| 摘要 |
1,260,704. Screw-and-nut mechanisms. INTERNATIONAL BUSINESS MACHINES CORP. 23 April, 1969 [22 May, 1968], No. 20758/69. Heading F2Q. Coarse axial adjustment of a probe 1 may be effected by manual rotation of a knob member 8 when it is held in an axially extended position, shown in Fig. 2A, against the action of a spring 41, to cause disengagement of a clutch 7, 39, and fine adjustment may be effected by rotation of the knob member 8 with the clutch 7, 39 engaged. The knob member 8 carries drivepins 10 which engage axial slots 45 in a tubular member 4 which has a relatively coarse screwthreaded engagement with a support member 5. A sleeve 3 is slidably and rotatably mounted within the tubular member 4 and has a relatively fine screw-threaded engagement with the probe I. The sleeve 3 carries at one end a clutch part 39 and a closure cap 6 which is urged by a spring 42 into engagement with a thrust ball-bearing 12 carried by the tubular member 4. The probe 1 is prevented from rotating by a plunger 53 which engages a keyway 51 in the upper surface of probe 1. A pin 13 limits axial movement of the probe 1. When the clutch 7, 39 is engaged the screw threads act differentially. Two such probe mechanisms are used at right angles to accurately position a workpiece such as a semi-conductor wafer.
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