Patent GB-236958-A (GB)
Title: Improvements in or relating to the manufacture of templates for grinding machines
IPC: B24B19/12
Filed: 1925-07-13
Abstract: 236,958. Birkigt, M. July 14, 1924, [Convention date]. Disc apparatus; gauges. - In a machine for grinding profiled articles such as the cam templets used for machining cam shafts of explosion engines of the Hispano-Suiza type, the eccentric portions of the templet are ground by mounting the blank in a swinging arm which is moved past a stationary grinding disc. The templet, Fig. 4, may comprise two cam profiles mounted on the same spindle, each consisting of symmetrical raised portions AB, AB<1>, a cylindrical portion CC<1> and concave portions BC, B<1>C<1>. The templets may be used in the machine described in Specification 236,959 for grinding cam shafts. A frame b carries a lever arm c which is operated by a handle c<2> and is pivoted on an axis c<o> parallel to, and in the same horizontal plane as, the axis a<o> of the grinding-wheel a. The radius. of the grinding-wheel is equal to that of the concave portions to be formed on the work. The blank spindle d is mounted in bearings c<1> and may be locked in any position relatively to the arm c. The blank spindle may be secured to a disc e provided with three graduated scales e' and with series of holes e<o>. Quadrants fare adjustably fixed to the holes in the disc by bolts g and each quadrant carries a spring pin h which normally projects beyond the face of the quadrant. The spring pins coact with a hole h<o> in the arm c to lock the disc and thus also the blank spindle in the required position. In grinding the faces of the raised portion of the cam, the blank is first set so that one face of the projection d<1> is perpendicular to the line joining the axes c<o>, d<o>, this adjustment being facilitated by means of a setting-member j. The grinding is then performed by swinging the arm c<2> towards the grinding-wheel as indicated in Fig. 1. Movement of the arm c in the downward direction is limited by a bolt k adjustable in an arcuate slot in the frame. If necessary, the grinding-wheel is fed forward and the swing- ing movement repeated until the grinding of the face is completed. The spindle d is then unlocked and reset to grind the second face of the projection d<1>. To grind the remaining portions of the cam, the arm c is locked in a horizontal position by a bolt l mounted in an extension of the frame, and the grinding-wheel fed into the stationary work to grind the concave portion BC. The blank is then rotated on its axis to grind the concentric portion of the cam and the second' concave portion B<1>C<1>. A feed movement may then be given to the grinding-wheel and the blank rotated in the reverse direction between the same limits. The top of the raised portion of the cam is finally rounded off in any suitable manner. In order to determine the limits of the axial rotation of the blank spindle, the arm c carries on either side pivoted fingers l which are adjustable in height and which coact with the spring pins h of the quadrants. When one cam has been ground the second cam on the spindle is formed in a similar way, the required angular relation between the cams being obtained by the above-described setting devices. In a modification, the bearings c<1> may be adjustable on the arm c so that the distance between the axes c<o>, d<o> may be varied.