Patent GB-280988-A (GB)
Title: An improved photographic type-composing machine
IPC: B41B17/06
Filed: 1926-07-27
Abstract: 280,988. Bawtree, A. E. July 27, 1926. Photographic type-composing; enlarging, copying, and reducing.-In an apparatus in which the characters are arranged on negative strips in a straight line, the strips or frames containing them bear projections, indentations, &c., one for each character, and so formed or placed as to represent the width of the characters to control the spacing mechanism of the machine. The strips are interchange ably mounted on the sides of a prismatic or polygonal frame adapted to slide in the direction of its axis and to rotate to definite positions to bring any character and strip to the optical plane of the machine. Means are provided for automatically focusing the lens and sensitive material holder to vary the size of the image As shown in Figs. 1 to 4, negative strips B are mounted in the sides of a prismatic tube A slidable on a tube H within which is carried a source of illumination. A star wheel F on the tube A co-operates with a grooved rod G to maintain the set strip B in position. The dark slide Y with the sensitive material and cover Z is mounted in grooves on a carriage W slidably mounted on a second carriage V and the optical system is mounted on a carriage T, the carriages T, V, being relatively movable by projections engaging cam grooves in a cylinder w operated from a handle S until the desired scale of enlargement or reduction is indicated on the dial x. Setting of the slide V vertically to a. position for the first character to be impressed is effected by depression a plunger f which through a flexible connection operates a pawl e and ratchet wheel d on a spindle c having pinions .engaging racks b on the slide Y. To vary the step of movement in a vertical direction, the plunger f is provided with a projection co-operating with a stepped disc g the setting of which determines the extent of its depression. A flexible connection j connected to a shoe on the slide Y and to a dial k transmits the movements of the slide Y to the pointer of the dial k. Lowering of the slide is effected by a plunger i which withdraws the retaining pawl h from engagement with the ratchet wheel d. The horizontal setting of the slide Y is effected by rotating a shaft l having pinions engaging racks on the underside of the carriage W. The sides of the prismatic tube are provided with tongues E separated by slots D corresponding to the left-hand side of each character, the tongues varying in length in such a manner that they fall short of a common maximum by an amount which equals the width of the character. On depression of an operating handle R, a bellcrank-lever Q is caused to engage a slot and move the prismatic tube to position the character exactly; at the same time the handle R by its engagement with a pin p on a crank on a shaft o causes the shaft o to turn and, by reason of the engagement of a cam o' on the shaft with a swinging plate t, moves the upper edge of the plate t from contact with the underside of the carriage W to lower it and the sensitive plate to exact position for exposure. Contact of the handle R with a pin r sets an exposure shutter for release on the return movement of the handle. The spacing movement of the carriage W depending on the character to be exposed is controlled by the plate t and a rod O co-operating with a sloping surface t<1> thereon. The rod O is slidably mounted in a block s pivoted to the underside of the lens carriage T and is operated by a projection on the handle R during its return movement to slide the plate, t to the left, Fig. 8, on the shaft t<3> and through contact of its surface t<4> with the carriage W move the latter a corresponding amount. The extent of the movement is controlled by a, lover J, Fig. 6, engaging a disc L pivoted to a plate M having a projection N in contact with the rod 0, the movement of the lever J being arrested by the tongue E presented thereto. The disc L is stepped so as to vary the spacing between the characters.