Patent GB-259818-A (GB)
Title: Improvements in and relating to the manufacture of printing plates
IPC: B41D3/00
Filed: 1926-03-02
Abstract: 259,818. Marks, E. C. R., (Wood Newspaper Machinery Corporation). March 2, 1926. Stereotype, casting and finishing. A number of vertically adjacent stereotype plates are cast integrally from part cylindrical matrices and are cut up to form the individual stereotypes by severing the member connecting the printing-surfaces. Means are also provided to enable a double-width or a single-width plate to be cast. The mould comprises a water-cooled cylindrical core 13 rotatably mounted on a central pillar 12 in the frame 10, and a water-cooled segmental back 18 movable from the casting position into the vertical and inclined dotted line positions shown in Fig. 5. The back is pivoted on a shaft 17 in frames 16 mounted on rollers 15 running on transversely-adjustable tracks 14, and is connected bv links 53 and cranks 52 to a hand-operated shaft 51. Rotation of the shaft first draws the back into the vertical dottedline position, further movement tilting the back through the engagement of a stop 54 therewith. The back is formed with a groove. 62 in which is placed a semicircular strip 61. T-shaped in crosssection, which serves to hold the adjacent edges of the two matrices. When a double-width plate is to be cast, the strip 61 is replaced by a block which prevents bending of the matrix at this point. For casting a. single-width plate in the top half of the mould, a T-shaped foot-ring extending completely across the mould and holding the matrix in the ordinary way, is used. The, strip 61 is supported bv two spring-pressed rods 68, Fig. 1, mounted in a platform 70. so that, when the back is retracted, the strip will be moved away from the core and will serve to stop the matrices. Each of the side edge of the back is provided with two vertical aligned shafts 75, Fig. 21. carrying the matrix-bars RO which are adapted to be held in closed position by springs 73 on the shafts, handles 77 being provided for facilitating opening. Mounted on the shafts 75 one at the top and the other at the bottom of the back, are two arms 74 arranged to engage with the matrix. bar locking-cams. The matrix-clips 88 are provided with studs 87 connected by links 86 to eccentrics 81 on the bars 80, the eccentrics on the separate matrix-bars being connected together for simultaneous operation. The adjacent edges of the clips are formed with notches 90 for receiving the strip 61 when that is used, a modification not provided with the notches being described for use when a double-width plate is cast. After a cast has been made, the back is moved away from the core, this also causing, through the medium of a cam 56. Fig. 5, on the shaft 51, a lever 59 and a link 60, the movement of saws into position for trimming the plate. The groove in the cam 56 is in two parts, one for effecting the movement of the saws. and the other shaped so that the position of the saws is not altered when the back of the mould is tilted. The saws, which are rotated continuously from a main shaft 20, Fig. 1, are mounted on brackets 46 pivoted on a shaft 47. and are normally pinned together for simultaneous movement. Two saws 49, 49a are mounted on the lower bracket, and two 49b, 49c on the upper bracket at the correct distances apart for trimming the edges and for separating the individual plates and the riser, and the saws are detachable to enable the unnecessarv ones to be removed when a double-width or single-width plate is cast. After the mould has been opened and the saws moved into the position, the core is set in rotation by means of a clutch 26 adapted to stop the rotation after half a turn, thus cutting and trimming the plates. Mounted on the back 18 are two pairs of spring-pressed, pivoted fingers 66, 67 Figs. 1 and 17, for separating the plates from the core. The fingers 67 for removing the lower plate are arranged farther from the back than the fingers 66 so that the lower nlate is pushed farther than the other one to facilitate their removal. When the back of the mould is retracted. the fingers are turned on their pivots by engagement with the edges of the cast plate, but on the return movement of the back after the core has been rotated, the fingers are prevented from turning and so strip the plates from the core. The plates are delivered on to upper and lower platforms 70. 71 respectively, the riser being temporarily held in its cast position by a projection on the core, and the waste piece between the plates, severed by the saws 49a, 49b falls on to the lower platform 71. The upper platform 70 is detachable to enable the doublewidth plates to be removed.