US384323A - mallett - Google Patents

Description

(No Model.)

B. J. MALLETT.

AUTOMATIC POLE CHANGER.

No. 384,323. Patented June 12, 1888.

IN VEJVTOR WITNESSES.

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IDDYVARD J. MALLETT, OF NEN YORK, N. Y.

AUTOMATlC POLE- CHANGEP.

EPECIPICATION forming part of Letters Patent No. 384,323, dated. Juli 12, 1888.

Application filed April 5, 1888.

T0 (til whom it 11mg concern.-

Bc itknown that I, EDWARD J. MALLETT, of the city, county, and State of New York, have invented a new and useful Improvement in Automatic lole- Changers and Polarized Magnets, of which the following is a specification.

in obscrvi ng the operation ofautomatic polechangers I have found that the speed of vi bration of. the automatically-vibrating polarized armature is directly proportionate to the quantity of current which passes through the contacts of such armature and inversely proportionate to the quantity of current which acts with permanentinduction on the armaturc. If, therefore, there be a division of the cnrrentsupplyingsuch a magnet, so that a part shall: pass through the contacts and a part shall act with permanent induction upon the armature, the relations between these two divlslons of the current will be maintained, and theraieof vibration ofthcarrnature will beuniform, notwithstainling variations in current strength, because these variations affect proportionately each division of the current.

The division of the currentjust referred to can readily be obtained by the use, in connec tion with the coil or coils in circuit with the contacts, of a coil included in a permanentlyclosed derived circuit thereto. This derived clrcuitcoil acts with permanent induction upon the armature and maintains it in polarized condition. The degree ofpolarization is determined by the quantity of current passing through the derived circuit'coil. If, there fore, the relative resistance of this circuit to that of the circuit which includes the contacts be adj ustcd so as to obtain a field of the proper character, this adjustment, when once made, will be maintained, notwithstanding variations in battery or current strength, because both divisions of the cnrrent,being proportionately affected by such variations, will preserve their relations to each other unchanged.

In Figure 1 of the accompanying drawings 1 have illustrated to some extentdiagrammatically a polechanger and circuit-connections therefor embodying the invention. Fig. 2 is a diagram of modification which will be hereinafter explained.

The automatic pole-changer shown in Fig. 1 is substantially the same, in a general way, as that described and claimed in my applica- Serial No. ZGSWS L (No model) tion for Letters Patent filed November 19, 1885, Serial No. 183,264, comprising, as it does, the combination of an elcctromagnct, an induced magnetic armature therefor pivoted over such magnet and between its poles, and contact-points controlled thereby, the magnet and the contacts being in the circuit to be reversed. So far as this feature is concerned, the only difference between the device. shown in my present application and that shown in my aforesaid prior application is that in the latter I have represented a two contact polechanger with a split battery and the appropriate circuit-conuections therefor, while in thcprcsent case I. have represented a fourcontact pole-changer, a single unspiit battery, and the circuit-connections appropriate for such an organization. Both types, however, are well known in the artand arcinterchangeable.

In the present instance A A are the spools or coils of the magnet in circuit with the contacts. and B are their cores affixed to a yoke, (l. [let-ween these two spools A, i place a third spool, D, whose core F is also fixed at one end to the bark yoke, (I. To the other end of this core E is pivoted at its middle the armature l? in such position that its ends overhang the cores 13 of the main electro-magnet. From the middle of armature i evl'ends upward standard 0, having at its upper end two contacts, a. a, projecting laterally one from each side of the upright (l. Contacts o aarc the movable contacts. Above them are the two corresponding fixed contacts, 7) i), supported in the usual way by a bracket or by some suitable part of the framework of the instrument. Supported also upon the framework of the instrumentare two leaf-spring contact-strips, c c, which are so set as to normally press toward each other and against the contiguous contacts a Z) and a b.

The eircnit-connectionsare as follows: From one pole of batteryX by wire 1 to the upright G, which is electrically connected to contacts a a; from the opposite pole of the battery by wire 2 to the stationary contacts I) I); from one contactstrip, c or c, by wire 3 through the spools A A of the main eleetro-magnet, and thence to the opposite contact-strip.

In the circuit I have indicated at Y a polar ized escapement typical of any number of printing or other instruments, which may be placed in the circuit to be operated by reversals thrown thereon.

In the position in which the parts are shown in the drawings the armature has been attracted in such direction as to move the upright G to the right, thus causing a to contact with strip breaking the contact between 0 and b and a and c, and permitting a to contact with b. The circuit under these conditions is from one pole of battery by wire 1, upright G,

contact a, strip 0, wire 3, through the spools A, thence by continuation of wire 3 to contactstrip 0, contact 2), wire 2, back to the opposite pole of the battery. The connections are such that when the current passes in this direction it gives such polarity to the main electromagnct that the armature is attracted to the left, breaking the contacts at a c and ab, and closing them at a c and c I), thus reversing the polarity of the circuit and causing the armature to be again attracted to the right, and so on. Thus far there is in the circuit-connections nothing essentially new beyond what is u disclosedin my priorapplication, hercinbefore referred to.

With a view to inductively magnetizing the armature, I connect the spool D with the bat tery X in derived circuit to that in which the spools or coils A are included, this derived circuit connection being shown at 4.

The character of the field ot' the pole-changer is determined by the distribution of the ourrent between this derived circuit and the main circuit, only such proportion being allowed to pass over the derived circuit as is required to inductively magnetize the armature to the extent necessary to produce the best results. When once this is ascertained and the circuits are adjusted accordingly, the relations will be maintained for the reasons before indicated, notwithstanding variations in current strength. For my purpose I have obtained very satisfactory results by interposing in the derived circuit a resistance, R, of two hundred ohms, the resistance in this instance of the two spools A of, the main electro-magnet being two and onc'half ohms each, and that of the armature spool D being forty ohms. In this way the instrument can be adjusted so as to be extremely sensitive and to respond with great rapidity and certainty, while the adjustment when once made will be retained, notwithstanding variations in battery or current strength.

I am not limited to the use of this invention with a polarized magnet of the particular form shown in Fig. 1. Any form of polarized magnet in which the armature is inductively magnetized by an electric current in lieu of a permanent magnet may be employed. For instance, in Fig. 2 I have represented a form of polarized magnet in which there are two cores and spools only, instead of three, as in Fig. 1.

The magnet-cores are represented typically at B. The one winding A corresponds to the like designated part in Fig. 1, and is in circuit with the armature-contacts. The other winding D corresponds in function to the similarlylettcred part in Fig. 1, and is in the permanently-closed relatively-high-resistance derived circuit 4. The magnet H, thus influenced by the coils D, forms a field by means of which the armature F is permanently magnetized by induction, and this although the armature is pivoted (as indicated in the figure under consideration) on bearings which are electrically and magnetically independent of the other parts of the instrument. The arrangement of circuits, contacts, &c., is the same in this figure as in Fig. 1.

Having now described my improvement, what I claim herein as new and of my own invention is as follows:

An automatic pole-changer which contains two coils or sets of coils, the one in circuit with the contacts of the pole-changer, the other in a permanently-closed circuit in derivation thereto, whereby a division of the current supplying the pole-changer is effected, a part passing through the contacts and a part acting with permanent induction upon the armature, substantially as and for the purposes hereinbefore set forth.

In testimony whereof I have hereunto set my 5

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