GB932474A - Improvements in or relating to telescopic shafts - Google Patents

Abstract

932,474. Telescopic shafts; securing together rotary parts; machinery breaking pieces. D.B.A. Nov. 24, 1959 [Nov. 24, 1958], No. 39782/59. Classes 80 (2) and 80 (4). In a removable telescopic cardan shaft for accessory or accessory gear-box drives on aircraft, wherein intersplined outer and inner shaft sections 1, 4 are respectively splined to input and output (or vice versa) universal joint inner members 3, 8 the shaft is axially located by plungers 21 sliding in radial apertures in the section 4 and engaging a corresponding recess or recesses 22 in the splines of the output (or input) joint inner member 8, the plungers being controlled by means responsive to the relative axial positions of the sections 1, 4 so that when the shaft is in the extended position, for drive, the plungers are expanded into their locating position and when the shaft is telescopically contracted, for removal, the plungers are released for withdrawal. The shaft sections 1, 4 are urged towards their extended position, which is limited by a circlip 13, by a spring 9 acting on the section 4 through a collar 10 and against an abutment on a sleeve 11 axially fixed in the section 1. The means controlling the plungers comprises a conical member 23 screwed on the end of a rod 24 which is leftwardly moved, in the extended shaft position, by section 1 acting through a wall 11a of the sleeve 11, a spring 25 and a washer 26 on the rod to resiliently expand the plungers and block their withdrawal, and rightwardly moved in the telescopically contracted shaft position, by the section 1 acting through the abutment of the wall 11a and a collar 27 on the rod to positively release the plungers. The outer ends of the plungers 21 and the recesses 22 having sloping faces so that withdrawal of the telescopically contracted shaft from the inner member 8 urges the plungers radially inwards. A pin 28 limits the rightward movement of the rod thereby preventing the plungers from falling inside the section 4, and each plunger has a small inwardly retaining flange 21a. The sections 1, 4 are retained in the extended and telescopically contracted positions by a removable stud 14 secured to the free end of a resilient strip 15 secured to the section 1, which stud engages respectively apertures 17, 20 in the section 4, a slidable and rotatable bayonet safety ring 18 having a notch 19 which accepts the stud head being provided for maintaining the stud in the apertures. As shown, a " break " section A is provided in the section 1 adjacent the spline connection with the input joint inner member 3 so that in the event of breakage the shaft stops rotating, remains centred by the sleeve 11, and is axially retained by the plungers