Textiles: spinning – twisting – and twining – Apparatus and processes – Unitary multiple twist devices
Reexamination Certificate
1999-04-30
2001-04-03
Calvert, John J. (Department: 3741)
Textiles: spinning, twisting, and twining
Apparatus and processes
Unitary multiple twist devices
C057S003000, C057S006000, C057S016000, C057S058490, C057S058520, C057S058540, C057S059000, C057S127500, C057S294000, C174S027000, C174S11000P, C174S11300R
Reexamination Certificate
active
06209299
ABSTRACT:
BACKGROUND OF THE INVENTION
Electrical cables are commonly used to transmit analog signals and digital data. These cables often include a pre-twisted pair of wires to improve electrical and mechanical properties. These pre-twisted wires are cabled or paired together in a cabling device at typically high speeds which impart significant forces, e.g, tension, to the wires often deforming them.
Industry specifications dictating the strain on wires during cabling are stringent, e.g., the wire's conductor cannot be stretched more than 1/10,000 of an inch measured across the diameter. These specifications can result in a substantial amount of discarded wire.
U.S. Pat. No. 3,969,880 to Maillefer et al. describes a cabler that incorporates a capstan or pulling device inside of a rotating doubletwisting bow. The wire is twisted as the wire enters the bow, and then is fed down one side of the bow and twisted again at the other side of the bow after which the wire is taken up. At higher speeds, the capstan must pull the wire with higher tensile forces due to the frictional forces acting on the wire through the bow. This often pulls the wire out of specification.
Another prior art system avoids using a capstan and pulls the wire through the bow using the take-up reel. This system suffers from the same deficiency in that the wire is pulled through the bow with increased tension as the rotational speed of the bow increases often resulting in damaged wire.
SUMMARY OF THE INVENTION
Accordingly, a need exists for a cabler device which pulls wire through a rotating bow with minimal tensile force.
A need also exists for a cabler device which can counteract and minimize oscillating forces acting on the wire through the bow.
An apparatus to accomplish the foregoing comprises a first twisting device that dispenses a first wire and imparts a pre-twist to the same, a second twisting device that receives the twisted first wire and twists the same about a second wire. A metering device or capstan positioned on the outside of the second twisting device controls the input velocity of the first and second wires. The apparatus can further include a third twisting device that dispenses the second wire and imparts a pre-twist to the same. In a preferred embodiment of the present invention, the second twisting device receives the first and second wires and twins or pairs the same. Preferably, the first and third twisting devices impart a respective back-twist to the first and second wires.
A transducer that measures the tension of the first and second wires before the second twisting device twins the same is provided in accordance with the present invention. The tension measurement is forwarded to a controller.
According to other aspects of the present invention, a take-up reel and motor are provided on the second twisting device to take-up the twinned first and second wires. The take-up reel motor rotates in response to a control signal from the controller to thereby control the tension of the first and second wires through the second twisting device.
According to further aspects of the present invention, the second twisting device includes a traverse assembly to lay the wires onto a take-up reel. The traverse assembly includes a damping mechanism to maintain the tension in the wires substantially constant in a preferred embodiment.
The first and third twisting devices each include a pay-off reel that dispenses the first and second wires, each pay-off reel being rotated by a respective pay-off reel motor. The first and third twisting devices each further include a damping mechanism that takes up slack in the dispensing of the first and second wires.
Each twisting device includes a bow assembly rotated by a respective motor for twisting the wires. In a preferred embodiment of the present invention, each twisting device is vertically oriented.
A dancer assembly, which can also be referred to as a buffer assembly, is associated with the first and third twisting devices for taking up slack in the dispensing of the first and second wires and thereby control tension and velocity of the same.
An apparatus is also provided including first twisting means for dispensing a first wire and imparting a twist to the same, second twisting means for receiving the twisted first wire and twisting the same about a second wire. Metering means is positioned on the outside of the second twisting device for controlling the input velocity of the first and second wires. The apparatus can further include third twisting means for dispensing the second wire and imparting a twist to the same. Transducer means is also provided for measuring the tension of the first and second wires before the second twisting twists the same. This measurement is forwarded to a controller which controls the tension or torque of the take-up reel motor such that the tension through the second twisting means is substantially constant.
Also in accordance with the present invention, a method of twisting wire is provided comprising measuring the tension of a wire before it enters a twisting device, forwarding the tension measurement to a controller, and controlling the torque of a take-up reel in response to a set of programmed instructions. The take-up reel takes up the twisted wire in response to the tension measurement such that the tension in the twisting device is substantially constant. The method further includes the step of controlling the input speed of the wire with a capstan positioned before the wire enters the twisting device. In a preferred embodiment of the present invention, the wire is back-twisted before entering the twisting device.
According to yet a further aspect of the present invention, a back-twist is imparted to a second wire wherein the first and second wires are twinned in the twisting device.
REFERENCES:
patent: 3732682 (1973-05-01), Crotty et al.
patent: 3969880 (1976-07-01), Maillefer et al.
patent: 4044538 (1977-08-01), Hoside
patent: 4182105 (1980-01-01), Tokuji
patent: 4233807 (1980-11-01), Venable
patent: 5619016 (1997-04-01), Newmoyer
patent: 5622039 (1997-04-01), Thompson
patent: 5767441 (1998-06-01), Brorein et al.
patent: 5814768 (1998-09-01), Wessels et al.
patent: 5966917 (1999-10-01), Thompson
patent: 459 621 (1981-10-01), None
Landry Ernest L.
McKeon Timothy P.
Calvert John J.
Hamilton Brook Smith & Reynolds P.C.
Hurley Shaun R.
Thermoplastics Engineering Corp.
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