Patent GB-566608-A (GB)
Title: Lapping machine
IPC: B24B37/08
Filed: 1943-07-05
Abstract: 566,608. Lapping. NORTON CO. July 5, 1943, No. 10897. Convention date, July 4, 1942. [Class 60] In a lapping machine for treating flat or cylindrical work, and having opposed flat faced laps having a rotary and planetary movement, the work is supported in cages, two of which are provided, freely rotatable in a table movable automatically to position one cage in the lapping position and the other in a loading position. The machine comprises two laps 11, 12 carried respectively by spindles 13, 15 rotatably and eccentrically mounted in sleeves 14, 15, which are rotatably mounted in the machine base 10. The laps and the sleeves are driven by an electric motor 20, the laps being driven by belt gearing with tensioning means 35 ... 40 and 47 ... 55 and the sleeves being driven through gearing 60 ... 64 and 65 ... 70 ; the drives are taken from a vertical shaft 28 driven by the motor 20, and, as shown, the upper lap 11 rotates in a direction opposite to that of the lower lap 12. The upper lap 11 is movable vertically towards and from the lower lap by means of two fluidpressure cylinders 80, 81 mounted on a frame 82 on the base 10 and having therein pistons connected by rods 85, 86 to a plate 87 engaging rotatably a groove in the sleeve 14. Fluid to and exhaust from the cylinders is controlled by a valve 94 having a stem 95 with pistons 96 ... 98 thereon and movable either by a control lever 111 or by a solenoid 114 ; fluid is supplied from a reservoir 90 by a pump 92 through a pipe 93 and exhaust fluid returns through a pipe 110. Two work cages 115, 116 are provided, each being of disc shape with work-receiving apertures, rotatably mounted in a longitudinally movable table 117 supported by rollers 119-121 engaging in a groove 122 in the front of the base 10 and rollers 119a ... 121a engaging a V-shaped way 123 in the base. As shown in Fig. 1, the cage 115 is in a loading position and the cage 116 in operative position between the laps 11, 12; after completion of lapping, the lap 11 is raised and the table 117 moved to position 117a, thus moving the cage 116 to loading position 116a and the cage 115 to operative position. Movements of the table 117 as described above are effected by fluid pressure, a cylinder 125 being secured to the table and having therein two pistons 128, 129 connected by hollow rods 130, 131 to hollow brackets 132, 133 on the base 10, fluid being supplied to and exhausted from the brackets by pipes 140, 141 connected to a reversing valve 135, which has a stem 136 carrying pistons 137 ... 139 and is moved by solenoids 147, 148. In order to support workpieces 118 when in a cage, plates 150, 153, supported by brackets on the base, are provided, and in order that the work-pieces may slide readily with the cages on to the lap 12, a plate 156 is provided, having an aperture 157 slightly larger in diameter than the lap. The plate is prevented from rotating by a stud 158 riding in a slot in the plate 150, and the plate is moved by the lap by studs 160, 161, &c. provided with rollers 162, 163, &c. engaging the surface 164 of a mounting plate for the lap 12. On the base 10 is mounted a reversing- switch 170 having a plunger 171 positively located in its two positions by a spring plunger 174 and adapted to close a circuit eitner between wires 175, 176 or 177, 178, the plunger 171 being moved axially by dogs 179, 180 adjustably mounted on the table 117. The sleeve 14 is provided with a block 193 carrying screws 194, 195 which operate, at the ends of the vertical movements of the sleeve, limit switches 196, 197 respectively, the switch 196 being connected in series with switch 170 and solenoid 147 and the switch 197 serving, when closed, to set a time delay relay 200 in motion, and through this to operate a switch 201 to start the motor 20 as the upper lap moves into work-engaging position. A relay switch 204 is also connected between the power lines and solenoid 114, the relay 200 being set so that, after a predetermined lapping interval, it closes a circuit to energize solenoid 114 and thus cause lifting of the lap 11 ; before this operation occurs, the relay 200 causes the switch 201 to open to stop the motor 20. When the upper lap reaches its upper limiting position, it closes the switch 196 and energizes solenoid 147, thus causing the table 117 to move to the right until the dog 179 engages a face 184 on the casing of the switch 170, thus stopping the table in position 117a. When the cage 116 has been loaded with new work-pieces, lever 111 is moved downwardly, thus initiating a new lapping operation, and the subsequent operations as described above, the table 117, however, then moving to the left.