US1645150A - Apparatus for controlling the flow of current from direct-current generators - Google Patents

Description

1,645,150 Oct. 1927. w NN APPARATUS FOR CONTROLLING THE FLOW OF CURRENT FHOM DIRECT CURRENT GENERATORS Fi] ed Nov. 24, 1925 INVENioR.

Patented Oct. 11, 1927.

UNITED STATES P'ATE'NT OFFICE.

SEXVARD W. MANN, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO I-I. KLEINHANS COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

APPARATUS FOR CONTROLLING THE FLOW OF'CURRENT FROM DIRECT-CURRENT GENERATORS.

Application filed November 24, 1925. Serial No. 71,154.

My invention vrelates to means for controlling the flowof current from direct current generators,and is particularly adapted to circuits in which the resistance of the consuming element varies widely at each operation, as in arc-welding,

In general, this invention has the same objects as that shown and describedin my applicationSerial Number 735,310, filed September 2,1924; but, more particularly,

its main object is to provide the system containing the principles of that application with a switching means whereby the system can be set for, the consumption of'certain amounts of current and the amperage for any setting will remain substantially constant irrespective of variations of resistance in the current-consuming means. This and further objects will ,be explained hereinafter in detail. 1

The accompanying drawing shows the generator system diagrammatically, the switching means being shown partly diagrammatically and partly in plan view.

On the drawing, 1 designates the armature of a direct current generator,having two leads 2 and 3 with their outer ends connected to some translating or currenteconsumingdevice, such as the arc welding terminals 4 and 5. The lead2 preferably includes as a part thereof a reactance coil 10, While the lead 3 has interposed therein more or less of a resistance 9 .and a switching means presently to be described; The latter lead connects one brush of the armature ,1 to one terminal of the resistance 9, and the wire 8 is connected at one end to-the welding electrode 5 and at theother end to the movable switch arm 12. w

The resistance 9 containsthree sections 13, 14 and 15, but may contain more or less. The section '13 comprises the two parallel conductors or bus-barsf16 and .17 between which are three resistance wires 18. The section 14 comprises two parallel conductors or bus-bars, .onebeing marked 19 and the other being an extension of the bus-bar 17.

Two resistance wires 20 are connectedto the.

bus- bars 17 and 19. The section 15 com prises two parallelconductorsor bus-bars one being marked 21 and the other being a prolongation of the bus-bar 19. A resistance wire 22 is connected to the bus- bars 19 and 21. The particular resistance shown illustrates onlyone of many kinds of resistances which might'be employed. The number of resistance wires bridging the busbars of the individual sections will vary in accordance with the demands of the work to be done. The wire 3 is shown connected to the bus bar 16. V

I provide the movable Switchblade or member 12 which is pivoted to swing in two planes at right angles to each other. 22 is a shaft or pivot carrying the block 23 in whlch one end of the switch member 12 is pivoted by means of the pin 24 extending through the block 23 and the member 12,

the pin 24 being at right angles to the pivot 22. The blade of the switch is adapted to engage anyone of the pairs of contacts 25, 26, 27 and28.- The lead'3 is electrically connected to the contact 25through the wire 29. The wire 30 connects the bus-bar 17 to the contact 26; the wire 31 connectsthe busbar 19 to the contact 27; and the wire 32 connects the bus-bar 21 and the contact 28..

The switch member 12 carries a blade or contact 33 insulated therefrom. This blade engages the contact 34 when the switch the wires 18. The .contact35 is connected .adjustably by the wire 44 to a point, as 39,

in another one of the wires 18. The contact- 36 is adjustably connected by thewire 45 to a point, as 40, in one of the wires 20 The contact 37 isadjustably connected by the wire 46 to a point, as 41, in the wire 22.

A wire 42 connects the blade 33 toone terminal ofthe field winding 6, and the wire 11 connects the other terminal to a-selected point, as 7, on the lead 2, or to.a point on the reactance 10, v p a If the switch member 12 is moved: to position a,in which it engages the contact current will flow from thearmature 1 throughthe lead 3, the wire 29, the consame time, the field current-flows from the 25, and the contact 33 engages the contact 34, Y

armature through the lead 3, a portion of one wire 18, the wire 48, the contact 34, the blade 33, the wire 42, the field winding 6, the wire 11, the lead 2, and the reactance 10 back to the armature 1. 7

Let it be assumed that 800 amperes will flow in the load circuit during a welding operation. The points or connection of the field circuit to the load circuit and the amount of resistance in the field circuit are so chosen that no matter whether the welding electrodes are directly in contact with each other oran arc of anysize is drawn between them, a current of 300 ainperes flows in the load circuit. This uniformity of current flow is due to the fact that the field is strengthened or weakened in proportion to the voltage drop across the welding electrodes caused by changes in resistance between the electrodes.

If it is desired to Weld with a current of lower amperage, as 200'ainperes, the switch 7 member is moved to position b in which all sortedin the load circuit. "resistance bet-ween the armature and the theresistance wires 18 of the section 13' are inserted in the load circuit, and at thesame time a larger resistance has been introduced into the field circuit by the wire 4a connected at the point 39 on oneoi the re sistance wires 18. The point 39 of connection of the wire 30 is selected so that the field will be strengthened or weakened proportionately with the voltage drop between the Welding electrodes. When the points of connection of the field circuit have been properly selected, the current between the electrodes will be 200- arnperes when the arc is struck, and whatever the size of the arc.

If'i-t is desired to weld with 100 amperes,

the switch member is moved toposition 0 in which all thesection' 13 and a part ofthe section 14 are inserted in the field circuit, and all of the sections 13"and 14 are in- The amount of points of connection of the fieldcircuit to the load circuit, and the amount of resistance in the field circuit are so selected and field in the proper amounts to cause a con; stant flow of 100 amperes in the load cir- V cuit.

i "If a welding current ofBO amperes is de sired, the switch member-12 ismoved topositi'ondin which all or the resistance sections are placed in the load circuit, and the sections 13 and 142 and apart of the section 15 are placed in the field circuit. This resi'stance being properly :chosen, the current flowing through the electrodes will be held at 30' amperes whatever the resistance ma be between'the electrodes. 1 By' employing the several resistance sections the welding can be done at lower values of current more easily, due to the reserve Bymoving the'switch member 12 to position 0, still more resistance, for example, a drop of'i'ourinore volts, is introduced, which gives nvolt drop or reserve voltage t 8' assist the flexibility of the arc.

By moving the switch member 12 toposi tion d another'section ofresistance, giving an additional drop or two volts, is introduced, which givesa total voltage drop of twelve volts, wvhich makes the welding at exceptionally low current values very easy.

- The making of the welding easier at the different lower values of current is due to the introduction 01 additional resistance into the'circuits, which causes the generator to operate at a higher voltage.

I claim I f 1, l 1. In an apparatus for'rcg-ulating the fiow of current. from a direct currentgenerator through a translating device subject to widely varying current consumption, a shunt field winding for the generator, resistance for the load and fieldcircuits, a switch forclosing both circuits in a plurality of selective settings -to vary said resistances, and connections whereby whenv the said cir'- cuitsare closed by thesaid switch, resistance in the said circuits is so proportioned that, at any setting of the switch, field strength willbe such as to cause asubstantial'ly constant current to flow in the load circuit irrespective'of variations in the resistance of said translating device. 1

2. In an apparatus for 'regulatingthe flow of current from a direct current generator through a translating devicesubject to widely varying currentconsumptmn, a shunt field wlndingfor the: generator, resistance for the load and field circuits, switching means forclosing'each of the circuits in a plurality I of selectivesett ings to var-y said resistances,

and connections whereby when the said cir-v cuits are closed by the said; switching means, 'resistance 'in the said circuits is so proportioned that,at any setting of theswitching means, field strength will be such. as to cause a substantially constant. current 'toflow' in 'the load circuit irrespective of variations in the resistance or said tIflIlSl'2Ll3lIlg.Cl6V1C8.g

3. In; an apparatusfor-regulating the flow ofcurrent. from a: direct current generator through a translating device subject to wldelyvarying current consumption, a shunt 'fieldwindlng'for. the generator, resistance for the load and field circuits, switching as to cause a substantially constant current means to selectively set the resistance in the to flow in the load circuit irrespective of 10 load circuit to give any one of a number of Variations in the resistance of said translatpredetermined Working load currents, ing device. I

5 switching means for correspondingly selec- Signed at Pittsburgh, Pa, this 12th day tively setting the field resistance in such of November, 1925. predetermined amount With relation to the 7 load circuit resistance in any setting thereof SEl/VARD W. MANN.

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