Patent GB-190613096-A (GB)
Title: Improvements in or relating to Cutter-grinding Machines and Cutters Shaped thereby.
Inventor: DUNCAN HAROLD MALCOLM
Filed: 1906-06-06
Granted: 1906-11-22
Abstract: 13,096. Duncan, H. M., and Pierpont. F. H. June 6. Microscopes.- Relates to a machine for grinding cutters used in the shaping of punches whereby the matrices in monotype and like machinery are formed. The cutters are held in a chuck carried by a h e a d which is constrained in such a manner that it can only be moved in a predetermined and invariable path from the grinding-lap to a microscope provided with hair-lines in the eyepiece whereby the grinding of the tool may be gauged. The grinding-lap A, Fig. 1, which is composed of metal charged with diamond dust, is mounted in a head B<1> and driven from any suitable shaft by the pulley B'. The head B<1> is mounted on a table. which is adjustable transversely to the axis B. The work G is held in a chuck E<6>, Fig. 1, rotatably mounted on a tool-carrying head E which is attached to the frame D by a Cardan joint. Lugs D<1> on the frame carry horizontal pivots E<4> which engage with a block E<3>, which also engages with two pivots E' in a line perpendicular to the horizontal axis between the pivots E<4>, and carried by the jaw E<1> on the head E. This allows the head to turn about both an horizontal axis and an axis at right-angles to it which intersect one another at the centre of the block E<3>. An arm E<5> projects obliquely from the jaw E' and engages with a guide-plate F attached to the frame. To determine when the tool is sufficiently ground, it is examined by a microscope H held in an extension D' of the frame. The eyepiece of the microscope is provided with hairlines H<1>, Fig. 17, which can be traversed across the field of view by a worm arrangement, and, if desired, with a cross-line H<2>. Light is allowed to enter the microscope through a slot H<8> in the casing of the instrument, and is reflected down the optical axis of the instrument through the objectglass H<9> on to the object to be viewed, and at the same time a small mirror H<10> is provided to reflect light up from behind the object. By the simultaneous use of these two devices, it is stated that additional clearness is obtained. The work is transferred along a predetermined and invariable path from the grinding-lap. to the microscope. Movement of the tool-carrying head E about the axis between the pivots E<2> of the Cardan joint is prevented by the arm E<5> being constrained to move in a vertical slot in the guide F, the motion being limited by a projection D<3*> on the head E coming into contact with a stop D' on the frame. By these means the tool can be brought into position under the microscope by merely moving the arm E<5> until the head E comes into contact with the stop D<3>. To gauge the tool, a master-tool is first inserted and viewed through the microscope in the gauging position, and the lines H<1> are adjusted until the cutting-tool lies between them as in Fig. 17. The master-tool is then removed and the tool to be operated upon inserted in the chuck and ground by the lap A until its edge lies between the lines H<1> when the tool is in the gauging position.