CA1157800A - Printing and/or correcting device for printing machines - Google Patents

Abstract

TITLE OF THE INVENTION
Printing and/or correcting device for printing machines.

INVENTOR
Remo Falconieri, residing at Str. per Cuceglio 10090 S. Giorgio Canavese (Turin) Italy ABSTRACT OF THE INVENTION
The printing and correcting device is applied to a daisywheel printer and comprises a frame supporting a cartridge for a typing ribbon and a correcting ribbon arranged below the typing ribbon. The frame is able to swing as the result of operation of an electromagnet, from a rest position provid-ing visibility of the print, to an intermediate position for printing the characters. A second electromanget raises the frame through a greater length of travel in order to posi-tion the correcting ribbon in front of the printing point.
A rotating electromagnet causes automatic unidirectional advance of the typing ribbon after each character has been printed. The correcting ribbon is wound between two spools and its motion is provided by means of a pawl which engages with a gear wheel for driving the spool only in the case where the path of travel of frame is greater than that which relates to positioning of the typing ribbon.
A paper finger in the from of a sheet of limited thickness is provided with acute out portion corresponding to the printing point, and with a guide in the from of a leaf spring for guiding the two ribbons adjacently to the typing paper when they are being raised and for preventing unwanted contact by these.

Description

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~ rhis applicat:ion is a division of our Canadian patent applica-tion No. 331,553 filed July 10, 1979.

The present invention relates to a printing and/or correcting device for printing machines, in parti-cular of the type having electronic control.

Printing and/or correcting devices for typewriters are already known, but these are generally somewhat slow in operation and complicated.

A ~irst aim of the present invention is to provide a device which is simple, fast and has great ease of use, in particular for printing machines of the electronic type.

A second aim of the invention is to provide a cor-recting device which can be used in printers in which the printing unit is very close to the platen. This is the case when the printing unit is for example made up b~ a character-bearing disc with flexibl~ laminae~

A third aim of the invention is to provide a print-ing and/or correcting device, in which the forward motion of the corresponding ribbon takes place in a simple, reliable manner using inexpensive means.

In accordance with the present invention, there is provided a printing device comprising a platen including a printing point, a character-bearing disc with flexible laminae, support means for supporting a portion of a print-ing ribbon and a correcting ribbon in front of the platen and holding said portions of printing ribbon and correcting ribbon substantiall~ coplanar therebetween, means raising said support means for raising said ribbon portions between ,~

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a region proviclincJ for visibility of said printing point and alicJnment with said printing point fixedly with respect to -the printing point ~or holcling an active surface of said ribbon porti.ons near to the printing point, a screen member designed to prevent contact of said portions of the printing and correcting ribbons with the :Laminae of said disc, a guide part for the ribbons, wherein said screen member comprises two ribs ad~acent to the periphery of said disc and wherein said portions of printiny ribbon an~ said correct~
ing ribbon are guided between sald guide part and said two ribs when said ribbons are raised by said support means in order to allow the flexible laminae of the disc to be dis-posed at a minimum distance from the platen.

A preferred embodiment of the invention is yiven 1.5 in the description which follows which is provided by way of non-limitiny example with reference to the attached drawi.ng in which:

Figure 1 shows a first partial cross-section of a printing machine;

20Figure 2 is a second partial cross-section of the machine shown in Figure l;

Figure 3 is a partial plan view of the machine shown in Figures 1 and 2;

Figure 4 is a partial front view of some parts 25shown in Figure 3;

Figure 5 is a side view giving details of some parts shown in Figure l;

Figure 6 is a cross-section of some individual parts shown in Figure 3;

30Figure 7 is a front view of some individual parts shown in Figure 6;

. 3 _ Figure 8 is a plan view partly in cross-sectior of some deta:i.l of Flgure 6; and Figure 9 i5 a view partly in cross-section and from below of some details of Fiyure 6.
PRINTING ME~HANISM
The printing device cornprises a platen 11 ~or the typiny paper 12 (Figure 1) and a carriage 13 which can be moved transversely across -the shee-t of typing paper 12 along two guides 14 and 16. The carriage 13 is slidable on guides 14 and 16 in the two dlrections, for example by means of a reversible electric motor, as descri.bed i.n our Italian Pakent Specification No. 864,395. The aarriage 13 is rnade up by side pieces 17 and 18 and a baseplate 22. An electromagnet 23 (Figure 3) fixed to an upriyht 19, pivot,ing on the guide 16 carries a striker bar 24 having a shaped end 26 which cooperates with a character-bearing disc 27~
The character-bearing disc 27 is made of plastics material and is fixed to a flange 28 of a selector shaft 29 (Figure 2) by means of a releasable, connect;.on which is described in our Italian Patent Specification No. 1,016,552.
The selector sha~t 29 is rotatable by means of an electric motor 31 fixed to the upright 19. The character-bearing disc 27 is of daisy-wheel type with flexible laminae 32 (Figure 4) carrying print characters 33. Each lamina 32, on the opposite face to that carrying the character 33 is provided with a fine positioning wedge 34 which is designed to cooperate with a complementary notch in the end 25 (Figure 3) of the striker bar 24.
Selection of the character to be printed 33 is carried out by means of the motor 31 in a known manner, for example as descrihed in our Italian Patent Specification No. 986,534.

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E'~INTING_~If.sBoN MEC~IA~I.CSM

~ frame ~l. (Eiyu-re 3) is moun~ed ~n the carria~Je 13 ana con~ist~
of two si~a plates ~2, ~3, a cent~a.L platQ ~, and a sl~eve ~6 b~ means o~ wh.ich Era~e ~1 pivots on a shaft ~7 of the carriacJe 13. A spriny ~8 normally keeps the Erame ~1 rota~ed in the antl-alockwise sense in Figllre 2, arrested hy means of a pin ~9 ~Fig~lre 3) sliding in a.slot 51 of a cc~n 52 oE -the carriage 13.
The cam 52 (FicJure S) is mounted on an eccentria S3 o~ the carriaye 13 and, under the bia$ oE a spring 54, is noxmally rotatcd 1~1 the clockwise sense and is arrested b~ means o~ a projeation 56 again~t the end portion 57 of the plunger 58 o~ a sole7l0id 59 fixed to ~he a~rr~age 13. I~he slot 51 is so shaped as to cooperate with the pin 49 when raising the printing ri~bon to the printing point and is open at one side in order to allow the pin ~3 to pass out :Erom ik when the ribbons ar~
raised higher to bring the correcting rlbbon to the printing point ~ cartrid~e 61 ~Eigure 2), for a t~ping ribbon 62 is subs~antial]y identical to t~at described lh our U.S. Patent No. 4,010,~39L The cartridge 61 is mountea on the frame 41 cmd is detachably held in position ;y a leaf spring 63 acted on by a tension spring 65, holding the cartridge against two shoulders 6~ and 66 ~Figure 3) ~7hich pxQ~ect~
rom the side plates 42 and 43 respectively.
The typincJ ribbon 62 can be o~ the non~reusable carbon type ox correctable type or of the fabric type operating in a closed loop.
In each case a device 100 tFigures 3 and 6) provides for advance in one direct.ion only oE the typing ribbon 62, contained in the cartridge 61 Device ioo comprises a cylindrical stator 102 constructed of a ~erromag-netic material, for example sintered iron, fixed to a side lB oE khe carriage 13. '~he stator 102 has fixed to it, by means of ~cr2ws 103, an upper *lange 104 and a lower flange 105 oE a non-magnetic material, for example stainless steel, in which a shaft la7 is motm-ked, which . . -is rotatable coaxially in the stator 102.
. ~nside the stakor 102, which is designec~ in such a way ras to have ;three pole pieces, lOB, 109, 110 (Figure 8), a rocor 112 o~
ferror~tagnetic ma~erial is providea, which is rotatably mounted wi:th 35 respect to ~he shaEt 107. r~he rotor 112 is shaped so that two ~langes 114.ana 115 are provided ~Fig~lre 6) which eaclt have three pole piecas 116, 117 a.ncl llB (Figure ~ ich are associated with t~te pole - .

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_ 5 _ plece3 108, 1~9 ;Ina 110 xesp~ct:Lvely of stclt~r 102. ~ winding 12~ is pxovided ~etw~Qn th~ tw~ flan~es 11~ and 115 (~igurH 6), and thi~ ~an be s~l~ctively energi5ed ln oraer to pro~uce magnetic flux b~tween the pole pieces 10~, 109 and 110 and the pole pleces ]16, 117 ana 11~.
5, A ~sc 122 o* plastics matexlal '(Figures 6 and 8) i5 æiXea on t~ the fl~nge 114 o~ thQ rotor 112 and has ~rontal teeth 123 Xor unldirectional transmLssion of motio~. , A disc 125, also oE pl~stics material, is ~ixed balow thQ
~pper flange 104 o~ 6tator 102, and ha~ sur~ce teeth 126 whl~h ~aae 10. t,he teath 123 of disc 122. t~he teeth :L26 are also orientate~ so as to only allow transmission of motion in one sense only. A park 12 oi` plastics matarial is int~rposea between the discs 122 and 125 and is provided wlth a central bush 130 whlch is ~ixed to the sha~t 107 antl a peripheral xing 131, which is inalined with respect to the 15. t~scs l22 and 125, and is connectetl to the central bush 130 by means of two radiatiny arms l32 and 134.
, The per~pheral ring 131 o~ paxt 128 has teeth formed on its lower portion 136, which nor~ally engage ~ith the teeth 123 o~
disc 122 and is also provided with ~'teeth at its upper portion 137, 20. which are aiametr~cally opposed to teeth 136 and which normally , engage with the teeth 126 of the disc 125.
~ stud 140 tPigures 6 ana 9), carryin~ a rubber bush 141, is fixed to tha flange 115 of the rotor 112 and projects fro~ the statox 102 through a slot 142. A s~ring 144 is tensionea between a tongue 25. 145 of the stator 102 and the stud 140 ana maintains the rubbex bush 141 against one wall 146 oE the slot 142, thereby keeping t~le rotox 112 in the rest position. ~he rubber bush 141 is movable between the wall 146 ana'a wall 1~3 of the slot 142. The upper end port~on o~ the shaft 107 is shap,ed in such a way that a cylindrical cavi~y lS0 is 30. providea, as ~ell as a ~ransverse slit 151 and a through hole 159, which is orthogonal to the slit 151 ~Figures 6 and 7). The slit 151 houses, in a sliaing manner, a blade 1S5, which is designed to engage' with a sleeve, which is not shown in the dxawings but is substantially similar to that described in Italian Patent ~pplication No~ 70426-A/74 35. mentioned above fox the cartridge 61 for the fon~ard motion of the ir~ed ribbon 62. The blade 155 has a longitudinal slot 156 carryin~ a pivot pin 157, which is housed in the hole 159 through the shaft 107, and has a lower spi~ot 158 which is housed with a cextain ~mount of play in the cavity 150. A helical sprin~ 160 ~oxmally urges the blade 155 40. upwardl~.

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Op~ration of the.devl~e l()O de5cribea abov~ i3 as ~ollo~
In the rest posltion, the win~lng 120 i~ de-energi~-ed and rotor 112, acted on by sprln~ l~g ls locats~l ~n a position where the pole pieces 116, 117 anl 11~ are vset with recpect to ~he pole piec~s 10~, lO9 5. ~nd llo o the st~tor 102 tFigure ~). It wlll now be ~up~osed ~h~t it is ae.sirea to autonatically effect advance motion of the inked rlbbon ~2.
~ bsr each print Df a character, ~he wind1ng 12~ is energized in any known ma-nner, ~or a predetel~nea period o time, for ~xa~ple 10~ 2~msec, so as to genera~e ~agnetic 1ux b0twecn th~ rotor 112 and ~ator 102. .Due to the efect o the~ ma~ne-tia 1~x, the pole pieces 116, 117 and lla of rotor 112 become dlsplaced Lnto allyninent w:Lth he pole pieces 108, 109, 110 respectively o~ the ~tAt~r lO2, ~hu8 provid~ny *or cloc~w.Lse~ rotation o~ the rotor 112 with respec~ to ~he~
15. stator 102. The extent of the rotation is determined b~ the rubber bush l41 (~igure ~) which aomes into abutment agalnst the wall 143 oi the slot 142~ the angle of rokation oE rotox 112 is for example about 2~, -.
Due to ~he orien~ation of the teeth 123 vf disc 122, and the 20. teeth 126 o~ aisc 125 (Figures 6 and 8), the part 1~8, ana oonsequently shaft 107 also, ~re callsed to rotate. A5 a result o~ this the sleeve, which is engag&d by the blade 115, causes advance motion o~ the inked ribbon 62.
~he winding 120 is then de-snergi~ea and spring 1~4 brings 25. the rotor 122 bac~ to the rest position. During this rota~ion ~in the anti~clockwise sense in Figure 8), the shaft 107 is not ~orced to move slnce the orientation of the teeth 126 of ~he ~isc 125 pre~ent rotation in the anti-clockwise sense o~ the part 128. Raising and lowering o~ cartridge 61 is followed by the blada 155, which is biased 3~. by means of the spring 160.
A paper.guide which is made up by an ele~ent 161 o~ flex~ble sheet metal ~Fi~ure 4) and by two parts 162 oi transparent plastics material arranged at the sides of the sheet metal part 161, is fixea to the carriage 13. The paper.g~ude 161 co~prises a leaf spring 163V
35. which ls arranged vertically at the side of the point of printing, ana is designed so as to guide the external portion o~ the typing ribbon 62 between ~he characterw~earing disc 27 and the part 161~ The parts 162 in plastics material are arranged bel~w and above the sheet metal part 161 and are provided with wings 165 and 167 which prevent the . .

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pap~r guLde fro~n catchincJ on t~le eclyes of.the typincJ pap~ 12. q~he paper ~ude 161 oE she~t ~etal is provide~ with a V-shaPed notch 172 arranged ~n ~ront oE the point o* pxintlng in oraer to llmit, the area of cont~ct of'the typing ribbon 62 and of a correctlon ribbon 181. ~
5. V-shaped projectlny part is arrangecl ad~acent to the Y~shaped notch, and is alignea with the leaf spring 163' ~as can be seen in Figure 4) in ordex ~to prevent contact between the typin~ ribbon 62 and the ~heet, auring the correct~on operation.
A cover 164 for the electro~lacJnet 23 providing strlkLng is 10. fixea to the ~pright 19 and co~prises a semi-circu].ar shap~d par-t 166 ~Pigure ~) which has the purpose o~ shielcling and protectiny the upper part nf th~ character-bearlng disc 27. The cover 164 further includss a ho~sing for the electromaynet 23 which covers the space existing inside the cartridge so as to preven~ extraneo~ls objects ~rom enterin~
15. between the character-bearing disc 27, p:Laten 11 anA electro~agnet 23. The cover 164 includes two lateral guides 168 which are coplanar with the se~icirc~ar part 166, and which keep the typing ribbon.62 parallel to the platen 11, a shoulder 169 (Figure 3), which is designed to cooperate with ~he leaf spring 163 in order to keep the ribbon 62 .20. parallel to the character bearing disc 27 and finally a hand grip 171 (Figure 4), for rotating the ch~r~cter-bearing dlsc 27, motor 31 and electromagnet 23 ~rom the print position to an inclined rest position, so that the charac~er-bearing disc 27 can be changed a~ter the cartridga 61 has been removed. In front o* the paper finger 161, the cover 164 - 25. is provided with a wall 173, haYing a hollow portion 174, correspondingto the V~shaped notch 172, which pxotects the front part of disc 27 and al}ows passage of the striker arm 24.
Operation o* the solenoid 59 is as follo~qs. In each print cycle, the solenoid S9 ~FigUre 1) is energizea and the plunger 58 is 30. raised and its end portion 57 causes the cam 52 to rotate in the anti-clockwise sense against ~he action o~ spring 54. ~he eccentric 53 .
with the slot Sl (Fiyure 5) raises the pin 49 and conse~uently the frame 41 as well, ~his being op~osed by the action of spring 48 tFig~re 2). The *ra~e 41 tFigura 1~ rotates in the clockwise sense 35. and raises the car~ridge 61 in order to position the typing ribbon 62 in the corresponaing position for print, When the solenoid 59 is de-energized~ the springs 48 and 54 bxing the frame ~1 back to the rest position~ and the cartridge 61 and the cam 52 as well. With the ~ 3~

caitridy~ 61 in -~he rest poslt.ion, the operator 1.~ able to read the ch~racters which have been writ~en COrre.SponC~.riCJ to ths 117)e oE print~
The part1cular shaping o~ slot 51 has the effect of preventing the x~me 41 ~ro~ bein~ raised.~hen the solenoid 59 raises its plu~ger 58) 5. beyond the position of ~he point at whlch the character is belng printed or oscillating about this par-tlculax point. It is possible ~or .the solenoid S9 to be kept in the energized state by means o f a current which is l~.ss than the lnitial current in order to keep ~he ~rame 41 and cartridge ~1 in the raised positlon ~or repeated prink cycles.
10. CORRECTING RIBBON MECI-I~NISM
~ he coxrecting ribbon device comprises a feed ~pool 176 SFigure 3), which is rotatably mounted on a plate 177 of the sid~ piece 42, and a t~ake-up spool 178, whlch is rotatibly mounted on a plate 179 o~ the side piece 43. A coxrect.ing ribbon 1~1, which may be of the 15. lift-of t~pe, or of the cover-up type, is guided between the.two spools 176 and 178 b~ two r~bbon guiaes 182, leaf spring 163 and by ~he semi-circular shapea portions 166 of the cover 16~, so as to ensure that the correcting ribbon 181 remains arranged below the typing ribbon 62 ana parallel both to the ribbon 62 and to the platen 11. The shaped 20. portions 16~.~urther~ore prevent interference between the aisc 27 and the ribbon 181.
A solenoid 184 (Figure 21, which acts as and has characteristics which arè substantially identical to those o the solenoid 59, lncludes a plu;nger 186 having an end portion 187 against which a shoulder 188 25. o ira~e 41 is normally held under the influence of the spring 48.
ratchet lever 191 pivots on a pi~ot pin 192 o~ the carriage 13 and is guided by means of two shoulders 193 and 194 on the plate 179 in order to cooperate with a ratchet wheel 196 connected to ~he take-up spool 178.
30. Operation o the correcting ribbon device is as follows. ~he solenoid 184 ls energizea, whereby the plunger 186 and the end portion 187 raise the shoulder 188, causing the Erame 41 to rotate in the clock-.
wise sense ?gainst the action o~ the spring 48. The frame ~1 conse~uently raises the cartridge 61, spools 176 and l78, typing ribbon 62.ana 35. correcting ribbon 181, up to the point where the correcting ribbon lal is located at the point of print. The typing xibbon 62 is consequently raised beyona its n~rmal operating position. The tw~ ribbons are still guided by the ~.ea:E spring 163 and the guide 168 which take the place o the shaped portionS 166 ~hen guiding ~he correcting ribbon 181.

I~ri.~ 3 raisincJ op~rat::Lorl, the xa-tchet lever 191, pi~rOtincJ
on the pivot p:Ln 192 ~ixed t~ the carriage 13~ enya(Jes the r~tchet wheel 1~96 ~.a shoul~r 193 a~d cc~u3es the tc~e-up spool 17a to rotat~ tn the anti-clockw.Lse s~!nse, thus chusiny ~le coxrecklncl rlbbon 181 to . advance. When'the solenoid 1~4 is ae-enercJlzea, -the ~pring 4~
brintJs th~ i-rama ~1 together with cartridcJe 61 and spool.s 176 and 178 carr~ing the ribbons 62 and 181 back to the rest posltlon.
~ ong posslble ~o~ lcation, the ral3iny o the ~ra~e ~1 could be carried out'ln a di~erent m~mner to th~t whlch ~laS bee 10. descr~bea. ~x exc~ple, one o~ the so'Lenoids could provide iox the rais.ing o the i'rame ~1 irom the .rest posi~lon up to a fl~t prlnt position, whilst the o-ther electromagnet could provide ~:or a sub~equen~
raising o~ ~he .frame.to achie~e the correcting position. Howev~r in the el~o~i~ent described, the solenoids have identical str.okes but the 15. lift given b~ the solenoid 59 is reducea by the mechanlsm illustrated in Fi~uro 5.
The leaE spring 163 and thegui'de 166 and/or 16a could be used in pxintexs which dif~e~ from the one which has been de~cxibed, .
but in ~hic~'the d~stance between the printing ele~ent ~nd ~he sheet 20. of paper is as restricted as it is here. A t~pical example is printers using styli or wires. r~he nacessary modifications to the spring 163 ana ~o guides 166 will be readily accessible to these skilled in the axt..

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Claims (10)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A printing device comprising a platen including a printing point, a character-bearing disc with flexible laminae, support means for supporting a portion of a printing ribbon and a correc-ting ribbon in front of the platen and holding said portions of printing ribbon and correcting ribbon substantially coplanar therebetween, means raising said support means for raising said ribbon portions between a region providing for visibility of said printing point and alignment with said printing point fixedly with respect to the printing point for holding an active surface of said ribbon portions near to the printing point, a screen member designed to prevent contact of said portions of the printing and correcting ribbons with the laminae of said disc, a guide part for the ribbons, wherein said screen member comprises two ribs adja-cent to the periphery of said disc and wherein said portions of printing ribbon and said correcting ribbon are guided between said guid part and said two ribs when said ribbons are raised by said support means in order to allow the flexible laminae of the disc to be disposed at a minimum distance from the platen.

2. A device according to claim 1, wherein the screen member com-prises a semicircular shaped part with a semicylindrical rim which shields the upper part of the character-bearing disc and a shoulder for contacting a free end of said guide part.

3. A device according to claim 1, wherein the printing device comprises a hammer for the striking of one of said laminae to the printing point, wherein the screen member comprises a hollow portion for said hammer and wherein said screen member further comprises a housing for an electromagnet driving said hammer.

4. A device according to claim 1, further comprising a paper finger plate for holding a sheet of paper adjacent to the platen, wherein said paper finger plate comprises a projection adjacent to the printing point and wherein said guide part comprises a lamina displaced from said projection to define a space wherein said ribbons are confined adjacent to the printing point.

5. A printing device according to claim 1, further comprising a carriage movable parallel to the platen and mounting said character-bearing disc and a paper finger plate arrangement in-cluding a plate of limited thickness adjacent to the platen and provided with a cut-out portion aligned with the printing point and a projection at one side of the cut-out portion and wherein said projection is mounted adjacent to the printing point in front of and aligned with said guide part for guiding the prin-ting ribbon and the correcting ribbon between said projection and said guide part adjacent to the platen while the ribbons are being moved between the region providing for visibility of the printing point and alignment with the printing point, without interfering with the printing element and a sheet of paper moun-ted on the platen.

6. A device according to claim 5, wherein the paper finger plate arrangement includes a central metal portion including said cut out and said projection and two transparent plastic side portions fixed to the metal portion.

7. A device according to claim 5, wherein the screen member further comprises a shoulder which cooperates with a free end of the guide part for keeping the guide part substantially parallel to the platen.

8. A device according to claim 5, wherein said guide part com-prises a small bar which is substantially vertical and shaped so as to be substantially parallel to the platen.

9. A device according to claim 5, wherein the guide part com-prises a lamina fixed to the metallic portion of the paper finger plate arrangement.

10. A device according to claim 5, wherein the guide part for the ribbons is fixed to the paper finger plate arrangement.