GB175967A - Improvements in hole and like gauges - Google Patents

Abstract

175,967. Krupp Akt.-Ges., F. Feb. 25, 1921, [Convention date]. Surface and outline gauges.-Relates to intermal three-point gauges of the kind that are adapted to be set to a given measurement and to show any deviation from this measurement by means of an indicator and consists in rendering the pressure of the gauging-contact independent of the touch of the operator. In the cylindrical body A of the gauge, is mounted a central bolt B having a conical end b<1> against which bear three balls C. each of which in turn bears, under the action of a spring D upon a feeling-bolt E extending at right angles to the bolt B. At the opposite end this bolt bears upon a second bolt F which can move, against the action of a spring K, in a sleeve G so as to actuate the plunger J of an indicator H h<1> carried at the end of the sleeve. This sleeve is movable in the casing A, and in a surrounding sleeve M which is screwed into the casing and may be locked in any position by a lock-nut N. The sleeves have opposing contact surfaces m<1>, g<8>. The gauge is set by introducing it into a calibrating-ring and moving the inner sleeve G in the direction of the arrow x relatively tc the body of the gauge so as to force out the feeling-bolts E until they make contact with the walls of the ring. Further movement causes the bolt F to compress the spring K and actuate the indicator; when this indicates zero the desired pressure is being exerted by the feeling-bolts, thereupon the sleeve G is locked to the body of the gauge. The cuter sleeve M is then unscrewed until the flat surfaces m<1>, g<8> abut, locked in this position by a lock-nut N, and the locking-device for the inner sleeve G removed; this sleeve may then be withdrawn to the position shown. In use the sleeve G is pushed in until the contact surfaces m<1>, g<8> abut; the pointer H then indicates zero if the hole gauged is the correct size, or shows the amount of departure. In a modification the contact surfaces m<1>, g<8> are kept together by a spring so that as the outer sleeve M is screwed into the body of the gauge the inner sleeve G follows it, thus forcing out the feeling-bolts. In this case a lifting-ring is provided on the sleeve M which, when turned through a right-angle, forces the contact surfaces apart and allows the feeling- bolts to recede a little, preventing injury to them when inserting them into a hole. When inserted, the contact surfaces are allowed to abut again and the reading of the indicator taken.'