US1048433A

US1048433A - X-ray tube.

Info

Publication number: US1048433A
Application number: US65285911A
Authority: US
Inventors: Jacob Howard Snively
Original assignee: Individual
Current assignee: Individual
Priority date: 1911-10-04
Filing date: 1911-10-04
Publication date: 1912-12-24
Anticipated expiration: 1929-12-24

Description

J. H. SNIVELY.

X-RAY TUBE.

APPLIOATION FILED 00124, 1911.

1,048,433. Patented Dec.24,1912.

UNITED s'rATEsrarENT oFrIcE.

JACOB HOWARD SNIVELY, OF SEATTLE, WASHINGTON.

X-RAY TUBE.

To all echo m. it may concern Be it known that I, JACOB I-IowARn SNIVELY, a citizen of the United States, residing at Seattle, in the county of King and State of IVashington, have invented a new and useful Improvement in X-Ray Tubes, f which the following is a specification.

My invention relates to an improved apparatus or device to overcome the difiici lty which has heretofore been experienced uring the use of the X-rays, withwhat are commonly called inverse, wild, secondary or Vagabond rays which originate more or less from all portions of the X-ray tube and radiate in all directions, and cause blurring of the image, streaks and indistinct outlines on the negative or fluoroscopic screen. I overcome these difliculties by the use of the device illustrated in the accompanying drawing, in which- Figure 1 is a side view of an ordinary form of X-ray tube fitted with my device and inclosed in the ordinary lead-glass protective shield. Fig. 2 is a side view of an ordinary form of X-ray tube fitted with a little different form of my device and not inclosed in a protective shield. Fig. 3 shows my device separate from the tube.

Similar letters refer to similar parts throughout the several views.

In the operation of an Xray tube, the current is conducted through the vacuum tube by means of the electrodes or conductors a, e, and i, d, and during the passage of the current particles of rarefied gases leave the concave surface i in the form of converging cathode rays which meet at the focus point E upolr'the face of the target or anode 6. Itis at this focus point E that the large quantity of X-rays are developed from impact of the cathode stream, and radiate in all directions, and it is a portion of these rays which it is desired to utilize and no others which are generated in minor quantities from all other portions of the tube. It is these so called abnormal wild or Vagabond rays developed to some extent in all portions of the tube which blur the image formed by the direct and evenly diverging rays radiating from the focus point E.

My invention consists of constructing Within the tube for generating X-rays, a cone shaped device with the base to the Specification of Letters Patent.

Patented Dec. 24, 1912-.

Application filed October 4, 1911. Serial No. 652,859..

most desirable portion of the circumference or wall 0 of the X-ray tube and the apical opening it near and pointing toward the focus point E of the target (2. This cone shaped body I) to be made of some material opaque to the X-rays such as lead-glass per haps capped with some metal atthe apex on account of the intense heat engendered at this point. The vacuum of the cone 6 forms a part of the general vacuum in the main tube through the opening h.

The cone 6 may be attached to the wall 0 of the X-ray tube by glass hangers, or in order to provide for contraction and expansion or for other reasons it might be desirable to have the cone 1) constructed as shown in Fig. 2, extending through the wall of the X-ray tube, or the device I) might be shaped like a hollow pyramid or otherwise, the idea, however, being to provide an opaque conical shaped directing tube, the apex of which being placed as near as practicable to and pointing toward the focus point of the cathode stream, and the hole or opening in the apex being so placed, so shaped and of a size to be most eflicient in admitting the greatest number of normal X-rays radiating directly from the focus point of the cathode stream, and at the same time excludethe greatest number of abnormal rays of all kinds from all other parts'of the X-ray tube.

I am aware that X-ray tubes, screens, shields, diaphragms, etc., in various combinations are in use, and do not claim my combination broadly: but

I claim:

1. In combination with an X-ray tube and located within said tube, a conical shaped device of lead glass capped with metal at the small apical opening it, and with the apical opening h, close to and directed toward the focus point E of the cathode stream on the face of the target 0, and with the open base of the conical shaped device fastened to the wall a, of the Roentgen tube, substantially as shown and for the purposes described.

2. In combination with an X-ray tube, a conical shaped device of material opaque to the X-rays, and with the small apical opening h,.close to and directed toward the focus point E of the cathode stream on the face of the target 2, and the opaqueconical device fastened to the Wall 0, of the Roentgen signed my name in the presence of two wittube, the base of the opaque conical device 6, nesses.

being closed with transparent glass actin 1 as a portion of the Wall 0 of the Roentgei l JALOB HOWARD SNIVELY' 5 tube, substantially as shown and for the \Vitnesses:

purposes described. ERNEST BERNARD HERALD,

In testimony whereof I have hereunto ERNEST AUGUST KLURZH.