The present invention relates to a vessel sterilization apparatus for sterilizing a vessel held by a gripper of a rotary-type vessel conveying device by irradiating the vessel with electron beam during conveyance thereof while being rotated.
A vessel sterilization apparatus, which sterilizes a vessel conveyed in a state of being held by a gripper of a vessel conveying device by irradiating the vessel with electron beam from an electron beam irradiator, is conventionally known (for example, refer to Patent Document 1). The electron beam irradiator described in this Patent Document 1 is provided with a plurality of vessel holding means (grippers) around a rotary body at an equal interval in a circumferential direction, and the vessels are held by such vessel holding means, respectively, and are rotated and conveyed by the rotation of the rotary body. The electron beam irradiator is arranged along a conveying path so as to irradiate the vessel with the electron beam during the conveyance thereof in the state of being held by the vessel holding means.
In a conventional electron beam sterilization apparatus, an electron beam irradiating surface of the electron beam irradiator emitting the electron beam generally has a flat surface shape more than the structure of the invention disclosed in the above Patent Document 1. On the other hand, in the rotary-type vessel conveying device of the structure mentioned above, the vessel conveying path has a circular-arc shape, and a vessel to be conveyed and sterilized has, for example, a rectangular outer configuration, an angle of a surface of the vessel to be irradiated with the electron beam with respect to the irradiating surface of the electron beam irradiator gradually changes during the movement through the circular-arc path, so that the irradiating efficiency was not good, thus providing a problem.
Furthermore, in the rotary-type vessel conveying device, a distance between the irradiating surface of the electron beam irradiator and a surface of the vessel to be irradiated changes in accordance with the movement of the vessel. As mentioned, if the distance between the irradiating surface and the surface of the vessel to be irradiated changes, the vessel irradiating electron beam changes, which results in ineffective sterilization achievement, thus being not desirable.
The present invention was conceived to solve the above defect, and an object thereof is to provide a vessel sterilization apparatus capable of maintaining a parallel condition of an angle constituted by a surface of a vessel to be irradiated and an electron beam irradiating surface of an electron beam irradiator in an irradiation region in which the vessel is irradiated with the electron beam emitted through the irradiating surface of the electron beam irradiator, and another object thereof is to provide a vessel sterilization apparatus capable of maintaining a constant distance between the vessel and the irradiating surface.
The present invention includes a gripper arranged in an outer periphery of a rotary body so as to hold a vessel, drive means that rotates the rotary body, electron beam irradiating means that has a flat electron beam irradiating surface and that irradiates the vessel, conveyed with being held by the gripper, with the electron beam, and rotating means that rotates the gripper with respect to the rotary body, wherein areas in which the gripper is rotated are formed in an irradiating region in which the electron beam is emitted through the irradiating surface so that the irradiating surface and the surface of the vessel to be irradiated are opposed to each other in a constant direction.
The invention defined in claim 2 is characterized by further including forward/rearward moving means that moves forward and rearward the gripper with respect to the irradiating surface, wherein, in the irradiation region, a distance between the irradiating surface and the surface of the vessel to be irradiated is maintained substantially constant.
The invention defined in claim 3 is characterized in that the gripper is rotated by substantially 180 degrees in the irradiation region.
According to the vessel sterilization apparatus of the present invention, in the irradiation region in which the electron beam is emitted through the irradiating surface of the electron beam irradiator, there is formed an area in which the irradiating surface and the surface of the vessel to be irradiated are opposed to each other in a constant direction. That is, there is provided the area in which the parallel condition between the irradiating surface and the surface of the vessel to be irradiated are maintained as far as the vessel has a rectangular outer configuration, so that the vessel is effectively irradiated with the electron beam, thus being sterilized efficiently.
A irradiation region
B area to be opposed to each other in a constant direction
D area to be opposed to each other in a constant direction
6 gripper
8 vessel (resin bottle)
12
a irradiating surface
14 rotary body
52 rotating means (pinion gear)
58 rotating means (segment gear)
62 rotating means (rotational cam)
The vessel sterilization apparatus includes grippers disposed to peripheral portions of a rotary body rotated and driven by driving means, rotating means that rotates the grippers with respect to the rotary body and an electron beam irradiator having a flat irradiating surface and irradiating vessels, conveyed in a state of being held by the grippers, with an electron beam, and achieves an object of effectively irradiating a surface of the vessel to be irradiated with the electron beam emitted from the irradiating surface by the structure provided with an area in which the irradiating surface and the vessel surface to be irradiated are opposed in a constant orientation.
Hereunder, the present invention will be described with reference to an embodiment shown in the accompanying drawings.
A vessel 8 held by each of the grippers 6 of a vessel conveying device 4 disposed within a sterilization chamber 2 is a bottle formed of a resin material, and as shown in
The resin bottles 8 to be conveyed in the sterilization chamber 2 are continuously conveyed by an air conveyer, not shown, in which the resin bottles 8 are separated at a predetermined interval by an infeed screw or the like and then conveyed into an introduction chamber arranged on the upstream side of the sterilization chamber. Inside the introduction chamber, a rotary-type supply wheel is disposed, and the resin vessels 8 are held by the vessel holding means of the supply wheel, rotated and conveyed, and then transferred to the inlet wheel formed on the inlet side of the sterilization chamber 2, thus being supplied into the sterilization chamber 2. The inlet wheel within the sterilization chamber 2 is provided with the vessel holding means (see
Each of the resin bottles 8 is transferred to the vessel conveying device 4 from the inlet wheel in the sterilization chamber 2. In this embodiment, the resin bottle 8 held at the lower side of the flange 8c by the vessel holding means 10 of the inlet wheel is held at the upper side than the flange 8c of the neck portion 8a by the gripper 6 of the vessel conveying device 4. The resin bottle 8 held by the gripper 6 of the vessel conveying device 4 is conveyed while being rotated and sterilized by the irradiation with the electron beam, which will be explained hereinafter, and thereafter, is transferred to the vessel holding means 10 on the outlet wheel (not shown) disposed on the downstream side of the vessel conveying device 4. Thereafter, the resin bottle 8 is conveyed while being rotated and discharged from the inside of the sterilization chamber 2 so as to be subjected to the succeeding process. Further, a conveying path, which is not shown, other than the vessel conveying device 4 is one example, and may have a structure other than the one described above.
The sterilization chamber 2 is defined by lead wall sections for shielding the resin bottle 8 from the electron beam or X-ray (braking X-ray) so as not to leak outside at a time when the resin bottle 8 is irradiated with the electron beam for the sterilization thereof. The electron beam irradiator (the entire of which is not shown in figure, but only the irradiating window 12 through which the electron beam is emitted) is disposed on a front surface side (upper side in
The rotary-type vessel conveying device 4 according to this embodiment has a characteristic feature in an action of the gripper 6 disposed in the electron beam irradiation region “A” in front of the irradiating surface 12a. Hereunder, the structure of the vessel conveying device provided with the grippers 6 will be explained. The grippers 6 are arranged at the outer peripheral portion of a rotary disc 16 constituting the rotary body 14 at an equal interval between adjacent ones in the circumferential direction thereof. Two guide roller assemblies 20 (see
The guide roller assemblies 20 are disposed on an annular plate 22 coupled to the outer periphery of the rotary disc 16, and as shown in
A cylindrical case 38 is perpendicularly attached to the front end (i.e., end portion on the radially outward direction of the rotary body 14) of the horizontal forward/rearward moving rod 18. A perpendicular rotating shaft 42 is supported to be rotatable through this cylindrical case 38 through ball bearings 40, 40. The gripper 6 is mounted to a lower end portion of the perpendicular shaft 42. Although the details of this gripper 6 is not described herein, gripping members 6b having gripper portions facing each other are attached to lower ends of two plate springs 6a disposed in parallel on both sides of the gripper 6, and when the neck portion 8a of the resin bottle 8 is pushed between the paired gripping members 6b from the front side (right side shown in
A tension spring 44 is disposed between a spring mount portion 18a formed to the loser surface side of a rear end portion of the forward/rearward moving rod 18 (i.e., radially inside portion of the rotary body 14) and a spring mount portion 22a fixed on an annular plate 22 coupled to an outer peripheral portion of the rotary disc 16 to thereby always urge the forward/rearward moving rod 18 toward the radially outward direction of the rotary body 14. Furthermore, a cam follower 46 is mounted on an upper surface side of the rear end portion of the forward/rearward moving rod 18. Further, a forward/rearward moving cam 50 is mounted to an outer peripheral portion on the lower surface side of a fixing side mount plate 48 disposed above the rotary body 14, and the cam follower 46 of the forward/rearward moving rod 18 is pushed by urging force of the tension spring 44. Accordingly, when the rotary body 14 is rotated, the cam follower 46 moves along a cam surface 50a (see
In this embodiment, when the rectangular-shaped resin bottle 8 held by the gripper 6 and conveyed as shown in
A pinion gear 52 is fixed to an upper end portion of the perpendicular rotating shaft 42, and a horizontal support plate 54 is fixed to an upper end portion of the cylindrical case 38 fixed perpendicularly to the front end portion of the forward/rearward moving rod 18. A fulcrum pin 56 is fixed on the support plate 54, and an intermediate portion of a segment gear 58 is supported to be rotatable. The segment gear 58 is meshed with the pinion gear 52 of the perpendicular rotating shaft 42. Furthermore, a cam follower 60 is mounted to an upper surface of a rear side end portion of the segment gear 58. Incidentally, a rotational cam 62 is fixed to an upper surface side of the fixing side mount plate 48. According to the structure mentioned above, by the tension spring 64 interposed between the spring mount portion 58a fixed to the lower side of the cam follower 60 and the spring mount portion 54a on the support plate 54, the cam follower 60 attached to the rear end of the segment gear 58 is elastically contacted to the cam surface 62a (
In this embodiment, as shown in
Hereunder, function or operation of the vessel sterilization apparatus of the structure mentioned above will be described.
The resin bottles 8 conveyed from the outside into the sterilization chamber 2 and held by the vessel holding means 10 of the inlet wheel, not shown, are transferred to the grippers 6, respectively, at the transfer-position to the vessel conveying device 4. These grippers 6 are operated to perform the forward/rearward movement and rotational movement, which are mentioned hereinafter, in the electron beam irradiation region “A” positioned in front of the irradiating surface 12a of the electron beam irradiator. However, in regions other than this irradiation region 12, the grippers 6 are moved while directing the resin bottle receiving sides (right side in
The gripper 6 holding the resin bottle 8 approaches the electron beam irradiating region “A” by the rotation of the rotary body 14, the cam follower 60 mounted to the rear end of the segment gear 58 meshed with the pinion gear 51 comes into engagement with the cam surface 62a of the rotational cam 62. Subsequently, the cam follower 46 of the horizontal forward/rearward moving rod 18 to which the cylindrical case 38 into which the perpendicular rotating shaft 42, to the lower end portion of which the gripper 6 is mounted, is inserted, is engaged with the cam surface 50a of the forward/rearward moving cam 50.
When the cam follower 60 of the segment gear 58 moves on the rotational cam 62 and enters the first area “B” of the electron beam irradiation region “A”, the segment gear 58 is slightly rotated step by step in accordance with the movement of the cam follower 60 on the cam surface 62a, and the pinion gear 52 is then rotated, thereby rotating the gripper 6 fixed to the lower end portion of the rotating shaft 42 to which the pinion gear 52 is mounted, and the resin bottle 8 is moved (see resin bottle shown 8B, 8C, 8D in
When the gripper 6 further moves and enters the second area “C” of the irradiation region “A”, the segment gear 58 is largely rotated by the change of the shape of the rotational cam 62, and the pinion gear 52 is hence rotated by 180 degrees. In this embodiment, during the movement of the pinion gear 52 from one end to the other end of the segment gear 58 in the engaged condition, the pinion gear 52 rotates substantially by 180 degrees. According to this rotation of the pinion gear 52, the gripper 6 fixed to the lower end portion of the rotating shaft 42 is also rotated by 180 degrees, the surface of the resin bottle 8 directing to the irradiating surface side 12a in the first area “B” (see resin bottle 8 shown with 8D, 8DE, 8E, 8EF, 8F in
When the gripper 6 further moves and enters the third area “D” of the irradiation region “A”, as the rotational cam 62 moves on the cam surface 62a, the segment gear 58 is rotated slightly step by step, and by rotating the pinion gear 52, the gripper 6 fixed to the lower end of the rotating shaft 42 is rotated and the surface of the resin bottle 8 directing the irradiating surface 12a side is moved while maintaining substantially parallel state with the irradiating surface 12a (refer to resin bottle 8 shown with 8F, 8G. 8H in
On the other hand, the cam follower 46 mounted to the rear end portion of the horizontal rod 18 comes into engagement with the cam surface 50a of the forward/rearward moving cam 50. This cam surface 50a has a shape substantially straight in parallel with the irradiating surface 12a in the electron beam irradiation region “A”, so that the gripper 6 supported at the front end portion of the horizontal rod 18 is pulled radially inward in accordance with the shape of the cam surface 50a and is moved substantially straightly in parallel with the irradiating surface 12a. In a case where such mechanism for moving the gripper in the forward or rearward direction is not provided, the resin bottle 8 held by the gripper 6 moves so as to describe a circular-arc locus along the outer periphery of the rotary body 14, and hence, since the distance between the resin bottle 8 and the irradiating surface 12a changes in accordance with this movement, which may result in uneven irradiation to the resin bottle 8 with the electron beam. In this viewpoint, however, according to the present embodiment, the resin bottle 8 can be moved with the constant distance being maintained between the resin bottle 8 and the electron beam irradiating surface 12a, and hence, the irradiation dose of the electron beam from the irradiating surface 12a can be made uniform. Further, it is to be noted that the mechanism for moving the gripper 6 forward or rearward is not limited to a sliding mechanism formed from the cam 50, and a mechanism utilizing a link mechanism may be applied. Furthermore, the resin bottle 8 having been subjected to the electron beam irradiation is thereafter discharged from the vessel conveying device 4. However, since the gripper holding the resin bottle 8 is rotated by 180 degrees in the second area “C” of the irradiating region “A”, when the resin bottle 8 is discharged, the gripper 6 is again rotated by 180 degrees so as to face the same direction as that in the supply time.
In this second embodiment, the shape of a gripper 106 and a structure of rotating means (servo-motor in this embodiment) for rotating the gripper 106 are different from those of the first embodiment, and the other structures are substantially the same, so that different structures are only described and the other structures are omitted in their explanations by applying the same reference numerals.
In the first embodiment, the rotating means for rotating each of the grippers 6 includes the pinion gear 52 fixed to the upper end portion of the perpendicular rotating shaft 42 to which the grippers 6 are mounted, the segment gear 58 to be meshed with the pinion gear 52, the rotational cam 62 for rotating the segment gear 58 and so on. In this second embodiment, however, the gripper 6 is rotated by a servo-motor 170. The servo-motor 170 is mounted, in a downwardly directed fashion, through a bracket 172, to the upper end portion of the cylindrical case 38 fixed to the front end portion of the horizontal rod 18 which moves forward/rearward in the radial direction of the rotary body 14. The servo-motor 170 has a driving shaft 170a to which a drive gear 174 is fixed and is meshed with the pinion gear 52. Further, the forward/rearward moving means (which is composed of the forward/rearward moving cam 50, the cam follower 46, the spring 44, the guide roller assembly 20, and so on) for moving forward or rearward the gripper 6 in the radial direction of the rotary body 14 has the same structure as that of the first embodiment.
The gripper 106 of this embodiment, as shown in
In this embodiment, since the servo-motor 170 is utilized as rotating means for rotating the gripper 6, in accordance with the revolving movement (revolution) of the gripper 106, the resin bottle 8 can be rotated by an optional angle, and as like as in the first embodiment, the irradiating surface 12a of the electron beam irradiator and the surface of the resin bottle 8 to be irradiated with the electron beam can be moved in a state in which both the surfaces are opposed in a constant direction. That is, as far as the resin bottle 8 has a rectangular configuration, the resin bottle 8 can be moved with one surface thereof facing the irradiating surface 12a in parallel therewith. Furthermore, the gripper 6 in the first embodiment has a structure in which the resin bottle 8 is inserted thereinto from one direction, and therefore, if the resin bottle is inverted by 180 degrees in the electron beam irradiating region “A”, it is necessary to again rotate the resin bottle 8 by 180 degrees to return the original state for discharging the resin bottle 8 and holding the subsequently conveyed resin bottle 8. However, the gripper 106 according to the second embodiment has the same structures on its front and rear surface sides, so that the resin bottle 8 can be inserted from both the front and rear surface sides, and even if the resin bottle 8 is rotated by 180 degrees, it is not necessary to again return the bottle 8 to original position. That is, in the case where one surface of the resin bottle 8 directing to the irradiating surface 12a in the first area “B” (
Number | Date | Country | Kind |
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2007-310412 | Nov 2007 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2008/070390 | 11/10/2008 | WO | 00 | 5/18/2010 |