Month in the Patent Office: A Selection of the More Important Aircraft and Engine Specifications Published Recently

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.