clutch 4, 1 of this type, and an auxiliary reverse drive 38. 37 brought in by a clutch 36 is provided. The clutches 4, 36 are connected mutually and to an operating lever 30 by a double lever linkwork 32, 33. Upon breakage of a weft thread, the loom and prime mover are stopped in. a known manner and the lever 30 is moved to'the right to disengage the clutch 4 against its spring 9, the blocking member 13 falling inwards to maintain this disengagement so that return of the lever 30 by a spring 34 engages the clutch 36. The loom mechanism is then driven backwards until the member 1 has rotated sufficiently to allow the spring 9 to re-engage the clutch 4 and disengage the clutch 36. To prevent damage due to possible simultaneous connection of both main and auxiliary drives. the clutch 36 is of a type which overruns on excessive torque. To move the heald shafts from the open to the closed shed position and vice versa a positive detent 4, 1 of this type is used, of which one member 1 is fixed and the other member 4 is sidably splined to a hollow shaft 5a mounted, to conserve space on the shaft 39 serving the warp and cloth beam motions. Also slidably splined on the shaft 5a and abutting a fixed collar 45 thereon are a clutch member 46 for an auxiliary drive 38, 37 and a sprocket 42 powering the appropriate chain wheel 44 of the heald shaft operating machine. The members 4, 36 are joined. by a toggle 47, 48 operatively connected to a spring-returned lever 50. With the loom running normally the member 4 is arrested and the clutch 46 open. When the loom is stopped in a known manner e.g. in consequence of a warp thread breaking, the lever 50 is moved downwards and the toggle broken to disengage the member 4 against a spring 9. the blocking member 13 then preventing its re-engagement and causing the engagement of the clutch 46 when the lever 50 is released to straighten the toggle. The wheel 44 is then driven to move the heald shafts to the closed shed position until the member 4 engages to break the drive. A second depression of the lever 50 causes the return of the heald shafts to the open shed position through the same sequence of operations.