Patent GB-110800-A (GB)
Title: Improvements in Grinding Machines.
Inventor: BOOTH CLEMENT
IPC: B23B29/24
Filed: 1916-11-02
Abstract: 110,800. Booth, C., and Page, A. C. Nov. 2, 1916. Disk and wheel apparatus.-Relates to machines for grinding surfaces of revolution and particularly for simultaneously roughing and finishing the surfaces of two different articles while a third is at rest and in position to be removed from the machine. The machine comprises an intermittently rotated circular head 1 supporting workholding spindles 2, 2', 2" each provided with gearing for rotating it, means for throwing out of action the gearing of each spindle in succession as, by the movement of the head, it is brought into the idle position, and a reciprocating carriage 3, supporting the spindles of the roughing-wheel 5 and the finishing-wheel 5<1>, adapted to move the wheels in the axial direction up to the work, then to move them to and fro over the surface of the work, and, finally to draw them back to the starting position. The grinding-wheels are driven by a belt passing over a driving-pulley 69 and a spring-controlled jockey pulley. The carriage is moved to and iro by a rack and pinion driven from the shaft 7 by a change-speed gear, controlled by a handle 18, and a bevel-gear reversing-train, the clutch of which is shifted by a lever on the shaft 30. This shaft carries another lever 31 coupled by a link to a lever 33, the upper end of which stands in the path of a dog 3<11> on the carriage and fits loosely between two lugs on a rod 34. This rod is carried by two levers 35, 36, of which 36 is extended downwards to engage a spring detent 37, which serves to throw over the clutch mechanism. When the carriage has been moved forwards to bring the grinders into contact with the work, and it is required to move it to and fro in short strokes, the reversing-clutch is controlled by the engagement of two dogs 34<11> on the rod 34 with a projection 40' carried on the carriage. After a certain number of the short movements, the projection 40<1> is turned aside; the carriage then continues its outward movement until the dog 3" encounters the lever 33, when the clutch is thrown into its middle position. For the purpose of this control, the projection 40<1> is formed on a lever 40, which carries also a lever 40" adapted to engage a fixed cam 41'. The lever is secured at the lower end of a vertical spindle 39. A spindle 48 and a surrounding sleeve 46" are mounted in the carriage and geared together at one end by a differential gear 47; at the other end the sleeve carries a disk 46 and the spindle a loose pulley 52 and a roller clutch. The clutch is held out of action by the engagement of a projection on the clutch cage with a pivoted dog, which is coupled by a link 43 to a lever 42 at the upper end of the spindle 39 of the lever 40, so that, when the roller passes over the cam, the dog is pulled back, the clutch liberated, and the pulley sets the spindle in rotation. The dog and the connected parts are at once restored to their former position by a spring, and the clutch is again arrested at the end of one revolution. This action is repeated at each stroke of the carriage, the sleeve making a certain angular advance for each rotation of the spindle, until finally a projection on its disk 46 displaces one end of a lever and carries it inwards, turning the spindle 39 and swinging aside the projection 40'. Each grinder is carried on a separate set of transverse slides movabla in the carriage. The upper side of each set is adjustable on the lower by a hand-wheel and screw; the lower slide is pressed in one direction by a spring, but the movement is controlled by a cam on the sleeve 46<11> of the clutch-control gear acting upon one arm of a lever, the other arm of which engages an adjustable stop on the slide. The head 1 is mounted in bearings 74', 74" in the frame 74 and carries a speed-ring 75 driven through a wheel 76 from a wheel 78, which may be clutched to the shaft 80 of the driving-pulley 80<1>. Normally, the clutch mechanism is held inoperative by the engagement of a projection on the clutch cage with a dog 82' fixed on the shaft 82 together with an arm 82<11>, which carries a roller making contact with the outer surface of the head. In the positions of rest, the roller lies in flats or depressions on the head and the clutch dog lies under the projection on the cage. The head is locked in each of its three positions by a pin 85 engaging holes therein. The pin is connected to a cross-shaft 83 provided with a handle 83<1>; it is also engaged by an arm 87' on a spindle 87, another arm on which is linked to a lever on the shaft 82. When the handle is turned, the locking-pin is withdrawn and the dog of the clutch is drawn back to throw in the gear. When the head has turned through one-third of a revolution. the locking-pin engages the next hole and the roller drops into the next depression in the head, whereupon the clutch cage is again arrested. The bolt 85 is locked in engagement with the head during the grinding operation by means of a forked Lever 92, an arm 92" of which bears upon a roller on a lever 91 coupled by a link to a lever on the shaft 83; the lever 92 is thrown over by a projection 3d on the carriage. The work spindles each carry a spur-wheel 104 in gear with a central wheel 103, the shaft 102 of which is driven by chain gearing from a shaft 98 driven by changespeed gearing from the shaft 80. The wheels 104 are coupled to the spindles by roller clutches each provided with a lug adapted to be engaged successively, as the turret is revolved, by a dog 106, so that the spindle to which the work is being applied may remain stationary while the others are rotating.