US3676683A

US3676683A - Dental x-ray head

Info

Publication number: US3676683A
Application number: US889503A
Authority: US
Inventors: Cornelius Keith Vandervelden
Original assignee: Litton Medical Products Inc
Current assignee: Litton Medical Products Inc
Priority date: 1969-12-31
Filing date: 1969-12-31
Publication date: 1972-07-11
Anticipated expiration: 1989-07-11
Also published as: DE2052626A1; NL7015996A

Abstract

A dental X-ray head having a bucket-shaped end and an exaggerated cone-shaped end. The bucket-shaped end is connected to a suspension system for supporting the dental X-ray head and contains a high voltage transformer and various connections thereto, while the relatively smaller exaggerated cone-shaped end houses an X-ray tube and the contour of the exaggerated coneshaped end follows the slope of the electrical potential established across the X-ray tube.

Description

[451 July 11,1972

2,909,664 10/1959 Zunicketal............................

[54] DENTAL X-RAY HEAD [72] Inventor:

Cornelius Kc vllldfl'vddfll, Kansas PrimaryExaminer-James W. Lawrence C y, Assistant Examiner-C. E. Church Attorney-Franklin D. .lankosky, Alfred B. Levine, Richard Zentner and Alan C, Rose [73] Assignee:

[22] Filed: Dec. 31, 1969 ABSTRACT A dental X-ray head having a bucket-shaped end and an exaggerated cone-shaped end. The bucket-shaped end is connected to a suspension system for supporting the dental X-ray head and contains a high voltage transformer and various con nections thereto, while the relatively smaller exaggerated cone-shaped end houses an X-ray tube and the contour of the exaggerated cone-shaped end follows the slope of the electrical potential established across the X-ray tube.

9 Claims, 3 [kawing Figures 5 3 55M95 35 :3 1321 3. .33 I. 0 m

w mm

mm M m m" i m I c 1 u "m R M m m I "I a c. a

A U .m

UNITED STATES PATENTS 2,307,612 Westendorp........................,....250/87 PATENTEDJUL 1 1 I972 33, 6 76 6 8 3 SHEET 10F 2 DENTAL X-RAY HEAD FIELD OF THE INVENTION This invention relates to dental X-ray heads and more particularly to a dental X-ray head having an exaggerated coneshaped portion for housing an X-ray tube.

DESCRIPTION OF THE PRIOR ART In order for a dentist or a dental x-ray technician to consistently obtain a series of high quality dental radiographs, the patient must remain quite still throughout the exposure to the entire series. A patient can normally remain still during most of the series of dental radiographs; however, for various parts of the series, the patient must place himself in a awkward, and sometimes uncomfortable or painful position, so as to enable a particular area to be X-rayed. Thus, for some particular series of dental radiographs, it is extremely difficult for the patient to remain sufficiently stationary throughout the series so as to obtain a complete, high quality series of dental radiographs. The most recognized reason for a patient having to place himself in such an awkward position is the lack of a compact dental X-ray head, particularly in the 90 kilovolt dental X-ray class.

The prior art dental X-ray heads in the 90 kilovolt dental X- ray class have been quite bulky. The patient'being X-rayed had to place himself in awkward positions, thus quite often the patient would move during an exposure and as a result of such movement one or more of the radiographs would be of very poor quality. Therefore, either part of the series of the dental radiographs had to be re-done or, because of the poor quality of the dental radiograph, an inaccurate diagnosis would be made. Typically, such dental X-ray heads were basically comprised of an X-ray tube, a high voltage transformer, and a filament transformer. The maximum electrical potential established across the X-ray tube was approximately I kilovolts wherein one end of the X-ray tube was placed at a positive 50 kilovolt potential and the other end at a negative kilovolt potential. Such a design necessitated that the area between the X-ray head housing and the X-ray tube had to be large enough along the entire surface of the X-ray tube to ensure that the electrical potential established was not shorted to the X-ray housing.

In addition, since both ends of the X-ray tube were at a 50 kilovolt potential, the filament transformer had to be at a 50 kilovolt potential, thus making it highly impractical to place the filament transformer anywhere but inside of the X-ray head. Since the X-ray head is sealed in order to retain the insulating medium, any breakdown of an additional component within the dental X-ray head, such as a breakdown of the filament transformer, involved expensive, complex, and time consuming repairs.

Accordingly, it is an object of the present invention to provide a novel dental X-ray head which ensures that an entire series of dental radiographs may be consistently obtained.

It is a further object of the present invention to provide a novel dental X-ray head which is compact and allows for complete accessibility of the X-ray beam to an area under observation without placing the patient in an awkward or unnatural position.

It is a still further object of the present invention to provide a novel dental X-ray head wherein the X-ray tube is located in a relatively smaller portion of the X-ray head which is ofiset from the main portion of the X-ray head.

It is another object of the present invention to provide a novel dental X-ray head wherein the X-ray tube is located in an elongated, cone-shaped portion of the X-ray head.

It is still another object of the present invention to provide a novel dental X-ray head wherein the filament transformer for the X-ray tube is located remote from the dental X-ray head.

SUMMARY OF THE INVENTION A dental X-ray head having a bucket-shaped end and an exaggerated cone-shaped head. The dental X-ray head is supported by a suspension system that is connected to the bucketshaped end of the dental X-ray head. The bucket-shaped end contains a high voltage transformer and various connections thereto. The relatively smaller exaggerated cone-shaped end houses an X-ray tube and the contour of the exaggerated cone-shaped end follows the slope of the electrical potential established across the X-ray tube. The directly heated cathode of the X-ray tube is located at the smaller end of the exaggerated cone-shaped end and is maintained at a zero electrical potential. Thus, the filament transformer may be located remote from the X-ray head.

BRIEF DESCRIPTION OF THE DRAWINGS Additional objects, advantages, and characteristic features of the present invention will become readily apparent from the following detailed description of preferred embodiments of the invention when considered in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a dental X-ray head with a portion of the X-ray head being cut away to expose the X-ray tube, in accordance with the present invention;

FIG. 2 is a perspective view of a typical prior art dental X- ray head, wherein the respective locations and sizes of various components of such a dental X-ray head are illustrated; and

FIG. 3 is a side view of the X-ray head of FIG. I, wherein the housing is partially cut away to expose the X-ray tube, the high voltage transformer and various connections thereof, in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, there is shown a perspective view of a dental X-ray head 10, in accordance with the present invention, which includes an exaggerated cone-shaped end 11 and a bucket-shaped end 12. The dental X-ray head 10 is supported by a trunion arm 13 which is part of a suspension system, not shown. The trunion arm 13 is attached to the bucket-shaped end 12 of the dental X-ray head 10, as can be seen by referring to FIG. 3. A portion of the housing of the exaggerated cone-shaped end 11 is shown cut away so as to expose an X-ray tube 14. An X-ray beam 14a is shown directed out of the exaggerated cone-shaped end 11 through an X-ray collimator 11a.

Referring now to FIG. 2 there is shown a typical prior art dental X-ray head 50 which is supported by a yoke 51. The cylinder 52 represents an X-ray tube. Since the opposite ends of the X-ray tube 52 were typically maintained at opposing 50 kilovolt potentials, the surface along the entire length of the X-ray tube 52 had to be positioned sufficiently away from the housing of the X-ray head 50 to ensure that shorting of the established electrical potential to the housing did not occur. Thus, a cylindrical shaped volume of insulation, as illustrated by the dashed lines designated 53, had to be maintained around the X-ray tube 52. Such insulation 53 is usually an oil. In addition to the relatively large amount of volume that was taken up by the insulation 53,-the prior art X-ray heads included not only a high voltage transformer, as illustrated by the dashed lines 54, but also included a filament transformer as illustrated by the dashed lines 55. It was necessary to include the filament transformer 55 in the X-ray head 50 because the cathode of the X-ray tube 52 was maintained at a 50 kilovolt potential and it would be highly impractical, and potentially dangerous, to place the filament transformer 55 anywhere but within the X-ray head 50.

Referring now to FIG. 3, there is shown a side view of the dental X-ray head 10 of FIG. 1 in accordance with the present invention. As in FIG. 1, a portion of the exaggerated coneshaped end 11 of the X-ray head 10 is cut away to expose the X-ray tube 14. In the present invention, instead of having both of the opposite ends of the X-ray tube at a high electrical potential, the cathode 14b is placed at ground potential and the anode Me is placed at an electrical potential of approximately lOO kilovolts. Therefore, since the cathode 14b is at a ground potential, that end of the X-ray tube may be placed relatively close to the housing of the X-ray head 10. On the I other hand, since the anode 14c of the X-ray tube 14 is at an electrical potential of approximately 100 kilovolts, the spacing between the anode end of the X-ray tube 14 and the housing of the X-ray head must be relatively large. Therefore, as can be readily seen from FIG. 3, there is a relatively small distance between the cathode end 14b of the X-ray tube 14 and the housing of the X-ray head 10 as compared to the distance between the anode end 140 of the X-ray head 10.

Since the cathode end 14b is at a ground potential and the anode end 140 is at an electrical potential of approximately 100 kilovolts, the contour of the housing of the X-ray head 10 may follow the slope of the electrical potential established across the X-ray tube 14. Thus, the exaggerated cone-shaped end 11 may be constructed as illustrated. By placing the cathode end 14b, or in other words, the end of the X-ray tube 14 which is farthest away from the bucket-shaped end 12 of the X-ray head 10, at a ground potential, the business or work-' ing end of the-X-ray head 10 may be relatively smaller than the portion of the X-ray head 10 containing the transformer and connection thereto. Thus, the dentist or X-ray technician may easily manipulate the exaggerated cone-shaped end 11 of the X-ray head 10 in close proximity of the area under observation so that the patient does not have to be placed in an awkward or uncomfortable position during the taking of a series of dental radiographs. Therefore, the patient can remain relatively still throughout the taking of the entire series of dental radiographs which in turn will ensure high quality dental radiography.

in another embodiment of the present invention, another portion of the housing of the Xray head 10 is cut away to expose an area to illustrate the high voltage transformer 15a. As illustrated, the area 15 is located within the bucket-shaped portion 12 of the X-ray head 10. Since the cathode 14b is not at a 50 kilovolt potential but rather, at a ground potential, it is not necessary to have a filament transformer at an electrical potential of approximately 50 kilovolts. Therefore, it is not necessary to have a filament transformer within the X-ray head as in the prior art. Thus, only connecting means 14f, shown coupled to the cathode 14b need to be provided within the X-ray head 10. The connecting means 14f may be connected to a filament transformer, not shown, located at a place remote from the X-ray head 10.

Thus, although the present invention has been shown and described with reference to particular embodiments, such as X-ray heads having a bucket-shaped end for enclosing a high voltage transformer, nevertheless, various changes and modifications obvious to a person skilled in the art to which the invention pertains, for example, an X-ray head having a cylindrical-shaped end for housing a high voltage transformer,

are deemed to lie within the spirit, scope and contemplation of the invention as set forth in the claims.

What is claimed is: l. A high voltage X-ray apparatus for use in X-raying in limited spaces comprising:

an X-ray tube having first and second electrodes, means for holding said first electrode at a potential close to ground potential, and means for generating high voltage for application to said second electrode;

a movable head, having an outer enclosure, supporting said X-ray tube with said first electrode located immediately adjacent said enclosure, said enclosure being generally conical in shape near. said X-ray tube and gradually increasing in its spacing from said X-ray tube from immediate proximity in the vicinity of said first electrode to a substantial spacing in the vicinity of said second high voltage electrode in accordance with the slope of the electrical potential from said first electrode to said second high voltage electrode; and

means for movably supporting said head so that it may be positioned where the portion of the head adjacent said first electrode is close to the body of a patient. 2. A X-ray apparatus as defined in claim 1 wherein the first electrode is the cathode and means are provided for connecting the cathode to a filament power supply remote from the movable head.

3. An X-ray apparatus as defined in claim 1 wherein said head supporting means is connected to said head at an area which is substantially offset from said X-ray tube.

4. An X-ray apparatus as defined in claim 1 wherein the movable head has one cone-shaped end which supports the X- ray tube, and wherein the other end of the head is bucket shaped and is of greater cross-section than said cone-shaped end.

5. An X-ray apparatus as defined in claim 4 wherein a high voltage transformer for providing anode potential is located in said bucket shaped end of the movable head.

6. An X-ray apparatus as defined in claim 1 wherein an X- ray collimator is provided near one end of the head where the head enclosure is immediately adjacent said first electrode, and wherein said head supporting means is connected to the opposite end of said head.

7. A high voltage X-ray apparatus comprising:

an X-ray tube having an anode and a cathode, said cathode being maintained close to ground potential, and means for supplying high voltage to said anode;

a movable head enclosing said X-ray tube, said movable head having a housing contoured to provide spacing between said housing and said X-ray tube in a relationship to the slope of the potential established across said X-ray tube, transformer means also enclosed in said head consisting only of a high voltage transformer for providing anode voltage;

means for connecting a remotely located filament transformer to said cathode; and

means for movably supporting said head to direct X-rays from said X-ray tube in desired directions.

8. A high voltage X-ray apparatus as defined in claim 7 wherein said head has a small conical end in which the X-ray tube is located, and a large relatively bulky end to which the supporting means is rotatably secured.

9. An X-ray apparatus as defined in claim 7 wherein the X- ray head is tapered from one end containing said X-ray tube to the other larger end containing said high voltage transformer, and wherein said supporting means is rotatably attached to the head at its larger end.

Claims

1. A high voltage X-ray apparatus for use in X-raying in limited spaces comprising: an X-ray tube having first and second electrodes, means for holding said first electrode at a potential close to ground potential, and means for generating high voltage for application to said second electrode; a movable head, having an outer enclosure, supporting said X-ray tube with said first electrode located immediately adjacent said enclosure, said enclosure being generally conical in shape near said X-ray tube and gradually increasing in its spacing from said X-ray tube from immediate proximity in the vicinity of said first electrode to a substantial spacing in the vicinity of said second high voltage electrode in accordance with the slope of the electrical potential from said first electrode to said second high voltage electrode; and means for movably supporting said head so that it may be positioned where the portion of the head adjacent said first electrode is close to the body of a patient.

2. A X-ray apparatus as defined in claim 1 wherein the first electrode is the cathode and means are provided for connecting the cathode to a filament power supply remote from the movable head.

4. An X-ray apparatus as defined in claim 1 wherein the movable head has one cone-shaped end which supports the X-ray tube, and wherein the other end of the head is bucket shaped and is of greater cross-section than said cone-shaped end.

6. An X-ray apparatus as defined in claim 1 wherein an X-ray collimator is provided near one end of the head where the head enclosure is immediately adjacent said first electrode, and wherein said head supporting means is connected to the opposite end of said head.

7. A high voltage X-ray apparatus comprising: an X-ray tube having an anode and a cathode, said cathode being maintained close to ground potential, and means for supplying high voltage to said anode; a movable head enclosing said X-ray tube, said movable head having a housing contoured to provide spacing between said housing and said X-ray tube in a relationship to the slope of the potential established across said X-ray tube, transformer means also enclosed in said head consisting only of a high voltage transformer for providing anode voltage; means for connecting a remotely located filament transformer to said cathode; and means for movably supporting said head to direct X-rays from said X-ray tube in desired directions.

9. An X-ray apparatus as defined in claim 7 wherein the X-ray head is tapered from one end containing said X-ray tube to the other larger end containing said high voltage transformer, and wherein said supporting means is rotatably attached to the head at its larger end.