Patent GB-588350-A (GB)
Title: Improvements in or relating to linear dimension gauges
IPC: G01B5/02
Filed: 1945-02-13
Abstract: 588,350. Linear-dimension gauges. KAPELLA, Ltd., and COOKE, E. A. Feb. 13, 1945, No. 3584. [Class 106 (ii)] The linear-dimension gauge described in Specification 567,401 is modified in that the two control elements of the electromagnetic control device are selectively actuated respectively in accordance with the two directions of relativE movement of the two gauging elements, one control element being held against movement during actuation of the other control element. Internal and external gauging can be effected without transposing the gauging elements. As shown, the control device, which is constructed and operates an'indicating or recording instrument as described in Specification 541,627 or 556,607, [both in Group XXXVIII], comprises an outer casing. L containing two balanced coils L<1>, L<2>, a biassing spring and an armature L<3>, attached by spring ligaments N<2> to a subsidiary supporting bar D<2>. Also mounted on the bar D<2> by means of spring ligaments N<5> are two rocking levers, N<6>, N<7> with upper stops N<8> contacting abutments C<5> on the main supporting bar C<2>, The lower ends of levers N<6>, N<7> contact stops L<6> on the bar D<2>, and tappet rods L<9>, L<8> respectively, the rod L<8> acting on the armature L' and the rod L<9> making rolling contact with a recess in the end wall of the casing L. One gauge finger C is normally fixed to, but can be initially adjusted along a slot in, the main bar C2 which is supported at each end by spring ligaments C<4> to a vertically adjustable bracket K ; the other gauge finger D is secured on a platform D<5> on the subsidiary bar D<2> by means of an L-shaped bracket D<6> which is secured to a vertical and two horizontal spring ligaments D<8>, D<7>, respectively, secured to the platform, whereby the finger can be tilted for adjustment about the axis of intersection of the ligaments. The bar D<2> is supported from the main bar C' by spring ligaments D<4> so that it can move parallel to its length relatively to the bar C<2>. The bracket D<6> of the finger D has an extension D' lying between a spring plunger M<2> on the bar D<2> and a stud M<3> on a lever M<4> (not shown). The lever M<4> is adapted to be tilted about a spring ligament on the bar D<2> to tilt and adjust the finger D by means of an adjusting-screw operated by a spindle M<10> (not shown) which is mounted on the bracket K, but has free sliding engagement with the screw so as not to interfere with the free longitudinal movement of the bar D<2>. For external gauging, the finger C is positioned so that a master gauge when inserted between C, D will move C to the right so that lever N<7> compresses the spring in device L. The spindle M<10> is rotated to adjust finger D and zeroize the indicator. A work-piece is then inserted and the indicator automatically registers deviation from standard. For internal gauging, the same-procedure is adopted except that finger C will be moved to the left by the gauge or work-piece thus turning lever N<6> to compress the spring in the device L. The fingers C, D can be adjusted vertically relatively to the work-table &c. to gauge at different heights. The whole of the mechanism shown in Fig. 15 is suspended from the bracket K on a carriage which is mounted inside a casing B (not shown) and vertically adjustable therein, the fingers C, D projecting through a slot in the top of the casing. A flexible steel wire attached to the carriage and passing around a system of pulleys has attached thereto a.scale, comprising an engraved glass strip in a metal frame, guided by rollers to move beneath an aperture in the top of the casing. A glass cover provided with a datum line or pointer, covers the aperture, whereby an indication of the vertical position of the carriage is obtained. The scale is illuminated by an electric lamp which is arranged to be extinguished if the main bar C<2> is swung too far from a central position for accurate gauging. The housing B is supported removably on a pedestal A (not shown) provided with adjustable feet and a retractable ' castoring-device which enables ready transportation of the gauging-apparatus as a whole. Specification 570,493 also isreferred to.