Patent US3590567A successfully refreshed from Google Patents.
US3590567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling the tension in flexible material being helically wrapped about an elongated core
Assignee: Balfour Beatty PLC
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Filing: 1969-04-15
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Granted: 1971-07-06
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Expires: 1989-04-15
Abstract
Abstract The tension in elongated flexible material being drawn from a drum or over a capstan is controlled by an electromagnetically operated friction brake acting on the drum or capstan. The whole of the electrical power for operating the brake is obtained from a high-gain DC amplifier which has in its input circuit an impedance whose value is varied in accordance with the position of a sensing device which moves in accordance with changes in tension against a substantially constant biasing force. The system is stabilized to prevent hunting.
Inventors
- 👤 Zbigniew Bonikowski
- 👤 Peter Harvey
- 👤 Bruce Henry Keen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:53
CPC Classifications
D; D07; D07B; D07B7/00; D07B7/02; D07B7/14; B; B65; B65H; B65H23/00; B65H23/04; B65H23/044; B65H23/06; B65H23/063; B65H59/00; B65H59/02; B65H59/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
107 words
Apparatus for controlling the tension in elongated flexible material as it is being drawn in engagement with a rotating member, comprising an electromagnetically operated friction brake acting on the rotating member, a high gain DC amplifier capable of supplying the whole of the electrical power for operating the brake, a sensing device which moves in accordance with changes in tension in the flexible material against a substantially constant biasing force, a variable impedance in the input circuit of the amplifier, means for varying the value of the variable impedance in accordance with the position of the sensing device and means for stabilizing the system to prevent hunting.
Claim 2
Dependent Claim
107 words
Apparatus for controlling the tension in elongated flexible material as it is being drawn in engagement with a rotating member, comprising an electromagnetically operated friction brake acting on the rotating member, a high gain DC amplifier capable of supplying the whole of the electrical power for operating the brake, a sensing device which moves in accordance with changes in tension in the flexible material against a substantially constant biasing force, a variable impedance in the input circuit of the amplifier, means for varying the value of the variable impedance in accordance with the position of the sensing device and means for stabilizing the system to prevent hunting.
Claim 3
Dependent Claim
123 words
Apparatus as claimed in claim 1 in which the brake is arranged to act on a shaft and comprises an activating coil mounted, coaxially with the braked shaft, an annular channel-shaped steel pole piece surrounding the activating coil and having an open end lying in a plane at right angles to the shaft axis, a ring of friction material which closes the said open end of the pole piece, a hub secured to the shaft, a ring-shaped armature in splined engagement with the hub and capable of sliding axially towards and away from the friction ring on the hub, the armature being pulled into contact with the friction ring by the magnetic force generated in the pole piece upon energization of the coil.
Claim 4
Dependent Claim
36 words
Apparatus as claimed in claim 1 in which the sensing device comprises a pivoted arm, a spring applying a substantially constant biasing force to the pivoted arm, and a dancer roll carried on the pivoted arm.
Claim 5
Dependent Claim
35 words
Apparatus as claimed in claim 1 in which the sensing device comprises a pivoted arm, pneumatic means applying substantially constant biasing force to the pivoted arm and a dancer roll carried on the pivoted arm.
Claim 6
Dependent Claim
31 words
Apparatus as claimed in claim 1 in which the high gain DC amplifier is a multistage transistor amplifier which comprises an overall feedback circuit directly connecting its output with its input.
Claim 7
Dependent Claim
22 words
Apparatus as claimed in claim 1 in which the means for stabilizing the system comprises a resistance-capacitance network in the amplifier input.
Claim 8
Dependent Claim
135 words
In a lapping head for helically applying elongated flexible material to a core as it passes axially through the lapping head, apparatus for controlling the tension in the elongated flexible material as it is being drawn in engagement with a rotatable member and applied to the advancing core, comprising an electromagnetically operated friction brake acting on the rotating member, a high gain DC amplifier capable of supplying the whole of the electrical power for operating the brake, a sensing device which moves in accordance with changes in tension in the flexible material against a substantially constant biasing force, a variable impedance in the input circuit of the amplifier, means for varying the value of the variable impedance in accordance with the position of the sensing device and means for stabilizing the system to prevent hunting.
Claim 9
Dependent Claim
135 words
In a lapping head for helically applying elongated flexible material to a core as it passes axially through the lapping head, apparatus for controlling the tension in the elongated flexible material as it is being drawn in engagement with a rotatable member and applied to the advancing core, comprising an electromagnetically operated friction brake acting on the rotating member, a high gain DC amplifier capable of supplying the whole of the electrical power for operating the brake, a sensing device which moves in accordance with changes in tension in the flexible material against a substantially constant biasing force, a variable impedance in the input circuit of the amplifier, means for varying the value of the variable impedance in accordance with the position of the sensing device and means for stabilizing the system to prevent hunting.
Claim 10
Dependent Claim
92 words
Apparatus as claimed in claim 7 in which the sensing device comprises an arm which lies in a radial plane passing through the axis of rotation of the head, is rotatable in that plane about a pivot perpendicular thereto, means for applying a substantially constant biasing force to the arm, a dancer roller carried on the arm, and means for passing a loop of the flexible material over the dancer roller in a direction such that the arm lies substantially perpendicular to said axis when the tension is at its optimum value.
Claim 11
Dependent Claim
148 words
Apparatus for controlling the tension in a plurality of lengths of flexible material as they are being drawn in engagement with respective rotatable members, comprising for each length a system comprising an electromagnetically operated friction brake acting on the respective rotatable member, a high gain DC amplifier capable of supplying the whole of the electrical power for operating the brake, a sensing device which moves in accordance with changes in tension in the associated length of flexible material against a substantially constant biasing force, pneumatic means for applying said biasing force, a variable impedance in the input circuit of the amplifier, means for varying the value of the variable impedance in accordance with the position of the sensing device, and means for stabilizing the system to prevent hunting; and a reservoir, common to all of the plurality of systems, for supplying fluid to the said pneumatic biasing means.
Claim 12
Dependent Claim
148 words
Apparatus for controlling the tension in a plurality of lengths of flexible material as they are being drawn in engagement with respective rotatable members, comprising for each length a system comprising an electromagnetically operated friction brake acting on the respective rotatable member, a high gain DC amplifier capable of supplying the whole of the electrical power for operating the brake, a sensing device which moves in accordance with changes in tension in the associated length of flexible material against a substantially constant biasing force, pneumatic means for applying said biasing force, a variable impedance in the input circuit of the amplifier, means for varying the value of the variable impedance in accordance with the position of the sensing device, and means for stabilizing the system to prevent hunting; and a reservoir, common to all of the plurality of systems, for supplying fluid to the said pneumatic biasing means.
References Cited (Backward Citations)
US2875570A
Cited
US3233397A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-05 | 1975-01-04 | 1975-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-05 | 1979-01-04 | 1979-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-05 | 1983-01-04 | 1983-07-06 | $7700.00 | Window Closed / Lapsed |