Abstract:
A manual breast pump which can be handled conveniently and disassembled with ease for cleaning or other purposes although it would not be disassembled by error in operation. The manual breast pump can include a conical suction portion, which is made to abut a breast and includes a breast pump main body that is held in communication with a bottle, and a lever with long shape in a direction and detachably fitted to the breast pump main body at a middle position thereof by means of a rotative and supportive shaft. The lever is adapted to turn in opposite directions around the shaft. The lever is operated so as to relatively reciprocate a piston and generate negative pressure so that the suction portion that is held in communication with an internal space of the lever sucks milk and causes the sucked milk to fall into the bottle.

Description:
[0001]     This application is a continuation of and claims priority under 35 U.S.C. §120 to PCT/JP2003/001223 filed on Feb. 6, 2003 in Japan designating the U.S., and claims priority under 35 U.S.C. §119 to JP2002-251463 filed on Aug. 29, 2003 to which PCT/JP2003/001223 claims priority, both of which are hereby incorporated by reference. 
     
    
     1. FIELD OF THE INVENTION  
       [0002]     This invention relates to an improvement of a manual breast pump, for example.  
       BACKGROUND OF THE INVENTION  
       [0003]     As a manual breast pump, there is a one that was proposed by the applicant of the present patent application and illustrated in  FIG. 13  of the accompanying drawings (Jpn. Pat. Appln. Laid-Open Publication Hei. 1-190364).  
         [0004]     The manual breast pump  1  comprises a breast pump main body  5  that is provided with a suction portion  2  and can be detachably fitted to a bottle  6 . A vent pipe  3 , which may typically be a rubber pipe, extends from the breast pump main body  5 . And a negative pressure generating means  4 , which is a hollow rubber member, is fitted to the opposite end of the vent pipe  3 .  
         [0005]     The user holds the bottle  6  with one of his or her hands and fit the horn-shaped suction portion  2  to a breast at the opening thereof. As the user repeatedly grasp the negating means pressure generating means  4  with the other hand to generate negative pressure, which is transmitted to the suction portion  2  by way of the vent pipe  3  and the breast pump main body  5 , mother&#39;s milk is sucked and falls into the bottle  2 .  
         [0006]     Such a manual breast pump  1  is difficult to use because it needs to be operated by the two hands. Additionally, although the bottle  2  and the vent pipe  3  can be removed from the breast pump main body  5 , the user can dismantle neither the breast pump main body  5  that has a number of branch passages nor the negative pressure generating means  4 . So, it is difficult for the user to routinely clean the inside of the breast pump main body  5 .  
         [0007]     Thus, while the manual breast pump  1  needs to be held in a hygienically clean condition because it deals with mother&#39;s milk to be ingested by infants, it requires cumbersome maintenance operations.  
         [0008]     In view of the above identified circumstances, one of several aspects of the present invention is to provide a manual breast pump that can be easily dismantled for cleaning and other purposes, cleaned with ease and handled in a hygienically clean condition.  
       SUMMARY OF THE INVENTION  
       [0009]     According to claim  1  of the present invention, an aspect of the invention can be achieved by providing a manual breast pump comprising: 
        a breast pump main body having a substantially conical suction portion to be fitted to a breast and an attach and detach portion detachably fitted to a bottle so as to communicate with the bottle and     a lever with long shape extending in a direction and detachably held by spindle on the breast pump main body at a middle part thereof by means of a spindle holding means, being held rotatably in opposite directions around the spindle     and the lever configured to suck milk from the suction portion communicating with a predetermined internal space that contains a piston by generating negative pressure in the internal space due to change of specified internal space that contains a piston by means of a relative reciprocating motion of the piston that is caused by a movement of an end of the lever as a result of a rotary motion thereof and make the sucked mother&#39;s milk drop into the bottle and a negative pressure generating means comprising a vent passage communicating with the suction portion, a fixed piston arranged at an end of the vent passage, a sleeve arranged integrally at an end of the lever, into which the fixed piston of the breast pump main body is inserted so as to communicate with the vent passage, the inserted fixed piston being adapted to slide in the inside of the sleeve when the lever is rotated so as to generate negative pressure by rotation of the lever in the space defined by the inner surface of the sleeve and a facet of the fixed piston.        
 
         [0013]     With the configuration of claim  1  of the present invention the breast pump main body can be detachably fitted to a bottle by means of an attachable/detachable portion.  
         [0014]     The breast pump is configured to generate negative pressure by operating the lever. More specifically, negative pressure is generated either by driving the piston by means of operation of the lever or by moving the space containing the piston. In short, negative pressure is generated by causing the piston to relatively reciprocate. Additionally, unlike conventional breast pump, the milker does not involve a long vent pipe, which is cumbersome and difficult to handle for maintenance or other purpose. The lever is removed from the breast pump main body so that the lever and the breast pump main body can be cleaned separately.  
         [0015]     Furthermore, since the sleeve is integrally arranged at an end of the lever, the opening through which the fixed piston is inserted comes to be exposed when the lever is removed so that the sleeve can be cleaned with ease. In short, the space for generating negative pressure has a simple configuration and can be cleaned with ease. Additionally, the fixed piston without the sleeve becomes exposed at the breast pump main body only by removing the lever so that it can also be cleaned with ease. In other words, the mechanism for generating negative pressure becomes exposed so as to be ready for cleaning only simply when the lever is removed from the breast pump main body can be provided.  
         [0016]     Thus, according to the invention, the manual breast pump disassembled with ease for cleaning and held in a hygienically clean state.  
         [0017]     The breast pump as recited in claim  1 , claim  2  of the invention is further comprising: the spindle holding means provided a bearing portion arranged at the side of the lever and a bearing portion arranged at the side of the breast pump main body; the spindle held by shaft member inserted into the spindle holes penetrated by each bearing portion laid one on the other; and the spindle member provided with an engaging means for engagement with any of the bearing sections.  
         [0018]     With the configuration of claim  2  of the invention, the lever is held by spindle to the breast pump main body by the spindle member inserted into the spindle holes so that the breast pump can be assembled with ease and disassembled only by pulling the spindle member out of the spindle holes. In short, the breast pump can be assembled and disassembled with ease. Additionally, once the spindle member is inserted into the spindle holes, the lever can no longer be removed from the breast pump main body. Thus, while the lever can be easily fitted to and removed from the breast pump main body, it is effectually prevented from inadvertently coming off from the breast pump main body. Furthermore, once the spindle member is surely engaged in position, the lever is also effectually prevented from inadvertently coming off from the breast pump main body.  
         [0019]     The breast pump as recited in claim  1  or  2 , claim  3  of the invention is further comprising: at least the inner wall of the sleeve has a curved profile that agrees with the locus of the rotary motion of an end of the lever.  
         [0020]     With configuration of claim  3  of the invention, lever can be turned easily and smoothly because its profile agrees with the locus of the rotary motion of an end of the lever.  
         [0021]     The breast pump as recited in claim  1 ,  2  or  3 , claim  4  of the invention is further comprising: the outer periphery of the piston to be elastic and to be inclined toward the lever to reduce its dimensions.  
         [0022]     With the configuration of claim  4  of the invention, the piston and the sleeve can be airtightly put together to reliably generate negative pressure in the inside because the outer periphery of the piston is elastic. Additionally, the piston contacts the sleeve at the outermost periphery thereof due to the inclination so that the lever can be operated easily.  
         [0023]     The breast pump recited in claim  1 ,  2 ,  3  or  4 , claim  5  of the invention is further comprising: The piston no longer airtightly be contacted to the inner wall of the sleeve at the end of the sleeve. When the other end of the lever be moved to come closer to the bottle.  
         [0024]     With the configuration of claim  5  of the invention, once the other end of the lever is made to come closer to the bottle to increase the negative pressure, air is allowed to leak into the inside so that the negative pressure is prevented from increasing excessively each time the lever is operated. Thus, the resistance against the operation of the lever can be prevented from becoming too large and can be prevented from an obstruction of may be operated smooth operation. At the same time, the negative pressure is made to fall quickly without difficulty. In other words, the negative pressure is made to change pulsatively.  
         [0025]     The breast pump as recited in claim  1 ,  2 ,  3 ,  4  or  5 , claim  6  of the invention is further comprising: the sleeve provided on the outer surface of its closed end with a pressure regulating means.  
         [0026]     With the configuration of claim  6  of the invention, the pressure regulating means is exposed to the outside at a position where it can be operated with ease for the convenience of the operator. Additionally, the pressure regulating means is located at a position that allows it to be removed and cleaned with ease.  
         [0027]     The breast pump recited in claim  6 , claim  7  of the invention is further comprising: the pressure regulating means arranged on the outer surface of the closed end of the sleeve; a valve box having at least two pairs of oppositely disposed inner walls, the distance L1 separating one of the pairs of oppositely disposed inner walls being greater than the distance L2 separating the other pair of oppositely disposed inner walls; a valve made of an elastic material and having a substantially circular outer periphery and a slit for allowing air to pass through; and the opening of the slit being adjusted by inserting the valve in the valve box and rotating the valve in the valve box.  
         [0028]     With the configuration of claim  7  of the invention, the pressure regulating means can be operated in a simple manner of rotating or turning the valve in the valve box. Additionally, the pressure regulating means is formed by using a minimal number of components including a valve box arranged on the outer surface of the sleeve and a valve so that it can be disassembled and cleaned with ease simply by taking out the valve out of the valve box. 
     
    
     BRIEF EXPLANATION OF THE DRAWINGS  
       [0029]      FIG. 1  is a schematic perspective view of the first embodiment of breast pump according to the invention.  
         [0030]      FIG. 2  is a schematic cross sectional view of the embodiment of breast pump of  FIG. 1 .  
         [0031]      FIG. 3  is a schematic partial cross sectional view of the embodiment of breast pump of  FIG. 1 , illustrating the structure of the spindle holding for securing the lever to the breast pump.  
         [0032]      FIG. 4  is a schematic illustration of the embodiment of breast pump of  FIG. 1 , illustrating the structure of the engagement the spindle holding.  
         [0033]      FIG. 5  is a schematic lateral view of the embodiment of breast pump of  FIG. 1 .  
         [0034]      FIG. 6  is a schematic cross sectional view of the embodiment of breast pump of  FIG. 1  when the embodiment is operated for sucking milk.  
         [0035]      FIG. 7  is a schematic cross sectional view of the embodiment of breast pump of  FIG. 1  when the embodiment is operated for leaking air.  
         [0036]      FIG. 8  is a schematic perspective view of the valve main body of the pressure regulating means arranged on the outer surface of the sleeve of the embodiment of breast pump of  FIG. 1 , the valve main body being part of the valve structure.  
         [0037]      FIG. 9  is a schematic perspective view of the valve box that is combined with the valve main body, which is part of the valve structure, to form the pressure regulating means that is arranged on the outer surface of the sleeve of the embodiment of breast pump of  FIG. 1 .  
         [0038]      FIG. 10  is a schematic illustration of operation of the pressure regulating means that is arranged on the outer surface of the sleeve of the embodiment of breast pump of  FIG. 1 .  
         [0039]      FIG. 11  is another schematic illustration of operation of the pressure regulating means that is arranged on the outer surface of the sleeve of the embodiment of breast pump of  FIG. 1 .  
         [0040]      FIG. 12  is still another schematic illustration of operation of the pressure regulating means that is arranged on the outer surface of the sleeve of the embodiment of breast pump of  FIG. 1 .  
         [0041]      FIG. 13  is a schematic illustration of a conventional breast pump.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0042]     Now, preferred embodiments of the present invention will be described in detail by referring to the accompanying drawings.  
         [0043]     The following embodiments include various preferable technical limitations because they are preferred concrete embodiments of invention. However, the scope of the present invention is not limited to them.  
         [0044]      FIG. 1  is a schematic perspective view of an embodiment of breast pump  20  according to the invention, illustrating its overall configuration.  FIG. 2  is a schematic cross sectional view of the embodiment. As shown in  FIGS. 1 and 2 , the breast pump  20  comprises a breast pump main body  21  (to be referred to simply as “main body” hereinafter) and a lever  30  (to be also referred to as “handle”), of which the lever  30  can be attach and detach to the breast pump main body  21 .  
         [0045]     The main body  21  is made of a synthetic resin material that is relatively light, tough and easily moldable. Synthetic resin materials that can be used for the main body  21  include polycarbonate, polycycloolefin and polyethersulfone and the like. The main body  21  comprises an attach and detach portion  25  to attach and detach to a bottle  41  for storing sucked milk. As shown in  FIG. 2 , the attached detach portion  25  has a flat and cylindrical profile and is typically provided with an internal thread  25   a  so that it may be engaged with the external thread formed around the neck of the bottle  41 . The bottle  41  may be one that is dedicated to the breast pump  20  or any other one that can be engaged with the attach and detach portion  25 .  
         [0046]     A conical or horn-shaped suction portion  22  inclined with its opening facing the outside are arranged at the upper portion of the attach and detach portion  25  of the main body  21 . A buffer  28  made of an elastic material such as silicon, elastomer or natural rubber is detachably fitted to the suction portion  22  at a position close to the open end of the suction portion. The buffer  28  portion reduces the stimulus given to the breast touched by suction portion  22  during the milking operation so that the breast may be free from pain. The buffer  28  portion has on the inner peripheral surface thereof a number of projections  28   a . The suction portion  22  has vent passage  22   a , which allows both air and sucked milk to pass through it and is bent downward and directed toward the bottle  41 . The opening and its periphery of the suction portion vent passage  22   a  of the suction portion  22  are located inside the main body  21  and the attach and detach portion, fit with a cellular valve  26 . Another vent passage  27  is provided adjacent to the suction portion vent passage  22   a . As shown in  FIG. 2 , the bottom end opening of the vent passage  27  is communicating with the suction portion vent passage  22   a  within the cell  26   a  of the cellular valve  26  and the vent passage  27  runs upward through piston rod  24  and terminates at the top end opening. The lower end of the suction portion vent passage is lengthened than the lower end of the vent passage  27  so that sucked milk can hardly enter the vent passage  27 .  
         [0047]     As seen in  FIGS. 1 and 2 , the cellular valve  26  has a cap-like profile as a whole and is made of an elastic material such as silicon, elastomer or natural rubber. The oppositely disposed elastic lateral walls  26   b ,  26   c  of the cellular valve  26  are inclined so as to come closer to each other as they approach the lower ends thereof. Slit  26   d  is constructed at the bottom end where both wall  26   b  and  26   c  come closely. Thus, when the volume of sucked milk stored in the cell  26   a  gets to a predetermined amount, the weight on the change of the negative pressure when negative pressure released as described later make leading edge of the lateral walls  26   b ,  26   c  open to allow milk to fall into the bottle  41 . Due to the slit  26   d  constructed at the lower ends of the inclined lateral walls, the cell  26   a  is preventing from air coming into from the bottle  41  when negative pressure prevails in the inside.  
         [0048]     The main body  21  has a fixed piston  23  that is arranged at the top of and integral with the above described piston rod  24 . While both the piston and the piston rod are stationary in this embodiment, the piston may be movable. The fixed piston  23  is arranged transversally at the top of the piston rod  24  in a direction opposite to the direction in which the suction portion  22  extends. The fixed piston  23  has a disk-shaped or an elliptic profile.  
         [0049]     In  FIG. 2 , the lever  30  has a shape prolonged approximately upward and downward and is provided at an end thereof, or the top end in  FIG. 2 , with a sleeve  32 , which is integral with the lever  30  and has an opening facing the above described fixed piston  23 . The lever  30  is a molded product and as a whole made of relatively lightweight synthetic resin such as polycarbonate, polycycloolefin or polyethersulfone.  
         [0050]     The other end of the lever  30  has a handle-like profile which extends downward as shown in  FIG. 2  to form a lever main body  31  as operating part.  
         [0051]     The lever  30  can be attached and detached to the main body  21  in a manner as will be described hereinafter. When the lever  30  is fixed to its position, it is secured to the main body  21  at a longitudinal middle position thereof by means of a spindle holding so that it may be rotate or turned or swinged around the spindle in two opposite directions, or the directions of arrows A 1  and B  1  in  FIG. 2  or arrows A 2  and B 2  in  FIG. 6 .  
         [0052]     An oblong leaf spring  33  or the like is arranged as urging means in the inside of the lever  30 . The leaf spring  33  is bent along an edge thereof and the bent section of the leaf spring  33  is secured in position as it is pinched by a holding means  21   b  fitted to the main body  21 , while the opposite edge of the leaf spring  33  is secured in position as it is made to abut a spring bearing  34  of which other end arranged near the front end of the lever main body  31  of the lever  30 . With this arrangement, the lever main body  31  of the lever  30  is urged by the leaf spring  33  in the direction of arrow B 2 .  
         [0053]     The sleeve  32  integrally arranged at an end of the lever  30 , or at the top end in  FIG. 2 , has a closed end portion of which end edge portion  32   b  is closed. And location of the fixed piston  23  is an opening  32   a . The wall portion  32   c  surrounding the opening  32   a  defines cylinder-shaped internal spaces S 1 , S 2  that are open only at an end. While the internal spaces S 1 , S 2  is a single space, the single space is divided into an open space S 2  that is open to the atmosphere and a closed space S 1  that is defined by the (inner) wall section  32   c  and the inside of the end section  32   b  of the sleeve  32  when the fixed piston  23  is inserted into the sleeve  32  through the opening  32   a.    
         [0054]     A pressure regulating means  37  is fitted to the outer surface of the closed end section  32   b  which is the closed end of the sleeve  32  so as to make the pressure of the internal space S 1  adjustable. A number of projections may be arranged on the inner wall of the closed end section  32   b  of the sleeve  32  to such a height that they may not hit the piston  23  for the purpose of reducing the volume of air in the internal space S 1  and boosting the negative pressure in the inside when the breast pump is in operation. At least the inner wall  32   d  of the sleeve  32  is made to show a profile that substantially agree with the locus of the rotary motion of the top end and that of the bottom end of the lever  30 . Thus, the sleeve  32  shows a profile that substantially agree with the locus of the rotary motion of the top end and that of the bottom end of the lever  30 , the lever  30  can be moved to rotate smoothly and easily.  
         [0055]     On the other hand, the fixed piston  23  arranged at the side of the main body  21  has a profile that allows the piston to tightly contact the inner wall of the sleeve  32  and a ring-shaped packing  23   a  that is an elastic member and operates as piston ring is fitted to the flange-shaped end of the fixed piston. At least a part  23   b  of the outer periphery of the packing  23   a  is inclined toward the lever  30  (left side in  FIG. 2 ) so as to reduce its dimensions. Due to the inclination, as the outermost periphery of the elastic packing  23   a  abuts the entire periphery of the inner wall  23   d , the airtight closure is maintained and the lever  30  can be operated lightly.  
         [0056]     As shown in  FIG. 1 , the wall of the sleeve  32  of the lever  30  is partly indented at a position near the top end of the sleeve  32  to produce a leak section  38 . This section is located at the end of the sleeve  32  in terms of the relative reciprocating motion of the fixed piston  23 , which will be described hereinafter. This portion functions in a state when negative pressure is maximized.  
         [0057]     Thus, for an operation of breaking negative pressure, being partly opened to the atmosphere by way of the leak section  38  by only the fixed piston  23  being moved to the leak section  38  so that the lever  30  can be operated easily without exerting extremely large force. It may be so arranged that the entire peripheral edge of the fixed piston  23  or an upper region thereof simultaneously comes out of the sleeve  32  for an operation of breaking negative pressure.  
         [0058]     As will be described hereinafter, any increase of negative pressure can be rapidly reduced to smoothly and pulsatively change negative pressure by allowing air to leak after the lever main body  31  is moved toward the bottle  41  to consequently increase negative pressure.  
         [0059]     Now, the arrangement of securing the lever  30  to the main body  21  by means of a spindle holding will be described by referring to  FIGS. 3 and 4 .  
         [0060]      FIG. 3  shows an example of a structure that can be used to rigidly secure the lever  30  of the breast pump  20  to the attach and detach portion  25 .  
         [0061]     The attach and detach portion  25  is provided as integral portion thereof with a pair of bearing portions  85 ,  85  for the main body  21 . On the other hand, the lever  30  is provided with a pair of bearing portions  75 ,  75  that are located outside of the width between bearing portions  85  and  85 .  
         [0062]     An oblong spindle member  81  is provided with a base portion  72  and a projection or ridge  74 . The spindle member  81  has a spindle  83  that is inserted in such a way it penetrate the lever side bearings  75 ,  75  and the attach and detach portion side bearings  85 ,  85 . A holding pawl  74   a  is arranged at the front end of the projection or ridge  74  in order to prevent the spindle member  81  from inadvertently coming off from the bearing portion.  
         [0063]     As shown in  FIG. 4 , the bearing portion  75  of the lever  30  is provided with a sloped surface  75   a  and a horizontal engaging surface  75   b  continued to the sloped surface  75   a  at a lower portion of the bearing portion  75 .  
         [0064]     Then, the bearing portion  75  of the lever  30  is placed on the corresponding bearing portion (not shown) of the main body  21  and the spindle  83  of the spindle member  81  is driven to run through the spindle holes  76 ,  76  of the bearing portions  75  from the both outside of each bearing portion  75 .  
         [0065]     As showing in  FIG. 4 , firstly, the spindle member  81  is inclined. Then, as the spindle  83  is driven to run through the spindle holes  76  and the spindle member  81  is rotated around the spindle  83  in the direction of arrow E 1 , the projection  74  comes to be engaged with or held by the horizontal engaging surface  75   b.    
         [0066]     As a result, the lever  30  is secured to the main body  21 .  
         [0067]     Conversely, to remove the lever  30  from the main body  21 , the spindle member  81  is rotated in the direction of arrow E 2  in  FIG. 4 . Then, the projection  74  is released from the horizontal engaging surface  75   b . As a result, the lever  30  can be removed from the main body  21 .  
         [0068]     In this way, the lever  30  is securely held only by the spindle member  81  be inserted into the spindle holes  76  and by the operation for mutual engagement. Therefore, the assembling operation is very simple and easy. Additionally, the lever  30  can be removed from the main body  21  simply by removing the spindle member  81  from the spindle holes  76  so that assembling and disassembling is easy. However, the lever cannot be removed from the main body  21  when the spindle member  81  is inserted by and engaged with the bearing portion  75 . In short, while the lever  30  can be easily fitted to and removed from the main body  21 , it is effectively prevented from inadvertently coming off from the main body  21 .  
         [0069]      FIG. 2  shows that the embodiment of breast pump  20  having the above described configuration in an unused or mint state. It is operated in a manner as described below.  
         [0070]     Referring to  FIG. 2 , the lever  30  is fitted to the main body  21  and the bottle  41  is fitted to the main body  21  by way of the attach and detach portion  25 .  
         [0071]     Under this condition, the sleeve  32  of the lever  30  has been moved in the direction of arrow A 2  by the leaf spring  33  so that the fixed piston  23  is located deep in the inside of the sleeve  32 .  
         [0072]     Then, the user applies the suction portion  22  to the breast by way of the opening thereof so that the breast may be surrounded by the suction portion  22 . Then, the user applies the thumb of one of his or her hands to the bottle  41  and all or some of the fingers of the hand to the lever main body  31  of the lever  30  (not shown). Under this condition, the user closes the hand to operate the lever main body  31 . Then, the lever  30  turns around the spindle in the direction of arrow A 1  and also in the direction of arrow B 1  as shown in  FIG. 1  against the urging force of the leaf spring  33 . During this process, the fixed piston  23  is moved relatively in the direction of arrow D to increase the volume of the internal space S 1  of the sleeve  32 . As a result, the negative pressure in the inside of the internal space S 1  of the sleeve  32  is increased and the increased negative pressure is made to propagate to the suction portion vent passage  22   a  by way of the vent passage  27  and the cell  26   a . Thus, negative pressure prevails in the inside of the suction portion  22  to suck mother&#39;s milk from the breast and the sucked mother&#39;s milk is driven to pass through the suction portion vent passage  22   a  and stored in the cell  26   a . At this time, by convex portion  28   a  of the buffer  28  arranged in the inside of the suction portion  22 , the breast drawn by the negative pressure in the inside of the suction portion  22  so as to abut, is pressed and provided an effect similar to that of massage.  
         [0073]     At this time, since negative pressure prevails in the inside of the cell  26   a , the oppositely disposed lateral walls  26   b ,  26   c  of the cellular valve  26  are drawn upward to close the slit  26   d.    
         [0074]     Then, as the user grasps the lever main body  31  in the direction of arrow BB until it comes to abut the outer edge of the bottle  41 , the fixed piston  23  is moved relatively in the direction of arrow D. Eventually, the fixed piston  23  comes to the end of the relative movement and air infiltrates into the internal space S 1  of the sleeve  32  through the leak portion  38 . As a result, the negative pressure in the internal space S 1  is quickly reduced and the internal pressure of the cell  26   a  that is held in communication with the internal space S 1  by way of the vent passage  27  also comes close to the atmospheric pressure to decrease the effect of drawing the oppositely disposed lateral walls  26   b ,  26   c  of the cellular valve  26  upward. Then, the slit  26   d  constructed at the lower ends of the lateral walls  26   b ,  26   c  is opened by the weight of the mother&#39;s milk stored in the cell  26   a  and the milk stored in the cell  26   a  falls into the inside portion S 3  of the bottle  41 .  
         [0075]     As a result of this process, the sucking pressure of the suction portion  22  applied to the breast of user falls.  
         [0076]     Then, the lever  30  is returned to the position shown in  FIG. 2  by the urging force of the leaf spring  33 . Thus, operation of sucking milk can be continued by the user repeating the above process.  
         [0077]     Therefore, with the embodiment of breast pump  20  according to the invention, the user is not required to handle the breast pump with his or her two hands unlike the conventional breast pump described above by referring to  FIG. 3 . So, the user only needs to use his or her dominant hand to handle the breast pump  20 . Thus, the operation is simple and easy.  
         [0078]     Additionally, the embodiment of breast pump  20  does not involve the use of a conventional long air pipe and the like, which is cumbersome and difficult to handle. So, the embodiment of breast pump  20  is remarkably superior in storage and portability.  
         [0079]     As described above and illustrated in  FIGS. 2, 6  and  7 , once the lever  30  is fitted to the main body  21 , engagement of spindle holding structure of the lever  30  with the main body  21  is not detached any changeful position in the state that the bottle  41  is fitted to the main body  21 . In other words, once the lever  30  is fitted to the main body  21 , the status that main body  21  is fitted to the bottle  41 , the situation is that the user can proceed under the operation of sucking milk, the lever is constructed not to come off from the main body  21 .  
         [0080]     Thus, the lever  30  is securely held to the main body  21  only by the spindle member  81  be inserted into the spindle hole  76  and by operation for mutual engagement. Therefore, the assembling is very simple and easy. Additionally, the lever  30  can be removed simply by removing the spindle member  81  from the spindle hole  76  so that the assembling and disassembling is easy. Furthermore, in the breast pump  20 , the leaf spring  33  as urging means is held at an end thereof by the holding means  21   b  of the main body  21  as shown in  FIG. 5  and made at the other end thereof to abut the spring bearing  34  arranged near the front end of the lever main body  31  of the lever  30  in a manner as described above. Therefore, when the lever  30  is removed from the main body  21 , it can be taken out simultaneously with ease and cleaned. When the urging means is a leaf spring  33  that is made of metal, stainless steel (SUS304) in particular, it is superior in durability and can surely rebound. Additionally, the leaf spring  33  can be taken out to sterilize the remaining components of the breast pump  20  by means of a chemical such as sodium hypophosphite and the like. In this case, this operation is conducted safely because the leaf spring  33  cannot be taken out without removing the lever  30  from the main body  21 .  
         [0081]     Furthermore, in the breast pump  20 , the sleeve  32  is integrally formed at an end of the lever  30 . Thus, the opening for inserting the fixed piston  23  and the sleeve  32  of which internal space are exposed can be cleaned by only removing the lever  30 , so, the space for generating negative pressure has a simple configuration and can be cleaned with ease. Additionally, once the lever  30  is removed, the fixed piston  23  from which the sleeve  32  has been moved away comes to be exposed on the main body  21  so that it can also be cleaned with ease. In this case, since the sleeve  32  is made movable while the piston is fixed, the piston rod  24  of the fixed piston  23  does not require any junction such as link. So, the piston rod  24  is free from parts where dirt of dregs and the like of mother&#39;s milk and the like would easily adhere and is difficult to remove so that it can be cleaned with ease and held in a highly hygienic condition.  
         [0082]     In short, the mechanism for generating negative pressure can be exposed for cleaning by a simple operation of removing the lever  30  from the main body  21 .  
         [0083]      FIGS. 8 through 12  illustrate the valve structure of the pressure regulating means  37  arranged on the outer surface of the sleeve  32  of the breast pump  20 .  
         [0084]      FIG. 8  shows the valve main body  85  that is part of the pressure regulating means  37  and  FIG. 9  shows the valve box portion  87  that is to be combined with the valve main body  85 .  
         [0085]     The valve box  91  of the valve box portion  87  is a bottomed cylinder having two pairs of oppositely disposed inner walls  88 ,  88  and  89 ,  89  in the inside. The pair of oppositely disposed inner walls  88 ,  88  are separated from each other by distance L1, which is greater than distance L2 by which the other pair of oppositely disposed inner walls  89 ,  89  are separated from each other. L1 is substantially equal to or slightly greater than the diameter of the circular valve body  86 . The distance L2 is smaller than the diameter of the valve body  86 .  
         [0086]     As shown in  FIG. 8 , the valve main body  85  that is housed in the valve box  91  has a valve body  86  at the front end of a substantially flat and cylindrical base  92  that is made of a hard material. The valve body  86  has a circular outer periphery and a slit  94  located at the center thereof. At least a part of the valve body  86  where the slit  94  is formed is made of an elastic material such as rubber.  
         [0087]     As for the situation that, the valve body  86  is housed in the valve case  91  shown in  FIG. 9 .  FIG. 10  is a cross sectional view of the valve body  86  and the abstract of situation of a stopper.  
         [0088]     Referring to  FIG. 10 , the stopper  86   a  projecting inward is arranged on the inner periphery of the base section  92 . On the other hand, the valve case  91  is provided at a base section thereof with a guide groove  93  for receiving the stopper  86   a . The guide groove  93  contains therein a first positioning portion  93   a  projecting outward and a second positioning section  93   b  spaced from the first positioning section  93   a  by ¼ of the circumference or more.  
         [0089]     As seen from  FIG. 10 , when the stopper  86   a  abuts the first positioning section  93   a , the valve main body  86  is housed in the valve case  91  in such a way that the slit  94  locates so as to connect the inner walls  88 ,  88 . So, the longitudinal direction of the slit  94  agrees with that of the longer distance L1 so that the slit  94  is closed. Additionally, since the distance L2 is small relative to the disk-shaped valve body  86 , the slit  94  is pushed and pressed to the direction to be pushed. Thus, the pressure regulating means  37  is closed and the inner space S 1  is isolated from the atmosphere.  
         [0090]     On the other hand, as the valve main body  86  is turned in the valve case  91  and the base portion  93  is relatively turned in the direction indicated by an arrow, the distance that contains the longitudinal direction of the slit  94  is gradually reduced and the opposite ends  94   a ,  94   a  of the slit  94  which was crushed the slit becomes open to allow air to pass through it slightly. As a result, the negative pressure in the internal space S 1  of the sleeve  32  is slightly reduced.  
         [0091]     Then, as shown in  FIG. 11 , as the valve main body  86  is turned further in the valve box  91  in the direction indicated by the arrow until the stopper  86   a  abuts the second positioning portion  93   b , the distance that contains longitudinal direction of the slit  94  is further reduced. Since the longitudinal direction of the slit  94  is in the direction of the shorter distance L2, the slit  94  becomes filly open. As a result, air passes at an enhanced rate to remarkably reduce the negative pressure in the internal space S 1  of sleeve  32 .  
         [0092]     By the way, the present invention is by no means limited to the above described embodiment.  
         [0093]     For instance, the outer surface of the lever main body of the lever  30  may be provided with anti-slippery undulations or a finger hook so that the lever  30  may be handled with ease.  
         [0094]     After the above described embodiment, or example of modification some of the components may be omitted if needed or combined with other components which is not explained herein.  
       INDUSTRIAL APPLICABILITY  
       [0095]     As described above in detail, the present invention provides a manual breast pump that can be conveniently operated by hand.