Patent GB-538750-A (GB)
Title: Improvements in or relating to measuring gauges
IPC: G01B7/00
Filed: 1940-10-18
Abstract: 538,750. Linear-dimension gauges. SHEFFIELD GAGE CORPORATION. Oct. 18, 1940, No. 15451. Convention date, Oct. 21, 1939. [Class 106 (ii)] Relates to the type in which a block carrying a work-engaging feeler is supported by spring blades from a fixed block to have a small parallel movement thereto limited by stops- and an indicating arm connected to both blocks, and consists in providing a connection between the movable block and the work-feeler which yields when the stops are met. Fixed within the housing 10 is a stationary block 28<SP>1</SP> having lugs forming a gap 37 within which is located a projection 36 on a movable block 31 connected to the block 28<SP>1</SP> top and bottom by parallel leaf springs 32, 33 which allow a straight line relative movement between the blocks limited to the play between the lug 36 and gap 37. A third sliding block 44 has top and bottom projections 45, 46 and is connected to the stationary block 28<SP>1</SP> by top and bottom parallel leaf springs 47, 48. An abutment 51 fast with the projection 45 is held in engagement with a hard point 50 on the movable block 31 by a spring 52 attached to blocks 44 and 31. A spring 56 yielding holds the block 44 in its lower position. In screwed engagement with the projection 46 on block 44 is a holder 11 carrying a work-engaging element 12. A flexible sealing ring 64 is clamped between the element 11 and the casing and serves to keep out cooling fluid used in the working operation. The whole gauging device is carried from the machine by an arm 20 the bifurcated end of which is clamped to a horizontal shaft 19, about the axis of which the casing 10 moves. The other end of arm 20 is secured to a shaft mounted in a bracket 25 on the machine, and a hydraulic device 28 turns the arm 20 in a direction to keep the gauge up to the mesh. An arm 15 slotted to engage a pin 105 in the casing 10 is secured thereto by a screw 104 and carries a locating anvil 18 and an anvil 17 diametrically opposite to the work engaging element 12. Flexible strips 38, 39 are secured at their lower ends to the fixed and movable blocks 28<SP>1</SP>, 31 and at their upper ends are attached to a rigid rod 40. This arm normally lies between pairs of contact strips 70, 72 and 71, 73, of which strips 72, 73 may be adjusted by screws 91, 95 worked from milled heads. Cross pieces 75, 76 carried by the rod 40 engage the outer strips when the rod 40 moves to right or left and breaks an electric circuit normally made between the pairs of strips. Thus when the work is too small or too large a green or red lamp lights up and when of correct size both lamps light up to cause an amber light to be visible through an opalescent glass. In this circuit is also a relay which strips the feed at this stage. When the work is first being gauged it may be of irregular form or roughened so as to cause excessive movement of the element 11. This would not be transmitted to the arm 40 since lost motion provided by the space 55 is sufficient to permit the part 43 to be raised above the position where it brings block 31 against its stop. When the work is reduced in size until the dimension is nearly reached, then the abutment 51 yielding contacts with point 50 and the gauge arm 40 becomes effective. Modifications are described in which the springs act so as to keep the element 42 in engagement with the work and the mechanism adapted for an inside gauge.