GB386844A - Method of and means for determining the wearing or wear-resisting qualities of materials - Google Patents

Abstract

386,844. Testing wear-resisting qualities of materials ; testing lubricating efficiency of liquids. HARRINGTON, W. A., 607, Parramatta Road, Leichhardt, near Sydney, Australia. April 25, 1932, No. 11814. [Class 106 (ii).] Wear of solids when tested in rubbing contact is measured by using a test piece, the contacting end of which is formed to a configuration of determined geometrical form which during the test is worn to a progressively increasing readily measurable " flat " or " chord." Mounted on a base 14 is a slide 16 adapted to be moved by a screw 17 and provided with a slot through which passes a spindle 20 carrying a wellbalanced circular face plate 21. The spindle is provided with grooved pulleys 25, 26, of which the pulley 25 is driven by a belt 27 from an electric motor 29 while the pulley 26 drives a speedometer 32. The spindle 20 is preferably driven through a variable speed friction drive (not shown). A ring-shaped test piece 33, formed from the inner wall of an engine cylinder is secured to the face-plate 21 by clamping bolts, the heads of which engage dovetailed grooves in the plate 21. A test piece, for instance of piston-ring material, is adapted to bear on the ring 33. An extension 36 of the slide 16 supports a partly hollow pillar 37 threaded to receive a feed screw 38 by which a carrier 40 may be moved up and down on the pillar without rotation. A circular plate 43 rotatably supported by the carrier has a diametrical V-shaped groove with which is adapted to engage a knife-edge 50 formed on a plate 51 attached to one end of the test beam 49, horns on the plate 51 preventing side movement of the beam relatively to the plate 43. A foldable arm 53 with a forked end 54 may hold the beam relatively to the face plate. The team 49 and measuring instruments are movable with the slide 16. The free end of the beam 49 is fitted with an arcuate element 55 which engages one or both of the feeling plungers of dial gauges 56, 57 from which the extent of the wear upon a test piece or the thickness of a film of lubricant may be taken. A slider 58 carries a loading weight 59 and may be moved over the graduated beam. On one side of the slide 16 is a bracket 61 adapted to carry a pendulum type of instrument 62 for indicating the pull on the cord 64 attached at right angles to the beam when the mechanism is being used to test a lubricant. A forked clamp 66 is secured to the beam near one end, from which depends a pin 67 rounded to engage a depression in a test piece holder 69 which is slotted to receive test pieces 70 clamped in position by set screws 71. The ends of the test pieces 70 are formed in the shape of an arc of a circle of known radius so that the " flat " worn may be measured accurately as by a direct reading microscope. Where necessary factors are known, the apparatus may be equipped with a secondary device to give a direct measure of the wear. A plurality of testing teams may be fitted and a plurality of test pieces of different metals or alloys may be simultaneously tested. For testing lubricants, a testing piece with a flat contact surface of known area is used, the leading edge of which may be formed in different ways. The test piece may be fitted with a thermometer and the plate 21 may be heated electrically.