US1500082A - Electric-current regulator - Google Patents

Description

July 1 1924. 1.500,082

w. LANGD'ON-DAVIES ET AL ELECTRIC CURRENT REGULATOR I I the Patented July 1, 1924.

UNITED STATES WALTER LANGDON-DAVIE-S AND ALFRED SOAQVIES, OF LONDON, ENGLAND.

ELECTRIC-CURRENT REGULATOR.

Application filed February 27, 1922.

To all whom it may concern:

Be it known that we, WALTER LANGDON- DAVIES and ALFRED SOAMES, subjects of the King of England, and both residing at London, in England, have invented certain new and useful Improvements in Electric- Current Regulators of which the following is a specification.

This invention relates to electric current regulators particularly suitable for use in alternating current circuits and has special reference to regulator's which comprise two relatively movable mutally inductive circuits in which the automatic relative movement varies the choking effect on the circuit or alters the, ratio of transformationthus controlling the'voltage or current in the working circuit.

The specification of our application for United States Letters Patent Serial No. 309,27 9 describes a construction of regulator of this general type in which the two mutually inductive circuits are in the form of coils wound upon magnetisable cores arranged so that although one coil and its core can rotate partially relatively to the other, the reluctance of the magnetisable circuit remains substantially constant. The rotation of the movable coil and its core is in this. previous construction so controlled that those members remain stationary until the current reaches a predetermined value and then move into such a position as to keep the current constant.

The regulator according to the present invention may be of similiar construction so far as the coils and their cores are concerned but the control is different for it is found in practice that in certain circumstances, for instance in arc welding, less mechanical control is advantageous in the initial position of the regulator provided that the maximum movement of the movable coil is limited.

Therefore according to the present invention, a stop or similiar device is provided which will prevent the regulating action from proceeding beyond a definite amount. This limit is preferably variable in order to suit the working conditions and such variability may be secured by provid ing s'ay'a' series ofhol'e's in any one of which a stop may be placed to prevent further movement of the movable coil. Thus as movable member moves from its 7 original position, it introduces impedance Serial No. 539,568.

- or otherwise controls the current in the working circuit until it reaches the stop. In this position the impedance in the circuit will be that most suitable for the workmg conditions, and under normal working conditions the regulator will remain at or about this position. It will be understood that if an operation such as arc welding is being carried on, the action of the regulator at its limited maximum position will be such that no very bad effect will be obtained even if the working circuit is sho'rt-circuited.

The provision of this stop whose position is preferably variable, is an essential feature of the present invention but it is convenient to furnish the regulator also with some device which will act to prevent its movement being too sudden. Such a device may be a dash pot or its equivalent and in some cases it may be arranged to act strongly in one direction only. It is however to be understood that this one way retarding device is not essential to the present invention and that in some cases no separate retarding device need be used, the inertia of the moving parts thems lves being suficient.

The improved regulator is conveniently provided with some means for bringing the movable part back to its original position. This arrangement may be a light spring or weighted arm exercising suiiicient force for its purpose but not primarily or necessarily acting to an extent su'flicient to keep the. current constant after the movement of the regulator has started.

As above mentioned the general construction of the improved regulator apart from its controlling arrangements may be similar to that described in our prior specification Serial No. 309,27 9, the relative movement of the two coils being rotary and the magnetic circuits such that the reluctance remains substantially constant. The windings may act as a transformer or as a choke coil.

In addition to the arrangement of coils mentioned in that prior specification, al ternative arrangements are possible. In one such alternative, instead of the two coils being in series as in the example shown in Figures 2 and 4e of the drawings accompanying our prior specification Serial No. 309,279, the working circuit may include one coil only, and the other coil may be a winding' short-'circuited on itself.

In the. other alternative although the two coils may be in series With the working circuit, they may have an unequal number of turns. The effect of this is to introduce a certain amount ofchokes or impedance into the circuit independent of the position of the regulator. Such independent choking effect if required, may however be introduced by inserting a separate impedance in another part of the circuit.

In the accompanying drawings,

Figure 1 is a perspective view showing one construction of regulator according to this invention,

Figure 2 is a similar view with the cover removed,

Figure 3 is a diagram showing the electrical circuit of the regulator.

For the sake of clearness it is convenient first to refer to Figure 3 which shows the two magnetisable cores A and B provided with windings C and D after the manner of the stator and rotor of an induction motor. The general arrangement of the cores and their coils is similar to that described in the specification of our application for United States Letters Patent Serial'No. 309,279.

On the shaft B (Figure 2) of the rotor member B is mounted a pinion E the teeth of which engage with those of a quadrant on a lever F pivoted as at F to afixed arm or bracket G. To the free end of the pivoted lever F is pivoted a link or connect ing rod H joined at its lower end to the plunger J of a dash pot J.

The initial position of the regulator is determined by a stop K (Figures 1 and 3) against which restsan arm L attached to the shaft B. In the diagram forming Figure 3, the stop K is shown in such a position that. the rotor B and its coil '1) are given a slight lead relatively to the stator and its winding so that in operation the rotor will tend to turn in a counter-clockwise direction. The amount of this lead may be varied by moving the stop K which as shown in Figure 1 may be in the form of a stud which can be shifted in a curved slot M in the cover M. Only a comparatively' light controlling force is required which in the construction shown in Figures 1 and 2 is provided by a spring N having one end fixed and the other attached to a small pulley B on the rotor shaft B.

The amount of rotation of the rotor memher is limited by a stop 0 the position of which may be varied as indicated for instance at the three places marked on Figure 3. In practice the stop is conveniently in the form of a stud and hand wheel nut which can be moved to any desired position in the slot M as shown in Figure 1. i

In Figure 3 the two windings C and D are shown joined in series in the working circuit which by way of example is illus trated as arranged for electric welding. In

the initial position the amount of impedance or choking effect is slight for the magnetisation of the iron circuit produced by the one coil is practically neutralised by the other coil, the only efi'ective flux, supposing the number of turns in the two coils to' be equal, being due to the slight lead given to the rotor. When the current is switched on the rotor turns in a counterclockwise direction but its movement is prevented from being too sudden by the dash pot J. As it turns the choking effect gradually increases until further movement of the rotor is prevented by the arm L coming into contact with the stop 0 whose position has been arranged so that the choking efi'ect in that position is most suitable for the conditions under which the regulator is working.

It is sometimes desirable to arrange for the return movement of the rotor member to be as free as possible and this can be done for instance by providing some known form of valve indicated diagrammatically at J in Figure 2 inthe plunger J of the dash pot. V

It is to be understood that the'mechanical details of the construction shown in Figures l and 2 are given by way of example and that they may be varied without departing from the spirit of this invention.

l/Vhat we claim as our invention and desire to secure by Letters Patent is 1. In an automatic regulator for alternating current arc welding circuits, in combination, a stationary magnetizable core, a second magnetizable core partially rotatable relative to the fixed core without altering the reluctance of the magnetic circuit, a winding on each core, said windings being in inductive relationship with each other and connected in the welding circuit, an arm on the rotatable core, an adjustable stop in the path of motion of said arm and means for preventing rapid movement of the arm in the direction of said stop, but allowing it quick return.

2. In an automatic regulator for alternating current arc welding circuits, in combination, a pair of relatively rotatable magnetizable cores, a winding on each core connected in the welding circuit, adjustable means for setting the amount of lead, an adjustable stop for detenninmg the amount of relative rotation, means for retarding the rotation in one direction but assuring rapid rotation in the other direction.

3. An automatic regulator for an alternating electric current circuit comprising in combination, a stationary magnetisable core, a winding thereon, a second magnetisable core partially rotatable relatively to the fixed core without altering the reluctance of the magneticcircuit, a winding on the partially rotatable core in inductive tel?" tionship with the Winding on the fixed core, an arm moving with the partially rotatable core, an adjustable stop in the path of motion of said arm, a pinion rotating With 5 the partially rotatable core, a dash pot, a

plunger for said dash pot connected to the WALTER LANGDON-DAVIES. pinion by means of a pivoted toothed quad- ALFRED SOAMES.

rant, and a valve in said plunger to allow for its quick return movement.

In testimony whereof We have signed our 0 names to this specification.

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