Abstract:
An inlet for a pump is provided herein including a first elongated component and a tubular second elongated component disposed coaxially about the first elongated component so as to define a space therebetween. Advantageously, with the subject invention, an inlet for a pump can be provided which can be modularly formed from components. In this manner, the components can be manufactured, e.g., by molding, and assembled with a pump, thereby avoiding the difficulties associated with the manufacture and assembly of dip tubes.

Description:
BACKGROUND OF THE INVENTION 
     In most contemporary hand-operated pump dispensers, a flowable product is enclosed within a base container, and a hand operated pump or finger pump is connected to the container for dispensing the product. Typically, the pump communicates with the container through a dip tube or fluid conduit. One problem with such a design, particularly when applied to small dosage amounts, is that it requires a very narrow dip tube, which is difficult to manufacture and assemble to the pump. A dip tube is typically extruded from a pliable plastic, and, because of the small dimensions associated with the dip tube, it is often difficult to make, handle and mount to the pump mechanism. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an inlet for a pump. Although the inlet can be used in various settings, including conveying large amounts of flowable material, it is particularly well-suited to supply product in small dosage settings. 
     An inlet for a pump is provided herein including a first elongated component and a tubular second elongated component disposed coaxially about the first elongated component so as to define a space therebetween. Advantageously, with the subject invention, an inlet for a pump can be provided which can be modularly formed from components. In this manner, the components can be manufactured, e.g., by molding, and assembled with a pump, thereby avoiding the difficulties associated with the manufacture and assembly of dip tubes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic of a pump incorporating the subject invention; 
         FIG. 2  is an enlarged view of the subject invention; and 
         FIG. 3  is a cross-sectional view taken along lines  3 - 3  of  FIGS. 1 and 2 . 
     
    
    
     DETAILED DESCRIPTION 
     An inlet for a pump is described herein in accordance with present invention. The disclosed inlet is for delivering liquid, gels, slurries, and other flowable materials to a pump. It is particularly well-suited for conveying small doses of flowable material to a pump. Advantageously, the inlet can be used for ophthalmic pump applications, where small doses may be desired. 
     With reference to  FIG. 1 , a pump  10  is depicted, which can be of various configurations. For illustrative purposes, the pump  10  is depicted with a specific configuration. 
     As will be recognized by those skilled in the art, other pump configurations are usable in connection with the subject invention. The pump  10  can be of any known design requiring an inlet for a flowable material. The pump  10  includes a pump body  11  defining a fluid reservoir  12  to accommodate a select flowable material. The reservoir  12  is at least partially bounded by an inner wall  14  and a base  16 . The reservoir  12  can be adapted with various configurations and to contain various amounts of flowable material. 
     As shown in  FIG. 1 , with the reservoir  12  handling a relatively small capacity, an engagement wall  18  may be provided, sized and shaped to be comfortably handled by a user. The engagement wall  18  is formed to encircle the inner wall  14  in defining a gripping surface. Preferably, a resting base  20  may extend across the bottom of the pump  10  to close off the engagement wall  18  and to provide a stable resting surface. The resting base  20  may be disc-shaped or cup-shaped and attached to the engagement wall  18  in any known manner. Alternatively, the resting base  20  may be unitarily formed with the engagement wall  18 . As a further alternative, the engagement wall  18  may be left partially or wholly open (e.g., the resting base  20  is not utilized), with an exposed bottom edge defining a resting surface for the pump  10 . 
     With sufficiently large capacity in the reservoir  12 , the engagement wall  18  need not be provided and the inner wall  14  may define a handling surface. The base  16  may also define a resting surface for the pump  10 . 
     The pump  10  includes a pump mechanism  22  which may be of any known configuration to cause delivery of flowable material from the reservoir  12  to nozzle  24  for dispensing the flowable material. The pump mechanism  22  is mounted to the pump body  11  in any known manner. Movable actuator  26  may be associated with the pump mechanism  22  to cause actuation thereof, and the nozzle  24  may be housed in the actuator  26 . Bulkhead  28  may extend across the inner wall  14  to close the reservoir  12  and to accommodate the pump mechanism  22 . A removable cap  23  for storage during non-use is shown in  FIG. 1 , which is removed prior to use. 
     As best shown in  FIGS. 2 and 3 , an inlet tube  30  is provided to communicate the reservoir  12  with the pump mechanism  22 . The inlet tube  30  preferably includes two or more components modularly assembled to define a space  32  that acts as a fluid passageway through the inlet tube  30 . In a preferred embodiment, the inlet tube  30  is defined by two components, an outer tube  34  and a mandrel  36 . The outer tube  34  is disposed coaxially about the mandrel  36  to define the space  32  therebetween. Preferably, the space  32  extends the full length of the outer tube  34 . 
     Preferably, the components  34 ,  36  are rigid. As being rigid, the components  34 ,  36  are not pliant like a standard dip-tube, but rather set in form. The components  34 ,  36  may have some limited elasticity, but preferably require plastic deformation to be permanently altered in shape. It is preferred that the components  34 ,  36  be formed from a polymeric material, more preferably, a thermoplastic. 
     The outer tube  34  includes an inner surface  38  which faces the mandrel  36 , while the mandrel  36  includes an outer surface  40  which faces the outer tube  34 . The inner surface  38  and the outer surface  40  at least partially bound the space  32 . As shown in the Figures, the inner surface  38  and the outer surface  40  can be similarly configured, e.g., to be parallel. In this manner, the space  32  may have equal thickness throughout. For example, the inner surface  38  and the outer surface  40  may be both tapered. Preferably, the inner surface  38  is formed to taper convergently from end  42  of the outer tube  34  and towards the pump mechanism  22 , white the outer surface  40  is preferably formed in similar fashion. This configuration provides a larger opening at the end  42  for receiving the mandrel  36 . Other configurations (e.g., non-parallel configurations) for the inner surface  38  and the outer surface  40  are possible. 
     The outer tube  34  may be formed unitarily with, or attached to, a portion of the pump body  11 , particularly where the flow of material is desired into the pump mechanism  22 . As will be appreciated by those skilled in the art, the outer tube  34  may be readily molded, particularly with the inner surface  38  being tapered. Face-to-face engagement between the outer tube  34  and the mandrel  36  may impede fluid transmission through the space  32 . A longitudinal protrusion or other feature  35  ( FIG. 3 ) may be provided on the inside of the outer tube  34  and/or the outside of the mandrel  36  which acts to minimize face-to-face engagement between the outer tube  34  and the mandrel  36 . The mandrel  36  may be formed with the base  16  or formed separately therefrom and attached thereto. Again, as will be appreciated by those skilled in the art, the mandrel  36  may be readily molded, particularly if the outer surface  40  is tapered. The outer tube  34  and the mandrel  36  may be assembled easily after formation. 
     Advantageously, the space  32  may be defined with various dimensions, depending on the shape and positioning of the outer tube  34  and the mandrel  36 . This allows for the space  32  to be relatively small to accommodate transmission of small doses. Prior art dip tubes are unitarily formed and are difficult to manufacture and assemble, particularly for small dosage volumes. The small bore of dip tubes are also difficult to purge of dust particles, which can lead to contamination of, particularly, pharmaceutical products. The space  32  can be defined to not only accommodate various dose volumes, but also to take into account characteristics of the medium being dispensed, such as viscosity. 
     Preferably, the end  42  of the outer tube  34  is located in proximity to the base  16 . This allows the inlet tube  30  to have access to low volumes of flowable material in the reservoir  12 . As shown in  FIGS. 1 and 2 , the base  16  may include a cup-shaped well  44  at the bottom for the reservoir  12  for maximally collecting remaining flowable material. The end  42  may be formed to extend into the well  44 . 
     Openings  41  may be defined to provide access to the space  32 . The openings  41  may be defined at the end  42  of the outer tube  34 . It is preferred that the base  16  be spaced from the end  42  to provide access thereto. The mandrel  36  may extend beyond the end  42  and/or beyond opposite end  43  of the outer tube  34 . Alternatively, the mandrel  36  may have a length shorter than the outer tube  34 . 
     The openings  41  may be defined continuously or discontinuously between the outer tube  34  and the mandrel  36 . In addition, or alternatively, the openings  41  may be formed as one or more apertures which extend through the outer tube  34  (as shown in dashed lines in  FIG. 2 ). 
     With reference to  FIG. 3 , one or more channels  46  may be defined (e.g., being recessed) in the outer tube  34  and/or the mandrel  36  to define enlarged portions of the space  32 . The channels  46  may extend the length of the inlet tube  30  (e.g., the length of the mandrel  36 ). The channels  46  ensure that the space  32  has sufficient flow area if the outer tube  34  and/or the mandrel  36  is bent or eccentrically located in the outer tube  34 , thereby blocking one or more portions of the space  32 . 
     The space  32  may have a thickness of generally 0.005 inches between the outer tube  34  and the mandrel  36  The thickness of the space  32  may be adjusted. The space  32  may have a length of generally  1 . 5  inches. 
     During use, the pump mechanism  22  will cause flowable material to be drawn from the reservoir  12  and through the inlet tube  30 . As flowable material is dispensed through action of the actuator  26 , the flowable material passes through the space  32  (including any of the channel(s)  46  being utilized), with additional material being drawn in through the end  42  from the reservoir  12 .