US1977697A - Control apparatus - Google Patents

Description

Oct. 23, 1934.

G. H. RocKwoOD 1,977,697 l CONTROL APPARATUS Filed oct. 23, 1929 Patented ct.- 23,` 1934 UNITED STATES PATENT OFFICE 1,911,691 comm. APPARATUS GeorgeRBoekwoolmParLllLassig-norto Western Blech-ie Company, Incorporated, New York, N. Y., a corporation of New York Application October 23,

SGaim.

5 of a simple and eilicient measuring or controlling apparatus.

In accordance with one embodiment, the invention contemplates the provision of 'apparatus for winding resistance wire about a mandrel to form I l a resistance coil and simultaneously measuring the resistance of the coil by connecting it in an arm of a Wheatstone bridge circuit. When a predetermined amount of wire has been wound on the coil, the bridge circuit will be unbalanced l in -a direction opposite to its unbalanee when less than the predetermined amount is wound ther-con and current will flow from the bridge through a transformer to increase the voltage before directingitfothegridofavacuumtube. The

Nvacuum-tubeisof atypewhereinifthegrid voltage thereof is more negative than the plate voltage divided by the amplification factor oit the tube no plate current will iiow and if the grid voltage is less negative than this value the plate current is determined bytheplatevoltsgeand the resistance in the plate circuit.

The plate circuit of the vacuum tube is connected to a. control relay which is effective to complete a circuit to an electromagnetically operated knife and an electromagnetically operated brake. Upon the reversal of the direction of iiow of current across the bridge circuit the grid voltage will immediately become less negative than the plate voltage divided by the ampliiication '35 factor ofthe tube thereby causing an ampliiled flow of current in the platecixcint of the tube and the consequent operation of the control relay, which will complete circuits to operate the knife and the brake, severing the strand which is passing under the knife and interrupting the rotation of the spool from which the strand of wire is being drawn.

A clear understanding of the invention will -be had by reference to the following detailed description taken in conjunction with the aeeom' panying drawing, wherein a single schematic view shows diagrammatically the featmes thereoi' and wherein like reference numerals designate the same parts.

The numeral 1 designates a supply spool from which a strand 2 of resistance wire is drawn overgmdes3and4toarotatingfiattypecoil base 5. Thebaseispositlonedbetweenachuek B'rotated by a motor 10 and a freely rotatable chuck 11. Theforwauiendofthewixemaybe 1929, Serial No. 401,947

attached to the chuck 6 by means' of a clip 12 provided therefor. y

A knife 13 cooperates with the guide 3 to form a shearing mechanism which is designed to be actuated by .an electromagnet 14, the armature 15 of which engages a slot 16 in the knife. The

armature is normally retained in the position shown by means of a spring 20 which tends to rotate it about a pivot 21 provided therefor. When the lcuife 13 is actuated to sever the wire, the spool 1 would nomially-continue to rotate due to its momentum so there is provided a brak-- ing mechanism therefor designated generally by the numeral 22 and comprising an electromagnet 23 having an armature 24 pivoted at 25 and carrying on an-arm thereof a braking member 26 which, upon energization of the electromagnet 23, will engage the periphery of the spool and its rotation. I

The motor l0 is connected to a source of electxonwtive force by means of a dou-ble pole switch 30 which when closed completes a circuit from a. line conductor 31 through conductors 32, 33, and. 34 "to the motor and from the motor through condoctors 35, 36, and 37 back .to the other side of the line at 38. In the particular embodiment of the invention disclosed herein, the conductors 31 and 38 are supplied with direct current at 110 volts.

when closed, the switch 30 also completes a circuit from the line conductor 31 through the conductor 32 and a conductor 40 to the winding of a. relay 41 and through the winding of the relay, a conductor 42, and the conductor 37 back to the line at 38. lThe relay 4l will thus be energized simultaneously with the starting of the motor 10 and will attract its armature 43 to complete circuits t0 be described in detail hereillafter. A relay 44 is also' connected to the conductors 33 and 36 and will be energized when the switch 30 is closed. This relay is made to respend slowly to the current supplied thereto by connecting an'impedance coil 45 in a lead 46 connecting one side ofthe winding of the relay to the conductor 33 and by connecting a resistance coil 50 between the lead 46, at a point intermediate the impedance coil 45 and the relay 44, and a lead 51 which connects the other side of the winding of the relay 44 to the conductor 36. The relay 44, upon being energized, acts slowly to attract an armature 52 associated therewith and close two contacts 53 and 54 to connect a. conductor 55 to a pair of conductors 56 and 57, respectively. The. conductor 55, in the particular embodiment disclosed herein, is connected lic to a source of direct current at 48 volts. A pair of xed condensers and 61 are connected be tween the leads 56 and 57, respectively, and the line conductor/55.

When the switch 30 is closed manually the motor l0 will be started, the relay 41 will be energged, and immediately thereafter the relay 44 will close the contacts 53 and 54. The energization of the relay 41 will close a contact at 62 to connect a lead 63 running to one end of the secondary winding of a three winding transformer 64, the other end of which is connected to ground at 65, to a lead- 66l connected to a Wheatstone bridge circuit designated generally by the numeral 67. The energization of the relay 44 will connect the line conductor 55 through theconductors 56 and 57`to movable contacts 70 and 71, respectively, of a relay 72 which, upon being energized in a manner to bedescribed more in detail hereinafter, will move the contacts 70 and 71 into engagement with a pair of stationary contacts-73 and 74, respectively. Connected to the stationary contacts 73 and 74 are a pair of conductors 75 and 76 which are connected to one end of the windings of the electromagnets 23 and 14, respectively. Shunts 77 and 78 connect the conductors 56 and 57 to the conductors and 76 through condensers 79 and 80, respectively. The other terminals of the windings of the electromagnets 23 and 14 are connected through conductors 81 and 82 to the other side of the 48 volt direct current line; Thus, the energization of the relay 72 will cause the actuation ofthe electromagnets 1'4 and 23, which will thereupon sever the wire and sto the rotation of the spool 1.

The transformer 64, which supplies electrical energy to the Wheatstone bridge circuit, has its primary winding connected by conductors 83 and 84 to the output of a voltage regulator 85 which is connected to line conductors 86 and 87 which supply 110-volt, 60-cycle alternating current thereto. This transformer also supplies` current to a filament of a vacuum tube 91 through conductors 92 and 93-connected to a secondary winding thereof, a lead 94 from which is connected to the movable contact of'a potentiometer 95.

The potentiometer 95 is connected to the line conductors- 86 and 87 by conductors 96 and 97, respectively, which are in -turn connected to one end of the secondary winding of a transformer having a high impedance ratio and through a resistance 101 to the relay. 72 by conductors 102 and 103, respectively. The other end ofthe winding of the secondary of the transformer 100 is connected to a grid 104 of the vacuum tube 91 through condenser 105 which is shunted by a resistance 106. The other end of the..winding of the relay 72 is connected by a conductor 107 to a plate 110 of a vacuum tube 91 and the conducbridge, and across the. bridge to a point 113 thereof which is connected to ground at 114.

l Arms 115 and 11s of the Wheatstone bridge s1 are of equal resistance, and arm 117 is of known ristance and may be varied while the wire between the guide 3 and the clip 12 forms the fourth arm of the Wheatstone bridge. To include the wire between these points in this arm of the bridge a brush 120 contacts with the chuck 6 andv is connected to ground at 121 by a conductor 122 and the guide 3 is connected to a point 123 of the Wheatstone bridge by conductors 124 and 125. The point 126 on the bridge opposite the point 123 is connected to one end of the primary winding of the transformer 100 by a conductor 127 and the other end of the primary winding of the transformer 100A is connected to the point 123 by the4 conductor 125.

The apparatus and circuit for controlling the mechanism having been described in detail, a clear understanding will be had by referring to -the following description of the operation thereof: The resistance of arm 117 is adjusted to that desired in the finished resistance coil, and a strand of wire 2 is drawn from the spool 1- and connected to the clip 12 on the chuck 6, passing over age to the Wheatstone bridge circuit 67. Shortly f after the relay 41 operates the relay 44, which is also controlled by the closing of the switch 30, will be energized and will attract its armature 52 to close the contacts 53 and 54. The closing of the switch 30 and the consequent actuation of the relay 41 applies the voltage tothe bridge circuit and may cause a switching transient current in the circuit as a whole, which will cause the relay 72 to be operated momentarily. However, since the slow acting relay 44 does not close until an appreciable time after the relay 41 has attracted its armature, such a transient current will be dissipated before the circuits are com- 1 pleted to supply power to the electromagnets 14 and 23. Upon energlzation of the relay 44 power will be placed upon the open contacts 70 and 71 so that when the relay 72 is subsequently energized.l the brake 22 and the knife 13 will be 120 that of the arm 117. However, when the desired amount of lresistance is reached inthe coil being wound the flow of plate current in the tube is established to cause the relay 72 to operate, whereupon the brake and knife will be actuated. While in the specic embodiment of the invention disclosed herein the coils being wound are formed of uninsulated wire, it is to be understood that coils of insulated wire might also be formed by simply adapting the apparatus described above so that a coil having a length of wire greater than necessary to form the resistance required could be wound and thereafter unwound and simulta- .neously scraped of insulation while in contact with a guide member 'similar to the Aguide member 3, appropriate changes in the circuit connections being made so that the plate current of the tube would beging to flow as soon as the resistance of the coil being measured became less than a predetermined amount rather than more than a predetermined amount as disclosed herein.

What is claimed is:`

1. In apparatus -for handling strand material, means for winding a strand, a Wheatstone bridgecircuit, Imeans for continuously including thewound strand as the unknown arm of the Wheat- 1' stone bridge circuit, a thermionic valve, means for establishing a f'low of current in the plate of the valve under control of the potential in the grid of the valve and in response to a change in the direction of flow of current across the bridge, and means controlled by the thermionic valve for severing the strand when the resistance of the Wound strand constituting the unknown arm balances the bridge circuit.

2. In apparatus for winding resistance coils, means for advancing a strand and winding it into a coil, a xed contact member positioned adjacent the path of the strand during its advancement, a Wheatstone bridge circuit, means for including the portion of the strand positioned forwardly of the contacting member as an arm of the Wheatstone bridge circuit, a thermionic valve responsive to a change in resistance of the portion of the strand positioned forwardly of the contact member and operative upon a change in a direction of flow of the output voltage of the bridge, and means controlled by the thermionic valve for severing the strand when the resistance of the advanced strand constituting the unknown 1' arm of the bridge circuit balances the bridge.

3. In a measuring apparatus, a winding arbo a terminal upon the winding arbor for receiving the forward end of a strand to be wound upon said arbor,a cutting. knife, a bridge circuit having three arms of known resistance, means for engaging the strand adjacent said cutting knife. means electrically connected to said strand engaging means and said terminal for continuously including the strand therebetween as the unknown arm of the bridge circuit. and means actuated when the wound strand balances the bridge circuit for actuating said cutting knife for cute ting the strand.

4. In a measuring apparatus, a supply spool of strand material, means for vrotatably supporting i said spool, a winding arbor for winding the strand from the spool, a terminal disposed upon said winding arbor for receiving the forward end of the strand, a cutting knife, a bridge circuit having three arms of known resistance, means for engaging the strand adjacent said cutting-knife, means electrically connected to said engaging means and said terminal for continuously including the strand therebetween as the unknown arm of the bridge circuit, means actuated when the wound strand balances the bridge circuit for actuating the cutting knife for cutting the strand. a brake, and means for actuating said brake for stopping the rotation of said mipply spool upon the actuation of said cutting knife.

5. In an apparatus for handling strand material, means for advancing a strand of material,

a nxed material engaging member positioned adjacent the path of the strand during its advancement, a severing element positioned adjacent said mem means for measuring the resistance of the strand positioned forwardly of said member, and means controlled by said measuring means for actuating said severing element when the resistance of the measured strand has reached a predetermined value for severing the strand.

GEORGE H. ROCKWOOD.

Ill)v

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