US451520A - Electric meter - Google Patents

Description

(No Model.) 3 Sheets-Sheet 1.. E. W. RICE, Jr.

ELECTRIC METER. No. 451,520 Patented May 5, 1891.

(No Model.) 3 Sheets-Sheet 2. E. W. RICE, Jr.

ELEOTRIG METER.

No. 451,520. Patented May 5, 1891.

(gm/vented wi/f vwooeo 1 Edwin W276i Ezra Jr.

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No Model.) s Sheets-Sht 3.

E. W. RICE, Jr.

ELECTRIC METER.

No. 451,520. Patented May 5, 1891.

amwmtoz' Edwin Wz' Zlur lice Jr.

NITED STATES PATENT Fries;

ELECTRIC- METER.

SPECIFICATION forming part of Letters Patent No. 451,520, dated May 5, 1891.

Application filed March 8, 1889. Serial No. 302,542 (No model.)

To all whom it may concern.-

Be it known that I, EDWIN WILBUR RIoE, Jr., a citizen of the United States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented a certainnew and useful Electric Meter, of which the following is a specification.

My present invention relates to electric meters or instruments for measuring the amount of electric current conducted to a translating device of any character.

The meter of myinvention is applicable to circuits through which flow electric currents of any character, such as continuous, alternating, or intermittent.

The object of my invention is to provide a simple and accurate measuring apparatus which will, when introduced in the path of the electric current, indicate the quantity of current passing to the work, and at the same time one which shall be simple in construction and economical to manufacture and not liable to get out of order when placed in the hands of unskilled persons.

In carrying out my invention I employ the heating effect of an electric current to heat a pair of expansible bars or pieces which are properly mounted, so that neither shall be heated by radiation or conduction from the other and combine jVlllll the same suitable switching devices, whereby each may be heated in turn, the movement of expansion produced alternately in said bars being 6111- ployed to actuate or control in any suitable way a registry or recording device directly or indirectly. The bars may, for instance, control a registering or recording mechanism 0perated by power derived from some other source than the heat generated, such as clockwork, or may bring into action power derived from an electric current.

Each expansible bar may be made in various ways and still will fulfill the purpose of my invention. It may be made of a single piece of metal or other expansible substance acting on a lever; or each may be a compound bar consisting of two pieces having different coefficients of expansion by heat; or other substance than metal may be employed to replace it; and assuming a compound bar as used fastened together along their length, then when one end of such compound bar is fastened rigidly to a support, the other end will move back and forth and maintain a position dependent upon the relative expansion of the pieces forming the compound bar at any given temperature. Each compound bar so constructed may be heated by an electric current passing through the same or by heat from. an electric conductor adjacent to or in proximity to the same.

In order that the instrument may not be affected by changes in external temperature, which might introduce errors into the registry, I propose to combine with each expansible bar a suitable compensator bar or' piece mechanically connected thereto, but mounted separately therefrom, so as not to be heated by radiation or conduction therefrom, said compensator-bar being arranged to expand under the influence of atmospheric changes of temperature in a direction opposite to that in which the bar to which it is connected tends to move by the same changes.

Then two separate bars are employed for operating the register in accordance with my invention, each may act as the compensator for the other, they being arranged and connected to pull against one another under the influence of heat. This will not interfere with their operation in regulating or measuring the electric current, because they are heated alternately by the influence of the current, such alternate heating being brought about by suitable switch mechanism controlled or operated by them.

In carrying out this part of my invention I prefer to use two compound bars placed a short distance apart, but joined together and so arranged that the eifect of external temperature upon one bar is opposed or neutralized by its effect upon the other bar. I use by preference two expansible bars or pieces, because by heating first one and then the other the current is always being measured, insuring greater accuracy. To carry out this feature of my invention I cause the electric current to pass by suitable switches through or near first one bar and then the other, so that while one is being heated the other is losing its heat, until a determinate movement has occurred, when a change is made automatically in switching arrangements provided for the purpose, whereby the current is directed through a new path and heats that compound bar which has just previously been cooling. The action is then repeated, resulting in a toand-fro movement of the bars, which movement may be utilized by any suitable meanssuch as clock-work n1echanism-to indicate the number of oscillations, and therefore the current flowing to the work. It is well known that the heating effect of an electric current passing through a conductor varies as the square of the current; but I find that by cmploying two compound bars in the manner described above a compensation is effected, so that the oscillations within certain limits vary not as the square of the current, but proportionately to the current.

In the accompanying drawings, Figure l is a perspective view of a form of meter embodying my invention and a diagram illustrating themanner of application of the same to an electric circuit. Fig. 2 illustrates a modification in the manner of heating the expansible bars or rods by the electric current. Fig. 3 is an end view of the meter mechanism. Fig. i illustrates a modification in the manner of operating or controlling a stepby-step register from the movements of: the expansible bars or pieces.

In the form of my invention illustrated in Fig. 1 the bars or rods are heated by an electric current circulating in a conductor placed around them. Two such bars II II are indicated, each consisting of two pieces of expansible material C 0', having different rates or coefficients of expansion. The pieces 0 O aresecured together bysuitable bolts after the manner well understood in theart of making metallic thermostats or thermometers from compound metal bars. The compound bars II II are suitably secured at one end to posts I I fastened to a base-plate Their opposite or free ends are adapted to move backward and forward when, through the effects of heat upon the bars, such free ends are caused to flex or bend to one side.

\V W indicate coils of wire or other suitable forms of conductor applied to the bars or rods and forming the path of an electric current, which in passing through said conductors heats the same, thereby causing the expansible bars or rods to be heated. The bars II II are connected by a rigid piece B and the relative position of the two different portions 0 C of the bars is reversed in them, as shown, so that, taking, for instance, the case of the bar II, the tendency of the same to expand under the action of external heat will be opposed by the counter force of the of external temperature, affecting them both simultaneously.

The heating-conductors W \V act externally, being for this purpose introduced alternately into the electric circuit by means of a proper switch actuated or controlled by the movements of the bars themselves. A form of switch suitable for this purpose consists of a rocking lever 0, having a depending fork, as indicated, engaged by a pin 1), projeeting from cross-bar 13 The rockinglever carries contacts on n, which together are connected to one pole of a circuit, as indicated, and are adapted to dip alternately into mercury-cups M M. The latter connect, re spectively, with the coils W W, and the opposite terminals of the coils connect by wires (1, b with the opposite pole of the circuit.

The operation of the devices as far as described is as follows: In the position of the parts shown the circuit is closed by way of wire a, through conductor \V, switch M n, and out. Current passing through the coil W heats the same, which heat, being communicated to the compound bar II, causes it to expand or flex, and this flexure or expansion being communicated by the devices described or by any other suitable devices moves the lever O in a direction to finally rupture the connection at l\[' for the wire \V', and at the same time or immediately thereafter to establish a connection through the portion of the switch M, so that the current may now How by wire Z) through the conductor \V. The heat developed in the latter conductor now causes the bar II to flex and to reverse the movement of the parts, such movement eontinuing until the position of the switch is reversed and the current shifted to the other heating-conductor \V.

The devices described maybe connected in electric circuits of any kind carrying current which is the whole or a part of the current flowing to the translating devices, the consumption of current in which is to be measured, or may be connected into any other circuit in which current flows or is made to flow in accordance with the variations of consumption of current.

In the diagram Fig. 1 the simplest way of applying the device to measuring electric currents is indicated. Electric conductors or mains m n connect, respectively, to wires a e, the latter of which conveys current to a number of translating devices, such as electric lamps, (indicated at L L,) to the wire 6,

from which latter the current divides by wire a or 1), according to the condition of the electric switch, While a connects to the switch-1e ver 0, or to the contact governed thereby. The obvious effect is that the current circulating from one main m to the other main n iiicludes both the translating devices and the electric meter, and will flow in amount proportional to the amount consumed in the translating devices.

' cording device.

A tally or record of the number of movements of the expansible bars or rods may be kept by means of any registering mechanismsuch, for instance, as a train of wheels, indicated at D-a movement of which may be produced at each alternate movement of the bars through the action of an impellingpawl or other device carried by an arm a, which is connected to the rocking switch-lever 0.

Instead of depending upon the powerof the bars when expanded to operate the lever, the movement of such bars may bring into action another force to operate the registering or re- One way of doing this would be to employ an clectro-magnet operated by an electric current, the flow of which should correspond in its intervals or amount to the movements of the bars.

As indicated in Fig. 4, the current for operating the magnet might be that which circulates through the heating-coils IV IV. In this figure E indicates such an electro-magnet, which magnet operates upon the pawl which actuates the register D. In this instance the circuit through the meter is supposed to be interrupted for an instant as the switch-lever 0 changes its position, such interruption occurring in the interval between the rupture of circuit at one contact and the making of the circuit at the other contact. By this means at each movement of the switch the electro-magnet will lose its power and will then be excited again, each reverse movement, when the magnet loses its power, moving the first wheel of the register D one step.

In Fig.4 Ihave shown the meter as excited by the current developed by induction from the main or prime current,which flows through the translating devices. For this purpose the wires 6 e are simply connected to the secondary S of an induction-coil, the primary of which P is in the circuit with the translating devices. The currents in the circuit of the translating devices are in this instance supposed to be alternating currents. The electro-m agnet E may be of any desired form, or of a form especially adapted to respond to alternating currents. If the electric switch be so arranged as to not interrupt the circuit at the time it changes to shift the current from one heater to the other, an operation of the electro-magnet might be obtained by including it, as indicated by dotted lines, in one of the branches including the heater, so that such magnet will operate at every other oscillation of the switch or the expansible bars or conductors.

I do not limit myself to any particular construction of switch mechanism, nor to any particular means for bringing such switch into operation, and there are many devices heretofore employed which will readily suggest themselves to electricians as suitable for throwing the currents successively through the portions of the circuit which are to be heated by current, and to thereby cause an expansion of the bars or rods. It is also obvious that the switch mechanism might be controlled or actuated by other special devices, instead of by intermediate mechanical connections between the expansible bars and said switch.

I have shown in Fig. 2 another way in which the electric current might be made to heat the expansible bars or rods. In this instance the current is earried directly through such rods or bars, and the resistance of the material of which the rods or bars are composed causes the development of heat and the consequent expansion of such parts.

\Vhat I claim as my invention is- 1. In an electric meter, the combination, with two expansible rods, bars, or pieces separated, as described, so that neither shall be heated by conduction or radiation from the other, of two circuits or branches of circuits formed in the path of heating-currents for developing a heat to expand the same, and switch mechanism and connections for throwing the currents successively through such circuits, as and for the purpose described.

2. An electric meter having a controlling or actuating mechanism consisting of an expansible rod or bar heated when expanded by the in fiuence of an electric current and a compensating rod or bar attached to the same, but separately mounted or supported, so as not to be heated by conduction or radiation therefrom and adapted to-act in opposition to the first when both are heated at the same time.

3. The combination, with two separated expansible rods or bars, each composed of two pieces of metal having different rates or coefficients of expansion, of two electric circuits forming the path of currents in which heat is developed for causing an expansion of said bars alternately, and an electric switch mechanically connected with the said bars for throwing the current successively or alternately through said circuits, as and for the purpose described.

4. The combination, with two compound bars or rods mechanically connected and arranged to expand or bend in opposite directions under the influence of heat, of two electric coils or conductors surrounding such bars and placed in independent circuits or branches, and switch mechanism and connections for throwing the said conductors alternately into circuit with a source of cun rents, as and for the purpose described.

Signed at Lynn,in the county of Essex and State of Massachusetts, this 4th day of March,

A. D. 1889. I

EDWIN \VILBUR RICE, JR. 'Witnesses:

WM. J. I-IALL,

J. W. GIBBoNEv.

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