Abstract:
A deck gun elevator includes a tubular base, with an inlet, a longitudinal axis, and a transverse passage extending along the longitudinal axis, and a tubular member in the transverse passage, which forms an annular space between the tubular base and the tubular member. The tubular member includes an outlet, a longitudinal axis, and a transverse passage, which is in communication with the transverse passage of the tubular base for directing the flow of water through the deck gun elevator. A piston is mounted on the tubular member and positioned in the annular space and defines a first chamber, which is formed between the tubular member and the tubular base, and a second chamber, which is formed between the tubular member and the tubular base. A control controls the flow of fluid into and out of the first and second chambers to control the position of the tubular member along the longitudinal axis of the tubular base.

Description:
[0001]     This application claims priority to U.S. provisional application entitled DECK GUN ELEVATOR, Ser. No. 60/460,089, filed Apr. 3, 2003, which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD AND BACKGROUND OF THE INVENTION  
       [0002]     The present invention generally relates to an elevator and, more particularly, to a deck gun elevator for use on a fire truck.  
         [0003]     Most fire fighting deck guns are mounted on the deck of the fire truck in a fixed vertical position but with a swivel mount that permits the gun to be rotated. In addition, many deck guns include an articulating nozzle that pivots about one or more horizontal axes to adjust the reach of the gun.  
         [0004]     Some deck guns are mounted on an extensible pipe that is moved through a fixed outer tube using the water pressure running through the extension pipe; however, the control of the extension pipe is less than ideal.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides a deck gun elevator that adjusts the range of discharge of a deck gun by raising or lowering the deck gun and, further, adjusts the range of the deck gun in a controlled manner.  
         [0006]     In one form of the invention, a deck gun elevator, which is adapted for mounting on the deck of a fire fighting apparatus, includes a tubular base and a movable tubular member, which is positioned in the transverse passage of the tubular base and which includes a transverse passage in communication with the transverse passage of the tubular base for directing the flow of water through the deck gun. An annular space is provided between the tubular base and the movable tubular member. A piston is mounted on the movable tubular member and positioned in the annular space to define first and second chambers. A control controls the flow of fluid into and out of the first and second chambers to thereby control the position of the movable tubular member along the longitudinal axis of the tubular base.  
         [0007]     In one aspect, the control includes an actuator. The actuator has a cavity and a piston in the cavity, with the piston defining first and second chambers in the cavity. The first chamber of the actuator is in selective fluid communication with the first chamber between the tubular member and the tubular base. A second chamber of the actuator is in fluid communication with the second chamber between the tubular member and the tubular base.  
         [0008]     In a further aspect, the actuator includes at least one directional valve that controls the flow of fluid from the first chamber of the actuator to the first chamber between the tubular member and the tubular base. For example, the directional valve may comprise a solenoid valve.  
         [0009]     According to another aspect, the actuator further includes a valve for controlling direction of flow of the fluid between the second chamber of the actuator and the second chamber between the tubular member and the tubular base. For example, the valve for controlling the direction of flow may comprise a pilot check valve.  
         [0010]     In yet other aspects, the first chamber between the tubular member and the tubular base is filled with a first fluid, with the second chamber formed between the tubular member and the tubular base being filled with a second fluid. Preferably, the second fluid comprises an incompressible fluid, such as a hydraulic fluid. In a further aspect, the first fluid comprises air.  
         [0011]     It can be appreciate from the foregoing that the elevator of the present invention provides controlled adjustment of the extensible tube or pipe and, hence, of the deck gun mounted to the extensible pipe.  
         [0012]     These and other objects, advantages, purposes, and features of the invention will become more apparent from the study of the following description taken in conjunction with the drawings. 
     
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view of the deck gun elevator of the present invention illustrating the extensible pipe of the elevator in a retracted or home position;  
         [0014]      FIG. 2  is a similar view to  FIG. 1  illustrating the extensible pipe in a partially extended position;  
         [0015]      FIG. 3  is a similar view to  FIGS. 1 and 2  illustrating the extensible pipe in a fully extended position;  
         [0016]      FIG. 4  is a cross-section view taken along line IV-IV of  FIG. 1 ;  
         [0017]      FIG. 5  is an enlarged cross-section view of the end of the deck gun elevator of  FIG. 4 ;  
         [0018]      FIG. 6  is an enlarged cross-sectional view of the other end of the deck gun elevator of  FIG. 4 ;  
         [0019]      FIG. 7  is a schematic view of the control system of the deck gun elevator of the present invention;  
         [0020]      FIG. 8  is a perspective view of the actuator of the control system of the deck gun elevator of the present invention;  
         [0021]      FIG. 9  is a side elevation view of the actuator of  FIG. 8 ;  
         [0022]      FIG. 10  is a cross-section view taken along line X-X of  FIG. 9 ;  
         [0023]      FIG. 11  is a top plan view of the actuator of  FIG. 9 ;  
         [0024]      FIG. 12  is a cross-section view taken along line XII-XII of  FIG. 11 ; and  
         [0025]      FIG. 13  is a cross-section view taken along line XIII-XIII of  FIG. 11 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]     Referring to  FIG. 1 , the numeral  10  generally designates a deck gun elevator of the present invention. Deck gun elevator  10  is adapted to mount to the deck of a fire fighting apparatus and, further, adapted to mount a deck gun (not shown) to the deck. As will be more fully described below, elevator  10  raises and lowers the deck gun to adjust the range of the gun.  
         [0027]     Elevator  10  includes an extensible tube or pipe  12  that is extended or retracted into an outer tube or pipe  14  by a control system  16 , which increases the range and coverage of the deck gun, as will be understood by those skilled in the art. Extensible tube  12  includes an adapter  18 , which is adapted to mount the deck gun to the extensible tube  12 . Referring to  FIGS. 4 and 6 , adapter  18  comprises a cylindrical member  18   a  with a projecting annular flange  18   b  that inserts into the open end of extensible tube  12  and, further, is mounted to tube  12 , for example, with a threaded connection  18   e . Optionally and preferably, an annular seal  18   c , such as an O-ring seal, is positioned between the shoulder  18   d  of cylindrical member  18   a  and the inner surface of extensible member  12 .  
         [0028]     As best seen in  FIG. 4 , the proximate end of outer tube  14  includes an inlet adapter  20 , which adapts elevator  10  to be mounted to the deck of the fire fighting apparatus. As best seen in  FIG. 5 , inlet adapter  20  comprises a cylindrical member with an annular flange  20   a  for extending into the open end of outer tube  14 . Annular flange  20   a  is secured to outer tube  14 , for example, by a threaded connection and, further, includes one or more transverse passages  20   b  for communicating with the chamber formed between extensible tube  12  and outer tube  14 , as will be more fully described below.  
         [0029]     Positioned interiorly of outer tube  14  is an inner tube  22 , which is similarly mounted to inlet adapter  20 . For example, similar to outer tube  14 , inner tube  22  may be mounted to adapter  20  by a threaded connection  22   a . However, it can be appreciated, that tubes  14  and  22  may be fixedly mounted to adapter  20 , for example by welding. Extensible tube  12  is mounted over inner tube  22  in outer tube  14 .  
         [0030]     As best seen in  FIG. 5 , extensible tube  12  includes mounted thereon a piston  24  that seals against the inner surface  14   b  of outer tube  14  and, further, against the outer surface  22   b  of inner tube  22 . For example, piston  24  may include one or more seals, such O-rings or U-rings, for sealingly engaging the respective inner and outer surfaces of outer tube  14  and inner tube  22 . In the illustrated embodiment, piston  24  comprises an annular member  24   a  that is mounted on the proximate end of tube with an enlarged flange  24   b  that projects radially inward over distal end  12   a  of tube  12 . Flange  24   b  includes inner and outer annular grooves  24   c  and  24   d , with seals  24   e  and  24   f  positioned in grooves  24   c  and  24   d , respectively, for sealingly engaging inner surface  14   b  of outer tube  14  and outer surface  22   b  of inner tube  22 .  
         [0031]     As best seen in  FIG. 6 , an annular support collar  26  is mounted to distal end of outer tube  14 . Support collar  26  supports a ring bearing  28  through which extensible tube  12  extends for extension and contraction from outer tube  14 . Support  26  further includes an annular groove  26   a  with annular seal  30 , such as a U-cup seal, positioned in groove  26   a  for sealing against the outer surface of extensible tube  12 . In addition, support  26  includes a projecting flange  26   b  that extends into open end of outer tube  14  and is mounted therein by a threaded connection. Flange  26   b  forms an annular shoulder  32  that extends radially inward from outer tube  14  toward outer surface of extensible tube  12 . In this manner, the space between outer tube  14 , extensible tube  12 , piston  24 , and shoulder  32  forms a first chamber  34 . Similarly, the space between the shoulder  36  of inlet adapter  20 , outer tube  14 , and piston  24  (and hence extensible member  12 ) defines a second chamber  38  between outer tube  14 , extensible tube  12 , and inner tube  22 . It can be appreciated, therefore, that the position of extensible tube  12  can be controlled by the pressure in chambers  38  and  34 . To limit the extension of extensible tube  12  through outer tube  14 , extensible tube  12  optionally includes a stop  39 , such as a retaining ring, which abuts shoulder  32  of support  26  to define the fully extended position of extensible tube  12 . A stop may alternately be formed on piston  24 .  
         [0032]     Referring to  FIG. 7 , elevator  10  includes a control system  16  that controls the pressures in chambers  34  and  38  to control the extension and retraction of extensible tube  12 . Control system  16  includes an actuator  40  that mounts exteriorly of outer tube  14  and that controls the pressure in chambers  34  and  38  to thereby control the extension and retraction of extensible tube  12 . As best understood from  FIG. 10 , actuator  40  includes a generally closed body  42  with a cavity  44  and a piston  45  that divides cavity  44  into first and second chambers  46  and  48 , which are respectively in fluid communication with the first and second chambers  34  and  38  defined between the extensible tube  12  and outer tube  14 . In the illustrated embodiment, chamber  46  is in fluid communication with chamber  34  through a valve  52 , preferably a pilot check valve, which permits the flow of fluid from chamber  46  into chamber  34 , but which normally restricts the flow of fluid from chamber  34  into chamber  46 , as will be more fully described below. Chamber  48  is in selective fluid communication with second chamber  38  through one or more directional valves  54  and  56 . In the illustrated embodiment, chamber  48  is in fluid communication through valve  56  to an air system, such as a vehicle air system. Valve  56  is normally open so that the air system maintains the pressure in chamber  48  to maintain the pressure in chambers  46  and  34 . The fluid communication between chamber  38  and chamber  48  is controlled by direction valve  54 , which is normally in a closed configuration until actuated. For example, valves  54  and  56  preferably comprise solenoid valves, which are actuated by a control circuit  58 . Control circuit  58  includes a switch  60 , which is normally in an open position so that valves  54  and  56  are normally in a non-energized state until switch  60  is closed. As a result, extensible tube  12  is normally in a retracted position. When switch  60  is closed, solenoid valve  54  opens to permit fluid communication between chamber  48  and chamber  38 , which applies pressure to piston  24  and in turn which applies pressure to the fluid in chamber  34 . In addition, valve  54  is in fluid communication with valve  52 . When valve  54  is opened and pressure is applied to valve  52 , the flow of fluid through valve  52  is reversed from chamber  34  to chamber  46 . Thus, when valve  54  is actuated, fluid can flow from chamber  46  to chamber  34 , which permits extensible tube  12  to be moved to an extended position.  
         [0033]     In preferred form, the fluid in chamber  34  and chamber  46  comprises an incompressible fluid, such as a hydraulic fluid, while the fluid in chambers  38  and  48  preferably comprise a compressible fluid, such as air. In this manner, control system  16  may provide an “oil over air” control for extensible tube  12 . The oil over air control of the position extendible tube  12  is particularly suitable in high water pressure applications where the flow of water through the respective passageways of outer tube  14  and extensible tube  12  would normally exert sufficient pressure to extend extensible tube  12  through outer tube  14 . Since the fluid in chamber  34  is incompressible, despite the increase pressure due to the water flowing through passageway, extensible member  12  will not extend through outer tube  14  until the fluid in chamber  34  is discharged into actuator  40 , which only occurs when valve  54  is open.  
         [0034]     To return extensible member  12  to its retracted position, valve  54  is closed. When valve  54  closes, valve  52  will only permit the flow of fluid from chamber  46  to chamber  34  and the system pressure through valve  56  will increase the pressure in chamber  48  to thereby move piston  45  to urge the fluid in chamber  46  into chamber  34  to return extensible tube  12  to its retracted position, with the pressure in chamber  38  discharging through a vent  62  provided in valve  54 .  
         [0035]     Referring again to  FIGS. 10-13 , actuator  40  includes a cylindrical member  70  with end plates or caps  72  and  74  secured thereto to form closed body  42 . Both end plates carry annular seals for sealing cavity  44 . As previously noted, positioned in cavity  44  is a piston  45  that divides cavity  44  into chambers  46  and  48 , with chamber  46  for communicating with chamber  34  and chamber  48  for communicating with chamber  38 . Valve  52  is mounted to end plate  74  and is in communication with chamber  46  by a passage  78  formed in end plate  74 . Valve  52  in turn communicates with chamber  34  through a passage or opening formed in outer tube  14 . Valves  52  and  56  are similarly mount to end plate  74 , with valve  56  in communication with chamber  48  through a tube  80  that extends through end plate  74  and cavity  44  and through piston  45 . Tube  80  includes a passage  84  and one or more openings  82  to provide fluid communication between chamber  48  and valve  56 . Preferably piston  45  includes a seal such as an o-ring seal, for sealingly engaging the inner surface  70   a  of cylinder  70  and a seal, such as an o-ring seal, for sealing against tube  80 . In this manner, actuator provides a compact modular assembly that can be quickly mounted to outer tube  14  of elevator  10 . It should be understood that a control system incorporating separate components may also be used.  
         [0036]     While one form of the invention has been shown and described, other forms will now be apparent to those skilled in the art. Therefore, it will be understood that the embodiment shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention, which is defined by the claims, which follow as interpreted under the principles of patent law including the doctrine of equivalents.