Abstract:
A compensating pressure regulator comprising a single stage regulating device for controlling the flow of compressed gas therethrough; and a compensating device for automatically adjusting transient pressure conditions to provide a substantially uniform gas pressure output by use of a pin like-piston having dual sources of pressure thereon. The compensating pressure regulator for use with bottled gas on portable tools.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This is the regular utility application as filed from U.S. Provisional Patent Application Ser. No. 61/208,731 filed Feb. 27, 2009 by the same inventor, and claims priority to such. 
    
    
     REFERENCE TO FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     NA 
     REFERENCE TO JOINT RESEARCH AGREEMENTS 
     NA 
     REFERENCE TO SEQUENCE LISTING 
     NA 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to pneumatic tools, and, particularly, relates to portable pneumatic tools, and, in greater particularly, relates to devices for controlling the flow of gas thereto. 
     2. Description of the Prior Art 
     With the advancement of technology in the construction industry, the use of powered portable devices has become more common. Typically, such devices were powered by an electric generator which converted the AC to DC power as needed or ran a compressor. The powered devices were connected by long electrical cords or air hoses to these devices. The disadvantages are clearly evident such as safety from tripping over cords and hoses, limited range, limited number of operating devices, and the need to transport heavy generators and compressors to construction sites. The next generation of portable powered devices use compact batteries and bottled compressed gas. In regards to portable powered devices using compressed gas, stepping down the gas pressure requires the use of complex pressure regulators. 
     In particular, pressure regulators are commonly used in the construction trades to regulate the pressure received by pneumatic tools from compressors or other pressure sources. These tools have an optimum range of operation for the pressurized fluid stream which provides them energy to operate. However, most compressors and other conventionally used pressurized fluid stream sources operate at fluid pressures well above the optimum range required by the tool connected to them. 
     Common power tools such as pneumatic air hammers which drive nails into wood, pneumatic staplers, and pneumatic saws used in construction, and in other applications such as dental offices, require a constant regulated fluid stream to operate effectively. Currently such a regulated pressurized fluid stream is maintained by a fluid pressure regulator located between the conventional pressurized fluid source and the connected tool. 
     Once such regulator is disclosed by U.S. Pat. No. 5,860,447 that is a single stage pressure regulator with a bleed piston cooperatively engaged thereto. In the normal state of operations, the output pressure pushes the regulator piston against the bleed piston. When the source of pressure is removed from the regulator, the bleed piston is forced to open the seal and this allows the compressed gas in the tool to flow through the regulator piston, and out through bleed vents and thus “de-energizing” the pressure operated tool to prevent accidental operation. 
     Another regulator of pressurized gas is disclosed by U.S. Pat. No. 7,325,397 that is particularly directed at providing power to nail guns. Because of the high pressure in the carbon dioxide container, a two stage regulator is used. The first regulator reduces substantially the pressure to just above a desired amount. A fine pressure adjustment unit is connected down line from the first regulator and is used to bring the operating pressure into the range to be used by the pneumatic tool such as a nail gun. Neither of the patents are concerned with the occurrence of pressure spikes, high or low, in the input stream. 
     Accordingly, there is an established need for a compensating pressure regulator having means for eliminating transient spikes. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed at construction and automotive tools requiring a pressurized source of gas to operate. 
     The present invention further provides means for controlling the flow of the pressurized gas to the construction tool. 
     In the present invention, the compensating pressure regulator has an output fitting attached to the output side of the pressure regulator. The input side of the pressure regulator is attached to the output of a bottle of compressed gas via threaded connection. The pressure regulator provides directly an operable range of gas pressure to conventional pneumatic tools such as nail guns and wrenches. Additional adjustment to the pressure may be had by an adjustment means located on top of the regulator. The regulator further comprises a single stage regulating device for controlling the flow of compressed gas therethrough; and a compensating device for automatically adjusting transient pressure conditions to provide a substantially uniform gas pressure output. The compensating device includes a double acting pin like-piston that has the input pressure on one side and the output pressure on the other side receiving the appropriate pressure by a channel connecting n pressure output chamber to a lower pressure chamber. 
     An embodiment of the present invention is to provide a source of compressed gas in a controlled manner to a pressure-operated tool. 
     Another embodiment of the present invention is to provide a compensating pressure regulator for controlling the output of gas to the pressure operated tool. 
     A further embodiment of the present invention is to provide a compensating pressure regulator that substantially reduces pressure spikes, high or low, to the pressure operated tool. 
     A further embodiment of the present invention to provide a compensating pressure regulator that uses a single stage to reduce the input pressure from the bottle of compressed gas to an operating pressure. 
     Yet a further embodiment of the present invention is to provide a compensating pressure regulator that is of simple design and is easily manufactured. 
     These and other objects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The preferred embodiments of the invention will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the invention, where like designations denote like elements, and in which: 
         FIG. 1  is a perspective view of one embodiment of the present invention being a portable gas operated construction tool; 
         FIG. 2  is a cross-sectional side view of the compensating pressure regulator in an equilibrium state; and 
         FIG. 3  is an enlarged cross sectional view of a compensating device showing another embodiment of  FIG. 2 . 
     
    
    
     Like reference numerals refer to like parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is directed at a pressure regulator for use on portable tools using a portable source of compressed gas. 
     It should be understood that the present invention is not limited to use on portable compressed gas cylinders, but may be used on any source of pressurized gas or fluids to reduce or substantially eliminate pressure transient conditions such as spikes, either high pressure or low pressure, and is not limited to the use on construction tools, but other devices that require substantially uniform operating pressures. Any and all cited references are incorporated by reference hereto as to their teachings. 
     Turning to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is initially directed to  FIG. 1  which illustrates by schematic view a portal compressed gas operated tool system  10  constructed according to the present invention. 
     As best shown in  FIG. 1 , a portable bottle  12  of compressed gas provides the source of power to a conventional gas powered tool  20 . This bottle  12  may be of conventional design and contains pressurized carbon dioxide or other appropriate gases at a pressure of about 150 kg/cm 2  and have a weight of about 2 pounds. The top of the bottle  12  has a threaded outlet  13  with a pressure on/off valve of the Schrader type or the like. A compensating pressure regulator  14  is shown attached to the outlet  13 . The regulator  14  weights about 6 ounces or less and has a diameter of about 1 inch with a length of about 3 inches. It is normally constructed of metal such as aluminum or steel due to the high pressures involved. An outlet  17  is provided on the side of the regulator  14  into which a female threaded pressure fitting  16  of conventional design is attached. The pressure fitting  16  has a quick connection so that a conventional air hose  18  can be readily attached thereto by means of a fitting  22  at one end of the hose. The other end of the air hose  18  would have a normally off valve female pressure fitting  24  thereon which is pushed onto the male pressure fitting  26  of the tool  20 . All pressure fittings and hoses are of conventional design and are commercially available. When the compressed gas is expended, the bottle  12  is unscrewed and replaced with a newly charged bottle. 
     Referring to  FIG. 2 , a cross sectional view of the compensating pressure regulator  14  is shown. It should be understood that the sizes, shapes, and placement of the various items are not limited, and merely shown to provide a picture of the general features of the present invention. References to “air” are understood to include fluids whether liquid or gas. Although threaded members are shown, other types of connections are feasible. 
     As seen in  FIG. 2 , the pressure regulator  14  has a body  30  with a threaded inlet  32  for accepting the bottle  12 . A pressure valve-actuating member  34  is located centrally in the inlet  32  on a top wall  36  of the inlet  32 . An inlet gas channel  38  is positioned also on the top wall  36 . A threaded outlet  40  is provided in the side  42  of the regulator  14 . Appropriate pressure fittings may be attached thereto. An adjustable cap member  44  is threaded into a threaded aperture  46  located at a top  48  of the regulator  14 . A slot  56  for adjustment of the cap member  44  is located on a top surface  58  of the cap member  44 . Although a slot for a screwdriver is shown, other types of structures may be placed thereon for use by machine or hand. A pressure relief vent, not shown, is also located in the cap member  44  to prevent over pressures beyond the design limit of the regulator  14 . The cap member  14  has a bottom recess  50  onto which a top  54  of a piston spring  52  is positioned. A bottom  60  of the piston spring  52  fits over a raised section  62 , shown in outline, of an upper piston  64  that is positioned in a pressure output chamber  66 . The upper piston  64  has a pressure o-ring  68  positioned thereabout to prevent the flow of gas about the upper piston  64  from the pressure output chamber  66 . A pin or rod-like holding device  70  is also located on a bottom  72  of the upper piston  64 . 
     A pin or rod  74  has an upper end  76  that is located in the pin holding device  70 . A lower end  78  of the pin  74  is connected to a lower piston  80 . The pin  74  slideably passes through an orifice structure  82 . The orifice structure  82  has a lower threaded section  84  that threads into an aperture  86  located in a bottom  88  of the pressure output chamber  66 . The orifice structure  82  has a plurality of gas orifices  90  that allow the gas to flow to the pressure output chamber  66  from an upper pressure chamber  92 . The upper pressure chamber  92  has a spring holding section  94  that has the lower piston  80  passing therethrough. A lower spring  98  positioned in the upper pressure chamber  92 /spring holding section  94  biases the lower piston  80  toward the pressure output chamber  66 . A gasket  100  is positioned on the top of the lower piston  80 . The lower piston  80  passes into a lower pressure chamber  102  and also has a pressure o-ring  104  positioned about the lower piston  80 . It should be understood that the o-ring  104  separates the lower pressure chamber  102  from the upper pressure chamber  92 . The inlet gas channel  38  inputs into the upper pressure chamber  92 . A compensating channel  106  is connected between the lower pressure chamber  102  and the pressure output chamber  66 . There is further no air seal between the lower piston  80  and the gasket  100  so that air flows past the gasket  100  into the chamber  93  above the gasket  100 . The volume of the chamber  93  determines the actual output pressure. If the adjustable cap member  44  is “unscrewed,” eventually, the gasket  100  will come into contact with a bottom  95  of the orifice structure  82  and thus prevent the flow of any gas through the orifices  90 . If the cap member  44  is “screwed” into the body a maximum amount, the volume of chamber  93  will increase and will allow the maximum air pressure output. 
     In normal operations where the gas pressure is stable, as gas flows into the inlet  32  from the attached bottle  12 , it enters the inlet gas channel  38 . It flows into the upper pressure chamber  92  of the lower piston  80  and then into the pressure output chamber  66 . It further flows into the compensating channel  106  to the lower pressure chamber  102 . The pressures upon the o-ring  104  will balance. 
     Considering a large input pressure spike from the attached container  12 , the higher pressure coming into the upper pressure chamber  92  will cause the lower piston  80  to move downwardly as seen in  FIG. 2 . The lower piston  80  dampening out spikes by quickly responding to pressure changes with the aid of seal  104 . Due to the larger mass of the upper piston  64  and the larger spring  52 , it will not respond as quickly as the lower piston  80  with spring  98 . The higher pressure will be transmitted through output chamber  66  enter into the compensating channel  106  to force the lower piston  80  upwards and further force the upper piston  64  upwards via the force from the pin  74  and thus decrease the pressure from the spike by increasing the volume of the pressure output chamber  66 . Thus, the spike in high gas pressure is compensated with the gas spike traveling through the compensating channel/path  106  thereby alleviating the pressure spike and returning the output gas pressure in chamber  66  to a preset state. 
     Considering a lower pressure spike, the lower pressure in the upper pressure chamber  92  will cause the lower piston  80  to move upwards and draws into the lower pressure chamber  102  gas from the pressure output chamber  66 . Further, the lower gas pressure will “tend” to cause the upper piston  64  to move downwards due to the discrepancy of spring forces between  52  and  98 . This differential will aid in decreasing the volume in the pressure output chamber  66 . The lower pressure spike will thus flow into the compensating channel  106  to causing the lower piston  80  to move downward down and to return to a stable condition as before the lower pressure spike. 
       FIG. 3  illustrates a cross sectional view of another embodiment of the compensating device. As seen therein, the gasket  100  of  FIG. 2  is replaced by an o-ring  122  in  FIG. 3 . A flange  110  is positioned at the top of the lower piston  80  and is integrally formed. A tapered pin section  114  merges with the flange  110 . An o-ring channel  112  is positioned about the lower part of the tapered pin section  114  so that the o-ring  122  is positioned therein. An upper edge  124  of the o-ring  122  will come into contact with an o-ring seat  120  formed about the bottom of the orifice structure  82 . An enlarged channel  126  has the orifices  118  positioned at the top thereof as well as a bore for slideably holding the pin  116 . When the o-ring  122  is pushed against the o-ring seat  120 , no air is allowed to flow past the flange  110  into the enlarged channel  126  and through the orifices  90  into the pressure output chamber  66 . 
     High or lower pressure spikes coming from the operating tool will be mitigated also by the compensating pressure regulator  14 . The higher pressure will cause the upper piston  64  to move upwards and the lower piston  80  to move upwards and thus lowering the resulting pressure in the pressure output chamber  66 . A lower pressure spike will cause the larger piston  64  to move downwards thus decreasing the available volume in the pressure output chamber thus equalizing any pressure variations whether high or low coming from the operating source or the compressed gas source. 
     Since many modifications, variations, and changes in detail can be made to the described embodiments of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents.