Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS1874577 A
Publication typeGrant
Publication dateAug 30, 1932
Filing dateJul 31, 1931
Priority dateJul 31, 1931
Publication numberUS 1874577 A, US 1874577A, US-A-1874577, US1874577 A, US1874577A
InventorsMontford Morrison
Original AssigneeWestinghouse X Ray Company Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Revolving and stationary chi-ray screen
US 1874577 A
Abstract  available in
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Aug. 30, 1932. I M, MORRlSON 1,874,577

T T oNARY x RAY scRE I Filed July 31, 1931 Patented Aug. 30, 1932 UNITED STATESKPATENT OFFICE MONTFORD-MORRISON, OF MONTCLAIR, NEW JERSEY, ASSIGNOR TO WESTINGHOUSE X-RAY COMPANY, ING., A. CORPORATION OF DELAWARE REVOLVING AND STATONARY X-RAYSCREEN Application filed. July 31, 1931.V Serialr No. 554,231.

My invention relates to X-ray grids of the type commonly utiliz-ed for preventing secondary X rays from blurring or fogging a sensitized film and constitutes an improvement on thestructure shown and described in my pending application Serial No. 547,890 led June' 30, 1931.

It is well known that when a patient is exposed to X rays emanating from an X-ray tube the hard or primary rays pass through the body of the patient and register the bones and tissues upon a sensitized film which is disposed on the opposite side of the patient from the X-ray tube. The bones and tissues of the patient when struck by the primary rays in turn give off slant or secondary rays at an angle to that of the primary rays. Unless some provision is made to prevent these latter rays from striking the sensitized film it will become blurred or foggedresulting in a defective radiographic picture.

Various devices are well known to the art for preventing the passage of these secondary rays to the sensitized film which are moved during the exposure in the field of radiation between the patient and the sensitized film. However, such devices have heretofore been diiiicult and expensive to manufacture.

It is accordingly an object of my invention to provide a grid for suppressing the passage of secondary X rays which is simple in construction and economical to manufacture.

Another object of my invention is a simplified method by which a grid for suppressing secondary X rays may be constructed.

Another object of my invention is the provision of a grid which is simple invconstruction, that may be manufacturedv in the'form of a continuous belt, or which may bein the form of a flat panel movable in the field of X-radiation. y

Still further objects of vmy invention will become apparent to those skilled in the art by reference to the accompanying drawing wherein:

Fig. 1 is a perspective view of one form my invention may take with a portion of the structure broken away to better illustrate the device;

Fig. 2 is a sectionall view of an enlarged y scale of a portion of the structure shown in Fig. l;

Fig. 3 is still another form of grid which my invention may take and Fig. 4 is a sectional view of an enlarged :sBcale of the form of my invention shown in Referring now tothe drawing in detail I have shown in Fig. 1 a unitary sheet` of material5 which is composed of a material pervious to X rays such for example as aluminum. This sheet 5 is provided with corrugations 6 which may bey formed therein by stamping or pressing the sheet in-a die. A material 7 impervious to X rays, such as lead strips, are secured to the vertical sides of the corrugations or the impervious material may be painted or sprayedthereon to a sufficient thickness to give the desired result.

A frame member 8 is provided with elongated perforations 9, for a purpose to be hereinafter more fully stated, and lateral extending slots 10 are also provided which are spaced apart a distance corresponding to the spacing between the corrugations of the sheet 5. c i

The pervious sheet 5 is fitted into the notches or slots 10 (see Fig. and secured to` the frame member, in any suitable manner, such as by means of rivets or spot welding 12.v In the event that 1t 1s desired to yrivet the sheet 5 to the frame member 8 perforations may be provided in the sheet 5, during the corrugating operation, and openings such as 13, may likewise be provided in the frame member during the stamping process when the perforations 9 and slots l0 are .made in the latter.

Upon completion of the aforementioned procedure the ends of the frame member 8 and sheet 5 may be secured together in any suitable manner, such as by welding, riveting or crimping to form a continuous belt. A pair of rollers or drums 14 and 15'are arranged to bev rotated by any suitable means, such as an electric motor (not shown) and are provided with sprocket gearing 16 and 17 respectively. The teeth of this gearing has a spacing equal to that ofthe spacing beter spacings.

f sc'opic tables.

tion the drums-14 and 15 vmay be made ad-y justable relative to each other. This enables `the continuous belt grid to bedisposed or sag from a horizontal plane to a degree suflcient to permit the corrugationswith their respective impervious strips to be radially disposed relative .toy the X rays emanating from the X-ray tube. 1 This sag of the belt grid may thus be regulated in accordance with the distance the Xray tube is disposed kfrom rthe grid.

YIn the form of my invention shown lin Figs. 3 and 4 the structure is somewhat analogous to that just described. The unitary sheet 5 ofpervious material is likewise provided with corrugations andthe vertical sides have secured thereto the impervious material .7 in the manner previously described. In this modification, however, the frame member 8 which supports the unitary sheet 5 is rectangular in configuration and is constructed of substantially U shaped channels into which sheet 5 is secured by` pressing or equal rigid securing means such as rivetingor welding. i e 1 y In order to'prevent distortion of the corrugations 6l when securing the sheet 5 into the frame member 8 I provided a series of blocks 18 (see Fig.. 4) having a cross `section equal to thespacing between the corrugations andy conforming to the configuration of these lat.

` These vblocks 18 may be'sepf ara-te or may be afiixed to the channel frame member rtopermit the corrugatedA 'sheet to slide into the frame before compressingv the frame or otherwise securing the sheet.

-the exterior of the frame member 8 to allow the completed grid to move across the field of exposure upon suitable tracks, such as shown at 20, during the period of exposure.

It can, therefore, be readily seen that I have provided a grid for suppressing the passage of secondary X rays which is simple in construction rand economical to manufacture. `The grid may be constructed in the form of a continuous belt which. may be rotated across the field of exposure during the entire period of kX-ray emanations from .the tube thus readily adapting the grid to stereoscopic radiography or it may be constructed in the form of a panel rendering the same adaptable to conventional radiographic and fluoro- Although I have shown and describedpsevv05 eralvspecific embodiments of `my invention .to the vertical'sides of thecorrugations ,of

A pluralityof rollers 19 are pivotally aflixed to I do. not Vdesire to be limited Ythereto as various other modifications of the same may be made without departing from the spirit and scope of the a pended claims.

What is claime is:

1. An X-ray grid for suppressing the passage of secondary X rays comprising a frame member, a unitary sheet of material pervious to X rays rovided with corrugations disosed in sald frame member, and material impervious to X rays secured tothe vertical ,sides of .the corrugations of said unitary sheet.

l 2. An X-raygrid for suppressing the passage ofsecondary X'rays comprising a frame member, la unitary sheet of material pervious to X rays'provided with rectangular corrugations disposedin saidframe member, andmaterial impervious to X rays secured said unitary sheet. v y

3. An X-ray grid for suppressing thepasy sage of vsecondary X rays comprising a frame member, a unitary corrugated; sheet of material perviousto X rays dis osed in said frame member, and sections o material im` v pervious to X rays 'secured to the corrugated i sides` of said sheet disposed in radialalign-r ment with X-radiations from an X-ray tube. 4. An X-ray grid for'suppressing the pas.- sage of' secondary X rays comprising a frame member, a continuousunitary sheet of material pervious to X raysprovided with cor- Y rugations disposed in `said frame member,l

vstrips of material impervious to X rays secured to the sides of the corrugations of said sheet radiallyfaligned with the' X rays emanating from an lX-ray tube when exposed to the latter, and means for moving said frame member across the'field of said, X ra s.

5. An X'ray grid for suppressing tie pas, sage of secondary ,Xrays comprising aY continuous unitary belt of material perviousto kX rays provided with corrugations, strips-of material impervious to X rays secured to the vertical sides of said corrugations, means for rotating said belt across the field of X-radiation from `an X-ray tube and displacing said belt from a horizontal plane to yenable, the sides of said corrugations to be radially disposed relative to the X-radiation. j

6.r An X-ray grid for suppressing the passage of secondary X rays comprising a continuous unitarybelt ofy Inaterialpervious toy X rays provided with corrugations, strips of material imperviousto X rays secured to the vertical sides of said corrugations, said belt being provided with a series of perforations, and a pairof revolvable drums provided with sprocket gearing arranged to engage the y In testimony whereof, I have hereuntosubscribed my name this 28th day of July, 1931. i MONTF ORD MORRISON.

weV

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4419585 *Feb 26, 1981Dec 6, 1983Massachusetts General HospitalVariable angle slant hole collimator
US5233193 *Dec 31, 1991Aug 3, 1993Fuji Photo Film Co., Ltd.Radiation image recording apparatus
US5602395 *Oct 2, 1995Feb 11, 1997Adac LaboratoriesGamma camera having partial septas and moving septas for positron emission tomography (PET)
Classifications
U.S. Classification378/155, 976/DIG.429, 378/154
International ClassificationG21K1/02
Cooperative ClassificationG21K1/025
European ClassificationG21K1/02B