Patent GB-190101079-A (GB)
Title: Improvements in or relating to Matrices and Apparatus for Milling Justifying and Measuring these and other Bodies.
Filed: 1901-01-16
Granted: 1902-01-16
Abstract: 1079. Pierpont, F. H., and Lanston Monotype Corporation. Jan. 16 Milling.-Relates to a milling and measuring machine, specially suitable for reducing matrices, such as are used in monotype casting and setting machines of the Lanston class, to uniform length and depth of drive, but applicable to other bodies. Two headstooks K, carrying milling-cutters J, J', are accurately adjustable on a bed A by micrometer screws K<2>. A cross-slide C, operated by a hand-lever C<6>, has jaws D, D<1>, Fig. 4, between which the matrix blank L is gripped. The jaw D is vertically adjustable by a micrometer screw D' and disc D<5> while the forward position of the slide C is limited by a micrometer screw B<2> and disc B<3> carried by the fixed slide-way B. A plate E', secured on the slideway, has a boss E containing a needle holder F<1>, Fig. 7, with a needle F projecting through a cap E<3> on the boss. The holder is pressed forward by a spring, and has a lug F<3> engaging a cam F<5> with a handle F<6>, by which the holder may be locked in the forward position or may be retracted. A boss G', secured to, but insulated from, the plate E<1>, carries an ordinary micrometer screw G with an arm G<3> carrying a graduated quadrant G<4>. An electromagnet H, insulated from the plate E<1>, is connected to a source of electricity, which is also connected to the cam F<5> or other convenient part of the machine. The armature H<5> can engage with the deeply-indented scale G<4> when attracted. A handle H<3>, pivoted on the magnet yoke, has a knob H<4> projecting freely through a slot in the quadrant, the left side of the slot being covered with insulating-material. The micrometer screw G is so adjusted that, in the operation of measuring a matrix drive of normal depth, contact will occur between the screw and the holder when the armature is over the zero of the scale G<4>. If the knob H<4> is moved to the right to touch the right side of the slot, the circuit is completed without movement of the screw, thus locking the quadrant in the zero position, or, if moved to the left, the circuit is broken without movement of the screw, thus preventing sparking between the screw and holder. To operate on a blank, the lower jaw D is set by means of the micrometer screws D<4>, B<2> according to a chart, so that the matrix, when placed on the jaw, will present a certain spot on the character to the needle F, which is locked in its forward position. The operator slides the matrix L into contact with the needle, and then grips it by the upper jaw D'. The needle is then drawn back to clear the matrix by the cam F<5>, and the slide C reciprocated to pass the matrix between the correctly-adjusted cutters J, J<1>. The matrix is then released, and the micrometer screw G drawn bick to its furthest extent. The matrix is then pushed against the cap E<3>, pushing the needle further in, the micrometer screw being advanced till contact is made and the quadrant G<4> locked. The error in the depth of drive can be read on the quadrant to one ten-thousandth of an inch. If the drive is too small, the matrix is discarded, but, if too great, the cutter J is advanced by its micrometer to remove the excess in a second milling operation. If the machine is not required to correct the length of the matrix, the cutter J<1> may be omitted. The process described allows matrices &c. to be finished by milling, without subsequent grinding &c.