Patent GB-204923-A (GB)
Title: Improvements in printing telegraph machines
IPC: H04L15/34
Filed: 1922-04-03
Abstract: 204,923. Kleber, O. L. April 3, 1922. Electric type-wheel machines. - A type-printing telegraph has a circuit-breaker for disconnecting a source of energy at the receiver when, say, the message is completed and operated under the control of a selecting mechanism which is itself controlled by the received impulses, the circuitbreaker being operated by a received impulse, independently of the selecting mechanism, to connect the source of energy at the commencement of a message. The machine described has a type-wheel or drum adapted to be selectively positioned by impulses of different duration representing dots and dashes of the Morse code. A modification is described using two type-wheels, the second being positioned whilst the first is printing, the two printing two letters side by side, the paper being fed a distance corresponding with two letters between each double imprint. The receiver at the sending station may be used to record the message sent. The type-wheel 1 is loosely mounted on a shaft 2, Figs. 5, 6, 14, and is rotated therefrom through a friction drive comprising a disc 3 preferably integral with shaft 2, and a friction disc 4 pressed against the opposite face of the wheel 1 by a pronged spring 8 carried by a collar 5 fixed to shaft 2 by a set-screw. The shaft 2 also carries a chain-wheel 13 serving to drive a circuit-controlling device described below. The type-wheel carrying the required characters on its periphery comprises a disc on one face of which are four concentric series of laterally projecting " dot" stops 16, Fig. 31. Four concentric guide rails 17 are provided between the stops 16, as shown. In the type-drum modification separately described below, these stops and rails are arranged on the cylindrical surface. " Dash" stops 19 are provided as upstanding extensions of the guide rails. Alternatively, the " dash " stops may be arranged m four concentric series within the " dot" stops. The forward ends of the rails are bent to provide slides 43, 50, 46 in stepped relation. A rail 20 extends from the last pin 83 of the series to a pin 41 which determines the initial position of the wheel, and a rail 21 bridges between the second and third rows of stops. The various stops are so disposed that each corresponds with a particular type on the periphery and is in fixed radial relationship therewith. The dot and dash stops co-operate with a dot finger 18 and dash finger 23 to control the rotation of the type-wheel, the fingers 18, 23 being controlled by a magnet 22 intermittently energized in accordance with the received signalling impulses. The fingers 18, 23 are respectively pivoted at 39, 24 to oscillate towards and away from the wheel and are also mounted to allow movement radially across the face of the wheel. The upper end of finger 18 is guided by a slot in a strip 25 secured to the finger 23, and the lower end is arranged to allow a limited yielding movement against a spring 37 to cushion the arrest of the type-wheel and minimize wear and tear of the stops under rapid actuation. A spring 38 urges the fingers towards the type-wheel, and the fingers are arranged so that when either is in engagement with the wheel the other is out of engagement. To prevent recoil of the type-wheel a ratchet-toothed check ring 112 is provided having as many teeth as there are type characters and engaged by a spring detent 114. The armature 40 of magnet 22 has a bracket member 27 bent over to engage the fingers and withdraw the dot finger 18 when the magnet is energized. In its initial position the wheel is held by the dot finger 18 in engagement with stop 41 between rail 20 and outer rail 17. When an impulse is received, the finger 18 disengages from stop 41, and the type-wheel rotates. If the received impulse is short, finger 18 immediately re-engages the type-wheel and is forced laterally by slide 43 into engagement with stop 44 in the second row. With a long impulse, slide 43 is cleared. Similarly, subsequent impulses determine whether the dot finger shall continue in the same row of stops, or move laterally to the next row. The wheel may be arrested either by the finger 18 engaging a " dot stop or the finger 23 engaging a " dash" stop, and the stops are so disposed that each combination of impulses composing a code signal finally arrests the type-wheel with the required character in the printing position. Return of the type-wheel to its zero or home position is described below. After the arm 84 has moved to effect the impression and ink-ribbon movements described below, its continued movement causes it to engage the upper end 18<a>, Fig. 14, of the dot lever 18, which is thus disengaged from the type-wheel. The latter then rotates until a cam 234, Fig. 31, engages a finger 96 on the rock shaft, Fig. 5, thus disengaging the knifeedge and worm, and allowing arm 84 to be returned by spring 88. This releases the dot finger 18, which returns to the type-wheel and engages stop 41, arresting the type-wheel in the required position. A switch arm 271, Figs. 1, 69, normally contacts with a contact 269. When it is desired to transmit a message, arm 271 is slowly moved to break contact, and in this movement a pivoted member 273 on arm 271 momentarily opens a contact 270. This effects starting of the motor as described below. A knife-switch cooperating with the above switch 271 comprises a beam 279 normally held in the position shown in dotted lines, Fig. 59, against the action of a spring 281 by a catch 300 released by a core 304 when its solenoid 305 is energized. Beam 279 carries contacts 282, 289, 290, 291, adapted to bridge corresponding pairs of flexible contacts 283, 292, 293, 24. A transverse knife switch 272 is closed by the beam assuming the full-line position, but is opened and beam 279 moved over, by a core 310 when solenoid 308 is energized. A relay 362, Fig. 55, has a contact 349, which is rotated to prevent sticking of the armature contact 346. Normally, the armature of relay 362, Fig. 69, is held by current over the main line 370. Momentary interruption at the sending station (accomplished by arm 271 thereat opening contact 270) releases the armature, and closes a circuit from a battery 386, through solenoid 305, which releases the catch 300, Fig. 59. Contacts 283 are thus bridged, closing a circuit through supply leads 398, 399 and motor generator 228. This set drives certain of the receiver mechanisms already described, and also a transmitter. It also supplies current for effecting certain of the solenoid-operated movements. The receiver is stopped on receipt of a predetermined signal which momentarily arrests the type-wheel so that a pivoted contact 353, Fig. 37, engages a cam-shielded contact 352, Fig. 31, the arrangement being similar to that of pawl 239 and contact 238 described above;. This euergizes solenoid 308 and initiates the opening of switch 272 and moves arm 279, Fig. 59, towards the dotted line position. A circuit closed through jaws 292 keeps solenoid 308 energized to complete movement of arm 279 until retained by the catch. The supply circuit to the motor set is thus broken. To economize time a modification may be used in which, whilst one type-wheel is being returned to its initial position, a succeeding character is being selected on another. Except as regards features mentioned below, this form of receiver is a duplication of the single typewheel machine. In a receiver of this type described in detail, the selecting stops and type characters are arranged on the peripheries of two drums frictionally driven from a common shaft, and placed side by side so that two properly spaced characters are printed. The paper is shifted to the extent of two letters, only on completion of the second impression. This is effected by omission of one of the shifting camcontact devices. The selecting mechanisms are alternately disabled by a pivoted T-shaped contact lever thrown to one side or the other by two solenoids and thus breaking and preparing circuits to secure alternate action. Hammer - impression arrangements. -The printing is effected by energizing a printing solenoid 47, Fig. 43, at the proper instant, its core 113 striking an abutment 94 on a printing lever 114 whereby the printing head or hammer 115 strikes a typewriter ribbon 132 and paper sheet 133 against the selected character on the typewheel. In order that the printing action may occur automatically, and only after the receipt of the requisite type-selecting impulses, and independently of the selecting-mechanism, the following delay-action mechanism is employed to control the circuit of the solenoid 47. A member 66 is loosely mounted on a shaft 56, Figs. 5, 6, 27, driven by chain from wheel 13, and is driven, when free to rotate, bv friction discs 67, 68 secured to the shaft. Member 66 has cams 71, 71<a> coacting with brushes 74, 74<a>, to effect circuit closures. Movement of member 66 is arrested by pins 72, 73 one or other of which is engaged by the hooked end of an arm 84 capable of swinging movement on a vertical axis at 87, Fig. 6. Pivoted to arm 84 is an arm 89 with a depending knife-edge 90 adapted to engage, when arm 89 is depressed, in a worm 62 driven from shaft 56 through gear 59, 60, but when arm 89 is raised the knife-edge is clear of the worm. Arm 84 is urged in one direction by a spring 88 and assumes the position shown in Fig. 5 when the knife-edge and worm are disengaged, but is moved in the opposite direction by the worm when engaged by the knife-edge. Arm 89 is raised at the receipt of each signal impulse by an arm 92 on a rock-shaft having a finger 99 raised by a lever 101 on the armature shaft 103 of the selecting magnet 22, lever 101 acting through an intermediate lever 102. So long as signal impulses are arriving to select a character, arm 84 is repeatedly returned by spring 88, the knife-edge never being engaged with the worm for a time suffi