US 393132 A
Description (OCR text may contain errors)
P. O. WAGNER.
No. 898,182. Patented Nov. 20, 1888.
N. PETERS. PhMn-Lxihcguphcr. WaihinglamD.C.
UNITED STATES FRANK C. \VAGNER, OF
ANN ARBOR, MICHIGAN.
SPECIFICATION forming part of Letters Patent No. 393,132, dated November 20, 1888.
A mlication filed August 1'22, 1888.
To all whom it may concern:
Be it known that l, FRANK C. WAGNER, a citizen of the United States, residing at Ann Arbor, county of XVashtenaw, and State of Michigan, temporarily residingiu the City of Mexico and Republic of Mexico, have madea new and useful invention in Electric Meters, of which the following is aspecification.
My invention relates to that class of devices for measuring electrical currents through the agency of heat created by the passage of the current through the instrument which measures and records the current strength, and is therefore applicable alike to the measurement of both direct and alternating currents of electricity.
To this end it consists in the apparatus hereinafter described, and particularlypointed out in the claims which follow this specification. It will be fully understood by those skilled in the art to which it relates by referring to the specification or description which follows, when taken in connection with the accompanying drawings, in which Figure l is a side elevation of my improved meter, showing a part broken away to better disclose the interior mechanism of the device. Fig. 2 is a plan view thereof, and Fig. 3 is a detail view of the circuit-changing and stepby-step attachments, while Figs. 4, 5, and 6 are detail views of the thermal bars and their immediate connections.
D is the base of the instrument, having a standard, S, at one end attached thereto, which in turn supports the thermal controlling-bar A.
M represents the meter or register attachment, similar in its general construction to recording-meters of this general type-such as gas-meters, &c.
B 13 are the binding-posts for attaching the wires which carry the current to be measured.
The thermal bar A is composed of two highly polished bars of steel or analogous elastic conducting material, H L, and a highlypolished central strip of copper, a, insulated from the two steel strips by paper strips 6 e, the object of the paper strips being to insulate the strips or bars H L from each other. The interior surfacesjof bars or strips H L are polished, as is also the copper strip a, to prevent transference of heat as far as possible. This Serial No. 283,499. (No model.)
composite bar is fastened rigidly to the standard S by screw and nut, as shown, and its free end carries a cap, G, of india-rnbber, glass, or other insulating material, held firmly in place by a pin, N, so as to prevent any relative change of position due to the heat action on the bars H and L. The free ends of the bars H and L are connected by a flexible conductor, '10, with binding-posts B, binding-post B being connected directly to mercury-cups M and M, respectively.
B is a tilting beam carried by an arm, F, and pivotally connected to the shaft V at T. (See Figs. 1 and 3.) On the ends of this beam are metallic arms Y Y, adapted to dip into mercurycnps M M and M M, according to the position of the beam.
B" is a bifurcated arm, the bifurcations of which extend over the end of the rubber cap or sleeve C. This arm is fixed rigidly to the shaft 'V and carries two pawls, ,1 f, at its i nner end, adapted to propel the ratchetwheel w and pinion p and through them the train of gear controlling the recording-meter M.
E is a pivoted arm carrying a weight, 1, at its upper end and having a pin, '5, adapted to play in a slot, .2, in arm F, supporting the circuit-changing beam R.
In Figs. 5 and 0 I have shown a modified form of the compound bar, the parts H and L being made in this instance of polished steel tubes separated by strips of paper, as before, and having an intervening copper strip.
The operation of my improved meter is as follows: The current to be measured enters by binding-post B and passes out of bindingpost B, as shown by the arrows, as follows: wire 20, mercury-cup M, metal arm Y, mercury-cup M3 wire H72, upper steel bar, H, wire to to binding-post B and out. The heating action of the current causes the composite bar A to curve downward at its free end afer a definite time and to carry with it the cup G and bifurcated arm 13, thus forcing the pawl 1) forward, and with it the whe l Il and train of gear, and hence the recording mechanism. As shaft V is rotated to the left under this influence, it carries with it the tilting lever It], having weight P adiustably fixed on its free end. After a time this lever and weight are carried past the center of oscillation, and the TOO 7 weightl then comes into play in a manner well understood in circuit-changers of this nature and causes pin it to act on the tilting circuitchanging lever B and to take its reverse position, thereby immersing the metal points of arm Y in the mercury of cups M and M and withdrawing arm Y from cups M and M". This change of circuit withdraws the current from the bar H and causes it to pass through the lower bar, L, as follows: from B, by wire 10, to mercury-cup M arm Y, mercury-cup M, wire 10', bar L, wire 20 and out, as before. This heats bar L, and after a determinate time the operation is repeated, each action of the composite bar giving the wheel 10 a step forward by one of the pawls, p or 19 It will of course be understood that inasmuch as the heat generated in a conductor by a current of electricity flowing through it bears a fixed relation to the amount of such current, the alternate action of the pawls controlled by the bars H and L will be more or less rapid, dependent upon this fact.
I am aware that it is not broadly new with me to measure currents of electricity by their thermal effects, nor is it novel with me to meas ure and record currents of electricity by such agency, and I do not therefore claim, broadly, the application of such principle, my invention being directed to the apparatus described and claimed for utilizing or employing suc cessively the effects due to changes in temperature of two thermal conductors with circuitcontrolling devices for passing the circuit successivel y through said conductors and causing a record to be made.
What I claim, and desire to secure by Letters Patent of the United States, is v 1. In a meter for measuring and recording currents of electricity, the combination of two conductors adapted to expand under the influence of an electrical current, said conductors being connected electrically to an additional conductor carrying the currentto be measured, with switch mechanism and connections for throwing the current successively through said expansible conductors and recording mechanism controlled thereby, substantially as described.
2. A meter for measuring and recording elec trical currents, consisting of two conductors adapted to expand under the influence of an electrical current, and each having one end connected to switch mechanism for throwing said conductors into circuit successively, the other ends being connected to the external circuit and having mechanical connection with a recording-meter, substantially as described.
3. A meter for measuring electrical currents, consisting of a compound thermal bar having two conducting parts, said bar being rigidly fixed at one end and having mechanical connections at its free end with a recording-meter, the conducting portions of said bar being connected electrically with the exteriorcircuit, and switch mechanism for throwing said parts successively into circuit, substantially as described.
4. In a meter for measuring electrical currents, the combination of a compound conductor having two conducting parts insulated from each other and adapted to expandunder theinfluence of an electrical current, said parts being each electrically connected at one end to a switch for changing the circuit from one to the other, with a step-by-st-ep apparatus mechanically connected to the free end of said compound thermal conductor and a recorder controlled by said step-by-step mechanism, substantially as described.
FRANK O. XVAGNER.
GEO. B. VANCE, A. T. STEVENSON.