CA1149315A

CA1149315A - Printing and/or correcting device for printing machines

Info

Publication number: CA1149315A
Application number: CA000331553A
Authority: CA
Inventors: Remo Falconieri
Original assignee: Ing C Olivetti and C SpA
Current assignee: Telecom Italia SpA
Priority date: 1978-07-18
Filing date: 1979-07-10
Publication date: 1983-07-05
Also published as: JPH0377070B2; DE2929559C2; IT7868696A0; BR7904546A; GB2030076A; GB2057976A; DE2929559A1; JPS5537394A; AR227631A1; GB2062366A; GB2030076B; FR2435355A1; GB2058675A; GB2062366B; US4498792A; GB2058675B; JPS6320716B2; JPS63178073A; IT1160425B; FR2435355B1

Abstract

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 form of a sheet of limited thickness is provided with a cut out portion corresponding to the printing point, and with a guide in the form 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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The present invention relates to a printing and/or correcting device for printing machines, in particular 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 first 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 correcting device which can be used in printers in which the printing unit is very close to the platen. ~his is the case when the printing unit is for example made up by a character-bearing disc with flexible laminae.

A third aim of the invention is to provide a printing and/orcorrecting device, in which the foward 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 and correcting device for printing machines comprising a platen including a printing point;
a support structure for supporting a printing field and a correcting field and locating the correcting field beneath the printing field; means supporting said support structure to move the printing field and the correcting field from a rest position allowing the printing point to be seen to a printing position, locating the printing field in front of the ~1493~S
- la -printing point for the correcting of printed characters;
first and second electromagnetic actuators each actuatable from an inoperative state to an operative state, wherein each of said first and second electromagnetic actuators are movable through a substantially identical working stroke for moving the support structure to the printing and the correcting positionr respectively; spring means to hold the support structure in the rest position; and means selectively connecting each of said first and second electromagnetic actuators with said,support structure for converting the working stroke of said first elec-tromagnetic actuator to the movement of the support structure to the printing position in the inoperative state of the second electromagnetic actuator, wherein said connecting means comprise a connecting element of -said support structure and a cam member fulcrumed on said supporting means and cooperative with said connecting element for moving said support structure from the rest position to the printing position against the action of said spring means, and wherein said connecting element of the support structure releases said cam member in the correcting position of the support structure.

A preferred embodiment of the inVQntion is given in the description which follows which is provided by way of non-' 25 limiting example with reference to the attached drawing in which:

Figure 1 shows a first partial cross-section of a printing machine;
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` Figure 2 is a second partial cross-section of the machine shown in Figure l;

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Figure 3 is a partial plan vlew of the machine shown in Flgures 1 and 2;
Figure 4 is a partial front view of some parts shown ln Figure 3~
5. Flgure 5 i8 a side view glvlng detalls of some parts shown ln Figure l;
Figure 6 is a cross-section of some individual parts shown in Flgure 3;
Figure 7 is a front view of some individual parts shown in 10. Figure 6;
Flgure 8 ls a plan vlew partly ln~cross-section of some detall of Figure 6; and Figure 9 i8 a vlew partly in cross-section and from below Of 80me details of Figure 6.
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15. DESCRIPTION OF A PRE~ERRED EMBODIMENT
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~ PRINTING MEC~NISM
The printing device co~prises a platen 11 for the typing paper 12 (~igure 1) and a carriage 13 which can be moved transversely across the sheet of typing paper 12 along two guides 14 and 16. The 20. carriage 13 is slidable on guides 14 and 16 in the two directions, for exa~ple by means of a reversible electric tor, as described in our Italian Patent Specification No. 864,395. The carrlage 13 is made up by side ~ieces 17 and 18, and a baseplate 22. An electromagnet ~U 23 (Figure ~r), fixed to an upright 19, pivoting on the guide 16 25. 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 flxed to a flange 28 of a selector shaft 29 (FiguLe ~),by means of a releaseable connection which is described in our 30. Italian Patent Specification No. ~,016,552. The selector shaft 29 is rotatable by means of an electric motor 31 fixed to the upright 19.
The character-bearing disc 27 ls 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 positloning wedge 34 which ls designed to cooperate with a complementary notch in the end 26 (Figure3) 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 described in our Italian Patent Specification No. 986,534.

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PRINTING RIBBON MECHA~ISM

A frame 41 tFigure 3) is mounted on the carriage 13 and consists of two side plates 42, 43, a central plate 44, and a sleeve 46 by means of which frame 41 pivots on a shaft 47 of the carriage 13. A spring 48 normally keeps the frame 41 rotated in the anti-clockwise sense in Figure 2, arrested by means of a pin 49 (Figure 3) sliding in a slot 51 of a cam 52 of the carriage 13.
The cam 52 (Figure 5) is mounted on an eccentric 53 of the carriage 13 and, under the bias of a spring 54, is normally rotated in the clockwise sense and is arrested by means of a projection 56 against the end portion 57 of the plunger 58 of a s~lenoid 59 fixed to the carriage 13. The slot 51 is so shaped as to cooperate with the pin 49 when raising the printing ribbon to the printing point and is open at one side in order to allow the pin 49 to pass out from it when the ribbons are raised higher to bring the correcting ribbon to the printing point.
A cartridge 61 (Figure 2), for a typing ribbon 62 is substantially identical to that described in our U.S. Patent No. 4,010,839. The cartridge 61 is mounted on the frame 41 and is detachably held in position by a leaf spring 63 acted on by a tension spring 65, holding the cartridge against two shoulders 64 and 66 (Figure 3) which projects from the side plates 42 and 43 respectively.
The typing ribbon 62 can be of the non-reusable carbon type or correctable type or of the fabric type operating in a closed loop.
In each case a device 100 (Figures 3 and 6) provides for advance in one direction only of the typing ribbon 62, contained in the cartridge 61.
Device 100 comprises a cylindrical stator 102 constructed of a ferromag-netic material, for example sintered iron, fixed to a side 18 of the carriage 13. The stator 102 has fixed to it, by means of screws 103, an upper flange 104 and a lower flange 105 of a non-magnetic material, for example stainless steel, in which a shaft 107 is mounted, which is rotatable coaxially in the stator 102.
Inside the stator 102, which is designed in such a way as to have three pole pieces, 108, 109, 110 (Figure 8), a rotor 112 of ferromagnetic material is provided, which is rotatably mounted with respect to the shaft 107. The rotor 112 is shaped so that two flanges 114 and 1~5 are provided (Figure 6) which each have three pole pieces 116, 117 and 118 (Figure 8) which are associated with the pole ~D

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pieces 108, 109 and 110 respectively of stator 102. A winding 120 is provided between the two flanges 114 and 115 (Figure 6~, and this can be selectively enerqised ln or~er to produce magnetic flux between the pole pieces 108, 109 and 110 and the pole pieces 116, 117 and 118.
5. A disc 122 of plastics material (Figures 6 and 8) is fixed on to the flange 114 of the rotor 112 and has frontal teeth 123 for unidirectional transmi~sion of motlon.
A disc 125, also of plastics material, is fixed below the upper flange 104 of stator 102, and has surface teeth 126 whlch face 10. the teeth 123 of disc 122. The teeth 126 are also orientated so as to only allow transmission of motion in one sense only. A part 128 of plaatics material is interposed between the discs 122 and 125 and i8 provided wlth a central bush 130 which is fixed to the shaft 107 and a peripheral ring 131, which is inclined with respect to the 15. discs l22 and 125, and is connected to the central bush 130 by means of two radiating arms 132 and l34.
The peripheral ring 131 of part 128 has teeth formed on its lower portion 136, which normally engage with the teeth 123 of disc 122 and is also provided with teeth at its upper portion 137, 20. which are aiametrically opposed to teeth 136 and which normally engage with the teeth 126 of the disc 125.
A stud 140 (Figures 6 and 9), carrying a rubber bush 141, is fixed to the flange 115 of the rotor 112 and pro~ects from the stator 102 through a slot 142. A spring 144 is tensioned between a tongue j 25. 145 of the stator 102 and the stud 140 and maintains the rubber bush 141 against one wall 146 of the slot 142, thereby keeping the rotor 112 inthe rest position. The rubber bush 141 is movable between the wall 146 and'a wall 143 of the slot 142. The upper end portion of the shaft 107 is shaped in such a way that a cylindrical cavity 150 is 30. provided, as well as a transverse slit 151 and a through hole 159, which is orthogonal to the slit lSl (Figures 6 and 7). The slit 151 houses, in a sliding manner, a blade 155, which is designed to engage with a sleeve, which is not shown in the drawings but is substantially similar to that described in Italian Patent Application No. 70426-A/74 35. mentioned above for the cartridge 61 for the forward motion of the inked ribbon 62. The blade 155 has a longitudinal slot 156 carrying a pivot pin 157, which is housed in the hole 159 through the shaft 107, and has a lower spigot 158 which is housed with a certain amount of play in the cavity 150. A helical spring 160 normally urges the blade 155 40. upwardly.

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Operation of the devlce 100 descrlbed above is as follows.
In the rest position, the wlnding 120 i8 de-energised and rotor 112, acted on by spring 144 iB located $n a position where the pole pieces 116, 117 and 118 are ofi'set with re~pect to the pole pleces 108, 109 5. and 110 of the stator 102 ~igure 8). It will now be supposed that it $s deslred to automatically effect advance tion of the lnked rlbbon 62.
After each prlnt of a character, the winding 120 is energlzed in any known manner, for a predetermined period of time, for example 10. 25msec, so as to generate magnet$c flux between the rotor 112 and stator 102. Due to the effect of the magnetlc flux, the pole pieces 116, 117 and 118 of rotor 112 become displaced lnto alignment with he pole pleces 108, 109, 110 respectlvely of the stator 102, thus provid$ng f~r clockwise rotation of the rotor 112 with respect to the 15. stator 102. The extent of the rotation is determined by the rubber bush 141 (Figure 9) wh$ch comes lnto abutment against the wall 143 of the slot 142; the angle of rotation of rotor 112 is for example about 24.
Due to the orientation of the teeth 123 of disc 122, and the 20. teeth 126 of disc 125 (Figures 6 and 8), the part 128, and consequently shaft 107 also, are caused to rotate. As a result of this the sleeve, which is engaged by the blade 115, causes advance motion of the inked rlbbon 62.
The windlng 120 i5 then de-energlzed and spring 144 brings 25. the rotor 122 back to the rest position. During this rotation (in the anticlockwisesense in Figure 8), the shaft 107 is not forced to move since the orientation of the teeth 126 of the disc 125 prevent rotatl'on in the antl-clockwi~e sense of the part 128. Raising and lowering of cartridge 61 is followed by the blade 155, which is blased 30. by means of the spring 160.
A paper guide which is made up by an element 161 of flexible sheet metal (Figure 4) and by two parts 162 of transparent plastics material arranged at the sldes of the sheet metal part 161, is fixed to the carriage 13. The paper guide 161 comprises a leaf spring 163, 35. which is arranged vertically at the side of the point of printing, and i8 designed ~o as to guide the external portion of the typing ribbon 62 between the character~bearing disc 27 and the part 161. The parts 162 in plastics material are arranged below and above the sheet metal part 161 and are provided with wings 165 and 167 which prevent the ~,3~

paper g~ide from catching on the edges of the typing paper 12. The paper guide 161 of sheet ~etal is provided wlth a V-shaped notch 172 arranged ln front of the point of printing ln order to llmit the area of contact of the typing ribbon 62 and of a correction ribbon 181. A
5. V-shaped projecting part is arranged ad~acent to the V-shaped notch, and is aligned wlth the leaf sprlng 163 (as can be seen in Figure 4) in order to prevent contact between the typing ribbon 62 and the sheet, auring the correctlon operation. `!
A cover 164 for the electromagnet 23 providing striking is 10. fixed to the upright 19 and comprises a seml-circular shaped part 166 (Figure 4) which has the purpose of shielding and protecting the upper part of the character-bearing disc 27. The cover 164 further includes a housing for the electromagnet 23 whlch covers the space existing inside the cartridge so as to prevent extraneous objects from entering 15. between the character-bearing disc 27, platen 11 and electromagnet 23. The cover 164 includes two lateral guides 168 which are coplanar with the semicircular 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 the 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 character-bearing disc 27, motor 31 and electromagnet 23 from the print position to an inclined rest position, so that the character-bearing disc 27 can be changed after the cartridge 61 has been removed. In front of the paper finger 161, the cover 164 25. is provided with a wall 173, having a hollow portion 174, corresponding to the V-shaped notch 172, which protects the front part of disc 27 and allows passage of the striker arm 24.
Operation of the solenoid 59 is as follows. In each print cycle, the solenoid 59 (Figure 1~ is energized and the plunger 58 is raised and its end portion 57 causes the cam 52 to rotate in the anti-clockwise sense against the action of spring 54. The eccentric 53 with the slot 51 (Figure 5) raises the pin 49 and consequently the frame 41 as well, this being opposed by the action of spring 48 (Figure 2). The fxame 41 (Figure 1) rotates in the clockwise sense and raises the cartridge 61 in order to position the typing ribbon 62 in the corresponding position for print. When the solenoid 59 is de-energized, the springs 48 and 54 bring the frame 41 back to the rest position, ~nd the cartridge 61 and the ca~ 52 :s well. with the ,~ .
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cartridge 61 ln the rest position, the operator is able to read the characters which have been written corresponding to the line of print.
The particular shaping of slot Sl has the effect of preventing the frame 41 from belng raisea ~hen the solenoid 59 raises its plunger 58) 5. beyond the position of the polnt at whlch the character i8 being printed or oscillating about thls particular point. It is possible for the solenoid 59 to be kept in the energized state by means of a current which iB less than the initial current ln order to keep the frame 41 and ,l cartridge 61 in the raised position for repeated print cycles. ~¦
10. CORRECTING RIBBON MECHANISM
The correcting ribbon device comprises a feed spool 176 (Figure 3), which is rotatably mounted on a plate 177 of the side piece 42, and a take-up spool 178, which is rotatably mounted on a plate 179 of the side piece 43. A correcting ribbon 181, which may be of the 15. li~t-off type, or of the cover-up type, is guided between the two spools 176 and 178 by two ribbon guides 182, leaf spring 163 and by the semi-circular shaped por~ ons 166 of the cover 164, so as to ensure that the correcting ribbon 181 remains arranged below the typing ribbon 62 and parallel both to the ribbon 62 and to the platen 11. The shaped 1 `
20. portions 166 furthermore prevent interference between the disc 27 and the ribbon 181. ¦
A solenoid 184 (Figure 2), which acts as and has characteristics which are substantially identical to those of the solenoid 59, includes a plunger 186 having an end portion 187 against which a ~houlder 188 25. of frame 41 is normally held under the influence of the spring 48. A ¦
ratchet lever 191 pivots on a pivot pin 192 of 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 the take-up spool 178.
30. Operation of the correcting ribbon device is as follows. The solenoid 184 is energized, whereby the plunger 186 and the end portion 187 raise the shoulder 188, causing the frame 41 to rotate in the clock-wise sense against the action of the spring 48. The frame 41 consequently raises the cartridge 61, spools 176 and 178, typing ribbon 62 and 35. correcting ribbon 181, up to the point where the correcting ribbon 181 is located at the point of print. The typing ribbon 62 is consequently raised beyond its normal operating position. The two ribbons are still guided by the leaf spring 163 and the guide 168 which take the place of the shaped portions 166 when guiding the correcting ribbon 181.

During this raislng operation, the ratchet lever 191, pivoting on the pivot pin 192 fixed to the carriage 13, engages the ratchet wheel 196 via shoulder 193 and causes the take-up spool 178 to rotate in the antl-clockwi~e 6ense~ thus causing the correcting ribbon 181 to S. advance. When the solenold 184 i8 de-energlzed, the sprlng 48 brings the fra~e 41 together with cartridge 61 and spools 176 and 178 carrying the ribbons 62 and 181 back to the rest position.
Among possible dification, the raising of the frame 41 could be carried out in a different manner to that which has been 10. described. F~r example, one of the solenoids could provide for the raising of the frame 41 from the rest position up to a first print position, whilst the other electromagnet could provide for a subsequent raising of the frame to achieve the correcting position. However in the embodiment described, the solenoids have identical strokes but the 15. lift given by the solenoid 59 is reduced by the mechanism illustrated in Figure 5.
The leaf spring 163 and theguide 166 and/or 168 could be used in printers which differ from the one which has been described, but in which the distance between the printing element and the sheet 20. of paper ls as restricted as it is here. A typical example is printers using styli or wires. The necessary modifications to the spring 163 ana to guides 166 will be readily accessible to these skilledin the art..

Claims

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

1. A printing and correcting device for printing machines comprising a platen including a printing point;
a support structure for supporting a printing field and a correcting field and locating the correcting field beneath the printing field; means supporting said support structure to move the printing field and the correcting field from a rest position allowing the printing point to be seen to a printing position, locating the printing field in front of the printing point for the printing of characters and to a correcting position locating the correcting field in front of the printing point for the correcting of printed characters; first and second electromagnetic actuators each actuatable from an in-operative state to an operative state, wherein each of said first and second electromagnetic actuators are movable through a substantially identical working stroke for moving the support structure to the printing and the correcting position, respectively; spring means to hold the support structure in the rest position; and means selectively connecting each of said first and second electromagnetic actuators with said support structure for converting the working stroke of said first elec-tromagnetic actuator to the movement of the support structure to the printing position in the inoperative state of the second electromagnetic actuator, wherein said connecting means comprise a connecting element of said support structure and a cam member fulcrumed on said supporting means and cooperative with said connecting element for moving said support structure from the rest position to the printing position against the action of said spring means, and wherein said con-necting element of the support structure releases said cam member in the correcting position of the support structure.

2. A printing and correcting device according to claim 1, wherein said connecting means further comprise an arrest element cooperative with said connecting element for positively positioning the support structure in said printing position without ribbon oscillation with respect to the printing point during the operative state of said first electromagnetic actuator.

3. A device according to claim 2, wherein said arrest element is included on a slotted part of said cam member.

4. A device according to claim 1, wherein each of said first and second electromagnetic actuators comprises a plunger movable with a rectilinear stroke between said inoperative state and said operative state, wherein said support means comprise a shaft member rotatably supporting said cam member, and wherein said cam member comprises a shoulder cooperative with said plunger to rotate said cam member in response to the rectilinear stroke of said first electromagnetic actuator, a first cam surface cooperative with said connecting element for holding said support structure in the rest position and a second cam surface disposed above and adjacent to said first cam surface for positioning said support structure in the printing position in response to the rotation of said cam member.

5. A device according to claim 1, wherein the correcting field is advanced by a mechanism in response to only the movement of the support structure to the correcting position.

6. A device according to claim 1, wherein the support structure supports a cartridge for the printing field and spools for the correcting field.

7. A correcting device according to claim 1, wherein said printing machines comprise a printing unit of the type having a character-bearing disc with flexible laminae, and wherein said support structure maintains said printing and correcting fields between said disc and said platen.

8. A device according to claim 7, further comprising a screen member having two ribs designed to prevent contact of the printing and correcting fields with the laminae of said disc.

9. A device according to claim 7, wherein said actuating elecromagnets cause the fields to raise from a rest position in which the printed characters are visible to a working position in which the printing or deletion may be actuated, further comprising a guide part for maintaining said fields adjacent to the platen when said fields are raised by the support structure.

10. A device according to claim 9, further comprising a paper finger plate arrangement including a cut-out portion in front of the printing point and a projection adjacent to said cut-out portion and substantially aligned with said guide part for limiting the region of contact of said fields for deletion or for printing with a sheet of paper and for preventing contact of the printing ribbon with the sheet of paper during the correcting operation.

11. A device according to claim 7, further comprising a paper finger plate arrangement including a central metal portion of limited thickness and two transparent side portions provided with edges in order to facilitate reciprocal displacement between the printing point and the platen.

12. A device according to claim 1, further comprising a guide part for maintaining said fields adjacent to the platen when said fields are raised by said support structure and wherein said guide part comprises a lamina which is fixed onto the central metal portion of said paper finger plate arrangement.

13. A device according to claim 1, further comprising means actuatable for raising said support structure in a different manner through smaller and larger amounts to said printing position and said correcting position, in order to position said printing field or said correcting field, respectively, in front of said printing point, and an advancing mechanism for advancing the correcting field only in response to the raising of the support structure through said larger amount, thus avoiding any advancing of said correcting field in response to the raising of said support structure through said smaller amount, wherein said advancing mechanism comprises a spool supported by said support structure and rotatable for advancing the correcting field, a ratchet wheel rotatably connected with said spool, a guide member carried by said support structure, and a lever fulcrumed on said supporting means and guided by said guide member to reciprocate with respect to said support structure in response to the movement of said support structure, wherein said lever comprises a pawl inoperative on said ratchet wheel when the support structure is moving between the rest position and the printing position and wherein said pawl engages said ratchet wheel for an incremental rotation when said support structure is moving between the printing position and the correcting position in order to rotate said ratchet wheel only in response to the movement of said support structure between said printing position and said correcting position.