US2355369A - Multistylus facsimile recorder - Google Patents

Description

Original Filed Nov. 16, 1938 7 Sheets-Sheet 1 SQ us E \w )3 A QNW h M mg J. .4 1 g x a 1% ww um I I I I I r I 1N IIL. Ill Mu DWN 4| N.

. fa aw} INVENTOR wxzmy ATTORNEY Aug. 8,-1944. w. e. l-L FINCH MULTISTYLUS FACSIMILE RECORDER Original Filed Nov. 16, 1938 '7 SheefiSL-Sfifi? INVENTOR WWW mam A! ATTORNEY 1944- w. G. H. FlNCH 7 2,355,369

MULTISTYLUS FACSIMILE RECORDER Original Filed Nov. 16, 1938 7 Sheets-Sheet 5 mvsnora- ATTORNEY g 9 w. G. H. FINCH MULTISTYLUS FACSIMILE RECORDER .7 Sheets-Sheet 4 Original Filed Nov. 16, 1938 W w M a v WM a W m z 6 a m "M w W y mi H6 o o 3, .7 Rm W W 5 w. 1 up in INVENTOR Wm 5. 9.$irw5 M m ATTORNEY Aug. 8, 1944. w. G. H. FINCH MULTISTYLUS FACSIMILE RECORDER Original Filed Nov. 16, 1938 '7 Sheets-Sheet 5 INVENTOR N 5. 1%. $4105 ATTORNEY.

1944- I w. G. H. FINCH MULTISTYLUS FACSIMILE RECORDER Original Filed Nov. 16, 1938 '7 Sheets-Sheet 6 INVENTOR saw-"M v ATTORNEYY Aug; 8, 1944. w. G. H. FlNCH 2,355,369

MULTISTYLUS FACSIMILE RECORDER Original Filed Nov. 16, 1938 7 Sheets-Sheet 7 INVENTOR ummwwwa ATTORNEY Patented Aug. 8 1944 MULTISTYLUS FAOSIMILE RECORDER William G. H. Finch, Newtown, Conn., assignor to Finch Telecommunications, Inc., Passaic, .N. J., a corporation of Delaware Original application November 16, 1938, Serial No.

240,675, now Patent No. 2,212,970, dated August 27, 1940. Divided and this application August 24, 1940, Serial No. 354,127

6 Claims.

This invention relates to facsimile systems, and more particularly relates to improvements in multi-stylus facsimile recorders. The present case is a division of my copending application Serial No. 240,675, filed November 16, 1938, entitled Multi-stylus facsimile recorder, patented Aug. 27, 1940, No. 2,212,970.

The present invention is directed to a multistylus facsimile recorder wherein individual styli are spacedly arranged on a common carrier or chain and moved into successive engagement with the recording sheet. Recording on the record sheet occurs during substantially the whole period of each scanning cycle. The styli engage the sheet successivelyto effect a substantially continuous recording operation.

The present invention is directed to improvements in the construction of a multi-stylus re-. 'corder with a. view towards compactness and simplicity of arrangement and with fool-proof operatlon for quality high-speed recording. The unit is designed for direct viewing of the recording during its progress.

Through extensive experimentation I have found that the fine pointed styli of the prior art wore excessively on high-speed recording, particularly for electrochemical recording operation. In accordance with my present invention, I provide a stylus disk in the form of a thin wafer which effects a rolling contact with the recording sheet during recording and obviates excessive wear on a novel stylus assembly and simplified means for aligning and adjusting the styli of a multi-stylus recorder.

Still another object of my invention is to provide a novel stylus having a rolling contact action to minimize wearing thereof.

A further object of my invention is to provide novel automatic stylus cleansing mechanisms.

- Still a further object 01'' my invention is to provide a novel arrangement for maintaining the stylus carrier or chain drive taut.

A further object of my invention is to provide a floating stylus.

The essence of my development of my facsimile recorder development of which the present invention is an important part resides in the paper employed. My facsimile recorder operates on a dry record sheet as distinguished from wet and I semi-wet electrolytic recorders or the impact type the stylus. Another advantageof the stylus disk resides in the simplified arrangement for maintaining the stylus clean from accumulated gummy substance which would otherwise mar the quality of recording.

Another feature of my .present invention is to provide a floating stylus arrangement for multistylus recorders together with means for accurately guiding the floating stylus in the recording path. Such construction greatly simplifies any precautions and care as required for rigid alignment of prior multi-styli arrangements.

' The 'styli are arranged on a common. carrier recorder arrangements.

Another object of my invention is to provide of recorder in which by impact of the stylus, a record is made. In preparing such a sheet, it not only must be sufliciently conductive to pass currents at relatively low voltages, but must react to small currents of the order of milliamperes'" which cannot ignite the sheet. Moreover the sheet must be non-inflammable.

Accordingly, a further object of my invention is to provide a dry record sheet for recording at low current and voltage values.

Still another object of my invention is to pro vide a novel dry record sheet.

These and further objects of my present in vention will become apparent in the following description of a preferred embodiment thereof taken in connection .with the drawings, in which:

Figure 1 is a plan view with the cover removed of a preferred physical embodiment of the recorder of my present invention.

Figure 2'is an end view of the recorder.

Figure 3 is a front view of the recorder.

Figure4 is a vertical cross-sectional view taken along 4-4 of Figure 1 showing a stylus assembly in end view in correlation with the associated recorder element.

Figure 5 is a plan view of the 'stylusiassembly corresponding'to the view from 5-5 of Figure 4.

Figure 6 is a front view of the stylus assembly viewed from 86 of Figure 5.

Figure 7 is a verticalsectional view through the paper feed roller mechanism taken along '|-.-1 of Figure 1.

Figure 8 is a detailed illustration of the pawl and ratchet arrangement of the platen driven as along 99 of Figure 2 showing the cyclic synchronizing mechanism for the recorder.

Figure 10 is theend view corresponding to Ill-40 of Figure 1 showing the drive gear arrangement for the paper feed.

Figure 11 is an enlarged cross-sectional view of the stylus assembly taken along of Fi ure 5.

Figure 11a illustrates a modified form of stylus cleansing mechanism.

Figure 12 is a broken front view of the stylus guide wire arrangement;

Figure 13 is a sectional view taken along |3-| 3 of Figure 12 showing the stylus guide wire adjusting means.

Figure 14 is a cross-sectional view taken alon |4'|4 of Figure 12 through the stylus guide wire anchorage.

Figure 15 is a vertical cross-sectional view through the motivating mechanism for the recorder and associated synchronizing arrangement therefor.

Figure 16 is the horizontal view taken alon l6|5 of Figure 15' showing the cyclic synchronizing cam arrangement.

Figure 17 is a vertical cross-sectional view through the stylus chain mounting as taken along of Figure 3. V

Figure 18 is a cross-sectional view of the tail stock end of the paper pick-up roll mounting as taken along |8| 8 of Figure 1. s

Figure 19 is a cross-sectional view of the clutch end of the paper pick-up roll mounting as taken along |9|9 of Figure 1.

Figure 20 is 'a sectional view of the paper pickup roll as viewed from 20-25 in Figure 18.

Figure 21 is a perspective view, partially broken away, of the multi-stylus facsimile recorder of the present invention as mounted in a preferred cabinet structure.

Figure 22 is a perspective view of the multistylus facsimile recorder of the present invention mounted in combination with a broadcast radio receiver.

The recorder of the present invention is arranged for compactness and simplicity of construction and operation consistent with quality high-speed-recording. The recorder is designed for mounting in aportable cabinet of the type and size similar to a radio console cabinet, a suitcase, or similar article. The recorder arrangement is also designedfor directly viewing the recorded matter as the recording progresses.

The multi-stylus drive assembly is mounted on top of a cast-iron base 20 as seen in Figures 1, 2 and 3. An endless belt or sprocket chain 2| is used as a carrier for the individual .styli 22 and is driven by sprocket gear 23 cooperating with idler sprocket wheel 24. Each stylus 22 is mounted at equi-distant points on chain 2| at intervals substantially equal to the width of the recording sheet 25. Styli 22 are moved in a plane base 25, as seen in Figures 3 and 15, is responsive to received cyclic impulses and cooperates with the driven mechanism to establish a proper phase position for each stylus 22 at the beginning of the recording excursion. The cyclic synchronizing or phasing action will be further described in detail in connection with Figures 9, 15 and 16.

A spiral gear 32 is connected to the synchronized driven shaft I (Figure 15) which drives sprocket wheel 25.v Figure 2 illustrates pinion 33 meshing with spiral gear 22 for driving the paper sheet. Pinion 35 is secured to rod 54 at the other end of which is connected worm 85. Rod 23 is rotatably supported beneath recorder base 24. Rod is driven by worm 35 through worm gear I! (seen in Figure '7) meshing therewith. At the other end of rod 35 is another worm l4 cooperating with worm gear 38. Worm gear 35 is connected to feed roll 45 for driving the record sheet 25 in a manner to be further described in connection with Figure 7.

Figure 2 shows the supporting cabinet in notdash lines. The recorder base 25 is set into recesses at the top corners of the bottom section 4| of the cabinet. A removable cover 42 ilts onto the cabinet 4|. Figure 21 is a perspective view of the described cabinet arrangement. A transparent window 45 is set above the recording area in order to permit direct viewing of the recording as it is effected. The window 45 is of glass or a transparent plastic that is set into the top cover 42. A

. roll of sensitive paper 45 is mounted underneath parallel to the base 20 and individually and successively cooperate with the recording sheet once per revolution of the chain 2|.

An electric motor 25 is supported beneath recorder base 20 by bracket 21. Motor 26 is preferably of the non-synchronous type operable from an alterna ng or direct current p wer S pp Motor 25 is coupled to drive shaft 2l ithrougha worm and worm-gear arrangement enclosed in housing 29, and shown in section in Figure 15.

Flexible cable 35 is used to connect the motor shaft with the gearing arrangement. The synchronizing magnet 3| supported beneath recorder the recorder base 24 between brackets 45-46. The rear side 41 of the cabinet is hinged at 45 to permit the insertion of a new roll of recording paper without otherwise disassembling the recorder. Record sheet 25 passes from roll 45 through an opening 44 in the recorder base 21. Sheet 25 is then threaded under guide roll 49, around platen 55 over drive roll 40, and onto take-up roll 5| as seen in Figures 2 and 4.

A plurality of spaced rubber rollers 52 are arranged on a rod 52 to press record sheet 25 against feed roller 45 during the recording operation. Presser rod 52 is socketed in brackets 54. Brackets 54 are secured to the ends of rods 55 shown in dotted line in Figure 1. A spiral spring 55 is attached to each end of rod 55 to normally mechanically bias the presser rollers 52 towards feed roller 40. A lever 51 is provided and used when sheet 25 is threaded between the spring biased presser rollers 52 and feed roller 40. As seen in Figure 2, a cam or eccentrically positioned disk 58 is arranged on the axis of support of lever 51. Cam 58 coacts with a finger ill secured to rod 55. Rotation of handle 51 causes finger 50 to rotate rod 55 against the mechanical bias of springs 55 and thereby move pressure rollers 52 away from roller 40.

A knurled-hard rubber knob 5| is secured to the left end of, the shaft supporting feed roller 40 to facilitate manipulation of the record sheet. By twirling knob 6| feed roller 4| is independently driven and record sheet 25 may be advanced until all the recorded matter projects beyond the pressure rollers 52. The recording sheet is then torn at the region beyond the pressure rollers and the recorded matter is withdrawn from the facsimile unit by the removal of pick-up roll 5|. Pick-up roll 5| is removably supported by the drive shaft 52 and tail stock 52 as'will be further disclosed in more detail in connection with Figures 18 and A practical feature of my present invention ref and the maintenance of a uniform tension across I the recording region of a wide record sheet such as shown at 25. The free end 94 of the record sheet is-inserted in a slot 95 in the spool 98 of the pick-up roll as shown in Figure 20. Pick-up roll 5| is mounted for rotation between the frame uprights 6|-91 by drive plate 62 and tall stock 93. Drive plate 62 is connected with gear 69 through friction clutch 95-96 as seen in Figures 1 and 19. Gear 98 is coupled to gear by an intermediate idler gear 99 as seen in Figures 1 and 10. Gear 10 is connected to the shaft of positively driven feed roller 40. The gearing ratio between gear 10 and gear 69 is designed to overdrive pick-up roll 5| to maintain a constant tension in the record sheet 25 during the normal feeding operation of recording. IA frictional slip occurs at the over-driven feed roll 5| to keep sheet 25 taut, as will be described in further detail in connection with Figures 18 and 19.

Feed or drive roll 40 is motivated through worm gear 39 as heretofore-described in connection with Figures 1, 2 and 7. Figure 7 shows in section the connection between worm gear 39 and shaft 15. 7 Roller 40 is pinned to shaft I5. Shaft I5 is mounted in suitablebushings in uprights 91. Worm gear 39 is rotatably mounted on a shoulder 15 extending from shaft 15. A washer "I6 is pinned at the end of shoulder 15 abutting the outside end of the hub of gear 39 to keep the work gear in fixed axial position. A pawl I1 is mounted near the periphery of gear 39. A positive drive connection is effected between worm gear 39 and roller shaft 15 through the pawl 11 and associated ratchet I8. Ratchet I8 is pinned to shoulder I5. The surface of feed roll is metallic to afford a continuous electrical contact to the recording sheetfor electro-chemical recording action. The metallic portion of feed roll 40 is connected to ground or frame potential forming the opposite potential to that of the.

stylus assembly.

As seen in Figure 8, engagement of pawl and ratchet ||18 occurs when worm gear 39 rotates in a counterclockwise direction. A positive drive is thus effected between worm gear 39 and drive roller 40 in the proper counterclockwise direction during the continuous feeding of record 1 sheet 25 during recording thereon. When knob 6|, as seen in Figures 1 and 3, is manipulated to turn shaft 15 counterclockwise, i. e., in the sheet feeding direction, ratchet 18 slips with respect to pawl 'I'I permitting the feed roll 40 to be advanced independently of the continuous drive thereof through worm gear 39. Manual rotation of shaft I5 and roller 40 causes a correspondingrotation I of pick-up roll 5| through the gearing arrangements 9999'10 (Figure 1). Any recorded matter on sheet 25 may thus be manually advanced onto the pick-up. roll 5| for removal from the facsimile unit.

An important feature of my present invention is the arrangement for rigidly guiding each stylus successively in the recording position.

The whole mobile stylus assembly.

In the present embodiment, three individual stylus asrecord sheet 25 is at the potential of the frame or base of the unit which is at ground potential. The stylus assembly is insulated from the frame and is at the opposite potential.

In order to insure a rigid linear path for each stylus during the recording excursion, means are provided for maintaining link-belt 2| at a predetermined tension or tautness. Reference is now made to the left end of Figure 3 where means for maintaining the tension in link-belt 2| is shown. Post 8| carrying gear 24 extends from an adjustable member 92. Member 92 is secured to rods 83 and 94. Rods 83 and 94 are slidably mounted in brackets 95 and 96 to base 20. A spring 81 under compression is arranged to mechanically bias rod 83 and therefore member 92 to the left. The force of spring 81 is designed to keep the belt or chain ,2I properly taut for carrying the styli 22 successively in their recording path. Any temperature variation which would tend to expand or contract the belt 2| or any wear which may occur in the chain is automatically counteracted and compensated for b the continuous action of spring 91. A predetermined adjustment of tension belt carrier 2| is thus effected. IA. set screw 88 is arranged on the side of member 82 opposite that of the spring 81 and is used to hold member 82 further against spring 81 when it is desired to remove chain 2| from the associated sprocket wheel. As shown in the drawings. set screw 88 is clear of member 82 after the unit is adjusted, in order that biasing action of spring 91 may be effective on the chain 2 I.

Figure 17 is a cross-sectional view taken along I'II1 through the compensating mounting for gear 24. Gear 24 is shown secured to post or hub 8| of insulation material having a concentric bushing 89 rotatably mounted on rod 90. Rod 90 is pinned at 8| to adjustable member 92. Pin 92 secures member 82 to rod 93. Member 82 is secured with rod 94 by means of opposed set screws 93- 93. Set screws 93 provide variable po sitioning of member 82 with respect to rod 84. A slot 94 is made in base 20 to permit different positioning of supporting member 82 in maintaining the tension on chain 2 I.

Figure 5 .is an enlarged plan view of a stylus assembly 22 carried by link chain 2| coacting with record sheet 25. Figure 6 is an end view of the stylus assembly. Figure 11 is an enlarged cross-sectional view through the stylus assembly. A flat rail is horizontally mounted upon insulation block I00 parallel to the recording path. Longitudinal edges of rail are rounded to accommodate rollers |0I--I0| and I02 of each stylus assembly; Two notched rollers I0| are attached beneath the forward portion of the stylus assembly 22 for coacting with the front edge of rail 80. A conical roller I02 is centrally mounted beneath the rear portion of the frame I03 of each stylus. The inclined conical surface of roller I02 coacts with the rear edge of guide rail 80.

The horizontal alignment of the stylus frame or unit is effected by means of a set-screw I05 projecting through frame I03 thereof. At any rate, a hardened rounded bearing point is effected by the bottom of screw I05 for riding on the top surface of rail 80 together. Roller I02 is rotatably mounted on the post'l04 projecting beneath stylus frame I03. The bottom end I01 of post I04 is threaded to accommodate; a nut I08 used for exerting a pressure against-spring I06. Spring I06 mechanically biases conical roll I02 towards,

the stylus frame I03 and rail 80.

An important feature of my present invention resides in the improved stylus contacting and guiding arrangement for the multi-stylus continuous recorder. In extensive experimentation with prior known recording points for this type of recorder, I have found that using even the hardest contact points such as tungsten, molybdenum or other metals, undue wear took place when proper recording pressure and reasonable recording speed were used. Thestylus point of the prior art wore down so rapidly as to make the multi-stylus recorder impractical for commercial operation. In accordance with my present invention, I employ a rotatable disk contacting stylus. I have found that such a stylus overcomes the prior difliculties of rapid wearing away in operation. A thin stylus disk Ill is secured to a rotatable rod II2 by means of an integral hub III. The thickness of the stylus disk III is of the order of the thickness of the recording line employed in recording. Thus where'lOO contiguous lines per. inch are used, the thickness may be one hundredth of an inch or slightly more. The peripheral or contacting edge of the disk I II is rounded to effect the proper contacting width with the record sheet 25. The stylus disk H is made of a hard metal such as tungsten, molybdenum or other suitable metal or alloy. Hub II I may be machined integral with the disk III or brazed or otherwise secured with a wafer disk corresponding to thestylus Illi.

The stylus support rod I I2 is rotatably mounted in a frame II5 secured to the right end of rod H8 and forms the stylus head of the assembly. Rod H8 is mounted concentrically within sleeve III. Sleeve III is secured to block II. The pos tion of block IIB with respect to the frame ill of the stylus assembly is adjustable by means of slots therein coacting with screws IlO-I It, as seen in Figures 5 and 6. Block III is thus horizontaliy displaceable with respect to the stylus assembly and aflixed in positionjby bolts IIS. Block H8 carries with it the whole stylus head including the frame III thereof. The proper accurate alignment of each stylus wheel II. is thus readily adjustable after the unit is assembled in connection with the gauge 2" as shown in Figures 1 and 2 to be hereinafter'described.

An important feature of my present invention resides in providing a floating stylus, and guiding the floating stylus in its recordingp th. As clearly shown in the enlarged sectional view of Figure 11, shaft I I2 carrying the disk stylus I ll is freely mounted within the supporting head H5. The stylus shaft H2 is free to rotate and also free to move vertically since the ends of shaft 2 do not abut the end plates Ill. Plates IM-I I4 are fixed opposite the ends of stylus rod I I2 topermit insertion or removal thereof from head I II when required. r

The disk stylus is accordingly rigidly maintained in the proper scanning position but is free to rotate and may also be readily displaced vertically by an amount equal to several times the thickness of the stylus'disk. I provide an accurately arranged guide for the floating stylus by the two taut parallel wires ilk-HI. The guide wires Mil-Ill keep the stylus disk III in accurate position in the recording path. Wires Ii-HI also prevent any fluttering or parasitic movement of the stylus disk, insuring uniform, high quality, high speed recording.

An internally threaded cap I20 coacts with the externally threaded end I2I of sleeve III. A compression spring I22 is mounted within cap I20, pressing against rod I It. The pressure of stylus disk IlIi against record sheet is adjustable by means of threaded cap I2. and its action on compression spring I22 against rod III for the stylus head. A back stop I25 is attached to block III of the stylus assembly in front of the inside portion of stylus holder II5 to fix the outward position of the stylus head. A predetermined pressure of the stylus disk H0 is thus readily eifected for recording on sheet 25.

Each stylus assembly is secured to a section of link chain H by a rivet I23 embedded between stylus frame I03 and a reentrant elbow I24 thereof as seen in Figure 11. Vertical alignment of the stylus head frame I I5 effecting a corresponding horizontal arrangement of stylus wheel III is made through the opposed pair of set-screws I28I25 as seen in Figure 6. Set screws I" press against opposite sides of a portion of frame II! to properly align it.

tion I32 of block III.

Another important advantage of the disk stylus form III! is the simplified and improved method of l alntaining each stylus clean for successive recording operations. A considerable problem of prior multi-stylus recorders was that of maintaining the stylus point clean for successive recor ng operations. The use of electroche. .ical recording paper-such as mercurous oxide or titanium oxide coating on carbon black paper caused quick accumulation of a gummy substance on the prior stylus points. The gummy material caused blurring and smearing of the picture being reproduced. A self-cleansing stylus assembly is effected by mounting wiper blades Iii-III having fingers pressing against the rear surface of the stylus wheel III as seen in Figs. 5, 6, and 11.

Wiper blades Ill-III are secured to a melee- During the recording atcursion, the stylus disk III presses against the record sheet 25 causing the stylus disc I II to rotate. Rotation of the disc II. causes the fingers Ill-III to scrape the surface thereof and remove any tarry or gummy substance which may cause smearing or gumming of the record sheet. Wiper blades I" and III are preferably of springy material such as spring steel or phosphor bronze.

Figure 114 shows a modified form for a continuous automatic cleanser of the roller styli. A fluid reservoir 01 having a folded absorbent pad OI is arranged to coact with a portion of the roller stylus I II. Pad 0! may consist of felt and is held in coaction with the surface of the stylus III by set screws as shown, or other suitable means. The middle of pad 05 projects into a fluid contained within the reservoir 01. Felt pad I5 is maintained moist by the chemical fluid. A cap 9! on reservoir 91 is used for inserting additional fluid therein. The chemical fluid employed is any suitable one which will dissolve or soften substances which may accumulate on the styli III. The moist pad OI coacts with the stylus III as it rolls on the recording excursion, and maintains the stylus clean of gummy or other substances. Reservoir is secured to block III in a manner similar to the mounting of the wiper blades IIII3I already described. In order to maintain the floating action of disk III-the pad 55 ismade sufllciently soft, or the reservoir unit 91 may itself be resiliently mounted on block III as will be understood by those skilled in the art.

In order to insure accurate travel of the floating stylus wheels III in the recording path, I

provide a pair of guide wires I40 and HI. Wires I40 and I are arranged parallel to the recording path and spaced by a distance equal to the thickness of each recording disk IIO. Guide wires I40-I4I are held taut and close to the record sheet 25 to prevent any flutter or other irregularity in the motion of the stylus disks H and otherwise define their horizontal path. 1 have found the guide wire arrangement I40-I4I particularly useful for high speed recording operation, such as 100 to 200 lines per minute. 7

- Figure 12 is a plan view of the guide wire assembly showing anchor I42 for the wires secured to the left upright 61 of the frame. The tensioning posts I44 and I45 are fixed in block I43 mounted in the right upright 61. Blocks I42 and I43 are of insulation material to electrically isolate the conductive wires I40-I4I from the frame.

. Guide wires I40 and I are arranged adjacent the record sheet 25 at the recording region without contacting therewith. The metallic guide wires necessarily contact the stylus and are therefore of the same electrical potential as the stylus, which is opposite that of the recording sheet. Accordingly the guide wires are electrically clear of the frame, the recording sheet and other associated drive mechanism.

Figure 13 is a 'cross sectional view along I3-I3 of Figure 12 showing the preferred guide wire tensioning arrangement. lower wire I4I into its proper position on block I43. The right end of wire MI is secured to rod I45 within a hole I41 of post I43. Posts I44 and I45 are frictionally positioned in block I43. Tensioning adjustment 'of wire MI is effected by turning post I45 by passing a pin or wrench through hole I46 therein to rotate the rod. The

A slot I46 guides the tension guide wire I40 is adjusted by post I44 similarly to wire I. Figure 14 is a cross-sectional View through the anchorage block I42 taken along I4--I4.of Figure 12. Wires I40 and which is mountable by a pair of screws 2 in a predetermined position upon a recorder base 20 as shown in Figures 1 and 2. Gauge 2I0 comprises a lever 2I2pivoted at 2I3 thereon. The frames of the styli 22 are fastened close to their predetermined equi-distant positions along the carrier belt 2| by rivets as already described. Nevertheless, for proper recording, it is necessary to perfectly align the styli.

Manual adjustment and alignment of the styli disks H0 is performed as follows: The adjustment is entirely mechanical and no electrical currents are applied to the unit. Chain 2I- is moved until it is locked due to the engagement of the synchronizing lever I12 with the cam I65 as seen in Figure 9, when the driving means for sprocket wheel 23 is locked, preventing'the movement of the belt 2|. Lever 2I2 of the gauge 2I0 is positioned so that when it abuts one side of the stylus disk IIO as shown in Figure 1, the stylus would be in the proper recording position whenit engages the record sheet. Stylus disk I I0 is accordingly adjusted until it becomes tangent to-the inside surface of gauge lever 2I2. H

The shifting or adjustment of block H8 is effected by means of the adjusting screws I I3-I I6 1 passing'through the slotted block I I6 alreadYdeprocedure already described is performed for ac-- curately positioning the next stylus disk H0.

The same procedure is followed until the third.

stylus disk is properly aligned.

Figure 15 is a cross-sectional view taken through the mechanism for insuring synchronous driving of the recorder with the transmitter. This arrangement is essentially similar to that disclosed in my copending application Serial No. 165,448, referred to above. As there described,

cyclic synchronizing signals are received with the facsimile signals and caused to actuate the synchronizing magnet 3I. Worm I is mounted within housing 29 and is attached to the flexible shaft 30 continuously driven by motor 26 as viewed in Figure 3. Coacting worm gear I6I accordingly continuously drives central shaft 26 to which it is keyed. Roller thrust bearings I62 and I63 support shaft 28. A friction clutch I64-I66 is connected between continuously rotating shaft 20 and spiral gear 32. It will be recalled that gear 32 effects the driving of the drive roller 40 for feeding record sheet 25 as previously described in connection with Figure 2. Member I64 of the clutch is pinned to shaft 28. The coacting member I65 of the clutch is fastened to a. sleeve I66 concentric about the upper half' of shaft 28. Spiral gear 32 as well as a synchronizing cam I61 are secured to thisdriven sleeve I66. The hub. I68 of the linked chain drive wheel I23 1s made of insulation material and secured to the same driven sleeve I66. Sleeve I66 is supported by roller bearing I69 mounted in the frame.

A friction layer I10 between clutch blades I64 and I65 causes continuous driving of the belt 2I and sheet drive gear 32 as long as the recorder is in synchronous movement and the upper disk I65 is not arrested from rotation. Reference is herewith made to Figures 2 and 9 for an understanding of the operation of the upper clutch member I65 in conjunction with synchronizing magnet I3I. Armature I1I coacting with magnet 3I has an extending lever I12 cooperating with the peripheral surface of disk I65. A projection I13 of clutch disk I65 abuts projection I14 of lever I12 at the end of each recording excursion if the recorder is not in phase synchronism with the transmitter. When the cyclic synchronizing signal is received and magnet 3i is energized scribed in connection with Figures!) and 6. Block 7s thereby, armature H is attracted" thereto against Figure 16 illustrates the cyclic actuation of the synchronizing switch I16 by synchronizing cam I61 through a pin I11 set in the frame. Synchronizing switch I16 actuates synchronizing circuits not shown herewith but fully described in my copending application Serial No. 165,448 and .also in my Patent No. 2,047,863, which issued July 14, 1936. It is to be understood that the electrical transmission and receiver circuits, the

will be understood by those skilled in the art.

The present case is directed to the recorder per se and improvements therein.

The arrangement for maintaining the wide record sheet 25 taut during continuous feeding thereof has already been referred to in connection with the description of pick-up roll inconnection with Figures 1 and 10. Pick-up roll Si is geared for overdriving so that its rate of rotation would normally tend to be faster than that at which feed roll 40 motivates the sheet. I provide a friction clutch 55-95 within the driving connection for the pick-up roll 5| in order that a slip may occur therein. The overdrive and clutch slip permit a uniform and taut pick-up of the sheet 25 after recording despite the increase in diameter of the pick-up roll during operation.

Figures 18 and 19 are cross-sectional views through the right and left mountings respectively of the pick-up roll 5|. Figure 18 illustrates the tail stock 63 comprising the spring biased spindle I80 attached to knurled knob I8 I. Pointed spindle I80 presses against a cavity in the wooden core of the roll 5|.

Figure 19 is a cross-sectional view through the slip clutch drive of the pick-up roll 5|. As already described, gear 58 is driven directly from the feed roll gear l0 (Figure Gear 50 is mounted to freely rotate about shaftl55. Clutch members 95 and 96 have frictional surfaces contiguous with the corresponding sides of gear 55. Clutch member 05 is pinned .to shaft I85 by pin l85. Shaft l85 engages clutch member 95 through pin l8] affixed to the hub of member I95. Shaft I55 is axially slotted at I" in order that pin lll maybe slidable therein. A threaded nut I90 coacts with the threaded exterior of shaft I05. Spring i9l is placed between nut I00 and clutch member 95 to spring bias the clutch into engagement with the rotatably mounted gear 50. The opposite end of shaft I85 is secured to drive plate l52 engaging an end of the pick-up ro l 5l. Driving of gear accordingly drives pi s-up roll 5| through the clutch 95-46 biased to the gear. This driving arrangement permits slippage of the pick-up roll and keepsthe recording sheet 25 taut at the recording position.

Figure 21 is a perspective view of a table model of the facsimile recorder of my present invention with the cover partially broken away. The base 20 of the recorder is set into the top inside corners of the base II as already described in connection with Figure 2. The top cover 42 covers the remainder of the unit and contains the transparent pane 45 positioned for viewing the recording directly. A perforated opening 205 is placed-in one or more sides of the cabinet 4| to facilitate ventilation due to the heating of the contained motor or thelike. It will be noted that the recorder is horizontally disposed and permits a compact arrangement with the oblong cabinet 4|. The cover. of thecabinet is shallow and presents a pleasing appearance, yet serving the important function of permitting a direct view of the recording as it progresses.

Figure 22 is a perspective view of the recordin unit mounted at the top of a radio cabinet "I also housing a broadcast radio receiver. The loud speaker 202, control knobs 205. and the station indicator 204 are similar to those in ordinary broadcast receivers. However, the circuits used in receiving sound signals from the broadcast stations may be combined with the essential circuits for receiving the facsimile signals. The combined radio and facsimile circuits may be such as disclosed in my Patent No. 2,047,883. The changeover may be effected by simply flipping a manual switch 205 adjacent the facsimile recorder to convert the circuit from sound reproduction to facsimile reproduction. A hinged cover 205 is arranged to permit ready access and viewing of the recorder unit.

The recording sheet 25 is a dry sheet which has first been inpregnated with carbon as, for example, with the pulp during the manufacture of the sheet. This provides the necessary conductivity to the sheet.

One side of the sheet is now coated with a metal oxide such as titanium oxide (T101) suspended in a finely divided state in lacquer such as nitrocellulose. The lacquer acts .as a binder and bonds the metal oxide to the surface of the sheet.

This metal oxide makes one side of the sheet white and is discolored black by current flowing from the stylus to the opposite carbon surface, acting as the second contact.

It will be apparent that the metal oxide coating must be so chosen as to give high conductivity to the sheet and is responsive to small current flow to discolor and set of! the image being transmitted with suflicient contrast. Moreover, the coating must be non-inflammable, must be uniformly applied because small variations may effeet the conductivity of the layer, and must have a composition of the order of-emulsion compositions of films.

In order to increase the conductivity and to improve the white appearance of the paper, alumi- 'num powder is added in such quantities as are possible without making the deposited solution turn gray.

In addition to the aluminum powder, metallic salts such as cadmium iodide, potassium iodide, lithium iodide, nickel chloride and iron chloride which also increase conductivity and help make the sheet non-inflammable may be added. The

4 composition may, for example, be of the following proportions:

About three pounds of titanium oxide (110:) to a gallon of lacquer; four olmces of aluminum powder and two ounces of cadmium iodide or other similar salt. 4

The mix is then coated on to the carbon paper and dried to volatilize the solvents.

Although cellulose lacquer has been described as the binder, other binders such, for example, as.

' cellulosic ether of a dextrine, or casein binder may be employed.

The resulting product is a carbon sheet having one surface coated white and conducting'about ten milliamperes at about 300 volts to produce small black dots.

sheet pick-up roll, a shaft for driving said pickup roll, a gearing connection between said feeding mechanism and said shaft proportioned to over-drive said pick-up roll, and a friction clutch between said shaft and said gearing connection to permit slippage of said shaft whereby said record sheet is maintained taut during recording thereon. v

3. In a facsimile recorder, a record sheet in the form of a roll; mechanism for continuously feeding said sheet during recording periods; a continuous scanning means wiping over said sheet and for carrying picture current thereto; asheet pick-up roll for receiving the recorded sections of the sheet; means for-overdriving said pick-up roll for maintaining said sheet-at the recording point taut for producing a constant pressure be-- tween said scanning means and said sheet dur-,

ing recording; and means for permitting slippage of said pick-up roll for maintaining a predeterr mined taut condition of said sheet.

4. In a facsimile reco'rder, a record sheet in the form of a roll; mechanism for continuously feed- "ing said sheet during recording periods; a,con-

recorded sheet portions including supports for a sheet.

tinuous scanning means wiping over said sheet and for carrying picture current thereto; continuous scanning means comprising a continuous chain carrying said scanning mechanism; and

means whereby said chain maintains said scanning mechanism in a predetermined pressure contact condition with said recording sheet; a sheet pick-up roll for receiving the recorded sections of the sheet; means for overdriving said pick-up roll for maintaining said sheet at the recording point taut for producing a'constant pressure between said scanning means and said sheet during recording; and means for permitting slippage of said pick-up roll for maintaining a predetermined taut condition of said sheet.

5. In a facsimile recorder, a record sheet comprising a paper composition responsive to variations in the amplitude of electric currents i'or correspondingly discoloring the paper; mechanism for continuously feeding said sheet during recording periods; a continuous scanning means wiping over said sheet and for carrying picture current thereto; a sheet pick-up roll for receiving the recorded sections 01' the sheet; means for overdriving said pick-up roll for maintaining said sheet at the recording point taut for producing a constant pressure between said scanning means and said sheet during recording; and means for permitting slippage of said pick-up roll for maintaining a predetermined taut condition of said 6. In a facsimile recorder, a record sheet comprising a paper composition responsive to variations in the amplitude of electric currents for correspondingly discoloring the paper; mechanism for continuously feeding said sheet during recording periods; a continuous scanning means wiping over said sheet and for carrying picture current thereto; continuous scanning means comprising a continuous chain carrying said scanning mechanism; and means whereby said chain maintains said scanning mechanism in a predetermined pressure contact condition with said recording sheet; a sheetpick-up roll for receiving the recorded sections of the sheet; means foroverdrivingsaid pick-up roll for maintaining said sheet at the recording point taut for pro-.- I

ducing a constant pressure between said scanning means and said sheet during recording; and means i'or permitting slippage oi said pick-up roll for maintaining a predetermined taut condition of said sheet.

WILLIAM G. H. FINCH.

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