GB2367797A

GB2367797A - Folding a conveyor of an x-ray apparatus

Info

Publication number: GB2367797A
Application number: GB0121307A
Authority: GB
Inventors: Masayuki Uno; Takeshi Ikuta; Atsushi Takahashi
Original assignee: Ishida Co Ltd
Current assignee: Ishida Co Ltd
Priority date: 2000-09-08
Filing date: 2001-09-03
Publication date: 2002-04-17
Anticipated expiration: 2021-09-03
Also published as: GB0121307D0; CN101078695A; JP2002082071A; JP3526263B2; CN101078695B; CN1343881A; GB2367797B; CN100360927C

Abstract

An x-ray detector 1 comprises a housing 15 and a conveyor 2 which extends beyond a length of the housing 15 , such as through aperture 11 in two opposite end walls of the housing 15. Within a belt of the conveyor 2 is featured a transverse shaft 25 which allows the conveyor 2 and belt to be folded, such as on a internal frame structure 21 between end pulleys 22,23, so that it might be passed through an opening 12, such as in a side wall of the housing 15, that it would not normally fit through in its extended state. This may permit easy removal of the conveyor 2 for cleaning of the conveyor and/or the interior of the housing 15. Also disclosed are two further proposed inventions directed at the nature of a engagement of between the conveyor 2 and a frame 5 which might hold it.

Description

X-ray Foreign Matter Detecting Apparatus

The present invention relates to an X-ray foreign matter detecting apparatus for detecting the presence or absence of foreign matter such as, for example, metallic and/or non-metallic particles in an article being inspected.

In this type of prior art X-ray foreign matter detecting apparatus, it has been a general practice to remove a transport belt from the apparatus and then to cleanse only the transport belt. This is not insufficient. In other words, when the articles are inspected to determine the presence or absence of foreign matter in each of the articles while the latter are transported successively by the transport conveyor, it is often observed that other than the transport belt, frames and rollers for the support of the transport belt are equally contaminated and, therefore, when it comes to cleansing the transport conveyor, it is desirable that the transport conveyor in its entirety is to be removed from the apparatus and then to be cleansed. Accordingly, it has been suggested in, for example, the Japanese Laid-open Patent Publication No. 9-250992, to use two transport conveyors arranged removably in series with each other within a conveyor housing so that the transport conveyors in their entirety can be removed from and inserted into the conveyor housing in a direction generally perpendicular to the direction of transport of the articles.

Where the two transport conveyors are employed, removal from and insertion of the transport conveyors can be achieved easily since the length of each conveyor is relatively small. However, it has been found that the presence of a gap between these two transport conveyors allows dust and rubbish to be piled up and that the apparatus as a whole tends to have a complicated internal structure. For this reason, it is desirable to use a single transport conveyor

while arrangement is made to enable the single transport conveyor to be selectively removed from and reset into the conveyor housing.

Where the single transport conveyor is to be employed, the transport conveyor must have a length that is greater than the corresponding length of the conveyor housing as measured in a direction conforming to the direction of transport of the articles, in order for the transport conveyor to be operatively linked front and rear stages of machinery in a transport line with respect to the direction of transport of the articles. Also, in order to enable the single transport conveyor to be selectively removed from and inserted into the conveyor housing, it is necessary not only for the conveyor housing to have openings defined therein in opposition to each other in front and rear walls of the conveyor housing with respect to the direction of transport of the articles so that respective end portions of the transport conveyor can extend outwardly of the conveyor housing through these openings, but also for the conveyor housing to have a takeout opening defined in one of opposite side walls thereof lying perpendicular to the front and rear walls thereof in communication with the respective openings in the front and rear walls so that the transport conveyor can be removed out of or reset in position inside the conveyor housing. For this reason, the conveyor housing will be a cantilever design in which the opening is supported only on the side wall opposite to the side wall having the takeout opening, resulting in reduction in strength.

In view of the foregoing, the present invention is intended to provide an X-ray foreign matter detecting apparatus wherein, even though the transport conveyor is employed of a length greater than the length of the conveyor housing as measured in the direction of transport, the opening defined in the conveyor housing and through which the transport conveyor extends is of a double-sided support structure so that the conveyor housing can have an increased strength and

wherein selective removal and insertion of the transport conveyor from and into the conveyor housing can be easily achieved.

In order to achieve the above described object of the present invention, the present invention in one aspect thereof provides an X-ray foreign matter detecting apparatus which includes a conveyor housing ; a transport conveyor removably accommodated within the conveyor housing for transporting articles successively across the conveyor housing. The transport conveyor includes a conveyor framework and having a length greater than a length of the conveyor housing as measured in a direction conforming to a direction of transport of the articles. A bending support shaft is provided so as to extend across the transport conveyor to thereby pivotally connect one end portion of the conveyor framework to a frame body forming the other portion of the conveyor framework.

When for the purpose of, for example, cleansing the transport conveyor, the transport conveyor in its entirety is to be removed out of the conveyor housing, the one end portion of the conveyor framework is bent about the bending support shaft relative to the frame body to thereby shorten the length of the transport conveyor to a value smaller than the length of the conveyor housing as measured in the transport direction. Since the transport conveyor is thus shortened, even though the transport conveyor is employed of a length in operation greater than the length of the conveyor housing as measured in the transport direction, the transport conveyor can be easily removed in its entirety out of the conveyor housing through a takeout opening defined in, for example, one of opposite side walls of the conveyor housing that confront to each other in a widthwise direction perpendicular to the direction of transport of the articles by the transport conveyor. Similarly, resetting of the transport conveyor once removed can easily be achieved with the transport conveyor held in a bend position. Also, since there is no need to open one side of each of the openings in the conveyor housing through which the transport conveyor protrudes

outwardly of the conveyor housing in order to enable to the transport conveyor to be removable laterally outwardly of the conveyor housing, the opening can have a double-sided support structure with the conveyor housing consequently increased in strength.

The present invention according to a second aspect thereof also provides an X-ray foreign matter detecting apparatus which includes a conveyor housing ; and a transport conveyor removably accommodated within the conveyor housing for transporting articles successively across the conveyor housing and including a conveyor framework and has a length greater than a length of the conveyor housing as measured in a direction conforming to a direction of transport of the articles. One end portion of the conveyor framework is slidably connected with the other portion of the conveyor framework such that the length of the transport conveyor can be shortened when such one end portion of the conveyor framework is slid inwardly of and relative to such other portion of the conveyor framework.

Even with this structure, since the length of the transport conveyor as measured in the transport direction can be reduced, as is the case with the X-ray foreign matter detecting apparatus according to the first aspect of the present invention, even though the transport conveyor is employed of a length in operation greater than the length of the conveyor housing as measured in the transport direction, the transport conveyor can be easily removed in its entirety out of the conveyor housing through a takeout opening defined in, for example, one of the opposite side walls of the conveyor housing that confront to each other in a widthwise direction perpendicular to the direction of transport of the articles by the transport conveyor. Similarly, resetting of the transport conveyor once removed can easily be achieved with the transport conveyor held in a bend position. Also, since there is no need to open one side of each of the openings in the conveyor housing through which the transport conveyor protrudes outwardly of the conveyor housing in order to enable to the transport conveyor to

be removable laterally outwardly of the conveyor housing, the opening can have a double-sided support structure with the conveyor housing consequently increased in strength.

In a preferred embodiment of the present invention, the conveyor framework of the transport conveyor is provided with a first engagement member, and the conveyor housing is provided with a first receiving member for receiving the first engagement member in a direction parallel to the direction of transport of the article to thereby restrict up and down displacement of the first engagement member in a direction generally perpendicular to the transport conveyor.

According to the use of the first engagement member in the conveyor framework in combination with the first receiving member in the conveyor housing is effective to facilitate removal and resetting of the transport conveyor relative to the conveyor housing through the first engagement member and the first receiving member. Also, when the transport conveyor is to be reset in position inside the conveyor housing, engagement of the first engagement member in the first receiving member is effective to allow the transport conveyor to run without undergoing an undesirable up and down displacement. As a result thereof, where the presence or absence of foreign matter in each of the articles being transported is to be detected by irradiating each of the articles on the transport conveyor from above and detecting the X-rays by means of an X-ray detector positioned below the transport conveyor and then by processing images of foreign matter, the accuracy with which the presence of foreign matter is detected by means of the image processing can be increased since undesirable up and down motion of the article being transported can be suppressed.

Also, in a preferred embodiment of the present invention, the conveyor framework of the transport conveyor is also provided with a second engagement member, and the conveyor housing is provided with a second receiving member for receiving the second engagement member in a downward

direction, or from, above to thereby restrict forward and rearward displacement of the second engagement member in the direction generally parallel to the transport conveyor.

According to this preferred embodiment, since through the first and second engagement members and the first and second receiving members the transport conveyor can be mounted in the conveyor housing and run without undergoing undesirable displacement not only in the forward and rearward direction, but also in up and down direction, the X-ray inspection of the articles can be successively performed accurately in a stable fashion. Also, at the time of removal of the transport conveyor out of the conveyor housing, for example, bending the transport conveyor about the bending support shaft results in disengagement of the first engagement member from the first receiving member, followed by lifting the second engagement member to disengage from the second receiving member. In this way, engagement of the transport conveyor relative to the conveyor housing can be released and, by shorting the overall length thereof to a value smaller than the length of the conveyor housing as measured in the transport direction, the transport conveyor can readily and easily be removed out of the conveyor housing through the takeout opening defined in the conveyor housing. Similarly, resetting of the transport conveyor into the conveyor housing can also be achieved easily.

In one preferred embodiment of the present invention, in addition to the use of the first engagement member and the first receiving member, the conveyor framework of the transport conveyor is provided with a third engagement member, and the conveyor housing is provided with a third receiving member for restricting up and down displacement of the first engagement member in a direction generally perpendicular to the transport conveyor, the third receiving member receiving the third engagement member in a direction parallel to, but in a direction counter to the direction in which the first receiving member receives the first engagement member.

According to this design, at two locations corresponding to the first and third engagement members and the first and third receiving members, up and down displacement of the transport conveyor is suppressed and, therefore, the accuracy of the X-ray inspection subjected to the articles being successively transported can be increased. Also, selective removal of and insertion of the transport conveyor from and into the conveyor housing are also easily achieved. By way of example, when the transport conveyor is desired to be removed out of the conveyor housing, shortening of the transport conveyor results in movement of the first and third engagement members from the first and third receiving members, respectively, in a direction counter to the direction in which the first and third engagement members are engaged respectively in the first and third receiving members, to thereby release the respective engagement between the first and third engagement members and the first and third receiving members and, accordingly, the transport conveyor can easily be removed out of the conveyor housing through the takeout opening defined in, for example, a side wall of the conveyor housing. Similarly, resetting of the transport conveyor into the conveyor housing can also be achieved easily.

In accordance with a third aspect of the present invention, there is also provided an X-ray foreign matter detecting apparatus which includes a conveyor housing; a transport conveyor removably accommodated within the conveyor housing for transporting articles successively across the conveyor housing, and including a conveyor framework and having a length greater than a length of the conveyor housing as measured in a direction conforming to a direction of transport of the articles; first and second engagement members provided in the conveyor framework of the transport conveyor ; and first and second receiving members provided in the conveyor housing for cooperating with the first and second engagement members, respectively. The first receiving member receives the first engagement member in a direction generally parallel to the direction of transport of the article to thereby restrict up and down

displacement of the first engagement member, whereas the second receiving member receives the first engagement member in a downward direction, or from above, to thereby restrict forward and rearward displacement of the second engagement member.

With this X-ray foreign matter detecting apparatus, through the first and second engagement members and the first and second receiving members the transport conveyor can be mounted in the conveyor housing and run without undergoing undesirable displacement not only in the forward and rearward direction, but also in up and down direction. Accordingly, particularly since up and down motion of the articles being transported can be suppressed, in the event that the articles being successively transported are inspected as to the presence or absence of foreign matter in each of the articles by irradiating each article from above with X-rays, detecting the X-rays with the X-ray detector positioned below the transport conveyor and finally processing a radioscopic image, since up and down motion of the articles being transported is suppressed, the accuracy of detection of the presence or absence of the foreign matter by means of the image processing can be increased.

Although the transport conveyor is not bendable, even though the transport conveyor is employed of a length greater than the length of the conveyor housing as measured in the direction of transport, selective removal and insertion of the transport conveyor out of and into the conveyor housing can also be performed easily. By way of example, at the time of removal of the transport conveyor out of the conveyor housing, pivoting the transport conveyor upwardly about the first engagement member to thereby disengage the second engagement member from the second receiving member, followed by movement of the transport conveyor horizontally to thereby disengage the first engagement member from the first receiving member results in a quick release of the engagement of the transport conveyor.

Thus, after the engagement of the transport conveyor has been released, either by causing one end portion of the transport conveyor to protrude a considerable distance outwardly from one of openings that are defined forwardly and rearwardly of the conveyor housing, respectively, for allowing respective portions of the transport conveyor to protrude outwardly of the conveyor housing, the transport conveyor is pulled outwardly through a takeout opening defined in, for example, one of opposite side walls of the conveyor housing, with the other end of the transport conveyor oriented outwardly therethrough, or by pulling the transport conveyor outwardly from one of openings that are defined forwardly and rearwardly of the conveyor housing, the transport conveyor can be easily removed out of the conveyor housing without being interfered by the front and rear stages of machinery. Similarly, resetting of the transport conveyor into the conveyor housing can be achieved easily.

Also, since there is no need to open one side of each of the openings in the conveyor housing through which the transport conveyor protrudes outwardly of the conveyor housing in order to enable to the transport conveyor to be removable laterally outwardly of the conveyor housing, the opening can have a double-sided support structure with the conveyor housing consequently increased in strength.

In one preferred embodiment of the present invention, the X-ray foreign matter detecting apparatus is provided with an X-ray emission source for emitting X-rays towards the transport conveyor from above; an X-ray detector for detecting, at a position below the transport conveyor, the X-rays which have been emitted from the X-ray emission source and have subsequently penetrated through an X-ray penetrating region of the transport conveyor ; and X-ray shielding members positioned forwardly and rearwardly of the X-ray penetrating region, respectively, with respect to the direction of transport of the articles, so as to extend in a direction widthwise of the transport conveyor for shielding the X-rays. With this structure, the X-rays emitted from the X-ray emission source

are detected by the X-ray detector after having passed through the X-ray penetrating region of the transport conveyor so that by these X-rays the presence or absence of foreign matter in each of the articles being successively transported can be inspected. At this time, the X-rays traveling from the X-ray emission source towards the X-ray detector and scattering rays are shielded by the X-ray shielding members and, accordingly, they do not leak from forward and rearward directions of the X-ray penetrating region to the outside of the conveyor housing with high emission shielding effect.

Preferably, the conveyor housing includes frame members positioned leftwards and rightwards of the direction of transport of the articles by the transport conveyors, respectively. This structure is effective in that portions of the conveyor housing adjacent openings defined therein for allowing the portions of the transport conveyor to protrude outwardly of the conveyor housing in forward and rearward directions, respectively, can have a double-sided support structure owing to the conveyor framework, resulting in increase of the strength of the conveyor housing itself.

In the accompanying drawings, like reference numerals are used to denote like parts throughout the several views, and: Fig. 1 is a perspective view of an X-ray foreign matter detecting apparatus according to a first preferred embodiment of the present invention; Fig. 2 is a side view of a transport conveyor employed in the detecting apparatus shown in Fig. 1; Fig. 3 is a top plan view of the transport conveyor shown in Fig. 2; Fig. 4 is a side view, on an enlarged scale, showing an important portion of the transport conveyor shown in Fig. 2; Fig. 5 is a top plan view showing an important portion of the transport conveyor shown in Fig. 2;

Fig. 6 is a side view showing a support structure for the transport conveyor shown in Fig. 1 ; Fig. 7 is a side view of the transport conveyor according to a second preferred embodiment of the present invention ; Fig. 8 is a side view showing the manner in which the transport conveyor according to a third preferred embodiment of the present invention is mounted; and Fig. 9 is a view similar to Fig. 8, showing the manner in which the transport conveyor of Fig. 8 is removed.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

Fig. 1 illustrates a schematic perspective view of an X-ray foreign matter detecting apparatus in its entirety according to a first preferred embodiment of the present invention. The illustrated detecting apparatus includes a conveyor housing 1 having a front wall 15a, a rear wall 15b opposite to the front wall 15a, a left wall 15c lying generally perpendicular to any one of

the front and rear walls 15a and 15b, a right wall 15d opposite to the left wall 15c and a top wall 15e. The detecting apparatus also includes a bendable transport conveyor 2 accommodated within the conveyor housing I and positioned at a location generally intermediate of the height of the conveyor housing 1, an X-ray emission source 3 accommodated within the conveyor housing 1 and positioned above the transport conveyor 2, and an X-ray detector 20 accommodated within the conveyor housing 1 and positioned below the transport conveyor 2 for detecting X-rays emitted from the X-ray emission source 3 and passed across an X-ray penetrating region 2a of the transport conveyor 2. X-rays emitted from the X-ray emission source 3 are, after having passed across the X-ray penetrating region 2a of the transport conveyor 2, detected by the X-ray detector 20, and the X-rays so traveling from the X-ray emission source 3 towards the X-ray detector

20 are utilized to perform an X-ray inspection of articles M being successively transported by the transport conveyor 2 to determine the presence or absence of foreign matter such as metallic and/or non-metallic particles in each of the articles M being inspected.

The transport conveyor 2 is utilized to transport the articles M in a forward direction shown by the arrow F and has a length greater than the length of the conveyor housing 1 as represented by the distance between the front and rear walls 15a and 15b thereof. On the other hand, the front and rear walls 15a and 15b of the conveyor housing 1 have respective conveyor openings 11 defined therein in alignment with each other. Accordingly, when the transport conveyor 2 is positioned inside the conveyor housing, opposite end portions of the transport conveyor 2 protrude outwardly from the front and rear conveyor openings 11. As will become clear from the subsequent description, this transport conveyor 2 is removable from the conveyor housing 1 for facilitating, for example, cleansing of the transport conveyor 2 and, for this purpose, the left wall 15c of the conveyor housing 1 has a takeout opening 12 defined therein through which the transport conveyor 2 as a whole can be removed out of the conveyor housing 1. For avoiding leakage of X-rays outwardly from the takeout opening 12, an X-ray shielding door 13 is hingedly connected to the conveyor housing 1 for selectively opening and closing the takeout opening 12.

More specifically, the conveyor housing 1 includes four upright frames 14 connecting the walls 15a to 15e together to render the conveyor housing 1 to represent a generally rectangular box-like configuration. In this conveyor housing 1 of the structure described hereinabove, since the takeout opening 12 is located laterally of the transport conveyor 2, respective portions of the front and rear walls 15a and 15b and the adjacent upright frames 14 are left on left and right sides of the associated conveyor openings 11, and front and rear portions of the left wall 15c are left on respective sides of the takeout opening 12, so that opposite sides of each of the conveyor openings 11 can be supported to

represent a double-sided support structure, the conveyor housing 1 can have an increased strength.

This conveyor housing 1 also accommodates a first display 16 for displaying operating modes during inspection being performed to determine the presence or absence of the foreign matter, a second display 17 for displaying a radioscopic image, and a lead-containing flexible X-ray shielding curtain 18 of a slit configuration formed by a plurality of flexible curtain strips 18a and secured respectively to the front and rear walls 15a and 15b of the conveyor housing 1 so as to cover the conveyor openings 11 defined therein.

Fig. 2 illustrates a side view of the transport conveyor 2 in its entirety and Fig. 3 illustrates a top plan view thereof. As shown therein, the transport conveyor 2 includes a conveyor framework 21, a drive roller 22 supported by one end of the conveyor framework 21 by means of a drive shaft 22a, a driven roller 23 supported by the opposite end of the conveyor framework 21 by means of a driven shaft 23a, and a transport belt 24 in the form of an endless flat belt trained between the drive and driven rollers 22 and 23 and having upper and lower running portions. The conveyor framework 21 is made up of a generally elongated frame body 21a and a short frame piece 21b provided at a rear end thereof. The short frame piece 21b is supported by a bending support shaft 25 extending in a direction widthwise of the frame body 2 la so that the short frame piece 21b can bend relative to the frame body 21a about the bending support shaft 25.

A drive unit 30 including a power source 30a such as, for example, a drive motor is disposed at a front lower region of the flat transport belt 24, and an endless belt 30c is trained between a drive wheel 30b, provided in the drive unit 30, and a driven wheel 22b provided on the drive shaft 22a so that the flat transport belt 24 can be driven through a drive shaft 23a between and around the drive and driven rollers 22 and 23. In the illustrated embodiment, a ceiling member 21c is integrally disposed above the frame 21a and the short frame piece

21b in face-to-face relation with an inner surface of the upper running portion of the flat transport belt 24.

In Figs. 2 and 3, two X-ray shielding members 81 and 81 are fitted to the frame body 21 a forming a part of the transport conveyor 2 so as to extend a distance corresponding to the full width of the transport conveyor 2. These X-ray shielding members 81 and 81 are positioned forwardly and rearwardly, respectively, of the X-ray penetrating region 2a of the transport conveyor 2 which is in turn defined at a location generally intermediate of the length of the frame body 21a of the transport conveyor 2. The positioning of the X-ray shielding plates 81 in the manner described above and shown in Figs. 2 and 3 is effective to suppress leakage of X-rays, emitted from the X-ray emission source 3, and/or scattering rays in forward and rearward directions with respect to the transport conveyor 2.

Figs. 4 and 5 illustrate, on an enlarged scale, a portion of the short frame piece 21b of the transport conveyor 2 in a longitudinal sectional representation and a top plan representation, respectively. The short frame piece 21b shown in Fig. 4 includes a bracket 31 employed on each side of the transport conveyor 2 and rigidly secured to the short frame piece21b. The bracket 31 has a rear end portion formed with a generally rectangular slot 26 defined therein so as to extend in a direction conforming to the lengthwise direction of the transport conveyor 2 shown by the arrow FR. A support shaft 23a for the support of the driven roller 23 has each of its opposite ends formed with a rectangular sectioned slide portion 23b that is inserted into the corresponding rectangular slot 26 for sliding movement in a direction conforming to the lengthwise direction FR of the transport conveyor 23.

With the rectangular sectioned slide portions 23b of the support shaft 23a inserted into the associated rectangular slots 26 as best shown in Fig. 5, the support shaft 23a is supported by the short frame piece 21b for sliding movement along the slots 26 in directions opposite to each other and will not rotate relative

to the short frame piece 2 nib. It is to be noted that the driven roller 23 is rotatably mounted on the shaft 23a and, therefore, rotate as the transport belt 24 travels around and between the drive and driven rollers 22 and 23.

A front end of the short frame piece 21b, which is opposite to the rear end thereof discussed above, is bent to provide a bent portion 33 extending at right angles to the remaining portion of the short frame piece 21b, with a screw rod 27 rotatably passed through the bent portion 33. The screw rod 27 is also threaded through a plate member 28, and a coil spring 29 is interposed between the plate member 28 and the slide portion 23b of the support shaft 23a for urging the driven roller 23 in a rearward direction counter to the forward direction F.

Thus, it will readily be seen that by turning the screw rods 27 so as to move the respective plate members 28 relative to the short frame piece 21b in either the forward direction F or the rearward direction, the driven roller 23 can be moved along the slots 26 through the respective coil springs 29 in the forward F or rearward direction to thereby adjust the length of the transport conveyor 2 as a whole, more specifically the distance between the driven roller 23 and the drive roller 22. Specifically, adjustment of the transport conveyor 2 so as to increase the length thereof results in bringing the transport belt 24 under a proper tension even though the flat transport belts have varying lengths, thereby making it possible to achieve a favorable transport of the articles M.

In the illustrated embodiment, a ceiling member 34 is integrally provided on an upper portion of the short frame piece 2 lob in face-to-face relation with the inner surface of the upper running portion of the transport belt 24. The ceiling member 34 has its opposite side edges formed with respective steps 35 for allowing corresponding protruding edge portions 24a integral with opposite side edges of the backside of the transport belt 24 to move clear of the ceiling member 34. Another similar ceiling member 34 is provided on the side of the frame body 21a with steps 35 formed at opposite side edges thereof. By aligning the protruding edge portions 24a of the transport belt 24 with those steps 35, it is

possible to prevent the transport belt 24 from being laterally displaced in a direction widthwise of the transport conveyor 2.

The bending support shaft 25 referred to previously is positioned below an imaginary straight line L that connects respective axes of rotation of the drive and driven rollers 22 and 23 when the frame body 21a and the short frame piece 21b are rectilinearly aligned with each other as shown in Fig. 2. By so doing, when the frame body 21a and the short frame piece 21b are rectilinearly aligned with each other as shown in Fig. 2, the short frame piece 21b has a tendency to bend upwardly relative to the frame body 21a about the bending support shaft 25 by the effect of a resilient restoring force exerted by the flat transport belt 24. However, the short frame piece 21b is brought into contact with the ceiling member 34 rigid with the frame body 2 la to thereby prevent the short frame piece 21b from being further bent upwardly about the bending support shaft 25. Also, since the bending support shaft 25 is positioned below the level of the respective axes of rotation of the drive and driven rollers 22 and 23, the short frame piece 21b does not bend downwardly about the bending support shaft 25 relative to the frame body 21a. Accordingly, by the effect of the resilient restoring force of the flat belt 24, the frame body 21a and the short frame piece 21b are stably held in a straight position in which they are rectilinearly aligned with each other, thereby ensuring a successive forward transport of the articles M.

Fig. 6 illustrates, in a side view, a support structure by which the transport conveyor 2 is mounted inside the conveyor housing 1. A front end portion of the frame body 21a of the transport conveyor 2 has its opposite side portions formed with first engagement members 41 in the form of stud pins fixedly connected thereto so as to extend laterally outwardly therefrom, whereas the rear end portion of the short frame piece 2 Ib remote from the frame body 2 la has its opposite side portions formed with second engagement members 42 in the form of stud pins fixedly connected thereto so as to extend laterally

outwardly therefrom. On the other hand, a support member 30d is disposed below the drive unit 30 supported by the conveyor housing 1 and has its opposite left and right sides to which generally V-shaped arm members 5 each having first and second arms 51 and 52 are fitted, respectively. A free upper portion of the first arm 51 of each of the arm members 5 is formed with a first receiving member 53 in the form of recess defined therein whereas a free upper portion of the second arm 52 of each of the arm members 51 is similar formed with a second receiving member 54 in the form of recess defined therein. The transport conveyor 2 with the frame body 21a and the short frame piece 21b aligned rectilinearly with each other is supported by the arm members 51 with the stud pins 41 and 42 received within the first and second receiving recesses 53 and 54 as shown in Fig. 6 and is thus fitted to the conveyor housing 1 through the arm members 51.

The first and second stud pins 41 and 42 are in the form of a cylindrical projection protruding laterally outwardly from the corresponding side of the conveyor framework 21. The first receiving recesses 53 represent a generally U-shaped configuration opening rearwardly in a direction parallel to the lengthwise direction FR of the transport conveyor 2 so that the associated first stud pins 41 can be received therein, or engaged and disengaged therefrom, in a direction parallel to the lengthwise direction FR of the transport conveyor 2, but will not displace in a direction upwardly and downwardly so long as the first stud pins 41 are engaged in the first receiving recesses 53. On the other hand, the second receiving recesses 54 represent a generally U-shaped configuration opening upwardly so that the associated second stud pins 42 can be received in a downward direction, or engaged and disengaged therefrom in downward and upward directions generally perpendicular to the lengthwise direction FR of the transport conveyor 2, but will not displace in a direction parallel to the lengthwise direction FR of the transport conveyor so long as the second stud pins 42 are engaged in the second receiving recesses 54.

The operation of the X-ray foreign matter detecting apparatus of the structure described hereinabove will now be described.

When and while inspection is performed to determine the presence or absence of foreign matter in each of the articles M being successively transported, the frame body 21 a and the short frame piece 21b are held in a straight position in which they are rectilinearly aligned with each other, and the flat transport belt 24 trained between and around the drive and driven rollers 22 and 23 of the transport conveyor 2 is straightened inside the conveyor housing 1 as shown in Fig. 1. With the transport conveyor 2 so set inside the conveyor housing 1, the X-ray emission source 3 irradiates the articles M being successively transported by the transport conveyor 2 while resting on the flat transport belt 24 to perform an X-ray inspection to determine the presence or absence of the foreign matter in each of the articles M.

In the event that the transport conveyor 2 is desired to be removed in its entirety out of the conveyor housing 1 for cleansing thereof, starting from the condition in which the transport conveyor 2 is mounted on the arm members 5, the transport conveyor 5 is forcibly bent, causing the short frame piece 21b to pivot downwardly relative to the frame body 21a about the bending support shaft 25 as shown by the phantom line in Fig. 6. As the transport conveyor 2 is so bent, the first stud pins 41 at the front end portion of the transport conveyor 2 are moved horizontally in the rearward direction so as to be disengaged from the first receiving recesses 53 in the arm members 5. Thereafter, a rear portion of the transport conveyor 2 has to be shifted upwardly to allow the second stud pins 42 to be disengaged from the second receiving recesses 54.

The transport conveyor 2 so detached from the arm members 5 represents an effective length smaller than the length of the takeout opening 12 defined in the side wall 15c of the conveyor housing 1 as measured in a direction parallel to the lengthwise direction FR of the transport conveyor 2 and, accordingly, the transport conveyor 2 as a whole can easily and smoothly be

removed out of the conveyor housing 1 through the takeout opening 12. Also, since as a result of the bending of the transport conveyor 2 the distance between the respective axes of the drive and driven rollers 22 and 23 is shortened as compared with that exhibited when the frame body 21a and the short frame piece 21b are held in the straight position, the flat transport belt 24 can also be easily removed laterally outwardly from the drive and driven rollers 22 and 23.

Alternatively, the transport conveyor 2 can be removed out of the conveyor housing 1 by first pivoting the transport conveyor 2 about a common axis of the first stud pins 41 to allow the second stud pins 42 to be disengaged upwardly from the second receiving recesses 54, shifting the transport conveyor 2 generally horizontally in the rearward direction to allow the first stud pins 41 to be disengaged from the first receiving recesses 53 to thereby separate the transport conveyor 2 from the arm members 5 and hence the conveyor housing 1, and finally forcibly bending the transport conveyor 2 so that the short frame piece 21b can be bend about the bending support shaft 25 relative to the frame body 21a.

Resetting of the transport conveyor 2 into the conveyor housing 1 can also be performed easily and smoothly in a manner reverse to the removal therefrom from the conveyor housing 1 described above. Specifically, the cleansed transport conveyor 2 with the short frame piece 21b bent downwardly relative to the frame body 21a has to be introduced into the conveyor housing 1 through the takeout opening 12, followed by pivoting the short frame piece 21b upwardly about the bending support shaft 25 relative to the frame body 21a sa to allow the frame body 21a and the short frame piece 21b to assume the straight position with the first and second stud pins 41 and 42 consequently engaged in the first and second receiving recesses 53 and 54, respectively.

As described above, in view of the fact that the transport conveyor 2 used in the practice of the present invention is so designed and so configured that the overall length of the transport conveyor 2 can be reduced so as to allow it to

be removed out of the conveyor housing 1 through the takeout opening 12, the employment of the double-sided support structure for all of the openings in the conveyor housing 1 is effective to increase the strength of the conveyor housing 1 as a whole.

Also, the transport conveyor 2 can be detachably supported by the conveyor housing 1 with the first and second stud pins 41 and 42 received respectively in the first and second receiving recesses 53 and 54, without allowing the transport conveyor 2 to displace in not only a direction conforming to the heightwise direction of the conveyor housing 1, but also in a direction conforming to the lengthwise direction FR of the transport conveyor, wherefore the transport conveyor 2 will not undergo any rattling motion, thereby allowing the articles M to be successively transported thereby. In particular, since an undesirable upward and downward displacement of the articles M being transported can advantageously be suppressed, the radioscopic image of each of the articles M being transported that is displayed on the second display 17 after having been processed based on the X-rays detected by the X-ray detector 20 can be stabilized to thereby facilitate detection of the presence or absence of foreign matter in each of the articles M with high accuracy.

Fig. 7 illustrates a side view of a second preferred embodiment of the present invention. In this embodiment a single straight conveyor framework 21 is employed for the transport conveyor 2, instead of the conveyor framework 21 comprised of the frame body 21a and the short frame piece 21b which is employed in the previously described embodiment. In other words, the transport conveyor 2 employed in the practice of the second embodiment of the present invention is bendable in no way. This is a major difference the second embodiment of the present invention has relative to the previously described embodiment.

As is the case with that shown in Fig. 6, the conveyor framework 21 in Fig. 7 has its front end provided with the first stud pins 41 protruding laterally

outwardly therefrom and its rear end provided with the second stud pins 42 protruding laterally outwardly therefrom. On the other hand, the generally V-shaped first and second arm members 5 each having the first and second arms 51 and 52 are rigidly secured to the opposite sides of the support member 30d positioned below the drive unit 30. The free upper portion of the first arm 51 of each of the arm members 5 is formed with the first receiving recess 53 defined therein so as to represent a generally U-shaped configuration opening rearwardly in a direction parallel to the lengthwise direction FR of the transport conveyor 2 so that the associated first stud pins 41 can be received therein, or engaged and disengaged therefrom, in a direction parallel to the lengthwise direction FR of the transport conveyor 2, but will not displace in a direction upwardly and downwardly so long as the first stud pins 41 are engaged in the first receiving recesses 53. On the other hand, the free upper portion of the second arm 52 of each of the arm members 51 is similarly formed with the second receiving recess 54 defined therein so as to represent a generally U-shaped configuration opening upwardly so that the associated second stud pins 42 received in the downward direction, or engaged and disengaged therefrom in an upward direction generally perpendicular to the lengthwise direction FR of the transport conveyor 2, but will not displace in a direction parallel to the lengthwise direction FR of the transport conveyor so long as the second stud pins 42 are engaged in the second receiving recesses 54.

In the X-ray foreign matter detecting apparatus according to the second embodiment of the present invention, the transport conveyor 2 can be detachably supported by the conveyor housing 1 with the first and second stud pins 41 and 42 received respectively in the first and second receiving recesses 53 and 54, without allowing the transport conveyor 2 to displace in not only a direction conforming to the heightwise direction of the conveyor housing 1, but also in a direction conforming to the lengthwise direction FR of the transport conveyor, wherefore the transport conveyor 2 will not undergo any rattling

motion, thereby allowing the articles M to be successively transported thereby. Even though the transport conveyor 2 is not bendable such as in the previously described embodiment, selective removal and introduction of the transport conveyor 2 out of and into the conveyor housing 1 can easily be achieved. By way of example, where the transport conveyor 2 is to be removed out of the conveyor housing 1, it can be achieved by first pivoting the transport conveyor 2 about a common axis of the first stud pins 41 to allow the second stud pins 42 to be disengaged upwardly from the second receiving recesses 54 as shown by the phantom line in Fig. 7, and shifting the transport conveyor 2 generally horizontally in the rearward direction to allow the first stud pins 41 to be disengaged from the first receiving recesses 53 to thereby separate the transport conveyor 2 from the arm members 5 and hence the conveyor housing 1.

After engagement of the transport conveyor 2 with the conveyor housing 1 has been released in the manner described above, the transport conveyor 2 has to be displaced in a direction, for example, rearwardly of the conveyor housing 1 to allow the corresponding rear end portion thereof to protrude a distance outwardly of the conveyor housing 1 through the rear opening 11 in the rear wall 15b thereof and the front end portion of the transport conveyor 2 is then pulled outwardly from the conveyor housing 1 through the takeout opening 12 until the rear end portion of the transport conveyor 2 then protruding outwardly from the conveyor housing 1 through the rear opening 11 emerges outwardly from the conveyor housing 1 through the takeout opening 12. Alternatively, the transport conveyor 2 can be removed out of the conveyor housing 1 through the takeout opening 12 by inclining the transport conveyor 2 with respect to the heightwise direction of the conveyor housing 1, or the transport conveyor 2 can be pulled out in the lengthwise direction FR through one of the front and rear openings 11. In this way, the transport conveyor 2 can easily be removed out of the conveyor housing 1. Resetting of the transport conveyor 2 into the conveyor housing 1 can also be performed easily and

smoothly in a manner reverse to the removal therefrom from the conveyor housing 1 described above.

Figs. 8 and 9 illustrate a third preferred embodiment of the present invention, in which Fig. 8 is a side view of the transport conveyor 2 and Fig. 9 is a side view of the transport conveyor 2 having been bent in readiness of the removal of the transport conveyor 2 out of the conveyor housing 1. In this third embodiment shown in Figs. 8 and 9, the conveyor framework 21 of the transport conveyor 2 is bendable about the bending support shaft 25 and is therefore made up of the frame body 21a and the short frame piece 21b pivotally connected with each other by the bending support shaft 25 in a manner similar to that shown in and described with reference to Fig. 2. Thus, it will readily be seen that even in the third embodiment of the present invention the transport conveyor 2 has its length that can be shortened by bending the short frame piece 21b relative to the frame body 21a about the bending support shaft 25.

The conveyor framework 21 has its front end provided with the first stud pins 41 protruding laterally outwardly therefrom and its rear end provided with third stud pins 43 protruding laterally outwardly therefrom. On the other hand, the generally V-shaped first and second arm members 5 each having the first and second arms 51 and 52 are rigidly secured to the opposite sides of the support member 30d positioned below the drive unit 30. The free upper portion

of the first arm 51 of each of the arm members 5 is formed with the first receiving recess 53 defined therein so as to represent a generally U-shaped configuration opening rearwardly in a direction parallel to the lengthwise direction FR of the transport conveyor 2 so that the associated first stud pins 41 can be received, or engaged and disengaged therefrom, in a direction parallel to the lengthwise direction FR of the transport conveyor 2, but will not displace in a direction upwardly and downwardly so long as the first stud pins 41 are engaged in the first receiving recesses 53. On the other hand, the free upper portion of the second arm 52 of each of the arm members 51 is similarly formed with a

third receiving recesses 55 defined therein so as to represent a generally U-shaped configuration opening forwardly in a direction parallel to the lengthwise direction FR of the transport conveyor 2 so that the associated third stud pins 43 can be received, or engaged and disengaged therefrom, in a direction counter to the direction in which the first receiving recess 53 receives the first stud pins 41, but will not displace in a direction upwardly and downwardly so long as the third stud pins 43 are engaged in the third receiving recesses 55.

In the X-ray foreign matter detecting apparatus according to the third embodiment of the present invention, the transport conveyor 2 is forcibly bent to represent a generally V-shaped configuration by lifting a portion of the transport conveyor 2 adjacent the bending support shaft 25 upwardly in a direction as shown by the arrow U in Fig. 9. Bending of the transport conveyor 2 in this way causes the short frame piece 21b to pivot downwardly relative to the frame body 21a about the bending support shaft 25 as shown in Fig. 9, with the first and third stud pins 41 and 43 consequently disengaged from the associated first and third receiving recesses 53 and 55. Once this occurs, the length of the transport conveyor 2 is shortened and, accordingly, removal of the transport conveyor 2 can readily be achieved by pulling the shortened transport conveyor 2 laterally outwardly through the takeout opening 12 (shown in Fig. 1). Also, as is the case with the first embodiment of the present invention, the flat transport belt 24 can be easily removed from the conveyor framework 21.

Resetting of the transport conveyor 2 into the conveyor housing 1 can also be performed easily and smoothly in a manner reverse to the removal therefrom from the conveyor housing 1 described above. Specifically, by introducing the transport conveyor 2 then in a generally V-shaped configuration into the conveyor housing 1 through the takeout opening 12 and then by pushing that portion of the transport conveyor 2 adjacent the bending support shaft 25 in a direction downwardly as shown by the arrow D in Fig. 9 to straighten the transport conveyor 2, i. e. , bringing the frame body 21a and the short frame piece

21b to the straight position, the first and third stud pins 41 and 43 are engaged respectively in the first and third receiving recesses 53 and 55 as shown in Fig. 8, thereby completing resetting of the transport conveyor 2 inside the conveyor housing 1.

In this X-ray foreign matter detecting apparatus according to the third embodiment of the present invention, other than the structure in which the conveyor framework 21 is made up of the frame body 21a and the short frame piece 21b which are pivotally connected together by means of the bending support shaft 25, an alternative is possible in which, for example, the short frame piece 21b which is a part of the conveyor framework 21 is slidably connected with the frame body 21a which is another part of the conveyor framework 21 for sliding movement between extended and retracted positions in a direction conforming to the lengthwise direction FR of the transport conveyor 2. In such case, disengagement of the first and third stud pins 41 and 43 from the associated first and third receiving recesses 53 and 55 to remove the transport conveyor 2 out of the conveyor housing 1 can be performed while the short frame piece 21b is moved to the retracted position.

Also, in any one of the foregoing first and second embodiments of the present invention, one or a plurality of clamp elements for locking the transport conveyor 2 to the arm members 5 may be employed. More specifically, while the clamp element is made up of a clamping member and a hook with the clamping member secured to one or both of the arm members 5 and with the hook secured to the conveyor framework 21. In this design, by pulling the clamping member downwardly while having been engaged with the hook, the conveyor framework 21 can be locked to the arm members 5. Separation of the transport conveyor 2 from the arm members 5 can be performed by manipulating the clamping member so as to be disengaged and released from the hook. The use of the clamping element is effective to further suppress up and down displacement of the transport conveyor 2 to thereby allow the X-ray inspection to be enhanced with high accuracy.

Claims

CLAIMS 1. An X-ray foreign matter detecting apparatus which comprises : a conveyor housing ; a transport conveyor removably accommodated within the conveyor housing for transporting articles successively across the conveyor housing, the transport conveyor including a conveyor framework and having a length greater than a length of the conveyor housing as measured in a direction conforming to a direction of transport of the articles; and a bending support shaft extending across the transport conveyor to thereby pivotally connect one end portion of the conveyor framework to a frame body forming the other portion of the conveyor framework.
2. An X-ray foreign matter detecting apparatus which comprises: a conveyor housing; and a transport conveyor removably accommodated within the conveyor housing for transporting articles successively across the conveyor housing, the transport conveyor including a conveyor framework and having a length greater than a length of the conveyor housing as measured in a direction conforming to a direction of transport of the articles; wherein one end portion of the conveyor framework is slidably connected with the other portion of the conveyor framework such that the length of the transport conveyor can be shortened when such one end portion of the conveyor framework is slid inwardly of and relative to such other portion of the conveyor framework.
3. The X-ray foreign matter detecting apparatus as claimed in Claim 1 or 2, wherein the conveyor framework of the transport conveyor is provided with a first engagement member, and the conveyor housing is provided with a first receiving member for receiving the first engagement member in a direction parallel to the direction of transport of the article to thereby restrict up and down displacement of the first engagement member in a direction generally perpendicular to the transport conveyor.
4. The X-ray foreign matter detecting apparatus as claimed in Claim 3, wherein the conveyor framework of the transport conveyor is also provided with a second engagement member, and the conveyor housing is provided with a second receiving member for receiving the second engagement in a downward direction to thereby restrict forward and rearward displacement of the second engagement member in the direction generally parallel to the transport conveyor.
5. Apparatus as claimed in Claim 3 or Claim 4, wherein the conveyor framework of the transport conveyor is provided with a third engagement member, and the conveyor housing is provided with a third receiving member for restricting up and down displacement of the first engagement member in a direction generally perpendicular to the transport conveyor, the third receiving member receiving the third engagement member in a direction parallel to the direction of transport, but counter to the direction in which the first receiving member receives the first engagement member.
6. An X-ray foreign matter detecting apparatus which comprises: a conveyor housing ; a transport conveyor removably accommodated within the conveyor housing for transporting articles successively across the conveyor housing, the transport conveyor including a conveyor framework and having a length greater than a length of the conveyor housing as measured in a direction conforming to a direction of transport of the articles; first and second engagement members provided in the conveyor framework of the transport conveyor ; and first and second receiving members provided in the conveyor housing for cooperating with the first and second engagement members, respectively; said first receiving member receiving the first engagement member in a direction generally parallel to the direction of transport of the article to thereby restrict up and down displacement of the first engagement member; said second receiving member receiving the first engagement member in a downward direction to thereby restrict forward and rearward displacement of the second engagement member.
7. The X-ray foreign matter detecting apparatus as claimed in any one of the preceding claims, further comprising : an X-ray emission source for emitting X-rays towards the transport conveyor from above; an X-ray detector for detecting, at a position below the transport conveyor, the X-rays which have been emitted from the X-ray emission source and have subsequently penetrated through an X-ray penetrating region of the transport conveyor; and X-ray shielding members positioned forwardly and rearwardly of the X-ray penetrating region, respectively, with respect to the direction of transport of the articles, so as to extend in a direction widthwise of the transport conveyor for shielding the X-rays.
8. The X-ray foreign matter detecting apparatus as claimed in any one of the preceding claims, wherein the conveyor housing includes frame members positioned leftwards and rightwards of the direction of transport of the articles by the transport conveyors, respectively.
9. X-ray foreign matter detecting apparatus substantially as hereinbefore described with reference to any of the examples shown in the accompanying drawings.