Patent GB-211264-A (GB)
Title: Improvements in engraving machines
IPC: B44B3/00
Filed: 1922-11-30
Abstract: 211,264. Corley, B. R. Nov. 30, 1922. Engaging.-An engraving-machine, using a needle for engraving letters and other characters on a coated plate and controlling this needle by a manually-operated transmitter carrying a stylus used for tracing the desired letter &c. on a master plate is arranged to allow of accurate spacing of the letter &c. irrespective of their width and shape, in a straight, arch, or inverted arch line, and of reproducing the marks on the masterplate to the same, or a different scale. A bed 27 carrying the coated plate is adjustably clamped on a guideway 28 on a work-bed 26 movable on guideways 23 of a support 22 on the machine column 21, Fig. 1. The needle 31 is carried by a support 32 mounted to slide and be locked in a holder 34 slidable in a guideway 35 pivoted in a bracket 37 mounted to slide vertically in guideways 38 on a carriage 40, Fig. 4. The holder 34 may be traversed along the guideway 35 by a rack and pinion 50, 51 and knob 53, and the bracket 37 is moved in the guideway 3B by a rack and pinion 55, 56 and knob 58. The carriage 40 is supported by two links 60. 61, Fig. 2, pivoted respectively to the carriage at 65 and the column 21 at 62 and to each other at 64. This mounting permits lateral movement of the carriage under influence of a transmitter 70 universally pivoted to it at 71. The transmitter is hung on a vertically adjustable universal pivot 72 comprising a sleeve 73 pivotally hung within a ring having an arm 76 mounted to slide vertically in a guideway on a bracket 78 pivoted to arms 80 of a bracket 81 adjustable vertically in the column 21 by a rack and pinion 95, 96 and knob 98. A pointer on the bracket 81 moves over a scale 100 to indicate the correct height of the fulcrum 72 on the transmitter 70 to give a desired ratio between the movements of the transmitter and the carriage 40. A bearing 110 on the transmitter carries a stylus 112 arranged to trace out character 114 formed on a master-plate 115, Fig. 5, slidable in a holder 116 adjustable on the base 118 of the column 21. Each character 114 has associated with it a mark 120 adapted to register with a mark 121 on the holder 116. Means for moving the work-bed 26 sideways to space the character includes a shifting bar 126 pivoted to the bed 26 at 125, Fig. 8, and slidable in the support 22. Mounted to slide on the bar 126 is a gripping head 128 pivoted to arms 130, 131 themselves pivoted at 132 to a shifting lever 133. The bar 126 may be locked to the head 128 and support 22 bv spring-pressed balls 141, 146 releasable respectively by rods 143, 152. the balls respectively exercising locking action as the bar 126 is moved to the left or the right in its step-by-step movement of the work. The shifting-lever 133 has a vertically adjustable fulcrum 160 similar to that of the transmitter 70 and carried by a bracket 166 attached to the bracket 81. The lower end of the lever 133 is provided with a fork 180, Fig. 1, engaging a pin 181 on one link of an endless chain 183 which passes round sprocket-wheels 184, guide-wheels 186, and the sprocket hub 187 of a wheel 188 rotatable by a knob 191. When the wheel 188 is turned, the lever 133 is swung sideways by the pin 181, imparting motion to the bed 26 through the bar 126. The wheel 188, which may be locked by a spring- pressed pin, is provided with sprockets 195 engaged by a chain 196 passing round a sprocketwheel 197 and above an upwardly and rearwardly inclined table 205. A pointer 206, Figs. 1 and 5, on the chain 196 is arranged to move over charts 207, 208 adjustable on the table 205 and having diagonally-disposed adjacent edges 210 and spaces 211, 212, Fig. 17<a>, each space containing letters or characters 213. 214 of similar width, the narrowest characters being arranged in the lowest spaces of the chart 207 and in the highest spaces of the chart 208. The charts 207, 208 are held spaced apart more or less according to the spaces to be given to adjacent characters of the engraving. The characters 213, 214 correspond in style and width with those on the master plate 115 in use. To assist in positioning the plate 30 correctly a scale 220, Fig. 1, is provided on the forward guideway 23 of the support 22 having on its upper and lower edges scales 221, 222 of which the latter is scaled one to two relatively to the former. The zero mark of the scale 221 is at the right-hand side and the zero of the scale 222 is below the five inch mark of the scale 221. Pointers 223, 224 on the bed 26 move respectively over the two scales so that when the pointer 223 is aligned with the five inch mark of the scale 221, both pointers are in vertical alignment with the needle 31, the transmitter 70 and the mark 121 on the plate holder 116. The needle 31 is normally held raised from the plate 30 by means of a button 231, Fig. 4, mounted on the transmitter 70, the button engaging one arm 232 of a lever the other arm 233 of which presses outwardly an arm 236 pivoted to the swinging carriage 35. The button may be depressed by means of a rod 242. Fig. 1, connected by its upper end to the shank of the button and by its lower end to one arm of a bellcrank lever 244, Fig. 2, the other arm of which carries a roll 248. The latter is engaged by a rod 249 on a lever 250 normally pressed by a spring to hold the button 231 raised, but adapted to be moved by a hand grip 254, Fig. 1, adjacent the operating handles 255 of the stylus 112 so as to lower the button 231 through the rod 249, lever 244 and rod 242. To permit of doing arch line work a rotatable work bed 260 is mounted on a shaft 261, Fig. 1, rotatable in a support 262 pivoted to the column 210 adapted to be swung over the bed 27 and be locked in place by a bolt engaging a slot in a stud 265. In this position the needle support is raised through the bracket 37, rack 55, and knob 58. The bed 260 is provided with concentric circles on its upper face and an edge degree scale to assist in positioning the work upon it. The lower end of the shaft 261 carries a pinion 275 adapted to mesh with a rack removably attached to the bed 27 at this time. When the bed 27 is traversed in the operation of the machine by the lever 133 this motion is imparted to the bed 260 through the pinion 275 and rack. In operation, starting with the several scales at zero, the knob 191 is successively turned to bring the pointer 206 into line with the first character, if the matter to be engraved, on the chart 207, and then with the same character on the chart 208, then with a space on the charts 207, 208, then with the second character, and so on. Each movement is imparted to the bed 27 through the lever 133, and the total space required for the engraving is finally read off on the scale 221. The bed 26 is now moved until the pointers 223, 224 registers with the zero of the scale 222 and the plate 30 is clamped on the bed 27 with the needle 31 centrally above it. The bed 26 is next moved to place the pointer at the graduation on the scale 222 previously read off on the scale 221, so as to space the two halves of the engraving equally from the centre line of the plate 30. The pointer 206 is now turned to the first character on the shaft 207, moving the bed 27, the master plate. 115 is moved so that the mark 120 of the first character to be engraved registers with the mark 121, the needle 31 is lowered, and the stylus 112 traces out the first character, moving the needle 31 similarly. The pointer 206 is then moved to the same character on the shaft 208, then to a space on the charts 207, 208, and then to the second character on the shaft 207, when the previous process is repeated. Each character is engraved similarly. A pivoted gauge 310, Fig. 2, may be used to indicate over the master plate when characters of different sizes are to be engraved from the same plate. For arch or inverted arch line work the bed 260 is swung into position, the needle raised, and engraving proceeds as above described. The adjustability of the pivots 72 and 160 allows of proportioning a character on the work-piece to any desired width relatively to the characters on the master plate and of predetermining the spacing of the characters.