Gage

Abstract

A gage including two relatively movable structures which carry two gaging elements for contacting a screw thread or other work surface at different locations and which control an indicator producing a display representing a measurement of the thread or other surface. The two structures are mounted for relative movement by a guide rod attached to one of those structures and slidably movable longitudinally within a bushing attached to the other structure, with a spring applying force in opposite directions to the first of these structures and the bushing respectively to urge the gaging elements against the surface being measured. The bushing is shiftable to different positions relative to the structure to which it is attached, to vary the spring force for use with different size parts or under other varying operating conditions. Each of the gaging elements is precisely located relative to the structure to which it is attached by provision of mating accurately dimensioned partial cylindrical surfaces on the gaging elements and carrier structures, in conjunction with the provision of precisely aligned locating passages in the gaging elements and carrier structures for receiving an aligning pin in closely fitting relation to coact with the partial cylindrical surfaces in locating the gaging elements upon assembly of the device. When it is desired that the two gaging elements contact an internal work surface at three spaced locations, one of the gaging elements may carry two spaced work contacting fingers, and the other may carry a single finger which is receivable between the two first mentioned fingers in a retracted condition in which the finger assembly has a reduced overall dimension enabling it to be easily moved axially into and out of the internal surface.