US3604856A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic dialing system for telephones
Assignee: ZF International UK Ltd
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Filing: 1969-05-26
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Granted: 1971-09-14
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Expires: 1989-05-26
Abstract
Abstract An automatic dialing system for telephones having a plurality of rotatable memory units each of which contains a telephone address, selection means for selecting one of the plurality of memory units, and a dialing switch mechanism which is rotatable to dial digits, and which is urged towards its rest position by a return spring. The memory units and the dialing switch mechanism are connected to respective first and second outputs of a differential gear mechanism the input of which is driven by an electric motor, and a pawl assembly is associated with the memory units and is operable to prevent rotation of the memory units. A first cam is rotatable with the input of the gear mechanism, and a second cam is rotatable with the first output of the gear mechanism. A cam follower is urged into engagement with the first cam, and is engageable by the second cam, movement of the cam follower operating a switch to control energization of the electric motor driving the input of the gear mechanism. The first cam is provided with a depression which is engageable by the cam follower to break the electric motor circuit and the second cam has a lobe which is engageable with the cam follower to move the cam follower to complete the motor circuit. The cam follower is moved out of engagement with the depression in the first cam to energize the motor, whereafter the cam follower rides on the periphery of the first cam as the first cam rotates, the first cam being rotated through one complete revolution to perform a dialing cycle to dial a single digit. The first and second cams are displaced angularly when a digit is dialed so that at the end of a dialing cycle the motor is deenergized with the lobe of the second cam displaced angularly from the depression in the first cam, and the second cam then being rotated by return movement of the dialing switch mechanism so that subsequently the lobe lifts the cam follower to restart the motor whereafter a further dialing cycle is performed. The dialing system is stopped after the full address has been dialed by performing a cycle at the end of the address in which no digit is dialed, so that the cam follower engages the depression in the first cam fractionally after the lobe of the second cam has past the cam follower.
Inventors
- 👤 Gavin Patrick Blandy Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:46
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/26; H04M1/27; H04M1/274
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
406 words
An automatic dialling system for telephones including a plurality of rotatable memory units each of which contains a telephone address, a dialling switch mechanism rotatable from a rest position to any one of a plurality of positions dependent upon the digit to be dialled, and urged towards its rest position by a return spring, selection means for selecting one of said plurality of memory units, a differential gear mechanism having an input driven by an electric motor, a first output coupled to said memory units and a second output coupled to said dialling switch mechanism, a pawl assembly operable to prevent rotation of said memory units, a first cam rotatable with said input of said gear mechanism, a second cam rotatable with said first output of said gear mechanism, a cam follower resiliently urged into engagement with said first cam, and engageable by said second cam, and a switch operable by movement of said cam follower to control energization of said electric motor, said first cam having a depression engageable by said cam follower to permit said cam follower to move in a direction to break the motor circuit and said second cam having a lobe engageable with said cam follower to move the cam follower in a direction to complete the motor circuit and the arrangement being such that in use the cam follower is moved out of engagement with the depression in the first cam so that the motor is energized, whereafter the cam follower rides on the periphery of the first cam as the first cam is rotated, the first cam being rotated through one complete revolution to perform a dialling cycle to dial a single digit, and the first and second cams being displaced angularly when a digit dialled so that at the end of a cycle the motor is deenergized with said lobe displaced angularly from said depression, the second cam then being rotated by the return movement of the dialling switch mechanism so that said lobe lifts said cam follower out of engagement with said depression to restart the motor whereafter a further cycle is perFormed, and the system being stopped after the full address has been dialled by performing a cycle at the end of the address in which no digit is dialled, so that the cam follower engages said depression fractionally after said lobe has passed the cam follower and said dialling switch mechanism has not been operated.
Claim 2
Dependent Claim
406 words
An automatic dialling system for telephones including a plurality of rotatable memory units each of which contains a telephone address, a dialling switch mechanism rotatable from a rest position to any one of a plurality of positions dependent upon the digit to be dialled, and urged towards its rest position by a return spring, selection means for selecting one of said plurality of memory units, a differential gear mechanism having an input driven by an electric motor, a first output coupled to said memory units and a second output coupled to said dialling switch mechanism, a pawl assembly operable to prevent rotation of said memory units, a first cam rotatable with said input of said gear mechanism, a second cam rotatable with said first output of said gear mechanism, a cam follower resiliently urged into engagement with said first cam, and engageable by said second cam, and a switch operable by movement of said cam follower to control energization of said electric motor, said first cam having a depression engageable by said cam follower to permit said cam follower to move in a direction to break the motor circuit and said second cam having a lobe engageable with said cam follower to move the cam follower in a direction to complete the motor circuit and the arrangement being such that in use the cam follower is moved out of engagement with the depression in the first cam so that the motor is energized, whereafter the cam follower rides on the periphery of the first cam as the first cam is rotated, the first cam being rotated through one complete revolution to perform a dialling cycle to dial a single digit, and the first and second cams being displaced angularly when a digit dialled so that at the end of a cycle the motor is deenergized with said lobe displaced angularly from said depression, the second cam then being rotated by the return movement of the dialling switch mechanism so that said lobe lifts said cam follower out of engagement with said depression to restart the motor whereafter a further cycle is perFormed, and the system being stopped after the full address has been dialled by performing a cycle at the end of the address in which no digit is dialled, so that the cam follower engages said depression fractionally after said lobe has passed the cam follower and said dialling switch mechanism has not been operated.
Claim 3
Dependent Claim
110 words
A system as claimed in claim 1 wherein said first cam is movable angularly relative to said input, said first cam being resiliently urged to move angularly relative to the input so that when said cam follower is moved out of engagement with said first cam said first cam moves angularly relative to said input thereby displacing said depression from the cam follower so that when the cam follower reengages the first cam it engages the periphery thereof, said first cam being returned to its original angular position relative to the input during rotation of the cam by friction between the periphery of the first cam and the cam follower.
Claim 4
Dependent Claim
62 words
A system as claimed in claim 1 wherein said outputs of said differential gear mechanism are rotated by the input of the mechanism at half the speed of rotation of the input, and said second cam is provided with a second lobe engageable with the cam follower, said second lobe being spaced around the second cam by 180* from said one lobe.
Claim 5
Dependent Claim
63 words
A system as claimed in claim 3 wherein said second lobe is of greater arcuate length than said one lobe, said second lobe serving at the end of dialling an address to prevent the cam follower engaging in the depression in said first cam to switch off the motor when the memory units are displaced angularly from a desired datum position, by 180*.
Claim 6
Dependent Claim
153 words
A system as claimed in claim 1 wherein said cam follower includes a ferrous metal member which is engageable by a permanent magnet carried by a linkage movable in response to selection of one of said memory units, the movement of the linkage during selection of one of said memory units serving to move said magnet and by virtue of the attraction between said magnet and said ferrous metal member, serving also to move said cam follower out of engagement with said first cam to operate said switch, the arrangement being such that said cam follower is arrested before said linkage has completed the movement necessary to complete the selection of the memory unit so that the magnet is moved away from the ferrous metal member thereby overcoming the attraction between the magnet and the ferrous metal member and allowing the cam follower to move to engage the periphery of said first cam.
Claim 7
Dependent Claim
128 words
A system as claimed in claim 1 wherein said selection means includes a plurality of manually depressable buttons each of which is associated with a respective memory unit depression of any one of the buttons serving to select its associated memory unit for dialling, to operate the system so that the system is in a condition to commence dialling and to open a further switch to prevent the commencement of dialling by breaking the electrical circuit of the motor, said further switch remaining open until the button is released whereupon the system will commence dialling the address contained in the memory unit associated with the depressed button, the operation of said further switch by said button permitting the operator to delay dialling until an external telephone line opens.
Claim 8
Dependent Claim
43 words
A system as claimed in claim 6 wherein the buttons operate said further switch through a followup linkage so that initial depression of the selected button opens the switch and the initial outward movement of the button upon release thereof closes said switch.
Claim 9
Dependent Claim
187 words
A system as claimed in claim 6 for use with an internal telephone installation wherein a letter or digit is dialled to connect the internal installation to the external telephone lines the system being modified in that opening of said further switch completes a second circuit to the motor through a switching device, so that dialling of the address contained in the memory unit associated with the deprEssed button commences when the button is depressed, said switching device being operated, in response to dialling of the first letter or digit of the address, to break said second circuit to the motor, so that operation of the system ceases after the first letter or digit has been dialled, and the system remaining inoperative until said button is released whereupon the further switch closes and the remainder of the address is dialled, the first letter or digit of the address being the access letter or digit which when dialled connects the internal installation with the external telephone lines and the system permitting the operator to prevent dialling of the external part of the address until an external line opens.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |