System for, and method of, irradiating articles particularly articles with variable dimensions

Information

  • Patent Grant
  • 6608882
  • Patent Number
    6,608,882
  • Date Filed
    Wednesday, June 13, 2001
    23 years ago
  • Date Issued
    Tuesday, August 19, 2003
    21 years ago
Abstract
Articles move on a conveyor mechanism in a first direction past a radiation source for an irradiation of the articles (by e.g., an electron beam, x-rays or gamma rays) by radiation moving in a second direction substantially perpendicular to the fires direction. The distance between the radiation source and the articles on the conveyor mechanism may be adjusted to provide for the irradiation of each position in the articles and to minimize the amount of the radiation which does not pass into the articles. The adjustment may be made by (1) adjusting the position of the radiation source in a particular direction corresponding to the direction of the radiation source and the articles on the conveyor mechanism, (2) actuating an individual one of a plurality of conveyors for moving the articles past the accelerator, each conveyor being separated from the radiation source by a distance different from the distance of the other conveyors from the radiation source or (3) repositioning the articles on a single conveyor in the particular direction. The distance between the radiation source and the conveyor mechanism may be varied dependent upon changes in the dimension of individual articles relative to the dimension of other articles, in a direction substantially perpendicular to (a) the direction of the radiation source and (b) the path of movement of the articles on the conveyor mechanism. Instead of irradiating a single article at any one time, the system may simultaneously irradiate a batch or stack of articles of the same or different sizes.
Description




This invention relates to apparatus for, and methods of, irradiating articles such as food, drugs and medical instruments and implements. The invention particularly relates to apparatus for, and methods of, applying radiation to articles of different dimensions or to batches or stacks of articles of the same or different dimensions in a manner such that substantially all of the radiation is used to sterilize the articles and such that all of the positions of the articles receive proper amounts of irradiation.




BACKGROUND OF THE PREFERRED EMBODIMENTS OF THE INVENTION




It has been known for some time that drugs and medical instruments and implements have to be sterilized so that they will not cause patients to become ill from harmful bacteria when they are applied to the patients. Systems have accordingly been provided for sterilizing drugs and medical instruments and implements. The drugs and the medical instruments and implements have then been stored in sterilized packages until they have been ready to be used.




In recent years, it has been discovered that foods can carry harmful bacteria if they are not processed properly or, even if they are processed properly, that the foods can harbor such harmful bacteria if they are not stored properly or retained under proper environmental conditions such as temperature. Some of these harmful bacteria can even be deadly.




For example, harmful bacteria have been discovered in recent years in hamburgers by one of the large hamburger chains. Such harmful bacteria have caused a number of purchasers of hamburgers from stores in the chain to become sick. As a result of this incident and several other similar incidents, it is now recommended that hamburgers should be cooked to at least a medium state rather than a medium rare or rare state.




Similarly, harmful bacteria have been found to exist in many chickens that are sold to the public. As a result of a number of incidents which have recently occurred, it is now recommended that all chickens be cooked so that no blood is visible in the cooked chickens.




To prevent incidents such as discussed in the previous paragraphs from occurring, various industries have now started to irradiate the foods that are sold to the public. This is true, for example, of hamburgers and chickens. It is also true of fruits, particularly fruits which are imported from foreign countries. Radiation has also been used for sprout inhibition, shelf life extension and modification in the properties of materials.




In previous years, gamma rays have generally been the preferred medium for irradiating articles. The gamma rays have been obtained from a suitable material such as cobalt and have been directed to the articles to be irradiated. The use of gamma rays has provided certain disadvantages. One disadvantage is that irradiation by gamma rays is slow. Another disadvantage is that irradiation by gamma rays is not precise. This results from the fact that the strength of the source (e.g. cobalt) of the gamma rays decreases over a period of time and that the gamma rays cannot be directed in a sharp beam to the articles to be sterilized. This prevents all of the gamma rays from being useful in irradiating the articles.




In recent years, electron beams have been directed to articles to irradiate the articles. Electron beams have certain advantages over the prior use of gamma rays to irradiate articles. One advantage is that irradiation by electron beams is fast. Another advantage is that irradiation by electron beams is relatively precise because the strength of the electron beam remains substantially constant even when the electron beam continues to be generated over a long period of time.




Irradiation by electron beams has a limitation which sometimes may be significant. Electrons in the electron beams have mass. As the electrons in the beam travel through the article to irradiate the article, they are slowed and eventually stopped by the mass of the article. This limits the thickness of articles which can be effectively irradiated by electron beams.




X-rays have been used to irradiate articles. X-rays are advantageous in that they have no mass. The x-rays are in the form of electromagnetic energy which penetrates the articles to be sterilized. Since the x-rays have no mass, they are effective in irradiating articles with increased thicknesses. These significant thicknesses are considerably greater than the thicknesses of the articles which can be irradiated by other forms of energy such as electron beams.




There is one disadvantage, among others, in the use of x-rays to irradiate an article. This results from the fact that a considerable amount of energy remains in the x-rays after the x-rays have passed through the article. The energy remaining in the x-rays after the passage of the x-rays through the article is wasted because it has not been used for any useful purpose. Co-pending U.S. patent application Ser. No. 09/753,287 filed by applicants on Dec. 29, 2000 for a System for, and Method of, Irradiating Articles With X-Ray Beam and assigned of record to the assignee of record of this application discloses and claims a system for utilizing substantially all of the energy from the x-rays to irradiate articles.




There is another disadvantage in the use of x-rays to irradiate articles. The x-rays are generally produced by directing electrons to a converter which converts the electrons to x-rays. However, instead of constituting a focused beam as in the case of the electrons, the x-rays travel in different directions from the converter. A significant percentage of the x-rays move past the articles being irradiated without passing into the articles. This results in an inefficiency in the operation of the system since these x-rays do not provide any irradiation of the articles.




The processing inefficiency becomes particularly pronounced when the system is used with articles of different sizes. When the articles are relatively small, an increased amount of the radiation from the source moves past the articles without passing into the articles. When the articles are relatively large, not all of the volume in the articles receives a sufficient amount of x-rays from the source to become properly sterilized.




BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION




This invention provides a system for, and method of, passing radiation to an article so that an increase percentage of the x-rays passes into the article and the article becomes properly processed by the radiation. The system and method of this invention accomplish this by varying the distance between the position of generating the radiation and the position of individual articles, this variation being dependent upon changes in dimensions of the articles relative to the dimensions of other articles. In one preferred embodiment, the radiation source is displaced toward or away from the articles by a distance dependent upon the changes in the dimensions of the individual articles relative to the dimensions of the other articles.




In another preferred embodiment, the articles are moved on conveyors toward or away from the radiation source by a distance dependent upon the changes in the dimension of the individual articles relative to the dimensions of the other articles. In a third preferred embodiment, the individual articles are moved on the conveyor in a direction to vary the distance between the articles and the source of radiation.




Instead of processing a single article at any one time, the system may simultaneously process a plurality of articles which are disposed in a batch or in a stacked relationship.




In the preferred embodiments of the invention articles move on a conveyor mechanism in a first direction past a radiation source for a processing of the articles by radiation (e.g. gamma rays, electron beam or x-rays). The radiation moves in a second direction substantially perpendicular to the direction of movement of the conveyor. However, the radiation often has a component of movement in a direction perpendicular to the second direction. In effect, the radiation is scattered as a result of this perpendicular component of movement. Some radiation may move in the transverse direction past the articles without irradiating the articles. The distance between the radiation source and the articles on the conveyor mechanism may be adjusted to maximize the movement of the radiation to position in the article and to minimize the amount of the radiation which does not pass into the articles.




The adjustment may be made by (1) adjusting the position of the radiation source in a particular direction constituting the direction of the radiation source or (2) actuating an individual one of a plurality of conveyors for moving the articles past the radiation source, each conveyor being separated from the radiation by a distance different from the distance of the other conveyors from the radiation source, or (3) repositioning the articles on the conveyor in the particular direction. The distance between the radiation source and the conveyor mechanism may be varied dependent upon the variations in the dimension of the articles in a direction substantially perpendicular to (a) the direction of the radiation source and (b) the path of movement of the articles on the conveyor mechanism. Instead of irradiating a single article at any one time, the system may simultaneously irradiate a batch or stack of articles of the same or different sizes. It should be appreciated that the radiation source may be considered to include a converter for converting an electron beam to x-rays.











BRIEF DESCRIPTION OF THE DRAWINGS





FIGS. 1A and 1B

are schematic elevational views showing in

FIG. 1A

how radiation (e.g. x-rays) moves toward an article of small dimensions on a conveyor without passing through the article and showing in

FIG. 1B

how x-rays fail to irradiate all of the volume in an article of large dimensions on the conveyor;





FIGS. 2A

,


2


B and


2


C are schematic perspective views showing how the position of a radiation source (e.g. x-rays) is adjusted to provide for the passage of the x-rays to every position in articles of different dimensions and to prevent little, if any, of the x-rays from moving past the articles without moving into the articles;





FIG. 3

is a schematic block diagram of electrical circuitry for processing signals produced by the system of

FIGS. 2A-2C

to position the x-ray source in

FIGS. 2A-2C

from the article in the conveyor by a distance dependent upon changes in the different dimensions of the articles;





FIG. 4

is a schematic perspective view showing how articles of different dimensions are transported by individual ones of a plurality of conveyors, each displaced at a different distance from the radiation source (e.g. x-rays) than the others, to provide for the passage of the x-rays to every position in the articles of the different dimensions and to prevent little, if any, of the x-rays from moving past the articles without passing into the articles;





FIG. 5

is a schematic plan view showing how articles of different dimensions are moved on a single conveyor in a direction corresponding to the direction of the radiation source (e.g. x-rays) to provide for the passage of the x-rays to every position in the articles of the different dimensions and to prevent little, if any, of the x-rays from moving past the articles without passing into the articles; and





FIG. 6

is a perspective view schematically illustrating how a batch or stack may be formed by a plurality of articles of the same or different dimensions to provide for a simultaneous irradiation of the articles in the batch or stack by the system constituting the preferred embodiments of this invention.











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION




Systems are now being adopted for irradiating various types of articles including food products by radiating the articles. When the food products are relatively thin in the direction of the flow of the radiating energy, electron beams are now being used. The electron beams have a special utility when the articles being irradiated have a thickness within particular limits. For example, electron beams are used to irradiate flat hamburger patties weighing one quarter of a pound (¼ lb.) or one half of a pound (½ lb.) The electron beams are particularly effective when the articles are irradiated from opposite sides of the articles.




Electron beams are generally not effective in irradiating articles that are too thick. This results from the fact that the electron beams have mass. This mass causes the electrons to decelerate as they pass through the articles being irradiated. Thus, the interior of the articles does not receive a dose sufficient to kill bacteria. This is true even when the electron beams enter into the article from two (2) opposite sides of the article.




X-rays are often used to irradiate articles having a thickness greater than what is effective for electrons. X-rays are advantageous under such circumstances because they constitute electromagnetic energy which does not have any mass. A considerable disadvantage is that a considerable amount of the x-ray energy is not utilized in irradiating articles when the thickness of the articles is (a) above the range where the articles can be sterilized by electron beams (b) but below the range where the full intensity of the radiation from the x-rays can be efficiently utilized in irradiating the articles.




In U.S. patent application Ser. No. 09/753,287 filed by applicants on Dec. 29, 2000, for a System For, And Method of, Irradiating Articles With X-Ray Beam and assigned of record to the assignee of record of this application, a system and method are disclosed for providing for an efficient use of the full intensity of x-rays in processing the articles initially to the full intensity of the x-ray radiation from an accelerator and subsequently to the reduced intensity remaining in the x-rays after the initial radiation of the articles by the x-rays. The initial and subsequent radiation are provided in a way so that the number of articles radiated per unit of time is not reduced relative to the number of units which are radiated per unit of time when only the initial radiations are provided.




There is another disadvantage when x-rays are used to process articles. This may be seen from the schematic representations in

FIGS. 1A and 1B

. In

FIG. 1A

, a radiation source generally indicated at


10


produces a beam of electrons and impinges the electrons in the beam on a converter


12


(e.g. brehmstahling) made from a suitable material such as tungsten. The converter


12


converts the electrons to x-rays. This is well known in the art.




As will be seen, when the accelerator


10


has the position shown in

FIG. 1A

, some of the x-rays pass to an article


16




a


of a relatively small height on a conveyor


18


in a direction corresponding to the direction of the electron beam. This is indicated at


20


in

FIGS. 1A and 1B

. This direction is substantially perpendicular to the direction in which the conveyor


18


moves the article


16


past the electron beam from the accelerator


12


, this direction being perpendicular to the plane of the paper. These x-rays pass through the article


16




a


and irradiate the article. However, some of the x-rays are scattered, as indicated at


21


. The scattered x-rays move past the article


16




a


without passing into the article. These x-rays


21


have no effect in irradiating the article


16




a


. This is inefficient.




When an article has a relatively large height as shown in FIG.


1


B and the converter


12


is the same distance from the article as the distance shown in

FIG. 1A

, the x-rays pass to the article but fail to irradiate all of the positions of the article. This is indicated at


23


in FIG.


1


B. This is undesirable since not all of the harmful bacteria in the article may be killed. The harmful bacteria may then multiply in the article


16


and injure or kill individuals when the article is a food item and the individuals eat the food item.




Although the preferred embodiments are described with particular reference to x-rays, it should be appreciated that different types of radiation (e.g. gamma rays and electron beams) can be used without departing from the scope of the invention. Furthermore, although the articles being sterilized may be generally referred to as food products, it will be appreciated that other types of articles (e.g. drugs, medical instruments and medical implements) may be irradiated without departing from the scope of the invention. Furthermore, the articles may be irradiated to provide disinfestation, sprout inhibition, shelf life extension and modification of properties of materials without departing from the scope of the invention.




As an initial step, the accelerator


10


may be centered so that the x-rays


20


traveling directly to the article


16


are centered relative to the converter


12


. This will provide for the scattered x-rays


21


to pass on a balanced basis to positions into the article at positions above and below the positions where the directed x-rays pass into the articles. It will be appreciated that the radiation source


10


does not have to be centered relative to the converter


12


to accomplish the purposes of this invention.





FIG. 2A

schematically shows the paths of different x-rays when an article


16




a


on the conveyor


18


has a relatively small height and the converter


12


is an optimal distance from the article. The height of the article


16




a


is the direction substantially perpendicular to the direction of the electron beam from the accelerator


10


and substantially perpendicular to the path of movement of the article


16




a


on the conveyor


18


. It is indicated by an external wall


22




a


. As will be seen in

FIG. 2A

, substantially all of the x-rays including the directed x-rays


20


and the scattered x-rays


21


pass into the article


16




a


. Little, if any, of the x-rays


21


move past the article


16




a


without passing into the article. Furthermore, the x-rays


20


and


21


irradiate all of the positions in the article


16




a.






When an article


16




b


is moderately large as shown in

FIG. 2B

, at least with respect to the external wall


22




b


facing the converter


12


, the distance between the wall


22




b


of the article


16




b


and the converter


12


is increased. At an optimal distance, substantially all of the x-rays including the scattered x-rays


21


pass into the article


16




b


. Little, if any, of the x-rays


21


move past the article


16




b


without passing into the article. Furthermore, the x-rays


20


and


21


irradiate all of the positions in the article


16




b.






When an article


16




c


is relatively large as shown in

FIG. 2C

, at least with respect to the external wall


22




c


facing the converter


12


, the distance between the wall


22




c


of the article and the converter


12


is further increased. At an optimal distance, substantially all of the x-rays including the scattered x-rays


21


pass into the article


16




c


. Little, if any, of the x-rays move past the article


16




c


without passing into the article. Furthermore, the x-rays


20


and


21


irradiate all of the positions in the article


16


.




This invention provides different preferred embodiments of a system for positioning the article


16


relative to the converter


12


, or positioning the converter relative to the article, so that all of the positions in the article are properly processed and so that little, if any, x-ray energy moves past the article without passing into the article. In the embodiment shown in

FIGS. 2A-2C

, the converter


12


is provided with different positions depending upon the dimension of the wall


22


in the article


16


. For example, when the dimension of the wall


22




a


in the article


16




a


is relatively small as shown in

FIG. 2A

, the converter


12


is positioned relatively close to the article. When the dimension of the wall


22




b


in the article


16




b


is moderate, the converter


12


is disposed at a moderate distance from the article as shown in FIG.


2


B. When the dimension of the wall


22




c


in the article


16




c


is relatively large, the converter is at a relatively great distance from the article as shown in FIG.


2


C. In this way, the x-rays pass into all of the positions of the article


16


and the x-rays do not move past the articles without passing into the articles.




In the embodiments shown in

FIGS. 2A-2C

, a system generally indicated at


30


is provided for moving the converter


12


on an axis corresponding to the axis of the accelerator


10


. The movement of the converter


12


is provided on a track


32


as by a motor


34


in a direction relative to the face


22


of the article


16


so that all of the positions in of the article


14


are irradiated by the x-rays and so that little, if any, of the x-rays is lost by moving past the article


16


without passing into the article. The track


32


may be disposed in a direction corresponding to the direction of the electron beam in the accelerator


10


.




For example, if the x-rays move past the article


16


without passing into the article, the converter


12


is moved in a direction to decrease the distance between the converter and the article until substantially all of the x-rays pass into the article. On the other hand, when the face


22


of the article


16


is relatively large, the x-rays may not be able to irradiate all of the positions in the article


16


. The converter


12


is accordingly moved in a direction away from the article


16


so that substantially all of the x-rays, and particularly the scattered x-rays


21


, will be able to pass into the article and irradiate all of the different positions in the article and so that little, if any, of the x-rays will move past the article


16


without passing into the article. The converter


12


and the face


22


of the article


16


are preferably substantially parallel to each other.




The relative dimensions of the face


22


of the articles


16


may be determined by a detector


36


in a manner well known in the art. For example, the detector


36


my be optical, mechanical or electrical. The detector


36


may be movable by a motor


37


in opposite vertical directions indicated by arrows


38


so that the detector can determine the top of the article


16


and provide signals indicating this determination. The signals from the detector


36


are introduced to a processor such as a microprocessor


39


which produces instructions to the motor


34


to drive the converter


12


on the track


32


.





FIG. 4

schematically illustrates a second embodiment, generally indicated at


40


, of the invention. In this embodiment, the article


16


is moved toward or away from the converter


12


dependent upon the signals provided by the detector


36


to indicate the dimensions of the face


22


of the article. The article


16


may be moved in a direction corresponding to the direction of the accelerator


10


by disposing the article


16


on a selected one of a plurality of conveyors


42




a


,


42




b


and


42




c


, each of which is constructed to transport the article


16


past the converter


12


in a direction substantially perpendicular to the converter. The individual one of the conveyers


42




a


,


42




b


and


42




c


selected to transport the articles


20


at any instant is dependent upon the dimensions of the face


22


of the article


16


, as indicated by the signals from the detector


36


. Although three (3) conveyors


42




a


,


42




b


and


42




c


are shown in

FIG. 3

, it will be appreciated that any number of different conveyors can be provided.




It will be appreciated that the conveyors


42


,


42




b


and


42




c


may diverge from a common conveyor


44


which is disposed at a position before the position at which the articles are irradiated by the accelerator


10


. A microprocessor


46


responsive to the signals from the detector


36


controls the particular one of the conveyors


42




a


,


42




b


and


42




c


that receives each individual one of the articles.




The microprocessor


46


controls the actuation of gates


48




a


and


48




b


which are respectively pivotable at fulcrum positions


49




a


and


49




b


. When the gates


48




a


and


48




b


have the positions shown in

FIG. 4

, the articles


16




a


move past the accelerator


10


on the conveyor


42




b


. When the gate


48




a


is pivoted in a clockwise direction so that it extends across the width of the conveyor


42




b


, the conveyor


42




b


is blocked and the conveyor


42




a


is opened so that the articles


16




b


move on the conveyor


42




a


past the accelerator


10


. Similarly, when the gate


48




b


is pivoted in a counterclockwise direction so that it extends across the width of the conveyor


42




b


, the conveyor


42




b


is blocked and the conveyor


42




c


is opened so that the articles


16




c


move on the conveyor


42




c


past the accelerator


10


.




As shown schematically in

FIG. 3

, the conveyor


42




a


is constructed to receive articles


16




a


having the dimensions of the first face


22




a


in FIG.


1


A and the conveyor


42




b


is constructed to receive the articles


16




b


having the dimensions of the second face


22




b


. Since the face


22




a


of the article


16




a


is smaller than the face


22




b


of the article


16




b


, the conveyor


42




a


disposes the face


22




a


of the article


16




a


closer to the converter


12


than the conveyor


42




b


disposes the face


22




b


of the article


16




b


. Similarly, the conveyor


42




b


disposes the face


22




b


of the article


16




b


closer to the converter


12


than the conveyor


42




c


disposes the face


22




c


of the article


16




c


. The reason is that the face


22




b


of the article


16




b


is smaller than the face


22




c


of the article


16




c


. The articles


16




a


,


16




b


and


16




c


are schematically illustrated in FIG.


4


.




Instead of providing the detector


36


to determine the dimensions of the article


16


, the dimensions of the article


16


may be programmed into the microprocessor


46


. Thus, as each article


16


moves past the radiation source


10


, the microprocessor programs the system to adjust the distance between the radiation source


10


and the article


16


.





FIG. 5

illustrates another preferred embodiment of the invention. In this embodiment, the articles


16


are disposed on a single conveyor


16


. The conveyor


50


is provided with rollers such as rollers


52


and


54


. The rollers


52


are disposed in a transverse relationship to the direction


56


of movement of the conveyor so that the rollers provide the article


16


with a component of movement in the direction


56


and a component of movement toward the radiation source


10


. The rollers


54


are disposed in a transverse relationship to the direction


56


of movement of the conveyor


50


so that the rollers provide the article


16


with a component of movement in the direction


50


and a component of movement of the article


10


away from the radiation source


10


.




When it is determined as by a microprocessor


58


that the article


16


has to be moved toward the radiation source


10


, the microprocessor causes the rollers


52


to be activated for a period of time dependent upon the distance that the article


16


has to be moved toward the left in FIG.


5


. This causes the article


16


to have a position indicated in broken lines at


60


in

FIG. 5

as the article moves past the radiation source


10


.




When it is determined as by the microprocessor


58


that the article


16


has to be moved away from the radiation source


10


, the microprocessor causes the rollers


54


to be activated for a period of time dependent upon the distance that the article


16


has to be moved toward the right in FIG.


5


. This causes the article


16


to have a position indicated in broken lines at


62


in

FIG. 5

as the article moves past the radiation source


10


.





FIG. 6

illustrates how the system shown in

FIGS. 2-5

may process a plurality of articles simultaneously instead of processing a single article at a time as described above. As shown in

FIG. 6

, a batch or stack of articles is generally indicated at


70


. The batch or stack


70


may be formed from a plurality of articles


72


,


74


,


76


, etc., all of which may be of the same dimensions or some of which may have different dimensions. The system shown in

FIGS. 2-5

determine, or receive information relative to, the batch or stack


70


to determine the positioning of the batch or stack


70


relative to the radiation source


10


. It will be accordingly be seen that the term “articles” as used in the claims is intended to include individual articles such as shown in

FIGS. 2-5

and batches or stacks of articles of the same or different dimensions such as shown in FIG.


6


.




Although this invention has been disclosed and illustrated with reference to particular preferred embodiments, the principles involved are susceptible for use in numerous other embodiments which will be apparent to persons of ordinary skill in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.




Although x-rays may be sometimes specifically discussed in the specification as the source of radiation in different preferred embodiments of the invention, such forms of electron magnetic energy as electron beams, x-rays and gamma rays may be considered as equivalent forms of radiation from the standpoint of the language of the claims.



Claims
  • 1. In combination for irradiating articles where individual articles have changes in dimensions relative to the dimensions of other articles, including,a radiation source for providing radiation, a device for indicating the changes in the dimensions of the individual articles and for providing signals indicative of such dimensions, dependent upon the signals from the device, a drive member responsive to the signals from the device for displacing at least one of the radiation source and the articles in a particular direction, dependent upon the signals from the device, defining the distance between the radiation source and the articles, and a conveyor for moving the articles past the radiation source to obtain an irradiation of the articles by the radiation from the source.
  • 2. In a combination as set forth in claim 1 whereinthe radiation source provides radiation having particular characteristics in a particular direction transverse to the direction defining the distance between the radiation source and the articles and wherein the individual articles have changes in dimensions in the particular direction relative to the dimensions of the other articles and wherein the device indicates the dimensions in the particular direction for the individual ones of the articles and wherein dependent upon the signals from the device, the drive member displaces the at least one of the radiation source and the articles in the particular direction.
  • 3. In a combination as set forth in claim 1 whereinthe radiation source constitutes the at least one of the radiation source and the articles.
  • 4. In a combination as set forth in claim 1 whereineach of the articles constitutes the at least one of the radiation source and the articles.
  • 5. In a combination as set forth in claim 1 whereinthe radiation from the source emanates from the source in directions transverse to the particular direction and wherein the at least one of the radiation source and the articles is displaceable in the particular direction dependent upon the changes in the dimension of the individual ones of the articles relative to the dimensions of the other articles in a direction substantially perpendicular to the particular direction.
  • 6. In a combination as set forth in claim 5 whereinthe at least one of the radiation source and the individual articles is displaced toward the other one of the radiation source and the individual articles dependent upon decreases in the dimension of the individual articles in the substantially perpendicular direction relative to the dimension of the other articles and wherein the at least one of the radiation source and the individual articles is displaced away from the other one of the radiation source and the individual articles dependent upon increases in the dimension of the individual articles in the substantially perpendicular direction relative to the dimensions of the other articles.
  • 7. In a combination as set forth in claim 1 whereina plurality of conveyors are provided for moving the articles past the radiation source for an irradiation of the articles by the x-rays from the radiation source and wherein each of the conveyors is displaced from the radiation source by a different distance than the distance of the displacement of the other ones of the conveyors from the radiation source and wherein a microprocessor selects a particular one of the conveyors dependent upon the changes in dimensions of the individual articles in the perpendicular direction relative to the dimensions of the other articles.
  • 8. In a combination as set forth in claim 7 whereinthe conveyor selected at each instant to displace the individual articles from the radiation source is displaced from the individual articles by a distance related to the changes in the dimensions of the individual articles in the perpendicular direction relative to the dimensions of the other articles.
  • 9. In a combination as set forth in claim 1 whereina single conveyor is provided and wherein the articles are displaced on the conveyor toward or away from the radiation source by a distance dependent upon the changes in the dimensions of the individual one of the articles relative to the dimensions of the other articles.
  • 10. In combination for irradiating individual articles where the individual articles have changes in dimensions relative to other articles, includinga radiation source disposed in a particular direction to emit radiation in the particular direction with some of the radiation having a directional component perpendicular to the particular direction, a plurality of conveyor paths each disposed to convey the articles past the radiation source in a direction substantially perpendicular to the particular direction of the emitted radiation at a distance from the radiation source different from the distance of the other conveyor paths from the radiation source, a device for indicating the changes in dimensions of the individual articles in the perpendicular direction relative to the dimensions of the other articles, and apparatus responsive to the determination by the device of the changes in the dimensions of the individual articles relative to the dimensions of the other articles in the perpendicular direction for providing for an activation of an individual one of the conveyor paths dependent upon the indication by the device to obtain a movement of the individual articles on the individual one of the conveyor paths past the radiation source for an irradiation of the individual articles on the conveyor path by the radiation source.
  • 11. In a combination as set forth in claim 10 whereinthe activating apparatus provides for an activation of the individual one of the conveyors displaced from the radiation source by a distance related to the changes in the dimensions of the individual articles relative to the dimensions of the other articles in the perpendicular direction.
  • 12. In a combination as set forth in claim 10 whereinthe activating apparatus provides for an activation of the individual one of the conveyor paths, which individual ones of the conveyor paths provide for an optimal emanation of the radiation from the source to the individual articles dependent upon the indication by the device of the changes in the dimensions of the individual articles in the particular direction relative to the dimensions of the other articles.
  • 13. In a combination as set forth in claim 10 whereinthe activating apparatus provides for an activation of an individual one of the conveyor paths, which individual one of the conveyor paths provides for an irradiation of each position in the individual articles by the radiation from the source and for a minimal passage of the radiation from the source past the individual articles without passing into the individual articles.
  • 14. In combination for irradiating individual articles having changes in dimensionsrelative to the dimensions of other articles, including a source of radiation, a conveyor mechanism for moving the individual articles past the radiation from the source to obtain an irradiation of the individual articles on the conveyor mechanism, and a positioning mechanism operatively coupled to at least a particular one of the conveyor mechanism and the radiation source for varying the dimensional relationship between the radiation source and the individual articles on the conveyor mechanism dependent upon the dimensions of the individual articles relative to the dimensions of the other articles.
  • 15. In a combination as set forth in claims 14 whereinthe radiation source is moved in a direction toward and away from the conveyor mechanism dependent upon the dimensions of the individual articles on the conveyor mechanism relative to the dimensions of the other articles.
  • 16. In a combination as set forth in claim 14 whereinthe disposition of the conveyor mechanism relative to the radiation source is varied dependent upon the dimensions of the individual articles on the conveyor mechanism relative to the dimensions of the other articles.
  • 17. In combination as set forth in claim 14 whereina device provides signals representing the changes in the dimensions of the individual articles on the conveyor mechanism relative to the dimensions of the other articles and wherein the positioning mechanism is responsive to the signals from the device for varying the distance between the radiation source and the individual articles on the conveyor mechanism in the direction toward and away from the conveyor mechanism.
  • 18. In a combination as set forth in claim 15 whereinthe positioning mechanism is responsive to the signals from the device for displacing the radiation source in a direction to vary the distance between the radiation source and the individual articles on the conveyor mechanism.
  • 19. In a combination as set forth in claim 15 whereinthe positioning mechanism is responsive to the signals from the device for displacing the conveyor mechanism in a direction to vary the distance between the radiation source and the individual articles on the conveyor mechanism.
  • 20. In a combination as set forth in claim 15 whereina single conveyor mechanism is provided and wherein the positioning mechanism is responsive to the signals from the device for displacing the individual articles on the conveyor mechanism in a direction to vary the distance between the radiation source and the articles on the conveyor mechanism.
  • 21. A method of irradiating individual articles where the individual articles have changes in dimensions relative to the dimensions of other articles, including the steps of:providing a source of radiation, providing a conveyor mechanism for conveying the articles past the radiation source providing for the direction of the radiation to the articles on the conveyor mechanism during the conveyance of the articles by the conveyor mechanism, determining changes in the dimensions of the individual articles relative to the dimensions of other articles, dependent upon the determined changes in the dimensions of the individual articles relative to the dimensions of the other articles, and adjusting the relative distance between the radiation source and the articles on the conveyor mechanism.
  • 22. A method as set forth in claim 21 whereindependent upon the changes in the dimensions of the individual articles on the conveyor mechanism relative to the dimensions of the other articles, the step of adjusting involves an adjustment in the position of the radiation source in a direction to vary the distance between the radiation source and the individual articles on the conveyor mechanism.
  • 23. A method as set forth in claim 21 whereindependent upon the changes in the dimensions of the individual articles on the conveyor mechanism relative to the dimensions of the other articles, the step of adjusting involves a displacement of the conveyor mechanism to vary the distance between the radiation source and the articles on the conveyor mechanism.
  • 24. A method as set forth in claim 21 whereinthe step of adjusting involves a selection of an individual one of a plurality of conveyor mechanisms each displaced from the radiation source by a particular distance different from the displacement of the other ones of the conveyor mechanisms from the radiation source and wherein the selected one of the conveyor mechanisms conveys the individual articles past the device.
  • 25. A method as set forth in claim 21 whereina single conveyor mechanism is provided and wherein the step of adjusting involves a movement of the individual articles on the conveyor mechanism to vary the distance between the radiation source and the individual articles on the conveyor mechanism.
  • 26. A method as set forth in claim 21 whereindependent upon the indications of the changes in the dimensions of the individual articles relative to the dimensions of the other articles, the step of adjusting includes the step of indicating the dimensions of the individual articles on the conveyor mechanism in a direction transverse to the distance between the radiation source and the articles on the conveyor mechanism and includes the step of varying the distance between the radiation source and the individual articles on the conveyor mechanism.
  • 27. A method as set forth in claim 21 whereinthe radiation source includes a source of electrons and a converter responsive to the electrons for producing x-rays and wherein the step of adjusting includes the step of adjusting the position of the converter to vary the distance between the converter and the individual articles on the conveyor mechanism.
  • 28. A method as set forth in claim 25 whereinthe step of adjusting includes the step of adjusting the position of the individual articles on the conveyor mechanism in a direction to vary the distance between the radiation source and the conveyor mechanism.
  • 29. A method as set forth in claim 23 whereinthe conveyor mechanism includes a plurality of conveyors each displaced from the radiation source by a distance different from the displacement of the other ones of the conveyors from the radiation source and wherein each of the conveyors is individually operative to move the articles on the conveyor past the radiation source for an irradiation of the articles by the radiation source and wherein the step of varying includes the step of activating an individual one of the conveyor mechanisms at each instant to vary the distance between the converter and the articles dependent upon the activation of the individual one of the conveyors.
  • 30. A method of irradiating individual articles with x-rays where the individual articles have changes in dimensions for receiving the radiation relative to the dimensions of other articles, including the steps of:providing a conveyor mechanism for conveying the articles, providing radiation and directing the radiation to the individual articles on the conveyor mechanism, determining changes in the dimensions of the face of individual articles closest to the radiation source, and providing for changes in the distance between the individual articles and the conveyor mechanism in accordance with the changes determined in the dimensions of the face of individual articles closest to the radiation source.
  • 31. A method as set forth in claim 30 whereinan electron beam is directed toward the face of the individual articles on the conveyor mechanism as the individual articles move on the conveyor mechanism past the radiation and wherein the electrons in the beam are converted to x-rays and wherein the dimensions of the x-rays are varied dependent upon the changes in the dimensions of the articles faces of the articles closest to the radiation source relative to the dimensions of the other articles.
  • 32. A method as set forth in claim 30 whereinan electron beam is formed from electrons and is directed toward the face of the individual articles on the conveyor mechanism as the individual articles move on the conveyor mechanism past the radiation and wherein the x-rays are produced by introducing the electrons in the electron beam to a converter and wherein dependent upon the changes in the dimensions of the face of the articles, the position of the converter is varied in the same direction as the electron beam to change the distance between the converter and the face closest on the individual articles to the converter.
  • 33. A method as set forth in claim 31 whereinthe electron beam is directed toward the face of the individual articles on the conveyor as the individual articles move on the conveyor past the electron beam and wherein the x-rays are produced by introducing the electrons in the electron beam to a converter to x-rays and wherein the disposition of the individual articles on the conveyor during the movement of the individual articles past the converter is varied in the same direction as the electron beam to change the distance between the converter and the face of the individual articles dependent upon the changes in the dimensions of the face receiving the radiation in the individual articles.
  • 34. A method as set forth in claim 33 whereinthe conveyor constitutes a single conveyor.
  • 35. A method as set forth in claim 33 whereinthe conveyor constitutes a plurality of conveyor mechanisms each displaced by a different distance from the radiation source and wherein an individual one of the conveyor mechanisms is activated at each instant dependent upon the changes in the dimensions of the face receiving the radiation in the articles.
  • 36. A method as set forth in claim 35 whereinthe dimensions of the face of the individual articles are indicated and wherein dependent upon the changes in the dimensions of the face of the individual articles relative to the dimensions of the other articles, the change is made in the position of the converter to provide for a processing of each position in the articles by the x-rays and to prevent the x-rays from moving past the face of the articles without passing into the articles.
  • 37. A method of irradiating individual articles where the individual articles have faces with changes in dimensions relative to the dimensions of other articles, including the steps of:producing x-rays, conveying the individual articles past the x-rays for a processing of the individual articles by the x-rays, and determining changes in the dimensions of the faces of the individual articles, dependent upon the determined changes in the dimensions of the faces of the individual articles, and providing for an adjustment in the space occupied by the x-rays at the faces of the individual articles closest to the production of the x-rays to obtain a processing relative to the dimensions of the faces of the other articles.
  • 38. A method as set forth in claim 37, including the steps of:indicating the changes in the dimensions of the faces of the individual articles relative to the dimensions of the faces of the other articles, and adjusting the space occupied by the x-rays at the face of the articles closest to the production of the x-rays, such adjustments being dependent upon the changes in the dimensions of the face of the individual articles relative to the dimensions of the faces of the other articles.
  • 39. A method as set forth in claim 37, including the step of:adjusting the distance between the production of the x-rays and the disposition of the individual articles in the conveyance of the individual articles past the x-rays, such adjustment being dependent upon changes in the dimensions of the face of the individual articles relative to the dimensions of the face of the other articles.
  • 40. A method as set forth in claim 37 whereinthe adjustment is made by adjusting the disposition of the articles in the conveyance of the articles past the x-rays.
  • 41. A method as set forth in claim 37 whereinthe distance adjustment is made by adjusting the position where the x-rays are produced.
  • 42. A method as set forth in claim 37 whereinthe articles are moved on a single conveyor and wherein dependent upon the changes in the dimensions on the face of the individual articles receiving the x-rays relative to the dimensions of the faces of the other articles, the articles are adjusted in position on the single conveyor in a direction corresponding to the direction of the x-rays.
US Referenced Citations (3)
Number Name Date Kind
5838760 Moses Nov 1998 A
6429444 Korenev et al. Aug 2002 B1
6504898 Kotler Jan 2003 B1