US1183871A - X-ray tube. - Google Patents

Description

E. GRIMES.

X-RAY TUBE.

APPLICATION FILED NOV- 19. 1913.

Patented May 23, 1916.

mmmmmmm WWW ELI GRIMES, OF DES MOINES, IOWA.

X-RAY TUBE.

Specification of Letters Patent.

Patented May 23, 1916.

Application filed November 19, 1913. Serial No. 801,778.

To all whom it may concern:

Be it known that I, ELI GRIMES, a citizen of the United States, residing at Des Moines, in the county of Polk and State of Iowa, have invented new and useful Improvements in X-Ray Tubes, of which the following is a specification.

The present invention relates to a vacuum or Crookes tube, such as are used for the generation of Roentgen or X-rays.

In working with X-ray tubes, the rays coming from one electrode are focused on a target located near the middle of the tube where they impinge the target and X-rays are then emitted through the side of the tube. As a result of this actionthe rays, as they issue from the point of fluorescence, diverge, which means that the tubes must be at certain definite distance from the object to be radiographed and in a certain definite angular position relative to the anode, in order that the radioactivity may be intense enough to give satisfactory results.

With the ordinary glasstube it is necessary to thus scatter the rays to prevent the heat of the rays from softening the glass and melting a spot at the focal point. The present invention aims to build the tube in such a way that the cathode rays will not be fo.- cused on the anode, which causes the X-rays .to issue therefrom in a diverging current, but

the X-rays will leave the tube as parallel rays, thus giving a more nearly homogenous radiation from the point of fluorescence.

The invention also aims to eliminate the over-heating and concentration of the rays at the focal point.

In general the invention mav be said to consist in building an X-ray tube wherein the cathode rays are not focused upon a target, and the X-rays travel out from the tube in parallel and as a homogeneous stream of substantially radioactivity. In carrying out my invention one or more of the electrodes is made of carbon, aluminum or some material relatively pervious to the rays so that the X-ray can pass through it and travel out in parallel lines without overheating the tube and without being scattered.

. In the accompanying drawings, Fi re 1 is a longitudinal section through an -ray tube embodying one form of my invention,

and Fi 2 is a vertical section through the same'tu e.

Reference now being had to the drawings, the numeral 1 indicates a cylinder of the de-' sired length and diameter. Secured to one end of the cylinder, in any well known manner, is a plate of nickel copper indicated by the numeral 2 which serves as the anode and the opposite end of the tube is provided with preferably a plate of thin carbon, indicated by the numeral 3, which serves as the cathode.

The tube .1 is exhausted, asis common with X-ray tubes of this character, and any suitable means, as is common within the art may be employed to retain the vacuum within the tube 1 to the proper degree of exhaustion.

The thin carbon plate 3 is transparent to the X-rays which are of highly penetrative power, thereby the rays of less penetrative power will be absorbed within the carbon plate. The rays from the cathode electrode 3 travel through the tube to the anode where they impinge upon the anode and are then reflected back through the cathode 3 as parallel rays (as indicated by the arrows in the drawing) ofv highly penetrative power. From this it will be understood that the anode 2 is opaque and impervious to the rays, and by sending the rays directly toward the cathode and not at an angle, as is common in tubes previously constructed, the volume of parallel X-rays is much greater than other X-rays which have been produced by directing the rays at an angle.

Whereas I have shown the anode and cathode at the ends of the tube, it is, of

course, to be understood that the electrodes may be formed within the tube or made an integral part thereof.

By the rays passing through the carbon electrode, there is no overheating and there is no concentration of the rays at any point and it also results that the rays travel in parallel lines for a great distance, not being scattered or lost.

Instead of the nickel copper electrode. a thin aluminum disk pervious'to X-rays may be substituted therefor and opposite to the carbon electrode, so that the X-rays may travel outwardly through the aluminum plate the same as they pass through the carbon plate or at least enough of the X- rays will go through the aluminum plate to impervious to X-rays and a flat electrode pervious to X-rays arranged parallel with the other electrode whereby parallel rays will be projected from the tube.

2. An X-ray apparatus comprising a tube having a fiat electrode pervious to the 'X-rays and arranged to transmit the QQ-rays emanating from the other electrode in [substantially parallel relation to one other and wlthout distortion.

3. An X-ray apparatus comprlsing 'a vacuum cylinder, an anode electrode comprising nickel copper, an electrode comprising a thin carbonlate spaced from the first mentioned electro e and in parallel relation whereby parallel X-rays may be projected from, the tube. a g

4. An X-ray tube, com'prisin a flat cathode pervious to X-rays and a at anode impervious to X-rays, whereby X-rays will be discharged through the cathode and emerge in a beam of parallel rays.

5. In apparatus of the class described, an X-ray tube comprising a'flat cathode transparent to X-rays, a flat anode parallel with said cathode and in close proximity thereto.

In witness whereof, I hereunto subscribemy name to this specification in the presence of two witnesses. ELI GRIMES.

Witnesses:

VERONICA STAPLETON, SARA B. COOPER.

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