GB376674A - Actuating mechanism for profile grinders - Google Patents

Abstract

376,674. Headstocks for profile grinding. ROSS, C. H. A. F. L., 1619, Massachusetts Avenue Northwest, Washington, U.S.A. Feb. 15, 1932, No. 4489. Convention date, Feb. 21, 1931. [Class 60.] Helical surfaces, grinding and treating ; spindles and spindle mountings.-A profilegrinding machine comprises headstock mechanism consisting of a longitudinally sliding ram actuated by fluid pressure and connected to the work-spindle, the thrust on the ram being arranged to cause predetermined amounts of longitudinal and rotary movements of the work-spindle. The headstock 1, which may co-operate with a tailstock (not shown), is provided with a slideway 4 for a saddle 10, an adjustable gib being provided at 5. The saddle is adjusted by means of a screw 16 actuated by a handle 19 coacting with a graduated dial 20. After adjustment the saddle is clamped by a handle 25 coacting with a locking-member 22. A slide 26 is mounted on the saddle and moves between adjustable gibs 29 retained by plates 27. A frame consisting of parallel rods 32 and cross-bar 33 is secured to the saddle and is also connected to a cylinder 34 supported on an extension 33<1> of the headstock. The piston-rod 36 of this cylinder is bolted to a yoke 37<1> having a boss 51 connected to the work-spindle 42 which is carried in bearings, Fig. 7, in the slide 26. The boss 51 is fitted with a collar 52 having a helical slot 54 coacting with a roller secured to the work-spindle 42. Thus movement of the piston will tend both to rotate the workspindle and also to move the slide 26 and workspindle longitudinally and by suitably choosing the helix angle of the slot 54 the force from the piston-rod gives equal components of thrust and torque on the work-spindle. The cylinder 34, which is preferably hydraulic, is controlled by a four-way valve 100 to reciprocate the piston 35, the valve having an intermediate neutral position, Fig. 15, in which the piston remains stationary. The spindle 42 is hollow and its bore is tapered at the forward end to receive a collet which may be actuated by a draw-bar to grip the work arbor 48. In order to obtain exact control of the longitudinal and rotary movements of the work, a hood 59 is secured to the saddle and is slotted at 63. A templet 64, secured so that its edge extends over the slot, co-operates with a follower arm 66, keyed to the work-spindle. The upper part of the follower is forked at 68, the forks being connected by a cross-piece 69. Rods 70 pivoted on pins 71 are fitted with rollers 73 which are adjusted by wedge devices to contact with a templet. A second templet may be positioned on the opposite side of the slot 63 for finishing the reverse side of a blank, such as a screw propeller carried by the workspindle. In order to balance the weight of the follower arm the spindle carries a wheel 80 fitted with an adjustable balance weight. To maintain the follower roller in contact with the templet, a torque is placed on the workspindle by a weight 84 suspended from a rim of the wheel 80. The outer end of the work, such as a screw propeller, may be supported by a tailstock and a cutting or grinding tool for finishing the work may be fed between successive strokes of the piston. The cutting or grinding may be effected on both forward and return movements of the work, since the follower roller is always kept against the templet by the weight 84. The opening of the control valve may be limited by screws 112 to determine the speed of operation, and after each stroke the valve may be automatically shut by means of dogs on the slide 26. A master plate 87 is set to a definite helix angle and from this the templet may be set to any desired helix angle by means of suitable gauges or spacers. For finishing the reverse side of the work with a second templet the counterweight is moved to the opposite side of the spindle axis.