US2402664A - Space discharge device - Google Patents

Description

Patented June 25, 1946 SPACE DISCHARGE DEVICE Hyman Olken, Washington, D. 0.

Original application May 19, 1943, Serial No. 487,563. Divided and this application March 15, 1945, Serial No. 582,961

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 3'10 0. G. 757) 2 Claims.

This invention relates to structure of electron discharge devices and is a divisional application of my copending application, Serial No. 487,563, filed May 19, 1943, and issued May 29, 1945, as Patent No. 2,376,882.

The principal object of this invention is to provide a novel and improved structural arrangement for an electron discharge device having a novel divided anode component and in which electron flow from the cathode to each of the anode portions is varied simultaneously by means of a charged, movable element positioned exteriorly of the envelope for the device. Electron flow in one of the anode-cathode circuits is thus increased simultaneously with a decrease in electron flow in the other circuit.

The electron discharge device constituting the subject matter of this invention can be used for various applications in which a change in current in response to variation in a condition is desired. The particular application illustrated is for motor control in which it is desired to control the direction of the rotation of the motor in accordance with a change in a condition such as a change in the position of a sensitive instrument pointer. However, other applications of the invention will be apparent to those skilled in the art, and the claims are to be so construed.

Referring now to the drawing, the single figure of which illustrates a preferred embodiment of the invention, there is shown at l an envelope which has an arcuately shaped portion Illa at the top. Within the envelope and near the bottom is a cathode i I. At the top end of the envelope near the arcuately shaped portion are a pair of screen electrodes 62a and I2!) accelerating electron flow in the device. These screens should have substantially the same arcuate contour as the envelope portion Ida. Suitable potential for these electrodes is obtained from any convenient source, such as battery it. The negative terminal of this battery is connected to the cathode i I and the positive terminal is connected to both of the accelerating electrodes 82a and Nb.

Between the electrodes I21: and i212 and the interior wall of the arcuately shaped envelope portion lilo are two more screen electrodes Ma and Mb.- The wires constituting the screen electrodes i2a and Ma are aligned with respect to cathode iiand the wires of screen electrodes ifib and Nb are similarly aligned.

Screen electrodes Ida and Nb may be termed the anode elements of the discharge device. Electrode 05a is connected via conductor iii to one field winding it of a motor I? and through the 2 motor armature"! to an intermediate point l3a of the battery i3. The other electrode 14b is connected via conductor l9 to another field winding 20 of motor i1 and thence also through'motorarmature l8 to the battery point l3a.

Positioned outside of the envelope adjacent the arcuate portion "la is a plate 2| having the same contour as envelope portion Illa. This plate is supported by an arm 22 the lower end of which is mounted on a shaft 23. The latter may comprise the shaft which carries thepointer element 24 of any instrument. Plate 2! is charged to a negative potential with respect to the cathode element II by means of abattery 25 connected thereto by conductor 26.

By adjusting the voltage on the screen electrodes Ho and i2b, the streams of electrons coming through the interstices in these screens can be focussed to be in a straight or even in a divergent beam as they pass through the interstices in electrode screens a and Mb. The relative spacings and voltages on screens l2a, I2b' and Ida, Mb are furthermoreso chosen that the accelerated electrons go through the interstices in screens Ila and Nb but only slightly beyond and then tum back. The streaming electrons being slowed up near screens Ma and I 4b, a substantial portion of them will be absorbed by screens Ho and Hi), respectively.

The operation of the device should now be apparent. With the negatively charged plate 2i in a center position, the position shown in the drawing. electron flow from cathode l I will be divided into two streams of equal magnitude. Under this condition, electron flow between cathode II and anode screen I la will be the same as that between cathode H and anode screen lib, with the result that the motor field windings i6 and 20 will be equally energized producing magnetic fields of equal strength. However with the field connec-/ In the event that the instrument pointer 26 and'hence shaft 23 should rotate in a clockwise direction. plate member 2| will also move clockwise and cover more of screenllb than [4a. Because of the negative charge on plate 2 i,.e1ectron flow to the parts of the screens [4a and Nb beneath plate 2| are retarded and reverse before reaching them. Hence. as plate 2t now covers I more of screen Mb than Ma, electron flow from the cathode II to screen Mb will be less than that to electrode Ila. Thus current, flow through motor field winding I6 is increased while current flow through motor field winding. 20 is simultaneously decreased. The difference in current flow through these two field windings sets up a resultant field in one direction proportional to the current difierence and thus causes the armature 18 of motor 41 to rotate in one direction.

In the event that the instrumentpointer 24 moves in a counter clockwise direction, plate member 2| moves in the same direction and covers more of screen Ha than it does screen Nb. This brings about an opposite efiect' with the current increasing in motor field winding 20 and simultaneously decreasing in motor field winding I B. Theresultant magnetic field produced by the two field windings is then in an opposite direction and the armature l8 of motor I! is caused to rotate in the other direction.

In conclusion, while I have illustrated a preferred embodiment of the invention, it will be understood that various changes in the construction and arrangement of parts may occur to and be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or thereifor.

What is claimed is:

1. An electron discharge device comprising an envelope, a cathode disposed at one end of said envelope for emitting electrons, a pair of screen anodes disposed at the other end of said envelope, an anode-cathode circuit for each of said anodes,

anodes is simultaneously decreased thereby increasing the current flow in one of said anodecathode circuits and simultaneously decreasing the current flow in the other of said anodecathode circuits.

2. An electron discharge device comprising an envelope, said envelope having an arcuate portion at one end thereof, a cathode within said envelope at the opposite end from the arcuate portion, a pair of arcuate screen anodes disposed within said envelope adjacent the said arcuate envelope portion, an anode-cathode circuit for each of said anodes, a positively charged arcuate accelerating screen electrode disposed between said cathode and each of said anodes, a negatively charged plate member disposed exteriorly of said envelope adjacent the arcuate portion, said plate member having substantially the same arcuate shape as said anodes and accelerating electrodes, and means mounting said plate member for movement in overlapping arrangement relative to said anodes so that the overlap between said plate member and one of said anodes is increased while the overlap between said plate member and the other of said anodes is simultaneously decreased, thereby increasing current flow in one of said anode-cathode circuits and simultaneously decreasing current flow in the other of said anode-cathode circuits.

HYMAN OLKEN.

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