US1716700A - Electroscope - Google Patents

Description

June 11, 1929. KLEEMAN 1,716,700

ELECTROSCOPE Filed July 9, 1926 InvenTor Richard D.Kleeman.

bH Hns'ATfo ne Patented June 11, 1929.

UITED STATES RICHARD D. KLEEMAN, OF SCHENEGTAIDY, NEW YORK.

- ELECTROSCOPE.

Application filed July- 9, 1826.

The present invention comprises an improved electroscope, that is, a device whereby electrical charges may be detected and measured.

Heretofore the sensitive elements of electroscopes have consisted of strips of gold leaf or similar very thin, light, conduct ng material. This possesses certain mechamcal disadvantages due to the fragility of gold leaf and its tendency to stick together and to anything with which it may come in contact. Furthermore, the sensitiveness of an electroscope of elements consisting of leaf is atllected by knocks or jars given to the apparatus, and it therefore does not lend itself well for measuring quantitatively electric charges in such operations as the measurement of the ionization in a given space under various conditions.

In accordance with my invention, T have provided an improved elcctroscope which is rugged, is transportable from one place to another, is adapted for immediate use after transportation and is constructed to permit accurate observation of a quantitative nature. These useful results are obtained in the device embodying my invention by utilizing as a sensitive element in the electroscope, a. threadlike wire or ribbon of metal as one of the electrodes. The greater mass and rigidity of the wire or ribbon per unit length than of the leaf is offset by having it. much longer than the leaf thereby providing greater leverage. The wire is usually more than ten times longer than the length of leaf usually used. Another feature of my invention is the construction therein of a canal-shaped chamber wherein the wire is suspended, and which prevents the wire getting entangled durin transportation. It will be described in detail in I connection with the accompanying drawings in which Fig. 1 is a front elevation partly in section of the preferred embodiment of my invention, Figs. 2 and 3 are front elevations partly in section of modifications of my invention; and Fig. 4 is a diagrammatic view of a modification in which the filamentary electrode is changed in shape in stead of being deflected during operation,

The apparatus shown in Fig. 1 comprises a casing 1 consisting of sheet metal or the like which is supported upon a base 2, the latter being provided with levelling screws 3, at in order to permit the apparatus being Serial No. 121,489.

supported in a desired alignment. The electrodes of the electroscope comprise a fine wire 5 and a. plate 6. The wire 5 preferably is looped-shaped or bifilar, being supported on both of its ends upon a rod 7 of conducting material. The wire may consist ofany suitable metal, for example silver. A ribbon may be used equally as well. I have used a -ibbon rolled from a silver wire 0.7 mils in diameter. The rod 7 is supported by a vertical partition 8 of the apparatus, a suitable insulating bushing 9 being provided to insulate the rod 7. Elcc trical connection made tothis rod by a wire 10 which leads to a terminal llprojecting through the wall of the apparatus and providing means for suitable connection to an external electric circuit. An electrically insulating bushing is provided about the terminal 10. The plate-shaped electrode 6 is connected to a terminal 12 also projecting through the wall of the container and being suitably insulated therefrom by a bushing 13. A partition 14 consisting of metal or insulating material, and carried by the supports 15 is provided within the apparatus to afford a canal-shaped chamber for the elec trode 5] A cover .16 shown partly broken away is provided for the apparatus. This cover may be secured by screws 17, or in any other suitable manner. The cover is provided with a microscope 18 on which preferably is marked a scale 19 as indicated whereby the amount of deflection of the filamentary electrode 5 may be observed.

If it is arranged that a difference of potential exists between the rod 7 and the 'ase 1, the wire 5 deflected from its neutral position. This deflection, which is observed through the window 18, is either increased or descreascd, as the case may be by an electric charge given to the terminal 12, and is a measure of the amount of charge imparted.

One of the uses of this apparatus is the measurement of the ionization produced by X-rays and radio-active radiations.

In the modification of my invention shown in Fig. 2, the filamentary electrode 21 consists of a single straight; wire which is not looped, that is, the filamentary electrode 21 is supported at one end only by a conducting support 22. The opposite electrode 6 is plate-shaped and otherwise si1nilar to the electrode 6 of Fig. 1. The otherlid parts of the apparatus correspond to the parts shown in Fig. 1-. In the modification of my invention shown in Fig. 3, both electrodes, that is, a filamentary electrode 5 and a plate-shaped electrode 6 are connected to the same terminal which in this case is represented by an external plate 25. This plate is aiiixed to the top 01. the apparatus and is connected by the conductor 26 to the rod 7 supporting the electrode 5 and this support is in turn connected by a conductor 27 to the plate-shaped electrode 6. lVhen eleclrical charges are impressed upon the plate the electrodes 5 and (3 are both charged to the same potential thereby producing deflection. This apparatus is principally useful for detecting the existence of electrical charges and for demonstrating the effect of electrical charges in an exposition of the laws of electricity for teaching purposes.

In the lllOl'llllCl'ilOl] shown in Fig. 4: the filamentary electrode 29 is supported in the shape oi a catenary from the holder 28, a canal-shaped chamber 80, 31 being provided to keep the filament in a desired position. When a charge is impressed on the electrode (3, and the filament- 29 is charged to opposite potential, it is drawn out of shape, as indicated by the dotted line, by the electrostatic attraction between the two electrodes.

lVhile I have described several specific embodiments of my invention, I wish it to be understood that various changes and arrangements may be made to my improved device without departing from the spirit oi my in *ention. For example, the orientation of the plate-shaped electrode 6 with respect to the filamentary electrode 5 may be varied,

the position shown in the drawing, being illustrative.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electroscope having a looped threadlilce electrode, and means for supporting said electrode so as to leave it free to be deflected by weak electrostatic fields.

An electroscope comprising a housing providing a canal-shaped chamber, a lilamentary electrode therein and a cooperating electrode located adjacent said filamentary electrode.

3. An electroscope comprising a housing, providing a looped, canal-shaped chamber, a looped or hifilar filamentsupported in said chamber, a cooperating electrode and means for impressing electric charges on said electrodes.

l. An eleetroscope comprising a housing,

a partition therein providing a canal bent upon itself, an electrode comprising a line wire, means for supporting said wire at opposite ends in the form of a catenary, a cooperating electrode, means for impressing electric charges upon said electrodes and means for quantitatively determining the amount of deflection of said fine Wire electrode due to said charges.

5'. An electroscope comprising a housing providing a canal-shaped chamber bent upon itself, a threadlike electrode therein, a cooperating electrode and means for indicating deflection of said electrode.

In witness whereof, I have hereunto set my hand this 6th day of July, 1926.

R1 CHARD D. KLEEMAN.

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