US2568466A - Contacting device for moving wires - Google Patents

Description

sept. 1s, 1951 l con 25689166 I CONTACTING DEVICE` FOR MOVING WIRES Filed arch 18, 1949 lnvenor': Benjamin B. Scott QNX/mr.

.d HiS Attorney.

Patented Sept. 18, 1951 2,568,466 CONTACTING DEVICE FOR MOVING WIRES Benjamin B. Scott, Schenectady, N. Y., assigner to General Electric Company, a corporation of New York Application March 18, 1949, Serial No. 82,113

6' Claims. l

My invention relates to devices for the continuous electric contacting of insulated and bare moving wires.

Precision linear and non-linear resistance cards for use in variable resistance units are Wound on a winding machine in conformance with a master resistance. Previously, contact fingers were employed which brushed the edge of the card being wound to obtain the resistance of each turn as it was wound. The lead or spacing of the succeeding turn was then compensated by a Wheatstone bridge means to conform to the turn resistance of the master.

This form of contact is inherently poor and this method merely compensated for incorrect positioning of turns rather than positioning the turns accurately as they are wound. My copending applications S. N. 68,818, led January 3, 1949, and having the same assignee, describes a device for the continuous contacting of bare or insulated wires moving at high speeds. This application employs a similar serrated contact wheel, but the necessary removal of insulation limits the speed of the present device and dictates the inclusion of a tension compensating device to overcome the added inertia of the insulation scraping device.

The object of my present invention is to provide a tension-compensated contacting device for moving wires under variable tension that will provide satisfactory contact with more heavily insulated wires, and with insulated wires of small diameter in order that wire turns may be placed in their correct positions upon being wound and eliminate the need of spacing compensation of succeeding turns due to incorrect turn placement.

In accordance with my invention, a contacting device is mounted between the winding machine and the reel from which wire under tension is fed to the winding machine; I provide an insulating base upon which are pivotally mounted a pulley to receive wire and a pulley to direct wire leaving the device. The arm of a rotatable tension-shock absorbing device is pivoted to the base and supports two pivotally mounted intermediate pulleys and a serrated wheel mounted to provide paths of wire along said arm. A stripping means provided with'an adjustable blade is mounted on the arm adjacent one of these wire paths and adjusted so that as the wire passes the device, linsulation is scraped oil' over a sector along the entire length of the wire to bare the metal of the wire so it will make contact with the teeth of the serrated wheel. When mounted with the fiat portion so provided next to the supporting member, the wire is prevented from rolling out of position.

A brush over which the wire passes after the stripping process and a compressed 'air jet directed at the wire are mounted on the arm to remove extraneous material from the wire, while a suction head mounted on the base carries it away.

Adjustable opposing springs are attached from a point on the arm to points on the base t0 bias the arm to a central position and to permit the arm to absorb sudden differences in wire tension so that good contact is maintained between the wire andthe serrated wheel. Two stops mounted on the base limit the rotation of the arm.

Fer a more complete understanding of my invention, reference is made to the accompanying drawing in which Fig. l is a perspective view of one embodiment of my invention shown in its relation to a winding machine; Fig. 2 is an enlarged partial section of two adjacent insulated wires wound on a supporting card.

Referring to the drawing, the wire I is drawn from a reel (not shown), over the receiving pulley 2 pivotally mounted upon the insulating base 3. After threading the directional pulleys 4 and 5, it passes over the insulation scraping knife 6, the brush l, the serrated contacting wheel 8, the guide pulley 9 and is wound on card I0 by the winding machine II. Hence, the teeth of the wheel 8 are in constant contact with the moving wire. The pulleys 4 and 5 and the contacting wheel 8 are all mounted upon a tension device I2 of which the arm I3 is pivotally mounted upon the base 3 at I4. The scraping means B and the brush 1 are mounted upon the arm I3 adjacent the path of the wire.

Winding machines wind linear and non-linear resistances upon cards varying in shape from that of a linear resistance having a cylindrical form centered at the winding machine axis of rotation to non-linear resistances having overswung sections in which the axis of rotation is wholly outside the section being wound. The cylindrical card produces a uniform tension on the wire as it is wound. while the tension produced in the winding of the overswung card goes through sudden wide changes during rotation of the card. As the overswung card section moves away from the contacting device during one half of each revolution, tension is applied to the wire that immediately drops to zero as the section moves towards the device during the second half revolution and the wire reverses direction. As

, 3 the cycle begins again, tension is abruptly applied to the wire.

The drop in potential along the wire being wound is used to measure the resistance. Since the order of magnitude of this quantity is millivolts, good contact must be maintained between the wire and the serrated wheel to assure accurate results.

lStarting friction of the scraper device, and of the bearings of the pulleys and the serrated wheel, adds to the effect on the wire of the tension supplied by the Winding of the resistance wire on the supporting member. Momentum of the pulleys and the wheel when the wire' is being wound, adds to the effect of reduction of the winding tension, aiding in the effect of producing slack in the wire. Hence. each of these factors resist sudden changes in winding tension. These changes occur rapidly as the winding machine operates so that means must be supplied to absorb the shock of the sudden changes in tension. v The opposed biasing springs I5 and I6 with adjustments at I1 and I8, respectively, are at- .tached to the arm I3 at I9 and to the base 3 at 20 and 2|. Resilient stops 22 and 23, attached to the base 3. limit the movement of the arm about the pivot I4.

Inequalities in wire tension are equalized by action of the arm I3. When the force on the wire by the supporting member is momentarily increased, the point I9 against the spring I6 to absorb the tension shock caused by the increased force, plus inertia of the wheel and pulleys, that otherwise might part the wire or at least stretch it beyond its elastic limit As the stress continues, the wheel and thepulleys accelerate, decreasing the inertia effect and allowing the spring I6 gradually to restore member I3 to the normal position deter-l mined by the adjustments Il and I8. When tension in the Wire suddenly decreases, as in the case of the wire reversals of overswung cards already described, a similar action takes place in the opposite direction as momentary slack in the wire occurs and the point I9 immediately moves against the spring I5. As lthe speed of the wheel and the pulleys decreases, the spring I5 gradually returns member I5 to the nominal position.

A terminal 2l mounted upon the arm I3 is provided with a spring contact 25 in contact with the side of the wheel 8 to make continuous con- ,taet with the moving wire so that the resistance of the wire passing the wheel 8 can be continuously measured by any standard means by connection with the beginning of the wound Wire at I and the terminal wire 24'.

An air jet 26 and a suction head 2'I aid in removing the scraped material as well as any extraneous material that might cling to the wire. The scraper 6 is adjustable at 28 for thickness of its cut to bear on the wire with enough pressure to remove thel insulation without penetrating the metal. An additional adjustment may be added to move the blade sidewise to prevent gl'ooving of the edge of the blade.

The contacting device is mounted in relation to the winding machine as shown in the drawing, so that the wire turns will be wound as at 29 and 3,0 with the flat surfaces 3l and 32 pro 'vided by the scraper 6 respectively adjacent the card4 I0. This is particularly advantageous in the winding of small diameter Wires which are thereby prevented from rolling out of correct immediately moves terial from the wire surface to make good contact with the serrated wheel. The scraper has tension enough merely to ride the surface of the wire and not enough to penetrate the skin of the metal.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto, since many modifications can be made, and I therefore contemplate by the appended claims to cover any such modifications as fall Within Ithe truex spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

v1. An incremental device for the electrical. contacting of moving wires comprising an insulating base, a tension device provided with an arm pivoted on said base, pulleys and an electric conductive serrated wheel pivoted upon said base and'said arm in spaced relationto provide reverse paths for said Wire along said arm, the teeth of said serrated wheel being in contact with said wire to provide for electric conduction therebetween, a terminal mounted adjacent said serrated wheel and provided with a spring contact biased against the face of said wheel tol said arm in spaced relation to provide wire paths along said arm, the teeth of said serrated wheel being in contact with said wire to provide electrical contact therebetween, a terminal mounted adjacent said wheel, said terminal being provided with a spring contact biased to contact the side of said Wheel to provide continuous contact with said moving wire, adjustable opposing springs mounted between said arm and said vbase and positioned to cooperate with said pivotally mounted arm to produce a snubbing effect of said wire on said pulleys -and maintain a desired tension in said wire along said wire paths of said arm, resilient stops mounted. upon said base` adjacent said arm to limit the movement of said arm.

3. A device for the electrical contacting of a moving wire comprising an insulating base provided with a pulley for receiving said wire and an exit pulley for guiding said wire away from said device, a tension regulating device including an arm pivoted upon said base, a directional pulley and an electric conductive serrated wheel pivoted upon said arm in spaced relation to provide a wire path therebetween, scraping means mounted on said arm adjacent said wire path and in contact with said wire to remove a sector of insulation from said wire as it moves through said device, brush means and blower means mounted upon said arm to remove excess material from said wire after scraping,

suction means mounted on said base to receive said excess material, opposing springs mounted between said base and said arm to bias said arm to a normal position, said opposing springs, serrated wheel and pulleys being cooperatively positioned with respect to said arm to permit rotation of said pivoted arm to maintain a desired tension in said wire along said wire path, adjustment means mounted upon said springs to vary the tension thereof, stops to limit the movement of said arm and a terminal provided with a spring contact mounted upon said arm in contact with the face of said serrated wheel.

4. In combination with a winding machine for winding resistance wire on supporting cards from a reel under tension, a device for the electrical contacting of said wire comprising an insulating base, a tension regulating device provided with an arm pivoted upon said base, a serrated wheel pivoted upon said arm to provide contact with said wire, pulleys pivoted ,to said arm and said base to provide a path for said wire along said arm, adjustable opposing springs mounted between said arm and said base to absorb the shock of rapid differences in said tension communicated to said arm by said wire and to control the pivot action of said arm to maintain desired tension in said wire along said path.

5. In combination with a resistance winding machine for winding resistance wire upon supporting means, directing means for providing a path for said wire, contacting means for providing a contact for the measurement of the resistance of said wire, said directing means guiding said Wire to said contacting means and to said winding machine, said contacting means including an arm pivotally mounted upon said base, pulleys and an electric conductive serrated wheel means mounted in spaced relation upon said arm to provide a reverse path for said wire across said arm, the teeth of said serrated wheel being in constant electrical and mechanical contact with said wire, scraping means mounted adjacent said path between said serrated wheel and one of said pulleys, adjustable springs mounted between said arm and said base and positioned to cooperate with said pivoted arm to bias said arm in order to maintain electric contact between said serrated wheel and said wire, terminal means provided with a spring contact biased into relation with the side of said serrated wheel to provide contact between said terminal and said wire.

6. In combination with a winding machine for Winding resistance Wire on a supporting card, a device for the electrical contacting of said wire comprising an insulating base, an electric conductive rotatable serrated wheel to provide continuous engagement and electrical contact with said wire, a terminal provided with a spring contact bearing on the face of said Wheel, a tension regulating device pivoted to said base, opposing springs mounted between said tension device and said base to enable said tension device to absorb tension shocks communicated to said wire by said card to permit limited spring biased pivotal motion of said tension device with respect to said base to maintain said continuous electrical contact with said wire.

BENJAMIN B. SCOTT.

REFERENCES CITED The following referencesare of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,865,577 Macbeth July 5, 1932 1,992,859 Cooper Feb. 26, 1935 2,069,623 Pickhaver et al. Feb. 2, 1937 2,219,196 Nystrom Oct. 22, 1940 2,353,639 Berthold et al July 18, 1944 2,401,676 Weber June 4, 1946 FOREIGN PATENTS Number Country Date 661,959 Germany June 2, 1938

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