US2120609A - X-ray control means - Google Patents

Description

J u ne 14, 1938. c. B. HORSLEY ET AL X-RAY CONTROL MEANS Filed March 11, 1937 FIG. 2

{EN VENT 0R5 CAPERTON HORSLEY BY EDWIN R. GOLDFIELD Patented June 14, 1938 UNITED STATES PATENT OFFICE Goldfield, University Heights, Ohio, assignors to Picker X-Ray Corporation Waite Manufacturing Division, Inc., Cleveland, Ohio, a corporation' of Ohio Application March 11,

2 Claims.

This invention relates to means for controlling the high tension circuit of an X-ray tube and the controlling means contemplated by the invention provides both compensation for variations in line voltage, and means for selectively operating the tube at any of the several kilovoltages which the technique of the apparatus demands.

Objects of the invention are to provide an extremely compact arrangement for the purpose, adapted for use in a portable control unit for the tube served, and more particularly to provide but a single handle by which the operator may make both sets of adjustments, in an exceedingly simple manner.

The exact nature of this invention together with further objects and advantages thereof will be apparent from the following description taken in connection with the accompanying drawing, in which Fig. 1 is a diagrammatic view showing a typical X-ray tube control circuit embodying the invention; Fig. 2 is a face view of the high tension circuit controller appearing in Fig. 1; and Fig. 3 illustrates in typical longitudinal section, a physical embodiment of the controller switch means appearing in Fig. 1.

With reference now to the drawing, X is the X-ray tube which is to be served by the alternating current line L1, L2, the tube having for its filament control, a filament transformer PI and filament control FC, and for its high tension circuit a high tension transformer HT, inverse voltage suppressor S, and exposure switch E. An input transformer IT is arranged to be effective between the line L1, L2, and the parts described, and a voltmeter V and milliammeter MA are arranged in the circuit to serve the usual purposes.

What has thus far been described will be appreciated by one familiar with the art as generally typical of the latter, and it will be apparent that the high tension circuit of the tube is controllable by control of the primary circuit of its high tension transformer HT.

The input transformer IT is conveniently an auto-transformer and a number of leads or taps are provided for its windings, all as indicated in Fig. 1 of the drawing, wherein the leads are indicated as a series from O to 135.

The line L1, L2, being nominally at 110 volts but actually its voltage varying at times down to say 105 and up to say 125 volts, we provide means effective between the line and the input transformer IT to adjust the transformer to the line. As here shown such means comprises a switch A connected on one side to the line L2 as by the connection a and having a number of points 1937, Serial No. 130,296

marked 0 to 9, the switch being shown as upon the point (I which is a dead point. The points I, 4 and I are all connected to the I25 lead to the transformer IT, the points 2, 5 and 8 are connected to the H5 transformer lead and the points 3, 6 and 9 to the I05 lead.

Supposing the leads of the transformer IT to indicate relative turn units in the transformer winding, and the L1 side of the line being connected to the transformer IT at the lead 50, it will be apparent that when the switch A is on point I, 4 or I, the line will be effective across that portion of the transformer IT between its leads I25 and 50, which is '75 turn units. Similarly, when the switch A is on point 2, 5 or 8, the line will be effective between the leads H5 and 50, or turn units, and when the switch is on point 3, 6 or 9, the line will be effective between the leads I05 and 50, or 55 turn units.

As indicated in Fig. 1, one side of the primary winding of the high tension tube transformer HT is connected to one end of the input transformer IT as by the line b in which are located the voltage suppressor S and exposed switch E. The opposite end of the high tension transformer primary winding is connected to a switch B which controls its relation to the transformer IT. The switch B is preferably, according to our invention, physically connected with the switch A to move with the latter, but electrically insulated therefrom, as indicated in Figs. 1 and 3. As to the physical relation of the parts, the switches are preferably arranged for coaxial movement as indicated in Figs. 1 and 3 so that a single handle AB may be provided for coincident control of both switches. In Fig. 3 the parts are shown as with the switch A on its point 2, the point I lying there opposite, and the switch B aligned with the switch A.

The switch B is provided with three segmental points including a point I23 so located that the switch B will be on this point when the switch A is on any of its points I, 2 or 3, a second point 456 so located that it will be on this point when the switch A is on any of the points 4, 5 or 6, and l a third point I89 so located that it will be on this point when the switch A is on any of its points I, 8 or 9. The point I23 is connected to the lead of the transformer IT, the point 456 to the I02 lead and the point I89 to the I35 or high end lead of the transformer.

It will be apparent then that when the switch B is on its point I23, the high tension transformer HT will be served by 80 turn units of the transformer IT, when the switch B is on its point 456, 102 turn units of the transformer IT will be available, and when the switch B is on its point 189, the entire transformer IT with its 135 turn units will be available. Obviously, therefore, the three points of the switch 13 selectively provide for the high tension circuit of the tube, three different operating conditions for the tube, such that the tube may operate at any of three kilovolt ratings selected by the operator in the usual manner according, for example, to the sections encountered in radiographic practice.

The face of the apparatus may be calibrated as indicated in Fig. 2, showing 10 points for the switch AB which, as here illustrated, is on its 0 point or off position. Corresponding to the points of the switch B, the face shows three ranges designated as Low, Medium and High. For each of these three ranges the corresponding three points of the A switch are indicated as IE5, H5 and I25, in approximation of the actual voltages met in the nominal 110 volt line L1, L2. The operator then, with the aid of the voltmeter V and knowing the desired kilovolts to be applied to the X-ray tube X, can easily select the proper position for the switch AB which will thus by a single setting of a single handle, give him a close approximation to ideal control of the high tension circuit of the tube under the instant circumstances. It is understood that ordinarily in operation of the apparatus as a whole, the handle AB is properly set before closure of the switch E to actually energize the tube.

What we claim is:

1. Means for controlling the high tension circuit of an X-ray tube from its supply line and comprising a transformer, primary switch means arranged to vary the relation of said line to said transformer, secondary switch means arranged to vary the relation of said transformer to said tube, an operator-operated control member, each of said switch means including a part connected to said control member for movement responsive thereto, and said switch means including contactors so arranged that for each relation established by one switch means a series of relations may be selected for the other switch means.

2. Means for controlling the high tension circuit of an X-ray tube from its supply line and comprising a transformer, primary switch means arranged to vary the relation of said line to said transformer, secondary switch means arranged to vary the relation of said transformer to said tube, said switch means including coaxially movable parts interconnected for their coincident operation as a unit, and said switch means including contactors so arranged that for each relation established by one switch means, a series of relations may be selected for the other switch means.

CAPERTON B. I-IORSLEY. EDWIN R. GOLDFIELD.

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