Abstract:
A nozzle device, comprising a nozzle body, a ball provided in the nozzle body and elastically deformable by compression, an aliquoting/dispensing tip having a barrel portion in which the nozzle body including the ball is inserted, and a ball compressing mechanism which is provided in the nozzle body, configured elastically to deform the ball by compression so that the diameter of the ball increases with the nozzle body including the ball inserted in the barrel portion of the aliquoting/dispensing tip, thereby pressing the ball airtightly against an inner peripheral surface of the barrel portion of the tip, when the tip is attached to the nozzle body, and configured to remove a compressive force from the ball so that the diameter of the ball is reduced, thereby separating the ball from the inner peripheral surface of the barrel portion of the tip, when the tip is detached from the nozzle body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-328808, filed Nov. 14, 2005, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a nozzle device for aliquoting a specimen from a test tube or some other specimen container that contains a specimen, such as blood, and dispensing the specimen into another specimen container. 
     2. Description of the Related Art 
     In a known nozzle device for aliquoting and dispensing a specimen such as blood, as is described in Jpn. Pat. Appln. KOKAI Publication No. 6-323964, for example, a nozzle portion and a dispensing tip are attached to and detached from each other with use of a balloon that can be inflated and deflated by supplying and discharging a fluid. In this aliquoting/dispensing device, a balloon is provided on the nozzle portion of a head member that is located on the distal end of a specimen supply/discharge pipe. This balloon is connected to a fluid supply/discharge pipe and configured to be inflated or deflated as the fluid is supplied or discharged. If the fluid is supplied to the balloon through the fluid supply/discharge pipe with the nozzle portion including the balloon inserted in a barrel portion at the proximal end portion of the dispensing tip, the balloon is inflated and brought intimately into contact with the inner peripheral surface of the barrel portion of the tip. If the fluid in the balloon is discharged through the fluid supply/discharge pipe, on the other hand, the balloon is deflated and separated from the inner peripheral surface of the barrel portion of the tip. Thus, the nozzle portion and the dispensing tip can be attached to and detached from each other. 
     In another known nozzle device, as is described in Jpn. Pat. Appln. KOKAI Publication No. 9-127130, for example, a nozzle portion and a dispensing tip are attached to and detached from each other with use of an elastic bag capable of inflation and deflation. In this nozzle device, a ring-shaped elastic bag is provided on the outer periphery of the distal end portion of a nozzle body. This elastic bag has a hollow portion through which a fluid can be supplied and discharged. If the fluid is supplied to the bag through a fluid supply/discharge pipe with the nozzle body including the bag inserted in a barrel portion at the proximal end portion of the dispensing tip, the bag is inflated and brought intimately into contact with the inner peripheral surface of the barrel portion of the tip. If the fluid in the bag is discharged through the fluid supply/discharge pipe, on the other hand, the bag is deflated and separated from the inner peripheral surface of the barrel portion of the tip. Thus, the nozzle portion and the dispensing tip can be attached to and detached from each other. 
     In either of the prior art examples described above, however, the balloon is inflated or deflated by supplying or discharging the fluid so that it is pressed against or separated from the inner peripheral surface of the barrel portion of the dispensing tip, whereby the nozzle portion and the tip are attached to or detached from each other. Since an additional device is needed to supply and discharge the fluid to and from the balloon, therefore, the construction of the nozzle device is complicated. While the balloon, which should be inflated and deflated, must be thin-walled, moreover, it is easily damaged by friction as it is rubbed against the inner peripheral surface of the barrel portion of the dispensing tip. Thus, the balloon requires frequent maintenance including replacement. 
     BRIEF SUMMARY OF THE INVENTION 
     An aspect of the invention is; a nozzle device comprising: a nozzle body having a nozzle portion on a distal end portion of an aliquoting/dispensing pipe through which a specimen is aliquoted and dispensed; a ball provided in the nozzle body and elastically deformable by compression; an aliquoting/dispensing tip having a barrel portion in which the nozzle body including the ball is inserted; and a ball compressing mechanism which is provided in the nozzle body, configured elastically to deform the ball by compression so that the diameter of the ball increases with the nozzle body including the ball inserted in the barrel portion of the aliquoting/dispensing tip, thereby pressing the ball airtightly against an inner peripheral surface of the barrel portion of the tip, when the tip is attached to the nozzle body, and configured to remove a compressive force from the ball so that the diameter of the ball is reduced, thereby separating the ball from the inner peripheral surface of the tip, when the tip is detached from the nozzle body. Wherein a pair of the balls are located spaced in the axial direction of the nozzle body and are configured to be simultaneously compressed and pressed airtightly against the inner peripheral surface of the barrel portion of the aliquoting/dispensing tip. Wherein the ball is interposed between flange portions on the nozzle body and is compressed as the flange portions approach each other. Wherein the ball compressing mechanism comprises a fluid cylinder, a plunger which is advanced and retreated in the axial direction of the nozzle body by the cylinder, and flange portions which are coupled to the plunger and compress or release the ball as the plunger is advanced or retreated by the fluid cylinder. 
     According to the nozzle device of the present invention, the nozzle body and the dispensing tip can be attached and detached by elastically deforming the deformable balls, so that the construction of the device can be simplified. 
     Additional objects and 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 objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       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. 
         FIG. 1A  is a longitudinal side sectional view of a nozzle device according to a first embodiment of the invention with its balls released from compressive force; 
         FIG. 1B  is a longitudinal side sectional view of the nozzle device with its balls compressed; 
         FIG. 2  is an enlarged longitudinal side sectional view showing a section C of  FIG. 1A ; and 
         FIG. 3  is a longitudinal side sectional view of the nozzle device with an aliquoting/dispensing tip attached to its nozzle body. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of this invention will now be described with reference to the accompanying drawings. 
       FIGS. 1 to 3  show a first embodiment of the invention.  FIG. 1A  is a longitudinal side sectional view of a nozzle device with its balls released from compressive force.  FIG. 1B  is a longitudinal side sectional view of the nozzle device with its balls compressed.  FIG. 2  is an enlarged longitudinal side sectional view showing a section C of  FIG. 1A .  FIG. 3  is a longitudinal side sectional view of the nozzle device with an aliquoting/dispensing tip attached to its nozzle body. The aliquoting/dispensing tip is shown in neither of  FIGS. 1A ,  1 B and  2 . 
     As shown in  FIG. 3 , a nozzle device  1  for aliquoting and dispensing a specimen such as blood comprises a nozzle mechanism section  11 , which is supported by an ascending/descending mechanism  10  for ascent and descent in the vertical direction, and an aliquoting/dispensing tip  13  vertically supported on a rack or the like. 
     The nozzle mechanism section  11  will be described first. A support member  14  supported on the ascending/descending mechanism  10  is provided with an aliquoting/dispensing pipe  15  that is movable in the vertical direction. A proximal end portion  15 a of the pipe  15  is connected to a suction/discharge device (not shown) for aliquoting and dispensing a specimen such as blood through piping or the like. A nozzle body  12  is provided on the distal end portion of the aliquoting/dispensing pipe  15 . 
     As shown in  FIGS. 1 and 2 , the support member  14  is provided with a vertical air cylinder  20  for use as a fluid cylinder that constitutes a ball compressing mechanism  2 . A piston  22  that is fixed to the aliquoting/dispensing pipe  15  is inserted in a cylinder section  21  of the air cylinder  20 . Air supply/discharge pipes  23   a  and  23   b  are connected to upper and lower chambers, respectively, of the cylinder section  21 . The piston  22  is moved up or down by air that is supplied or discharged through the pipes  23   a  and  23   b . The piston  22  is coupled with a plunger  24  formed of a pipe that is connected directly to the aliquoting/dispensing pipe  15 . The plunger  24  projects downward through a guide member  25  that is attached to the support member  14 . 
     A connecting frame  24   a  is fixed to the lower end portion of the plunger  24 . The proximal end portion  15   a  of the aliquoting/dispensing pipe  15  is coupled and fixed to the frame  24   a . Thus, the connecting frame  24   a  and the pipe  15  can be moved up and down by the air cylinder  20 . The pipe  15  that projects downward from the connecting frame  24   a  is passed for up-and-down motion through a guide pipe  24   b  that is fixed to the support member  14 . The nozzle body  12  is provided on the lower end portion of the aliquoting/dispensing pipe  15 . More specifically, a screw portion  26  is provided on the distal end portion of the pipe  15 , and a nozzle portion  28  is fixed to the screw portion  26 . A nozzle orifice  27  is formed in the distal end of the nozzle portion  28 . The orifice  27  communicates with the suction/discharge device (not shown) for aliquoting and dispensing a specimen such as blood by means of a passage  29  of the aliquoting/dispensing pipe  15 . 
     Further, a fixed flange portion  30  having an arcuate profile is provided as a stopper on the lower end portion of the guide pipe  24   b . The flange portion  30  has a through hole  30   a  through which the aliquoting/dispensing pipe  15  can move in the axial direction. Furthermore, a cylindrical moving tube  31  is provided under the flange portion  30 . The moving tube  31  has a through hole  31   a  through which the aliquoting/dispensing pipe  15  can move in the axial direction. Movable flange portions  32  and  33  are formed integrally on the upper and lower end portions of the moving tube  31 . The upper movable flange portion  32  on the tube  31  is opposed to the fixed flange portion  30  at a distance from it. The lower movable flange portion  33  is opposed to a fixed flange portion  34 , which is integral with the nozzle portion  28 , at a distance from it. Thus, gaps are defined individually between the fixed flange portion  30  and the movable flange portion  32  and between the fixed flange portion  34  and the movable flange portion  33 . Silicone balls  35  for use as elastically deformable balls are fitted individually in these gaps. Each silicone ball  35  is a solid sphere having a through hole  35   a  through which the aliquoting/dispensing pipe  15  can move in the axial direction. When the balls  35  are compressed in the vertical direction, they are elastically deformed so that their diameters are larger than the outside diameters of the flange portions  32 ,  33  and  34 . Thus, the balls  35  are flattened in the direction of compression and deformed so that their outside diameters in planes perpendicular to the compression direction increase. If the compressive force is removed, the silicone balls  35  are restored to their original shape such that their outside diameters in the planes perpendicular to the compression direction are smaller than those of the flange portions  32 ,  33  and  34 . 
     As shown in  FIG. 3 , the aliquoting/dispensing tip  13  is a hollow cylinder of transparent plastic or glass. A taper portion  36  and a barrel portion  37  are provided on the distal and proximal end portions, respectively, of the tip  13 . The inside diameter of the barrel portion  37  is larger than each of the respective outside diameters of the movable flange portions  32  and  33 , fixed flange portion  34 , and silicone balls  35  so that the flange portions  32 ,  33  and  34  and the balls  35 , along with the nozzle portion  28 , can be inserted into the barrel portion  37 . 
     The following is a description of the operation of the nozzle device  1 . 
     If the piston  22  of the air cylinder  20  is in a neutral state, as shown in  FIG. 1A , the plunger  24  and the aliquoting/dispensing pipe  15  project downward. In this state, no pressure acts on the silicone balls  35  between the fixed flange portion  30  and the movable flange portion  32  and between the fixed flange portion  34  and the movable flange portion  33 . Therefore, the balls  35  are nearly perfectly spherical. In this state, the entire nozzle mechanism section  11  is moved by the ascending/descending mechanism  10 . The nozzle body  12  is positioned over the aliquoting/dispensing tip  13 . Then, the entire nozzle mechanism section  11  descends, whereupon the nozzle body  12  is inserted into the barrel portion  37  of the tip  13 . Thus, the movable flange portions  32  and  33 , fixed flange portion  34 , and silicone balls  35 , along with the nozzle portion  28 , are inserted into the barrel portion  37 . 
     If air is fed through the air supply/discharge pipe  23   b  into the lower chamber of the cylinder section  21  and discharged through the air supply/discharge pipe  23   a  in this state, the piston  22  ascends in the cylinder section  21 . As this is done, the plunger  24  that is integral with the piston  22  ascends. 
     As the plunger  24  ascends in this manner, the aliquoting/dispensing pipe  15  ascends through the connecting frame  24   a  on the distal end portion of the plunger  24 , and the nozzle portion  28  also ascends. Thereupon, the gap between the fixed flange portions  30  and  34  narrows. As this is done, the fixed flange portion  30  and the movable flange portion  32  approach each other, and the fixed flange portion  34  and the movable flange portion  33  approach each other. Thereupon, as shown in  FIG. 1B , the silicone balls  35  are vertically compressed to be elastically deformed so that their outside diameters in a plane perpendicular to the compressing direction are larger than those of the movable flange portions  32  and  33  and the fixed flange portion  34 . 
     If the silicone balls  35  are elastically deformed and increased in diameter, they come intimately into contact with the inner peripheral surface of the barrel portion  37  of the aliquoting/dispensing tip  13 , as shown in  FIG. 3 . Thereupon, the nozzle body  12  and the tip  13  are connected airtightly. 
     Then, the nozzle body  12  and the aliquoting/dispensing tip  13  are moved in an integrated manner by the ascending/descending mechanism  10  and inserted into a test tube (not shown). If suction is performed by the suction/discharge device in this state, the pressure in the tip  13  is made negative by the aliquoting/dispensing pipe  15 , so that a serum in the test tube is aliquoted into the tip  13 . 
     If the ascending/descending mechanism  10  moves again so that the nozzle body  12  and the aliquoting/dispensing tip  13  ascend in an integrated manner, the tip  13  gets out of the test tube. Then, the nozzle body  12  and the tip  13  that contain the aliquoted serum are positioned in another test tube or the like. If discharge is performed by the suction/discharge device in this state, the pressure in the tip  13  is made positive by the aliquoting/dispensing pipe  15 , so that the serum in the tip  13  is dispensed into test tubes or the like. 
     After the aliquoting and dispensing operation is finished, air is fed through the air supply/discharge pipe  23   a  into the upper chamber of the cylinder section  21  and discharged through the air supply/discharge pipe  23   b . Thereupon, the piston  22  descends in the cylinder section  21 . As this is done, the plunger  24  that is integral with the piston  22  descends. 
     If the nozzle portion  28  on the distal end portion of the aliquoting/dispensing pipe  15  descends as the plunger  24  descends, the gap between the fixed flange portions  30  and  34  widens. In other words, the fixed flange portions  30  and  34  move away from the movable flange portions  32  and  33 , respectively. As this is done, the compressive force of the silicone balls  35  that are interposed between the flange portions  30  and  32  and between the flange portions  34  and  33  is removed. Thereupon, the balls  35  are reduced in diameter. Thus, the balls  35  are restored to their original shape such that their outside diameters in the planes perpendicular to the axial direction or the compression direction are smaller than those of the flange portions  32 ,  33  and  34 . 
     If the silicone balls  35  are reduced in diameter, they are separated from the inner peripheral surface of the barrel portion  37  of the aliquoting/dispensing tip  13 . Thus, the nozzle body  12  and the aliquoting/dispensing tip  13  are disconnected and separated from each other. 
     According to the nozzle device  1  of the present embodiment, the nozzle body and the dispensing tip can be attached and detached by elastically deforming the deformable balls, so that the construction of the device can be simplified. Unlike a balloon that should be inflated and deflated, the balls need not be reduced in wall thickness, so that their reliability can be ensured. Thus, the labor of maintenance can be reduced. 
     The present invention is not limited to the embodiment described above, and its components may be embodied in modified forms without departing from the scope or spirit of the invention. In the foregoing embodiment, for example, the ball compressing mechanism  2  is constructed so that the silicone balls are compressed and released by vertically moving the plunger by means of the fluid cylinder or the like. However, the fluid cylinder may be replaced with an actuator, such as a motor-driven rack-and-pinion mechanism or a solenoid. Although the two silicone balls  35  are used in the foregoing embodiment, they may be replaced with plastic balls, and their number is not limited to two. 
     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 inventive concept as defined by the appended claims and their equivalents.