GB2097336A

GB2097336A - A typewriter

Info

Publication number: GB2097336A
Application number: GB8204311A
Authority: GB
Original assignee: Hermes Precisa International SA
Current assignee: Hermes Precisa International SA
Priority date: 1981-03-13
Filing date: 1982-02-15
Publication date: 1982-11-03
Also published as: JPS57160671A; FR2501590A1; DE3208892A1; CH641410A5; IT1145626B; IT8168689A0; SE8201558L

Abstract

The typewriter comprises a plurality of adjustment circuits connectable between the keys (5) of the keyboard and the printing mechanism. A selector circuit permits one of the adjustment circuits to be selected and connected, such circuit corresponding to a selected keyboard layout, as a result of action upon contact elements (12) which supply binary coded information to the selector circuit (11). The contact elements (12) are carried by the cover plate (6) of the keyboard overlay upon which the characters corresponding to the keys (5) are printed. These contact elements (12) are composed of contact bridges between pins (17) and a central pin (18) of a male plug (16) which co-operates with a female socket (13) connected to the selector circuit (1 1) when the plate (6) is placed in position. The keyboard layout of such a typewriter is modified by simply changing the cover plate (6), without there being any need for a technician to be employed therefor. <IMAGE>

Description

SPECIFICATION A typewriter Background of the Invention The present invention relates to a typewriter which may be adapted for a plurality of keyboard layouts, this typewriter comprising a printing device designed for the selective printing of characters from a set of characters, a keyboard formed from keys and from a cover plate having apertures for the keys, this plate bearing, in the vicinity of each key, the written character or characters or the written operation corresponding to the key in question, and a plurality of adjustment circuits for adjusting the keyboard to the printing device, each circuit defining one keyboard layout.

The layout for the keyboard of typewriters is selected in dependence upon the language in which they are intended to be used. In fact, a certain number of characters and accents, as well as the frequency of use of the characters, differ from one language to another, and the keyboard layout of typewriters is studied so as to facilitate typing in each language.

In previous typewriters, it was necessary to provide the layout for the keyboard during its assembly. It was a complicated task to modify the keyboard layout of these machines and a large number of parts needed to be changed.

The latest typewriters, which are to a large extent manufactured using electronic components, offer, by way of contrast, considerable facilities for changing the layout of the keyboard. These machines are provided with a plurality of adjustment circuits, each circuit corresponding to one particular keyboard layout, and all these circuits are combined in one single electronic component.

A selector circuit comprising a plurality of contacts permits one of the adjustment circuits to be selected and connected as a result of binarycoded information being supplied to the selector circuit by means of contactors.

The contactors are actuated at the end of the manufacturing process when the cover plate for the keyboard is placed in position.

It is a simple matter to change the keyboard, but a technician has to be employed therefor. In addition to changing the cover plate, it is also necessary to modify the layout of the contactors for the connection of the adjustment circuit corresponding to the new cover plate.

The object of the invention is to provide a typewriter where, to modify the keyboard, only the cover plate needs to be changed, without a technician being needed to modify the coding of the contactors of the selector circuit.

Summary of the Invention According to the present invention there is provided a typewriter which may be adapted for a plurality of keyboard layouts, the typewriter comprising: a printing device designed for the selective printing of characters from a set of characters; a keyboard formed from keys and from a a cover plate having apertures for the keys; this plate bearing, in the vicinity of each key, a written character or characters or an operation corresponding to the key in question; and a plurality of adjustment circuits for adapting the keyboard to the printing device, each circuit defining one keyboard layout; wherein the cover plate is provided with means for controlling the connection of the adjustment circuit which corresponds to a respective cover plate, this cover plate being selected from among a group of plates which are each associated with one of the adjustment circuits of the typewriter.

Brief Description of the Drawings The present invention will be described further, by way of example, with reference to the accompanying drawings, in which:~ Fig. 1 is a perspective view of a typewriter; Fig. 2 is part of the electronic circuit of the typewriter; and Fig. 3 is an enlarged, perspective view of a detail of the keyboard of the typewriter.

Detailed Description The typewriter shown in the drawing comprises a carriage 1 which is capable of moving along a platen 2. The carriage 1 is provided with a printing disc 3 which is usually actuated by a selector element and co-operates with a hammer (not shown). The printing disc 3 carries a set of characters formed from a combination of the characters of several different kinds of keyboards.

The whole unit, comprising the printing disc 3, the selector element and the hammer, form a printing mechanism M.l. which is controlled by the keyboard 4 by means of an adjustment circuit.

The keyboard 4 comprises keys 5 and a cover plate 6 having apertures 7 for the keys 5, each plate 6 bearing, in the vicinity of each key, the written character 8 or characters or the operation corresponding thereto.

As shown in Fig. 2, the adjustment circuit 9 forms part of an electronic circuit arrangement 10 comprising a plurality of adjustment circuits 9.

There may be a large number of these adjustment circuits, possibly up to 50, for example. A selector circuit 11 is connected to the circuit arrangement 10 comprising the adjustment circuits 9. The selector circuit 1 1 permits one of the circuits 9 of the circuit arrangement 10 to be selected and connected as a result of this particular circuit being defined by a binary-coded signal provided by contact elements 12. Six contact elements 12 are sufficient to identify the fifty adjustment circuits 9.

Fig. 3 shows one preferred embodiment of the control for the contact elements 1 2. A female socket 13 has seven terminals 14, 1 5 and is fixed to the frame of the typewriter, in the vicinity of one corner of the keyboard. This socket 1 3 comprises six terminals 14 which are connected to the selector circuit 11 and are distributed around a central supply terminal 15. The control for the selector circuit 11 is ensured because the central terminal 1 5 supplies one or a plurality of the peripheral terminals 14. The cover plate 6 is provided with a male plug 16 which corresponds to the female socket 13 and therefore comprises six pins 17 disposed around one central pin 18.

;'hue contact means 12 are composed-of a bridging of one or a plurality of pins 17 with the central pin 18. This bridging is achieved during the manufacture of the plate 6, in parallel with the written symbols for the characters of the keyboard. The adjustment circuit is therefore connected automatically when the cover plate 6 is placed in position on the frame of the typewriter.

For each type of typewriter, there is a group of cover plates 6 which each correspond to one of the adjustment circuits 9. To change the keyboard layout of such a typewriter, it is sufficient to replace the cover plate 6 by the one which corresponds to the new, selected keyboard layout, the new adjustment circuit being connected automatically.

As shown in Fig. 3, the plate 6 may be fixed to the frame of the typewriter by means of projections 19 which engage, with force fit, in corresponding bores 20 formed in the frame of the typewriter.

Numerous variants may be envisaged for the typewriter to which the invention relates. The contact elements 12 cou.d be composed of pins which are integrally connected to the plate and are each capable of producing an electrical contact between two strips mounted on the frame of the typewriter, or, in the case where these pins are made of an insulating material, they are each capable of breaking an electrical contact between two strips mounted on the frame of the typewriter.

One of the edges of the cover plate 6 could be fitted between six pairs of strips which are integrally connected to the frame, the contact means 12 thus being formed, and a conductive material could be applied to the edge of the plate at the places where an electrical contact has to be produced between their strips (i.e. strips of the contact means).

Claims

1. A typewriter which may be adapted for a plurality of keyboard layouts, the typewriter comprising: a printing device designed for the selective printing of characters from a sut of characters; a keyboard formed from keys and from a cover plate having apertures for the keys; this plate bearing, in the vicinity of each key, a written character or characters or an operation corresponding to the key in question; and a plurality of adjustment circuits for adapting the keyboard to the printing device, each circuit defining one keyboard layout; wherein the cover plate is provided with means for controlling the connection of the adjustment circuit which corresponds to a respective cover plate, this cover plate being selected from among a group of plates which are each associated with one of the adjustment circuits of the typewriter.

2. A typewriter according to claim 1, in which the control means are pins which are integrally connected to the cover plate and project from its lower surface, these pins co-operating with switches which are provided in the typewriter.

3. A typewriter according to claim 2, in which the pins co-operate with push-buttons of the switches.

4. A typewriter according to claim 2, in which the pins are made of an insuIa#ng material and are capable of breaking an electrical contact between two contactor strips.

5. A typewriter according to claim 2, in which the pins are conductors and are capable of producing an electrical contact between two contactor strips.

6. A typewriter according to claim 1, in which the control means are formed on one of the edges of the plate designed to fit between pairs of contact strips, this edge having portions of conductive material, each of these portions being capable of producing an electrical contact between two strips of a pair of contact strips.

7. A typewriter substantially as herein described with reference to and as illustrated in the accompanying drawings.