Patent Publication Number: US-9421538-B1

Title: Pipette

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a pipette, and especially relates to a pipette for washing a reaction tube. 
     2. Description of the Prior Art 
     Current automation of washing reaction tubes usually is performed through a work platform equipped with two sliding arms, each of which has an XY positioning mechanism and a Z positioning mechanism. Therein, one of the sliding arms is equipped with an adaptor for providing washing liquid, and the other one is equipped with an adaptor for drawing waste liquid. Each adaptor is sleeved with a common pipette for providing washing liquid or drawing waste liquid. In principle, injecting of the washing liquid and drawing of the waste liquid is performed separately for requirements for without pollutions on the reaction tubes. One injection of the washing liquid and one draw of the waste liquid are taken as a washing cycle. In general, the washing for the reaction tube needs three cycles. For meeting the requirement for without pollutions, at least the adaptor for drawing the waste liquid needs to use a new pipette every cycle so that no external pollutions get into the reaction tube that contains waste liquid to be drawn. Accordingly, the washing of the reaction tube includes a plurality of movements of the sliding arms and a plurality of operations of replacing pipettes, resulting in a longer washing time and a greater consumption of pipettes. Therefore, the current washing mechanism for reaction tubes can hardly reduce time cost and consumables cost. 
     SUMMARY OF THE INVENTION 
     An objective of the invention is to provide a pipette, which provides two paths through a single member. When the pipette is used in a washing process for a reaction tube, washing liquid and waste liquid can be injected and drawn respectively simultaneously, so that the movement time of the sliding arms and the replacement cost of the pipettes can be reduced. 
     A pipette according to the invention includes a pipe. The pipe includes a connection end portion, an inner flow passage, and an outer flow passage surrounding an inner flow passage. The inner flow passage has a first opening portion and a second opening portion opposite to the first opening portion. The outer flow passage has a third opening portion and a fourth opening portion opposite to the third opening portion. The first opening portion and the third opening portion are disposed at the connection end portion. The second opening portion and the fourth opening portion are disposed at an interval. Thereby, the pipette according to the invention can provide two flowing paths through a single member. Furthermore, the second opening portion and the fourth opening portion are separate, so that the two flowing paths will not interfere with each other. When used in a washing process for a reaction tube, the pipette is coupled through the connection end portion with an adaptor capable of providing washing liquid and drawing waste liquid. Then, a plurality of washing cycles can be performed by inserting the pipette into the reaction tube once. Compared with the prior art, for a washing process for one reaction tube (including three washing cycles), the pipette according to the invention just need one 
     Compared with the prior art, just one pipette according to the invention is needed for a washing process for a reaction tube (i.e. including three washing cycles), so the consumables cost is reduced. Besides, the time cost is also reduced due to no need to change the pipette during the washing process. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a pipette of an embodiment according to the invention. 
         FIG. 2  is a top view of the pipette in  FIG. 1 . 
         FIG. 3  is a sectional view of the pipette in  FIG. 2  along the line X-X. 
         FIG. 4  is a sectional view of the pipette in  FIG. 2  along the line Y-Y. 
         FIG. 5  is a sectional view of the pipette in  FIG. 1  applied to an adaptor. 
         FIG. 6  is a sectional view of the pipette in  FIG. 1  inserted into a reaction tube. 
         FIG. 7  is a sectional view of a pipette of another embodiment according to the invention. 
         FIG. 8  is a sectional view of a pipette of another embodiment according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Please refer to  FIGS. 1-5 .  FIG. 1  is a schematic diagram illustrating a pipette  1  of an embodiment according to the invention.  FIG. 2  is a top view of the pipette  1 .  FIG. 3  is a sectional view of the pipette  1  along the line X-X in  FIG. 2 .  FIG. 4  is another sectional view of the pipette  1  along the line Y-Y in  FIG. 2 .  FIG. 5  is a sectional view of the pipette  1  that is applied to an adaptor  2 . The pipette  1  includes a pipe  10 . The pipe  10  includes a connection end portion  102 , an inner flow passage  104  and an outer flow passage  106  surrounding the inner flow passage  104 . The inner flow passage  104  has a first opening portion  1042  and a second opening portion  1044  opposite to the first opening portion  1042 . The outer flow passage  106  has a third opening portion  1062  and a fourth opening portion  1064  opposite to the third opening portion  1062 . The first opening portion  1042  and the third opening portion  1062  are disposed at the connection end portion  102 . The second opening portion  1044  and the fourth opening portion  1064  are disposed at an interval L 1 . The adaptor  2  has a waste liquid inlet  22   a , a waste liquid outlet  22   b  connected to the waste liquid inlet  22   a , a washing liquid inlet  24   a , and a washing liquid outlet  24   b  connected to the washing liquid inlet  24   a . When in use, the pipette  1  is coupled with the adaptor  2  through the connection end portion  102 , so that the first opening portion  1042  of the inner flow passage  104  is coupled with the waste liquid inlet  22   a  and the third opening portion  1062  of the outer flow passage  106  is coupled with the washing liquid outlet  24   b . Thereby, the inner flow passage  104  is connected to a waste liquid channel  22  inside the adaptor  2 , and the outer flow passage  106  is connected to a washing liquid channel  24  inside the adaptor  2 . Therein, the determination of the interval L 1  depends on the use condition of an applied case (e.g. washing a reaction tube). In general, the interval L 1  is shorter than the depth of the reaction tube. For example, for different application cases, the interval L 1  can be within a range from 5 mm to 100 mm. 
     Furthermore, each of the inner flow passage  104  and the outer flow passage  106  forms a flowing path. In coordination with the flowing paths of the adaptor  2 , the flowing path (indicated by solid arrows in the sectional views) of the inner flow passage  104  is located at the central portion of the pipe  10  while the flowing path (indicated by hollow arrows in the sectional views) of the outer flow passage  106  is located at the peripheral portion of the pipe  10 . By the staggered disposition of the second opening portion  1044  and the fourth opening portion  1064 , interference between the two flowing paths can be greatly reduced. Please also refer to  FIG. 6 .  FIG. 6  is a sectional view of the pipette  1  inserted into a reaction tube  3 . When the pipette  1  is in use, the washing liquid passes through the washing liquid inlet  24   a , the washing liquid channel  24 , the washing liquid outlet  24   b , the third opening portion  1062 , the outer flow passage  106 , and the fourth opening portion  1064  to get in the reaction tube  3 ; the waste liquid (including liquid originally existing inside the reaction tube  3  and the washing liquid having entered the reaction tube  3 ) passes through the second opening portion  1044 , the inner flow passage  104 , the first opening portion  1042 , the waste liquid inlet  22   a , the waste liquid channel  22 , and the waste liquid outlet  22   b  to be retrieved. In the embodiment, in coordination with the usage condition that the inner flow passage  104  connects with the waste liquid channel  22 , the second opening portion  1044  protrudes out of the fourth opening portion  1064 ; i.e. in the view point of  FIG. 6 , the second opening portion  1044  is located relatively low. This configuration is conducive to an efficient retrieval of the waste liquid (including liquid originally existing inside the reaction tube  3  and the washing liquid having entered the reaction tube  3  from the fourth opening portion  1064 ). However, the invention is not limited thereto. 
     Furthermore, in the embodiment, the pipe  10  is a coaxial structure, so the outer flow passage  106  shows a hollow cylinder. The outer flow passage  106  has an extending direction D 1  (indicated by a solid line segment with an arrow) at fourth opening portion  1064 . The fourth opening portion  1064  includes a plurality of holes  1064   a  disposed outwards relative to the extending direction D 1 , so that the washing liquid substantially radially flows out the outer flow passage  106  from the holes  1064   a  relative to the extending direction D 1  and flows down along the inner sidewall of the reaction tube  3 . Furthermore, in the embodiment, the holes  1064   a  are disposed at the periphery at equal central angular intervals relative to the extending direction D 1 , which facilitates the washing liquid flowing in the reaction tube  3  uniformly and enhances the washing effect to the reaction tube  3 . 
     Furthermore, in the embodiment, the outer flow passage  106  has an outer sidewall surface  106   a  and an outer end wall surface  106   b  connected to the outer sidewall surface  106   a . The outer end wall surface  106   b  is a concave conical surface. The holes  1064   a  are located on the outer sidewall surface  106   a  close to the outer end wall surface  106   b . By the design of the concave conical surface, if liquid spatters from the lower toward the fourth opening portion  1064 , the liquid can be blocked by the outer end wall surface  106   b ; besides, by the effect of the geometric shape of the outer end wall surface  106   b  (i.e. the outer end wall surface  106   b  and the outer sidewall surface  106   a  connecting with each other to form an acute angle  106   c ), when the gravity of liquid adhering onto the outer end wall surface  106   b  increases, the liquid will flows to the edge (i.e. where the outer sidewall surface  106   a  and the outer end wall surface  106   b ) of the outer end wall surface  106   b  and drops, without spreading upward to the fourth opening portion  1064  to pollute the washing liquid. In practice, with a consideration to the adhesive force between the washing liquid and the outer sidewall surface  106   a , the holes  1064   a  can be disposed a little away from the connection of the outer sidewall surface  106   a  with the outer end wall surface  106   b , for further reducing the possibility that the liquid that has reached the edge of the outer end wall surface  106   b  pollutes the washing liquid. In addition, in the embodiment, the outer flow passage  106  has an inner end wall surface  106   d  opposite to the outer end wall surface  106   b . The inner end wall surface  106   d  also shows a conical structure to provide a slanting surface relative to the extending direction D 1  for the washing liquid that passes through the fourth opening portion  1064 , so that after the liquid flowing out from the fourth opening portion  1064 , a force of the liquid hitting the inner sidewall of the reaction tube  3  can be reduced so that the washing liquid can flow downward along the inner sidewall of the reaction tube  3  more smoothly. However, the invention is not limited thereto; for example, the inner end wall surface  106   d  is perpendicular to the extending direction D 1 . 
     It is added that in the embodiment, the outer end wall surface  106   b  is concave conical so as to prevent spattering liquid from polluting the washing liquid; however, the invention is not limited thereto. In principle, the washing liquid flows out of the outer flow passage  106  from the holes  1064   a , so preventing the liquid adhering on the outer end wall surface  106   b  from approaching the hole  1064   a  can efficiently reduce the pollution in the washing liquid. Thereby, in practice, it is practicable to form an acute angle where portions of the outer end wall surface  106   b  close to the holes  1064   a  is connected with the outer sidewall surface  106   a , and the other portions of the outer end wall surface  106   b  can be connected with the outer sidewall surface  106   a  in a rectangular or obtuse angle. 
     It is added more that in the embodiment, the voidance of pollution in the washing liquid induced by liquid spattering is achieved by the outer end wall surface  106   b  of the outer flow passage  106 ; however, the invention is not limited thereto. Please refer to  FIG. 7 , which is a sectional view of a pipette  4  of another embodiment according to the invention. The pipette  4  is substantially structurally equal to the pipette  1 , so the pipette  4  uses the same reference numbers as the pipette  1 . For other descriptions of the pipette  4 , please refer to the relevant descriptions of the components of the pipette  1  notated with the same reference numbers, which will not be repeated in addition. A difference between the pipette  4  and the pipette  1  is that the pipette  4  includes a block portion  42  which is disposed between the second opening portion  1044  and the fourth opening portion  1064  and also can prevent the waste liquid below spattering upwards from polluting the washing liquid from the fourth opening portion  1064 . Further, the block portion  42  has a concave conical surface  42   a  surrounding the sidewall of the inner flow passage  104  toward the second opening portion  1044 . The concave conical surface  42   a  has the same function as the concave conical outer end wall surface  106   b , which will not be repeated in addition. In another aspect, in the pipette  1 , the concave conical outer end wall surface  106   b  is equal to the block portion  42  in logic. 
     Please refer to  FIGS. 1 to 6 . In the embodiment, the connection end portion  102  includes an inner ring wall  1022  and an outer ring wall  1024  surrounding the inner ring wall  1022 . The first opening portion  1042  is formed inside the inner ring wall  1022 . The third opening portion  1062  is formed between the inner ring wall  1022  and the outer ring wall  1024 . The adaptor  2  has a protruding connection port  2   a , of which the waste liquid inlet  22   a  is located at the central portion and the washing liquid outlet  24   b  is located at the peripheral portion. When the connection end portion  102  is coupled with the adaptor  2 , the outer ring wall  1024  tightly sleeves on the connection port  2   a  of the adaptor  2  (for example with a O-ring  26  disposed therebetween), and the first opening portion  1042  tightly abuts against the waste liquid inlet  22   a  (in practice, may be by an additional structure for coupling the first opening portion  1042  with the waste liquid inlet  22   a  more tightly). Therein, the outer ring wall  1024  tightly sleeves on the connection port  2   a  and the first opening portion  1042  tightly abuts against the waste liquid inlet  22   a , so the coupling of the third opening portion  1062  with the washing liquid outlet  24   b . Furthermore, in the embodiment, the outer ring wall  1024  has a bell mouth  1024   a , which is conducive to the insertion of the connection port  2   a  into the connection end portion  102 . 
     In the above embodiments, the pipe  10  is realized by a coaxial structure, substantially consisting of an inner tube  10   a  and an outer tube  10   b  surrounding the inner tube  10   a  (or the inner tube  10   a  passing through the outer tube  10   b ). A passage formed inside the inner tube  10   a  serves as the inner flow passage  104 ; a passage formed between the outer tube  10   b  and the inner tube  10   a  (i.e. bounded by the outer surface of the inner tube  10   a  and the inner surface of the outer tube  10   b ) serves as the outer flow passage  106 . As a whole, the inner flow passage  104  and the outer flow passage  106  extend in the same axis direction that is equal to the extending direction D 1  in the embodiment. Furthermore, for enhancing the structural strength of the outer tube  10   b  and the inner tube  10   a , the pipe  10  includes a plurality of ribs  10   c - 10   d , connecting to the outer tube  10   b  and the inner tube  10   a  in different heights. The invention is, however, not limited thereto. For example, the outer tube  10   b  and the inner tube  10   a  are disposed to be eccentric, which also can form an inner flow passage substantially at the central portion and an outer flow passage surrounding the inner flow passage. For another example, a bundle of pipes is used so that in the sectional view thereof, the pipes at the central portion serve as an inner flow passage, and the pipes at the peripheral portion serve as an outer flow passage; therein, an end of the bundle forms a first opening portion of the inner flow passage and a third opening portion of the outer flow passage in a structural integration way or through an additional component, so that the end of the bundle can be coupled with the adaptor  2 . For another example, the pipe  10  can still be realized by a coaxial structure but not extends along a straight path. 
     In addition, the above embodiments are based on a condition that the second opening portion  1044  protrudes out the fourth opening portion  1064 , but the invention is not limited thereto. Please refer to  FIG. 8 , which is a sectional view of a pipette  5  of an embodiment according to the invention. The pipette  5  is substantially equal to the pipette  1  in structural logic, so the pipette  5  uses the same reference numbers as the pipette  1 . For other descriptions of the pipette  5 , please refer to the relevant descriptions of the components of the pipette  1  notated with the same reference numbers, which will not be repeated in addition. A difference between the pipette  5  and the pipette  1  is that in the pipette  5 , the fourth opening portion  1064  protrudes out the second opening portion  1044 . Therefore, in the embodiment, the inner flow passage  104  is used for the washing liquid, and the outer flow passage  106  is used for the waste liquid. In another aspect, when the pipette  5  is in use, the flowing paths of the inner flow passage  104  and the outer flow passage  106  are different to the flowing paths of the pipette  1 . Accordingly, the adaptor  2  (referring to  FIG. 5 ) is modified so that the channel  22  serves as a washing liquid channel, and the channel  24  serves as a waste liquid channel, which can be realized by washing the adaptor  2  and switching flowing paths (i.e. the flowing paths connected to the adaptor  2 ) for example. In this case, the structural connection of the connection end portion  102  of the pipette  5  with the connection port  2   a  of the adaptor  2  still can be the same as that of the pipette  1  with the adaptor  2 . In practice, it is acceptable to modify the structure design of the connection end portion  102  of the pipette  5 , so that the inner flow passage  104  of the pipette  5  still can connect with the channel  22  and the outer flow passage  106  still can connect with the channel  24 , which can avoids an operation of re-setting the channels of the adaptor  2 . 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.