US3858095A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective circuit arrangement for band cutter machines
Assignee: RIEDL A oHG DT
•
Filing: 1973-08-28
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Granted: 1974-12-31
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Expires: 1993-08-28
Abstract
Abstract A protective circuit arrangement for a motor driven band cutter machine, wherein the band cutter is electrically insulated from the rest of the machine and is connected as capacitance in a bridge circuit which is balanced during normal operation and which when unbalanced provides an output signal by which full braking of the band cutter is triggered.
Inventors
- 👤 W Friemann
- 👤 J Proschka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:18
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/08; G01V3/088; F; F16; F16P; F16P3/00; F16P3/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
61 words
A protective device for use in cutting machines having a moving cutting member comprising: safety circuit means, responsive to touching of the cutting member by an operator, for generating an Output signal; and braking means electrically connected to said safety circuit means for substantially instantaneously stopping the cutting member in response to said generated output signal of said safety circuit means.
Claim 2
Dependent Claim
61 words
A protective device for use in cutting machines having a moving cutting member comprising: safety circuit means, responsive to touching of the cutting member by an operator, for generating an Output signal; and braking means electrically connected to said safety circuit means for substantially instantaneously stopping the cutting member in response to said generated output signal of said safety circuit means.
Claim 3
Dependent Claim
78 words
The protective device of claim 1 wherein said cutting member comprises a band cutter having a drive motor; and said safety circuit means comprises a bridge circuit balanced during normal operation and when unbalanced by the operator touching the band cutter provides an output signal by which full braking of said band cutter is triggered, wherein said band cutter is electrically insulated from the rest of the cutting machine and is connected as capacitance in said bridge circuit.
Claim 4
Dependent Claim
17 words
A protective device according to claim 2 wherein said bridge circuit is energized by an oscillator voltage.
Claim 5
Dependent Claim
29 words
A protective device according to claim 2 comprising an amplifier circuit and a circuit element connected to said output from said bridge circuit by way of said amplifier circuit.
Claim 6
Dependent Claim
40 words
A protective device according to claim 2 comprising a D.C. supply connected to the drive motor for the rapid braking of said drive motor when said drive motor is switched off, wherein said drive motor is a three-phase electric motor.
Claim 7
Dependent Claim
26 words
A protective circuit arrangement according to claim 2 wherein the band cutter has an electromechanical brake which is operated when the drive motor is switched off.
Claim 8
Dependent Claim
49 words
A protective device according to claim 4, wherein the balancing of said bridge circuit and the design of said circuit element and of said amplifier circuit is such that when said band cutter is touched by objects which are normally to be cut said circuit element is not operated.
Claim 9
Dependent Claim
43 words
A protective device according to claim 2 comprising an amplifier, and a reversing switch connected to said output from said bridge circuit by way of said amplifier, said reversing switch reversing the direction of said drive motor upon operation of said reversing switch.
Claim 10
Dependent Claim
43 words
A protective device according to claim 3 comprising an amplifier, and a reversing switch connected to said output from said bridge circuit by way of said amplifier, said reversing switch reversing the direction of said drive motor upon operation of said reversing switch.
Claim 11
Dependent Claim
43 words
A protective device according to claim 7 comprising an amplifier, and a reversing switch connected to said output from said bridge circuit by way of said amplifier, said reversing switch reversing the direction of said drive motor upon operation of said reversingg switch.
Claim 12
Dependent Claim
29 words
A protective device according to claim 3 comprising an amplifier circuit, and a circuit element connected to said output from said bridge circuit by way of said amplifier circuit.
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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |