Patent GB-190004852-A (GB)
Title: Improvements in and relating to Apparatus for the Reproduction of Type Written Matter
Inventor: EHRLICH FRIEDRICH ERNST PAUL
Filed: 1900-03-14
Granted: 1901-03-14
Abstract: 4852. Ehrlich, F. E. P. March 14. Type-writers.-Relates to type-writers in which a perforated paper strip is produced at the same time that the original document is written, the strip serving afterwards to produce duplicate copies by passing it through the same machine as often as may be required. The type-bars 1 are connected by links 2 to the key levers 3, which are pivoted at 5. The strip to be perforated passes from a roll 8 to a roll 9 bearing a ratchet-wheel 10 with which engages a pawl 11. The pawl depends from the rear end of a lever 12 pivoted at 12a and bearing at the other end a universal bar 15. The strip is thus advanced a step as each key lever rises from the depressed position. On the rear end of each key lever rests a stud 22 carried by a lever 21 which bears at its further end a similar stud 20. The levers 21 are pivoted at 21a in a frame 21b, which can be locked in the raised position indicated by dotted lines in Fig. 1 when it is desired to throw the punches out of action. The studs 20 act on the spring- controlled plungers of the punches 17, a perforation being made in the strip each time a key is depressed. The shift key is connected by trip actions with two punches, so that one perforation is made when the key is depressed and another when it is raised, which may be after several characters have been printed. A special perforation is made at the conclusion of each line, and another may be made at the end of the page, this perforation serving to actuate a bell or other alarm when the strip is being employed subsequently for duplication. To reproduce the writing, the punches are thrown out of action and the strip is passed over the open mouths of vertical air passages 25 in connection with an air-exhausting device. The admission of air to one of the passages 25 causes the corresponding flexible diaphragm 26 to be sucked into the vacuum chamber 30, so as to actuate the double valve 27. The outlet 29 is thus closed, and communication is established between the bellows 31 and chamber 30, the key lever 3 being therefore depressed. The shift key is similarly actuated, but it is held by a locking-detent until the second of the aforesaid perforations is reached, when the detent is released. At the close of the movement of the paper-carriage towards the left, a projection 57, Fig. 7, comes in contact with a bell-crank lever 55, and causes the pawl 56 to engage the crown ratchet-wheel 53 and turn the platen through one line space. Immediately afterwards the perforation made at the end of the line comes into action, causing the exhaust of air from the pipe 47 and bellows 46. The bellows collapse as shown in Fig. 7, and are locked by the latch 50. A friction roller 43, carried by the bellows, presses the ribbon 42 against a continuously-rotating roller, and the carriage is thus drawn to the right in readiness for printing a new line. A stop 58 attached to the carriage releases the latch 50, and enables the bellows to return to their normal or expanded condition. Compressed air may be used instead of rarefied air in the machine.