US3060316A

US3060316A - X-ray cone

Info

Publication number: US3060316A
Application number: US708027A
Authority: US
Inventors: Leonard F Peyser
Original assignee: HOWDON VIDEX PRODUCTS CORP
Current assignee: HOWDON VIDEX PRODUCTS CORP
Priority date: 1958-01-09
Filing date: 1958-01-09
Publication date: 1962-10-23
Anticipated expiration: 1979-10-23

Description

1952 L. F. PEYSER 3,060,316

x-RAY com: Filed Jan. 9, 1958 2 Sheets-Sheet 1 F 1G. I.

as\ L INVENTOR LEONARD F. PEYSER Oct. 23, 1962 L. F. PEYSER 3,060,316

X-RAY CONE Filed Jan. 9, 1958 FIG. 3.

2 Sheets-Sheet 2 INVENTOR LEONARD F. PEYSER if V7455? plate.

Filed Jan. 9, 1958, Ser. No. 708,027 Claims. (Cl. 250-405) This invention relates to improvements in X-ray cones. More particularly, the invention is concerned with cones of the type in which adjustable apertures together with a focusing or centering light are provided. A cone of this type is disclosed in my prior application, Serial No. 561,- 400, filed January 26, 1956, for X-Ray Cone, now Patent No. 2,881,329, and the present invention is an improvement thereon, concerned primarily with the production of a compact, inexpensive cone and with an improved and simplified light centering mechanism.

In the drawing:

FIG. 1 is a side elevation of a cone embodying the invention in a preferred form;

FIG. 2 is a bottom elevational view of the device of FIG. 1;

FIG. 3 is an axial section, taken on the line 3--3 of FIG. 4; and

. FIG. 4 is a horizontal section, taken on the line 4-4 of FIG. 3.

The cone as shown in FIG. 1 comprises a shell or casing structure 1 which contains and supports the operating 'mechanism. This element is conveniently spun or otherwise formed as a single piece of sheet metal, and is generally cylindrical, being reduced in diameter at its top, as indicated at 2 and fastened to a rectangular plate 3 which serves as a flange for attaching the unit to the X-ray machine in a known manner. The diaphragm structure is supported principally by an annular plate 5 fixed to the shell 1 by means of posts 6. A rectangular diaphragm structure is carried above the plate 5 and comprises (FIGS. 3 and 4) a pair of gib blocks 7 which are slotted as indicated at 8 and 9 to provide guideways for a pair of generally L-shaped diaphragm plates 10, 11. The diaphragm defining edges 12, 13 of these plates are located with reference to the central axis A of the unit so as to form a rectangular aperture having a proportion of about 4-5 between long side and short side. In the unit illustrated, and in which the shell 1 has a diameter of a little less than five inches, the diaphragm opening (long dimension) may be varied from about an inch to about two and one-half inches. The operating mechanism for the rectangular diaphragm just mentioned is of a very simple character and comprises spring means for urging the elements 10, 11 toward open position and positive camming means for urging them toward closed position. A spring 15 is secured to each element 10, 11 by a screw 16, passes in a generally radial direction therefrom around a pulley 17 rotatably mounted on the plate 5 and then in a generally tangential direction to a screw 18 attached to this In this manner, a relatively long spring is provided within the rather confined space available, and a smooth, steady spring action is obtained. Mounted on the lower side of each plate 10, 11 is an angular cam member or shoe 19, the rounded corner 20 of which engages the operating mechanism about to be described.

This operating mechanism takes the form of an iris diaphragm generally similar to that described in my above indicated application, and is mounted on the lower side of the plate 5. The mechanism comprises a number of, shown as ten, diaphragm leaves 21, each of which is pivoted at its upper and outer end to the lower side of the plate 5 on a pivot pin 22 and carries at its lower and inner end a cam roller 23 having flanges 24 and engaging in a cam slot 25 formed in the rotatable actuating ring 26.

States atom This ring floats within the shell -1, being supported by cam rollers 23, whose upper and lower flanges 24 overlap the edges of the slots 25, and is provided with an operating handle 27 fixed to the member 26 by a bracket 28 and extending through a slot 30 in the wall of the casing. Attached to the handle and movable therewith is an index pointer 31 cooperating with a scale 32 attached to the shell 1 and marked with suitable indicia for indicating area and film size exposed at various distances from the cone or X-ray machine. As will be apparent, turning ring 26 by means of handle 27 causes the walls of the slots 25 to exert a camrning action on rollers 23, forcing the leaves 21 inwardly and outwardly, as desired. Since the cam angles 19 attached to the diaphragm plates 10, 11 engage the edges of these leaves, the adjustment of the iris diaphragm by means of handle 27 simultaneously adjusts the rectangular aperture 10, 11 and in a proportional manner. In other words, the diameter of rectangular aperture 10, 11 will equal the iris diaphragm aperture diameter plus a small amount corresponding to the distance between the corner of the rectangular aperture (FIG. 2) and the rounded engaging surface 20. In consequence, the generally circular opening of the iris diaphragm has the profile of a circle only slightly larger than a theoretical circle circumscribed about the rectangular aperture. The spacing of elements 19 from the aperture defining edges of member 10, 11 is, however, sufiicient to place these elements outside the limits of the radiation beam defined by the cone. It will be observed that in small aperture settings, the outer edges of plates 10, 11 will have moved inwardly sufiiciently so as to permit passage of the X-ray beam around their outer edges. However, the iris diaphragm leaves 21 extend, as before noted, from the circular outline within the limits of the plates 10, 11 and back almost to the wall of the casing 1, thus screening against any radiation which may pass the outer edges of the plates 10, 11. In consequence, the plates 10, 11 and the iris diaphragm, taken together, constitute at all times an effective radiation controlling diaphragm having an eifective outer diameter substantially equal to that of the casing 1 and an eflective opening as defined by the plates 10, 11.

Diaphragm plates

10, 11 and 21 are preferably made of lead, having a high opacity for X-rays, and backed or laminated on one or both sides with aluminum or stainless steel alloy or other suitable metal having the required characteristics of mechanical rigidity and wear resistance.

The light centering device of the present invention comprises a light projector unit 35 aifixed to the wall of the shell 1 as indicated and projecting a narrow beam of light along the path Pi, Pr. The unit may contain a light bulb 36 (FIG. 3) and any convenient optical system, shown in the present case as comprising a single lens 37, and may be operated from an A.C. power supply or by means of batteries. In the present case, the cone is shown as equipped with a battery case 38 connected to the light 36 by wiring 39 and controlled by switch 40.

The incident beam Pi-projected by the light unit 35 is reflected (reflected beam Pr) off a mirror 41 carried by a support plate 42. .The plate 42 is formed of low opacity material, preferably methyl-methacrylate (Plexiglas, Lucite) sheet, and comprises two plane circular segment portions 43, 44 (FIG. 3) joined by a slanted plane portion 45 set at an angle (in this case, 45) suitable for directing the reflected beam Pr downward along the central axis of the cone. The plate 42 is conveniently formed by bending a sheet of plastic of suitable thickness (about to the shape indicated and cutting to a circular contour for fitting into the shell 1. An opening 46, to take the mirror 41, is cut in the central part '45. This opening is preferably formed as a circular bore at right angles to the central part 45 of the support plate 42. Mirror 41 preferably takes the form of a disk of plastic sheet, sil-vered on one side to provide a light reflecting surface, and fitting with a press fit in the opening 46, where it is secured by a thin film of adhesive. The silver disk is preferably formed of the same material as the support plate 42 and may be cut from the same sheet, and is preferably inserted with the mirrored side on top or inwardly of the casing, so as to minimize dust accumulation on this surface. The mirror support plate 42 is carried by four support posts, each comprising a bolt 50 passing through an annular flange 51 secured to the lower end of the casing 1 as by screws 52, and also passing through a

flat surface

43 or 44 of the member 42 and being fitted with a nut 53 above this surface. The bolts 50 associated with the fiat surface 44 are surrounded by springs 54 thrusting against the flange 51 and through washers 55 against the fiat part 44 of the member 42. The bolts 50 associated with the flat part 43 are similarly provided with springs 56 and with tubular thrust members 57 in view of their greater length. A screw 50 is provided at each side of fiat surface 43 and again at each side of flat surface 44, so that by turning the screw 50 so as to vary the position of the nuts 53 therealong, it is possible to raise and lower the member 42 and to tilt it about any horizontal axis, so that the reflected beam Pr is accurately positioned along the axis of the cone.

In use, the cone will be placed on any convenient X-ray machine and provision will be made according to standard practice for the type of machine and type of work involved, for filtering out relatively soft, scattered radiation. The typical filtration provided will generally be equivalent to about .5 mm. of aluminum within the X-ray tube itself and an additional filtering equivalent to another 1 or 2 mm. of aluminum and provided by means of a filter plate or plates interposed between the cone and the tube. The Plexiglas or Lucite sheet 42 in a thickness of about will be of an opacity equivalent to only about .05 mm. of aluminum (increased by about 40% in the central part 45 due to its angular setting). The variation in opacity to X-rays in the member 42 will, accordingly, amount to only about the equivalent of .02 mm. of aluminum, which being less than 1 or 2% of the total filtration provided in any event, is negligible and will not affect the picture obtained under any normal operating conditions.

What is claimed is:

1. An X-ray cone comprising a pair of generally L-shaped aperture plates defining a rectangular aperture, means mounting the said plates for sliding movement toward and away from each other to vary the size of the aperture defined thereby, spring means yieldably urging the said aperture plates apart, an adjustable iris diaphragm adjacent the said aperture plates defining a round aperture surrounding the rectangular aperture outside the radiation beam path defined thereby, and means carried by the said aperture plates and extending into the aperture formed by the iris diaphragm to engage against the edge thereof, whereby contraction of the iris diaphragm forces the said aperture defining plates together against the action of the said spring for regulating the size of the rectangular aperture.

2. An X-ray cone comprising a pair of generally L-shaped aperture plates defining a rectangular aperture, an annular support plate below the said aperture plates, gib blocks carried by the support plate mounting the said aperture plates for sliding movement toward and away from each other to vary the size of the aperture defined thereby, spring means yieldably urging the said aperture plates apart, an adjustable iris diaphragm located immediately below the said support plate and defining a round aperture surrounding the rectangular aperture outside the radiation beam path defined thereby, the said iris diaphragm comprising a plurality of leaves pivoted at their outer and upper ends to the said support plate, a slotted rotatable ring for adjusting the iris diaphragm and rollers carried by the inner and lower ends of the said leaves engaging in slots of the said ring and supporting the said ring, and means carried by the said aperture plates and extending into the aperture formed by the iris diaphragm to engage against the edge thereof, whereby contraction of the iris diaphragm forces the said aperture defining plates together against the action of the said spring for regulating the size of the rectangular aperture.

3. An X-ra-y cone comprising a pair of generally L- shaped aperture plates defining a rectangular aperture, means mounting the said plates for sliding movement toward and away from each other to vary the size of the aperture defined thereby, spring means yieldably urging the said aperture plates apart, an adjustable iris diaphragm adjacent the said aperture plate defining a round aperture surrounding the rectangular aperture outside the radiation beam path defined thereby, and cam means carried by the said aperture plates and extending into the aperture formed by the iris diaphragm to engage against the edge thereof, the said cam means engaged slidably against leaves of the iris diaphragm to permit vertical and circumferential movement of the said leaves, whereby contraction of the iris diaphragm forces the said aperture defining plates together against the action of the said spring for regulating the size of the rectangular aperture.

4. An X-ray cone according to claim 3, in which the said cam means comprise a pair of angular shoes fixed to the aperture defining plates outside the path of a beam defining thereby.

5. An X-ray cone comprising a pair of generally L- shaped aperture plates defining a rectangular aperture, an annular support plate, means mounting the said plates on the support plate for sliding movement toward and away from each other to vary the size of the aperture defined thereby, spring means yieldably urging the said aperture plates apart, and comprising for each aperture plate a spring attached to the aperture plate at one end and to the support plate at the other and a rotatable spring guide pulley carried by the support plate, the spring passing in a generally radial direction from the aperture plate around the guide pulley and then in a generally circumferential direction, an adjustable iris diaphragm immediately adjacent the said support plate defining a round aperture surrounding the rectangular aperture outside the radiation beam path defined thereby, and means carried by the said aperture plates and extending into the aperture formed by the iris diaphragm to engage against the edge thereof, whereby contraction of the iris diaphragm forces the said aperture defining plates together against the action of the said spring for regulating the size of the rectangular aperature.

References Cited in the file of this patent UNITED STATES PATENTS 2,204,465 Baier June 11, 1940 2,474,421 Hollstein June 28, 1949 2,474,422 Hollstein June 28, 1949 2,542,196 Haupt Feb. 20, 1951 2,614,224 Wright Oct. 14, 1952 2,667,588 Oswald Jan. 26, 1954 2,675,486 Green et al Apr. 13, 1954 2,844,736 Johns et a1 July 22, 1958 2,881,329 Peyser Apr. 7, 1959 2,894,144 Barrett July 7, 1959