Patent Application
20110116956
The present invention relates to pumps. More particularly, the present invention relates to a single hand operated mini pump for pumping fluid or air.
Hydration systems are portable liquid container systems designed to enable a user engaged in an outdoor activity, for example, a sport, to instantly access the liquid and to drink as needed while on the move. For example, the user may prevent dehydration by drink at a sufficient rate and frequency to replacing body fluids lost through perspiration. By replacing body fluid loss at the required capacity, the user may avoid dehydration and continue to perform the activity at a desired level of performance.
A typical hydration system is designed to operate with minimal use of the user's hands. For example, a hydration system may include a flexible bag or bladder made of a material impermeable to liquids. The flexible bag may be designed to be worn by the user, for example, by being strapped onto the user's back or arm, or to be carried in a backpack or other carrier that is carried without the use of hands. The hydration system enables a user to drink from a liquid in the bladder through a drinking hose that extends from the system to the user's mouth. One end of the drinking hose attaches to a suitable connector on the bladder. The other free end of the drinking hose is generally provided with a drinking valve. The drinking valve typically is self sealing, requiring some sort of action to open it. Thus, when not being used to drink, the drinking valve seals the drinking hose. When wishing to drink, a user may bite or suck on the valve, or perform another similar hands-free operation, to open the drinking valve and drink through the drinking hose. When drinking on the move from a hydration system, the user may suck (as when using a straw) the liquid from the bladder through the drinking tube and into his mouth. Sucking the liquid requires an effort on the part of the user.
The flow rate of a fluid through a tube or hose (that is, the quantity of the fluid that passes a given cross section of the hose per unit of time) partially depends on the difference in fluid pressure between the ends of the hose, and on the resistance of the hose to flow of the fluid. For example, sucking on one end of a hose may reduce the pressure at that end to below atmospheric pressure. The atmospheric pressure at the other end of the hose may then cause the fluid to flow toward the end where sucking is taking place. The flow rate of the liquid in response to the sucking may depend on such factors as the sucking force exerted by user, the amount of liquid in the bladder pressing the liquid up the tube (liquid column pressure), the elevation of the bladder relative to the user's mouth, the altitude (affecting ambient atmospheric pressure). In addition, the flow rate may be affected by resistance to flow due to such factors as hose diameter, constricted passage through the valve apparatus, and any components connected in-line with the hose such as a water filter. Generally speaking in the case of a well-designed hydration system containing a potable liquid, sucking on the drinking tube is generally sufficient to cause the liquid to flow from the bladder of the hydration system to the user's mouth. However there are scenarios were the user is unable to suck and consume the liquid at a sufficient rate in order to avoid dehydration. For example, the user may be engaged in a strenuous activity, such as bicycling, where the user's heavy breathing may prevent effective sucking. Another scenario is high altitude trekking were the user may be short of breath, and where decreased ambient pressure may make sucking less effective.
Another scenario that may render sucking ineffective is incorporation of an in-line filter into the hydration system. For example, potable liquid may not be readily available for filling a hydration system. For example, a hiker hiking far from populated areas may need to fill the bladder of the hydration system from a natural or manmade body or reservoir of water whose quality is not known. For example, when the purity of the water is suspected or known to be substandard, a filter may be used to filter and purify the water. For example, a filter may contain activated charcoal for removing chemical impurities, or a fine-meshed material for removing microbial or particulate impurities. The filter may be mounted in-line such that water flowing from the bladder passes through the filter on the way to the user's mouth. For example, the filter may be mounted near one end of a drinking hose, or between two segments of a drinking hose. Such a filter mounted along the path of the liquid may substantially increase the resistance of the path to flow of the liquid. In such a case, sucking may not provide a sufficient force to cause a liquid to flow through at an acceptable rate.
One way of increasing the flow of a liquid, for example, through a drinking tube, is to use a pump to pump the liquid. For example, a pump may be designed to provide a larger driving force for impelling the liquid than could be provided by sucking. For this reason, pumps for assisting in the transfer of liquid from a hydration system to the user's mouth are known. In general, such pumps are manually powered by performing repetitive hand or foot motions.
A pump that provides a sufficient pumping force for causing a liquid to flow at a satisfactory rate generally requires application of a large manual force. Therefore, many pumps that are known in the art cannot be conveniently operated with a single hand. Operation of such pumps may, therefore, entail interrupting the user's activities until pumping is complete. On the other hand, pumps have been described that may be conveniently powered with one hand, but cannot provide sufficient pumping force to cause an acceptable rate of liquid flow.
Therefore, there is a need for a pump that does not require exerting excessive force in order to operate it, and that delivers fluid at an acceptable rate.
It is an object of the present invention to provide an efficient pump that may pump fluid at an acceptable rate while being operated by a single hand.
Other aims and advantages of the present invention will become apparent after reading the present invention and reviewing the accompanying drawings.
There is thus provided, in accordance with some embodiments of the present invention, a hand operable pump device for pumping fluids. The device includes a hollow body, with an inlet port and an outlet port, the inlet port provided with a one-way valve permitting fluid flow into the pump and the outlet port provided with a one-way valve permitting fluid flow out of the pump. The device further includes an oval piston designed to be pressed inwardly from an initial position by the hand, decreasing the volume of an oval chamber with a corresponding oval cross-section, the chamber being located within the pump and fluidically connected with the inlet and outlet ports, and to return to the initial position when released, increasing the volume of the chamber.
Furthermore, in accordance with some embodiments of the present invention, the inlet and outlet ports are located along the long axis of the oval cross-section.
Furthermore, in accordance with some embodiments of the present invention, the one-way valves comprise flapper valves.
Furthermore, in accordance with some embodiments of the present invention, the flapper valves comprise umbrella valves.
Furthermore, in accordance with some embodiments of the present invention, the inlet and outlet ports are each connected to a tube.
Furthermore, in accordance with some embodiments of the present invention, the piston is a spring operated piston.
Furthermore, in accordance with some embodiments of the present invention, the body comprises a cylinder with oval cross-section which is provided with a hinged cover pivotally attached to the body for pressing the piston.
Furthermore, in accordance with some embodiments of the present invention, the piston includes a domed surface and the cover includes a corresponding concave surface.
Furthermore, in accordance with some embodiments of the present invention, the device is provided with a latch to lock the cover at a closed position with the piston pressed inwardly.
Furthermore, in accordance with some embodiments of the present invention, the latch comprises a pivotable hook.
Furthermore, in accordance with some embodiments of the present invention, the piston includes an inner surface which defines with an opposite surface of the chamber a void, allowing flow of fluid through the pump even when the piston is fully pressed inwardly.
In order to better understand the present invention, and appreciate its practical applications, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention.
A hand pump in accordance with embodiments of the present invention is designed to pump a liquid at an acceptable rate while being operated by a single hand. The pump includes a hollow body enclosing a cylinder with an oval cross section. The cylinder is closed at one end. A piston with a corresponding oval shape is designed to slide back and forth along the axis of the cylinder, closing the open end of the cylinder. An oval shaped rubber ring forms a seal between the piston and the walls of the cylinder in the manner of an O-ring. Motion of the piston may vary the volume of a pump chamber formed by the inner surface of the piston, the inside of the walls of the cylinder, and the closed end of the cylinder. The closed end of the cylinder acts as a fixed floor of the pump chamber. Inwardly pressing the outside of the piston pushes the piston toward the chamber floor, reducing the volume of the pump chamber. As the piston is pushed toward the chamber floor, a resilient element is deformed. For example, a spring may be configured such that it may be compressed between the piston and the chamber floor. When the pressing force is removed, the resilient element returns to its non-deformed shape. For example, a compressed spring may expand. In returning to its non-deformed shape, the resilient element forces the piston away from the chamber floor, increasing the volume of the pump chamber.
A proximal end of an inlet tube connects to an inlet port in the chamber floor. The inlet port is located near one end of the long oval axis of the oval-shaped chamber floor. The inlet port is provided with a one-way valve. The one-way valve is configured to enable fluid to flow from the inlet tube into the pump chamber, but not from the pump chamber into the inlet tube. The distal end of the inlet tube may be provided with a connector. For example, the inlet tube connector may be configured to connect to a source of liquid. For example, the inlet tube may connect to a hose whose other end is connected to a container of a hydration system.
A proximal end of an outlet tube connects to an outlet port in the chamber floor. The outlet port is located on the long oval axis of the oval-shaped chamber floor, near the end of the axis opposite the end where the inlet port is located. The connection between the outlet tube and the pump chamber is provided with a one-way valve. The one-way valve is configured to enable fluid to flow out of the pump chamber into the outlet tube, but not from the outlet tube into the pump chamber. The distal end of the outlet tube may be provided with a connector. For example, the outlet tube connector may be configured to connect to a drinking tube or port.
One-way valves are known in the art. For example, a one-way valve may include a flapper valve. A flapper valve includes a flap that is configured to bend in one direction, thus opening the valve, but not in the opposite direction, thus shutting the valve. For example, the flapper valve may typically include an umbrella valve with an umbrella shaped flap. A stem of the umbrella shaped flap holds the flap adjacent to a grating. The grating includes solid ribs and openings between the ribs. The umbrella shaped flap may bend away from the grating. However, the ribs prevent the umbrella shaped flap from bending in the opposite direction, through grating. The openings enable fluid to flow through the grating. Thus, a flow through the grating in the direction toward the flap may bend the flap away from the grating, enabling the flow to continue. On the other hand, a flow flowing toward the grating from the side with the flap may tend to push the flap against the grating, sealing the grating and preventing flow through the grating. Thus, an umbrella shaped valve at the inlet port may be oriented with its flap on the inner, chamber-facing, side of the inlet port. An umbrella shaped valve at the outlet port, on the other hand, may be oriented with its flap on the outside of the outlet port, facing away from the chamber.
The flow rate of a pumped fluid through the hand pump is partially affected by the areas of the inlet port and the outlet port. Increasing the areas of the ports may lead in an increase of the flow rate of a pumped fluid. However, the dimensions of the chamber floor must be large enough to accommodate the areas of the ports. In order for the pump to operate effectively, the dimensions of the piston surface must be approximately equal to those of the chamber floor. The larger the area of the piston surface, however, the greater the force that must be applied to the piston in order to press it inward (assuming a given fluid pressure). Thus, an oval shaped chamber floor may accommodate two circular ports of a larger area than would be accommodated by a circle whose area is equal to that of the oval. Thus, by providing an oval shaped chamber floor, the flow rate of a pumped fluid through the hand pump may be maximized for a given applied pumping force. In addition, the oval shaped may be conveniently gripped with one hand. Outer surfaces of the hand pump may be further provided with ragged or textured surfaces that enable convenient or secure gripping of the pump.
A hand pump in accordance with embodiments of the present invention may include a hinged cover that is configured to close over the outer side of the piston and the open end of the cylinder. For example, a central column-shaped portion of the piston may extend outward. The outer end of the central column may include a convex or dome-shaped. The inner surface of the hinged cover may have a corresponding concave shape. Thus, when the hinged cover is opened or closed, the inside of the hinged cover may slide over the dome-shaped end of the central column of the piston. The sliding of the hinged cover over the central column may facilitate pushing the piston inward by closing the hinged cover, and enabling the piston to move outward by opening the hinged cover.
The hinged cover may be provided with a latch that enables latching the cover shut when the pump is not in use. For example, the latch may include a pivotable hook-shaped extension that may hook onto a catch provided on the pump body. When the latch is unlatched, a resilient element may push the piston outward, causing the hinged cover to open. Pushing the piston outward increases the volume of the pump chamber and draws fluid from the inlet tube into the pump chamber through the inlet port and one-way inlet valve. The one-way outlet valve at the outlet port may prevent fluid from being drawn into the pump chamber from the outlet tube.
A user may then operate the pump by pushing on the hinged cover, closing the hinged cover. Pushing the hinged cover closed pushes the piston inward toward the chamber floor. Pushing the piston toward the chamber floor may force liquid out of the pump chamber into the outlet tube through the outlet port and the one-way outlet valve. The one-way inlet valve at the inlet port, however, may prevent liquid from flowing out of the pump chamber into the inlet tube. Pushing the piston toward the chamber floor also compresses the spring. Thus, when the user stops pushing on the hinged cover, the spring may again push the piston outward, again drawing water from the inlet tube into the chamber.
Repeatedly closing the hinged cover and releasing may thus pump water from the inlet tube and into the outlet tube. The pumping force may thus cause the liquid to flow at an acceptable rate from a source of liquid connected to the inlet tube, toward a desired destination connected to the outlet tube. When pumping is complete, the hinged cover may be closed and latched shut.
The inner surface of the piston, in accordance with some embodiments of the present invention, may be shaped so as to include an indented hollow space. The indented hollow space may enable fluid to flow from the inlet port to the outlet port via the pump chamber even when the piston is pushed fully inward. For example, the indented hollow may enable the flow of fluid through the pump, for example, when impelled by sucking on the outlet tube. Thus, fluid may flow when the hinged cover is closed and latched. Thus, even if the hand pump remains connected when use of the pump is not necessary, the pump may not prevent or significantly impede flow of the fluid. For example, the hand pump may be connected between two components of a drinking apparatus of a hydration system. For example, a user may wish to drink from the hydration system by sucking, for example, where no filter is needed. In this case, the user may drink from the drinking apparatus without disconnecting the pump from the drinking apparatus.
A hand pump in accordance with embodiments of the present invention may enable other uses. For example, a pump may enable extracting liquid from a hydration system for purposes other than drinking. For example, water from a hydration system may be sprayed on a user's face or body for cooling purposes. Water may be extracted to clean a wound or food. In addition, a hand pump may enable a user to estimate liquid intake to the user's body. For example, if the capacity of the pump is known (a typical value may be about 15 milliliters), the user may know that with each pump cycle the liquid intake is approximately equal to the pump capacity.
In another possible application, a hand pump in accordance with embodiments of the present invention may be connected such as to pump air from a drinking hose of a hydration system into a bladder of the hydration system. For example, the inlet tube of the hand pump may be connected to the drinking tube and the outlet tube may be connected to the bladder. In this case, operation of the pump may pump air into the bladder. Pumping air into the bladder may increase the fluid pressure in the bladder, making it easier to suck fluid from the bladder without subsequent use of the pump.
Reference is now made to the accompanying Figures.
Cylinder walls 14 enclose a hollow cylinder with oval cross section. One end of the hollow cylinder is closed by chamber floor 39, which is also oval shaped. Piston 28 closes the end of the hollow cylinder opposite chamber floor 39. Piston 28 may be moved inward or outward within cylinder walls 14. Closing hinged cover 12 may push piston 28 inward. Opening hinged cover 12 may enable piston 28 to move outward. Piston 28 has a oval shape corresponding to the oval cross section of the hollow cylinder enclosed by cylinder walls 14. Thus, piston 28 fits within cylinder walls 14.
Inlet tube 22 and outlet tube 26 may be configured to connect to one or more corresponding connectors on other devices. For example, inlet tube 22 and outlet tube 26 may be configured to connect to one or more components of a hydration system. For example, inlet tube 22 may be configured to connect to one or more components associated with a fluid container, such as a hose or port. Outlet tube 26 may be configured to connect to one or more components associated with drinking apparatus. Both inlet tube 22 and outlet tube 26 are provided with O-rings 23 for sealing any openings between the tubes and attached components.
Moving piston 28 inward or outward decreases or increases, respectively, the volume of pump chamber 15. Pump chamber 15 is bounded by cylinder walls 14, chamber floor 35, and piston 28. Thus, inward motion of piston 28 toward chamber floor 39 decreases the volume of pump chamber 15. On the other hand, outward motion of piston 28 away from chamber floor 39 increases the volume of pump chamber 15. Oval ring 32, constructed of rubber or a similar impermeable elastic material, surrounds piston 28, sealing any gap between piston 28 and cylinder walls 14 in the manner of an O-ring. Thus, oval ring 32 may prevent fluid from escaping from pump chamber 15 via a gap between piston 28 and cylinder walls 14.
Chamber floor 35 is fluidically connected to inlet tube 22 via an inlet port 35, and to outlet tube 26 via outlet port 37. One-way inlet umbrella valve 36 enables fluid to flow inward from inlet tube 22 to pump chamber 15 via inlet port 35, but prevents opposite outward flow. Similarly, one-way outlet umbrella valve 38 enables fluid to flow outward from pump chamber 15 to outlet tube 26 via outlet port 37, but prevents opposite inward flow. Thus, when outward motion of piston 28 increases the volume of pump chamber 15, the outward motion may draw fluid into pump chamber 15 from inlet tube 22. Subsequent inward motion of piston 28, decreasing the volume of pump chamber 15, may force fluid out of pump chamber 15 into outlet tube 26. Thus, inward and outward motion of piston 28 may pump a fluid from inlet tube 22 to outlet tube 26. As seen in
Outlet tube 26 may be configured to connect to one or more other devices. For example, outlet tube 26 may connect to drinking port 24. Drinking port 24 may be provided with protective cover 25.
O-rings 23 are provided to seal interfaces around the edges of components of hand pump 10 that are inserted during assembly of hand pump 10. Additional O-rings 23 may be provided on inlet tube 22 and outlet tube 26.
Indented inner piston surface 40 may ensure that piston 28, even when completely pressed inward toward chamber floor 39, does not prevent flow of fluid from inlet tube 22 to outlet tube 26. For example, the shape of indented inner piston surface 40 may enable one-way inlet umbrella valve 36 to open freely when piston 28 is fully inserted. For example, an external force may be applied to a fluid to impel the fluid to flow. For example, a person may suck on a device connected to outlet tube 26. In this case, even when piston 28 is fully pressed inward, enough space remains between indented inner piston surface 40 and chamber floor 39 to enable flow of the fluid from inlet tube 22 to outlet tube 26.
During operation of hand pump 10 to pump a fluid from inlet tube 22 to outlet tube 26, piston 28 is alternatively pressed inward and released to enable piston 28 to extend outward.
Thus, embodiments of the present invention provide a hand pump that may be operated with a single hand but is capable of pumping a fluid at an acceptable rate.
It should be clear that the description of the embodiments and attached Figures set forth in this specification serves only for a better understanding of the invention, without limiting its scope.
It should also be clear that a person skilled in the art, after reading the present specification could make adjustments or amendments to the attached Figures and above described embodiments that would still be covered by the present invention.
