GB2046668A

GB2046668A - A ribbon transport device for a typewriter or printer

Info

Publication number: GB2046668A
Application number: GB7929548A
Authority: GB
Original assignee: Triumph Werke Nuernberg AG
Current assignee: Triumph Werke Nuernberg AG
Priority date: 1979-04-14
Filing date: 1979-08-24
Publication date: 1980-11-19
Also published as: IT7926314A0; IT1124581B; FR2453729A1; DE2915334A1

Abstract

The device is for a typewriter or printer which prints alternate lines in different directions and comprises a rocker 6 carrying a drive pinion 20 which drives a drive coupling element 4 for driving a transport wheel 3 of a ribbon always in the same sense irrespective of the direction of printing. A frictional drive 14, 15 drives the drive pinion 20 and causes the rocker 6 to pivot so that the pinion 20 drives the coupling element 4 either directly or through an intermediate gear wheel 24 depending upon the direction of printing. <IMAGE>

Description

SPECIFICATION A ribbon transport device for a typewriter or printer This invention relates to a ribbon transport device for a typewriter or printer.

In order to save time typewriters or printers which type or print alternate lines in different directions, i.e. one line from left to right and the next line from right to left, controlled by memory, are being used increasingly. These machines save carriage return time, but if a ribbon is being used, it must be transported in the same direction irrespective of the direction of typing or printing, otherwise if the direction of transportation of the ribbon changes with the direction of typing or printing, only one part of the ribbon would be used.

The present invention, the scope of which is defined in the appended claims, includes a ribbon transport device for a typewriter or printer which types or prints alternate lines in different directions, comprising a rotatable coupling element for driving a transport wheel of a ribbon, a drive pinion which rotates in one sense when the typing or printing is in one direction and in the other sense when the typing or printing is in the opposite direction, and means for transmitting the drive from the drive pinion to the coupling element such that the coupling element is rotated in the same sense irrespective of the direction of typing or printing.

In order that the invention may be well understood, an embodiment thereof, which is given by way of example only, will now be described, reference being had to the accompanying drawings, in which: Fig. 1 is a front view of a ribbon transport device; Fig. 2 is a view of the device in the direction of the arrow A of Fig. 1; and Fig. 3 shows a detail of the device.

Referring to the drawings, a housing for a ribbon cassette 2 is mounted on a plate 1 of a printing carriage not otherwise shown. The cassette may be a so-called endless cassette. The cassette 2 has a transport wheel 3 for the ribbon which is driven with the aid of a coupling element 4. The transport wheel 3 may be rotated by hand with the aid of the handle element 5 projecting upwardly out of the cassette 2, in order to provide the ribbon with the necessary tension at the printing location. The printing head (not shown) may be of the needle type.

A A rocker 6 is pivotally mounted about a pin 7 on the underside of the plate 1. The rocker 6 has two arms 8 and 9. The arm 9 has a borehole 10 through which a pin 11 projects. The pin 11 is provided in the region of the borehole 10, with a noise-reducing sleeve 12, for example, a ring comprising rubber or a similar material. The pin 11 is adjustably mounted on the plate 1 with the aid of a threaded stud, the axis of which is offset from the axis of the pin 11, and a nut 13, and acts as a stop means for limiting the pivoted movement of the rocker.

The arm 8 of the rocker 6 has rotatably mounted thereon a cord or cable wheel 14, having a cord or cable 1 5 which is wound around the wheel 14 a few times. The two ends of the cord or cable 1 5 are fixed to side parts 16 and 17 of the machine frame. In order to keep the cord or cable 1 5 at the required tension to prevent it slipping on the wheel 14 a spring 1 8 is advantageously interposed between one of the side walls and the end of the cord or cable 1 5. As illustrated, the spring 1 8 is attached to the side waIl 17.The wheel 14 and cord or cable 1 5 form a friction drive which operates through relative movement of the carriage, on which the rocker 6 carrying the wheel 14 is mounted, and the machine frame, the wheel being rotated in one sense when the carriage moves in direction B and in the other sense when it moves in direction C.

A drive pinion 20 is arranged on axis 19 of the cord or cable wheel 1 4 for rotation with the cord or cable wheel 14 in either sense depending on whether the movement of the printing carriage is in the direction B or C. The pinion 20 engages with either a gear wheel 21 or 22 depending on the direction of movement B, C of the printing carriage.

In Figure 1 the pinion 20 is shown engaging the gear wheel 21 which is mounted coaxially with the coupling element 4 for rotation therewith. A further gear wheel 23 is mounted coaxially with the coupling element 4 for rotation therewith and is in constant engagement with gear wheel 24, which is mounted coaxially with the gear wheel 22 for rotation therewith.

When the printing carriage moves in the direction B, the friction arising between the cord or cable 1 5 and the rotating wheel 14 causes the rocker 6 to take up a first position in which the pinion 20 engages the gear wheel 21 as illustrated. Thus direct transmission of the rotary movement of the wheel 14 to the coupling element 4, which drives the transport wheel 3 of the cassette 2, takes place through pinion 20 and gear wheel 21. When switching the direction of movement of the printing carriage to the direction of arrow C, the wheel 1 4 is caused to rotate in the opposite sense and the resulting friction between the cord or cable 1 5 and the wheel 14 causes the rocker 6 to pivot to a second position so that the pinion moves out of engagement with the gear wheel 21 into engagement with gear wheel 22.

The transmission of the rotary movement of the wheel 14 to the coupling element 4 is now via gear wheel 24 which drives gear wheel 23. Since the transmission is via an intermediate gear wheel gear wheel 24 - the coupling element 4 is driven in the same sense as when pinion 20 engaged gear wheel 21 even though the wheel 14 and hence the pinion 20 rotates in the opposite sense to the sense in which it rotates when pinion 20 engages gear wheel 21. As the coupling element 4 is driven in the same sense irrespective of whether pinion 20 engages gear wheel 21 or gear wheel 22, the ribbon of the cassette is always transported in the same direction.

Thus, the described device makes it possible to transport the ribbon always in the same direction independently of the direction of the movement of the printing carriage.

The pin 11 with its noise-reducing ring 1 2 limits pivotal movement of the rocker 6. The mounting of the pin 11 on the plate 1 with the offset stud enables the position of the pin 11 and thus the effective engagement of pinion 20 with gear wheels 21 and 22 to be adjusted. The noise arising when the rocker 6 pivots is reduced by the resilient ring 12.

Whilst the illustrated device employs a friction drive comprising a wheel 14 and a cable or cord which is operative to pivot the rocker 6 as required and to drive the pinion 20, other friction drive arrangements are contemplated. For example, the friction drive could comprise a wheel mounted on the rocker and running along a rail or the like fixed to the machine frame.

Furthermore, whiist the illustrated device has been described in association with a ribbon cassette, it will be appreciated that the ribbon need not be provided in cassette form.

Claims

1. A ribbon transport device for a typewriter or printer which types or prints alternate lines in different directions, comprising a rotatable coupling element for driving a transport wheel of a ribbon, a drive pinion which rotates in one sense when the typing or printing is in one direction and in the other sense when the typing or printing is in the opposite direction, and means for transmitting the drive from the drive pinion to the coupling element such that the coupling element is rotated in the same sense irrespective of the direction of typing or printing.

2. A device as claimed in claim 1, wherein the drive pinion is mounted on a rocker which is pivoted between a first position for transmitting the drive from the pinion to the coupling element when the pinion is rotating in one sense and a second position for transmitting the drive from the pinion to the coupling element when the pinion is rotating in the other sense.

3. A device as claimed in claim 2, wherein in its first position the pinion is arranged to drive the coupling element directly and in its second position the pinion is arranged to drive the coupling element through an intermediate gear.

4. A device as claimed in claim 3, wherein, in its first position, the pinion engages a gear wheel coaxial with the coupling element, and, in its second position the pinion engages a gear wheel coaxial with said intermediate gear, which intermediate gear is in constant engagement with a further gear coaxial with the coupling element.

5. A device as claimed in claim 2, 3 or 4, including a friction drive for rotating the pinion, which friction drive operates through relative movement of a carriage of the typewriter or printer and the fixed frame thereof, said friction drive causing the pinion to be in its first position when the pinion is being rotated thereby in said one sense and causing the pinion to be in its second position when the pinion is being rotated thereby in said other sense.

6. A device as clamed in claim 5, wherein said rocker is mounted on said carriage for said pivotal movement and, wherein said friction drive comprises a wheel rotatably mounted on said rocker and a cord or cable wound around said wheel and having its ends fixed to said frame.

7. A device as claimed in claim 6, wherein the cord or cable is tensioned by a spring.

8. A device as claimed in any one of claims 2 to 7, wherein stop means are provided for limiting the pivotal movement of the rocker.

9. A device as claimed in claim 8, wherein said s.top means comprises a pin which projects through a hole in the rocker.

10. A device as claimed in 9, wherein the position of the pin is adjustable.

11. A device as claimed in claim 8, 9 or 10, wherein the pin is provided with a sleeve where it engages the rocker for reducing noise.

1 2. A ribbon transport device for a typewriter or printer which types or prints alternate lines in opposite directions comprising a rocker carrying a drive pinion which drives a coupling element for driving a transport wheel of a ribbon always in the same sense irrespective of the direction of typing or printing, and frictional drive means for the pinion arranged to cause the rocker to pivot so that the pinion drives the coupling element either directly or through an intermediate gear wheel depending upon the direction of typing or printing.

1 3. A ribbon transport device substantially as herein described with reference to the accompanying drawings.

11. A device as claimed in claim 10, wherein the pin is mounted by mounting means offset from the axis of the pin.

12. A device as claimed in claim 9, 10 or 11, wherein the pin is provided with a sleeve where it engages the rocker for reducing noise.

1 3. A rubber transport device for a typewriter or printer which types or prints alternate lines in different directions comprising a rocker carrying a drive pinion which drives a coupling element for driving a transport wheel of a ribbon always in the same sense irrespective of the direction of typing or printing, and frictional drive means for the pinion arranged to cause the rocker to pivot so that the pinion drives the coupling element either directly or through an intermediate gear wheel depending upon the direction of typing or printing.

1 4. A ribbon transport device substantially as herein described with reference to the accompanying drawings.

New claims or amendments to claims filed on 25 June 1980 Superseded claims 1 to 14 New or amended claims:

1. A ribbon transport device for a typewriter or printer which types or prints alternate lines in opposite directions, comprising a rotatable coupling element for driving a transport wheel or a ribbon; a drive pinion mounted to a rocker pivotably mounted to a movable carriage of a typewriter or printer such that the rocker and pinion are movable between a first position for transmitting drive from the pinion to the coupling element when the pinion is rotating in one sense when typing or printing is in one direction and a second position for transmitting drive from the pinion to the coupling element when the pinion is rotating in the other sense when typing or printing is in the other direction, the coupling element rotating in the same sense irrespective of the direction of printing.

2. A device as claimed in claim 1, wherein in its first position the pinion is arranged to drive the coupling element directly and in its second position the pinion is arranged to drive the coupling element through an intermediate gear.

3. A device as claimed in claim 2, wherein in its first position, the pinion engages a gear wheel coaxial with the coupling element, and, it its second position the pinion engages a gear wheel coaxial with said intermediate gear, which intermediate gear is in constant engagement with a further gear coaxial with the coupling element.

4. A device as claimed in any one of the preceding claims, including a friction drive for rotating the pinion, which friction drive operates through relative movement of a carriage of the typewriter or printer and the fixed frame thereof, said friction drive causing the pinion to be in its first position when the pinion is being rotated thereby in said one sense and causing the pinion to be in its second position when the pinion is being rotated thereby in said other sense.

5. A device as claimed in claim 4, wherein said friction drive comprises a wheel rotatably mounted on said rocker and a cord or cable wounc around said wheel and having its ends fixed to said frame.

6. A device as claimed in claim 5, wherein the cord or cable is tensioned by a spring.

7. A device as claimed in any one of the preceding claims, wherein stop means are provided for limiting the pivotal movement of the rocker.

8. A device as claimed in claim 7, wherein said stop means comprises a pin which projects through a hole in the rocker.

9. A device as claimed in 8, wherein the position of the pin is adjustable.

10. A device as claimed in claim 8 or 9, wherein the pin is mounted by mounting means offset from the axis of the pin.