US2673627A

US2673627A - Electromagnetic lock for x-ray apparatus

Info

Publication number: US2673627A
Application number: US166016A
Authority: US
Inventors: Robert J Stava; Walter G Reininger
Original assignee: Picker X Ray Corp
Current assignee: Picker X Ray Corp
Priority date: 1950-06-03
Filing date: 1950-06-03
Publication date: 1954-03-30
Anticipated expiration: 1971-03-30

Description

March 30, 1954 R. J. sTAvA ErAi.

ELECTROMAGNETIC LOCK FOR X-RAY APPARATUS 9 Shets-Sheet l Filed June 3, 1950 WW ff S//l//l/ March 30, 1954 R. J. sTAvA ET AL 2,673,627 -ELECTROMAGNETIC LOCK FOR X-RAY APPARATUS Filed June 3, 1950 March 30, 1954 R. J. sTAvA ErAL ELECTROMAGNETIC LOCK FOR X-RAY APPARATUS 9 Sheets-Sheet 3 Filed June 5, 1950 9 Sheets-Sheet 4 .Illlllll l R. J. sTAvA ETAL LVM# IIIMIIIIIVIHH ELECTROMAGNETIC LOCK FOR X-RAY APPARATUS March 30, 1954 Filedy June 3, 1950 March 30, 1954 Filed June 3, 1950 R. J. STAVA ET Al..

ELECTROMAGNETIC LOCK FOR X-RAY APPARATUS 9 Sheets-Sheet 5 ETUI;

779 arma/5 R. J. sTAvA ET AL 2,673,627

ELECTROMAGNETIC Loox FOR x-RAY APPARATUS 9 Sheets-Sheet 6 0 m Il w A J 1 ...l| am.. a, |..|.||m:| ,f1 |..l -C v I v I 7 5 4 l M// Q /f lWH\h\.\\

March 30, 1954 Filed June 3, 1950 March 30, 1954 R. J. sTAvA ETAL ELECTROMAGNETIC LOCK FOR X-RAY APPARATUS 9 Sheets-Sheet 7 Filed June 5. 1950 F fg .50

r e Mmmm w JW 0 e f fe @W @wa .Y

March 30, 1954 R. J. sTAvA ETAL ELECTROMAGNETIC LOCK F'OR X-RAY APPARATUS 9 Sheets-Sheet 8 Filed June 5, 1950 March 30, 1954 R. J. sTAvA r-:T AL

ELECTROMAGNETIC LOCK FOR X-RAY APPARATUS 9 Sheets-Sheet 9 Filed June 3, 1950 Lf, c

Q E 53W Vde um 4, j

Flg.40

7 /0 O d L/ Patented Mar. 30, 1954 ELECTROMAGNETIC LOCK FOR X-RAY APPARATUS Robert J. Stava, University Heights, and Walter G. Reininger, Cleveland, Ohio, assignors to Picker X-Ray Corporation, Waite Manufacturing Division, Inc., Cleveland, Ohio,

tion of Ohio a corpora- Application June 3, 1950, Serial No. 166,016

20 Claims. (Cl. 188-165) This invention relates to X-ray apparatus and more particularly to a manner and means of controlling and arresting the inherent movement of relatively movable members of the apparatus.

X-ray apparatus may be employed for various diagnostic and treatment purposes, and the manner of employment involves various techniques depending upon the type of examination or treatment, such as radiography or uoroscopy. Accordingly, this type of apparatus must usualli7 be constructed so that the various operable members of the apparatus can be moved to a plurality of positions individually or in combination in accordance with the technique employed. 'Operation of an apparatus of this type which requires many relative movements also inherently requires means for arresting such movements. This is particularly true in the operation of X- ray apparatus where many of the nal settings of movable members, such as the X-ray tube or iluoroscopic screen, require accuracy and prohibition against misalignment.

Heretofore, various types of mechanical locks in the form of screw or toggle mechanisms have been utilized for this purpose in X-ray apparatus. Such mechanical locks, however, are widely separated and require periodic adjustment and alignment, thus making operation of the apparatus inconvenient and burdensome for the operator.

Accordingly, it is an object of this invention to provide a magnetic type lock for X-ray apparatus which may be conveniently located for operation and which requires a minimum of adjustment and maintenance.

Another object of this invention is to provide an electro-magnetic lock for X-ray type apparatus having a plurality of movable elements and, which lock is self-adjusting and subject to remote control.

A further object of this invention is to provide` an Y-ray type apparatus having a plurality of relatively movable members and having a magnetic type lock for arresting each of the members individually, or in combination.

Briefly, in accordance with this invention an electro-magnetic type lock is provided which embodies a magnetic core surrounded by an energizing coil adapted to be carried by a supporting member and having a flexible member adjacent one face of the core which frictionally engages another member of the apparatus upon energization of the magnet coil whereupon the magnet is attracted to the other member in ,locking relation. Various combinations of the electro-magnetic type locks are distributed in operative relation throughout the X-ray apparatus in association with the various relatively movable members and have individual or combined energizing circuits including controlling switches, whereupon certain members of the apparatus may be arrested in movement individually or together with certain other movable elements in predetermined relation.

These and other objects and advantages of the invention will be further understood from the following description when considered in connection with the accompanying drawings and as pointed out in the appended claims.

In the drawings,

Fig. 1 is a section of an electro-magnetic lock shown in relation to a cooperating track;

Fig. 2 is a view of the electro-magnetic lock taken along the lines 2-2 0f Fig. 1;

Fig. 3 is a perspective View of the electromagnetic lock showing the hexagonal form;

Fig. 4 is a perspective View of a portion of an electro-magnetic lock supporting member showing the cooperating hexagonal opening;

Fig. 5 is a view showing the rigid mounting of the electro-magnetic lock to a supporting plate;

Fig. 6 is a view showing a spring-type mounting for the electro-magnetic lock;

Fig. 7 is a side elevation of the X-ray apparatus showing in dotted lines the longitudinal track for the iiuoroscopic column and associated electro-magnetic locks;

Fig. 8 is a top view of the X-ray apparatus taken along the lines 8 8 in Fig. '7;

Fig. 9 is an end view of the X-ray apparatus taken along the lines 9 9 in Fig. '7;

Fig. 10 is a perspective view of the X-ray apparatus showing in dotted lines both the longitudinal and crosswise tracks for the fluoroscope supporting column;

Fig. 11 is a partial section of the crosswise track taken along the lines II-I I in Fig. 10;

Fig. 12 is a view of the crosswise track taken along the lines I2-l 2 in Fig. 11;

Fig. 13 is another view of the crosswise track taken along the line l3-l3 in Fig. 11;

Fig. 14 is a diagram of the electro-magnetic lock energizing circuit for individual control of the crosswise movement of the iiuoroscope column relative to the table;

Fig. 15 is a side elevation of the X-ray apparatus showing the table in vertical position and .showing in dotted lines the longitudinal track and associated counterweight,arrangement for the uorosco'pe supporting column;

Fig. 1G is a sectional view of the longitudinal track taken along the lines IS-IB in Fig.

Fig. 17 illustrates electro-magnetic lock circuit diagram for combined control of the longitudinal and crosswise movement of the fluoroscope supporting column relative to the table and including a centering means;

Fig. 1S is another embodiment of the electromagnetic lock circuit diagram including a pushbutton control for combined action;

Fig. 19 is still another embodiment of the electro-magnetic lock circuit diagram Afor combined control of the longitudinal ,and crosswise movements and including compression control of the Iiuoroscopic. unit;

Fig, 20 is a top view of the fluoroscope unit including the screen and spot film support and showing in dotted lines the `pivotal horizontal positioning of the nuoroscope unit;

Fig. 2l is a side elevation of the luoroscope supporting column and luoroscope unit showing in dotted lines the horizontal positioning lock vfor the unit;

Fig. 22 is a cut-away section taken along the lines 22-22 in. Fig. 20;

Fig. 23 is an electro-magnetic lock energizing circuit for individual control of the iluoroscope unit horizontal lock Fig. 2li is an end elevation of the X-ray apparatus showing, in dotted lines the vertical positioning of the uoroscope unit and the associated electro-magnetic lock;

Fig 25 is a top View of the uoroscope unit showing the compression and vertical position electro-magnetic locks;

Fig. 26 is a partial sectional View taken along the lines 23-23 in Fig. 27;

Fig. 27 is another partial sectional view of the vertical magnetic lock taken along the lines 24-2@ in Fig. 22;

Fig. 28 is a partial side elevation showing in dotted lines the vertical positioning electromagnetic locks for the fluoroscope unit along the supporting column;

Fig. 29 is a rear view of the top of the supporting column showing in dotted lines the vertical positioning electromagnetic locks and associated counterweight;

Fig. 30 is a partial section taken along the lines 33--30 in Fig. 29 and showing the .electromagnetic locks and carriage rollers in detail;

Fig. 3l is a side elevation of an auxiliary X-ray tube stand showing various electro-magnetic locks and a vertically movable X-ray tube carriage including a counterweight arrangement;

Fig. 32 is a view taken along the lines 32-32 in Fig. 3l, showing the tube stand, rollers, track, and associated electro-magnetic locks.;

Fig. 33 is a top view of the tube stand under carriage taken along the lines r33--33 in Fig. 32;

Fig. 34 is a rear View of .the auxiliary X-.ray tube carriage shown mounted on a cut-a-way portion of the tube stand and showing in dotted lines the carriage electro-magnetic locks and associated rollers;

Fig. 35 is a front view of the carriage Yof Fig. 3.4 showing the dial for indicating the angular position of the auxiliary vX-,ray tube relative to the stand;

Fig. 36 is a side elevation of the X-ray apparatus showing the bucky radiograph assembly in relai-tion to the X-ray tube stand and fluoroscopic unl Fig. 37 is a sectional view taken along n.the lines 31-31 in Fig. 36, showing the various positions of the nlm cassette tray relative to the bucky carriage and the associated electro-magnetic lock;

Fig. 38 is a top view of the table showing in dotted lines the various positions of the lm cassette relative to table;

Fig, 39 is an enlarged sectional view of the bucky assembly electro-magnetic lock; and

Fig. 40 is an energizing circuit diagram for individually controlling the bucky assembly electromagnetic lock.

The electro-magnetic lock of this invention is shown in detail in Figs. l to 6. The remaining figures of the drawings illustrate by way of example, various applications of such an electromagnetic lock in a particular type of tiltable X-ray apparatus.

Referring lto Fig. 1, a hexagonally shaped electromagnet I is mounted on a supporting member 5. The magnet I may be made of soft iron or other suitable low residual magnetic material and yis hexagonally shaped on the exterior, as shown in Fig. 3, to prevent rotation of the magnet relative to the supporting member 6. The magnet I has an interior concentric slot for receiving an energizing coil 2. This construction results in a magnet having an inner central core 3 surrounded by a coil, both of which are enclosed by the outer leg or perimeter 4 of the magnet I. A magnetically susceptible member 5 of iron, steel, or like material is positioned adjacent the core face of the magnet 3.

A source of electrical energy, not shown, may be connected to the 1eads 'I to energize the coil and polarize the magnet, The path of the magnetic flux travels towards the core face through the central core 3 and back through the perimeter or outer leg 4 of the magnet. Accordingly, when the magnetically susceptible member 5 is positioned adjacent the core face of the magnet I, the magnetic flux from the magnet traverses the adjacent regions of the member 5 making this member magnetically reverse in polarity to the adjacent pole faces of the magnet. The result is that the member 5 acts as an armature and is magnetically attracted to the magnet or vice versa, thus forming a closed magnetic path for the flux traveling from .the central core outwardly through the member 5 and back through the perimeter 4 of the magnet.

In practice, the member 5 may be a stationary track and the magnet I may be carried on an adjacent movable member which is guided along the track so that when the magnet is energized, the attraction between the track and the magnet acts to arrest the movement of the movable member 6 relative to the stationary track 5.

In its preferred form, the electro-magnetic lock to be hereinafter more fully described in connection with a tilt-table type X-ray apparatus, should be small enough and have sufficient power to provide positive magnetic locking action between the stationary and movable members of the apparatus. This type of action may be accomplished by constructing an electro-magnetic lock having locking forces of between 16 and 30 pounds against sliding motion. In .order to further enhance the arresting power of the `magnet and to overcome the slight amount of friction devel oped by residual magnetism, a cover 35 of ilexible material, such as neoprene, is provided for the magnet which projects approximately 1,64 oi an inch beyond the face of the core. The neoprene tace is preferably made in the form of a cylinder Whose walls insulate the coil fromthe core and whose face is the braking or arresting surface of the magnet. Since the neoprene has a greater co-eilicient of friction to steel than does steel to steel, the effort required to move a lock assembly is increased. Furthermore, the elasticity of the neoprene face results in a mushroomtype action which has a greater gripping power so that when the magnet is de-energized the neoprene, in returning -to its original state, acts as a spring and lifts the magnet free of the track or armature, thereby eliminating any undesirable effects of residual magnetism in the magnet core.

In the embodiment shown in Figs. 1 to 4, the magnet I is provided with annular grooves 8 on its external diameter for keying the magnet I to the supporting member 6. The supporting member 6 may be punched or otherwise provided with a hexagon hole as shown in Fig. 4 and the magnet I is inserted with snap rings Si in the annular grooves immediately adjacent the supporting member t. Tht spaces between the annular grooves S are suiciently large to allow the magnet I to float between the snap rings 9 and thereby be self-aligning. With this arrangement, the magnet I is attracted to the armature or track 5 when the coil is energized. However, it is apparent that other forms of construction may be utilized to carry out the same principle of operation. For example, the magnet I may be iixedly retained on the supporting member Il and the armature or track arranged to be movable.

Other embodiments of the electro-magnetic lock structure are shown in Figs. 5 and 6. In Fig. 5, the magnet I is shown xedly mounted on the supporting member and in Fig. 6, the magnet i is shown loosely carried adjacent the supporting member S against the action of a spring or resilient member.

The principle of the electro-magnetic lock is shown in the remaining drawings applied to a tilt-table type X-ray apparatus, carrying out the techniques of radiography and uoroscopy. Referring to Figs. 6, 7, and 8 a frame II supports a table i2 for tiltable movement relative to the frame. The table I2 is provided with a longitudinal track as shown by the dotted lines i3. An X-ray tube head I 4 including a shutter mechanism I5 and a luoroscopic screen unit It having a spot-film device Il are mounted on a supporting column I8 which is movably supported in a carriage It for longitudinal or crosswise positioning relative to the table I2.

The carriage I 9 is mounted for movement longitudinal of the table I2 on anti-friction rollers 2d which are carried in the track I3. The carriage I9 is also provided with a track 2! which extends within the carriage frame in a direction crosswise of the table I2. The supporting column I8 is also mounted on anti-friction rollers 22 for movement in the carriage track 2l crosswise on the table I 2.

In their' preferred form, each of the tracks I3 on the table and 2| in the carriage are provided with a magnetically susceptible member throughout their entire distance. The carriage I9 carries a magnet 23 of the type previously described which magnet may be remotely energized and controlled to lock against the track I3 and thereby arrest the longitudinal movement of the carriage relative to the table i2. The supporting column I3 is also provided with a magnet 2t adapted upon energization to coact in magnetic locking relation with the carriage track ZI to arrest crosswise movement of the supporting column I8 relative to the table I 2.l

instantaneously upon operating the control.

The spot nlm device Il, which is carried Within the uoroscopie unit I 6 above the table I2 is used by a radiologist to luoroscope a patient on the table so that the moment the radiologist observes pathology of interest, he may quickly record it on iilm. For example, in the investigation of a stomach for ulcers, the patient is usually required to swallow barium mean which is radio opaque and as the barium descends into the stomach, the radiologist may palpitate the stomach in order to force the barium into the crater of the ulcer. The moment he visualizes this condition, he brings the hlm over very rapidly and makes a record. rFhese iilms are usually small and as the barium descends into the stomach it is not Dossible to radiograph the entire tract on the spot film device. Furthermore, lms taken with the spot hlm device are not of the quality that can be attained by means of a bucky radiograph and it may be necessary to transfer the center of pathology from the fluorescent screen to a radiographic tube on an auxiliary tube stand. In the case of luoroscopy and spot-nlm operations, it is not necessary to place the patient in the exact center of the table. However, if a bucky radiograph is to be made, the patient must be centered on the table over the bucky diaphragm and associated film cassette. Accordingly, the carriage I9 is provided with electro-magnetic locks having least two types of action as will be hereinafter more fully described.

Referring to Figs. 12 and 14, the crosswise electro-magnetic lock 24 is shown connected through a mechanical centering switch 25 and a line switch 2 to a source of electrical energy. The centering switch 25 is spring operated and is mounted on the X-ray tube head I4 to cooperate with a notch 28 which is centrally located on the carriage i9 relative to the sides of the table I2 so that when the supporting column IS and the associated tube head Ill are centrally positioned crosswise in the table l2, the spring operated switch arm 2e is free to move into the notch 28 and close the energizing circuit to the crosswise electro-magnetic lock 213, thereby arresting further crosswise motion of the supporting column I8 relative to the table.

In accordance with the above described radiographic and iluoroscopic techniques, other forms oi' individual and combined action of the longitudinal and crosswise electro-magnetic locks may be desirable. For example, it may be desirable to have both the longitudinal and crosswise electro-magnetic lock-s operate simultaneously and On the other hand, the technique may require that neither of these locks be energized until the X- ray tube head and associated apparatus is centered on the table I2. Fig. 17 illustrates a control circuit which may be adapted for either of these types of operation, depending upon the po,- 'sitioning of a switch 29.

In this circuit, the longitudinal and crosswise electro-

magnetic locks

23 and 24 are shown. connected in parallel through a single pole, doublethrow switch 29 to a. source of electrical energy so that when the switch 29 is in the right-hand position, both of the electro-magnetic locks are simultaneously energized regardless of the yrelative positions of the controlled members. other side of the switch 29 is connected through the centering switch 25 to the parallel connected electro-magnetic locks, so that when the switch 29 is thrown to the. left-hand position, neither ,of the' electro-magnetic locks areenergized until The l the jX-ray tube head is centrally positioned cross- Wise of `the table I2. The technique of locking both electro-magnetic locks simultaneously regardless of the position of the controlled members would normally be used just before making an exposure with the spot film device, while the technique of with-holding the locking of these locks until the tube head is centrally positioned crosswise of the table would be used when transferring to a radiographic exposure. In the latter case, with the carirage I9 locked in the exact center of the table, the patient may be moved on the table until the part of which a bucky radiograph is to be be made is centered in the ra.- diograph screen. An auxiliary tube stand 10, shown in Fig. 31, may then be brought into place and centered with the fluoroscopic unit by means of either a mechanical or optical centering device not forming part of this invention and therefore not shown. After the auxiliary tube stand is thus centered, the carraige IS may be unlocked and moved out of the way as shown by the dotted lines I8A in Fig. 7.

One of the significant features of arresting the various motions of an X-ray apparatus by an electro-magnetic type lock is the variety of possible controls that may be accomplished with any given individual or combination of electromagnetic locks. Thus, in addition to the several embodiments of control circuits Ishown in Figs. 14 and 17, it may be desirable in the apparatus shown to provide the type of control associated with the circuit shown in Fig. 18. The switch 30 may be in the form of a double pole, double throw switch with a neutral position or it may be a push button type switch having a like number of poles and positions. rPhe continl technique resulting from operation of the switch 30 in Fig. 18 is such that when the switch 30 is in the lower position and engaging the lower respective contact members 3l and 32, the longitudinal electro-magnetic lock 23 is immediately energized to arrest the longitudinal motion of the carriage I9 relative to the table I2, while the crosswise lock 24 is not energized until the X- ray tube head I4 is centrally positioned crosswise on the table I2, whereupon the centering switch 25 operates to close the energizing circuit to the crosswise electro-magnetic lock 24. When the switch 30 is in the upper position to engage the

contact members

33 and 34, the centering switch 25 is excluded from the energizing circuit and both the longitudinal and crosswise electro-magnetic locks are immediately energized to simultaneously arrest both the longitudinal and crosswise movements of the supporting column I8 relative to the table I2.

As previously noted, the illustrated X-ray apparatus is a tilt-table type apparatus which may be tilted to intermediate angular or vertical positions relative to the supporting frame I I. When the table I2 is in the horizontal position shown in Fig. 7, the only forces of resistance to longitudinal motion of the supporting column I8 are the frictional forces between the rollers 2t and the track I3. However, when the table I2 is vertically positioned, as shown in Fig. 15, the weight of the 'supporting column I8 acts to aid downward motion and to restrain vertical motion of the column I9 along the longitudinal track. Accordingly, as shown in Fig. 15, in dotted lines a counterweight arrangement is provided to balance the vertical motion of the supporting column 19. The .counterw'eight arrangement may be of any suitable. form and. may comprise a r ing armatures 5I closed belt or cable 40 interconnecting the supporting column I8 with the weight 4I. The cable 40 may be supported within the table I2 by means of pulleys 42.

Referring now to Figs. 20, 21, 22, and 23, the fluoroscopic unit I6 may be horizontally positioned about a pivot 45 on the supporting column I8 to a position directly over or adjacent the side of the table I2, or in any intermediate position as indicated by the dotted lines I6A in Fig. 20. The uoroscopic unit I6 may also be provided with a magnetically susceptible armature 46 adjacent a magnet 41 on the supporting column I8, so that when the uoroscopic unit I6 is positioned over the table in working relation, it may be magnetically locked and retained in that position by virtue of the electro-magnetic lock. A suitable energizing circuit for the electro-magnetic lock, including a push-button control 48, is shown in Fig. 23.

The fluoroscopic unit I6 may also be mounted on a pivot 49 for vertical pivotal movement with relation to the supporting column I8 as shown in Fig. 24. The dotted lines ISB represent the parked or non-working position of the fluoroscopic unit I6. Referring to Fig. 25, two magnetically susceptible armatures 5i and 52 are shown positioned on one side of the vertical pivot 49 in spaced relation on the iiuoroscopic unit carriage 50 and extending over a pair of aligned magnets 53 and 54 on the iiuoroscope unit respectively. Thus, when the iluoroscopc unit I 6 is horizontally positioned over the table I2, the magnets 53 and 54 coaet with the correspondand 52 respectively to lock the rluoroscopic unit in this horizontal position. The force required to separate the horizontal magnetic locks is in the order of approximately lbs. each, and two of such electro-magnetic locks are sufficient to overcome the resistance of a patient lying on the table and pushing up against the uoroscopic unit I6. Another magnet 55 is mounted on the fluoroscope unit I6 on the other side of the pivot 49 to cooperate with an armature 56 carried on the carirage 5i! to lock the fluoroscope unit in the extended vertical position indicated by the dotted lines IBB in Fig. 24. A simple energizing circuit having pushbutton control with momentary contacts may be utilized to deenergize the electro-magnetic locks in either the horizontal or vertical positions.

In fluoroscopic spot lm examinations, and particularly in the study of the stomach, the barium meal must be forced into position and held there during exposure. This is usually done by mounting a cone 43 in the form of a hemisphere in the path of the central X-ray beam and applying pressure to the patient while at the same time palpitating the stomach to be sure that the radio opaque media will flow as desired and then holding the desired position by means of a compression cone. Accordingly, the iluoroscope unit I6 must be pressed forward against the patient and locked with compression during exposure to the spot lm. The electro-magnetic lock principle may likewise be adopted to accomplish this type of action in accordance with the arrangement shown in Figs. 28, 29, and 30, where the iluoroscopic carriage 50 is mounted for vertical movement along the supporting column I8 on anti-friction rollers 5l. The carriage 50 is provided with one or more magnets 6U which are adapted to cooperate in magnetic locking track 6I carried along the supporting column I8 9 throughout the desired distance of vertical movement of the carriage 50. The electro-magnetic looks 63 may be energized by means of the conveniently located switch 62, to arrest the movement of the carriage B and fluoroscopic unit IS in either direction. In this way, compression may be applied to the patient and maintained during a spot nlm fluoroscopic examination.

Inasmuch as the carriage 58 and fluoroscopic unit I3 are adapted for vertical movement along the supporting column I8, a counter-weight arrangement Which is similar to that described in relation to Fig. 15 is provided as shown in Figs. 28 and 29. The counter-weight 65 is connected to the carriage 50 through cables 66 which are looped over pulleys G1 on top of the supporting column I 8 to counter-balance the carriage movement.

The electro-magnetic lock control circuits in Fig. 17 or 18 may easily be adapted to include control of the electro-magnetic compression locks (i3 of Fig. 30 as shown in the control circuit arrangement of Fig. 19. The control resulting from operation of this circuit is such that when the switch 38 is in the lower position, the longitudinal electro-magnetic lock 23 instantaneously arrests that movement of the supporting column I8 while neither the crosswise electro-magnetic lock 24 nor the compression locks BIJ are energized until the supporting column is centrally positioned crosswise with respect to the table I2. With the switch in the upper position, all of the electro-magnetic locks are immediately energized regardless of the position of the controlled members.

As previously noted, an auxiliary X-ray tube stand may be utilized when employing the apparatus illustrated in the drawings for the technique of radiography. One embodiment of such a tube stand is illustrated in Fig. 31 in the form of a vertical stand 'IIJ positioned for movement along a track 'II which runs parallel to the table i2 and guided at the top by a trolley 12. In some instances, the tube stand I0 may be suspended from the trolley 12 without utilizing the track li at the base. An auxiliary X-ray tube carria-ge i3 is shown mounted for vertical movement on the tube stand 'l0 and is counter-balanced thereon by means of a counter-weight arrangement shown in dotted lines as embodying the counter-weight T4 with a cable 'I5 and pulley 16. An X-ray tube supporting arm 11 is mounted for rotation about a horizontal axis on the carriage 'I3 and carries an X-ray tube 18 which may be positioned along the supporting arm in accordance with the condition to be exposed.

The electro-magnetic lock principle is likewise adaptable to the various movements of the tube stand l@ and to the movements of each of the associated members relative to each other and the stand. Thus, as illustrated in Fig. 32, the tube stand 'Ic may be guided along the track TI by means of a carriage 'la which is supported by rollers or wheels 80. One or both of the rollers may be made of or provided with a magnetically susceptible material which will have magnetic locking attraction with a magnet 8| mounted on the carriage 'I9 adjacent the magnetically susceptible carriage roller 80.

The tube stand 'I0 is mounted for rotation about a Vertical axis on the carriage 19, and the mounting to the carriage is made through an electro-magnetic lock arrangement as illustrated in Fig. 33. In the preferred embodiment shown, the carriage 79 has a flat circular Journal plate 82 at the top adjacent the junction of the tube stand 1U with the carriage. A corresponding flange yor flat journal plate 83 is carried at the base of the tube stand l0 adjacent to and in aligned relation with the disc 82 on the carriage. The tube stand llange 83 carries a magnet 8d which upon energization magnetically locks with the disc plate 82 acting as an armature on the carriage 'I9 in any position of the tube stand relative to the carriage. Rotation of the tube stand 'I0 is limited by the stop 93 on the upper journal plate 83. Suitable remote controls and energizing circuits may be provided for the electro-magnetic locks 8l and 84 to effect individual or combined action in order to arrest movement of the carriage I9 or the tube stand 'l0 as desired.

The carriage 'I3 on the tube stand 'ID is also provided with an electro-magnetic lock 85, as shown in the dotted lines in Figs. 3l and 34, to arrest vertical movement of the carriage relative to the stand. The cooperating armature for the magnet 85 may, in its preferred form, embody a magnetically susceptible vertical track 86 carried along the tube stand 'i0 adjacent the niagnetic lock 85. Suitable anti-friction rollers 8l are provided by the carriage 73 to aid vertical motion of the carriage along the stand 10.

The end of the X-ray supporting arm TI, which is adjacent the tube stand l0, carries a flat disctype coupling and armature 38 which cooperates with the magnet 89 on the carriage i3. The disc armature 38 serves a dual purpose as an armature for the electro-magnetic lock 89 and as an indicating dial having markings 9| on the periphery which cooperate with a stationary pointer Sil on the carriage I3 to give a Visual indication of the angular displacement of the X-ray tube 'I8 from the initial position represented by the pointer 90, as best shown in Fig. 35. An energizing circuit for the electro-magnetic locks, including remote control means, may be incorporated into the apparatus to operate the locks individually, or in combination, to arrest separate or combined movements of the individual members of the apparatus.

As previously noted, it is at times desirable and necessary to transfer the center of pathology to the radiographic tube 18 in order to effect a bucky radiograph of the particular pathology under observation. The combined operation of the iiuoroscopic spot nlm and the bucky has been described in connection with Figs. 17 and 18, and the detailed construction of the bucky mechanism in the apparatus will hereinafter be more fully set forth in connection with Figs. 36 through 40.

Fig. 36 illustrates 'an assembly of the X-ray apparatus with the bucky carriage Iil and nlm cassette carrier IIlI centrally positioned within the table I2 in operating relation with the auxiliary or radiographic tube stand. The dotted lines, IBB illustrate the manner in which the fluoroscope supporting column I8 may be displaced from the region of radiographic operation by merely sliding the carriage I8 along the longitudinal track I3 and energizing the corresponding electro-magnetic lock to arrest the supporting column in an out-of-the-way position relative to the work area during a radiographic operation. The bucky carriage |88 is mounted on anti-friction rollers |02 which are adapted to traverse the longitudinal track I3 of the table.

The carriage supports the lm cassette carrier or tray IUI which is loosely carried there- 1-1-- in for movement crosswise of the table I2 as shown in Figs; 37 and' 3'8" where the extended crosswise position of the lm tray is shown in dotted lines' as |`0|A. The bucky carriage |00 also supports a bucky screen or' diaphragm |03 which is resiliently mounted at the top of the carriage so that either an articial or normal vibration of the apparatus will vibrate the bucky screen to effect its function in a manner well known in the art. The bucky carriage may be moved throughout the length of the table by towing the handle |04 extending from the film tray lill and urging the entire carriage in either direction along' the table l2 as desired.

As previously noted in connection with Figs. 17 and 18, thev positioning and centering of the bucky apparatus is a precise operation and once the setting is made and the tube stand 'i0' is locked in place, it is` desirable to lock the bucky carriage |00 in place to prevent inadvertent or unintentional misalignment which would require a readjustment of all the essential working members involved in the radiographic technique. Aocordingly, the Ducky carriage |00 is also provided with a magnet which cooperates with the magnetically susceptible track I3 on the table |21 Although the energizing circuit for this electro-magnetic lock may be remotely controlled after the manner of several other electro-magnetic locks in the apparatus, the preferred embodiment shown in Figs'. 37' and 39 illustrates an automatic type control in the form of a spring operated switch |05 which is mounted on the bueky carriage |00 so that a spring arm |07 extends in abutting relation with; one end of the lm tray l0 when the'trayv is in the extreme enclosed position within the carriage E00. Once the bucky carriage is properly centered and positioned on the table relative to the radiographic tube 18 and a lm cassette is inserted in the tray, the tray may be returned to itsA enclosed position within the carriage |00 so that the end which abuts the spring arm |01 of the switch |06 cle-- presses the spring arm downward and closes the energizing circuit illustrated in Fig. 40, to lock the electro-magnetic lock |05V to the track I'3 of the table, thereby arresting further movement of the carriage |00 relative to the table |2 and preventing inadvertent misalignment during the radiographic operation. By using this type of automatic control for the electro-magnetic lock |05, the bucky carriage is always locked when the lm tray |0| is in the radiographic position, but the moment the tray is withdrawn enough to clear the switch arm |01, the bucky carriage is unlocked and can be moved relative to' the table by urging or towing the handle I EN.

The electro-magnetic lock and its application to an X-ray apparatus in accordance with this invention, as illustrated by way of example in the ccompanying drawings and description, provides many distinct advantages over known types of X-ray apparatus by reason of providing conveniently located remote controls and eliminating the disadvantages inherent in the various adjustments and maintenance required for known types of mechanical locks. The fact that the electro-magnetic type lock may be electrically controlled also provides an unlimited variety of individual and combined operating characteristics for arresting individual and combined movements of a plurality of movable members relative to each other and to associated stationary members in any form of X-ray apparatus. Reference is made to our co-pending application. Serial. No.

aravaca? l2 205,088, led January 9,A 1951, entitled X-ray Ap# paratus and Control and relating to similar subject matter;

We have shown andr described what we consider the preferred embodiment of our invention along with suggested modified forms, and it will be obvious to those skilled in the art that other changes and modifications, particularly with respect to the construction of the electro-magnetic lock and its application to various forms of X-ray apparatus, may be made without departing from the scope of our invention as dened by the appended claims'.

We claim:

l. In an X-ray apparatus having a plurality of stationary structures, and a plurality of other corresponding structures movable relative thereto, each of said stationary structures having a magnetically susceptible member adjacent the desired positions of said corresponding movable structures respectively, a magnet having an energizing coil carried by each oi said movable structures, and electrical means for automatically energizing each of said magnet coils individually or in combination, whereby said magnet is attracted and adheres to a corresponding magnetically susceptible member to arrest further movement of said respective movable structures relative to the corresponding stationary structures in predetermined relation.

2. An electromagnetic lock comprising, a magnet having a central core and an energizing coil on said core, said magnet being hexagonal in cross section and having annular grooves spaced along the hexagonal corners respectively, a support having a cooperating hexagonal opening for said magnet, magnet mounting means including annular resilient members adapted to encircle said magnet, each of said annular members being seated in said annular grooves on the magnet and disposed in spaced relation on either side of said support, a magnetically susceptible armature and. a support therefor, means effecting relative motion between said magnet and armature supports, electrical means for energizing said coil when said magnet is positioned adjacent said armature tocause mutual magnetic attraction and adhesion therebetween and thereby arrest further relative motion between said supports.

3. In any electro-magnetic lock of the type described, a magnet having a core and energizing coil therefor, said magnet being hexagonal in cross section and having annular grooves spaced along the hexagonal corners thereof, a support having a cooperating hexagonal opening for said magnet, said support having a cross section in the direction of the opening of less dimension than the spacing between the annular grooves on said magnet, a pair of split annular members, each of said annular members having an inner diameter equal to the inner diameter between diametrically opposed annular grooves of said magnet, and having an outer diameter greater than thel diameter of the hexagonal opening through said support, one of said split annular members being disposed within the annular grooves on the magnet on either side of said support, thereby restricting movement of said magnet relative to the support beyond the limiting positions of said. annular members in a direction normal to said support, a magnetically susceptible armature and a support therefor, means effecting relative motion between said magnet and armature-supports, electrical means for enersadfcoil-when said magnet is positioned i3 adjacent said armature to cause said magnet to rbe attracted and adhere to said armature and thereby arrest further relative motion between said supports.

4. An electro-magnetic lock comprising a magnet having a core and anenergizing coil therefor, said magnet being hexagonal in cross section and having annular grooves spaced along the hexagonal corners thereof, a support having a cooperating hexagonal opening for said magnet, a magnetically susceptible armature and a support therefor positioned adjacent said magnet support, a pair of split annular members, each of said annular members having an inner diameter equal to the inner diameter between diametrically opposed annular grooves on said magnet and having an outer diameter greater than the diameter of the hexagonal opening in said support, each of said split annular members adapted to be seated within said spaced annular grooves on the magnet on opposite sides of said support, the spacing between the said spaced annular grooves along each hexagonal corner of said magnet being greater than the cross section of said support in the direction of said hexagonal opening, thereby allowing relative displacement between said magnet and support between said limiting annular members toward intimate contact with said armature, means eiecting relative motion between said magnet and armature supports, electrical means for energizing said coil when said magnet is positioned adjacent said armature to cause said magnet to be attracted and adhere thereto and thereby arrest further relative motion between said support, and resilient insulating means surrounding said coil and covering the portion of said magnet adjacent the armature, said insulating cover coacting with said armature to increase the coefficient of friction between said magnet and armature when said magnet is energized and to urge said magnet and armature apart when said magnet is deenergized.

5. In an X-ray apparatus having a plurality oi structures freely supported for movement relative to each other, a plurality of electro-magnetic looks coacting between different relatively movable structures to lock them together against displacement, each lock including a magnetically susceptible member carried by one structure and a magnet having an energizing coil carried by another structure in operative proximity to the corresponding magnetically susceptible mem'ber, means permitting displacement of each magnet for physical contact with the corresponding magnetically susceptible member in response to a magnetic attraction therebetween, and means for selectively energizing the -coils to create the magnetic attraction and lock the corresponding structures together in predetermined position relative to each other.

6. In an X-ray apparatus having a stationary member and another member freely supported for longitudinal and crosswise movement relative to said stationary member, a magnetically susceptible guide disposed parallel to the longitudinal and crosswise direction of movement respectively, a pair of magnets each having an energizing coil and each carried by the movable member adjacent the longitudinal and -crosswise guide respectively, means permitting displacement of each magnet toward physical contact with the corresponding guide in response to a magnetic attraction therebetween, and means for simultaneously energizing each of said enerrelative to the stationary member, a plural po-' gizing coils to create the magnetic attraction andlock the movable member in a selected longitudinal and crosswise position relative to the stationary member.

7. In an X-ray apparatus having a stationary member and another member freely supported for longitudinal and crosswise movement relative to said stationary member, a magnetically susceptible guide disposed parallel to the longitudinal and crosswise direction of movement respectively, a pair of magnets each having an energizing coil and each carried by the movable mem` ber adjacent the longitudinal and crosswise guides respectively, means permitting displacement of each magnet toward physical contact with the corresponding guide in response to a magnetic attraction therebetween, and means: automatically responsive to said movable mem-v ber being centrally positioned in the crosswise direction to simultaneously energize each ofA said energizing coils and create the magnetic attraction to lock the movable member in a selected'V longitudinal and crosswise position relative to thej stationary member.

8. The apparatus of claim 7 wherein the means for energizing the coils includes an energizing circuit having a normally open switch adapted' to be closed by the movable'member when the latter is positioned centrally in a crosswisedirectionrelative to the stationary member.

9. In an X-ray apparatus having a stationary member and another member freely supportedV for longitudinal and crosswise movement relative to a stationary member, a magnetically sus ceptible guide disposed parallel to the longitudinal and crosswise direction of movement re-' sition switch in said energizing circuit, said switch in one position connecting each of the coils in the circuit and in another position connecting only the coil adjacent the longitudinal guide in the circuit, and means cooperating with'f the switch in the latter position in response to said movable member being centrally positioned crosswise relative to the stationary member to automatically connect the coil adjacent the crosswise guide in the energizing circuit. Y

, 10. In an X-ray apparatus having a stationary member and a plurality of other members freely' supported for movement relative to each other and to the stationary member, one of said movable members being mounted for longitudinal and crosswise movement relative to the stationary member, another of said movable members being mounted for vertical motion along said iirstmovable member, a magnetically susceptible guide disposed parallel to the longitudinal and crosswise directions of movement respectively of the rst movable member, another magnetically susceptible guide disposed parallel to the vertical motion vof said other movable member, a plurality of.magnets each having an energizing coil and each operably disposed on a member for` coaction with the ,guide corresponding tol` the,

direction' of relative movement of said member,

meansAV permitting displacement of each magnet for vphysical contact with the vcorresponding guide in response to a magneticattraction therebetween, and electrical means for selectively energizing each of the magnet coils to create the magnetic attraction and lock the corresponding movable members in selected longitudinal, cross- Wise and vertical positions respectively.

11. In an X-ray apparatus having a stationary member and a plurality of other members freely supported for movement relative to each other and to the stationary member, one of said movable members being mounted for longitudinal and crosswise motion relative to the stationary member, a second movable member mounted for vertical motion along said rst movable member, a third movable member mounted for pivotal horizontal and vertical positioning relative to said second movable member, a nrst magnetically susceptible guide operably disposed between the stationary member and the rst movable member and parallel to the longitudinal and crosswise relative motions between said members, a second magnetically susceptible guide disposed between the second and iirst movable member and parallel with the vertical relative motion therebetween, a third magnetically susceptible guide operable disposed between the second and third movable members in a horizontal and vertical plane respectively, a. plurality of magnets each having an energizing coil and each operably disposed on a corresponding member for coaction with the magnetically susceptible guide corresponding to the direction relative of movement between the corresponding members, means permitting displacement of each magnet toward physical contact with the corresponding guide in response to a magnetic attraction therebetween, and electrical means for selectively energizing each oi thev magnet coils to create the magnetic attraction and to lock the corresponding movable member in a selected position in predetermined relation to each of the other members.

l2. In an X-ray apparatus having a stationary member and a plurality of other members freely supported for movement relative to each other and thestationary member, a first movable member mounted for longitudinal and crosswise motion relative to the stationary member, another movable member mounted for vertical motion along the first movable member, a magnetically susceptible guide disposed between the first movable member' and the stationary member and parallel to the longitudinal and crossvvise direction of relative movements, a second magnetically susceptible guide disposed between said other movable member and the first movable member and parallel to the vertical direction of relative movement, a pluralityv of magnets each having an energizing coil and each operably disposed on a member adjacent a guide corresponding to the direction of relative movement between the corresponding members, means permitting displacement of each magnet toward physical contact with the corresponding guide in response to a magnetic attraction therebetween, an electrical energizing circuit for each of the magnet coils, a switch for connecting the magnet coil adjacent the longitudinally disposed guide in the energizing circuit to lock the rst movable member in a selected longitudinal position relative to the stationary member, and means automatically responsive to the central positioning of the rst movable member in a crosswise direction relative to the stationr? member and coacting with the 16 switch in the energizing circuit to selectively energize each of the other magnet coils and thereby automatically lock the first movable member in central position in the crosswise direction and lock the other movable member in a predetermined vertical position.

13. In an X-ray apparatus having a stationary member and plurality of other members freely supported for movement relative to each other and to the stationary member, a first movable member mounted for longitudinal and crosswise motion 'relative to the stationary member, another movable member mounted for vertical motion along said first movable member, a magnetically susceptible guide disposed between the first movable member and stationary member and parallel to the longitudinal and crosswise directions of relative movement, a second magnetically susceptible guide disposed between said other movable member and the rst movable member and parallel with the vertical relative movement, a plurality of magnets each having an energizing coil and each disposed on a relatively movable member adjacent the guide corresponding to the relative direction of movement of said member, means permitting displacement of each magnet toward physical contact with the corresponding guide in response to a magnetic attraction therebetween, an electrical energizing circuit for the magnet coils, a plural-position switch in said energizing circuit, said switch coacting in one position on the circuit to simultaneously energize all of the magnet coils and thereby lock each of the relatively movable members in selected positions along their direction of relative movement and in predetermined relation to each other, said switch coacting in the circuit in another position to energize only the magnet coil corresponding to the longitudinal guide to lock the first movable member in a predetermined longitudinal position, and means coacting with the switch in the latter position to automatically energize the other magnet coils consequent upon the first movable member being centrally positioned in a crosswise direction relative to the stationary member, thereby locking the first movable member in central position in a crosswise direction and loclring the second movable member in a predetermined vertical position.

14. An electro-magnetic lock comprising a magnet having an outer core portion enclosing an inner core portion and spaced therefrom by a recess extending inwardly from one face of the magnet, an energizing coil disposed in the recess about the inner core portion, a support for said magnet, a magnetically susceptible armature and a support therefor, means effecting relative motion between the magnet and the armature support, electrical means for selectively energizing said coil when the magnet is positioned adjacent the armature to cause mutual magnetic attraction therebetween and thereby arrest further relative motion between the supports, and elastic material for insulating the coil in the recess, said material projecting outwardly from the recess beyond said one magnet face for frictional coaction with said armature when energized and for resilient coaction with said armature to urge the magnet away when deenergized.

15. An electromagnetic lock comprising, a magnet having an outer core portion enclosing an inner core portion and spaced therefrom by a recess extending inwardly from one face of the magnet, an energizing coil disposed in the recess about the central core portion, a support for said magnet, means for mounting the magnet to prevent relative motion between said magnet and magnet support in the plane of the support, a magnetically susceptible armature and support therefor, means for effecting relative motion between the magnet and armature supports, electrical means for selectively energizing the coil when said magnet is positioned adjacent the armature to cause mutual magnetic attraction therebetween and thereby to arrest further relative motion between the supports, an elastic insulating material enclosing the coil in the recess and projecting outwardly from the recess and beyond said one magnet face for coaction with said armature adapted to aid the magnet arresting action when energized and to resiliently urge the magnet away from the armature when deenergized.

16. An electromagnetic lock comprising, a hexagonally shaped magnet having an outer core portion enclosing an inner core portion and spaced therefrom by an annular recess extending inwardly from one face of the magnet, an energizing coil disposed in the recess about the central core portion, a support having a cooperating hexagonal opening for holding the magnet against rotation therein, means for maintaining axial alignment of the magnet in the support opening, a magnetically susceptible armature and a support therefor, means for effecting relative motion between the magnet and armature supports, electrical means for selectively energizing the coil when said magnet is positioned adjacent the armature to cause mutual magnetic attraction therebetween and thereby arrest further relative motion between the supports, an elastic insulating material enclosing the coil in the recess and projecting outwardly from the recess and beyond said one magnet face for coaction with the armature adapted to aid the magnet arresting action when energized and to urge the magnet away from the armature when deenergized.

17. An electromagnetic lock comprising a inagnet having an outer core portion substantially enclosing an inner core portion and spaced therefrom by a recess extending inwardly from one face of the magnet, an energizing coil disposed in the recess about the inner core portion, a magnetically susceptible armature, means for supporting the magnet and armature in spaced relation for relative movement, means for energizing the coil to cause magnetic attraction and coaction between the magnet and armature, and elastic material for insulating the coil in the recess and projecting outwardly beyond said one magnet face for coaction with said armature adapted to aid the magnetic coaction when the magnet is energized and to aid the release of the magnet from such coaction when deenergized.

18. An electromagnetic lock comprising a magnet having an energizing coil thereon, a magnetically susceptible armature, means for supporting the magnet and armature in spaced relation and for displacement towards and away from physical contact with each other in response to a magnetic attraction therebetween, means for connecting the magnet coil to a source of electrical energy to create the magnetic attraction and lock the magnet and armature together, and electrical insulation between the magnet and the coil projecting into the space between the magnet and armature, said msulation being elastic and having 'a greater coeincient of friction with the armature than the magnet and adapted to increase the locking action tnerebetween when the magnet is energized and to aid the release of the magnet from the armature when deenergized.

19. In an X-ray apparatus having a pair of structures mounted i'or movement relative to each other and adapted to be positioned in predetermined relation to each other Ior cooperative performance to produce a selected unitary result, a magnetically susceptible member carriecl by one structure and a magnet having an energizing coil carried by the other structure in operative proximity to the member, means coacting between the magnet and member to permit displacement towards physical contact with each other in response to a magnetic attraction therebetween, and means for selectively energizing the magnet coil to create the magnetic attraction between the magnet and member and lock them together against relative movement when they are positioned into the said predetermined relation to each other.

2i). An X-ray apparatus having a stationary structure and another structure movable relative thereto and adapted to be moved into a predetermined position for cooperative performance with the stationary structure to produce a selected unitary result, a magnetically susceptible member carried by the stationary structure and a magnet having an energizing coil carried by the movable structure in operative proximity to the magnetically susceptible member, means coacting between the magnet and the magnetically susceptible member to permit displacement toward physical contact with each other in response to a magnetic attraction therebetween, and means for selectively energizing the magnet coil to create a magnetic attraction between the magnet and the magnetically susceptible member and lock them together against relative movement when the movable structure is moved into the said predetermined position.

ROBERT J. STAVA. WALTER G. REININGER,

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,207,151 Hirsheld July 9, 1940 2,208,258 Grobe July 16, 1940 2,255,798 Mason Sept. 16, 1941 2,259,036 Goldeld et al Oct. 14, 1941 2,426,241 Rodman Aug. 26, 1947 2,440,420 Van Eps Apr. 27, i948 2,526,879 Kizaur Oct. 24, 1950 FOREIGN PATENTS Number Country Date 457.540 Great Britain Nov. 30, 1936