Patent Application
20100307603
The present invention relates to a gas pump comprising a stop mechanism wherein the stop mechanism limits the amount of pressure that can be inserted into a volume to be filled by a predetermined value. The present invention may be used to pump air, or other gasses, into structures such as inflatable toys, balloons, mattresses, rafts, and toys or other structures of fixed volume finable by a gas.
The embodiments of the present invention described herein are directed towards a need that has not been addressed by previous implementations of air or gas pumps. Previous types of pumps do not adequately address scenarios where over-pumping can occur by an operator of a gas pump. Over-pumping may occur where the operator is unaware of the pressure at which a structure being filled with a gas will reach the upper limit of its structural integrity and rupture. Further, each relevant structure having a compartment fellable by a gas will vary in its tensile strength and ability to withstand pressure without rupturing. Alternatively, even where a structure does not rupture, its structural integrity may become so degraded by the pressure forces exerted upon it that it is no longer safe to use or may no longer have the ability to effectively serve its intended purpose.
Alternatively, it may be desirable to only have a specified limited pressurization in a fillable volume for a given purpose, in excess of which would be undesirable.
Accordingly, it is desirable to have a gas pump which will not allow the pump operator, or actuator, to cause over-pumping of a fillable structure. The present invention, disclosed herein, provides an efficient, cost-effective means for limiting the pressure that can be inserted into a volume to be filled by a predetermined value. Inflatable structures contemplated by this invention include, but are not limited to, inflatable toys, balloons, mattresses, rafts, and toys or other structures of fixed volume.
A method and apparatus for pumping gas into a fillable structure is provided featuring a pressure limiting feature, wherein the pump, a closure sealing a first opening of the pump at a first end having a one-way valve allowing only the egress of gas from the pump into a volume to be filled, a second opening on the pump at the opposite end, a plunger sealing the second opening and configured to slide along or traverse the pump and thereby express gas from the pump through the one-way valve, wherein a space defined by the pump, the fully traversed plunger, and the closure is a volume, Vt, and a stop to limit the travel of the plunger along the container so a volume, Vb, remains within the space defined by the container, the plunger, and the closure and the pressurization of the volume to be filled is limited by the ratio of Vt to Vb and the volume to be filled can not be pressurized beyond a pressure, Pmax.
While the accompanying claims set forth features of an apparatus and method for limiting pressure as disclosed herein with particularity, embodiments of the device and method may be best understood from the following detailed description taken in conjunction with the accompanying drawings, of which:
The present invention claims priority from United States Provisional Patent Application Ser. No. 61/183,811, filed Jun. 3, 2009, the contents of which are incorporated herein in their entirety by reference thereto.
In instances where the gas pump 100 has a third opening located on the long axis of the pump 101, the third opening may have a one-way valve which allows the ingress of gas to said pump 101. As the operator, or actuator, retracts the plunger 104, the pump 101 having volume Vt fills again with gas. The source of the gas may be atmospheric, an external gas container, a compressor, or any other relevant means of providing gas thereto. The plunger 104 may then be manipulated again to express the entirety of the gas into the target finable structure.
All possible target fillable structures have a maximum pressure value, Pmax. Pmax may be a function of the tensile strength of the materials comprising the Tillable structure. If a fillable structure attains an internal pressure beyond Pmax, then the structure may rupture. Even where the structure does not rupture, its structural integrity may become so degraded by the pressure forces exerted upon it that it no longer is either safe to use or may no longer have the ability to effectively serve its intended purpose. Alternatively, it may be desirable to have a limited amount of pressure in a fillable structure, where pressure in excess of the stated amount is undesirable.
Accordingly, over repeated manipulations of the plunger 104, or even a single manipulation, the target fillable structure may attain an internal pressure which is in excess of the ideal pressure, Pmax, recommended for that particular structure. Theoretically, through over-pumping, the internal pressure of the gas inside the finable structure can approach infinity. As stated, over-pumping may lead to rupturing of the fillable structure or, alternatively, conditions which are dangerous or negatively impact the utility of the fillable structure. This result is undesirable.
As disclosed in
The stop 205 operates to limit the distance along the long axis of the pump 201 that the plunger 204 can travel. The buffer zone is the volume of gas present in between the location of the stop 205, across which the plunger 204 cannot travel, and the first opening 202. Whereupon the plunger 204 has fully traversed the long axis of the pump 201, the gas comprising volume Vt, less volume Vb, may be expressed into the target finable structure.
The stop 205 must be located at an ideal position within the pump 201 in view of Pmax. The ideal location of the stop 205 (i.e. the necessary volume of the buffer zone, Vb) may be determined by the following equation:
V
b=(VtP0)/Pmax
The above equation assumes an ideal system, wherein no heat transfers to or from the environment of the pump and its components occurs. In the above equation, Vb is the desired volume of the buffer zone to be determined; Vt is the total volume of the pump 201; P0 is the initial pressure of the gas within volume Vt; and Pmax is the maximum pressure, or ideal pressure, of the target fillable structure, dependent upon the specifications and intended use of the structure. Accordingly, the stop 205 is positioned along the long axis, adjacent to the first opening as offset by volume Vb of the pump 201. If, however, it is desirable to have an operator, or actuator, perform multiple manipulations of the plunger 204, then the position of stop 205 may be adjusted accordingly, preserving the ratio between Vt and Vb. Furthermore, where practical considerations of scale between the pump 201 and the target fillable structure require, the ratio between Vt and Vb may be adjusted accordingly.
Manipulation of the plunger 204 may cause several different scenarios. The first instance is the “initial state,” the target fillable structure having a maximum pressure value of Pmax, contains no gas and the plunger 204 has not yet been manipulated. Manipulation of the plunger 204 will result in the entirety of the gas comprising volume Vt, less the volume comprising volume Vb, to be expressed to the target finable structure. However, if the pressure of the gas within the target fillable structure is equal to or greater than Pmax during manipulation or traversal of the plunger 204, or upon full manipulation or traversal of the plunger 204, then the pressure within volume Vb will equal Pmax and no further gas will be expressed into the fillable structure. Accordingly, the present invention limits the pressure of the gas in the fillable structure to not exceed maximum compressed air pressure, or Pmax, by the ratio of the total volume of the pump, Vt, to the volume of the buffering zone, Vb.
In a second instance, a gas is already present in the target fillable structure and the pressure of the gas within the structure has not yet exceeded Pmax. Here, the operator, or actuator, may continue to pump until the pressure of the target fillable structure equals Pmax, whereupon further pumping will not be possible, as described above. Accordingly, the problem in the prior art of possible over-pumping is addressed by the present invention.
It should be appreciated by those of skill in the art that the configuration and shape of the pump 201 may take several forms, including, but not limited to, a hand-pump, a foot-pump, a box-pump, a circular pump, or an oval pump. Accordingly, pumps envisioned by the present invention may not have a long axis. Further, a pump may be constructed of any suitable rigid or flexible material. In instances where a flexible material is used, the plunger may be the actual structure of the pump being compressed or traversed. Accordingly, it is to be appreciated that the embodiments discussed are exemplary and not limiting in the construction of the invention disclosed herein.
| Number | Date | Country | |
|---|---|---|---|
| 61183811 | Jun 2009 | US |
