Abstract:
Proper mounting of a motor vehicle fuel tank cap on a vehicle fill pipe is of major importance to reduce the vapors which on escaping from the fuel tank contributes to environ-mental pollution, to insure proper mounting of the gas cap there is provided in this invention apparatus and method for monitoring proper mounting of the motor vehicle fuel tank cap, on the fill pipe of the vehicle and the apparatus includes strain gauges, connected to a monitor computer and an alarm activated by the monitor computer to indicate proper or improper mounting of the fuel tank cap on the fill pipe of the vehicle fuel tank.

Description:
BACKGROUND OF THE INVENTION 
     This application filed per 37 CFR 1.53b(2)is a continuation-in-part of previous application Ser. No. 08/958,522 filed Oct. 27, 1997, now abandoned, having the same title and inventor, and is filed under 37 CFR 1.53b(2). 
    
    
     This invention is to disclose apparatus and method for monitoring motor vehicle fuel tank caps to insure adequate tightening of fuel/gas caps of motor vehicles, such as cars, trucks motorcycles etc. At the present time, particularly with self service gas stations, there is a problem of adequately tightening the fuel/gas cap after filling the fuel or gas tank. 
     When a fuel/gas cap is not adequately tightened, volatile components from the fuel or gasoline are vented out of the as tank past the cap and thus pollutes the atmosphere. 
     The gas cap monitor apparatus and method of this invention insures adequate tightening of the fuel/gas cap, after refueling,to prevent venting of vapors out of the gas tank, via the filler tube. By having adequate tightening of the vehicle fuel tank cap by the apparatus of this invention, as indicated by the monitor computer alarm of this apparatus, the atmosphere is protected from added pollution. 
     PRIOR ART IN THIS FIELD OF INVENTION 
     Prior art patents pertaining to this invention are; 
     U.S. Pat. No. 5,638,975 for LOST MOTION FUEL CAP WITH CLOSURE INDICATOR. A fuel cap including a closure mechanism and an indicator for providing indication of sealed closure of the cap on the filler tube. 
     U.S. Pat. No. 5,449,086 for DELAYED ACTUATION FUEL CAP. This patent discloses a fuel cap with a delayed actuation mechanism for providing a lost-motion driving connection between the handle of the cap and the housing. 
     U.S. Pat. No. 5,108,001 for PRESSURE RELEASE VENT CAP. This patent discloses a pressure relief and venting closure and includes provision of a torque over-ride for the closure to limit its rotary movement. 
     U.S. Pat. No. 4,765,505 for DELAYED ACTUATION FUEL CAP. Disclosure is made of a predetermined lost motion angle through which the handle and drive lug are permitted to rotate, relative to the driven lugs coupled to the closure. 
     U.S. Pat. No. 4,436,219 for SEALING CAP FOR A GASOLINE TANK. Disclosure is made of a gas cap and including an indicator window so one can read off the fully closed position of the sealing cap with certainty. 
     U.S. Pat. No. 4,280,346 for TORQUE OVERRIDE THREADED LOCKING CAP. Disclosure is made of a key locking cap for a threaded filler neck and provides for free ratcheting of the cap when locked. 
     U.S. Pat. No. 3,642,036 for AUTOMATIC FUELING FOR AUTOMOBILES Disclosure is made of a system for fueling a car by programmable means. 
     U.S. Pat. No. 5,671,786 for APPARATUS FOR AUTOMATIC REFUELING OF VEHICLES. Disclosure is made of apparatus for opening the fuel tank pipe of the vehicle and includes a robot head and a transceiver unit carried by the robot head. 
     SUMMARY OF THE INVENTION 
     This invention is to disclose apparatus and method for monitoring a motor vehicle fuel tank cap,to insure adequate tightening of the gas cap. A tight gas cap is to insure protection of the environment by preventing release of hydrocarbon fuel vapors from a refueled automobile filler pipe and past the gas cap. 
     The apparatus of this invention has a handle connected to a torsion plate cover which in turn fits over a bell shaped torsion plate and the torsion plate having side walls on the interior of the bell shaped torsion plate, and the side walls on the interior of the torsion plate forming channels across the inside diameter of the bell shape torsion plate and these channels to straddle the ridge of the gas cap to remove the gas cap on turning in a counter clockwise direction and further there is a gas cap ball head extending upward from the center of the fuel/gas cap ridge so that the gas cap is removed on unscrewing and the fuel/gas cap is held in the torsion plate by means of a gas cap clip extending over the gas cap ball head. 
     The torque indicating device mounted on torsion plate shaft pillars is in essence a wheatstone bridge with wires leading from strain gauge indicating device to contact rings then to the contact carrier and to a monitor computer alarm set to respond to a preset strain gauges “torque” measurement level to indicate suitable tightening of the gas cap after refueling. 
     Electric power is supplied to the monitor apparatus, which in turn supplies the power to the monitor computer alarm from the strain gauges indicating suitable fuel cap tightening on rotating the monitoring apparatus and fuel cap attached thereto on the fuel tank fill pipe. 
     The monitor computer alarm is set to respond audibly or visually at certain torque level, as indicated by the strain gauges, to indicate adequate closing of the vehicle fuel tank cap, or warning of failure to use,to adequately tighten the fuel tank cap onto the vehicle fill pipe. 
     OBJECTS OF THIS INVENTION 
     The monitor computer alarm is set to respond audibly or visually at a certain torque level to indicate placement and adequate closing of the fuel/gas cap, or warning of failure to adequately tighten the fuel/gas cap of the refueled automobile, or other vehicle. 
     An object of this invention of apparatus and method for monitoring motor vehicle fuel tank caps is to disclose apparatus, usable by hand, and comprising a torsion plate and channel walls in the torsion plate, and the channel walls providing channels in the torsion plate, and a torsion plate cover extending over the torsion plate, and the shaft of the torsion plate comprising torsion plate shaft pillars, and these pillars connected to the torsion plate shaft crown, and a strain gage mounted on each of the torsion plate shaft pillars, and the strain gages comprising a wheatstone bridge circuit, with wires extending from the strain gages to contact rings mounted inside of the torsion plate cover, and a wire from each strain gage connected to a separate one of the four contact rings, and the contact rings are insulated each from the other by means of insulating ring spacers. The electric wires from the strain gages are attached to the contact rings and for each contact ring there are contactor brushes making contact with its respective contact ring and the contactor brushes are mounted on contactor arms, and each contact ring has its own set of a pair of contact brushes mounted on its own set of contact arms, and a separate wire connected to each connector arm pair and the wire from each connector arm pair extends to a monitor computer alarm box wherein response is made as pre-set to respond to a limit of electrical response as relayed by the strain gages to torque developed on rotating clockwise by hand the handle of this fuel cap torque monitoring apparatus on tightening the vehicle fuel gas cap on the filler pipe of the fuel tank. 
     A further object of this invention is to disclose apparatus to limit the amount of torque applied on tightening the fuel cap on the filler pipe of the vehicle fuel tank, and the apparatus comprises a ratcheting or slipclutch arrangement for torque over ride protection between the base of the handle and the torsion plate to allow only a preset maximum torque to be attained for tightening the fuel gas cap and the slipclutch over-ride protects the strain gauge assembly from over-torque. 
     In this disclosure the strain gauges indicate the “torque” on rotating the vehicle fuel cap into the fuel pipe, and the monitor computer alarm is pre set to a predetermined value, from the strain gauges for suitable mounting of the fuel cap on the fill pipe of the fuel tank for a good seal of the cap on the fill pipe. 
     A further object of this invention is to disclose apparatus to limit the amount of torque applied on rotating the fuel gas cap on the filler pipe of the fuel tank, by means of a ratcheting arrangement between the base of the handle and the torsion plate to allow only a preset maximum torque to be attained on tightening the vehicle fuel tank cap onto the filler pipe of the fuel tank. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 Expanded view of assembly components of motor vehicle fuel tank cap monitor apparatus. 
     FIG. 2 Torsion plate. 
     FIG. 3 Automobile gas cap and ball top. 
     FIG. 4 Filler block. 
     FIG. 5 Bottom plan view of torsion plate bell section. 
     FIG. 6 Side view of torsion plate. 
     FIG. 7 Plan view of top of torsion plate. 
     FIG. 8 Elevation view of assembled gas cap monitor. 
     FIG. 9 comprising of FIGS. 9A,  9 B, and  9 C, is a view of the torsion plate cover. 
     FIG. 9A Plan view of bottom of torsion plate cover. 
     FIG. 9B Side view of torsion plate cover. 
     FIG. 9C Top plan view of torsion plate cover. 
     FIG. 10 comprising of FIGS. 10A and 10B, is a view of the lower contact ring spacer. 
     FIG. 10A Plan view of the lower contact ring spacer. 
     FIG. 10B Edge view of the lower contact ring spacer. 
     FIG. 11 comprising of FIGS. 11A and 11B, is a view of the contact ring. 
     FIG. 11A Plan view of the contact ring. 
     FIG. 11B Edge view of the contact ring. 
     FIG. 12 comprising, of FIGS. 12A and 12B, is a view of the contact ring spacer. 
     FIG. 12A Plan view of the contact ring spacer. 
     FIG. 12B Edge view of the contact ring spacer. 
     FIG. 13 comprising of FIGS. 13A and 3B, is a view of the lower seal. 
     FIG. 13A Plan view of the lower seal. 
     FIG. 13B Edge view of the lower seal. 
     FIG. 14 Slip ring housing bottom plan view. 
     FIG. 15 Slip ring housing, edge view. 
     FIG. 16 Slip ring housing elevational view. 
     FIG. 17 Slip ring housing top plan view. 
     FIG. 18 comprising of FIGS. 18A,  18 B, and  18 C, is a view of the upper seal ring. 
     FIG. 18A Upper seal ring top plan view. 
     FIG. 18B Upper seal ring bottom plan view. 
     FIG. 18C Edge view of upper seal ring. 
     FIG. 18A-A Enlarged view of upper seal ring. 
     FIG. 19 Elevational view of contact carrier wire harness. 
     FIG. 20 Isolated view of section of contact carrier. 
     FIG. 21 Isolated elevational view of contact carrier, contacts and contact rings. 
     FIG. 22 Isolated elevational view of section of contact carrier connections of wires to monitor. 
     FIG. 22B Plan view of contact carrier. 
     FIG. 23 Plan view of contact brushes, contact carrier and contact ring. 
     FIG. 24 Contact terminal end and side views. 
     FIG. 25A Enlarged section of the flex tongue of the slip ring cover housing. 
     FIG. 25B Top plan view of the slip ring cover housing. 
     FIG. 25C Elevation view of the slip ring cover housing. 
     FIG. 25D Bottom plan view of the slip ring cover housing. 
     FIG. 26A Front elevation view of the handle. 
     FIG. 26B Cross section view of the handle. 
     FIG. 27 Bottom plan view of handle. 
     FIG. 27A Top plan view of handle. 
     FIG. 27B Enlarged cross section of handle bottom drive ridges. 
     FIG. 28 Comprising of FIGS. 28A,  28 B, and  28 C, is a view of the handle end cap. 
     FIG. 28A Top view of the handle end cap. 
     FIG. 28B Side view of(the handle end cap. 
     FIG. 28C Side view of the handle end cap. 
     FIG. 29 Cover slip ring housing. 
     FIG. 29A Cross-section of the cover slip ring housing. 
     FIG. 29B Side view of the cover slip ring housing. 
     FIG. 29C Side view of the cover slip ring housing. 
     FIG. 30A Front elevation view of the gas cap clip. 
     FIG. 30B Edge view of the gas cap clip. 
     FIG. 31 Gas cap cover ball. 
     FIG. 32 Enlarged elevational view of gas cap held in gas cap clip. 
     FIG. 33 Elevational view of torsion plate. 
     FIG. 34 Wheatstone bridge circuit layout. 
     FIG. 35 Plan view B—B of torsion plate pillars showing strain gage contacts of wheatstone bridge. 
     FIG. 36 Expanded elevational view of connection of strain gage contacts to contact rings. 
     FIG. 37 Plan view of contact brushes mounted on contact carrier. 
     FIG. 38 Elevational segment view of contact carrier. 
     FIG. 39 Wire connection layout of gas cap monitor. 
     FIG. 40 Plan view of contact carrier and brushes and a contact ring. 
     FIG. 41 Enlarged elevational view of contact carrier in relation to contact rings. 
     FIG. 42 Comprising of FIGS. 42A and 42B is a view of the wire grommet. 
     FIG. 42A Edge view of the wire grommet. 
     FIG. 42B Plan view of the wire grommet. 
     FIG. 43 Elevational view of gas cap. 
     FIG. 44 Elevational view of section A—A of gas cap FIG.  43 . 
     FIG. 45 Magnified elevational view of meshing of flex tongue point and ridge cogs at base of handle. 
     FIG. 46 Assembled apparatus for monitoring motor vehicle fuel tank gas cap, in relation to fuel gas cap on filler pipe of vehicle fuel tank. 
     FIG. 47 Assembled apparatus for monitoring motor vehicle fuel tank cap, in contact with the fuel tank cap held in the torsion plate of the assembled apparatus. 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 LEGEND DESCRIPTIONS 
               
             
          
           
               
                 LEGEND # 
                 DESCRIPTION 
                 FIGURES 
               
               
                   
               
               
                  1 
                 Monitor box - Microprocessor or 
                 1, 34, 46 
               
               
                   
                 computer 
               
               
                  2 
                 Filler blocks 
                 4. 
               
               
                  3 
                 Torsion plate 
                 1, 2, 5, 6, 7, 36 
               
               
                  4 
                 Torsion plate cover 
                 1, 8, 9A, B, C. 46 
               
               
                  5 
                 Grommet for wires from torsion plate 
                 1, 42. 
               
               
                  6, 6′, 6″, 6′″ 
                 Contact ring spacers. 
                 1, 10, 36 
               
               
                  7, 7′, 7″, 7′″ 
                 Contact rings.(Brass silver plated) 
                 1, 11, 36 
               
               
                  8 
                 Top contact ring spacer. 
                 1, 12. 36 
               
               
                  9 
                 Lower seal 
                 1, 13, 
               
               
                 10 
                 Slip ring housing 
                 1, 8, 14, 15, 16, 
               
               
                   
                   
                 17. 29, 46 
               
               
                 11 
                 Upper seal 
                 1, 18 
               
               
                 12 
                 Contact wire carrier to monitor. 
                 1, 8, 19, 20, 21, 
               
               
                   
                   
                 22, 23, 46 
               
               
                 13 
                 Contact terminal 
                 21, 22, 24, 38, 
               
               
                   
                   
                 40, 41. 
               
               
                 14 
                 Cross bar of handle 
                 1, 8, 26A, B, 
               
               
                   
                   
                 27B, 46 
               
               
                 15 
                 Handle 
                 1, 8, 26, 27. 
               
               
                 16 
                 Handle end caps 
                 28. 
               
               
                 17 
                 Slip ring cover housing. 
                 25A, B, C, D, 25, 
               
               
                   
                   
                 29A, B, C. 
               
               
                 18 
                 Flex tongue point 
                 25A, 25B, 45. 
               
               
                 19 
                 Gas cap clip 
                 2, 30, 32. 
               
               
                 20 
                 Contactor brushes 
                 23, 37, 40. 
               
               
                 21 
                 Fuel cap top. 
                 3, 43, 44, 46. 
               
               
                 22 
                 Fuel cap ball. 
                 3, 31, 32, 46 
               
               
                 23 
                 Assembly screws 
                 1, 25C. 
               
               
                 24 
                 Torsion plate shaft pillars 
                 1, 6, 33, 35, 36. 
               
               
                 25 
                 Torsion plate shaft crown 
                 1, 6, 33, 36. 
               
               
                 26 
                 Monitor computer alarm 
                 1, 34, 39, 46 
               
               
                 27 
                 Electric power supply to system 
                 1, 34, 39. 
               
               
                 28 
                 Threaded openings in torsion plate 
                 1, 6, 
               
               
                   
                 crown for screws 23 
               
               
                 29 
                 Channel walls in torsion plate. 
                 5. 
               
               
                 30 
                 Channels in torsion plate 
                 5 
               
               
                 31 
                 Flex tongue 
                 25A 25B 
               
               
                 32 
                 Ridge cogs in base of handle; 
               
               
                   
                 (one ridge cog of a plurality) 
                 27, 27B, 45. 
               
               
                 33 
                 Base of handle 
                 1, 26A, B, 27A, 
               
               
                   
                   
                 27C, 46 
               
               
                 34 
                 Bundle of wires from strain 
                 36 
               
               
                   
                 gages of wheatstone bridge to 
               
               
                   
                 contact rings 
               
               
                 35 
                 Tension strain gages 35T1; 35T2; 
                 33, 34, 35 
               
               
                   
                 35T3; 35T4. 
               
               
                 35′ 
                 Compression Strain gages 35′C1; 
                 33, 34, 35 
               
               
                   
                 35′C2; 35′C3; 35′C4 
               
               
                 36 
                 Contactor arms. 
                 23, 37, 40 
               
               
                 37 
                 Assembled gas cap monitor apparatus 
                 8, 46 
               
               
                 38 
                 Vehicle fuel tank filler pipe 
                 31, 32, 46 
               
               
                 39 
                 Ridge of gas fuel cap. 
                 3, 43, 44, 46 
               
               
                 40 
                 Fuel tank cap 
                 43, 44 
               
               
                 41 
                 Notches on inside diameter of 
                 10 
               
               
                   
                 contact electrically insulating 
               
               
                   
                 spacers 
               
               
                 42 
                 Shoulder of shaft of slip ring 
                 1, 25 
               
               
                   
                 cover housing 
               
               
                 43 
                 Shaft of slip cover ring housing 
                 1, 25 
               
               
                 44 
                 Through holes for screw threads only 
                 1, 25C 
               
               
                   
                 of screws 23 to torsion plate crown 
               
               
                   
                 threads 
               
               
                 45 
                 Through holes in torsion plate 
                 9A, 9B, 9C 
               
               
                   
                 cover for screws 23. 
               
               
                 46 
                 Spaces between channels of torsion 
                 5 
               
               
                   
                 plate. 
               
               
                 47 
                 Flex snap arms of gas cap clip. 
                 3, 30, 32 
               
               
                 48 
                 Assembly of components of Fig. 1 
                 8, 46, 47 
               
               
                 49 
                 Contact ring inside diameter 
                 11A, 11B 
               
               
                   
                 strain gauge connector 
               
               
                 50 
                 Hub shaft of torsion plate cover 
                 1, 9B, 9C 
               
               
                 51 
                 D.C. electric supply. 
                 34 
               
               
                 52 
                 Splines on hub shaft of torsion 
                 9C 
               
               
                   
                 plate cover 
               
               
                 C1, C2, C3, C3 
                 Compression strain gages. 
                 33, 34, 35 
               
               
                 T1, T2, T3, T4 
                 Tension strain gages. 
                 33, 34, 35 
               
               
                   
               
             
          
         
       
     
    
    
     Bundle of wires to convey electrical/resistance charges, identified by color code: 
     R—Red 
     G—Green. 
     W—White. 
     B—Blue 
     These wires extend from strain gages on torsion plate pillars to contact rings to contact brushes to wires to monitor box to micro computer to signal audible or visual, or other response. 
     DETAILED DESCRIPTION OF INVENTION 
     The apparatus of vehicle fuel gas cap monitor and method of monitoring the vehicle fuel tank cap or “fuel/gas cap” is described as assembled gas cap monitor as shown in FIG. 8, and the component parts are as shown in FIG. 1, and this apparatus is usable by hand, by placing over the vehicle gas or fuel cap as shown in FIG. 46, then rotating or turning the handle counter clock wise to remove the gas cap  40  from the filler pipe  38  of the vehicle. The gas cap monitor apparatus includes a torsion plate  3  (FIGS. 2,  5 ,  6 ,  7 ) and in the bottom of the torsion plate  3 , there are channel walls  29  (FIG.  5 ), and these channel walls  29 , providing channels  30  (FIG. 5) in the bottom of the torsion plate  3 . These channels  30  are of sufficient width to straddle gas cap ridge  39  (FIGS. 43,  44 ,  46 ) on placing the assembled fuel/gas cap monitor apparatus  37  (FIG. 46) over the fuel/gas cap top  21  (FIGS. 43,  44 ,  46 ) on the fuel tank filler pipe  38 . Mounted over the torsion plate  3 , is a torsion plate cover  4  (FIGS. 1,  8 ,  9 A,  9 B,  9 C, and  46 ) and there are holes  45  as shown in FIG. 9C to allow the screws  23  to extend through and into threaded holes  28  in the crown  25  of the torsion plate shaft. Pillars  24 ,  24 ′,  24 ″ 24 ′″ (FIGS. 1,  6 ,  33 ,  35 ,  36 ) are attached to the torsion plate shaft crown  25 , (FIGS. 1,  6 ,  33 ,  36 ) and there is mounted on each torsion plate shaft pillar  24 , one compression strain gage  35  C 1 , mounted on torsion plate pillar  24 ,  35  C 2  mounted on torsion plate pillar  24 ′,  35  C 3  mounted on torsion plate pillar  24 ″ and  35  C 4  mounted on torsion plate pillar  24 ′″ and on each torsion shaft pillar  24  on the side opposite each compression strain gage there is mounted a strain gage indicating tension T 1 , T 2 , T 3 , T 4 , (FIGS. 33,  35 ,  36 ). 
     Mounted on torsion plate pillar  24  tension strain gage  35 T 1 ,  35 T 2  mounted on pillar  24 ′,  35 T 3  mounted on pillar  24 ″ and  35 T 4  mounted on pillar  24 ′″, (FIGS. 33,  35 ) The above mentioned pillars have a typical cross section dimension of for example, of about 0.055″×0.200″ with the 0.200″ dimension extending outward on a radius line, as shown in FIG. 35, and the strain gages C 1 -C 4  and Tension gages T 1 -T 4  are mounted on the sides of the long dimension in the direction of the radius line. In all of the above and following discussion, the word pertaining to “wire” or “wires” is meant to be for conductors of electrical signal. 
     Referring now to FIGS. 33,  34 , and  35 , wires are attached to the strain gage circuit, which wires are coded R—red, B—blue, G—green, and W—white as shown in FIG. 34, and these coded wires extend upward to contact rings  7 ,  7 ′,  7 ″ and  7 ′″ (see FIGS. 1,  9 B,  11 ) and the wires are connected to the contact rings as follows,  7 R,  7 ′B,  7 ″G,  7 ′″W. The contact rings  7 - 7 ″ are insulated electrically each from the other by means of contact ring spacers  6 ,  6 ′,  6 ″,  6 ′″ FIGS. 1,  10 ), and a top contact ring spacer  8  (FIG. 12) and a lower contact ring spacer  6 ′″, (FIGS. 1,  10 ) The above noted contact rings  7 - 7 ′″ and contact ring spacers  6 ,  6 ′,  6 ″,  6 ′″ are stacked on the shaft of the torsion plate cover  4  as shown in FIGS. 1, &amp;  10  Contact ring spacers  6 ,  6 ′,  6 ″,  6 ′″, as shown in FIG. 10, notches  41 , on the inside diameter of each, and are of electric insulative material, such as nylon. Mounted over the top contact ring spacer  8  is a lower seal  9 ,(FIGS. 1,  13 ) and serves to seal the bottom rim of slip ring housing  10  (FIGS. 1,  8 ,  14 ,  15 ,  16 ,  17 ,  46 ) onto the shoulder of torsion plate cover  4  (FIG.  1 ), thus covering the assembled contact rings connected to the wires as noted above. There is an upper seal  11  (FIGS. 1,  18 ) mounted on the top of slip ring housing  10  to fit between the slip ring housing  10  and the shoulder  42  of slip ring cover housing  17  (FIGS. 1,  25 A, B, C, D,  25 ,  29 A, B, C.). The shaft  43  of slip ring cover housing  17 , is fitted into the top of slip ring cover  10 , and holes are provided for insertion of screws  23  (FIGS. 1,  25 B, C, D) which screws will on assembly extend to threaded openings  45  in crown  25  of torsion plate  3 . The top opening of slip ring cover housing  17  (FIG. 25A 25 C,  25 B and  45 ) comprises flex tongues  31  and flex tongue points  18  having the shape of an equilateral or isosceles triangle, on the flex tongues  31 , and the tongues  31  concentric to the outer edge of the top opening of the slip ring cover housing. (see FIGS. 25A &amp; 45. 
     The bundle  34  of the four wires from strain gages of wheatstone bridge circuit as shown in FIGS. 1,  36 , extend from the strain gages C 1 , C 2 , C 3 , C 4  and T 1 , T 2 , T 3 , T 4  mounted on torsion plate shaft pillars  24 ,  24 ′,  24 ″ and  24 ′″ through a grommet  5  (FIG. 1,  42 ) in the torsion plate cover  4  and attached to electrically conductive contact rings  7 ,  7 ′,  7 ″,  7 ′″, preferably of silver plated brass. 
     The electric charge conveyed to the collector rings  7 - 7 ′″ by the wires R, G, W, and B bled off by  12  contact wire carrier to monitor, by means of contactor brushes  20 ,(FIG. 23) two of which are mounted on contactor arms  36  (FIGS. 36,  37 ,  38 ,  40 ,  41 ) and the contactor arms  36  are attached to a contact terminal  13 . There is a separate set of contactor brushes  20 , contactor arms  36 , and contact terminal  13 , as described above for each of collector ring  7 , 7 ′, 7 ″, 7 ′″, thus there are four contact terminals  13  (FIG. 24) of either brass or copper, and silver plated mounted on contact wire carrier  12  to monitor  1  and this contact wire carrier  12  to monitor  1  is mounted within the slip ring housing  10  and wires extend from the contact wire carrier  12  to a monitor box  1  (FIGS. 1,  34 ,  36 ,  19 ,  20 ,  21 ,  22 ) 
     Referring now to the handle  15 , of this gas cap monitor apparatus (FIGS. 26A,  26 B,  27 ,  27 A, and  27 B) the base of the handle  33  is to fit by a snap fit over the top of slip ring cover housing  17  and inside of the base  33  of the handle are ridge cogs  32  in base of the handle, and these ridge cogs  32  extend out on radius lines and further the ridge cogs  32  are in the shape of an equilateral or isosceles triangle in cross section elevation (FIGS. 27 b , &amp;  45 ) such that the side of ridge cog  32  meets the section of flex tongue point  18  which tongue point is in the shape of an equilateral or isosceles triangle to allow rotation in either clockwise direction. (see FIG. 45) Cross bar  14 , of the handle (FIGS. 26A,  26 B &amp;  27  &amp;  27 A) is to provide turning leverage of the assembled gas cap monitor  37 . 
     In order to prevent bypassing the use of the monitor filler blocks  2  (FIG. 4) can be mounted in spaces  46  in torsion plate  3 , which spaces  46  adjoin the channel walls  29  of the torsion plate  3 . 
     Handle end caps  16  (FIG. 28) molded of rubber material, may be mounted over cross bar  14  of the handle of the monitor assembly  37  for ease of handling. 
     Reference is now made to the fuel/gas cap of this invention, which is part of the apparatus and method for monitoring the fuel/gas cap to insure adequate tightening of the cap on vehicle refueling. The fuel/gas tank cap  40  (FIGS. 31,  43 ,  44 ) has a ridge  39 , on the top surface of the cap and mounted on top of this ridge is a fuel/gas cap ball  22 , and on placing the monitor assembly  37  over the gas cap  40  having the ridge  39  and ball  22 ,(see FIG. 46) the gas cap ball  22 , fits into the gas cap clip  19  and arms  47  of the gas cap clip  19  snap around the ball  22 , (see FIGS. 30,  32 ) and the gas cap ridge  39  fits into the channels  30  in torsion plate  3 , and the monitor assembly  37  turned counter-clockwise to remove the gas cap  40  and the gas cap is held in the monitor assembly by means of the gas cap clip  19 , while refueling,then after refueling the gas cap  40  held in the monitor assembly is placed on the fuel tank filler pipe  38  (FIG. 46) and the assembly is turned, rotated or revolved, by hand to adequately secure the fuel cap  40  onto the fuel tank filler pipe  38 . 
     This apparatus for monitoring motor vehicle fuel tank caps  40  for proper mounting on fuel filler pipe  38 , includes a monitor assembly  48  and strain gauges  35 ,  35 ′ mounted on torsion plate shaft pillars  24  of the torsion plate  3  in the monitor assembly  48 , and monitor computer  1  and alarm  26  responsive to output signals from the strain gauges  35 ,  35 ′ for generating a signal to the monitor computer alarm  26 . 
     The monitor computer alarm  26 , is shown in FIGS. 1,  34 ,  39 , and  46  as attached to the monitor box  1 , however the alarm  26  may be mounted away from the monitor box  1 , tethered and connected thereto by conductive wires as needed. 
     The electric power supply to the system  27 , may be a plug-in, to the electric supply, and a rectifier for D.C. current to the strain gauges or by a battery electric D.C. supply. 
     In this invention disclosure the term “gas cap” or “fuel/gas cap” have the same meaning as “motor vehicle fuel tank cap”, and are used interchangeably. 
     Contact rings  7 ,  7 ′,  7 ″, and  7 ′″ each have on the inside diameter a strain gauge wire mount  49 , for connection of wires from the strain gauges. 
     Contact ring spacers  6 ,  6 ′,  6 ″, and  6 ′″ each have notches  41  described as inside diameter notches, and these contact ring spacers  6 ,  6 ′,  6 ″, and  6 ′″ fit over the hub shaft  50  of torsion plate cover  4 , and the notches  41  fir over splines on the hub shaft  50 , and the spacers are of electrical insulative plastic material, such as nylon and similar material. 
     The mechanics of using the vehicle fuel tank cap apparatus of this invention is best described as a tool handled by the person filling a vehicle fuel tank, by grasping the handle  15  of the apparatus and placing over the fuel cap  40  (se FIG. 47) and rotating the apparatus counter clockwise and lifting the fuel cap  40  out of the fill pipe and the cap  40  is held in the apparatus. After refueling, the apparatus holding the fuel cap  40  is placed over the filler pipe  38  and rotated clockwise to tighten the fuel cap  40  as will be indicated by the monitor  1  and alarm  26  and electric power supply  27  tethered to the apparatus, and then removing the apparatus from the filler pipe and fuel cap. The alarm is to indicate inadequate tightening of the fuel cap  40 , on the filler pipe  38 .