CA1201232A

CA1201232A - Telephone apparatus

Info

Publication number: CA1201232A
Application number: CA000413369A
Authority: CA
Inventors: Henry Sherman
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-10-14
Filing date: 1982-10-13
Publication date: 1986-02-25
Also published as: DK453382A; NO823299L; DE3264570D1; EP0074319B1; PT75657A; NO157838B; PT75657B; EP0074319A3; EP0074319A2; NO157838C

Abstract

ABSTRACT OF THE DISCLOSURE:

Telephone apparatus comprising a line make switch, and a handset including a microphone and an earphone for connection to a telephone network when the line switch is made, and a further apparatus for use in conjunction with the handset. The latter bears a first connector including electrical contacts connected with electrical components in the handset, the first connector providing electrical inter-connections within the handset when the latter is used alone, and providing selective interruptions in the interconnections and connection to further apparatus when mated with a second connector borne by the further apparatus.

Description

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The present invention relates to telephone apparatus and more particularly to a eompact telephone set.
The miniaturisation of electronic circuits enables telephone sets with more or less complex Eunctional possibilities to be made relatively eompaet.
It is possible to make a compact telephone eon-taining in a single easing all the circuits and components required for a telephone eonnection, and performing the functions both of a handset and the base on whieh the hand-set would normally be placed when the telephone set is not in use. However, when the telephone set is to be used with auxiliary devices, sueh as an automatic answering machine, a musical hold generator, a memory and automatic number ealling system for frequently ealled numbers, the telephone set must be permanently eonnec-ted to the auxiliary devices, and this makes the complete system relatively complex and cumbersome.
An ob~eet of the invention is to alleviate the above problem by providing a telephone handset of simple and light construetion which may be used alone or in com-bination with auxiliary apparatus while leaving a high degree of freedom of movement to the user, compatible with a cable connection from the handset to the telephone net-work.
The present invention provides telephone apparatus comprising a line make switch, and a handset including a microphone and an earphone for conneetion to a telephone network when said line switeh is made, and further apparatus for use in eonjunction with said handset, wherein said hand-set bears first eonneetor means including electrieal con-tacts connected with electrical components in said handset, sald first conneetor means providing electrical intereonnec-tions within said handset when said handset is used alone, and providing selective interruptions in said intereonnee-%3~

tions and connections to further apparatus when mated with second connector means borne by said further apparatus.
Other features and advantages OI the invention will appear from the following description, given by way of example with reference to the accompanying drawings, in which:
- Fig 1 is a perspective view of a telephone apparatus in accordance with the invention, comprising a telephone handset associated with a module containing auxiliary apparatus, such as a telephone answering system for example;
- Fig 2 is an outside plan view of the upper half casing of the handset of Fig I;
-- Fig 3 is an outside plan view of the lower half caslng of the handset of Fig l;
- Fig .is a schema-t:i.c diagram of electrical con-nections in an embodiment of the telephone set of Fig l;
- Figs 5 to 7 are schematic diagrams showing examples of the connections of auxiliary apparatus to the telephone set in accordance with the invention by plugging the handset into the module with which it is associated in Fig l;
- Fig 8 is a partial sectional view of a telephone handset in accordance with the invention associated with a module comprising acous-tic coupling with the set;
- Fig 9 is a partial sectional view of a telephone handset in accordance with the invention into which is plugged an integra-ted circuit board bearing a complementary circuit;
- Fig 10 is an overall perspective view of a tele-phone handset comprising another embodiment of keyboard for dialling numbers, Fig 11 is an exploded view of the keyboard of Fig 10;

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- Fig 12 is a section on the line III-III ox the keyboard of Fig 10;
- Figs 13 and 14 are details from Fig 12 showing a peripheral rib before and after ultrasonic welding;
- Fig 15 is a partial top view of a thermo-formed flexible film; and - Fig 16 is a section on the line VI-VI of Fiy 15.
The telephone apparatus shown in Fig I comprises essentially a handset I having the general shape oE a wide open V, and comprising an upper half casing 2 and a lower half casing 3 assembled together by screws, and between which is interposed a seal 4, which not only seals the casing I but also protects the casing against lateral shocks.
The top face of the upper half casing 2 comprises a window 5 of rec-tangular shape through which appears a number dial or keyboard 6 for signalling numbers to be called.
In the embodiment shown, this dial is of the so-called touch sensitive kind.
Adjacent to the window 5 and on the same side, the half-casing presents an opening 7 for a switch 8 for making or breaking the connection with the telephone line. An indicator light 9 is associated with -the switch to indicate the condition of the line connection.
It will bé seen that all the components on -the top face of the upper halE casing 2 are grouped in one branch of the V, the other branch serving as a hand grip for the hand-set. Advantageously, the dial and line switch are disposed in the part of the half casing furthest from the user, while the handgrip area is in the part closest to the user.
As shown in Fig 3, the lower face of the lower half casing 3 presents a first grill 10 formed facing the position of a microphone II in the handset and, at the opposite end of the casing, a second grill 12 formed facing an ear-phone. In the central part of the lower face, shown in Fig 3, a transverse slit 13 is provided which is designed to rece.ive an external male plug 14 of a multi-pin connector, the o-ther half of the connector comprising a corresponding female socket (not shown in Fig 3) disposed within the casing 1 behind the slit 13.
Advantageously, the complete se-t may include a wall mounted support comprising a projection whose shape corresponds with that of the slit 13; the handset is then fixed to its support by engaging the projec-tion in the slit 13 so as to plug the handse-t onto the support.
In the embodiment shown in Fig 1, the telephone handset is associated with a module 15 comprising a plurality of auxiliary components of which examples are described below, and presenting on its top face a recess 16 which receives the handset.
The recess 16 compri.ses a base 17 of open V shape, matching the shape o:E the handset 1, the plus 14 ox the connector projecting from the apex of the base 17. The recess 16 a]so comprises an elongate hook 18 extending along one end of the recess, the rounded shape of the hook 18 matching a corresponding rounded end of the handset 1 so as to receive and guide this end of the handset when it is placed in the recess, positioning the slit 13 of the handset opposite the plug 14 of the module 15. The recess 16 also comprises two sides 19 which provide lateral guidance for the handset and contribute to centering it on the plug 14.
It will be seen therefore that -the arrangement shown in Fig 1 enables the handset 1 to be replaced in a precise single movement ensuring automatically that the male plug is opposite the slit 13 in the handset. Returning to Fig 3, it will be seen that a flat recess 20 is formed round the slit 13, and the recess 20 is adapted to receive an integrated circuit card having a male plug which can cooper-ate with the female socket in the handset and providing, %~

for example, an amplifler for the partially deaf, a memory for calling frequently used numbers automa-tically, or a memory containing a key code which alone enables the use of the telephone, for example.
As described below, ln accordance with a preferred embodiment of the invention, the handset rnay include all the circuit componen-ts necessary for its operation. It is therefore an independen-t handset, usable withou-t any comple-mentary active components in the support. This is the case of the handset shown in Fig 1. However, since the handset can be used with auxiliary equipment, such as an automa-tic answering machine, a musical hold device, a memory for numbers to be called, for example, this auxiliary equipment can be grouped in the module 15 and can be connec-ted by placing the handset 1 in the recess 16 so that the plug l to which the equipment is connected, engages in the connector socket behind the slit 13 of the handset 1 and establishes the required connections.
In the embodiment illustrated, the handset 1 com-prises the dial or keyboard, which makes the handset autono-mous. However, it is possible to lighten the handset by transferring the dial or keyboard to the module 15. It is also possible to provide a telephone set without dial or keyboard, in which case it is only autonomous for receiving calls.
When the telephone handset is used with an inte-grated circuit plugged into the recess 20 in the lower half casing, it forms a complete free-standing table set by itself, without any additional module. According to a par-ticular feature of this embodiment of the invention, the handset has the dial or keyboard 6 and the line switch 8 on its top face, while the microphone and earphone are disposed at the bottom face. This arrangement makes use of the hand-set particularly practical, and especially enables it to be ~2~ 32 used when plugged in to -the module 15 since the dial or keyboard 6 and line switch 8 are then still exposed for use.
In the plugged in position, the keyboard 6 can be used as a keyboard for calculations, if it is provided with a certain number of extra keys, the body of the calculator being disposed in the module 15. The module may comprise a display window 22 connected with the calculator circuits.
The seal 4 disposed between the two half casings

2 and 3 protec-ts the handset against shocks, bu-t also pro-lo vides a degree of acoustic insulation which enables the telephone handset of this embodiment of the invention to be used with an acoustic receiver and transmitter provided in the recess 16 of the module 15 as shown in Fig 8.
The circuit diagram is illustrated schematically in E'ig 4. The circuit comprises mainly a line make connec-tion 25 connected -to the conductor 26 linking the handset with the telephone network. The l:ine make 25 :is also con-nected with a bell circuit 27, which in a preferred embodi-ment of the invention actua-tes the earphone or loudspeaker 28 of the set, and a line rectifier 29. The rectifier 29 is in turn connected to a matching circui-t 30 between the line and the loudspeaker 28 and a buffer amplifier 31 between the line and the microphone of the set. The line rectifier 29 is connected to a detector circuit 33 responsive to the ready/ out of order condition of the set. The detector 33 is connected to a management circuit 34, which in turn is connected to the dial or keyboard 6 by a firs-t line 35 for sending instructions to the keyboard 6 and by a second line 36 for receiving data from the keyboard. The management circuit 34 is also connected to a line switching circuit 37 for number signalling, connected with the line rectifier 29 and a supply circuit and oscillator 38. The dial or key-board 6 is connected with an a-ttenuator circuit 39 for attenuating audio frequency signals and which in turn is connected to the matching circuit 30 between the line and the loudspeaker 28. The circuit 30 is also connected to the amplifier 31~
The chain dotted line in Fig 4 indicates the sepa ration between the circuit components contained in the casing of the handset 1 and those contained in any support provided for this, if the handset is made in the simplified version. In -this case, only the circuits associated with the bell, the mouthpiece (microphone) and earphone are con-tained in the handset itself, -the rest of the circuit components being in its support, if it is desired to use it with a keyboard.
The circuit shown in Fig 4 also comprises a multi-polar connector socket 40 which is housed in the handset casing 1 facing the slit 13 and which cooperates wi-th -the male plug 14 on the module 15. Each contact of the connector 40 is connected to one or more conductors connected wi.th junctions between two components in the handse-t circuit shown in Fig 4, and whose operation can be modified by either connecting and disconnecting the two components or by insert-ing an auxiliary equipment between them.
In the present embodiment, the connector 40 com-prises twelve contacts or contact sets which are connected to twelve particular points in the circuit. The connector contacts are identified by letters a to 1.
For the sake of clarity, the connections between the components of the circuit are shown in heavy lines, while the connections from the junctions of two circuits and the plug contacts 40 are shown in Eine lines. The connec-tions between components and -the connections with the plug are shown by single lines; it will be understood however that, it required, the connections may in fact be multiple conduc-tors.
Due to the fact -that all -the points in -the circuits of the handset of this embodimen-t of the invention which may be used for the insertion of an auxiliary device are connected to the plug 40, prac-tically all the circuit com-ponents supplied by these points can be associated with external circuit components contained for example in the module 15 of Fig 1, by simply plugging the plug 14 into the socket 40. On the other hand, the connections thus made can be broken immediately when the handset is lifted and the plug 14 and socker 40 separated. The differenc compo-nents of the telephone handset circui-t can therefore be reemployed in set ups which otherwise require the addition of equivalent components specific to the particular set-up.
This factor can lead to a substantial cost saving in the provision of auxiliary equipment for the telephone set.
In the embodiment shown in Fig,4, the con-tacts a to 1 oE -the connec-tor 40 are connected to junctions in the circuit according to the following lis-t:
a : bell circuit 27 b line connection 25 -_ : line rectifier 29 - detector circuit 33 d : management circuit 34 - detector circuit 33 e and f : amplifier 31 - microphone 32 g and : matching circuit 30 - loudspeaker (earphone 28) 1 : attenuator 39 - keyboard 6 : management circuit 34 - supply 38 k : keyboard 6 - management circuit 34 1 : management circuit 34 - switch circuit 37.
The schematic diagram in Fig 5 shows an example of the insertion into the circuit of Fig 4 of a memory con-tain-ing frequently called numbers. The line make 25 is perma-nently connected to the switch circuit 37 through the line rectifier 29. However, the switch circuit 37 is no-t connected with the management circuit 34 (as i-t is in Fig 4), but is connec-ted instead -through the supply circuit and oscillator 38 to a memory 41, the connections between the clrcuits 38 and 41 being established by the con-tacts of the plug 14 and the socket ~0. The memory 41 is also connected to the keyboard 6, again through the plug 14 and socket 40.
It will thexefore be seen that the memory 41 is substituted in this case for the management circuit 34.
The circuit as shown in Fig 6 illustra-tes how the handset may be plugged in-to a magnetic recorder. In this case, the line make 25 is connected as usual to the circuit 30 matching the earphone (loudspeaker) 28 -to the line, through the line rectifier 29, but the matching circuit 30 is also connected to a magnetic recorder 42 by inserting the recorder into the circui-t when the plug 14 is plugged into the socket 40.
The c:ircuit as shown in Fig 7 illus-trates the insertion into the ci.rcuit of a sound generator which, like the memory of Fig 5 and the magnetic recorder of Fig 6, may be contained in the module 15 associated with the handset (Fig 1). Irl this set-up, the line make 25 is connected to the buffer amplifier 31 between the microphone 32 and the line, through the line rectifier 29, and the amplifier 31 is connected to a generator of sound signals 43, the insertion of the generator 43 providing audible music during line hold when the plug 14 is plugged into the socket 40.
The circuit of Fig 4 enables the earphone (loud-speaker) 28 to be utilised not only to transmit conversation from the caller, but also to emit bell sounds. In order to obtain this function, -the junction between the matching circuit 30 and the earphone 28 is broken by plugging the plug 14 into the socket 40 while establishing a connection between the earphone 28 and the bell circuit 27. The ear-phone 28 is -then used to produce a ringing tone when the handset is plugged in, and as a normal earphone whsn the . g _ ~2~2~;~

handset is picked up. The indicator light 9 shown in Fig 1 is placed so as to be hidden by the buttom of the switch 8 when the swi-tch is closed, and is also used as a number indicator when the touch sensitive keys of the keyboard 6 are operated. To this end, it is connected to flash at the rhythm of the pulses transmitted to the l:ine by the keyboard.
The telephone circuit within the handset .L may also include means for storing the last number called, and a silence key which disables the microphone 32.
With the arrangemen-t described above, certain number of circuit components in -the diagram of Fig 4 can have multiple applications, either within the telephone set itself, or in conjunction with external modules. Thus, in the recess 20 of the bottom face of the handset lt can be inserted an amplifier for the partially deaf, a number ca].ling memory, or another sma].l peritelephone extra. also, as i.ndicated above, the socket ~0 and plug 14 form a connec-tor which can be used as an electronic code lock, and con-sequently provide selective user access -to certain functions, for example trunk calls, international calls, keyboard usage, or other special handset functions.
Concerning the applications of transmission of information between the telephone set and the module by means of audio frequency signals, the presence of the toric seal 4, which seals the handset to its support when the handset is places thereon, improves sound transmission between the ear-phone and microphone of the telephone handset and any extra components which may be provided in the support. It is thus possible for example to provide an answering machine which is triggered by reception of the ringing sound and transmits by the microphone 32 of the circult of Fig 4 the reception of the reply being ensured through the earphone 28, without any electrical connection between these components of the handset and the associated elements of the module, apart from

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the normal line make of -the telephone set.
The set-up illustrated in Fig 8 comprises a tele-phone set similar to that of Fig 1, but with the module having the feature of being coupled acoustically with the handset.
To this end, the module 45 comprises a recess 46 for the handset casing, comprising a continuous rim 47 com-pletely encircling the handset and bearing a lip seal 46 extending inwards. The toric seal 4 trapped between the two half casings 2 and 3 of the handset 1 engage the lip seal 48 to provide acoustic insulation of the inside of the recess from the outside, when the handset is in position.
The rim 47 comprises an end 49 which projects in a hook shape -to aid positioning and guide the handset into the recess.
In the bottom oE the recess 46 in the module 45, besides a passage accommodatiny the male plug 50, two orifices 51 and 52 are provided opposite the positions of the grills :l0 and 12 of -the microphone and earphone of the handset respectively, and providing an acoustic coupling with a loudspeaker 53 of an automatic answering machine and a microphone 54 of a recorder (not shown) contained in the module 45.
The cooperation of seals 4 and 48 avoids acoustic losses to the outside and improves the acoustic coupling thus provided.
The acous-tic coupling between the handset and module is accompanied by an electrical connection through a multiconnector cimilar to that shown and described above, and whose male plug 50 is shown in Fig 8.
Fig 9 shows how a modular circuit 55, forming an amplifier for the partially deaf for example, in the form of an integrated circui-t plate provided with a male plug 56 is placed in the recess 20 of the telephone handset.

The circuit 55, in the case oE the amplifier, is -to be inserted between the matching circuit 30 and the ear-phone 28 of the circuit of Fig 4, the contacts 57 of the p]ug 56 cooperating with corresponding contacts 58 of a female socket 5g in the handset 1 connected suitably with -the earphone 28 and microphone 30 so that plugging in -the circuit 55 in-terposes it in the desired p]ace in the tele-phone handset circuit.
In the preferred embodiments described above, the female connectors are borne by the telephone handset and the male connectors by the associated modules. It will be appreciated that the opposite arrangement may be adopted.
In the embodiment shown in Fig 8, the telephone set is associated with a module comprising an answering machine and a recorder 8.
However, -the module reEerred -to may be a data processing module if this is provided with a recess for receiving the handset, similar to tha-t described above.
Fig 10 shows a telephone handset 101, comprising a keyboard 102, in accordance with the present invention.
As shown in Fig 11, the keyboard is disposed in a recess 103 formed in the casing 104 of the telephone handset 101.
It will be seen, in particular from Figs 11 and 12, that the keyboard of this embodiment of the invention com-prises a set of contacts 105, covered with a flexible film106. The set of contacts 105, which are commercially available, comprises essentially a rigid support 107 in which are buried the connector wires whose ends 108 project from the support 107 at its edge, and a flexible sheet 109 on which are fixed metal cups and their connections. The set of contacts 105 therefore present a flat, thin member with protrusions on its surface facing the cup con-tacts.
In accordance with this embodimen-t of the inven--tion, the bottom 110 of the recess 103 presents a closed %

peripheral rib 111 which projec-ts upwards and extends along the side walls of the recess. The rigid support 107 of the contact set 105 is sealed solidly to the rib 111 so as to provide a thin closed gap 112 Eorming a resonance chest.
The rigid support 107 is fixed onto the peripheral rib by ultrasonic welding; to this encl, the size of the recess is slightly bigger than the size of the rigid support 107 so as to leave a clearance between the support and the side walls of the recess 103, this clearance being necessary to enable the support 107 to vibrate during the ultrasonic welding operation. jigs 13 and 14 show the peripheral rib 111 before and after the ultrasonic welding operation; it will be seen that during this operation the rib 111 is squashed and joins with the support 107. To ensure a good seal for the annular zone 112, it is preferable to perform the welding operation in such d way -that -the rib 11] is substantially buried in the support 107 by the operation;
for example the ultrasonic welding may reduce the height of the rib by three quarters. According to one embodiment of the invention, the rib has an initial height of 0,4 mm which is reduced by 0,3 mm to leave a gap 112 whose mean height is 0,1 mm. In order that the ultrasonic weld be satisfac-torily produced, the materials of the recess 103 and the rigid support 107 should be of similar consistency.
The bottom 110 of the recess 103 also comprises an elongate lateral opening 113 formed be-tween one of the walls and the peripheral rib 1l1 and accommodating the passage of the ends ]08 oE the connec-tor wires of the con-tact set 105~
According to an important feature of this embodi-ment of the invention, after the contact set 105 is fixed in the recess 103, it is covered with a thermo-formed flexible film 106 which mates with and adheres to the flex-ible sheet supporting the metal contact cups, its edges .a.wv~L~Oa~

being fixed to a shoulder 114 formed in -the side walls of the recess 103. In this way, not only is the recess 103 closed sealingly, which is important for -the protection of the circuits inside the casing, but also -the thermoformed flexible film 106 reinforces the flexible sheet support of the lamellas 109, and prevents them unsticking at the edges, since the film adheres solidly to the shoulders 114.
Fixing the thermoformed flexible film 106 onto the flexible sheet 109 supporting the contacts must be performed carefully to avoid inclusion of air between -them, since such an air inclusion can be a source of breakage of the film 106 after a large number of manipulations. Advan-tageously, the flexible thermoformed film 106 is fixed to the sheet support of the cups 109 and -the shoulders 114 by untrasonic welding.
Figs 15 and 16 illustrate the structure in a preEerred embodiment of the thermoformed flexible Eilm 106.
It comprises essentially a first thin top layer 115 of transparent material and a second protective layer 116 which is considerably thicker than the first layer 115. The markings of the different keys is obtained by printing on the underneath surface of the layer 115, that is to say the surface contacting -the layer 116, the printing being in negative. The inscriptions and decorations are printed first, that is to say the numbers and the circles round -them in the example illustrated; a second print of a background in a contrasting colour is then performed, still on the underneath surface of the layer 115. The two layers 115 and 116 are then put together.
The two layers 115 and 116 are preferably assem-bled with a layer of adhesive 118 between them.
When the two layers 115 and 116 are assembled, the next step is thermoforming to produce the protrusions at the contacts of the contact set 105, as shown in Fig 16.

The fact that the keyboard marking is produced by negative printing on the underside of the layer 115 gives durable .inscriptions, since -the printing :ink of the markings and background is not in contact with the fingers and is also protected by the layer 116. This techinque is consid-ered to offer considerably better results than the use of silk screening to obtain inscriptions on the flexible film 106.
The composition and thickness of the different layers 115, 116 and 113 are chosen to give a thin composite having sufficient elasticity to actuate the cup contacts, the ratio of the thicknesses of the layers 115 and 116 being for example 1 to 3~ In one embodimen-t of the invention, the top layer 115 comprises pol.ycarbonate 125 microns -thick and -the pro-tective layer 116 comprises a double adhesive layer such as an acrylic bond 0,3 Len thick, effective over a temperature range of -20C to ~120C con-tinuously, and temporarily up to 150C. The use of polycarbonate gives a contact film 106 which is pleasant to touch.
This embodiment -therefore gives a thin keyboard, a few millimetres thick for example, which combines the advantages of mechanical keyboards and of -touch sensitive keyboards. Thus users will find the feel and noises which they are used to with ordinary mechanical keyboards, but the size and agreeable appearance of the keyboard of this embodiment are characteristic of a touch sensitive type of keyboard.
Moreover, with this embodiment of the invention, xisk of premature fatigue failure of a metal cup keyboard is avoided.
The telephone set described above can be called a compact teleph.one; it is extremely handy and allows the user to move freely round the connection to the telephone line.
In addition extra functions can readily be provided simply 3~

by placing -the -telephone on a base containing one or more corresponding rnodules. In addition it provides a progressive telephone system, since the inltial handset can contain in its multipolar connector the connections required for future possible extensions by addition of furthe:r elements -to the external module it plugs intoO

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Telephone apparatus comprising a handset con-taining at least one microphone and a loudspeaker and carrying a circuit making and breaking switch for said apparatus, characterized in that said handset has one face thereof formed with a slit facing which is housed a first multiple connector having contacts electrically connected to at least some of a plurality of components located in said handset, said first multiple connector providing normal communication between the said components when said apparatus is used alone and cooperating with a complementary multiple connec-tor connected to circuits insertable in the circuit contain-ed in said handset by mating of said first connector with said complementary connector, sand handset further compris-ing an elongate casing whose general shape presents a widely concave face, said first connector means being dis-posed substantially at the middle of said concave face and said microphone and earphone being disposed at respective ends of said casing facing respective apertured zones in said concave face, said line make switch being a manually operable switch disposed in the outer face of said casing.

2. Telephone apparatus as claimed in claim 1, wherein said handset comprises number registering means disposed in said outer face of said casing towards one end thereof.

3. Telephone apparatus as claimed in claims 1 or 2, wherein said casing comprises first and second parts assembled together and an acoustic seal member disposed between said first and second parts, said further apparatus presenting an elongate recess for receiving said handset, acoustic seal means extending peripherally round said recess for cooperating with said handset, and acoustic coupling apertured zones disposed in the bottom of said recess towards opposite ends thereof for coupling said further apparatus acoustically with said microphone and earphone respectively.

4. Telephone apparatus as claimed in claim 1, wherein said apparatus further comprises a support for said handset, said support presenting at least one end projection and at least one side projection for cooperating with an end and a side of said handset whereby to guide said first connector means into mating relationship with said second connector means when said handset is placed on said support.

5 . Telephone apparatus as claimed in claim 1, wherein said handset presents a recess in said concave face, said further apparatus including a circuit module solid with said second connector means, whereby said circuit module may be disposed in said recess in said concave face and connected electrically and mechanically with said handset when said first and second connector means are mated together.

6. Telephone apparatus as claimed in claim 1, wherein said apparatus further includes a wall support, said handset presenting an elongate aperture juxtaposed with said first connector means, and said wall support presenting a projection for cooperating with said elongate aperture where-by to secure said handset to said wall support.

7. Telephone apparatus as claimed in claim 2, wherein said number registering means comprises a keyboard comprising a set of manually operable metal cup contacts, a rigid support member bearing a set of connection members, a flexible sheet juxtaposed with said support member and bear-ing said set of contacts, said set of contacts being dis-posed in a recess presenting a peripheral rib projecting from the bottom thereof, said support member being ultrasonically welded to said peripheral rib whereby to define with the bottom of the recess a substantially closed acoustically resonant chamber.

8. Telephone apparatus as claimed in claim 7, wherein said recess presents a peripheral shoulder generally aligned with said set of contacts, said contacts being covered by a flexible thermoformed film secured intimately and sealingly to said flexible sheet, the edges of said film being secured to said shoulder by ultrasonic welding.

9 . Telephone apparatus as claimed in claim 8 , wherein said thermoformed film comprises a first transparent layer, markings printed on the under-surface of said first layer, and a second protective layer bonded to the under-surface of said first layer, said first and second layers together conforming to the shape of said set of contacts on said flexible sheet.

10 . Telephone apparatus as claimed in any of claims 7 to 9 wherein said recess is of a size sufficient to leave a small clearance round said number registering means.

11 . Telephone apparatus as claimed in claim 9 , wherein said number registering means includes an adhesive layer disposed between said first and second layers whereby to secure said layers together.

12 . Telephone apparatus as claimed in claim 9, wherein said first layer comprises a polycarbonate material.

13. Telephone apparatus as claimed in claim 12, wherein said first layer is substantially three times as thick as said second layer.

14. A telephone unit comprising a case, a circuit including components and at least a microphone and a loudspeaker contained in said case, a switch connected to said circuit for selectively turning the circuit on and off, said case having a downwardly facing side defining a slot in the center thereof, a first mutli-contact connector which is mounted on said case and placed in facing relation to said slot and comprises contacts which are electrically connected to at least some of said components in said case, said first connec-tor providing a primary connection between said components when the unit is used alone and being cooperative with a second complementary multi-contact connector which may be plugged to said first connector and is connected to accessory circuits which are insertable in said circuit contained in the case by a plugging together of said first connector and said second connector, the microphone and the loudspeaker of said unit being disposed in said case adjacent a lower side of said case and respective grills being defined by said lower side of said case on each side of said slot in facing relation ot said microphone and loudspeaker.