Patent GB-719468-A (GB)
Title: Improvements in or relating to typographical composing machines
IPC: B41B11/06
Filed: 1951-08-28
Abstract: 719,468. Type-bar-making machines. MERGENTHALER LINOTYPE CO. Aug. 28, 1951 [Sept. 2, 1950], No. 20256/51. Class 100 (3). Magazines; distributing-apparatus.-A typographical line-composing machine of the kind having a plurality of matrix magazines provided with shift means, locking means for preventing operation of the shift means, a solenoid for releasing the locking means, and a control switch in the solenoid circuit and normally open, but being adapted to close the circuit in preparation for a shift operation, includes a normally closed switch device controlling the solenoid circuit and located adjacent the discharge end of the magazine entrance, said device being adapted to be opened by the presence of a matrix in the gap between the entrance and the adjacent magazine, so as to prevent release of the locking means when the control switch is in a closed position. The magazines are selected in pairs, matrices being returned to A<SP>3</SP>, A<SP>4</SP>, Fig. 5, through entrances D3, D<SP>4</SP> from distributer bars D2, D<SP>1</SP>. The lock for the magazine shift consists of a pawl engaging notches in a wheel G<SP>1</SP>, Fig. 7, which pawl is withdrawn, to enable shift to take place by means of a handle, by the energization of a solenoid E<SP>1</SP>. The solenoid E<SP>1</SP> is supplied from a step-up transformer supplied from the usual A.C. source, and the solenoid circuit includes in circuit contacts 11 and 12 and switches E<SP>2</SP>, E', E<SP>4</SP>. Switch E<SP>2</SP> is closed by the usual shift-lock-release hand lever. Switches E<SP>6</SP>, E<SP>5</SP> are normally closed and opened if the shiftframe begins to move with a matrix lodged between the magazine entrance and magazine. Contacts 11, 12 are closed by a relay 4 in the circuit of which is a thyratron tube 2, of which the cathode 5 and screen 7 are grounded, while the grid 6 is tied to the cathode through a time delay condenser 9 and resistor 10. The heater 3 of the tube is also supplied from the transformer. Each magazine entrance is provided with an upper pivoted flap K<SP>1</SP> normally closed by gravity and a lower pivoted flap K<SP>2</SP> normally closed by a spring. If a matrix is across the gap, movement of the frame forces open one of the flaps, thereby opening switch E<SP>4</SP> or E5. The distributer screws D<SP>5</SP> and one side of a switch E<SP>3</SP> are earthed. The switch E<SP>3</SP> is normally closed, and is opened only when the shifter bar C<SP>1</SP> has reached its rightmost position, when no matrices are left in the distributer box C<SP>5</SP>. It follows that if a matrix is present in the distributer box or on a distributer bar, the bars are earthed, and the effect of this is to apply a negative voltage to the grid 6, stop the operation of the tube 2, and open the relay 4 and contacts 11, 12. Release of the lock can thus take place only if there are no matrices in the box, on the bars, or across the gaps between the entrances and the magazines. Green lamps L<SP>1</SP>, L<SP>2</SP> are provided to indicate to the operator that it is safe to shift the magazines. The lamp L<SP>1</SP> is lighted when the relay 4 is closed, that is, when the distributing mechanism is clear, while the lamp L<SP>2</SP> is lighted when switches E<SP>2</SP>, E<SP>4</SP>, E<SP>5</SP> are closed, that is, when the switch E<SP>2</SP> is closed the lamp will light, but if a matrix is across the gap it will at once be extinguished.