Abstract:
A bottle plate mates or is integrated with brackets for mounting a gas bottle atop the plate. An aft end of the bottle plate is spacedly affixed to a top of a base plate, the bottle plate being bendable about its aft end corresponding to the weight of a bottle mounted thereon. A plurality of guide pins disposed at a fore end of the bottle plate prevents lateral movement of the fore end with respect to the base plate, but allows to a limited extent displacement of the fore end due to bottle weight. Any displacement of the fore end due to bottle weight is converted to a corresponding bottle weight and a display indicates same to a user. The base plate is used to securely mount the apparatus.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to an apparatus for securely mounting a tank of compressed liquified gas in a vehicle and for continuously sensing and indicating the amount of liquified gas remaining in the tank. 
   While this invention is applicable in general to uses in which it is desirable to securely mount and continuously monitor the amount of a compressed liquified gas remaining in a tank, it is especially advantageous when used for mounting liquified nitrous oxide bottle tanks in racing vehicles. For example, bottle tanks containing liquified nitrous oxide are often securely mounted in the trunks of drag racing vehicles for piping the nitrous oxide to the vehicle&#39;s engine intake to boost horsepower and acceleration of the vehicle. In such cases, the nitrous oxide is stored under high pressure, typically around 900-1100 pounds per square inch (psi) for optimal performance, but as the gas in a bottle is used, the pressure can drop drastically and suddenly without warning. It is not uncommon for the pressure in a nitrous oxide bottle to suddenly drop to 600 psi or less when the bottle is running low (e.g., 1-2 lbs of gas remaining in a 10 lb. bottle), and at that point the nitrous oxide is no longer adding horsepower because the pressure of the remaining gas is below a typical threshold needed by a racing vehicle&#39;s intake system and the boost from the nitrous oxide starts cutting out. 
   Since the bottles must be very securely bolted into such racing vehicles, and since the only way of determining the amount of nitrous oxide remaining in a tank is to weigh it, drag racers especially are faced with a problem. Either they frequently unbolt their tanks and weigh them, which tends to be very time consuming, or they conservatively swap out nitrous oxide bottles before they are even half empty, typically after only five or six uses, based on estimating or guessing the amount of nitrous oxide remaining in a tank. Heretofore racers had no way of precisely knowing the amount of nitrous oxide remaining without removing the bottle and weighing it. 
   This invention takes the guesswork out of swapping tanks and eliminates the need to remove a bottle to weigh it; a racer can know precisely at any time the amount of liquified nitrous oxide remaining in a bottle without unbolting the tank and weighing it. This means that racers can reliably make more runs before swapping out bottles, which is a significant saving in time and money. Moreover, the advantages apply as well to racing boats that use nitrous oxide to boost horsepower and acceleration, and basically any vehicle in which a nitrous oxide bottle must be securely mounted. 
   Other advantages and attributes of this invention will be readily discernable upon a reading of the text hereinafter. 
   SUMMARY OF THE INVENTION 
   An object of this invention is to provide an apparatus for securely mounting and continuously monitoring the weight of a compressed liquified gas tank. 
   A further object of this invention is to provide an apparatus for securely mounting and continuously monitoring the weight of a nitrous oxide bottle tank within a vehicle. 
   A further object of this invention is to provide an apparatus for securely mounting and continuously monitoring the weight of a nitrous oxide bottle within a racing vehicle. 
   A further object of this invention is to provide an apparatus for securely mounting and continuously monitoring the weight of a nitrous oxide bottle within a racing vehicle&#39;s trunk. 
   These objects, and other objects expressed or implied in this document, are accomplished by an apparatus for mounting and continuously monitoring the weight of a liquified gas bottle including: a first plate; a bottle mount for affixing a bottle atop the first plate; a base plate, an aft end of the first plate being spacedly affixed to a top of the base plate, the first plate being bendable about its affixed aft end corresponding to the weight of a bottle mounted thereon; a plurality of guide pins disposed at a fore end of the first plate for preventing lateral movement of the fore end with respect to the base plate, but allowing to a limited extent displacement of the fore end due to bottle weight; and a device for converting any displacement of the fore end due to bottle weight to a corresponding bottle weight. Preferably the apparatus includes a display for indicating to a user the bottle weight. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side pictorial view of a liquified gas bottle mounted atop a preferred embodiment of this invention. 
       FIG. 2  is an opposite side pictorial view of the bottle mounted atop a preferred embodiment of this invention. 
       FIG. 3  is a partial pictorial view of a rear end of the bottle and mounting, and 
       FIG. 4  is a partial pictorial view of front end of the bottle and mounting. 
       FIG. 5  is a partial perspective view of a corner of this invention. 
       FIG. 6  is a partial perspective view further illustrating the operation of the preferred embodiment, particularly showing a tank full or near full. 
       FIGS. 7-9  are diagrammatical illustrations regarding the operation of the apparatus. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 1-3  and  5 , a bottle type compressed gas tank  2  is mounted atop a plate  4  by means of fore and aft mounting brackets,  8  and  6  respectively. As used herein, the terms “fore” and “aft” refer to the end of the invention at which a gas valve  10  of a mounted tank or bottle is located and the opposite end, respectively. Each of the brackets has a squared U-shape frame bolted to the plate, and supported by the upright legs of each bracket frame is a circular clamp,  12  and  14 , for securing the bottle to the brackets. As illustrated the fore bracket  8  supports the bottle  2  higher than bracket  6  causing the bottle to be forwardly inclined to keep the liquified gas at the bottom of the bottle where the outlet valve intake is located. Beneath the plate  4  upon which the bottle is mounted, i.e. the bottle plate, is a base plate  16 . The base plate is preferably the mechanical mounting interface between the apparatus of this invention as described herein and a vehicle in which or on which the structure is to be mounted. The aft end of the bottle plate is spacedly affixed atop an aft end of the base plate by means of bolts  18  and spacers  20 . Extending through holes defined by the bottle plate  4  at its fore end are two guide pins illustrated herein as bolts  22  with heads spaced above the bottle plate, and with threaded ends extending through holes defined by the base plate  16 . Sleeving each bolt  22  is a resilient, rubber or rubber-like sleeve  24  extending between the bolt&#39;s head and the bottle plate, and on each bolt is an axially concentric light coiled spring  26  disposed between the bottle plate and the base plate. Each bolt  22  is secured in relation to the base plate preferably by an engaging  23  nut beneath the base plate. The guide pins  22  restrict lateral movement of the bottle plate with respect to the base plate, but allow limited vertical movement of the fore end of the bottle plate with respect to the base plate. This allows the fore end of the bottle plate to flex toward and away from the base plate depending on the weight of the liquified gas in the bottle  2 . Adjacent to the corner of the bottle plate that is closest to the pivot pin  42 , a rubber or rubberlike bumper pad  27  is disposed between the bottle and base plates, spaced from the former and affixed to the latter. The pad acts to dampen extreme downward swings of the bottle plate  4  that can occur when the surface over which the vehicle is traveling is rough. 
   In use on a vehicle, the base plate  16  is securely affixed to the vehicle, for example by strong bolts. In the case of a racing vehicle the base plate is typically affixed to a trunk floor of the vehicle. The bottle is strongly secured to the base plate by the arrangement described above to withstand the various forces applied to it by acceleration, deceleration, and turning of the vehicle, and even though the bottle is securely in place, the bottle plate can nevertheless flex about a lateral axis defined by the aft bolts  18 , depending on the weight of the bottle which varies according to the amount of liquified gas contained therein. 
   Referring to  FIGS. 1 ,  2 ,  4 ,  7  and  8 , a device for converting the flexing of the bottle plate  4  to a corresponding indication of the amount of gas remaining in the bottle is illustrated. Spaced vertically above the base plate  16  by means of a bracket  32  is a potentiometer  34  having a pivoting wiper arm lever  36  connected to a cam  37  (illustrated as the shank of a screw connected to the lever  36 ) that is slidable in an axial slot  38  defined by an aft end of an elongated arm  40 . In this embodiment the potentiometer  34  is adjacent an upright leg of the bracket  6 . At its fore end the arm  40  is connected to a pivot pin  42  that is spaced above the bottle plate by a bracket  44 . Since the pivot pin is near the fore end of the bottle plate, it moves up and down corresponding to flexing of the bottle plate. A fore-wise extension  46  of the arm  40  extends beyond the arm&#39;s pivot axis. A counterweight  48  affixed to the arm&#39;s extension by a rod  49  biases the arm to pivot the arm&#39;s aft end upward (away from the base plate). Offset fore-wise from the arm&#39;s pivot axis is a vertical post  50  extending from the base plate. The head of the post  50  abuts the arm&#39;s extension  46  and, in operation, as the fore end of the bottle plate moves downward (toward the base plate) due to the bottle plate  4  bending in response to bottle weight (as best shown in  FIG. 8 ), the arm&#39;s extension  46  will react against the fixed post  50  causing the fore end of the arm  40  to pivot upward against the bias of the counterweight  48  and consequently causing the aft end of the arm to pivot downward. The greater the downward bend of the bottle plate, the greater the downward pivoting of the aft end of the arm, and correspondingly the lever  36  of the potentiometer will also pivot downward due to the cam  37  being confined in slot  38  of the arm. In response to the downward pivoting of the lever  36 , the potentiometer will produce a corresponding signal that drives a display or gauge that is preferably graduated and calibrated to indicate the weight of gas remaining in the bottle. In the preferred embodiment the gauge is an adapted automobile gasoline gauge. 
   In the preferred embodiment, the maximum flex displacement (bottle full) of the fore end of the bottle plate is only about 0.075 inches whereas the operational pivot range of wiper arm lever  36  is about 1.65 inches, much greater. The arm  40  serves to linearly amplify the flex displacement of the bottle plate fore end to a scale compatible with the wiper arm of the potentiometer. As illustrated in  FIGS. 8 and 9 , the length L 2  of the downward swing of the arm&#39;s aft end is essentially equal to the upward swing L 1  of the arm&#39;s fore end multiplied by the ratio of R 2  to R 1 . 
   It should be understood that the device for converting the flexing of the bottle plate to corresponding indications of the amount of liquified gas remaining in the bottle can be implemented differently than as described above. For example, strain gauges can be used to provide a signal corresponding to the flexure of the bottle plate in response to the changing weight of the gas in the bottle. 
   Referring to  FIGS. 1 and 5 , the apparatus can also include a tab  52  adjacent a side of the fore end of the bottle plate  4  with indicia, e.g., vertically spaced “E” and “F” facing outward to indicate whether the bottle is empty or full, respectively, or somewhere in between. As illustrated the “E” is at the same vertical height from the base plate as the bottle plate would be if it were empty, and the “F” is at the same vertical height from the base plate as the bottle plate would be if it were full. 
   Referring to  FIGS. 2 and 4 , the preferred embodiment further includes a shock absorber  56  to dampen and inhibit transient flexing of the bottle plate with respect to the base plate due to transient vertical acceleration of a vehicle incorporating the apparatus, for example, transients caused by bumps, pot holes and such that a vehicle may encounter. 
   Referring to  FIGS. 1 and 6 , the preferred embodiment further includes a compression spring  58  affixed to the base plate  16  below the aft end of arm  40 . This spring further biases the arm&#39;s aft end to pivot upward, away from the base plate, and in effect aids the bias applied by the counterweight  48  whenever the tank is full or near full. This spring helps overcome any resistance due to linkage sticking between the arm and the cam  37 , and any resistance of the potentiometer wiper arm  36 . 
   The foregoing description and drawings were given for illustrative purposes only, it being understood that the invention is not limited to the embodiments disclosed, but is intended to embrace any and all alternatives, equivalents, modifications and rearrangements of elements falling within the scope of the invention as defined by the following claims.