US3069549A - X-ray timing apparatus - Google Patents

Description

Dec. 18, 1962 J. c. THOMPSON 3,

X-RAY TIMING APPARATUS Filed April 27, 1960 3 Sheets-Sheet l v, Mommy;

Dec. 18, 1962 J. c. THOMPSON 3,069,549

X-RAY TIMING APPARATUS Filed April 27, 1960 3 Sheets-Sheet 2 Dec. 18, 1962 J. c. THOMPSON X-RAY TIMING APPARATUS 3 Sheets-Sheet 3 Filed April 27, 1960 FIG /2 l i l M M w tneys' fine 3,059,549 Patented Dec. 18, 1962 3,069,549 X-RAY TIMING APPARATUS .toseph Ciay Thompson, 1434 E. Pleasant St., Davenport, Iowa Filed Apr. 27, 1950, Set. No. 25,111 7 Claims. (11. 250-105) My invention is designed for use in connection or combination with X-ray apparatus having a vacuum or gasfilled tube such as Crookes tube or other of the many X-ray tubes in common use containing a cathode which emits cathode rays to a target reflecting plate from which Roentgen rays, commonly called X-rays, are emitted and directed to a human body or other more or less impervious object for the purpose of obtaining a shadowgraph, radiograph or.X-ray picture of an area of such body or other object upon a photographic plate held at a right angle to the main axis of the Roentgen rays at the part of the body or other object opposite the X-ray tube. Such apparatus includes a bucky upon which the photographic plate is carried, with a movable grid parallel thereto embodying strips of lead or other impervious material in alternation with corresponding strips of wood or other matter penetrable by the X-rays.

Such buckys are commonly provided with means for moving the grid laterally so as to equalize or limit the exposure of diflerent sections of the photographic plate to the X-rays.

No claim is made to X-ray tubes as such nor to the buckys nor grids separately as individual inventions.

Considerable difficulties have arisen in the past in obtaining clear and uniform pictures of the spinal column as a whole because of the variances in the size and density of various parts of successive areas of the body along the spinal column.

The objects of my invention are to provide means for use in connection with X-ray apparatus as described, to limit and control the timing of exposure of different areas of the body or spinal column to the X-rays emitted and directed by such X-ray apparatus, for timing such exposure with relation to the movement of a grid carried thereby, and to provide a shutter of thin plates of two different metals one of which can cut off the soft X rays emitted by the X-ray tube from reaching and acting on the photo plate but will permit the hard X-rays to pass to the body to be pictured and through it to the photo plate held by the bucky;

To provide means to repeat the exposure of one or more areas of the body or spinal column when the relative density and size of such area require a longer exposure than other similar areas in order to equalize and afford a more nearly uniform shadowgraph of the entire area exposed'to the X-rays;

To provide means toprevent over-exposure of smaller or less dense portions of the body relative to the necessary exposure of the larger or more dense or impervious areas;

To provide such means in simple, economical form which can be readily attached to various forms of existing X-ray apparatus in common use and be easily and economically operated by X-ray technicians;

Also to provide timing means and shutters controllable by an operator which can be combined with and will cooperate simultaneously and. effectively with X-ray ap paratus in common use for the purposes described.

I accomplish these objects by the means illustrated in the accompanying drawings, in which:

FIGURE 1 is an enlarged detail front elevation of the opaque frame 1-2 and shutter 3 mounted adjacent the outlet of the X-rays from the target of a cathode tube of X-ray apparatus, in a plane at a right angle to the path of the outgoing Roentgen rays;

FIGURE 2 is an enlarged detail rear elevation of said frame 1l2' and shutter 3 with the shutter in raised position but with phantom lines for the alternate lower positions;

FIGURE 3 is an enlarged sectional elevation of the frame and shutter on the line 3-3 of FIGURE 1;

FIGURE 4 is an enlarged sectional detail of one of the solenoids with the core and plunger in full lines;

FIGURE 5 is an enlarged front elevation of the gauge assembly used to set the trips for the switch that controls the current to the solenoids but outlines the bucky and grid in phantom lines;

FIGURE 6 is an enlarged detail of the trips and of the switch actuated thereby;

FIGURE 7 is an enlarged sectional detail on part of the line 77 of FIGURE 6',

FIGURE 8 is an enlarged sectional detail of one of the trips on the line 8-8 of FIGURE 7;

FIGURE 9 is an enlarged elevation of the gauge assembly at the left end of FIGURE 5;

, FIGURE 10 is a detail of the right end of the gauge assembly in FIGURE 5;

FIGURE 11 is an outline of the X-ray tube housing 33 with the opaque frame I mounted thereon and showing three areas of the body reached by three sets. of Roentgen rays;

FIGURE 12 is anenlarged front elevation of the bucky 34 and, in dotted lines, part of the grid 26 and the photoplate 35;

FIGURE 13 is an outline diagram of the wiring for the solenoids, bucky and switch 27 with the operators master starting switch 38;

FIGURE 14 is a reduced top or plan view of the timer housing 16.

It has now been established that X-rays are produced whenever fast-moving electrons strike a substance. In Roentgens experiment the cathode rays struck the walls of the tube so that the glass wall became the source of the X-rays. The gas-filled type of X-ray tube is a modification of the cathode-ray tube. Instead of allowing the cathode rays to strike the wall of the tube, the cup-shaped cathode C focuses them onto a metal target T, as shown in FIGURE 5-1. (Introduction to Atomic and Nuclear Physics, page 121, Henry Semart, 1959.)

My invention may be applied to the Coolidge type of tube shown on page 122 of that book or to any other of the various tubes in common use in X-ray apparatus.

It is well known that the X-rays when impelled by the target of an Y-ray tube scatter widely in diverse directions.

My apparatus is intended to be and is etfective in limiting the emitted X-rays to contact with a plurality of three or more areas of the body extending for the length of the spinal column and head of a patient.

Three areas are shown in FIGURE 11 and lie between the lines R1, R2, R3 and R4. The upper area is between lines R1 and R2 and is marked C.

The middle area B is between rays R2 and R3 and includes most of the cervical and part of the dorsal area. The lower area is between the rays R3 and R4 and is marked C.

The X-ray tube and the space in front of the target of such a tube is commonly surrounded by a cone or covering of lead or similar impervious matter. At the front or outer end of such a cone, a vertical metal housing plate preferably of lead 1 or aluminum 2, is mounted in a plane at a right angle to the axis of the target but with a central opening of suflicient size to permit free passage of outgoing X-rays from the target when not closed off by the shutter.

The shutter assembly may be attached to such a cone or to the outer end of a similar part by clips 2A-2B on the plate 2. and secured by a set screw 12. The shutter 3 may be slidably rrounted between the plates l and 2 which are held together by small bolts 14 and is preferably of lead and aluminum havinr openings in its upp P tion as shown in FIGURE 2.

It is Well recognized that different grades or types Of X-rays differ in power to penetrate a metal or a body and in their effect upon a photo plate subjected thereto.

The so-called soft rays may be stopped or greatly reduced by a thin sheet of aluminum while the so-called hard rays will pass through aluminum and require a metal such as lead to prevent their passage through it.

Accordingly I prefer to form my shutter 3 of a sheet of lead 3A preferably about 2 mm. in thickness which will resist or reduce the passage of all X-rays through it, with a sheet of aluminum 38 preferably about 2 mm. in thickness pressed into close contact with the lead. The aluminum sheet may have no openings in it but is thin enough to allow passage of the hard rays while stopping the soft rays.

The lead sheet prevents passage of 'both hard and soft rays but is provided with an open channel and additional openings in line with openings 3D as shown in FIGURE 2 through which the hard rays may travel to reach the body and photo plate to produce clear pictures free from the blurring soft rays often produce.

Stops 6A are carried by solenoids with housings 44A and extend into openings in the shutter plate 3 to hold it or to check its movement.

The housings 4-4A of the solenoids are united by Welding and the housing 4A may be welded to the up per end of the plate 2.

Each solenoid is composed of a coil of insulated wire 9 wound upon a non-magnetic support 11, andhas a Cor 6 witha plunger or stop 6A. The stops are united to the cores and extend into bores or openings in the shutter until withdrawn by the solenoids respectively. The supports 11 may be locked in place by nuts 8.

Trips 19'--29 are mounted in or on a rod 25 in a housing 16 having an opening 22 through which a pointer 18 extends to a scale 17 which may be used to adjust the position of the trips 19-29 that actuate the switch 27 and time them to successive periods of seconds or fractions thereof.

The trips are carried by a gauge rod 25 and are operable to throw a switch that can send a current through either or both solenoids to withdraw the stops and disengage the shutter, whereby the shutter will descend by gravity until it encounters another stop.

gauge rod 25 is united to the grid 26 and moves with it when the X-ray apparatus is put in action in the usual way whereby the X-rays are emitted and the grid moves along the photo plate and across the field reached by the X-rays passing through the body to be pictured.

The grid may be moved laterally by any customary means or by a solenoid 16 with feed wire 42 or any other rreans carried by the frame of the X-ray apparatus.

The stationary housing 16 for the gauge may be attached to the frame that carries the grid by a magnet 23 or other suitable means and the rod 25 that carries the trips will be attached to and movable with the grid and made movable to equalize the shadowgraphs on the photo plates.

In the use of my invention, the screen and shutter with the solenoids thereon are mounted close to the outlet of the X-ray tube at the axis of the X-rays from the target of the X-ray tube and at a right angle to the axis of the rays. The shutter is manually adjusted and raised to the highest point of its travel, leaving its lower one-half in position to cut off rays or allow them to pass for full length of a spinal column.

It is obvious that the length of exposure to the X-rays must be proportionate to the size and density of each segment or area of the body. The neck of a patient is much smaller than the head. The lower abdominal area ,4 may be larger or smaller and more or less dense than the thorax.

In using my apparatus, the first exposure is intended to be of the full length of the spinal column, as indicated by A in FIGURE 11. Then the shutter is lowered to cut off the rays from the neck at C, but continued open as to the thorax and sacral and coccygeal areas B and C.

The dorsal area B may then be cut off and exposure continued as to the lumbar or sacral area C and to make sure that the head is properly shown an additional opening 53 is made in the lead shutter plate through which X-rays may pass to the area C. atthe same time as to the sacral area C.

A plurality of interchangeable slides is provided with openings of different dimensions and spacing therein whereby exposures of any two selected parts may be longer or shorter in time and may cover wider, narrower, shorter or longer areas as appears-necessary to the experienced operator.

In taking X-ray pictures, it is common practice to warm up or heat the glass X-ray tube by a switch controlling a separate current, and after the glass is warmed, another line may be plugged in to feed electric current to the anode and cathode to start emission of, the cathode rays and of the Roentgen rays and start the grid.

In using my invention, the X-ray tube is first warmed up by the master switch 38. The current is then turned on. and flows simultaneously to the anode and cathode poles, and to av solenoid that controls the grid 26 and with it the rod 25 that carries the trips 1929 which have been adjusted, to actuate, the stops to release the shutter at the desired intervals, preferably about one second each and also flows to the automatic switch 27.

When the main electric current is turned on, the grid begins to. move laterally, the Roentgen rays travel from theX-ray tube to the body of the patient and through it to the grid and through the grid to the photo plate. For the first period of exposure of 1 to 2 seconds, the X-rays reach the entire area from the top of the head to the lower end of the coccyx, including in A all three of the areas C, B and C.

Obviously the head area is larger and more dense than the neck, likewise the abdominal area C may be thicker and more dense in a fleshy person than the neck area.

The clearness of the impressions on the photo plate depends on having an exposure of a given area of proper length. If the exposure is too short, the impression on the plate will be indistinct. If the exposure is too long, the impression will be dark and cloudy.

In order to insure sunicient exposure to obtain clear impressions of the head area C and of the lower spinal area of an obese person, one of my shutters is so arranged that after the shutter has reached the limit of its downward travel, openings therein will permit the X-rays to travel simultaneously to the head in area C and to the bottom area C until the current is cut olf from the X-ray apparatus.

Thus clear impressions may appear on the photo plate which might otherwise be faint and indistinct and the entire length of the spinal column may appear on the photo plate with substantially uniform clarity and distinctness.

The grid is arranged to be movable laterally of a stationary photo plate secured behind the grid.

The movement of the grid may be and is often produced by a coil spring and controlled by a hydromatic cylinder having an adjustable port to control the outlet therefrom so as to time such movement.

Various modifications may be made in the material and in the size and shape of various parts of my apparatus without departing from the spirit of my invention as shown by the claims and I do not limit my claims to the precise forms shown in the drawings.

I claim:

1. For use in connection with an X-ray tube and a laterally movable grid in taking shadowgraphs or X-ray pictures of all or part of the head and the areas of the body along the spinal column, an impervious screen plate mounted between the outlet of the X-ray tube and a patient being pictured, interposed in the path of the X-rays with an opening in the screen plate sufiicient to permit the X-rays to pass to the head and to the entire area along the spinal column of a person within the range of the X-rays, a vertically movable shutter to open or close said opening in whole or in part slidably mounted on the screen plate and in line with said opening, a gauge rod carried by the grid with a plurality of trips adjustably secured thereon, a switch mounted in positicn to be actuated successively by movement of the trips on the gauge rod at predetermined intervals, and to actuate a plurality of stops carried in positions to detain the shutter at any one of a plurality of points.

2. For use in connection with an X-ray tube and a laterally movable grid in taking spinographs or X-ray pictures of all or part of the head and the areas of the body occupied by the spinal column, a metal screen plate mounted between the outlet of the X-ray tube and a patient being pictured interposed in the path of the X-rays with an opening in the screen plate sufiicient to permit the X-rays to pass to the head and the entire area of the spinal column of a person within the range of the X-rays, a Vertically movable shutter to open or close said opening in whole or in part slidably mounted in the screen plate in line with said opening, .a gauge rod carried by the grid with a plurality of trips adjustably secured thereon, a switch mounted in position to be actuated successively by movement of the trips on the gauge rod at predetermined intervals, a plurality of stops carried by solenoids and spring-held in positions to detain the shutter at any one of a plurality of points, and a plurality of solenoids having their cores operatively connected to the stops respectively and their coils wired to a source of electric current adapted to pass to or be cut oil from the solenoids by the switch and the trips respectively and to retain each stop in closed position or to open them successively to allow descent of the shutter by gravity to the next succeeding stop whereby the rays to a portion of the spinal column areas may be cut off.

3. The combination with an X-ray machine for producing radiographs of human beings, having an X-ray tube and a movable grid, of a transverse screen plate of aluminum mounted adjacent the outlet of the X-ray tube in the path of the Roentgen rays passing therefrom, with an opening in the screen plate sufficient to permit the X-rays to pass to the head and the entire area of the spinal column of a person in adjusted position, a vertically movable shutter to open or close said opening in whole or in part slidably mounted in the screen plate in line with said opening, a gauge rod carried by the grid with a plurality of trips adjustably secured thereon, a switch mounted in position to be actuated successively by movement of the trips on the gauge rod at predetermined intervals to release a plurality of stops carried by solenoids in position to detain the shutter slide at any one of a plurality of points.

4. The combination as described in claim 3, and a plurality of solenoids having their cores operatively connected to the stops respectively and their coils Wired to a source of electric current adapted to pass to or be cut oif from the solenoids by the switch and the trips respectively and to retain each stop in closed position or to open them successively to allow descent of the shutter by gravity to the next succeeding stop whereby the rays either to a portion or from all of the spinal column may be cut off.

5. In an X-ray machine for use in making shadowgraphs, a grid housing carrying a movable grid shutter, a stationary gauge housing, a gauge scale mounted on the gauge housing, a rod slidably secured in the gauge housing with one end united to and movable with the grid, a solenoid carried by the grid, a switch mounted in the gauge housing adapted to turn on or off an electric current to or from the solenoid, a plug united to the core or" the solenoid seatable in the movable grid, a plurality of adjustable trips mounted on the rod each having an arm or lug in position to engage and actuate the switch whereby the plug may be withdrawn from its seat and the shutter be allowed to open.

6. The combination with X-ray tube apparatus for making shadowgraphs of a human body, of a metal screen plate mounted between the outlet of the X-ray tube and a patient interposed in the path of the X-rays with an opening in the screen plate sufiicient to permit the X-rays to pass to the head and the entire area of the spinal column of a person within the range of the X-rays, a vertically movable shutter adapted to open or close said opening in whole or in part slidably mounted in the screen plate in line with said opening, a gauge rod carried by the grid with a plurality of trips adjustably secured thereon, a switch mounted in position to be actuated successively by movement of the trips on the gauge rod at adjusted predetermined intervals, a plurality of stops carried by solenoids and spring-held in positions to detain the shutter at any one of a plurality of positions, and a plurality of solenoids having their cores operatively connected to the stops respectively and their coils wired to a source of electric current adapted to pass to or be cut off from the solenoids by the switch and the trips respectively.

7. The combination as described in claim 6, and means whereby a second short exposure of the head may be made while the exposure of the neck or abdomen is cut off by the shutter.

References Cited in the tile of this patent UNITED STATES PATENTS 1,117,266 Snook et a1 Nov. 17, 1914 1,767,756 Hall June 24, 1930 2,139,098 Raney Dec. 6, 1938 2,139,966 Loebell Dec. 13, 1938 2,214,621 Leishman Sept. 10, 1940 2,216,326 Smith Oct. 1, 1940 2,257,050 Goldfield Sept. 23, 1941 2,499,322 Mather et al. Feb. 28, 1950 2,506,342 Burke May 2, 1950 2,925,496 Zoubek Feb. 16, 1960 FOREIGN PATENTS 1,059,616 Germany June 18, 1959 1,079,448 Germany Apr. 7, 1960

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