GB639664A - Printing press - Google Patents

Abstract

639,664. Printing-machines. CHANDLER & PRICE CO. June 25, 1947, No. 16763. Convention date, Aug. 2, 1946. [Class 100 (ii)] A machine which is similar in construction to a platen machine but is constructed with a curved impression surface 16 is described in connection with a machine similar to a Gordon platen machine. The impression surface 16 is mounted in a fixed frame and is rotatable about an axle 18 so that it can be moved to the position shown in Fig. 1 to receive the sheets, and is finally moved to the position shown in Fig. 3, and held therein by a cam-operated locking device 71 which engages notches 70 in spaced arms 68 secured to the surface 16. The frame 5 carrying the type bed 26 which is pivotally mounted at 27 in the frame is then moved about a pivot 7 so that the bottom edge of the bed engages the sheet, and further movement of the frame 5 causes the type bed to roll over the curved platen so as to print the impression line by line, and the pivots 27 and 7 are so related that the rolling motion of the bed over the platen occurs without slip. The curve may be part of a circle, oval, or ellipse. To maintain a constant printing pressure, the type bed 26 is acted upon by a toggle mechanism 32, 36, 39, 42, controlled by a cam 46 on a shaft 47 driven by a chain from a wheel 58 on the shaft 7. The pressure due to the connecting-rods 13 which oscillate the frame 5 is thus supplemented by a variable pressure due to the shape of cam 46 which is designated to compensate for the variation due to the action of the rods 13. The link 39 of the toggle is formed of two telescopic parts separated by the action of a spring which yields if excessive pressure is applied, e.g. by the feeding of a plurality of sheets. Pressurecontrol means such as the hydraulic control described in Specification 639,665 may also be used. To prevent a double impression the type-bed 26 is maintained by a dwell on the cam 46 in the position shown in Fig. 3, until the frame 5 is reversed to carry the bed away from the curved platen. If desired the bed 26 can be mounted on the fixed frame and the curved platen on the oscillating frame. Specifications 14805/05, [Class 100], and 174,445, [Class 100 (ii)], are referred to.