This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2004-091871, filed Mar. 26, 2004, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a tube-plug extracting apparatus capable of automatically extracting a plug from a test tube containing a sample, such as blood.
2. Description of the Related Art
A tube-plug extracting apparatus is described and shown in Paragraph 0007 and FIG. 1 of Jpn. Pat. Appln. KOKAI Publication No. 5-228379. In this apparatus, a plug that is put into a test tube is chucked by a distal end portion of an extracting arm with the tube held by a tube retainer. The extracting apparatus is constructed so that the chucked plug can be automatically extracted from the test tube in the direction in which the plug is pulled off by raising the extracting arm with a cylinder for vertical sliding.
The extracting arm of this apparatus has plug chucking claws on its distal end. Further, the extracting arm has a mechanism that turns the chucked plug through a predetermined angular range around its central axis in conjunction with a tilt guide as the arm is pulled up by the cylinder for vertical sliding.
Test tubes for use as sample containers include test tubes of different bores and lengths (φ13×75 mm, φ13×100 mm, φ16×75 mm, φ16×100 mm, etc.). There are also various types of plugs for these test tubes, including push-in rubber plugs, cork plugs, threaded screw plugs, etc.
However, the tube-plug extracting apparatus described in Jpn. Pat. Appln. KOKAI Publication No. 5-228379 is configured only to extract adaptive standard-typed plugs from test tubes of a fixed size. In other words, it is not provided with any means for adaptation to test tubes of different sizes or plug types. Thus, a lower-limit stop position of the cylinder that vertically moves the extracting arm cannot be adjusted corresponding to a change of length of the test tubes.
In the means for twisting the plug to extract it in conjunction with the tilt guide, an end roller on the extracting arm is configured to be pressed against a slope of the tilt guide by the urging force of a tension spring. This apparatus is designed to reduce the necessary force for plug extraction by turning the plug through only a certain angular range as it is extracted. Thus, the apparatus cannot remove a screw plug that requires several turns for its extraction.
The object of the present invention is to provide a tube-plug extracting apparatus capable of quickly accurately extracting plugs of any of different types from test tubes of different sizes regardless of the tube size and type of plug attached to each test tube.
A tube-plug extracting apparatus according to the present invention comprises a clamping mechanism, movable frame, chucking mechanism, rotation mechanism, and vertical motion mechanism. The clamping mechanism holds a test tube upright in a plug extracting position. The movable frame is located over the plug extracting position and moves in a vertical direction without rotating. The chucking mechanism is attached to the movable frame for rotation around a vertical axis and chucks a plug attached to the test tube in the plug extracting position. The rotation mechanism is attached to the movable frame and rotates the chucking mechanism with the plug chucked thereby around the vertical axis. The vertical motion mechanism has ball screws and a drive motor and moves the movable frame in a direction to extract the plug while the chucking mechanism chucking the plug is rotating. The ball screws have an extra stroke in which a lower-limit stop position of the movable frame, along with the vertical motion mechanism, is shifted from a chucking position for the plug attached to the test tube of a maximum size to a chucking position for the plug attached to the test tube of a minimum size. The drive motor drives the ball screws. It actuates the ball screws to move the movable frame according to the size of the test tube held in the plug extracting position.
Vertical guide rails and sliders are provided in order to move the movable frame in the vertical direction without rotating it. The vertical guide rails are paired and located left and right outside the movable frame. The sliders are fixed to the movable frame and engage the vertical guide rails. As the sliders are slidingly guided along the vertical guide rails, the movable frame moves in the vertical direction without rotating.
In the tube-plug extracting apparatus according to the invention, use of only one ball screw can fulfill a necessary function. A pair of ball screws are provided in order to stabilize the operation of the movable frame that is mounted with the chucking mechanism and the rotation mechanism. Preferably, in this case, the paired ball screws are arranged individually on the opposite sides of a region in which the movable frame moves.
Preferably, the chucking mechanism includes a cylinder and a chuck. The cylinder is rotatably supported on the movable frame and rotated by the rotation mechanism. The chuck is provided on a lower end portion of the cylinder for rotation integral with the cylinder and is opened or closed as a piston rod attached to the cylinder advances or retreats.
Preferably, moreover, the rotation mechanism comprises a driven sprocket wheel fixed to the cylinder, a drive motor fixed to the movable frame, a driving sprocket wheel mounted on a rotating shaft of the drive motor, and an endless chain wound around the driving sprocket wheel and the driven sprocket wheel.
In the tube-plug extracting apparatus according to the invention, the test tube is held by the clamping mechanism, and the plug on the tube is extracted in a manner such that the chucking mechanism chucking the plug is rotated as the movable frame is raised in the direction to extract the plug. Thus, the plug can be extracted quickly and accurately from the tube regardless of to the size of the tube and type of plug attached to the tube.
Additional advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
A tube-plug extracting apparatus 100 according to an embodiment of the present invention will now be described with reference to
In
The lower end portion of the tube holder 3 has a pair of flanges, upper and lower. Thus, an annular groove 4 is provided between the flanges. The holder 3 is provided with a leaf spring, which can hold the test tubes 1 and 1a of different bores in a socket portion. The tube-plug extracting apparatus 100 is located over a transport path 5 on which the tube holder 3 fitted with the tube 1 or 1a is transported intermittently at given intervals. The transport path 5 is composed of a belt conveyor 6 and conveyor rails 7 and 8.
The belt conveyor 6 is circulated while carrying the tube holder 3 intermittently. As shown in
The tube-plug extracting apparatus 100 comprises a fixed frame 10, clamping mechanism 11, movable frame 20, chucking mechanism 30, rotation mechanism 40, and vertical motion mechanism 50. The fixed frame 10 is set vertically in the plug extracting position, spanning the transport path 5.
The clamping mechanism 11 is located inside the lower part of the fixed frame 10 and can hold the test tubes 1 and 1a of different bores in the plug extracting position. The movable frame 20 is located over the plug extracting position and attached to the fixed frame 10 so as to be movable in the vertical direction without rotating. The chucking mechanism 30 is mounted on the movable frame 20 for rotation around a vertical axis and chucks the plug 2 attached to the test tube 1 or 1a that is held in the plug extracting position. The rotation mechanism 40 is attached to the movable frame 20 and rotates the chucking mechanism 30 together with the plug 2 chucked thereby around the vertical axis. The vertical motion mechanism 50 keeps the chucking mechanism 30 rotating together with the plug 2 therein as it moves the movable frame 20 in the direction to extract the plug 2.
As shown in
As shown in
As shown in
As shown in
The piston rod 25a of the cylinder 25 has a chuck operating block 25b and a rod bottom nut 25c on its end portions, individually. The top surface of the chuck operating block 25b is spherically curved. The chuck operating block 25b is situated between the top engaging portions 28a and 29a and the arcuate engaging portions 28b and 29b of the chuck members 28 and 29. The rod bottom nut 25c is situated below the arcuate engaging portions 28b and 29b of the chuck members 28 and 29.
When the piston rod 25a ascends, a spherical part of the chuck operating block 25b abuts against the top engaging portions 28a and 29a of the chuck members 28 and 29, thereby urging the chuck members 28 and 29 to close. When the piston rod 25a descends, the bottom surface portion of the chuck operating block 25b abuts against the arcuate engaging portions 28b and 29b of the chuck members 28 and 29, thereby urging the chuck members 28 and 29 to open.
Plug nipping portions 28d and 29d are formed on the lower end portions of the chuck members 28 and 29. The plug nipping portions 28d and 29d that fit the plug 2 with a maximum outside diameter. Spikes 33 and 34 are arranged on the inner peripheral surfaces of the plug nipping portions 28d and 29d, respectively. As shown in
As shown in
The vertical motion mechanism 50 comprises a pair of ball screws 51 and 52 and a drive motor 53. The ball screws 51 and 52 have an extra stroke besides a stroke in which the movable frame 20 is slid to extract the plug 2. In the extra stroke, the movable frame 20 is moved so that a lower-limit stop position of the chuck 27 is shifted from a chucking position for the plug 2 that is attached to the large-sized test tube 1 to a chucking position for the plug 2 that is attached to the small-sized test tube 1a. The drive motor 53 is a stepping motor that actuates the ball screws 51 and 52. In the tube-plug extracting apparatus 100, the drive motor 53 actuates the ball screws 51 and 52 to move the movable frame 20 corresponding to the length of the test tube in the vertical direction.
The vertical motion mechanism 50 will be described further in detail. The ball screws 51 and 52 are composed of screw shafts 51a and 52a and nut pieces 51b and 52b. The screw shafts 51a and 52a are supported on the fixed frame 10 so as to extend parallel to the vertical guide rails 23 and 24. The screw shafts 51a and 52a have a stroke long enough to allow the lower-limit stop position of the chuck 27 to be shifted from the chucking position for the plug 2 that is attached to the large-sized test tube 1 to the chucking position for the plug 2 that is attached to the small-sized test tube 1a.
The screw shafts 51a and 52a are inserted in the nut pieces 51b and 52b, respectively, which are fixed to the movable frame 20 by a mounting member 54. Sprocket wheels 55 and 56 are mounted on the top parts of the screw shafts 51a and 52a, respectively. As shown in
The following is a description of the operation of the tube-plug extracting apparatus 100. In the state shown in
A stepping motor is used as the drive motor 53. Therefore, the distance and speed of vertical movement of the movable frame 20 that is mounted with the chucking mechanism 30 can be easily adjusted by properly controlling the rotational speed of the drive motor 53. In an example of control, the movable frame 20 first starts to be moved at low speed. After the plug 2 is extracted, the movable frame 20 is raised at high speed. In this way, the plug 2 can be extracted without allowing the blood sample in the test tube 1 to scatter.
The extracted plug 2 is dropped into a receiving box 60 of a recovery device shown in
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general invention concept as defined by the appended claims and their equivalents.
Number | Date | Country | Kind |
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2004-091871 | Mar 2004 | JP | national |
Number | Name | Date | Kind |
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4522089 | Alvi | Jun 1985 | A |
4982553 | Itoh | Jan 1991 | A |
5255574 | Wuerschum | Oct 1993 | A |
5490321 | Kaneko | Feb 1996 | A |
6871566 | Niwayama et al. | Mar 2005 | B1 |
Number | Date | Country |
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5-228379 | Sep 1993 | JP |
6-324051 | Nov 1994 | JP |
2000-338111 | Dec 2000 | JP |
2003-94374 | Apr 2003 | JP |
Number | Date | Country | |
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20050210671 A1 | Sep 2005 | US |