Patent GB-553594-A (GB)
Title: Improvements in or relating to the formation of a profile on an article in a lathe, milling machine or similar machine
Filed: 1942-03-11
Abstract: 553,594. Lathes; milling or grinding machines. BRAYSHAW FURNACES & TOOLS, Ltd., BRAYSHAW, S. N., NEWMAN, F. C., and FURBER, F. A. March 11, 1942, No. 3188. [Class 83 (iii)] [Also in Group XXIII] In cutting profiled work on a lathe milling machine &c. an enlarged drawing of the required profile is formed on a screen, the said drawing coacting with a " follower " constituted by a similarly enlarged image of a gauge member having the same outline as the operative edge of the tool, the tool and gauge being mounted to move in unison on compound slides which are operated so as to move the " follower " on the screen around the drawing thus producing the required profile on the work. In the application to a relieving lathe the tool B is mounted in a post b carried by a slide C controlled by a relieving cam c. The cam spindle c<SP>1</SP> is mounted in a slide d to which transverse profiling movement, independent of the relieving motion, may be imparted by a hand wheel d and screw D<SP>1</SP>. The slide D is mounted on a saddle E moved longitudinally by a hand-wheel e and screw E<SP>1</SP>. The gauge, consisting of a replica of the tool point, is carried on a ground glass screen f in a holder F carried on compound hand-adjusted slides F2, F3, mounted on the slide D, the slides F<SP>2</SP>, F<SP>3</SP>, being used to adjust the gauge before the operation. A lamp k in a housing G projects an image F4 of the gauge by reflectors j, on to a screen J<SP>1</SP> carrying the enlarged drawing J, the scale of enlargement of the gauge being the same as that of the drawing. The lamp housing, reflectors and screen may be either stationary as shown or be carried on the slide D. For setting the tool a microscope H is mounted on a support consisting of a bar h<SP>1</SP> slidable on a bar h<SP>2</SP> adjustably pivoted to a plate h<SP>3</SP> temporarily located by pegs on the slide F<SP>2</SP> engaging holes in plate h<SP>3</SP>. After setting the tool the microscope and its bracket are removed. The cam spindle c<SP>1</SP> is driven from the wheel K of a branch train from the main drive through a shaft L, spiral gears l<SP>1</SP>, shaft L<SP>1</SP> and spiral gears l<SP>2</SP>. When the tool rest is angularly adjusted to give side relief the phase of the relieving cam also requires adjustment and this is effected by angular adjustment of wheel K around a disc K<SP>2</SP> on the shaft k, the adjustment being indicated by a scale, Fig. 13. When relieving is effected by a grinding wheel rotating on a vertical axis, the wheel diameter is gradually reduced by the dressing operation and to compensate for this the gauge may be in the form of an adjustable iris diaphragm or may be formed from a strip, Fig. 6, or disc, not shown, having a number of apertures of decreasing size any required aperture being brought into position by means of a locating pin f<SP>6</SP>. In order to avoid altering the size of the gauge, a grinding wheel m, Fig. 9, is employed; this wheel is dressed on its conical face only so that its effective diameter remains constant and the only readjustment of the wheel required is one along the wheel axis. In a modification, Fig. 10; a wheel M<SP>1</SP> on a slide P<SP>1</SP> is trimmed by a tool N on a second slide P<SP>2</SP> operated by a common screw shaft the part p<SP>2</SP> operating slide P<SP>2</SP> being double the pitch of the part p<SP>1</SP> operating slide P<SP>1</SP>.