Patent US3644932A successfully refreshed from Google Patents.
US3644932A
Expired / Lapsed
US
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High-speed indenting recorder
Assignee: Synergistics Inc
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Filing: 1969-10-08
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Granted: 1972-02-22
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Expires: 1989-10-08
Abstract
Abstract An electromechanical indenting recorder consists of a solenoid coil, a ferromagnetic housing about the coil, and a nonferromagnetic plunger that moves inside the core. The plunger has a ferromagnetic cover attached thereto which cover extends at least in part over the core and the housing forming an annular airgap therebetween. The cover serves to stop the movement of the plunger by contacting said housing, and the core cover, core and housing form a magnetic circuit with the airgap. An indenting knife is carried by one end of the plunger opposite from the cover and in operation serves to make a series of indentations, usually in a binary code form, in a suitable receptor sheet such as a pocket credit card. The plunger and cover are very light such that they can move rapidly under the influence of the magnetic field created when the solenoid is energized. The solenoid is initially energized and midway through the stroke of the plunger the driver current is cut off and the solenoid circuit remains closed through a diode such that the plunger continues accelerating towards the stop position under the influence of the decaying field of the magnetic circuit. The efficiency of the device is high and the excess heat generated is at a minimum.
Inventors
- 👤 John G Wallace
- 👤 Edmund Schreiner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:00
CPC Classifications
G; G06; G06K; G06K1/00; G06K1/12; H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/16; H01F7/1638; Y; Y10; Y10T; Y10T83/00; Y10T83/869; Y10T83/8765; Y10T83/8768
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
220 words
An electromechanical indenting recorder comprising: a. a solenoid coil; b. a ferromagnetic housing about said coil; c. a nonferromagnetic plunger within said coil movable along the axis of said coil from a normally open position to a stop position; d. a ferromagnetic cover attached to said plunger and extending at least in part over said housing forming an airgap therebetween, said cover serving to stop the movement of said plunger by contacting said housing and said coil, cover and housing forming a magnetic circuit with said airgap; e. an indenting knife carried by one end of said plunger opposite said cover and extending beyond said housing when said plunger is in said stop position; f. spring means operatively associated with said plunger to bias said plunger in said normally open position; g. energizing means for energizing said magnetic circuit and magnetically saturate said airgap sufficient to cause said plunger and cover to accelerate towards said stop position against the resistance of said spring means, said energizing means including means to cease the flow of current and short circuit said coil when said plunger is moving from said normally open position towards said stop position in a position intermediate therebetween so that said plunger continues to said stop position under the influence of the decaying magnetic field in said magnetic circuit.
Claim 2
Dependent Claim
220 words
An electromechanical indenting recorder comprising: a. a solenoid coil; b. a ferromagnetic housing about said coil; c. a nonferromagnetic plunger within said coil movable along the axis of said coil from a normally open position to a stop position; d. a ferromagnetic cover attached to said plunger and extending at least in part over said housing forming an airgap therebetween, said cover serving to stop the movement of said plunger by contacting said housing and said coil, cover and housing forming a magnetic circuit with said airgap; e. an indenting knife carried by one end of said plunger opposite said cover and extending beyond said housing when said plunger is in said stop position; f. spring means operatively associated with said plunger to bias said plunger in said normally open position; g. energizing means for energizing said magnetic circuit and magnetically saturate said airgap sufficient to cause said plunger and cover to accelerate towards said stop position against the resistance of said spring means, said energizing means including means to cease the flow of current and short circuit said coil when said plunger is moving from said normally open position towards said stop position in a position intermediate therebetween so that said plunger continues to said stop position under the influence of the decaying magnetic field in said magnetic circuit.
Claim 3
Dependent Claim
21 words
The recorder of claim 1 wherein said decaying magnetic field substantially parallels the field required to maintain saturation in said airgap.
Claim 4
Dependent Claim
18 words
The recorder of claim 1 wherein said plunger, cover and indenting knife together weigh less than 0.001 pound.
Claim 5
Dependent Claim
36 words
The recorder of claim 1 wherein said housing is in thermally conductive contact with and is carried by a substantially larger mass of metal having a relatively large surface area that serves as a heat sink.
Claim 6
Dependent Claim
36 words
The recorder of claim 4 wherein said coil and arm are combined into a single component with a single coil turn, the arm being divided to serve as two current paths to and from the coil.
Claim 7
Dependent Claim
217 words
In an electromechanical indenting recorder having a solenoid, a movable nonferromagnetic plunger therein, one end thereof carrying an indenting knife, a ferromagnetic housing about said solenoid, a ferromagnetic core cover attached to said plunger and forming with said housing an annular air gap about the axis of said plunger when said plunger iS in a rest position, and a spring means biasing said plunger and cover in said rest position, said core, cover and housing forming with said air gap a magnetic circuit, said plunger and cover being adapted to being accelerated to an indenting position by the field created by said magnetic circuit when a current is applied to said solenoid, said cover coming to a stop position against said housing when said plunger reaches the maximum indenting position; the improved method of operation thereof comprising: initially applying current to said coil to cause said magnetic circuit rapidly to become saturated and to accelerate said plunger towards said indenting position against the resistance of said spring means, ceasing the flow of said current and short circuiting said solenoid when said plunger is moving at a position intermediate of said rest and stop positions and allowing said plunger to continue to said stop position under the influence of the resulting decaying magnetic field in said magnetic circuit.
Claim 8
Dependent Claim
217 words
In an electromechanical indenting recorder having a solenoid, a movable nonferromagnetic plunger therein, one end thereof carrying an indenting knife, a ferromagnetic housing about said solenoid, a ferromagnetic core cover attached to said plunger and forming with said housing an annular air gap about the axis of said plunger when said plunger iS in a rest position, and a spring means biasing said plunger and cover in said rest position, said core, cover and housing forming with said air gap a magnetic circuit, said plunger and cover being adapted to being accelerated to an indenting position by the field created by said magnetic circuit when a current is applied to said solenoid, said cover coming to a stop position against said housing when said plunger reaches the maximum indenting position; the improved method of operation thereof comprising: initially applying current to said coil to cause said magnetic circuit rapidly to become saturated and to accelerate said plunger towards said indenting position against the resistance of said spring means, ceasing the flow of said current and short circuiting said solenoid when said plunger is moving at a position intermediate of said rest and stop positions and allowing said plunger to continue to said stop position under the influence of the resulting decaying magnetic field in said magnetic circuit.
Claim 9
Dependent Claim
28 words
The improvement of claim 6 wherein said decaying magnetic field maintains a saturated condition in said airgap such that said plunger continues to accelerate towards said stop position.
Claim 10
Dependent Claim
32 words
The improvement of claim 6 wherein said plunger is returned to said rest position by said spring means, and the cycle is then repeated at a rate exceeding 500 times a second.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |