Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an adapter for a portable x-ray apparatus and more particularly to a shielded and fully adjustable x-ray adapter for completely enclosing a portion of installed objects to be x-rayed.
2. Description of the Prior Art
X-ray inspection devices are well known in the industry; in particular where high quality control and non-destructive testing and examining of manufactured objects are concerned.
For instance, the U. S. Pat. No. 3,454,762 by Vollmer shows a typical set-up for x-ray viewing of electronic components; however, the x-ray radiation operation takes place in a separate lead-insulated room, because, as well known, the x-rays are very detrimental to the living cells and tissues of human beings.
Portable x-ray apparatus are therefore used with utmost safety precautions, and shielding devices are used to keep leaking of primary and secondary radiations to an absolute minimum. A typical example is the apparatus shown in U. S. Pat. No. 2,360,036 by Boucher, U. S. Pat. No. 2,436,279 by Wilson, and U. S. Pat. No. 3,508,059 by Vanderpool. However, it will be noted that these devices are specifically designed to emit x-rays in a certain direction and that shielding is provided parallel or about the x-rays. Furthermore, it will be noted that these devices are not preventing secondary x-ray leakage so that the use of the devices is limited to operations during times that people are not around.
The same problem arose when x-rays were made of welded hydraulic tube joints, installed in-place within the Boeing airplane 747 structure. In order to inspect a tube joint by portable x-ray apparatus, the entire aircraft and immediate surroundings were completely evacuated. Rope barriers had to be set up and surveillance was maintained to prevent workers from entering the critical area of 2 mr/hr (milli-roentgens per hour) that was measured at the barriers 25 to 50 yards from the operating x-ray tube. The 2 mr/hr is the safety limit or maximum allowed radiation per health protection safety standards for non-occupational personnel. Obviously, with this method of inspection and safety precautions, it was impossible to keep up with the production. Tube welds were being made at the rate of seven to 10 per day. To set up and x-ray each tube weld, it required an average of 25 minutes per weld joint.
The present invention solved the above problem and provided for such an absolute shielding that manufacturing personnel were allowed to continue their work in and outside the aircraft structure while the radiographic x-ray exposures were being made.
In one month, 400 x-ray radiations were made of tube welds and less than 2 mr/hr was measured at a distance of 3 feet from the x-ray operation, and each operation lasted less than 5 minutes, which includes the set-up and exposure time of the x-ray film. Briefly, the shielded x-ray adapting device offers a minimum of radiation leakage and allows radiographic inspection of portions of objects installed in large structures by portable x-ray apparatus, without disturbing and interrupting environmental non-related activities.
SUMMARY OF THE INVENTION
The shielding apparatus is designed and built to safely use x-ray generating equipment in the field and factory areas, within the Radiation Health-Protection Requirements of less than 2 milli-Roentgens in any given hour to non-radiation personnel. The adapter is like an arm of a polyp and can reach in hard-to-reach places with its container acting as a tentacle, thus completely surrounding and enclosing a tube joint. The x-ray tube emission head is surrounded and enclosed by a collar and tube internally covered with a blanket of lead or any similar type of x-ray radiation shielding material. The tube is disposed parallel about the emitted radiographic rays and acts as a collimator. At the end of the collimator is a rotationally and pivotally mounted container. The container has a longitudinal shape and is disposed in a substantially perpendicular direction with respect to the collimator. The container has an upper part which is pivotally engaged with the collimator and a bottom part which is hingedly attached to the upper part. When both parts are closed together, their overlapping edges provide for a seal or leak-proof engagement, and in this closed condition, two apertures are caused which are oppositely located. The apertures are circular and supplement the tube periphery. The bottom part has a slit on opposite sides, and lead lined strip film material is thus fed into the closed container underneath the enclosed tube portion.
Since the meeting edges of the upper and bottom parts of the container overlap and the collimator is provided with a shielding collar overlapping the insert pivotal connected arrangement, leakage of primary radiation is impossible and leakage of secondary radiation is kept to a minimum.
It is therefore an object of the present invention to provide for a shielded adjustable adapter for portable x-ray apparatus with means of completely enclosing a portion of a longitudinally installed object to be x-rayed with a minimum of secondary radiation leakage.
It is another object of the present invention to provide for a shielded x-ray adapting device which encloses completely a tube weld to be x-rayed, and which device is completely adjustable, allowing the x-ray beam to pass through the subject at an angle that permits adequate image projection on the x-ray film so that utilization in hard-to-reach areas is feasible.
It is a further object of the present invention to provide for a portable x-ray apparatus with an adapter as mentioned, and with insert means that complement closure of cross-sectional peripheries smaller than the aperture periphery of the enclosure means.
These, and other objects, features, and advantages of the invention, and the manner in which the same are accomplished will become readily apparent from the detailed description of the device taken in conjunction with the accompanying drawings illustrating the preferred embodiment of the invention.
THE DRAWINGS
FIG. 1 is a copy of an actual photograph showing a portable x-ray apparatus and thereon mounted shielding device;
FIG. 2 is a perspective view of the shielding container in an open condition;
FIG. 3 is a sectional front view of the container;
FIG. 4 is a sectional side view of the container;
FIG. 5 is a typical configuration of an insert means which enables radiography of smaller diameter tube joints.
DESCRIPTION OF THE INVENTION
Referring now to the drawings, the perspective view in FIG. 2 illustrates most of the details of the shielding device 10 which comprises a tubular housing or collimator 12 including a pivotally connected container 14.
The upper or first end portion 16 of the collimator 12 is mounted about the x-ray tube of the portable x-ray apparatus 18. This mounting is completely leak-proof and preferably in connection with a collar or bearing construction so that rotation about the collimator 12 longitudinal axis is possible. The lower or second end portion 20 of the collimator 12 is pivotally mounted within the container 14 by pivot means 22. The pivotally mounted arrangement of the container 14 with the collimator 12 enables variation of the position of the container 14 with respect to the collimator axis. For instance, in FIG. 3 the dashed outline shows the varied angle of the collimator to the object, which is a tube joint 24 in the present illustrated application, to be x-radiographed. Thus, in reality the operator pivots the collimator 12 with respect to the container 14 that is clamped about the tube joint 24 and exposes a film at, for instance, a 15° angle from the collimator axis and thereafter one coincident with the axis. Of course, a variety of x-ray pictures at various angles can be made, all depending on the requirements.
Referring further to FIG. 2, the container 14 has an upper part 30 and a bottom part 32 which are hingedly attached by a piano-type hinge 34. The upper part is further equipped with a pair of closing bolts 36 and a micro-switch means 38 which has an accurate setting for assuring the appropriate closing torque on the bolts 36. As shown, the inner lining of the container and the collimator is made of a radiation shielding material such as lead 40, etc., and is arranged in a step-type fashion at the closing edges 42 and 44 of the upper 30 and bottom part 32, respectively, so that x-ray leakage is prevented when the container 14 is properly closed and the edges 42 and 44 are abutting with one another. The collimator portion 20 that is enclosed inside of the upper part 30 has a pair of slots 46 with an end radius which complements part of the tube joint 24 circumference.
Since the slots 46 may cause a small amount of leakage towards the opening 50 which allows the entering of the collimator 12, a pair of lead-lined flanges 52 are mounted to the portion 20 which extend almost perpendicularly from the collimator 12, as shown in FIG. 3.
The bottom part 32 is provided with a lead contoured liner 54 that partly envelopes the tube joint 24 and a pair of oppositely located slots 56 in the fore and aft side respectively for passing through of a film strip 60.
These film strips 60 contain a leaded material, and in addition the slots 56 are in a downward and inward direction, as shown in FIG. 4, so that any type of primary or secondary radiation leakage is substantially reduced.
In order that various diameters of tube joints can be x-rayed, an insert means 70 comprising a male 72 and a female member 74 that fit closely inside of each container part 30 and 32 has been designed as shown in FIG. 5; however, various other methods can be used, such as wrapping the tube with lead until the hole diameters of the container 14 is reached, or by using a one-piece insert having a "U" shape slot at each side end which fit closely about the smaller tube joint to be x-radiographed.
In order to x-ray in hard-to-reach places, the collimator may have a telescoping arrangement 80, as shown in FIG. 1, and may also be provided with various pivotal or angular bending arrangements not shown herein.
Having thus described the operation and details of the present invention, it should be understood that various modifications and alterations to the preferred illustrated embodiment may be made without departing from the spirit and scope of the invention as defined by the appended claims.