Patent GB-190228772-A (GB)
Title: Improvements in Platen Presses for Printing, Stamping and other purposes
Inventor: THOMSON JOHN
Filed: 1902-12-30
Granted: 1903-03-19
Abstract: 28,772. Thomson, J. Dec. 30. Platen presses.-Relates to improvements ' in platen printing and stamping presses. (1) Means for fixing the chase on the bed, Fig. 1. The chase C is secured at the upper end by a latch 1 having a screw-threaded opening 3, through which passes a screw 4 journalled on the bed B. The screw 4 is rotated by a pair of bevel gears 6, 7 from a horizontal shaft 8 having a hand-wheel for turning it. When the end of the hock 1 engages the chase C and is pressed thereon, it operates to jam or lock the screw and prevent accidental movement. (2) Means for adjusting the effective length of the connecting-rods which operate the platen, Fig. 3. The platen D is operated by rods A connecting it to crank-pins 28. In the eye of each rod A, surrounding the crank-pin 28, is an eccentric sleeve or bush 21, having two keyways 24, 25 opposite each other, either of which may be secured by a key 27 and keyway 26 ithe eye of the rod A. Threaded holes 21<a> may be made through the bush for the insertion of screws for forcing it out of the eye. (3) Means for preventing fracture as the platen moves on its supporting-guides, Figs. 4 and 5. The platen D rocks and slides, by means of its rockers 30, upon the seats 32 on the machine frame. As the platen slides finally up to the bed with its face D<1> vertical, it is guided or held in that position by lugs 34, 35 on the extension D<2> of the platen, engaging above and below the ends 41 of the seats 32. The lugs 34, 35 are frictionally attached by means of dovetail-headed bolts 39, 40 engaging the dovetail slots 36 in the lugs, so that these lugs may move in case of undue strain. In a modification, the lugs are in the form of dovetail blocks engaging dovetail slots on the projection D<2> and clamped therein by set-screws. (4) Arrangement of the platen to rock and slide upon rollers in place of fixed rockers, Fig. 10. In the platen D are journalled rollers 62 on studs 63, and these run upon the seats 61, the platen being guided in its movements by the usual controlling-cam. (5) The toothed arc 79, Fig. 10, to which the platen adjuster slide and bar are connected, is made separate from the platen frame, and is attached to the ribbed seat 82 by a screw. (6) The platen is guided in its final movement up to the bed C by means of pins 100 in the ears D<2> engaging in the slots 103 on the framing. The pins 100 are eccentrically mounted in the ears D<2>, and are fixed by screws 102, and yield in their seats in case of undue strain. (7) The tympan is secured to the face of the platen by means of bars 130, 131 clamped to the edges of the platen by screws 132 and 135 respectively, springs, as 134, surrounding the screws and pressing the clamping-bars outwards from the platen when the screws are unscrewed. (8) The latches of the platen adjuster or throw-off bar are operated as shown in Fig. 16. The latches 117 slide in seats in the adjuster bar 108, and are pressed by springs 115 so that their noses 109 engage the notched piece 110 on the platen. The latches are pivoted at 120 to levers 121, the ends 122 of which engage and act as cams against the surfaces 123 on the bar 108. When two latches are used, the levers 121 may be connected one to the other by an operating-bar 125. (9) Means for mounting and operating the frisket or gripper fingers, Fig. 10. The fingers 207 are clamped by bolts 208 on a frame 210 pivoted in side pieces 212, screwed to the platen, by eccentrically-seated pivot pins 214 fixed in the split pieces 212 by clamping- screws. On the frisket frame 210 is a downwardlyextending cam-arm 216, which engages a fixed pin 220 eccentrically seated in the framing. The camgroove is formed to operate the fingers 207 as the platen moves to and from the bed C. The frisket frame is in two parts pivoted together and held with the two parts 227, 228 abutting, by a spring, so that the fingers 207 may be forced down on to the platen when the latter is in the open position shown.