GB511480A - Apparatus for determining and measuring irregularities in the profile of a surface - Google Patents

Abstract

511,480. Surface gauges. AKTIEBOLAGET C. E. JOHANSSON. Jan. 23, 1939, No. 2335. Convention date, Feb. 2, 1938. [Class 106 (ii)] In a device for gauging irregularities in surfaces in which a needle is movable towards the surface and is associated with a measuring instrument indicating its movements the surface and needle being also capable of lateral relative movement, the needle is raised before any lateral movement takes place. A base 10 supports a screw-threaded standard 11 over which a block 12 may be moved by rotating a nut 13, the block being split and provided with a clamping screw 14 by which it may be secured at the point of adjustment. Two flat springs 17 which support the indicating instrument 18 are secured to the block 12. An arm 19 also attached to the block 12 carries a micrometer screw 20. A very fine needle 24 is carried by the plunger 23 of the instrument 18 which is provided with protecting lugs 26 at either sids of the needle. Between the lugs and embracing the needle is the forked end of an arm 27 normally pressed down by a spring 30 and connected by a thread 31 passing over a pulley. 32 to a lever 33 pivoted to the end of a support 34 secured to the arm 19. In use, the surface 45 or 46 to be examined is placed on the base 40 and the block 12 adjusted by turning the nut 13 until the lugs 26 touch the surface and the block 12 locked by turning, the, screw, 14. The indicator is now. adjusted to a suitable point above the surface by turning the screw 44' which bears against the block 12. The block is slotted at 41 and screws 42. passing through the..outer screw into the part 12a. These are thus pulled out to raise the indicator. The pawl 39 is now used to release the lever 33 which. allows. the spring 30 and arm 27 to release the needle 24 which engages the work. The position opposite 25 is.read and. for the next operation the needle has to be moved laterally A thimble 35 is connected to the spindle 37 by a lost motion device afforded by curved slot 31 and pin 38. On rotating the thimble, it first moves the lever 33 to the dotted line position raising the'needle. Further turning bends the springs 17 and moves the indicator laterally by an amount measured on the screw. The needle is released and a second reading is now taken as before and so. on.