Patent GB-633741-A (GB)
Title: Improvements in and relating to contour-gauging apparatus
IPC: G01B7/28
Filed: 1947-06-20
Abstract: 633,741. Surface and outline gauges. FELLOWS GEAR SHAPER CO. June 20, 1947, No. 16394. Convention date, July 20, 1946. [Class 106 (ii)] [Also in Group XXXVIII] In a surface testing machine of the type in which contactors are disposed to bear on a master form and a work-piece, respectively, and to be movable in unison in directions toward and away therefrom, and one of the contactors is movable relatively to the other and means are provided for measuring its relative movements, the supporting means for the contactors are operable to move the contactors in two directions transverse each to the other and both transverse to the directions in which the contactors move toward and away from the master form and work-piece. The machine comprises a base 10 supporting a column 11 housing a vertically adjustable tailstock 12 in which are two spindles 13, 14 vertically adjustable in the tailstock, which co-operate with two spindles 15, 16 in the base to support a master and a work-piece in parallel relationship. Fig. 3 shows only the upper and lower spindles 14, 16 for the workpiece. The lower spindle 16 can be adjusted vertically. Separate contactors 40, 41 (shown diagrammatically in Fig. 11) mounted on a common carriage 43 engage the master M and work-piece W, respectively. The contactor 41 is arranged to actuate a dial gauge 50, and the contactor 40 is fixed. The carriage 43 can be moved in three dimensions. It is slidable towards the specimens, under the action of a weight 57, on a slide 54 vertically adjustable on a saddle 55 which, in turn, is horizontally adjustable on the base 10. The lower spindles 15, 16 are turned while the contactors travel across the master M and work-piece W by means comprising a cam or tangent bar 74, Fig. 11, carried on the saddle 55, adapted, when the saddle is moved horizontally, to move a rack 75 to actuate a sector gear 81 meshing with a pinion 82. The pinion is coupled, through a friction drive, to a coaxial gear 83 meshing with gears 84, 85 on the spindles 15, 16, respectively. The tangent bar 74 can be set so that its reaction surface 77 is inclined at any angle to the path of travel of the saddle 55 to determine the rate and degree of rotation of the spindles 15, 16. The shape of the reaction surface is designed to suit the work-pieces to be tested. To allow relative rotation of the gears 82, 83 when special workpieces are to be tested, the gear 83 is secured to a sleeve on an inner shaft to which the gear 82 is keyed, and the gear 82 is spring-pressed to engage the sleeve to drive it frictionally. A side face of the gear 83 has teeth thereon adapted to be engaged by a pinion on a slidable shaft, whereby the gear 83 can be manually adjusted relatively to the gear 82. Recording apparatus. A permanent record may be made of the variations of the workpiece from conformity with the master form. A lead screw 70, Fig. 11, which is rotated to traverse the saddle 55 and carriage 43 carrying the contactors 40, 41, has a gear 106 thereon meshing with a gear 107 on a flexible shaft 108. A pinion 109 on the shaft meshes with a train of gears 110 (including a reversing gear) adapted to drive a drum 111 over which a strip of record paper 112 passes. A pen or other marker is moved transversely of the paper by an electrical bridge system controlled by movement of the detecting contactor 41. The contactor 41 is mounted on a sub-carriage or holder 47, Fig. 8, engaged by the spring- pressed plunger 49 of the dial gauge 50. This holder carries a stud 113 engaging a magnetic armature 114 suspended by a spring between coils 116, 117, whereby the movements of the contactor 41 change the voltages across the coils, and this, in known manner, operates the pen recorder. The coils and armature are suspended from a ring 121 which can be rotated in a housing 120 to set the axis of the coils and armature at an inclination to the movement of the contactor to alter the magnification of the recording means. The holder 47 actuates the plunger 49 of the gauge 50 through a plate 125. A shiftable stop 126 pivoted on the housing 120 engages the plate 125 to register the housing relatively to the holder 47. In a modification, the holder 47 is suspended by flexible reeds from the housing 120, and the armature 114 is carried by the holder. For testing conical surfaces, the driving means for propelling the paper record strip is correlated with the rotation of the spindles 15, 16 carrying the master and work-piece. Specification 584,737 is referred to.