Month in the Patent Office

Abstract

An aircraft or other propeller shaft driven from two or more motors has means for disconnecting and connecting any motor at will, a delay‐action device being incorporated whereby the change over is completed automatically when there is no load transmitted between the motor and the propeller shaft. Fig. 1 shows a propeller shaft S driven through bevel gear from two motor shafts M1, M2 through two dog‐clutches 4, 5. The ends of the teeth on the clutch members 4, 5 are bevelled in such a direction that engagement is prevented until the motor shaft speed has become equal to the speed of the member 5. Each member 4 is mounted on a shaft 41 capable of sliding through a member 9 driven from the motor shaft through clastic discs 11, teeth 10 preventing overload of the discs by limiting the amount of relative rotation. The shaft 41 is connected by a bearing 14 to a member 15 having a quick‐threaded screw 17 engaged by a nut 18 provided with an actuating lever 19. The upper end of this lever is engaged by a slotted member containing a spring which becomes compressed if the nut is unable to move the member 15. A toothed disc 12 on the other end of the shaft 41 occupies the position shown to the left of Fig. 1 when the clutch 4, 5 is engaged and owing to relative displacement of the motor shaft and part 9 under torque is unable to pass through a toothed ring 13 on the motor shaft. As soon as the torque becomes zero the member 12 can pass through the ring 13 and the clutch member 4, 5 can be disengaged.