US2457133A - Fragmentary character printer - Google Patents

Description

Dec. 28, 1948. v E. M. DELORAINE 2,457,133

FRAGMENTARY CHARACTER PRINTER Original Filed Oct. 18, 1941 E 3 l5, 7WD 3190 47/7 .577! 6TH 77H START BAA/D BAND BAND BAND BAND BAND 5/] ND I57 BAND l 7ND HAND 3P0 BAND 4 TH BAND 57H BAND I l I 67/4 BAND 77 7 BAND h 3P0 BAND 7ST BAND I I I I I I I I 4 BAND 57w amvo I l L J L J L J L J 7m awn I I I. I I ,I I

IN VEN TOR.

EDMOND MAI/1916f DELOPA/NE 2ND BAND aka BAND 4% BAND 5TH BAND 6TH BAND 7TH BAND I57 BAND 7ND BAND Patented Dec. 28,1948

to InternationaliStandard Electric Corporation, New York, N. Y;., a corporation of Delaware" Original application October 18,1941, Serial No. 415,554, now 'Pa'tent lio. 2,365,458, dated De-' cembcr 19, 1944.1 Dividedand this application September 6, 1944, SerialNo.'552,887. InCan ada June 24 4 an: (or. Nil-30) This invention relates to printing telegraph systems and more particularly to a printing telegraph for radio use. This application is a division of my copending applicaton Ser. No. 415,554,

filed October 18, 1941, now Patent No. 2,365,458,

cation.

An object of the invention is to provide a facsimile printer of rugged construction, light in weight, and adapted for portable use, especially for communication with airplanes.

Another object of the invention is to provide a facsimile printer in which the number of mechanical movements of the apparatus is limited to a very few,.these being of such a nature asto render the amount of mechanical maintenance on the equipment almost negligible.

A further object of the invention is to provide a. facsimile telegraph printer which will avoid the vertical displacement of the letters on the tape when there is anapp'reciable. difierence in speed between the transmitter and the receiver, such speed difference in the present invention resulting only in the slanting slightly forward or backward of the characters,-the direction and degree of slant serving as a guide to indicate the direction and extent of adjustment required by the printer motor governor.

One embodiment of the invention is disclosed in the accompanying drawings in which:

Figure 1 is a schematic representation of the printer mechanism and associated circuits;

, Figure 2 is a plan view of the printer chariot shown in Figure 1; I V

Figure 3 is a chart indicating the manner in which received impulses are formed into built up characters.

In my copending application referred to above a preferred embodiment of a transmitter is disclosed having a smooth, quiet, cam-operated mechanism of the sewing machine type. A drum, perforated about its circumference in a series of rows is driven uninterruptedly at a uniform rate by a motor. A key operated shutter is provided for each row of perforations, the perforations of each row being arranged according to the elements forming a character in a code. A hotoelectric, eliis o t oned w thin the drum perforations.

and the light from an external source is permitted to pass through the perforations of the drumto be received by the photo electric cell only'whenthe shutters are moved to uncover the The shutters are selectively with drawn by the manually operated keys, p

The photo electric cell is connected tof"fan amplifier, the output of which feedsfla Lradio transmitter so that when the keys areoperated a series of; coded impulses are transmitted. iIIhe perforations are preferably arranged in the drum so as to modulate the light beam to produce a start impulse and a plurality of character im pulses; In a preferred form of the invention the start impulses are at a different frequency thanithe signal impulses so as to be able to separate them at the receiver. To dothis the drumfis pe rforated With as many rings or circumferential rows of holes as there are characters'to be transfmitted. The number and grouping of the per-'- forations of any one ring is such that the beam of light directed through them from the 'out s'ide of the drum to the photo electric-cell inside would be modulated at approximately 540 cyc'l'e's for a short interval, say 30 milliseconds fora start signal, and thereafter in a series of impulses of about 800 cycles to represent the characters. I y In the preferred embodimentofthe traps mitter the perforations are grouped to transmit facsimiles of the characters selected, In-order to'do this the perforations in the drum'are ar: ranged to transmit each letter or character in seven horizontal lines, this number being selected to give a fairdegree of detail when the character is recorded. With a line signal of this kifid'the number of signals for each letter is consequently much higher'than in the Morse or five unit code. Figure 3 shows diagrammatically the impulse groupings for the characters E, 2, and "N in an arrangement where each character is divided into seven horizontal bands, impulses of the required lengthbeing transmitted in'proper're'la tive" position for each band and the bands trans-'- mitted in succession for the purpose ofoperating the printer which has means for recording the impulses successively to form a built up character, as will be hereinafter described.

*i'lfhe printerxas shown in Fig. .1 "comprises a motor 220 provided with known means, not shown, for maintaining a constant rate of speed sufficiently close to that of the transmitter to permit start-stop operation. In the present arrangement about to be described, speed variation within reasonable limits does not cause the printing of a wrong letter but the letters are printed slanting in one direction or the other, the direction of the slant indicating Whether the speed is high or low, and the degree of slant, the speed difference. Consequently, speed adjustments are easily maintained.

Motor shaft 22! is connected to a second shaft 222 by clutch 223 consisting of a pawl 224 and ratchet 225, fixed respectively on shafts 222 and 22!. Pawl arm 226 cooperates with armature 221 of start magnet 228, one terminal of which is con-v nected to ground and the other to the front'contact 229 of relay 23 which has an armature 23] connected to a grounded source of potential.

A cam 232 on shaft 222 engages a roller-233 at the end of arm 234 pivoted at 235. A link 236 connects arm 234 with chariot 231, which reciprocates horizontally in suitable guideways (not shown) under the influence of cam 232 and spring 238 connected to arm 234'. In the present embodiment the chariot supports seven styli 240 which are vertically movable in apertures inthe chariot against the tension of individual springs, not shown. A top View of the chariot is shown in Fi 2.

. A print hammer 24! is disposed above the chariot and a platen 242 over which passes an inked ribbon 243 and a papertape 2 44. The print hammer is mounted on an arm 245 pivoted atf246 and held normally against stop .24] by spring 248. The print hammer is oscillated by magnets 250 and 25! secured between the polepieces 252 of a permanent magnet, the armature 253 thereof being connected to the printhammer. The magnet and armature arrangement issimilar to that of a balanced armature loud-speakerunit.

One terminal of magnets 250-25| is connect ed to the amplifier 2 by circuit 255. The other is connected to contact 251, the tongue 2 58 there.- for being connected via circuit 256 to the amplifier. Relay 230 has one terminal connected to the amplifier via circuit 255 and the other by con; tact 259, tongue 258 and circuit 256, only when the cam is in stop position, tongue 258 being moved away from contact 25'! and into=engagement with contact 259 by an insulating pinififl carried by cam 232 which engages the tongue just as the cam reaches stop position, as shown in the drawing.

The printer operates as follows. Assuming the printer and transmitter motors are running at the proper relative speeds and that the trans;- mitter key has been depressed for the letter E sending out a series of spaced impulses com mencing with the cycle start signal, as shown in Figure 3.

On receipt of the start signal which enters the receiver 2H] and passes through the filterand amplifier 2! I, indicated by the block diagram of Fig. 1, relay 230 is momentarily energized and operates start magnet 228 by a circuit from its.

tongue, through front contact 229 and the, wind? ings of the start magnet to ground. The opera,- tion of the start magnet withdraws its armature 221' out of the path of the arm 226 of pawl 224, and the pawl in response to pressure from a spring, not shown, engages the teeth of ratchet 225 causing shaft 222 and cam 232 to rotate.

The rotation of the cam-carries arm 234 and 4 chariot 23'! toward the right of the drawing, the cam being so synchronized with the transmitter drum that each stylus 240 operated for the first band traverses a distance over the platen while under the printhammer equal to the width of a letter while the first band is being transmitted, and then passes beyond the printhammer. The first band is followed by the second band. During reception of the second band each stylus Operated moves under the hammer so that on operation'thereof thestylus contacts the paper tape making a mark in said second band, and so v on, for the remainder of the bands.

high part of the cam passes from under roller 233 and the arm is snapped back to the left by spring 238.

A pawl 265 connected to arms 234 and 268 by pivots 266 and 261 respectively, arm 268 being supported on a pivot 269, is used to operate a tape feed mechanism. During the movement of arm 234 to the right, the pawl drops behind a tooth in, a ratchet wheel 210 provided with a detent, not shown, secured to a roller which cooperates with a pressure roller 2' between which rollers paper tape 244 passes. The reverse movement of arm 23 4 toward the left causes the pawl toturn the ratchet and advance the tape a ,distanceof one letter space. Suitable means, not shown, are used for feeding the ribbon.

On the completion of the reception of a letter, cam 232 carriesjinsulating pin 260, into engagement with contact tongue 25,8, breaking the circuit to, magnets25ll and 254 and connecting the amplifier via contact 259 again to start relay 235 toawaitreception of the next start impulse. -,Pawl arm 226 of, the clutch strikes armature 221 disconnecting the paw-l from the ratchet 225 and stops rotation of the cam until receptionof the -r-1ext.=:startpulse.v

The movementof the styli is very sensitive and the;printhammer follows the signalling currents Iaccuratelythe characters being printed to conform-to the perforations in the transmitter drum.

a! printer of the kind described, the only nonprinting function required is the word space and the space bar-v of the transmitter when operated merely causes the transmission of a start signal causingthe receiver to start and stop in the manner-above described, and since no impulses areltransmitted to actuate the printhammer the unmarked tape is advanced the distance of a word space;

While the. present invention has been disclosed with' 'reference to specific embodiments thereof, it will be understood that these embodiments are merelypresented by way of example and that many modifications of the invention will be sugglestedthereby to those skilled in the art without departing from the spirit or scope of the inven ion.

What is claimed is:

in a facsimile printer a record surface comprising a paper tape, a stationary platen therefore, an inked ribbon disposed over said tape, a printhamme'r disposed over said platen means for moving said printhammer in response to signal impulses, a chariot, a guideway in which said chariot may move between said printhammer and inked ribbon, a plurality of diagonally disposed styli movably supported in said chariot and arranged when struck by said printhammer to cause said ribbon to mark the paper tape, a pivoted arm arranged to be oscillated, a, link connecting said arm to said chariot whereby the chariot is moved in said guideway corresponding to the movement of said arm, a single-cycle rotary cam swinging said arm uniformly in one direction for printing and releasing it for rapid return, and means operated by said arm in its return movement to feed the paper tape.

EDMOND M. DELORAINE.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number UNITED STATES PATENTS Name Date Kleinschmidt Jan. 31, 1939 Devaux Dec. 3 1940 FOREIGN PATENTS Country Date France Apr. 22, 1936 France Feb. 8, 1937

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