TELEPHONE INSTRUMENT

Abstract: A telephone instrument has a housing constructed from a first section (1) and a second section (2), the first (1) and second (2) section being connected together to form a housing. The second section (2) comprises three identical first sub-sections (4,5,6) which are substantially rectangular in plan. The number of first sub-sections is dependent on the dimensions of the first section (1) which is formed in one piece. The first sub-sections (4,5,6) comprise a first part defining a regular array of apertures (22, Figure 2) suitable for locating an array of pushbuttons (8). The array of apertures (22) extends across the full width of the rectangle so that when two or more subsections are butted together a continuous regular array of apertures extends across the arrangement of first subsections. A cover plate (9) covers locations in which no pushbutton is provided, the cover plate being located by the apertures (22). The first sub-sections also comprise a second part defining a single aperture (14) which extends over a major portion of the second part. A further sub-assembly (11) is mounted in the aperture (14) in the second part of one or more first sub-sections.

Description: The invention relates to a telephone instrument having a housing constructed from a first section and a second section, the first and second section being connected together to form a housing, the second section comprising a plurality of identical first sub-sections which are substantially rectangular in plan, the number of first sub-sections being dependent on the dimensions of the first section which is formed in one piece. Telephone instruments are commonly constructed from a base section and a top section (base and top referring to a table top rather than wall mounted instrument). Typically the base section has items such as a tone caller mounted within it and the top section carries push buttons and perhaps a visual display and supports the handset. There is a trend towards adding further facilities to telephone instruments, such as visual displays, repertory diallers, loudspeaking or "hands free" operation, and data transmission. Thus a family of instruments which may have a selection of these facilities may be required. This brings the problem of how to allow for the different facilities to be provided in the most economic fashion. Clearly the different instruments will require different sized housings, dependent on the number and type of facilities provided. Since the housings of the instruments are normally plastics mouldings a variety of different mouldings are required. This greatly increases the tooling costs for a range of instruments, particularly since the various options offered tends to reduce the quantity of any individual instrument type required. A telephone instrument as set forth in the opening paragraph is disclosed in German Patent No. 1223889. The telephone instrument described is formed by a base section into which a plurality of modules can be plugged, the modules containing various functional arrangements which can be connected together to form a complete instrument e.g. handset module, dial module, and a module containing a recall button. In the arrangements shown in Figures 1 to 3 of the German Patent all the modules are different from one another. However the arrangement shown in Figure 4 contains two types of module which are duplicated. The telephone instrument disclosed in the German Patent goes some way towards solving the problems set out hereinbefore but still lacks flexibility since changes within a module cannot easily be carried out without affecting the overall appearance. Austrian Patent No. 297807 discloses a telephone instrument having a plurality of identical subsections each comprising a linear array of apertures for receiving pushbuttons. It is an object of the invention to enable the provision of a range of telephone instruments without unduly increasing the number of different mouldings required to form their housings. The invention provides a telephone instrument as set forth in the opening paragraph characterised in that the first sub-sections comprise a first part and a second part, the first part defining a regular two dimensional array of apertures suitable for locating an array of pushbuttons, the array of apertures extending across the full width of the rectangle so that when two or more subsections are butted together a continuous regular array of apertures extends across the arrangement of first subsections and a second part defining a single aperture which extends over a major portion of the second part, wherein a further sub-assembly is mounted in the aperture in the second part of one or more first sub-sections. When the first section and the subsections are formed as injection moulded plastics members this enables the use of a reduced number of different mouldings with a consequent reduction in tooling costs. The first section is typically a base section of the telephone instrument and is less complex in form than the second section. Hence although a different base moulding is required for each size of instrument the tooling required for the base moulding is not so expensive as that required for the top section. Further the top face of the instrument can present an appearance showing a complete block of buttons and if a pushbutton is not required in any position the appearance can be maintained merely by mounting a dummy button in that position. A cover plate may cover locations in which no pushbutton is provided, the cover plate being located by the apertures. Where a block of pushbuttons are not required a cover plate can be located by the apertures to give a finished decorative appearance to the telephone instrument. The sub-sections may be mounted on a single printed circuit board. The printed circuit board provides, for example conductive tracks for a rubber mat keypad, key decoding circuitry and driving circuits for display devices. The sub-sections may be snap fitted on the printed circuit board by means of barbs on the sub-section engaging with apertures provided in the printed circuit board. This provides a structure which is sufficiently rigid for assembly and maintainance operations. In the embodiments described hereinafter further printed circuit boards for telephone and/or data facilities may be located in the base section. The second section may comprise a further sub-section formed to locate a telephone handset. Such a sub-section may be used on a whole range of telephone instruments since most telephone instruments require a handset. Consequently the number of further sub-sections required will be such as to justify the production of a special mould for this sub-section. The sub-sections may be connected to the first section by means of screws to enable the two sections to be easily separated for maintainance. Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 shows an exploded, perspective view of a telephone instrument according to the invention, Figure 2 shows a plan view of a sub-section for a telephone instrument according to the invention, Figure 3 is a cross-sectional elevation of the sub-section shown in Figure 2 the section being taken on line A-A, Figure 4 is a plan view of an embodiment of a telephone instruments similar to that shown in Figure 1, Figure 5 is a plan view of a further embodiment of a telephone instrument according to the invention, and Figure 6 shows a handset sub-section suitable for use in a telephone instrument as shown in Figures 1, 4 or 5. Figure 1 shows an exploded perspective view of a telephone instrument according to the invention, the telephone instrument having a housing comprising a first section 1 in the form of a base section and a second section 2 in the form of a top section. The top section 2 is constructed from four sub-sections 3,4,5 and 6, sub-sections 4,5 and 6 being identical to each other. The sub-section 3 is different from the other sub-sections and is designed to locate a handset 7. The sub-sections 4,5 and 6 are shown in greater detail in Figures 2 and 3 and will be further described hereinafter. Depending on the facilities to be provided by the telephone instrument a greater or lesser number of the sub-sections 4, 5 and 6 are provided while only one sub-section 3 per instrument is used. It is, alternatively, possible to dispense with the sub-section 3 and mount the handset 7 on a hook switch projecting from the side of the base section 1. The sub-sections 4, 5 and 6 carry a selected arrangement of pushbuttons 8, and cover plates 9 and 10 which may be blank or may be provided with legends. A further sub-assembly 11 carrying pushbuttons 12 and a display device 13 is mounted on the sub-sections 4,5 and 6 by means of barbs 15 which engage with the apertures 14 in the sub-sections. The rear of the base section 1 is provided with a plurality of cut outs 18 through which cable entry may be effected. The cut outs may have plugs and/or sockets mounted in them or be covered by blanking plates depending on cable entry requirements. Telephone and data circuits and components may be mounted on printed circuit boards located by projections 19. Figure 2 shows a plan view of a sub-section 20 suitable for use as the sub-sections 4,5 and 6 of Figure 1. The sub-section 20 comprises a first part 21 defining a matrix of apertures 22 for locating an array of pushbuttons 23. In this instance the matrix of apertures 22 comprises four columns and five rows. These numbers are arbitary and may be changed depending on the application. As shown in Figure 2 the pushbuttons 23 are arranged to have a minimum spacing so that there is merely sufficient clearance between them to allow independent operation. When pushbuttons are not required in every position in the matrix of apertures cover plates 25, 26 are fitted to mask those apertures 22 where a pushbutton is not required and provide a finished surface to the top of the telephone instrument. The pushbuttons and cover plates may be blank or may carry legends which may be produced in any convenient fashion, for example printing or engraving. The first part 21 and a second part 31 are separated by a ridge 26 and two further ridges 27 and 28 are formed at each end of the sub-section and define the extents of the first part 21 and second part 31. The first part 21 is also provided with a number of display devices 30 which are located next to pushbutton positions adjacent to the ridges 26 and 27. The second part 31 of the sub-section 20 defines an aperture 32 which extends over a major portion of the second part 31. The aperture 32 is provided with four projections 33 for co-operation with spring barbs to locate a cover plate or additional sub-assembly in the aperture 32. The aperture 32 extends over the major portion of the second part to allow access to the underside of a sub-assembly, when provided, to enable electrical connection between the sub-assembly and a printed circuit board to be made without inconvenience. Figure 3 is a cross-sectional view of the sub-section on line A-A of Figure 2. The sub-section 20 is mounted on a printed circuit board 40 by means of barbs 41 which project through co-operating apertures (not shown) in the printed circuit board 40. The pushbutton tops 23 are located in the apertures 22 by means of plugs 42 which are a friction fit within the hollow stem 43 of the pushbutton tops 23 and which engage against shoulders 44 of the apertures 22 to prevent the pushbutton tops 23 being displaced from the apertures. The printed circuit board 40 is shown broken in the region of the plug 42 merely to enable the fitting of the pushbuttons to be clearly indicated and in practice the printed circuit board extends continuously. The plug 42 isbiassed against the shoulder 44 by means of an elastomeric dome 45 which includes a conductive pill which short circuits tracks on the printed circuit board when the pushbutton is depressed. Only one dome is shown for reasons of clarity but all operative pushbuttons are provided with such domes. The cover plate 24 is located by means of barbs 47 which engage behind the shoulders 44 of appropriate apertures 22. The cover plate 25 is, of course, located in the same manner. The pushbutton tops are square and have a flat surface which contains a depression 50 which extends over substantially half the top surface area. As can be seen from Figure 3 the pushbutton tops 23 can be mounted with the depression in different orientations the purpose of which will be described hereinafter. The display devices 30 comprise a surface mounted light emitting diode 46 and a light guide 30, for example a perspex rod, which is in contact with the light emitting surface of the diode 46 at one end and whose other end provides the visual display at the top surface of the instrument. The sub-section 20 is attached to the first or base section 1 by means of screws passing through bosses 16 and pillars 17 (Figure 1) in the base section into threaded inserts (not shown) located in the ridges 26 and 27 of the sub-sections 20. Various additional or alternative methods of connecting the base and top sections would be readily apparent to those skilled in the art. For example horizontally extending lugs could be formed on the ridge 28 which engage in slots provided in the rear of the base section. Alternatively adhesives could be used, particularly with simple instruments where a replacement rather than repair philosophy was employed. Figure 4 shows a plan view of a telephone instrument similar to that shown in Figure 1. The telephone instrument shown in Figure 4 comprises a handset 107 mounted in a handset sub-section 103 and three indentical sub-sections 104, 105 and 106 which carry a plurality of pushbuttons 108, a cover plate 110 having spaces 120 for writing addresses for repertory dialling or call transfer and indicator devices 121 for indicating the address operated by a pushbutton depression or of a received call, a blank cover plate 122, and a further sub-assembly 111 carrying further pushbuttons 112 and a display unit 113. The pushbuttons 108 are of the same form as the pushbuttons 23 and the two columns immediately to the left of the cover plate 110 have their tops turned through 180 degrees with respect to each other. This enables the addresses written on the cover plate to be spaced at half the spacing of the pushbuttons which relate to those addresses, the depressions 50 indicating the address associated with a particular pushbutton. A similar arrangement is used in the two columns to the right of the cover plate 110 for the sample purpose. The telephone instrument described with reference to Figure 4 may be assembled as illustrated in Figure 1 and use the sub-section as illustrated in Figures 2 and 3. Figure 5 shows a plan view of a telephone instrument having fewer facilities than that shown in Figure 4. The instrument shown in Figure 5 comprises a handset section 203 carrying a handset 207 and two identical sub-sections 204 and 205. The first sub-section 4 carries an array of pushbuttons 208 while the second sub-section carries a number of pushbuttons 208, a cover plate 210 which has spaces for addresses 220 and indicators 221 and a plain spacer 222. The telephone instrument shown in Figure 5 is constructed from the same sub-sections as that shown in Figure 4. Figure 6 shows a plan view of a handset sub-section suitable for use in the telephone instruments shown in Figures 1, 4 and 5. The handset sub-section 303 comprises a rectangular plate 304 provided with two recesses 305 and 306. The recesses 305 and 306 are spaced and dimensioned to receive the mouth and ear pieces of the telephone handset. The instruments shown are designed for desk top mounting and the handset is kept in position by gravity. However, if wall mounting was desired with the handset lying substantially vertically rather than horizontally this could be achieved by appropriate design of the shape of the mouth or ear piece and the recesses. The recess 305 is provided with an aperture 307 through which the hook switch projects so that it can be operated by replacing the handset on the sub-section. Clearly many alternative arrangements using the sub-section shown in Figures 2 and 3 can be constructed, the layout of the cover plates and pushbuttons being variable to give a desired asthetic effect and to provide access to the facilities provided. Thus by using a sub-section provided with a regular array of apertures for locating pushbuttons and by arranging the buttons of adjacent pushbuttons to cover the area between the adjacent apertures a finished appearance can be given to a telephone instrument while allowing many different options to be offered using the same top sub-section. Clearly where single isolated pushbuttons are not required for a particular instrument the cover plate for that location could be constructed to have the same appearance as a pushbutton top.

Claims: A telephone instrument having a housing constructed from a first section (1) and a second section (2), the first and second section being connected together to form a housing, the second section comprising a plurality of identical first sub-sections (4,5,6) which are substantially rectangular in plan, the number of first sub-sections being dependent on the dimensions of the first section which is formed in one piece, characterised in that the first sub-sections (4,5,6) comprise a first part (21) and a second part (31), the first part (21) defining a regular two dimensional array of apertures (22) suitable for locating an array of pushbuttons (23), the array of apertures (22) extending across the full width of the rectangle so that when two or more subsections are butted together a continuous regular array of apertures extends across the arrangement of first subsections, and the second part (31) defining a single aperture (14) which extends over a major portion of the second part, wherein a further sub-assembly (11) is mounted in the aperture (14) in the second part of one or more first sub-sections. A telephone instrument as claimed in Claim 1, in which an array of pushbuttons (23) is located in the apertures of the first part (21), the heads of the pushbuttons being so dimensioned that adjacent pushbutton heads cover the area between adjacent apertures allowing only a clearance between them sufficient to allow individual pushbuttons to be operated. A telephone instrument as claimed in Claim 1 or Claim 2, in which a cover plate (9) covers locations in which no pushbutton is provided, the cover plate being located by the apertures. A telephone instrument as claimed in any preceding claim, in which the first sub-sections (4,5,6) are mounted on a single printed circuit board (40). A telephone instrument as claimed in any preceding claim, in which the sub-assembly is a snap fit in the aperture(s). A telephone instrument as claimed in any preceding claim, in which the sub-sections are connected to the first section (1) by means of screws. A telephone instrument as claimed in any preceding claim, in which the second section additionally comprises a second sub-section (3) formed for locating a telephone handset (7). A telephone instrument as claimed in Claim 7, in which the second sub-section (3) is of substantially the same overall shape and size as the first sub-sections (4,5,6).

Inventors: GOATMAN, MICHAEL CHARLES
Applicants: N.V. PHILIPS' GLOEILAMPENFABRIEKEN, PHILIPS ELECTRONICS UK LIMITED
Application year: 1986
Main classification: H04M1
IPC codes: H04M1, H05K5