Patent GB-699966-A (GB)
Title: Grinding machine
IPC: B24B47/06
Filed: 1950-12-14
Abstract: 699,966. Grinding machines. FOUQUET, E. Dec. 14, 1950, No. 30578/50. Class 60. A grinding machine comprises an abrasive wheel 70, Fig. 1, reciprocable transversely to its axis by a hydraulically - operated slide 14 mounted on the machine framework, a work table 6 resiliently supported on a slidable bracket 37, an adjustable stop 48, Fig. 2, to arrest the table independently of the bracket, a dressing wheel 103, Fig. 4, movable towards the abrasive wheel, means for reducing the speed of the latter during a dressing operation, and means for supplying coolant to the abrasive wheel. The slide 14 is made of a light alloy for high-speed reciprocation and is connected to a hydraulic piston 9. The grinding wheel 70 is rotatably mounted on this slide and is driven by belts 87, 93 from a motor 72 pivotally connected at 73 to the machine framework, the weight of the motor being supported by a spring 77. During reciprocation of the slide 14 the motor oscillates about its pivot and the belt 87 is maintained taut by an adjustable strut connecting the motor pulley with a pulley 88 on the slide. Fluid is supplied to the grinding wheel by pipes 18, 19 and nozzles 21, 22 pivotally adjustable on the grinding wheel housing. This fluid and the particles of solid matter resulting from either a grinding or dressing operation are directed by channels 5, 26 and 28 to an inclined surface 2 which communicates with an outlet 3 at the rear of the machine. The work 99 is mounted on a table 6 slidably connected with a bracket 37 which is in turn slidably mounted on the framework of the machine. Springs 41 are interposed between the table and the bracket. The upper limit of travel of the table is determined by an adjustable screw stop 48 carried by a slide 51 which may be adjusted with respect to the frame of the machine by a screw 53 provided with a scale 58. The bracket 37 carries two adjustable . stops 59, 61 to co-operate with two switches 63, 64 mounted on a fixed abutment 65. When setting up the machine the bracket 37 is lifted by a hydraulic jack 68 until the work comes into contact with the grinding wheel whereupon the screw stop 48 and the stop 59 are separated from the table 6 and the switch 63 respectively by an amount equal to the required depth of cut. Actuation of the switch 63 produces a reversal in the flow of fluid to the jack while actuation of the switch 64 brings the jack to rest. The wheel 70 is dressed before each operation by a dressing wheel 104, Fig. 6, which is mounted eccentrically on a pin 111 carried by a slide 105 in engagement with an adjusting screw 106 having a scale 109. The pin 111 may be rotated through 180 degrees by a crank 115 and an indexing detent 116 to bring the wheel 104 into or out of contact with the grinding wheel. This arrangement renders it unnecessary to reverse the screw 106, and errors in the reading of scale 109 are thereby avoided. The variation in the reading of this scale between successive dressing operations provides a direct indication of the reduction in diameter of the grinding wheel and the screw 53 is adjusted to compensate for this. If desired, the screws 53 and 106 may be mechanically coupled. To obtain the reduced speed of the wheel 70 necessary for dressing, a low speed motor is connected to the shaft of the motor 72 by a ratchet drive embodying spring-loaded pawls which are flung out of engagement with the ratchet wheel by centrifugal force when the motor 72 is running. Specifications 578,653 and 699,965 are referred to.