GB277517A - An improvement in hardness testing device - Google Patents

Abstract

277,517. Wilson, C. H. Oct. 15, 1926. Testing hardness of materials.-The apparatus comprises a hard painted engaging member and a support for a test specimen together with mechanism for automatically causing relative movement between the support and the engaging member until they engage with a predetermined pressure, and automatic means for stopping this relative movement. Upon a base 10 is mounted a holed menber 11 having for sliding movement without rotation a screw 20, and a vertical frame member having a horizontal part 13 in the end of which is a hole accommodating the engaging member 15 in alinement with the hole in the member 11. The screw 20 carries at the top a support 21 for the specimen 22 and is operated by worm gear 31, 23 from a continuously rotating shaft 28 loose upon which are bevel gears 35, 36 in gear with a drive wheel 27 on a transverse shaft 25 driven from a belt pulley 26 or from a motor. The bevels have clutch teeth adapted to be engaged by clutch teeth on a sliding member 40 feathered on the shaft 28. The member 15 is fitted with a hard indenting point 16 and has bearing upon it a minor load lever 67 carrying a weight 69. A control shaft 47 provided with a spring barrel 48 constantly urging the shaft to rotate counterclockwise carries a crank disk 45 a pin 55 on which in the neutral position of the shaft rests behind a shoulder on a lever 56. In use, the specimen is placed on the table 21 and the lever 56 depressed to release the pin 55 allowing the shaft and disc 45 to rotate until the pin comes against an armature 62 of an electromagnet 80. This movement of the disc 45 through the lever 43 clutches in the gear 35 and the screw 20 is raised, the specimen engaging the member 15 and raising the minor load lever 67 until a contact 75 engages a contact 76, whereupon the circuit of the magnet 80 is closed and the armature 62 moved to release the pin 55 which moves until held by the post 87 of a double pawl 87, 88, the wheel 35 being declutched in this movement and a pin 90 on the disc 45 engaging the cam end 91 of a lever 92 to move a clutch member 103 to cause the gear 101 to be clutched to the vertical shaft 95. This through worm gear 110, 111 and a cam 117 raises the main load lever 114 loaded by a weight 118 and causes the load to be applied to the indenting member through a link 122 and knife-edged lever 120. The hardness number due to penetration is indicated on the dial 70. After a complete rotation of the cam 117 during which the pin 55 passes to the pawl 88, the pin 55 is released and moves to engage the pin 142 on the end of the reversing pawl 141. The clutch 103 is disengaged and the clutch member 40 moved to engage the wheel 36 reversing the drive and lowering the screw 20. An arm 147 ultimately presses down a pin 143 and through link 140 releases the pin from the pawl 142 to perform its last movement, during which the clutch 40 is disengaged, the pin coming to rest against the shoulder 60. The clock spring is wound up once during the revolution by gears 50, 51, shaft 52 and gears 135, 136 from shaft 112. Specification 191,232 is referred to.