GB936209A - Improvements in or relating to micrometers - Google Patents

Abstract

936,209. Micrometers. MAUSER-MESSZEUG G.m.b.H. May 12, 1960 [June 11, 1959], No. 16831/60. Class 106 (2). In a micrometer the measuring spindle 10 is constrained to slide and not rotate by a groove 12 engaged by a screw 13. The spindle 10 is internally threaded at one end and is engaged by a screw spindle 14 which can be turned by a ratchet mechanism 23. The spindle 14 is supported by two ball bearings 32 designed to take up end-thrust. The bearings are held in place axially by a ring nut 35 secured to the outer sleeve 30 of the micrometer and a shoulder 33 formed thereon, and the bearings also abut a collar 18 formed on the spindle 14 and a nut 34 secured to it, thus preventing axial movement of the spindle 14 when it is rotated by the ratchet 23. The usual vernier reading is given by a vernier 73 and a scale 72 secured to the sleeve 30 and a second sleeve 39 respectively, the second sleeve being fixed to rotate with the shaft 14. A driving wheel 66 is carried on the collar 18 and meshes with a pinion 65 keyed on a shaft which also carries a second pinion 64 in mesh with teeth formed on the rim 63 of a wheel 62. This wheel carries on its periphery the number ring for hundredths and operates, by means not shown, pinions 56, 57, 58 which are the tens transfer gears and mesh with internal teeth on counter wheels 59, 60, 61, which indicate the tens, integers and tenths of the measurement respectively. A device for locking the measuring spindle 10 consists of a split ring 83 mounted between chamfered rings 82, 84 slidable on a member connected to the sleeve 30. If the ring 82 is pushed towards the ring 84 which is held axially by a spring ring 85, the split ring 83 expands and locks the scale-carrying sleeve 39 in place. A knurled ring 80 screws on to the housing 11 and when screwed down it forces three rods 81<SP>11</SP> (only one shown) against the ring 82, thus locking the micrometer in its adjusted position.