Abstract:
A triple-CNG (Compressed Natural Gas) cylinder mounting device for a vehicle for mounting a single-gas cylinder placement unit ( 2 ) and a dual-gas cylinder placement unit ( 3 ) onto the vehicle frame ( 1 ) having a right frame member ( 11 ) and left frame member ( 12 ) partitioned by a front cross-member ( 13 ) and a rear cross member ( 14 ). The single-gas cylinder placement unit ( 2 ) is disposed at the front part of the vehicle frame ( 1 ). The single-gas cylinder placement unit ( 2 ) is locked by the locking means on the right frame member ( 11 ) and/or the left frame member ( 12 ) and/or at the front cross-member ( 13 ). While, the dual-gas cylinder placement unit ( 3 ) is disposed between the middle and rear parts of the vehicle frame ( 1 ). The dual-gas cylinder placement unit ( 3 ) is locked by the locking means on the frames ( 11 ) and/or ( 12 ) and optionally on the rear cross-member ( 14 ).

Description:
FIELD OF THE INVENTION 
     The invention is in the field of Mechanical Engineering relating to a CNG (Compressed Natural Gas) cylinder mounting device for a vehicle. 
     BACKGROUND OF THE INVENTION 
     The typical pickup truck with the installation of CNG system has two gas cylinders installed in relation with the amount of CNG that can be contained in the cylinders. Additionally, to install the system, it is required to remove the pickup bed to assemble the gas cylinder mounting device and to drill into the frame of the vehicle for fixing the device to the frame; thus causing difficulties in the parts assembly of the gas cylinder mounting device on the vehicle frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates the components of the vehicle frame and the placement location of the gas cylinder. 
         FIG. 2  illustrates a three-gas cylinder mounting device unit. 
         FIG. 3  illustrates a single gas cylinder placement supporting frame. 
         FIG. 4  illustrates the side components of the single gas cylinder placement supporting frame. 
         FIG. 5  illustrates the components used for the installation of the gas cylinder on the single-gas cylinder placement unit. 
         FIG. 6  illustrates the side components used for the installation of the gas cylinder on the single-gas cylinder placement unit. 
         FIG. 7  illustrates the parts assembly of the frame locking bracket unit used to fix the single-gas cylinder placement unit to the vehicle frame. 
         FIG. 8  illustrates a dual gas cylinder placement supporting frame. 
         FIG. 9  illustrates the top view of the dual gas cylinder placement supporting frame. 
         FIG. 10  illustrates the components used for the installation of the gas cylinder on the dual gas cylinder placement unit. 
         FIG. 11  illustrates the top view of the components used for the installation of the gas cylinder on the dual gas cylinder placement unit. 
         FIG. 12  illustrates the left rear cross-member locking unit. 
         FIG. 13  illustrates the right rear cross-member locking unit. 
         FIG. 14  illustrates the right frame locking unit. 
         FIG. 15  illustrates the assembly of the dual gas cylinder placement unit locking unit onto the vehicle frame. 
         FIG. 16  illustrates the device unit for the installation of both gas cylinder units onto the vehicle frame. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will now be described by way of example and with reference to the accompanying drawings in which: 
     The components used in reference to the invention of the three-CNG cylinder mounting device comprises a vehicle frame  1  and three gas cylinders  15 ,  16  and  17  whereas the vehicle frame is deemed as a starting point when considering the placement of each cylinder and a guideline for the invention of the gas cylinder mounting device. In summary, there are two gas cylinder mounting device units: a single gas cylinder placement unit  2  and a dual cylinder placement unit  3  whereas the single gas cylinder placement unit  2  and the dual cylinder placement unit  3  are assembled separately by each own method. The units have a feature of a cylinder placement frame to be pre-assembled and mount the gas cylinders  15 ,  16  and  17  before being taken to assemble on the vehicle frame  1 . The steps of the invention of the CNG cylinder mounting device are as below: 
     According to  FIGS. 1 and 2 , it illustrates the feature of the vehicle frame  1  and the placement location for the gas cylinder  15 ,  16  and  17  in reference to the following details: The vehicle frame comprises the right frame member  11 , the left frame member  12  and the front cross-member  13  whereas each of the first two has a feature of a two-piece plate with holes of different shape and size, folded to form a U shaped cross section joined together by means of fixing to form a steel bar with a square cross section as the right frame member  11 , the left frame member  12  extending along the vehicle body (not shown in the figure) and the front cross member  13  has a feature of two-piece plate with holes being through holes for fixing with the spot nuts  18  and is folded into a U shaped cross section. Other connection members may be used, consistent with the spirit of the invention. The two pieces are joined together by means of fixing and placed transversely on the right frame member  11  and the left frame at the front. The joined piece acts as a transverse beam and is fixed to the suspension system of the vehicle (not shown in the figure). The placement of the gas cylinders is divided into two parts: The placement of the single gas cylinder  15  and that of the dual gas cylinder  16  and  17  whereas the single gas cylinder  15  is placed parallel to the right frame member  11  as shown in  FIG. 1  and the single gas cylinder placement unit  2  is provided to mount this single gas cylinder onto the vehicle frame; the dual gas cylinder comprising the gas cylinders  16  and  17  is placed parallel to the rear cross member  14  whereas the rear cross member  14  is in between the gas cylinder  16  and  17  and the dual gas cylinder placement unit  3  is provided to mount the gas cylinder  16  and  17  onto the vehicle frame. 
     The Steps of the Invention of the Single CNG Cylinder Mounting Device with Details as Follows: 
     According to  FIGS. 3 and 4 , it illustrates the single-gas cylinder placement supporting frame  20  comprising the cylinder fastening belt supporting sheet  21  with an arch edge in relation to the radius of the gas cylinder  15  and through holes on the bottom thereof for fixing the left front member  23  and right front member  24 , in total of two, for supporting the gas cylinder  15 , are assembled with the lower cylinder fastening belt  22 A by means of fixing whereas the two ends of the lower cylinder fastening belt  22 A are perforated and fixed with spot nuts  18  at both ends of the perforated locations under the lower cylinder fastening belt  22 A. This single-gas cylinder placement supporting frame  20  is divided to support parts: the front and the back whereas there are provided the left front member  23  and the right front member  24  as a unit connecting between both cylinder placement units. The front part of the single-gas cylinder placement supporting frame  20  comprises the front bracket  25  with a feature of a plate folded into an L shape placed along the front of the single-gas cylinder placement supporting frame  20  whereas the front end is perforated for assembling to the left front member  23  by means of fixing and then orthogonally folded to the side wherein the side end has a feature of a flange fixed to the edge of the cylinder fastening belt supporting sheet  21  by means of fixing. Other locking bracket may be used, consistent with the spirit of the invention. On the flange, there is provided four through holes with spot nuts  18  fixed inside on the four through holes for locking with bolts  19  to fix the single gas cylinder placement supporting frame  20  to the right frame member  11  as in  FIG. 4 . Other connection members may be used, consistent with the spirit of the invention. The positions of the two fixing holes are on the top of the flange. A bolt  19  is used to fix and lean against the top of the right frame member  11  (not shown) in the middle line of the flange at one hole whereas the bolt  19  is fixed through the right frame member  11  (not shown) and on the bottom of the flange, a bolt  19  is inserted through under the right frame member  11  (not shown) the other hole. The details on the assembly to the vehicle frame  1  will be explained in later steps. On the outside of the front bracket  25 , there is provided an inside frame supporting sheet  28  with a contact surface next to the front bracket  25  along the side length and being fixed together by means of fixing. At the front of the front bracket  25 , there is provided an counter-slider supporting bracket  30  having a feature of an angle plate with two holes for inserting bolts  19  and two spot nuts  18  next to the bottom of the through holes acting as a stopper holder (not shown) for setting the distance of the single gas cylinder  15 . On the back, there are provided two gas cylinder supporting sheets  21  assembled with the lower cylinder fastening belt  22 A with two spot nuts  18  fixed there under at the two ends of the lower cylinder fastening belt  22 A on both sides by means of fixing. Then the assembled rear cylinder placement unit is assembled with the left front member  23  and the right front member  24  by means of fixing to support the single gas cylinder  15  at the back. Thereafter, the flange is fixed with right frame member  11  comprising inner rear bracket  27  having a feature of two bolt through holes plate  19  with two spot nuts fixed on the through holes whereas the positions of the holes is on the outer edge of the right frame member  11  on both the upper and lower. Other locking bracket may be used, consistent with the spirit of the invention. The middle line of the inner rear bracket  27  is perforated and inserted with the position locking pintle  34 A for locating the assembly of the single-gas cylinder placement with the vehicle frame  1 . The inner rear bracket  27  and gas cylinder supporting sheet  21  are assembled together by means of fixing. The inner rear frame supporting sheet  29  and the position locking pintle  34  are assembled with the inner rear bracket  27  by means of fixing. Then the rear sheet  26  fixed with the counter slider  31 A is assembled with the left front member  23  and the right front member  24  by means of fixing. After that, two of the three cylinder covering brackets  33  are fixed with front bracket  25  and one of that is fixed with the rear bracket  26  by means of fixing. 
     According to  FIGS. 5 and 6 , it illustrates the installation of the gas cylinder unit onto the vehicle frame  1 . The single-gas cylinder covering sheet  35 A and the valve head separator  36 A are assembled together by means of fixing to prevent the impact on the gas cylinder  15  (not shown) and cylinder head valve (not shown) whereas the elements are assembled with the single gas cylinder placement supporting frame  20  at the bottom using bolts  19 . The counter slider  37 A is assembled with the counter slider supporting bracket  30  together with the counter sliding rubber cover  38  as to lock the position of the gas cylinder placement (not shown) and assembled with the counter sliding rubber  38  on the counter slider  31 A fixed to the rear sheet  26  for the preparation of the gas cylinder placement  15  (not shown). In the next steps, the upper cross member locking bracket leg  41 , the upper cross member locking bracket  42  with a number of spot nuts  18  and the upper cross member supporting sheet  43  are assembled together by means of fixing into the single cross member locking unit and the cylinder fastening belt supporting rubber  39 A is assembled with the lower cylinder fastening belt  22 A at both the front and the back and the upper cylinder fastening belt  40 A at both the front and the back. 
     The Assembly of the Gas Cylinder Mounting Unit with the Vehicle Frame 
     The gas cylinder  15  (not shown) is placed between the front and the back of the lower cylinder fastening belt  22 A whereas the counter slider supporting bracket  30  is used to determine the rear contacting distance. When the gas cylinder  15  (not shown) is placed, the counter slider  37 A is assembled wherein the face of the counter sliding rubber  38  contact against the front of face of the gas cylinder  15  (not shown). Then two bolts  19  are fixed thereto to lock the position of the gas cylinder preventing it from moving. The gas cylinder  15  (not shown) is locked using the upper cylinder fastening belt  40 A assembled with the cylinder fastening belt locking bracket  32 A at both ends by means of the fixing and put upon the gas cylinder  15  using bolts  19  to tighten it between the upper cylinder fastening belt  40 A and the lower cylinder fastening belt  22 A at both the front and the back to lock the gas cylinder  15  (not shown) and prevent it from moving. Then the single-gas cylinder placement unit  2  with the installation of the gas cylinder (not shown) by putting it up from below the vehicle without removing the vehicle bed (not shown) is lifted whereas the upper cross member locking bracket  42  is lifted to hook on the front cross member  13 . Then the single-gas cylinder placement supporting frame  20  is moved in such a way that the inner rear frame supporting sheet  29  and the inner front frame supporting sheet  28  are contacted with the inside of the right frame member  11  whereas the position locking pintle  34 A is inserted into the hole inside the right frame member  11 . Subsequently, the single-gas cylinder placement supporting frame  20  is locked with the vehicle frame at each spot. 
     The Assembly of the Locking Unit for the Single-Gas Cylinder Placement Unit with the Vehicle Frame has Details as Follows: 
     According to  FIGS. 6 and 7 , on the inner right front position, there are provided main components: the front bracket  25  having a feature of a plate with edges cut and folded orthogonally in relation to the position of the assembly into an L shape whereas the end of the front is perforated for fitting on the left front member  23 . The right side end is a flange with three bolt through holes  19  having spot nuts  18  fixed through all three holes. The inner front frame supporting sheet  28  has a feature of a flat plate with a bolt through holes  19  and a spot nut also fixed through the hole. The outer right front unit comprises the outer front frame supporting sheet  49  with a bolt through hole  19  and the outer front bracket  50  having four screw through holes  19  whereas both sheets are assembled together as such the holes are aligned in the middle line of both sheets and fixed to one another by means of fixing, and is assembled with the outer right front frame member  11 . Other free locking bracket may be used, consistent with the spirit of the invention. Later, two of the three frame locking sleeves  46 A are inserted between the front bracket  25  and the outer front bracket  50  at the top of the right frame member  11  and the remaining sleeve is at the back as such the holes of all three elements are aligned. Then the bolts  19  are inserted through the holes of the outer front bracket  50 , the frame locking sleeves  46 A and the front bracket  25  and tightened them with the spot nuts  18  fixed to the front bracket  25 . Subsequently, another bolt  19  is inserted through the hole in the middle of the outer front bracket  50 , the outer front frame supporting sheet  49 , the right frame member  11  and the inner front frame supporting sheet  28  and then is tightened to the spot nut  18  fixed to the inner front frame supporting sheet  28  to end the steps of assembling the right front frame locking unit. 
     According to  FIGS. 6 and 7 , it illustrates the inner right rear position of the frame of the main components: the inner rear bracket  27  having a feature of a plate having two bolt through holes  19  together with two spot nuts  18  fixed on the same position as that of the through holes, and another through hole for assembled with the position locking pintle  34 A. Later, the inner rear frame supporting sheet  29  with a through hole for assembling with the position locking pintle  34 A is assembled with the inner rear bracket  27  whereas the positions of the holes of both position locking pintles  34 A are aligned. Subsequently, the position locking pintles  34 A are assembled with the holes and fixed them together by means of fixing. When the assembly if finished, the unit is then assembled with the back of the gas cylinder placement sheet  21  whereas the flange of the inner rear frame fixing sheet  27  is joined with the gas cylinder supporting sheet  21  by means of fixing. The outside of the right frame member  11  comprises the outer rear bracket  48 A with two bolt through holes  19  fixed on the outer rear supporting sheet  47 A by means of fixing. Other free locking bracket may be used, consistent with the spirit of the invention. Then with the outer rear supporting sheet  47 A is joined with the right frame member  11  on the outer tab, the back of the outer locking unit and frame sleeve  46 A are inserted between the inner rear bracket  27  and the outer rear bracket  48 A on both the upper and the lower parts of the right frame member  11  whereas the positions of the holes of the three components are aligned. Later, two bolts  19  are inserted through the holes of the outer rear bracket  48 A, the frame locking sleeve  46 A and the inner rear bracket  27  and then tightened with the two spot nuts  18  to end the steps of the assembly of the right rear frame locking unit. 
     The Position of the Cross Member Locking Unit has the Details and the Steps of the Assembly as Follows: 
     The front cross member  13  has a feature of the plates folded into a U shape, assembled and fixed together by means of fixing and provided with a rectangular cross section with two through holes on the upper and one through hole of the lower parts wherein the spot nut  18  is fixed inside (not shown). The upper cross member locking bracket  42  has a feature of a plate folded into a U shape, having two bolt through holes  19  and one spot nut  18  fixed on the outside while the inside is assembled with the upper cross member supporting sheet  43  and the front cross member  13  whereas the position of the through holes of both components are aligned to allow the bolts  19  to go through. Then the first bolt  19  is fixed by inserting through the holes of the upper cross member locking bracket  42 , the upper cross member supporting sheet  43  and the front cross member  13  and tightened with spot nuts  18  (not shown) fixed inside the front cross member  13 . Later, the lower cross member locking bracket  45  having a feature of a plate folded into a U shape with a bolt through holes  19  is fixed with the lower locking bracket supporting sheet  44  also having the through hole by means of fixing and then covers the bottom of the front cross member  13  whereas the positions of the through holes of both components are aligned. Other free locking bracket may be used, consistent with the spirit of the invention. Subsequently the bolts  19  are inserted from the bottom to the top through the holes of the lower cross member locking bracket  45 , the lower locking bracket supporting sheet  44 , the front cross member  13 , the upper cross member supporting sheet  43  and the upper cross member locking bracket  42  and tightened with spot nuts  18  fixed on the upper cross member locking bracket  42  to end the method of the invention of the single-gas cylinder placement unit mounting device on the vehicle frame. 
     The Steps of the Invention of the Dual CNG Cylinder Mounting Device are Detailed as Follows: 
     According to  FIGS. 8 and 9 , it illustrates the dual gas cylinder placement supporting frame  60  comprising the front member  61 , the middle member  62  and the rear member  63  whereas the length of the front member  61  and the middle member  62  are the same but shorter than the rear member. All members are arranged parallel to one another as in  FIG. 8  whereas the left bracket  64  is assembled with the end of the front member  61  and the middle member  62  on the left and the right member  65  is assembled with the end of the front member  61  and the middle member  62  on the right. The rear member  63  having the length longer than the length of the end will eventually have the average length as same when assembled with the left bracket  64  and the right bracket  65  whereas all the mentioned components namely the front member  61 , the middle member  62 , the rear member  63 , the left bracket  64  and the right bracket  65  will assembled altogether as the gas cylinder placement frame  15 ,  17  by means of fixing. Upon the completion of the gas cylinder placement frame, the sub-brackets are assembled as follows: the front sub-bracket  61  having a feature of a plate is perforated as a screw through hole  19  on the middle line and on the end with an edge cut in relation to the curve of the radius of the front member  61 , folded into a U shape and then fixed with spot nut  18  inside on the through hole where two front sub-brackets  68  are joined to the front bracket  61  by means of fixing as to support the lower cylinder fastening belt  22 B (not shown) and to tighten the gas cylinder  16  with the upper cylinder fastening belt  40 B (not shown). The middle bracket having a feature of a plate, with two bolt through holes  19  and the side edge cut into a curve in relation with the radius of the middle member  62 , folded into a U shaped wing and then fixed with two spot nuts  18  on the inside of the two through holes is made into two sub-brackets assembled with the middle member  62  by means of fixing as to support the lower cylinder fastening belt  22 B and to fix the gas cylinder  16  and  17  to the upper cylinder fastening belt  40 B. The rear sub-bracket  70  having a feature of a plate with a bolt through hole  19  on the middle line and on the end cut into an edge with a curve in relation to the radius of the rear member  63  and folded into a U shape and fixed with spot nut  18  on the inside of the through hole. The two rear sub-bracket  70  are assembled with the rear member  63  by means of fixing as to support the lower cylinder fastening belt  22 B and to fix the gas cylinder  17  to the upper cylinder fastening belt  40 B. On the left, the end of the rear member  63  is assembled with the outer left frame locking sheet  67  and on the right, it is assembled with the outer right frame locking sheet  66  by means of fixing as to fix the dual gas cylinder placement supporting frame  60  to the left frame member  12  and the right frame member  11 . Other locking bracket may be used, consistent with the spirit of the invention. The left bracket  64  and the right bracket  65  has a feature of a plate with a lower edge folded orthogonally into a wing being a flange for assembling the dual cylinder covering sheet  35 B onto the bottom and the perforation on the flange is made into three through holes for the bolts  19 . The spot nuts are fixed on the top of the three through holes as to fix the bolts  19  for locking the dual cylinder covering sheet  35 B, the valve head separator  36 B and  36 C. On the front of the left bracket  64  and the right bracket  65 , there are provided through holes for fixing to the front member  61  at the front position the middle  62 , the middle position of the rear member  63 , the rear position between the fixing points of the front member  61  and the middle member  62  is perforated into two bolt through holes and in between the fixing points of the middle member  62  and the rear member  63 , there are provided two slots whereas the left bracket  64  and the right bracket  65  have the same feature. However when they are assembled into a dual gas cylinder placement supporting frame  60 , the inside of the left bracket  64  is fixed with the spot nuts at the two bolt through holes  19  as to fix the left sub-cross member bracket  71  (not shown) and in between the inside of the front member  61  and the middle member  62  and the rear member  63  is fixed with a counter slider  31 A each for set the placement position of the gas cylinder  16  and  17  (not shown). Both the spot nut  18  and the counter slider  31 A are assembled with the left bracket  64  by means of fixing. The right bracket  65  at the bolt through holes  19  between the fixing points of the inside of the front member  61  and the middle member  62  are fixed with two spot nuts  18  by means of fixing as to fix the inner frame supporting bracket leg  84  (not shown). 
     The Assembly of the Gas Cylinder  16  and  17  with the Dual Gas Cylinder Placement Unit 
     According to  FIGS. 9 ,  10  and  11 , upon the assembly of the dual gas cylinder placement supporting frame  60 , the following steps are the assembly of the gas cylinder mounting device  16  and  17 : the dual cylinder covering sheet  35 B is assembled with the dual gas cylinder placement supporting frame  60  at the bottom by fixing bolts  19  at the front, the middle and the back to three spot nuts  18  on the flange of the right bracket  65  before locking the flange of the left bracket  64  only at the middle position with the spot nuts  18  on the flange of the left bracket  64 . Subsequently, the valve head separators  36 B and  36 C are assembled with the dual cylinder covering sheet  35 B whereas the valve head separator  36 B having a feature of a plate folded to an angle on the bottom is folded into a flange for assembled with the dual cylinder covering sheet  35 B and perforated for a bolt through hole  19  at the front position of the left bracket and then bolts  19  is inserted through the top to fix with the spot nut  18  at the front of the left bracket flange  64  and tightened. The valve separator  36 C having a plate folded to an angle and perforated for a bolt through hole  19  on the flange assembled with the dual cylinder covering sheet  35 B is assembled with the dual cylinder covering sheet  35 B at the bottom position of the rear left bracket  64  and the bolt  19  is used to tightened as in the case of the valve head separator  36 B. Subsequently, the counter slider rubber  38  is assembled with the two counter sliders  31 A and the gas cylinder fastening belt supporting rubber  39 B is assembled with all four lower cylinder fastening belts  22 B. Upon the assembly of the supporting rubber at all six spots, both gas cylinder  16  and  17  (not shown) are placed between the lower cylinder fastening belts  22 B of each part. Upon the placement of the gas cylinder  16  and  17  (not shown), both cylinders are moved to the left bracket  64  as to allow the gas cylinder  16  and  17  (not shown) contact with the two counter sliding rubber face  38  covering the counter slider  31 A to complete the steps for locating the placement position of the gas cylinders  16  and  17 . The four upper cylinder fastening belts  40 B are assembled with the four gas cylinder fastening belt supporting rubbers  39 B and cover them onto the gas cylinders  16  and  17  (not shown) whereas the positions of the bolt through holes  19  of the upper cylinder fastening belt  40 B and the lower cylinder fastening belt  22 B are aligned. Then the bolts  19  are assembled on the cylinder fastening belt bracket  32 B and locked with the two spot nuts  18  at the bottom of the lower flange of the middle sub-bracket  69  at the front on both left and right whereas the flange of the lower cylinder fastening  22 B and the flange of the cylinder fastening belt locking bracket  32 B are completely attached. Upon locking, bolts  19  are used for fixing the cylinder fastening belt locking bracket  32 B to the lower cylinder fastening belt  22 B at the position of the lower member  63  at two spots whereas the locking fashion is the same as that of the position of the middle sub-bracket  69  at the front. The locking fashion of the cylinder fastening belt locking bracket  32 B to the flange of the lower cylinder fastening belt  22 B at all four spots is the locking of the upper cylinder fastening belt  40 B to the dual gas cylinder placement supporting frame  60  before locking the upper cylinder fastening belt  40 B as to lock the gas cylinders  16  and  17  to the dual gas cylinder placement supporting frame  60  at another 4 spots whereas it relates the mounting procedure wherein the steps of fixing the upper cylinder fastening belt  40 B at the left and right positions of the front member  61  and at the positions of the middle member  62  at the back on both left and right for all four spots are as follows: the bolt  19  are inserted through the holes of the cylinder fastening locking bracket  32 B and the upper cylinder fastening belt  40 B and then the locking nut  18 B is assembled with the bolt  19  whereas the locking nut  18 B acts as the counter loosen unit of the bolt  19  when subject to the vibration. Subsequently the bolt  19  is pushed into the holes of the front bracket  68  and the middle bracket  69  at the back to tighten and fix it onto the spot nut  18  fixed on the bottom of the through holes of the front sub-bracket  68  and the middle sub-bracket  69  and then the locking nut  18 B is tightened with the front sub-bracket  68  and the middle sub-bracket  69  at all four spots on the top to prevent the bolts  19  from being loosened. 
     The Assembly of the Dual Cylinder Placement Unit Mounting Device Unit with the Vehicle Frame 
     According to  FIGS. 12 ,  13  and  14 , upon the assembly of the gas cylinder  16 ,  17  onto the dual gas cylinder placement supporting frame  60 , the installation device used to fix on three main spots between the dual gas cylinder placement supporting frame  60  and the vehicle frame  1  is assembled as follows: at the first spot, on the position on the left of the dual gas cylinder placement supporting frame  60 , there is provided a dual cylinder placement locking unit  60  fixed to the vehicle frame  1  called the left rear cross member locking unit SL 1  whereas this device unit is fixed with the rear cross member  14  on the left comprising different parts and the assembling steps are as follows: the left cross member bracket  71  having a feature of a plate of which the lower part is a flange with two through holes for the bolts  19  to go through whereas this flange is used to fix with the left bracket  64  (not shown). Other locking bracket may be used, consistent with the spirit of the invention. The middle line of the left sub-cross bracket  71  is provided with the left reinforcing bracket  74  with a feature of a plate folded orthogonally, fixed with the body of the left sub-cross bracket  71  by means of fixing. The upper end of the left sub-cross bracket  71  is fixed with the left cross member locking bracket  72  by means of fixing whereas the left cross member locking bracket  72  has a feature of a plate folded into a U shape whereas the wing of the U shape is tilted in relation to the position of the position of the assembly of the rear cross member  14  and the left rear cross member locking bracket  72  is provided with two through holes whereas one hole acts as a bolt through hole  19  with a spot nut  18  fixed on the top while another hole is for hiding the electric wire unit (not shown) as to complete the preparation of the left rear cross member locking unit SL 1 ; at the second spot, the right position of the dual cylinder placement supporting frame  60 , there is provided the device unit fixed with the rear cross member  14  on the right called the right cross member locking unit SL 2  comprising different parts and the assembling steps are as follows: the right sub-cross bracket  76  having a feature of a plate folded into a shape whereas the lower end is a flange with two through holes and two spot nuts  18  fixed thereon. Other locking bracket may be used, consistent with the spirit of the invention. At the position of the through holes, this flange is assembled with the right bracket  65  (not shown). The middle line of the right sub-cross bracket  76  is projecting upward and the upper end is folded orthogonally whereas the end of the flange is fixed to the right cross member locking bracket  77  by means of fixing wherein the right rear cross member locking bracket  77  has features and sub-component parts as same as those of the left side with a difference in the directions that are opposite to one another. On the upper part of the right sub-cross bracket  76 , there is provided the right reinforcing bracket  78  being a assembled plate folded orthogonally that is fixed by means of fixing to complete the preparation of the right rear cross member locking unit SL 2 ; and at the third spot, the right position of the dual gas cylinder placement supporting frame  60 , there is provided the right side frame locking unit SL 3  as a mounting device used to fix the dual gas cylinder supporting frame  60  to the vehicle frame  1  at the right frame member  11  whereas this device unit is called the right side frame locking unit SL 3  having the assembling steps and component parts as follows: the inner frame supporting bracket  83  has a feature of the plate having the laying line next to the right bracket  65  whereas the lower end has a feature of a flange with two bolt through holes  19  while on another end, the plate is laid upward to the top vertically and folded orthogonally on its sides along the vertical line to reinforce the bracket and the upper end is assembled with the inner frame locking bracket  84  having a feature of a plate folded into a shape of a U shaped cross section with three through holes whereas the upper holes and the lower holes have two spot nuts  18  assembled inside of the bracket. At the middle hole, the locking nut  34 B is fixed as in the same fashion by means of fixing as to set the placement position of the dual gas cylinder placement supporting frame  60  for the installation onto the vehicle frame. Other locking bracket may be used, consistent with the spirit of the invention. Subsequently, the inner frame locking bracket  84  previously assembled with the spot nut  18  and the position locking pintle  34 B is assembled with the inner frame supporting bracket leg  83  by means of fixing. Then the inner frame supporting bracket  85  featuring a plate folded orthogonally into a L shape with a locking pintle through hole  34 B is assembled with the inner frame locking bracket  84  whereas the through hole of the inner frame supporting bracket  85  is inserted into the locking pintle  34 B and then fixed to one another by means of fixing to complete the preparation of the mounting device at the third position. 
     According to  FIG. 15 , upon the preparation of the holding unit between the dual cylinder placement supporting frame  60  and the vehicle frame  1  comprising the left rear cross member locking unit SL 1 , the right cross member locking unit SL 2  and the right side frame locking unit SL 3  whereas both of the left rear cross member locking unit SL 1 , the right rear cross member locking unit SL 2  is installed in the middle line of the dual cylinder placement supporting frame  60  and the right side frame locking unit SL 3  is installed at the right front of the dual cylinder placement supporting frame  60 , the next step is the installation of the dual cylinder placement supporting frame onto the vehicle frame  1  with details as follows: the dual gas cylinder placement supporting frame  60  mounting the gas cylinders  16  and  17  is inserted into the vehicle frame  1  and lifted it up as such there is enough room to enable the assembling of the left rear cross member locking unit SL 1  and right rear cross member locking unit SL 2  together. Subsequently, the left rear cross member locking unit SL 1  is assembled by hooking the left cross member locking bracket  72  with the rear cross member  14  on the left whereas the position of the through hole of the left rear cross member locking bracket  72  is aligned with that of the rear cross member  14  on the left. Then the left rear cross member locking sheet  73  is assembled inside the bottom of the rear member  14  on the left whereas the left rear cross member locking sheet  73  has a bolt through hole  19  which a bolt  19  is inserted through the left rear cross member locking sheet  73 , the rear cross member  14  and the left rear cross member locking bracket  72 , and fixed it, but loosely, with bolt  19  to the spot nut  18  fixed on the top of the left rear cross member locking bracket  72 . Other free locking bracket may be used, consistent with the spirit of the invention. Then the lower flange of the left sub-cross bracket  71  is assembled with the left bracket  64  (not shown) whereas the positions of the bolt through holes  19  of both parts are aligned. Subsequently, two bolts  19  are inserted through the holes of the left sub-cross bracket  71  and the left bracket  64 , then tightened it with spot nut  18  fixed on the inside of the left bracket  64  using a moderate tightening force. Next, it is the assembly of the right rear member locking unit SL 2  with the vehicle frame  1  and the dual gas cylinder placement supporting frame  60 : The cross member locking unit SL 2  on the right rear cross member locking bracket  77  is hooked with the rear cross member  14  on the right first, then the right rear cross member locking sheet  79  is assembled with the inside of the bottom of the rear cross member  14  on the right whereas the right rear cross member locking sheet  79  has a bolt through hole  19 . Subsequently, the bolt  19  is inserted through the right rear cross member locking sheet  79 , the rear cross member  14  and the right rear cross member locking bracket  77 , then tightened as in the same fashion as in the case of the left side, with the spot nut  18  fixed on the top of the right rear cross member locking bracket  77 . Other free locking bracket may be used, consistent with the spirit of the invention. Subsequently, the lower flange of the right sub cross bracket  76  is assembled with the right bracket  65  (not shown) as such the position of the bolt through hole  19  of both parts are aligned. Then, two bolts  19  are inserted through the holes of the right bracket  65  and the right sub-cross bracket  76  and tightened with the spot nuts  18  fixed on both right sub-cross brackets  76  with a moderate tightening force to complete the assembly of the dual gas cylinder placement supporting frame  60  in the middle line. Next, it is the assembly of the right side frame locking unit SL 3  with the dual gas cylinder placement supporting frame  60  and the vehicle frame  1 : the inner frame supporting bracket  85  of the right side frame locking unit SL 3  is assembled with the right frame member  11  whereas the position locking pintle  34 B is put into the side through hole of the right frame member  11  as to lock the position of the right side frame locking unit SL 3 , then the inner frame supporting bracket  85  is pushed to contact closely with the side of the right frame member  11 . Subsequently, the frame locking sleeve  46 B is assembled with concentrically with the through hole of the inner frame locking bracket  84  whereas this sleeve is blended over the top of the right frame member  11  and the rear bracket  48 B is assembled further whereas the sheet has a feature of a plate with two bolt through holes  19  and the outer rear supporting sheet  47 B featuring a assembled plate be means of fixing. Other free locking bracket may be used, consistent with the spirit of the invention. Then the bolt  19  is inserted through the hole of the rear bracket  48 B, the frame locking sleeve  46 B and the inner frame locking bracket  84 , and tightened with the spot nut  18  fixed inside the inner frame locking bracket  84 . Subsequently, the frame locking sleeve  46 B is assembled at the bottom of the right frame member  11  and fixed in the same fashion as with the other upper position. Then the lower flange of the inner frame supporting bracket leg  83  is assembled with the right bracket  65  whereas the positions of the through holes of both parts are aligned. Later, the bolts  19  are inserted through the holes of the inner frame supporting bracket leg  83  and the right bracket  65  and tightened with the spot nut s 18  fixed inside the right bracket  65 . 
     According to  FIG. 16 , the frame locking sheet on the rear line of the dual gas cylinder placement supporting frame  60  is fixed onto the vehicle frame  1 . Upon the complete installation of the left rear cross member locking unit SL 1 , the right rear cross member locking unit SL 2  and the right side frame locking unit SL 3 , the position of the through holes of the outer left frame locking sheet  67  and the outer right frame locking sheet  66  are well-aligned with the through holes on the left frame member  12  and the right frame member  11  enabling the parts to be assembled to one another whereas the inner left frame locking sheet  81  and the inner right frame locking sheet  82  each of which has a feature of a plate with two bolt through holes  19  and two spot nuts  18  fixed inside the left frame member  12  and the right frame member  11 . Subsequently, the bolts  19  are assembled by which the bolts are inserted through the outer left frame locking sheet  67 , the left frame member  12  and the inner left frame locking sheet  8 , then tightened with two spot nuts  18  fixed to the inner left frame  81  for locking the parts. Subsequently, the right frame is locking by which both of the inner right frame locking sheet  82  are assembled with the right frame member  11  inside and then two bolts  19  are assembled by inserting them through the outer right frame locking sheet  66 , the right frame member  11  and the inner right frame locking sheet  82  and tightened with two spot nuts  18  fixed inside the right frame locking sheet  82  for the assembly of the whole mounting device. At the end, the bolts  19  are tightened with the spot nuts  18  at all positions of the bolts with a locking unit that can measure the amount of the force.