GB1153632A - Gauging Apparatus - Google Patents

Abstract

1,153,632. Gauging apparatus. SECRETARY OF STATE FOR DEFENCE. Aug.4 1966 [Aug. 5, 1965], No.33523/65. Heading G1M. Gauging apparatus comprises an assembly of two or more heads 6 arranged in axial alignment, for gauging the diameter of the bore of an article, each head including three parts 16, 17, 21 arranged to make a three point contact, preferably at substantially equidistant points circumferentially, upon the surface of a bore, two of which 16, 17 are fixed relative to one another and the third 21 is arranged to be movable radially of each head and independently of the other two parts and to be held in contact with the said surface by means 24 which will at the same time hold the other two parts in contact with this surface, means being provided whereby the position of the point of contact of the third part with the surface of the bore, radially with respect to the axis of the bore can be ascertained The gauging heads 6 are mounted on a pillar 7 connected to a movable carriage 4, which slides in the base 1. The contact elements 16, 17 and 21 are mounted in a ring 8, the elements 16, 17 comprising steel grub-screws and the element 21 being a steel ball mounted in a tubular hole 19 with a further steel ball 22. The wedge shaped end 23 Fig.3 (not shown) of a push rod 24 is fitted between the balls, the other end of the rod passing through holes in the ring 8 and base plate 12 to operate a pin 26 which in turn operates a transducer 34, Fig.3.(not shown). The push rod is spring-biased upwards to force the balls apart and hence the ball 21 into contact with the surface of the bore under test. The article under test is positioned by a flange 13 on base plate 12. The gauging heads 6 are positioned on the pillar 7 at a height dependent on the bore portion under test. The carriage is correctly located over the fixed transducers by means of stops 5. A further vertical push rod 39 extends from the top of ring 8 to gauge the depth of the bore portion and operates a further transducer. Means 52 may also be provided to gauge the external diameter.