Abstract:
A fluid delivery device includes: a first chamber configured to receive fluid from a fluid reservoir; a second chamber configured generate a vacuum therein to apply pressure to the fluid in the first chamber to enable the fluid in the first chamber to be output from the fluid delivery device; and a flow control member configured to allow the fluid in the first chamber to flow through the flow control member into the fluid reservoir at a predetermined flow rate to decrease the vacuum in the second chamber.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 USC 119(e) of U.S. Provisional Application No. 62/217,390 filed on Sep. 11, 2015, the entire disclosure of which is incorporated herein by reference for all purposes. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    The following description generally relates to vacuum-driven fluid delivery devices. 
         [0004]    2. Description of Related Art 
         [0005]    A vacuum-driven fluid delivery device outputs fluid under a force generated by a vacuum in a vacuum chamber. An example of a vacuum-driven fluid delivery device is disclosed in U.S. Pat. No. 8,973,847 by lammatteo and Bicej, issued on Mar. 10, 2015, the entire disclosure of which is incorporated herein by reference for all purposes. When such a fluid delivery device remains unused with a volume of vacuum in the vacuum chamber (i.e., in a “charged” state), the fluid delivery device is susceptible to loss of some or all of the volume of the vacuum over time. That is, external gases permeate into the vacuum chamber over time and replace at least a portion of the vacuum chamber that was previously occupied by the vacuum, thereby reducing the maximum vacuum volume of the vacuum chamber. Such a reduction in the maximum vacuum volume reduces the maximum duration of fluid output from the fluid delivery device. 
         [0006]    Accordingly, it is desirable to provide a vacuum-driven fluid delivery device that prevents undesirable loss in maximum vacuum volume of the vacuum chamber during storage of the device in a charged state. 
       SUMMARY 
       [0007]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
         [0008]    In one general aspect, a fluid delivery device includes: a first chamber; a second chamber; a reservoir configured to contain a fluid; a first valve configured to control a first flow of the fluid between the fluid reservoir and the second chamber; a flow control member configured to control a second flow of the fluid between the second chamber and the fluid reservoir; a first plunger configured to generate a vacuum in the first chamber responsive to movement of the first plunger in a first direction; and a second plunger configured to move in the first direction in response to movement of the first plunger in the first direction to cause a portion of the fluid to flow from the fluid reservoir through the first valve and into the second chamber, and configured to apply a force generated by the vacuum to the portion of the fluid in the second chamber; and an outlet including a second valve configured to be actuated to output the portion of the fluid from the second chamber outside of the fluid delivery device, wherein, when the second valve is not actuated, the flow control member is configured to allow the portion of the fluid in the second chamber to flow through the flow control member into the fluid reservoir at a predetermined flow rate. 
         [0009]    When flow control member is in a closed configuration, the flow control member may only partially blocks a flow of the portion of the fluid in the fluid chamber from the fluid chamber to the fluid reservoir. 
         [0010]    The flow control member may include a fixed position valve. 
         [0011]    The first valve may be configured to prevent the portion of the fluid in the second chamber from flowing out of the second chamber through the first valve. When the second valve is not actuated, the second valve may be biased to prevent the portion of the fluid in the fluid chamber from flowing out of the second chamber through the second valve. 
         [0012]    In response to the portion of the fluid in the second chamber flowing through the flow control member into the fluid reservoir, the first plunger and the second plunger may move in a second direction opposite the first direction and the vacuum in the first chamber may decrease. 
         [0013]    In another general aspect, a fluid delivery device includes: a first chamber configured to receive fluid from a fluid reservoir; a second chamber configured generate a vacuum therein to apply pressure to the fluid in the first chamber to enable the fluid in the first chamber to be output from the fluid delivery device; and a flow control member configured to allow the fluid in the first chamber to flow through the flow control member into the fluid reservoir at a predetermined flow rate to decrease the vacuum in the second chamber. 
         [0014]    The fluid control member may include a fixed position valve. 
         [0015]    The fixed position valve may be fixed in a closed position in which a flow of the fluid in the first chamber into the fluid reservoir through the valve is only partially restricted. 
         [0016]    Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a side cross-sectional view of a vacuum-driven fluid delivery device in an uncharged state, according to an embodiment. 
           [0018]      FIG. 2  is a side cross-sectional view of the vacuum-driven fluid delivery device in a charged state during a charging operation. 
           [0019]      FIG. 3  is a side cross-sectional view of the vacuum-driven fluid delivery device in a fully charged state. 
       
    
    
       [0020]    Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. 
       DETAILED DESCRIPTION 
       [0021]    The following description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent to those of ordinary skill in the art. The sequences of operations described herein are merely examples, and are not limited to those set forth herein, but may be changed as will be apparent to one of ordinary skill in the art, with the exception of operations necessarily occurring in a certain order. Also, descriptions of well-known functions and constructions that are well known to one of ordinary skill in the art may be omitted for increased clarity and conciseness. 
         [0022]    The features described herein may be embodied in different forms, and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete, and will convey the full scope of the disclosure to one of ordinary skill in the art. 
         [0023]      FIGS. 1-3  show a vacuum-driven fluid delivery device  10  according to an example embodiment. More specifically,  FIG. 1  shows the fluid delivery device  10  in an uncharged or rest state in which the device is not configured to output fluid  2 ,  FIG. 2  shows the fluid delivery device  10  in a partially charged state during a charging operation for preparing the device  10  to output fluid  2 , and  FIG. 3  shows the fluid delivery device  10  in a fully charged state in which the device  10  is configured to output fluid  2 . The fluid  2  may be any liquid or gas, for example. 
         [0024]    Referring to  FIGS. 1-3 , the fluid delivery device  10  includes a main body  20 , a plunger assembly  50 , a check valve  60 , a flow control member  70 , a fluid outlet  90 , and a fluid reservoir  100  configured to store a volume of the fluid  2 . 
         [0025]    The main body  20  includes a vacuum chamber  30  configured to contain a vacuum and a fluid chamber  40  configured to receive fluid from the fluid reservoir  100 . The plunger assembly  50  includes a vacuum plunger  52  configured to reciprocate within the vacuum chamber  30 , a fluid plunger  54  configured to reciprocate within the fluid chamber  40 , and a connecting member  56  connecting the vacuum plunger  52  and the fluid plunger  54  to each other. Due to their interconnection by the connecting member  56 , the vacuum plunger  52  and the fluid plunger  54  may be configured to move together simultaneously.  FIGS. 1-3  merely provide an example configuration of the plunger assembly  50 , and other configurations are possible. For example, instead of being connected in a side-by-side configuration as shown, the vacuum plunger  52  and the fluid plunger  54  may be connected in a coaxial configuration. 
         [0026]    The check valve  60  is in fluid communication with the fluid chamber  40  and the fluid reservoir  100 , and is configured to control flow of the fluid  2  between the fluid reservoir  100  and the fluid chamber  40 . The check valve  60  includes a tubular housing  62  and a sealing member (e.g., a ball member or stopper)  64  configured to reciprocate within the housing  62  to control the flow of the fluid between the fluid reservoir  100  and the fluid chamber  40 . The sealing member  64  is biased towards a sealing position with an inner wall surface of the housing  62 , in which the check valve  60  is in a closed configuration and the sealing member  64  prevents the flow of the fluid  2  between the fluid reservoir  100  and the fluid chamber  40 . 
         [0027]    As will be described in detail later, the sealing member  64  may be urged under fluid pressure into an unsealing position, in which the check valve  60  is in an open configuration and the sealing member  64  allows flow of the fluid  2  between the fluid reservoir  100  and the fluid chamber  40 . 
         [0028]    The flow control member  70  is in fluid communication with the fluid chamber  40  and the fluid reservoir  100 , and is configured to control flow of the fluid  2  between the fluid chamber  40  and the fluid reservoir  100 . The flow control member  70  is configured to enable limited flow of the fluid  2  from the fluid chamber  40  to the fluid reservoir  100 , and is configured to prevent flow of the fluid  2  from the fluid reservoir  100  to the fluid chamber  40 . The flow control member  70  may be a fixed position valve in which a sealing member  74  (e.g., a ball or stopper) is disposed in a housing  72  and biased in a sealing position to only partially restrict flow of the fluid  2  from the fluid chamber  40  to the fluid reservoir  100  through the flow control member  70 . For example, the flow control member is fixed in a closed position in which the sealing member  74  is biased in a sealing position by a biasing member such as a spring  75  such that the sealing member  74  only partially restricts an interior fluid pathway of the flow control member  70 . In other words, the sealing member  74  highly restricts/partially blocks flow of the fluid  2  from the fluid chamber  40  to the fluid reservoir  100  in the sealing position, but does not provide a completely fluid-tight seal. 
         [0029]    Alternatively, the flow control member  70  may be an adjustable valve that may be adjusted to control the flow rate of the fluid  2  into the fluid reservoir  100  through the valve. Although the flow control member  70  is shown and described as a ball-and-spring or stopper-and-spring type valve, the flow control member  70  may be any other known type of fixed or adjustable position valve. 
         [0030]    The fluid outlet  90  controls the output of the fluid  2  from the device  10 . More specifically, as will be described later in more detail, the fluid outlet  90  includes an outlet valve  92  that is configured to control the flow of the fluid  2  out of the fluid chamber  40  through the fluid outlet  90 . The outlet valve  92  is biased in a closed configuration to prevent the fluid  2  in the fluid chamber  40  from flowing out of the fluid outlet  90 . The outlet valve  92  may be selectively actuated by an actuator in a known manner to be placed in a configuration in which the fluid  2  in the chamber is allowed to flow out of the fluid outlet  90 . For example, the fluid outlet  90  may be connected to a spray nozzle (not shown) in a known manner such that actuation of the outlet valve  92  produces a spray of the fluid  2  outside of the device  10  from the nozzle. 
         [0031]    The location and configuration of the fluid outlet  90  shown in  FIGS. 1 and 2  merely correspond to one example. Other locations and configurations are possible. For example, the fluid outlet  90  may communicate with a hollow passage in the fluid plunger  54  or another passage in the fluid chamber  40  configured to allow the fluid  2  to flow into the fluid outlet  90 . 
         [0032]    As shown in  FIG. 1 , when the device  10  is in an uncharged state, and thereby not prepared to output fluid  2  through the fluid outlet  90 , the vacuum plunger  52  and the fluid plunger  54  are at their lowermost positions of their strokes within the vacuum chamber  30  and the fluid chamber  40 , respectively. Accordingly, the vacuum chamber  30  and the fluid chamber  40  have no volume or nearly no volume. The check valve  60  is in the closed configuration due to the sealing member  64  being biased in its sealing position. 
         [0033]    As shown in  FIG. 2 , in order to charge the device  10 , the vacuum plunger  52  and the fluid plunger  54  are moved upward by a user away from their lowermost positions. The upward movement of the vacuum plunger  52  creates a vacuum in the vacuum chamber  30 , and the volume of the vacuum increases with greater upward movement of the vacuum plunger  30 . The upward movement of the fluid plunger  54  creates a negative pressure which draws fluid  2  from the fluid reservoir  100  into the fluid chamber  40  against the sealing bias of the sealing member  64 . That is, as the fluid plunger  54  is moved upward, the force applied by the fluid  2  in the fluid reservoir  100  to the sealing member  64  is sufficient to overcome the sealing bias force of the sealing member  64 . Thus, the sealing member  64  moves into its unsealing position, thereby allowing the fluid  2  to flow from the fluid reservoir  100  into the fluid chamber  40 . The amount of the fluid  2  that enters the fluid chamber  40  increases with increased upward movement of the fluid plunger  54 . 
         [0034]    When charging the device  10 , upward movement of the vacuum plunger  30  and the fluid plunger  40  can be stopped when the vacuum plunger  30  and the fluid plunger  40  reach their uppermost positions corresponding to the fully charged state of the device  10  shown in  FIG. 3 , or at any intermediate positions (e.g., the position shown in  FIG. 2 ) of the vacuum plunger  30  and the fluid plunger  40  between their lowermost positions and their uppermost positions. When the vacuum plunger  30  and the fluid plunger  40  are in the intermediate positions, the device  10  is considered to be in a partially charged state. 
         [0035]    When the device  10  is in a charged state and the user stops moving the vacuum plunger  30  and the fluid plunger  40 , the sealing member  64  returns to the sealing position under its bias force, thereby placing the check valve  60  in the closed configuration and restricting flow of the fluid  2  from the fluid chamber  40  to the fluid reservoir  100 . The vacuum in the vacuum chamber  30  applies a force Fv to the vacuum plunger  52  in a first direction. Due to its connection with the fluid plunger  54 , the vacuum plunger  52  transmits the force Fv to the fluid plunger Fv. As a result, the fluid plunger  54  applies a force F o , in the first direction, to the fluid  2  in the fluid chamber  40 , thereby “charging” or pressurizing the fluid  2  in the fluid chamber  40  such that the fluid  2  can be selectively output from the fluid chamber  40  through the fluid outlet  90  to an outside of the device  10  under the force F o . 
         [0036]    The fluid  2  is prevented from being output from the fluid chamber  40  through the fluid outlet  90  while the outlet valve  92  remains closed. When the outlet valve  92  is actuated and thereby opened by a user, the fluid  2  may be sprayed or otherwise output through the fluid outlet  92  at a predetermined flow rate. More specifically, when the outlet valve  92  is opened, the fluid  2  may be continuously sprayed or otherwise output through the fluid outlet  92  under the force F o  applied by the fluid plunger  54  as the fluid plunger  54  is urged downward by the force Fv generated by the vacuum in the vacuum chamber  30 . While the fluid  2  is output through the fluid outlet  92 , the vacuum plunger  30  and the fluid plunger  40  move downward towards their lowermost positions. The fluid  2  may be output through the fluid outlet  90  until the vacuum is depleted in the vacuum chamber  30  and the fluid  2  is depleted in the fluid chamber, or until the outlet valve  92  is closed. Once the outlet valve  92  is closed, the fluid  2  is no longer output through the fluid outlet  90 . When the vacuum is depleted in the vacuum chamber  30  and the fluid  2  is depleted in the fluid chamber, the vacuum plunger  52  and the fluid plunger  54  are returned to their lowermost positions such that the device  10  is in the uncharged state. 
         [0037]    When conventional vacuum-driven fluid delivery devices are stored (i.e., not operated) in a charged state, problems can occur. One such problem is that external gases from the surrounding environment can permeated into the vacuum chamber over time and occupy some or all of the volume initially containing the vacuum. Thus, the maximum volume of the vacuum in the vacuum chamber can decrease over time. Since the maximum duration of fluid output (e.g., spray) from the fluid outlet is determined by the volume of the vacuum in the vacuum chamber, a decrease in the maximum volume of the vacuum adversely affects performance of the device. 
         [0038]    Additionally, when conventional vacuum-driven fluid delivery devices are stored in a charged state, the forces (F v , F o ) generated by the vacuum in the vacuum chamber can place excessive stresses on the components of the device, causing the components to become damaged, deform or break when subjected to the vacuum over an extended period of time. Furthermore, according to examples, some or all of the components of vacuum-driven fluid delivery devices are constructed of thermoplastic materials, which suffer from creep when subjected to loading/stress over a sufficient period of time. 
         [0039]    In order to avoid the above-described problems, the flow control member  70  is configured to allow the vacuum in the vacuum chamber  30  to slowly decrease when the device  10  is stored in a charged state by allowing a slow, controlled flow of the fluid  2  in the fluid chamber  40  into the fluid reservoir  100 , as indicated above. More specifically, as the fluid  2  flows from the fluid chamber  40  to the fluid reservoir  100  through the gap or passage in the flow control member  70 , the vacuum plunger  52  and the fluid plunger  54  move towards their lowermost positions and the volumes of the vacuum chamber  30  and fluid chamber  40  slowly decrease. If the device  10  is stored for a sufficient period of time, the vacuum plunger  52  and the fluid plunger  54  will return towards their lowermost positions, placing the device  10  in the uncharged state (shown in  FIG. 1 ) in which the vacuum chamber  30  and fluid chamber  40  have volumes of zero. Thus, external gases are prevented from permeating into the vacuum chamber  30  and stresses on the components of the device  10  due to charging are relieved. 
         [0040]    Although the foregoing description relates to an example in which the fluid plunger  54  is driven by a vacuum in the vacuum chamber  30 , the fluid plunger  54  may alternatively be driven by a power spring (not shown) in a known manner. That is, a power spring may provide a biasing force in the downward direction such that movement of the fluid plunder  54  in the upward direction to charge the device results in the power spring applying a downward force to the fluid plunger  54 , and the fluid plunger applies the force F o  to the fluid  2  in the fluid chamber  40 . In such an example employing a power spring, the flow control member  70  provides the benefit of relieving stresses on the components of the device due to charging by allowing the fluid in the fluid chamber  40  to slowly return to the fluid reservoir  100  when the device is stored in a charged configuration. 
         [0041]    Words describing relative spatial relationships, such as “below”, “beneath”, “under”, “lower”, “bottom”, “above”, “over”, “upper”, “top”, “left”, and “right”, “upward”, “downward”, “uppermost” and “lowermost” may be used to conveniently describe spatial relationships of one device or elements with other devices or elements. Such words are to be interpreted as encompassing a device oriented as illustrated in the drawings, and in other orientations in use or operation. For example, an example in which an element of a device is described as moving upward also encompasses the element moving downward when the device is flipped upside down in use or operation. 
         [0042]    While this disclosure includes specific examples, it will be apparent that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system or device are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.