GB2261852A

GB2261852A - Ink ribbon guide

Info

Publication number: GB2261852A
Application number: GB9224603A
Authority: GB
Inventors: Ulrich Buschmann; Dieter Beck
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1991-11-27
Filing date: 1992-11-24
Publication date: 1993-06-02
Also published as: DE4139504A1; JPH05254230A; GB9224603D0; ITMI922619A0; ITMI922619A1; FR2684043A1; IT1256395B; DE4139504C2

Abstract

A ribbon guide means for printers with a matrix print head (1) is described. The print head (1) has a print element guide (3) which faces the platen (2), but is spaced therefrom by a gap (5). A vertically extending shield (7) for the ribbon (8) is provided on the print head housing (4). The shield provides a sliding surface (6) on one side of the gap (5). The guide means includes a pivotable ramp section (10) which can be brought into an inclined position for introduction of a fresh ribbon into the gap and into a non-operative position in which it does not obstruct the view of an observer and hinged to the upper edge (9) of the shield (7). <IMAGE>

Description

- 1 1 1 --- 1 A RIBBON GUIDE MEANS FOR PRINTERS This invention relates to

ribbon guides for printers and, in particular, to a ribbon guide for a printer with a matrix Print head.

A serial matrix printer has a print head with selectively actuated print elements lying opposite a print counterhead. The record carrier lies on the print counter-head and a ribbon driven either continuously or step-bystep is moved in a ribbon guide between the print elements and the record carrier.

in one known form of such a printer, a ribbon mask is arranged between the ribbon cruide and the print counter-head, which mask bears in slightly resilient manner on the ribbon guide and is attached at one end to a record carrier guidance means. However, this arrangement serves essentially to provide improved guidance of the ribbon by means of the ribbon guide and the ribbon mask which hinder the transfer of ink onto the record carrier or onto another object. The known ribbon guide is furthermore intended to prevent the ribbon from being thrown off.

A ribbon guide for a printer, the printer having a print element guide which faces but is spaced by a gap from the print counter-head and a shield for the print ribbon provided on the print head housing, the shield providing a smooth surface on one side of the gap, in accordance with the invention, comprises a ramp section movable between an inclined, ribbon guiding, position and a non-operative position and located on an edge of the shield.

The arrangement facilitates the introduction of the ribbon, which runs more or less slackly between the inlet and outlet of a bar-shaped cassette, and at the same time makes it possible to look at the printing point at which the print head is printing once the ribbon has been inserted into the gap between the print counter-head or record carrier and wire guide.

The advantages obtained include, in particular, in addition to simplified introduction, the fact that the introduction aid can later be moved away in order to ensure

2 free viewing, without manual contact with the ribbon being necessary. Since the ribbon guide is located on the matrix print head, there is also the advantage of a negligible increase in weight and accordingly a low economic cost in order to achieve the desired result.

Preferably, provision is made for the ramp section to be pivotally mounted in the region of the edge of the shield by means of an articulation and for a locking element to be located on the inner surface of the ramp section. The ramp section can then be pivoted into an inclined position or into a fixed position which is moved out of the field of vision of the user.

Furthermore, it is advantageous for the locking element to be resiliently attached to the ramp section by a first end and for a second end thereof to be able to be engaged with other parts by snapping in. Such articulations can be produced easily and economically, especially if made of plastic.

The connection-to the print head is made such that the ramp section is secured by locking-in by means of a base part on the shield. The shield can readily be provided with corresponding openings into which the base part can be engaged, especially so again if it is made of plastic.

According to further advantageous features, provision is made for the articulation between the ramp section and the base part to consist of a f ilm hinge and f or the ramp section, articulation and base part to be made in one piece.

Suitably, the second end of the locking element is claw-shaped and can be engaged in a catch on the base part.

The invention will now be further described by way of example with reference to the drawing which shows a side view of a print head in the direction of movement of -the head.

A matrix print head 1, which is designed, for example, as a wire matrix print head, lies opposite a print 3 counter-head 2 and also elements of a paper guide 2a which are arranged above the print counter-head 2. The matrix print head 1 has a print element guide 3 lying immediately opposite the print counter-head, which guide 3 is located in a print head housing 4. Between the matrix print head 1 and the print counter-head 2 and paper guide 2a, there is a gap 5 into which not only the paper, i. e. a record carrier, but also the ribbon has to be introduced. On the matrix print head 1 there is provided a sliding surface 6 which is located on a special shield 7 of the matrix print head 1, the upper region of which is shown in section. A ribbon 8 is initially providGd above the upper edge 9 of the shield 7, and is shown in a position from which it is brought into the gap 5.

The introduction of the ribbon 8 is achieved by a ramp section 10 which has an inner surface 10a. On this inner surface loa there is formed an articulation 11 which in the illustrated embodiment consists of a film hinge 11a.

The ramp section 10 has on its side remote from the print counter-head 2 a locking element 12, the first end 12a of which is attached to the upper region of the ramp section. A base part 13, a region of which is shown in section, is provided on the shield 7. The base part 13 has recesses 14 in which the second end 12b of the locking element 12 can be engaged.

As is illustrated with dot-dash lines, the ramp section 10 can readily be brought out of the position shown in unbroken lines into the position shown with dot-dash lines by finger pressure. It can clearly be seen that if the ramp section 10 is in the inclined position thereof, the ribbon 8 can be introduced into the gap 5 without touching the user by means of the ribbon cassette housing. When the ramp section 10 is folded down by finger pressure to the inoperative position thereof, it disappears from the field of view of the user, so that the latter can easily look at other parts, such as the paper guide 2a.

Claims

L4 1. A ribbon guide for a printer, the printer having a print element guide which faces but is spaced by a gap from the print counter-head and a shield for the print ribbon provided on the print head housing, the shield providing a smooth surface on one side of the gap, the guide comprising a ramp section movable between an inclined, ribbon guiding, position and a non-operative position and located on an edge of the shield.
2. A ribbon guide as claimed in Claim 1, wherein the ramp section is pivotaliLy mounted in the region of the edge of the shield by an articulation.
3. A ribbon guide as claimed in Claim 2, wherein the articulation comprises a film hinge.
4. A ribbon guide as claimed M any preceding Claim, wherein the ramp section is attached by means of a base part on the shield.
5. A ribbon guide as claimed in Claim 4 when dependent on either Claim 2 or Claim 3, wherein the ramp section, the base part and the articulation therebetween are formed as a single piece.
6. A ribbon guide as claimed in any preceding Claim, wherein a locking element is located on an inner surface of the ramp section.
7. A ribbon guide as claimed in Claim 6, wherein the locking element is elongate and is resiliently attached to the ramp section by a first end thereof, the second, free, end thereof being able to be engaged to lock the ramp section in at least the inclined position thereof.
8. A ribbon guide as claimed in Claim 7 when dependent on either Claim 4 or Claim 5, wherein the second end of the locking element is claw-shaped and can be engaged in at least one catch on the base part.
9. A ribbon guide substantially as hereinbefore described and illustrated in the accompanying drawings.