Patent GB-716779-A (GB)
Abstract: 716,779. Gyroscopic apparatus., MINNEAPOLIS-HONEYWELL REGULATOR CO. Dec. 31, 1952 [Jan. 2, 1952], No. 33079/52. Class 97(3) A gyroscope has a rotor mounted in a pair of gimbals for displacement about two mutually perpendicular axes and includes a centring and caging apparatus for centring and locking the rotor with respect to one of the axes while simultaneously applying a brake to hold the rotor with respect to the other axis, thereby destroying the spatial rigidity of the gyrcscope at the exact initiation of the centring operation, and thereafter freeing the rotor with respect to said other axis and centring and locking it with respect thereto. The caging apparatus of the gyroscope shown comprises a rotary solenoid motor 30 for actuating a plate 35 having a cam surface 36 contacting a pivoted .member 37 connected at 51. to a member 50 slidable in a guide 52. When the motor 30 is deenergized. the cam plate 36 is rotated in one direction by a spring 59 and the pivoted member 37 is rotated by a spring 45 so that the member 50 is moved in the guide into contact with a cam 60 pivoted at 68 to a bracket 65 on an outer gimbal 13. Consequently the cam is rotated slightly about its pivot 68 and a part thereof pivots an arm to move a geared shoe 99 against spring action 92 into mesh with a gear 98 on inner gimbal 11 to lock the inner gimbal. When the brake has been applied, the cam 60 cannot pivot further so that further pressure on the cam 60 causes rotation of the cam 60 and of outer gimbal 13 about the axis of this gimbal until the member 50 engages a slot 70 in the cam and thus locks the cam and outer gimbal 13 in centred position. Since there is now no pressure on cam 60, it is allowed to pivot back to its central position so that brake 90 and therefore gimbal 11 is released. Simultaneously, the member 50 engages a forked member 100 on gimbal 13 to positively lock it. Further movement of member 50 results in contact thereof with a spring loaded member 101. a part 107 of which is pressed against a cam 62 on the inner gimbal 11. This cam and therefore the gimbal is rotated until the part 107 faces into a slot 112 in the cam to lock this gimbal in centred position. When motor 30 is energized, the cam plate causes member 37 to pivot and move member 50 in reverse direction whereupon the gyro becomes uncaged. In the form shown in Fig. 5, the brake 90 for the inner gimbal 200 is actuated by a cam 220 resiliently mounted at 224 on the outer gimbal 203 and adapted to be engaged by a pivoted cam follower 241 operated by a cam 240 on a shaft 231 having a spring 233 at one end, and, at the other end, geared to a motor 30. This shaft also carries a member 246 for actuating with lost motion on cam 245, loosely mounted on the shaft, which pivots a follower 250 into engagement with a spring loaded pin 212 for centring and locking the cam 62 on the inner gimbal, this gimbal being centered and clocked after cam 240 has caused the cam 220 to centre and lock the outer gimbal 203. In this embodiment. motor 30 is energized, to cage the gyro which uncaging is accomplished by spring 233. Shaft 231 also carries with lost motion a cam 260 for operating one part 265 of a lock for the outer gimbal. this part 265 co-operating with. part 230 on the outer gimbal.