' (No Model.)

B. WESTON.

GALVANOMBTER. v No. 392,478 Patented Nov. 6, 1888; F5 1, g

Ill

WITNESS maul M N MUM 0R, WW5 7 In a/114% ATTORIVEY hereinafter described and claimed.

UNITED STATES PATENT G EIcE.

EDW'ARD \VESTON, OF NEWARK, NEXV J EItSEY.

GALVANOMETER.

SPECIFICATION forming part of Letters Patent No. 392,478. dated November 6, 1888.

Application filed August 17, 1888. Serial No. 282,990.

To alZ whom it may concern.-

Be it known that I, EDWARD WVEs'roN, of Newark, Essex county, New Jersey, have invented a new and useful Improvement in Galvanometers, of which the following is a specification.

My invention relates to electrical measuring apparatus, and more particularly to galvanometers wherein are contained a magnet and suspending-fiber, the magnet being provided with a mirror, from which a beam of light is reflected upon a suitable scale.

My invention consists in the construction In the accompanying drawings, Figure 1 is a vertical transverse section, and Fig. 2 is a side elevation, of a portion of a galvanometer containing my invention. Figs. 3 and 4&16Sl111llar views, respectively,to Figs. 1 and 2, showing a modification of the device.

Si milarletters of reference indieatelikeparts.

A is a cylindrical shell having an aperture forming a ring-seat for the reception of the spools D and E, which carry the coils. Said shell is supported upon the pillar B, and above it is the tube (1, said shell, pillar, and tube forming parts of the standard of the instrument.

The outer flanges, a b, of the spoolsD Eare provided with shoulders which fit over the exterior rims of the spoolsD E. The inner flanges of the spools D E do not meet when the spools are in place in the shell; but there is a space or interval left between them, through which and through the tube 0 passes the suspendingfiber F of the magnet-needle G. The cores of the spools D E are tubular, as shown.

Referring more particularly to Figs. 1 and 2, II is a short section of tube threaded at one end and screwed into the innerextremity of the core of spool D. The other end of tube II is inserted in the inner extremity of the core of spool E. In the side of tube II is alongitudinal slot, I, through which passes the filament F. The tube Hforms a chamber for the reception of the needle G.

Into the outer ends, respectively, of the cores of the spools D E are inserted short tubes J, each being flared or enlarged outwardly and covered or closed with plates K, of glass or other translucent material. The tubes J may be shouldered in the correspondingly-formed core-openings, as shown in Fig. 1.

(No model.)

Passing through the outer flanges of the spools D E are set-screws L, which enter the rims of the shellA, and thus secure the spools in place in said shell.

The parts above described are assembled as follows: The needle G being suspended in the shell A,the spool D,with the tube-section H in place, is inserted in the shell (the fiber F entering the slot 1) until the shoulder on its flange a meets the rim of the she1l,when the screws L are inserted and set up. The other spool, E, is then placed in the shell, its hollow core receiving and sliding over the end of tube H, and this is secured in like manner in said shell by screws L. In the modification of the de' vice shown in Figs. 3 ands. the tubeH is made in two portions, N N, each of which is provided with aflange or collar,i i,which extends over the faces of the inner flange of the spools D E. A radial slot, j, is formed in each collar i i. \Vhen the spools D E are placed in the shell A,the collars or flanges i 2" meet to form a spacing-disk, which comes between the faces of the spool-flanges, and the slots j coincide to form a channel through which the filament F passes.

At M are binding-screws, to which the coilterminals are secured. A mirror attached to the needle G may be observed through the glass plates or covers K, or a beam of light from said mirror maybe reflected through said plates upon a scale in the usual way.

I elaim- 1. In an electrical measuriug-instrument, a standard having a ring-seat,two spools carrying coils and received in said seat, so that a space or interval is left between the inner faces of said spools, and a magnet suspended in said interval between the centers of said spools, substantially as described.

2. In an electrical measuring-instrument, a standard having a ring-seat,two spools carrying coils adapted to enter said seat and hav' ing tubular cores, and a short tube entering the inner ends of said cores when said spools are in place in said seat, substantially as described.

3. In an electrical measuring-instruinent, a standard having a ring-seat, a spool carrying a coil adapted to enter said seat and having a tubular core, and a tube entering and sliding freely in said core and closed at its end by glass or other translucent material, substantially as described.

4. In an electrical measuring instrument containing amagnet-needle and a suspendingfilament therefor, a standard having a ringseat, two spools. carrying coils adapted to enter said seat and having tubular cores, and a short tube entering the ends of said cores-and having a longitudinal slot in its wall or side, the said filament extending through a space or interval. between the faces of the inner flanges of said spools and through said slot and supporting said magnet within said tube, substantially as described.

5. In an electrical measuring-instrument, the combination of the standard having the cylindrical shell A, spoolsD E, having wide outer flanges to extend over the rims of said shell and carrying coils, and screws L, securing said flanges to said rims, substantially as described. I

6. In an electrical measuring-instrument, the combination of the standard having the and having tubular cores, magnet G, and filacylindrical shell A, spoolsD E, carrying coils 5 ment F, substantially as described.

7. In an electrical measuring-instrument, a standard having a ring-seat, two spools carrying coils adapted to enter said seat, and means for securing the outer flanges of said spools directly to the exterior rims or faces of said seat, substantially as described.

8. In an electrical measuring-instrument, a standard having a ringseat, two spools carrying coils'aclapted to enter said seat, and means for securing the outer flanges of said spools directly to the exterior rims or faces of said seat, the axial length of the said spools being such that aspace or interval is formed between said spools when the same are in place in said 0 seat, substantially as described.

E DWARD WESTON.

WVitnesses:

D. H. DRIsooLL, PARK BENJAMIN.