CA1168778A - Selecting keyboard unit, particularly for telephone systems - Google Patents
Selecting keyboard unit, particularly for telephone systemsInfo
- Publication number
- CA1168778A CA1168778A CA000376694A CA376694A CA1168778A CA 1168778 A CA1168778 A CA 1168778A CA 000376694 A CA000376694 A CA 000376694A CA 376694 A CA376694 A CA 376694A CA 1168778 A CA1168778 A CA 1168778A
- Authority
- CA
- Canada
- Prior art keywords
- contacts
- selecting
- keyboard unit
- slider plate
- contact
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/02—Constructional features of telephone sets
- H04M1/23—Construction or mounting of dials or of equivalent devices; Means for facilitating the use thereof
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Push-Button Switches (AREA)
- Telephone Set Structure (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A selecting keyboard unit, particularly but not exclusively for telephone systems. The keyboard unit com-prises a plurality of selecting keys which are guided in a housing and operable to actuate sets of encoding contacts.
The keyboard unit comprises permanent magnets which are secured to respective key stems which are displaceable along a path. Reed contacts are secured in the housing each near an end of a respective one of three paths of the key stems.
A selecting keyboard unit, particularly but not exclusively for telephone systems. The keyboard unit com-prises a plurality of selecting keys which are guided in a housing and operable to actuate sets of encoding contacts.
The keyboard unit comprises permanent magnets which are secured to respective key stems which are displaceable along a path. Reed contacts are secured in the housing each near an end of a respective one of three paths of the key stems.
Description
~ 16~77~
This invention relates to a selecting keyboard unit, particularly for telephone systems, comprising a plurality of selecting keys, which are guided in a housing and operable to actuate sets of encoding contacts.
In known selecting keyboard units, transverse bars are secured to the key stems and e:Ktend into profiled slots of cam bars, which in response to the operation of a given key are shifted to actuate sets of encoding contacts. By means of the profiled slots in the cam bars, the keys are interlocked in such a manner that a simultaneous operation of more than one key cannot result in a simultaneous closing of the associated sets of encoding contacts.
The known selecting keyboard units have the dis-advantage that the mechanical means for actuating the contacts are extremely complicated so that the assembly is difficult and the manufacture of the selecting keyboard unit is highly expensiveO
It is a feature of the present invention to provide a selecting keyboard unit which can be simplified considerably and permits the enabling of a talking circuit by a set of contacts which is similar to the sets of encoding contacts.
In a selecting keyboard unit of the kind described first hereinbefore that feature is accomplished in accordance with the invention by the provision of;permanent magnets secured to respective key stems and of reed contacts secured in the houslng near t'ne end of the paths of the respective key stems.
:
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~ 16~7~
Accord.ing to a fu:rther broad aspect of the present invention there 1s provided a selecting keyboard unit, partlcularly for telephone systems. The unit comprises a plurality of selecting keys which are guided in a housing and operable to actuate sets of enc~d~ng contacts. Permanent Inagnets are secured to respective key stems of the selecting keys and reed contacts are secured in the housing near the end of the paths of the respectlve key stems. The key board unit is characterized in that the reed contacts are secured to a common contact-carrying plate which i.s parallel to the keyboard and wherein the reed contacts are essentially diagonally oriented with respect to the cross-section of the housing.
- la -', '~
1 16877~
The reed contacts constitute the encoding contacts and because they are enclosed in glass tubes permit the use of the selecting keyboard unit in damp rooms, in environments involving an explosion hazard, and in similar environments. It is apparent that in the keyboard unit proposed here each key has a reed contact associated with it and interlocking is not effected mechanically by complicated cam bars but electrically by suitable logic circuits connecting the sets of encoding contacts.
The reed contacts are preferably secured to a common contact-carrying plate, which is parallel to the keyboard.
The key stems extend suitably through apertures in a slider plate and protrude close to the reed contacts and they are provided on their side faces with cams, which cooperate with projecting portions of the edges of the apertures of the slider plate in such a manner that in response to each actuation of a key, the slider plate is shifted against a biasing force which acts in the plane of the slider plate. In response to a shifting of the slider plate resulting from the actuation of a key, the slider plate actuates a set of contacts for enabling a talking circuit~
It is appare~t that the selecting keyboard unit proposed here can be assembled simply in that several plate assemblies are stacked because all sets of encoding contacts and the set of contacts for enabling a-talking circuit rest on a ~ contact-carrying plate and the keys of the keyboard as well as : the slider plate are disposed opposite to the contact-carrying plate.
:
This invention relates to a selecting keyboard unit, particularly for telephone systems, comprising a plurality of selecting keys, which are guided in a housing and operable to actuate sets of encoding contacts.
In known selecting keyboard units, transverse bars are secured to the key stems and e:Ktend into profiled slots of cam bars, which in response to the operation of a given key are shifted to actuate sets of encoding contacts. By means of the profiled slots in the cam bars, the keys are interlocked in such a manner that a simultaneous operation of more than one key cannot result in a simultaneous closing of the associated sets of encoding contacts.
The known selecting keyboard units have the dis-advantage that the mechanical means for actuating the contacts are extremely complicated so that the assembly is difficult and the manufacture of the selecting keyboard unit is highly expensiveO
It is a feature of the present invention to provide a selecting keyboard unit which can be simplified considerably and permits the enabling of a talking circuit by a set of contacts which is similar to the sets of encoding contacts.
In a selecting keyboard unit of the kind described first hereinbefore that feature is accomplished in accordance with the invention by the provision of;permanent magnets secured to respective key stems and of reed contacts secured in the houslng near t'ne end of the paths of the respective key stems.
:
~.;
:'~ .
~ 16~7~
Accord.ing to a fu:rther broad aspect of the present invention there 1s provided a selecting keyboard unit, partlcularly for telephone systems. The unit comprises a plurality of selecting keys which are guided in a housing and operable to actuate sets of enc~d~ng contacts. Permanent Inagnets are secured to respective key stems of the selecting keys and reed contacts are secured in the housing near the end of the paths of the respectlve key stems. The key board unit is characterized in that the reed contacts are secured to a common contact-carrying plate which i.s parallel to the keyboard and wherein the reed contacts are essentially diagonally oriented with respect to the cross-section of the housing.
- la -', '~
1 16877~
The reed contacts constitute the encoding contacts and because they are enclosed in glass tubes permit the use of the selecting keyboard unit in damp rooms, in environments involving an explosion hazard, and in similar environments. It is apparent that in the keyboard unit proposed here each key has a reed contact associated with it and interlocking is not effected mechanically by complicated cam bars but electrically by suitable logic circuits connecting the sets of encoding contacts.
The reed contacts are preferably secured to a common contact-carrying plate, which is parallel to the keyboard.
The key stems extend suitably through apertures in a slider plate and protrude close to the reed contacts and they are provided on their side faces with cams, which cooperate with projecting portions of the edges of the apertures of the slider plate in such a manner that in response to each actuation of a key, the slider plate is shifted against a biasing force which acts in the plane of the slider plate. In response to a shifting of the slider plate resulting from the actuation of a key, the slider plate actuates a set of contacts for enabling a talking circuit~
It is appare~t that the selecting keyboard unit proposed here can be assembled simply in that several plate assemblies are stacked because all sets of encoding contacts and the set of contacts for enabling a-talking circuit rest on a ~ contact-carrying plate and the keys of the keyboard as well as : the slider plate are disposed opposite to the contact-carrying plate.
:
- 2 `
7 ~ 8 In a preferred embodiment of the invention, the slider plate carries a permanent magnet, which cooperates with an additional reed contact that constitutes a set of contacts for enabling a talking circuit. That additional reed contact may also be mounted on the contact-carrying plate.
The additional reed contact which constitutes a set of contacts for enabling a talking circuit is preferably biased in the contact~open direction and is initially held always in a closed position by the permanent magnet whîch is secured to the slider plate. In response to the actuation of a key, the additional contact assumes its open position. That additional reed contact constitutes in operation a normally closed contact and the above-mentioned arrangement ensures a defined opening of the contact by the movement of the permanent magnet in a direction which is parallel to the plane of the contact-carrying plate.
A preferred embodiment of the invention will now be explained in more detail with reference to examples illustrated by the drawings, in which:
Figure 1 is a perspective exploded view combined with a block circuit diagram showing a selecting keyboard unit.
Figures2A and 2B are bottom views showing the housing of a selecting keyboard unit with a slider plate slidably mounted therein and a contact-carrying plate which can be inserted into the housing, and Figure 3 is a perspective view showing a key provided with a key stem and an aperture in the slider plate for the selecting keyboard unit shown in Figures 2A and 2B.
.
.
Figure 1 shows a keyboard unit 1 having a housing front plate 2, which comprises guide chambers for receiving keys 3. The guide chambers are not specifically shown on the drawing. The keys 3 are biased upwardly in Figure 1 by coil springs and are joined to key stems ~, which at their lower ends carry permanent magnet pieces 5 consisting of ferrite blocks and the like.
When one of the keys 3 is depressed against the force of the associated biasing spring, the associated perrnanent magnet 5 secured to the key stem ~ is moved so close to a registering reed contact 6 secured in the selecting keyboard unit that said contact is actuated in a known manner. In the present case~ the actuation of reed contacts affords the advantage that the reed contacts associated with all keys 3 can be arranged in one plane so that the overall height can be minimized.
The reed contacts 6 are actuated in direct response to the approach of the permanent magnets 5 without need for a mechanical diversion of force.
All reed contacts 6 are mounted on a contact-carry~
ing plate 7, which is mounted in the housing of the selecting keyboard unit and parallel to the keyboard. Details of this arrangement are not shown in Figure 1 for the sake of simplicity.
The reed contacts associated with the keys 3 serve for encoding in accordance with the symbols which are provided on the visible faces of the keys. By an additional reed contact 8, the code signal generated in response to the depression of one of the keys 3 is delivered to an interpreting circuitO The reed contact 8 is actuated by a permanent magnet piece 9, which is secured to a slider plate 10.
7 7 ~
The slider plate 10 has a number of apertures, through which the key stems ~ extend from the keys into the region of the reed contacts. The side faces of the key stems 4 are integrally formed with cams, which cooperate with pro-truding portions of the edges defining the apertures in the slider plate 10 in such a manner that the slider plate 10 is shifted to the right in Figure 1 in response to the depression of each of the keys 3.
A spring 11 urges the slider plate 10 to the left.
In response to the actuation of any one of the keys 3, the slider plate is shifted to the right against the force of the spring 11.
In that case the permanent magnet piece 9 is moved to the right from a position in which it registered with the reed contact 8.
As a result, the contact set which was previously held closed by the permanent magnet 9 now moves to an open position so that a short circuit in a selecting pulse-generating electronic circuit 12 connected to the reed contacts is eliminated and the selecting pulses can be delivered to the telephone line. Figure 1 shows a talking circuit 13, which is connected to the selecting pulse-generating circuit as soon as the actuation of a key has shiftedthe slider plate 10 sufficiently for the reed contact 8 to interrupt the short circuit in the circuit 12.
It will be understood that the keyboard may comprise more keys than are shown by way of example in Figure 1. In that case a corresponding number of reed contacts 6 must be provided.
Figures 2A and 2s show a unit comprising ten selecting keys and a set of contacts for enabling a talking circuit. The selecting keyboard-unit shown in Figure 2A comprises a housing 14, in which ten selecting keys are slidably mounted in guide chambers. Each selecting key is provided with a key stem 4, which is substantially rectangular in cross-section. It is apparent from Figure 3 that the cross-section of each key stem 7 'd is offset by a certain angle from the cross-section of the associated key. ~he significance of the feature will be discussed in more detail hereinafter.
The key stems 4 extend through the apertures 15 of the slider plate 10. By means of slots 16 in the slider plate 10 and pins or screws 17 extending through the slots, the siider plate is constrained to be slidable only parallel to the front plate of the housing of the selecting keyboard unit.
A helical compression spring 11 is provided, which urges the slider plate in the direction in which it is slidable in the housing of the selecting keyboard unit. The contact-carrying plate 7 is adapted to be inserted into the housing of the selecting keyboard unit to face the inner ends of the key stems 4 and carries ten reed contacts 6, which serve as sets of encoding contacts, and an additional reed contact 8, which serves to enable a talking circuit. In response to an actuation of any one of the keys the slider plate of the selecting keyboard unit shown in Figures 2A and 2B is shifted in a diagonal direction so that the permanent magnet piece 9 is moved away from the reed contact 8 mounted on the contact-carry-ing plate 7. As a result, the reed contact 8 opens so that the talking circuit is enabled. In accordance with the direction of movement of the slider plate 10, the reed contacts are mounted on the contact-carrying plate 7 in a diagonal orientation so that the provision of the terminals for the reed contacts will be simplified.
Figure 3 shows how each key stem 4 is connected to the associated key 3 in order to ensure that a diagonal movement will be imparted to the slider plate 10. It is also apparent from Figure 3 that the key stem 4 is surrounded by a coil spring, which bears on the bottom of the guide chamber of the housing of the selecting keyboard unit and biases the key 3 out of the keyboard. The ~sey ~ody is held captive in the guide chamber of the housing of the selecting keyboard unit by suitable projections provided on the key body. This i5 apparent to a per,son skilled in the art from Figure 3.
Attention is directed to the simple design of the selecting keyboard unit which i8 proposed here and cornprises platelike components which can be stacked. The tolerances re~uired can be adhered to without difficulty.
7 ~ 8 In a preferred embodiment of the invention, the slider plate carries a permanent magnet, which cooperates with an additional reed contact that constitutes a set of contacts for enabling a talking circuit. That additional reed contact may also be mounted on the contact-carrying plate.
The additional reed contact which constitutes a set of contacts for enabling a talking circuit is preferably biased in the contact~open direction and is initially held always in a closed position by the permanent magnet whîch is secured to the slider plate. In response to the actuation of a key, the additional contact assumes its open position. That additional reed contact constitutes in operation a normally closed contact and the above-mentioned arrangement ensures a defined opening of the contact by the movement of the permanent magnet in a direction which is parallel to the plane of the contact-carrying plate.
A preferred embodiment of the invention will now be explained in more detail with reference to examples illustrated by the drawings, in which:
Figure 1 is a perspective exploded view combined with a block circuit diagram showing a selecting keyboard unit.
Figures2A and 2B are bottom views showing the housing of a selecting keyboard unit with a slider plate slidably mounted therein and a contact-carrying plate which can be inserted into the housing, and Figure 3 is a perspective view showing a key provided with a key stem and an aperture in the slider plate for the selecting keyboard unit shown in Figures 2A and 2B.
.
.
Figure 1 shows a keyboard unit 1 having a housing front plate 2, which comprises guide chambers for receiving keys 3. The guide chambers are not specifically shown on the drawing. The keys 3 are biased upwardly in Figure 1 by coil springs and are joined to key stems ~, which at their lower ends carry permanent magnet pieces 5 consisting of ferrite blocks and the like.
When one of the keys 3 is depressed against the force of the associated biasing spring, the associated perrnanent magnet 5 secured to the key stem ~ is moved so close to a registering reed contact 6 secured in the selecting keyboard unit that said contact is actuated in a known manner. In the present case~ the actuation of reed contacts affords the advantage that the reed contacts associated with all keys 3 can be arranged in one plane so that the overall height can be minimized.
The reed contacts 6 are actuated in direct response to the approach of the permanent magnets 5 without need for a mechanical diversion of force.
All reed contacts 6 are mounted on a contact-carry~
ing plate 7, which is mounted in the housing of the selecting keyboard unit and parallel to the keyboard. Details of this arrangement are not shown in Figure 1 for the sake of simplicity.
The reed contacts associated with the keys 3 serve for encoding in accordance with the symbols which are provided on the visible faces of the keys. By an additional reed contact 8, the code signal generated in response to the depression of one of the keys 3 is delivered to an interpreting circuitO The reed contact 8 is actuated by a permanent magnet piece 9, which is secured to a slider plate 10.
7 7 ~
The slider plate 10 has a number of apertures, through which the key stems ~ extend from the keys into the region of the reed contacts. The side faces of the key stems 4 are integrally formed with cams, which cooperate with pro-truding portions of the edges defining the apertures in the slider plate 10 in such a manner that the slider plate 10 is shifted to the right in Figure 1 in response to the depression of each of the keys 3.
A spring 11 urges the slider plate 10 to the left.
In response to the actuation of any one of the keys 3, the slider plate is shifted to the right against the force of the spring 11.
In that case the permanent magnet piece 9 is moved to the right from a position in which it registered with the reed contact 8.
As a result, the contact set which was previously held closed by the permanent magnet 9 now moves to an open position so that a short circuit in a selecting pulse-generating electronic circuit 12 connected to the reed contacts is eliminated and the selecting pulses can be delivered to the telephone line. Figure 1 shows a talking circuit 13, which is connected to the selecting pulse-generating circuit as soon as the actuation of a key has shiftedthe slider plate 10 sufficiently for the reed contact 8 to interrupt the short circuit in the circuit 12.
It will be understood that the keyboard may comprise more keys than are shown by way of example in Figure 1. In that case a corresponding number of reed contacts 6 must be provided.
Figures 2A and 2s show a unit comprising ten selecting keys and a set of contacts for enabling a talking circuit. The selecting keyboard-unit shown in Figure 2A comprises a housing 14, in which ten selecting keys are slidably mounted in guide chambers. Each selecting key is provided with a key stem 4, which is substantially rectangular in cross-section. It is apparent from Figure 3 that the cross-section of each key stem 7 'd is offset by a certain angle from the cross-section of the associated key. ~he significance of the feature will be discussed in more detail hereinafter.
The key stems 4 extend through the apertures 15 of the slider plate 10. By means of slots 16 in the slider plate 10 and pins or screws 17 extending through the slots, the siider plate is constrained to be slidable only parallel to the front plate of the housing of the selecting keyboard unit.
A helical compression spring 11 is provided, which urges the slider plate in the direction in which it is slidable in the housing of the selecting keyboard unit. The contact-carrying plate 7 is adapted to be inserted into the housing of the selecting keyboard unit to face the inner ends of the key stems 4 and carries ten reed contacts 6, which serve as sets of encoding contacts, and an additional reed contact 8, which serves to enable a talking circuit. In response to an actuation of any one of the keys the slider plate of the selecting keyboard unit shown in Figures 2A and 2B is shifted in a diagonal direction so that the permanent magnet piece 9 is moved away from the reed contact 8 mounted on the contact-carry-ing plate 7. As a result, the reed contact 8 opens so that the talking circuit is enabled. In accordance with the direction of movement of the slider plate 10, the reed contacts are mounted on the contact-carrying plate 7 in a diagonal orientation so that the provision of the terminals for the reed contacts will be simplified.
Figure 3 shows how each key stem 4 is connected to the associated key 3 in order to ensure that a diagonal movement will be imparted to the slider plate 10. It is also apparent from Figure 3 that the key stem 4 is surrounded by a coil spring, which bears on the bottom of the guide chamber of the housing of the selecting keyboard unit and biases the key 3 out of the keyboard. The ~sey ~ody is held captive in the guide chamber of the housing of the selecting keyboard unit by suitable projections provided on the key body. This i5 apparent to a per,son skilled in the art from Figure 3.
Attention is directed to the simple design of the selecting keyboard unit which i8 proposed here and cornprises platelike components which can be stacked. The tolerances re~uired can be adhered to without difficulty.
Claims (6)
1. A selecting keyboard unit, particularly for telephone systems, comprising a plurality of selecting keys, which are guided in a housing and operable to actuate sets of encoding contacts, permanent magnets secured to respective key stems of said selecting keys and reed contacts secured in the housing near the end of the paths of the respective key stems, characterized in that said reed contacts are secured to a common contact-carrying plate, which is parallel to the keyboard, and wherein said reed contacts are essentially diagonally oriented with respect to the cross-section of the housing.
2. A selecting keyboard unit according to claim 1 wherein said key stems extend through apertures in a slider plate and protrude close to said reed contacts, each said stems being provided with a cam on a side face thereof, said cam of said stems cooperating with projecting portions of the edges of the apertures of the slider plate in such a manner that in response to each actuation of a key the slider plate is shifted against a biasing force which acts in the plane of the slider plate whereby said slider plate actuates a set of contacts for enabling a talking circuit.
3. A selecting keyboard unit according to claim 2, wherein said slider plate carries a permanent magnet, which cooperates with an additional reed contact that constitutes a set of contacts for enabling a talking circuit.
4. A selecting keyboard unit according to claim 1, wherein an additional reed contact is mounted on the contact-carrying plate.
5. A selecting keyboard unit according to claim 4, wherein said additional reed contact is biased in a contact-open direction and is held by the permanent magnet in a closed position when the slider plate has not been shifted.
6. A selecting keyboard unit according to claim 2, 3, or 4, wherein said slider plate is guided in said housing by slots and pins extending through said slots.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3017010.6 | 1980-05-02 | ||
| DE19803017010 DE3017010C2 (en) | 1980-05-02 | 1980-05-02 | Keypad, in particular for telephone technology |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1168778A true CA1168778A (en) | 1984-06-05 |
Family
ID=6101548
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000376694A Expired CA1168778A (en) | 1980-05-02 | 1981-05-01 | Selecting keyboard unit, particularly for telephone systems |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1168778A (en) |
| DE (1) | DE3017010C2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1665733B1 (en) * | 1966-09-02 | 1970-07-09 | Siemens Ag | Key switches, especially for telecommunication devices |
| DE1928000A1 (en) * | 1969-03-10 | 1970-12-10 | Merk Gmbh Telefonbau Fried | Mechanically coding dial pad |
-
1980
- 1980-05-02 DE DE19803017010 patent/DE3017010C2/en not_active Expired
-
1981
- 1981-05-01 CA CA000376694A patent/CA1168778A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3017010A1 (en) | 1981-11-19 |
| DE3017010C2 (en) | 1984-04-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |