Patent GB-613108-A (GB)
Title: Improvements in or relating to grinding machines
IPC: B24B3/04
Filed: 1945-02-23
Abstract: 613,108. Grinding and polishing. HJELMBLAD, K. W. J. Feb. 23, 1945, No. 4643. Convention date, March 4, 1944. [Class 60] In a grinding machine having an adjustable guide rail, curve or the like co-operating with transmission means for imparting the appropriate rotational movement to a spindle and a work-piece carried by said spindle during relative traverse of the work and grinding wheel, the transmission comprises a member engaging said guide rail and adjustable to an initial position coaxial with a centre about which said guide rail is rotatable for its adjustment and the adaption to the shape of the tooth or edge of the work, a dividing plate or the like positively connected with said transmission means having a locking hole or other locking means for engagement with a latch or other locking member mounted in a dividing head to lock the dividing plate and transmission in said initial position, means also being provided to indicate the location of a certain point on the edge to be ground when the transmission means and the guide rail take said initial position, and the location of a further point on the same edge after the guide rail has been adjusted from said initial position, by way of the work and the transmission, to a position corresponding to the inclination or shape of the edge to be ground. A rotary grinding disc 3 is carried by a standard 2 adjustable for height on machine frame 1, which frame also carries a slide 4 adjustable towards and away from the grinding disc and supporting a table 5 adjustable transversely of the slide 4. On the table 5 is a plate 6 rotatably supporting an angular piece 7 having rotatably secured thereto a dividing head 8 carrying a hollow spindle 9 on to which a tool 10 may be clamped by means of a rod 12 extending through the central hole 11 of spindle 9. A gear-wheel 13 is freely rotatable on the spindle 9, its hub 14 having a flange 15 to which is exchangeably secured a dividing plate 16 with dividing apertures 17<SP>1</SP>, 17<SP>2</SP>, 17<SP>3</SP> ... and a locking aperture 18 adapted to receive a latch 19 arranged on the dividing head 8 when the dividing plate is in its zero position. A carrier disc 21 with graduations 20 is freely rotatable on the spindle 9 to which it can be locked by a handle 22; the disc has a stop-pin 23 engageable with the dividing apertures 17. The dividing head 8 has a handle 24 for locking the spindle 9 to the head. The gear-wheel 13 engages a rack 25 vertically displaceable in the dividing head 8 and having at its lower end a roller 26 engaging a guide slot 27 in a guide bar 28 displaceably mounted in an attachment 29 secured to a holder 31 by means of a journal 30 so as to be swingable in the vertical plane, said holder being arranged on the slide 4 and adapted to be displaced at right angles to the direction of movement of this slide. Guide bar 28 can be locked to attachment 29 by handle 32; attachment 29 can be locked to holder 31 by handle 33; holder 31 can be locked to transverse slide 4 by handle 34. In grinding toothed tools such as cutters, reamers and the like with obliquely cut teeth, the sequence is as follows: The cutter 10 having been clamped in the spindle 9 the spindle 31 of the grinding disc 3 is adjusted into the proper vertical position relatively to the spindle 9 by raising or lowering the standard 2. The table 5 is moved to bring the roller 26 on the lower end of rack 25 opposite the journal 30 of the guide bar; with the parts in this position, the latch 19 can engage the aperture 18 of the dividing plate. Clamp 24 is released, whereby the spindle 9 can be rotated relatively to the dividing head 8. The spindle 9 is now turned so that a suitable point a on the edge of a tooth 101 will be situated as high as the centre line of the spindle at that point of the grinding disc which is caused to work in the grinding operation; this adjustment is effected with the aid of an indicator 40. The carrier disc 21 is freed from the spindle 9 by releasing the clamp 22 and is. rotated until the pin 23 enters one of the dividing apertures 17 in the dividing plate 16, whereupon the disc 21 is again locked to the spindle 9 by the clamp 22. To set the guide rail to the correct inclination, the latch 19 is disconnected; the handle 33 is loosened so that the guide rail may turn about its jounal 30. The table 5 is displaced to bring another point on the tooth 10<SP>1</SP> in contact with the indicator 40; the spindle 9 is then turned until the indicator reads zero, this turning of the spindle moves the guide rail to the correct inclination, whereupon the handle 33 is tightened to secure the guide rail in adjusted position. Adjustment to grind the desired clearance angle on the teeth is effected as follows: The dividing plate 16 is locked in zero position by latch 19 and the spindle 9 is locked by handle 24. The pin 23 is withdrawn from an indexing aperture and the disc 21 freed from spindle 9 by loosening handle 22. The disc 21 is rotated counterclockwise, the angle being indicated by the side 20 and again locked to spindle 9. The latter is now released by loosening handle 24, whereupon the disc 21 and spindle 9 are turned until pin 23 again engages the indexing aperture. The latch 19 is then withdrawn to free the dividing plate 16. The guide rail may be replaced by a curve deviating from the rectilinear shape according to the shape of the edge of the work-piece. Specification 503,431 is referred to.