Patent Publication Number: US-2009236167-A1

Title: Support frame for auxiliary power unit for a motor vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related to U.S. Utility patent application Ser. No. 11/386,964 filed on Mar. 22, 2006 and entitled “Auxiliary Power Unit For A Vehicle” and whose teachings are incorporated into this document by reference thereto. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates, in general, to auxiliary power units and, more particularly, this invention relates to a support frame for an auxiliary power unit employed on vehicles, such as long-haul trucks and, yet more particularly, the instant invention relates to a support frame for an auxiliary power unit employed on motor vehicles that isolates the auxiliary power unit from the effects of road shock and vibration. 
     BACKGROUND OF THE INVENTION 
     As is generally well known, Auxiliary Power Unit (APU) is employed extensively on motor vehicles such as long-haul trucks to provide electrical power and enable control of the climate environment in the cab when the truck is parked and its engine has been shut-off. It is also well known that APU requires frequent maintenance and servicing and must withstand continuous effects of road shock and vibration experienced during operation of the truck. 
     Prior to the conception and design of the present invention efforts have been made to improve access to APU during maintenance and servicing and to isolate the APU from effects of road shock and vibration. U.S. Pub. No. 2007/0221431 to Hirsch, the inventor of the present invention, discloses an auxiliary power system for a vehicle that has a frame with two longitudinal beams. The APU is mounted on a support frame that is pivotably mounted to the vehicle frame to permit pivoting in a vertical plane. The support frame further includes a suspension system at an intermediate location between the pivot mount and the APU to help isolate the APU from the effects of road vibration. The APU itself is mounted on rollers so that the APU can be slid out of its housing and be supported by open housing door for access and/or removal. While such system has alleviated difficulties associated with presently employed APUs, it has been found that the support frame encroaches on vehicle&#39;s components mounted within the vehicle frame. It has been further found that arrangement enabling sliding movement of the APU increases manufacturing costs. 
     Therefore, there is a continuing need for an improved support frame to mount APU to the vehicle frame that provides ease of access to APU during maintenance, decreases manufacturing costs and isolates APU from undesirable effects of road shock and vibration. 
     SUMMARY OF THE INVENTION 
     According to one aspect, the invention provides an auxiliary power system for a motor vehicle. The auxiliary power system includes a first frame. An auxiliary power unit is mounted on the first frame. A second frame is provided and is mounted in a stationary position to a predetermined portion of such motor vehicle. There is means which is coupled to the first and second frames for enabling movement of the first frame in a vertical plane relative to the second frame to isolate the auxiliary power unit from the effects of road shock and vibration. 
     According to another aspect of the invention there is provided, in combination with an auxiliary power unit for a vehicle, a frame assembly for isolating the auxiliary power unit from the effects of road shock and vibration. The frame assembly includes a first frame. The first frame has a pair of vertically disposed side members, each having a predetermined shape and inwardly and horizontally disposed bottom flange. A first cross member is secured at each end thereof to a respective top end of each side member. A second cross member is secured at each end thereof to a respective side member intermediate ends thereof. A base plate is provided and the auxiliary powered unit is affixed thereto. Elastomeric isolation mounts are employed for attaching the base plate to the flanges of the side members. The frame assembly also includes a second frame. The second frame has a pair of side members each having a first vertically disposed portion thereof positioned coplanar in abutting engagement with the longitudinal rail of the vehicle and a second vertically disposed portion extending outwardly from and generally perpendicular to the first portion. A pair of are apertures formed through the first vertical portion and are spaced in a vertical direction for enabling attachment of the second frame to the side rail with fasteners. A cross member is rigidly secured at each end thereof to a respective side member of the second frame intermediate ends thereof. The frame assembly additionally includes a pair of spring elements each operable in a vertical direction and having a first end thereof pivotally connected to a respective side member of the first frame and having a second end thereof pivotally connected to a respective side member of the second frame. The spring elements enable the first frame to move in a vertical plane relative to the second frame for isolating the auxiliary power unit from the effects of road shock and vibration. Finally, the support frame includes a pair of elastomeric isolation mounts operably secured to the cross member of the second frame for abuttingly engaging the second cross member of the first frame and for terminating a downward movement of the first frame after termination of the effects of road shock and vibration. 
     According to yet another embodiment, the invention provides an auxiliary power system for a vehicle. The auxiliary power system includes an auxiliary power unit and a suspension means mounted to a single longitudinal rail of the vehicle frame and securely receiving the auxiliary power unit, whereby the auxiliary power unit is allowed to move in a vertical plane relative to the longitudinal rail of the vehicle for withstanding the effects of road shock and vibration. 
     OBJECTS OF THE INVENTION 
     It is, therefore, one of the primary objects of the present invention to provide a support frame for APU employed on motor vehicles, such as long-haul trucks. 
     Another object of the present invention is to provide an APU support frame that provides ease of access to APU for maintenance and replacement. 
     Yet another object of the present invention is to provide an APU support frame that isolates the APU from undesirable effects of road shock and vibration. 
     A further object of the present invention is to provide an APU support frame that enables movement of the APU in a vertical plane. 
     Yet a further object of the present invention is to provide an APU support frame that compensates for noise and vibration generated by APU during its operation. 
     An additional object of the present invention is to provide an APU support frame that is cost effective to manufacture. 
     Another object of the present invention is to provide an APU support frame that is simple to install. 
     In addition to the several objects and advantages of the present invention which have been described with some degree of specificity above, various other objects and advantages of the invention will become more readily apparent to those persons who are skilled in the relevant art, particularly, when such description is taken in conjunction with the attached drawing Figures and with the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a long-hole truck with an auxiliary power unit system of the present invention; 
         FIG. 2  is a front isometric view of the auxiliary power unit system of the present invention; and 
         FIG. 3  is a front isometric view of the support frame employed within the auxiliary power unit system and constructed in accordance with a presently preferred embodiment of the invention. 
     
    
    
     BRIEF DESCRIPTION OF THE VARIOUS EMBODIMENTS OF THE INVENTION 
     Prior to proceeding to the more detailed description of the present invention, it should be noted that, for the sake of clarity and understanding, identical components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawing figures. 
     The best mode for carrying out the invention is presented in terms of its presently preferred embodiment, herein depicted within  FIGS. 1 through 3 . However, the invention is not limited to the described embodiment, and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     Reference is now made to  FIG. 1  that depicts an environment wherein the support frame assembly, generally designated as  20 , of the present invention is employed. Particularly shown is a long-haul truck  2 . The truck  2  includes a cab  4  to which a sleeper cabin  6  may be connected. The truck  2  also includes a truck frame  8  that supports the cab  4  and sleeper cabin  6 , as well as a fuel tank  12 . The truck frame  8  is generally formed by a pair of longitudinally disposed rails  10 , only one of which is shown in  FIGS. 1-3 . The auxiliary power unit (APU) system  14  of the present invention is configured to be supported by only one existing rail  10 , preferably between the fuel tank  12  and the wheels  16 . 
     The support frame assembly  20 , constructed in accordance with a presently preferred embodiment of the invention, is best shown in  FIGS. 2-3 . The support frame assembly  20  includes a first frame, generally designated as  30 , on which is the APU system  14  is mounted. Specifically, the first frame  30  includes a first vertically disposed plate-like side member  32  having an inwardly and horizontally disposed flange  33  and a second vertically disposed plate-like side member  34  having an inwardly and horizontally disposed flange  35 . Preferably, the vertically disposed portions of the side members  32  and  34  have identical shape except for the orientation of the flanges  33  and  35 . The APU system  14  is then operably supported on such flanges  33  and  35 . A first cross member  36 , preferably having an L-cross-section is secured at each end thereof to a respective top end of the side member  32 ,  34 . The manner in which the APU system  14  is secured to the flanges  33  and  35  depends on the construction of the specific APU system  14 . Exemplary APU system  14  of  FIG. 2  requires a plurality of mounting brackets  40  having a horizontally disposed first portion  42  secured, with fasteners (not shown) to a respective flange  33 ,  35  and having a vertically disposed second portion  44  secured, with fasteners (not shown) to a bottom end of the APU system  14 . It will be understood that APU system  14  of a different construction will require different securing arrangement either directly to the flanges  33 ,  35  or through the use of mounting brackets. The final essential element of the first frame  30  is a second cross member  46  secured at each end thereof to a respective side member  32 ,  34  intermediate ends thereof. 
     There is also provided a second frame, generally designated as  60 , which is mounted in a stationary position on the truck  2 . The second side frame  60  includes a vertically disposed first side member  62  and a vertically disposed second side member  64 . Each side member  62 ,  64  has a first plate-like portion  66  thereof positioned in abutting engagement with an exterior surface of the longitudinal rail  10  of the truck frame  8 . A pair of apertures  68  are formed through such first portion  66  in order to secure the side member  62 ,  64  to the longitudinal rail  10  with the use of fasteners (not shown). A second plate-like portion  70  of each side member  62 ,  64  extends outwardly from and generally perpendicular to first portion  66 . The side members  62  and  64  are generally identical except for orientation of the first portion  66 . Although the first portion  66  of each side members  62  and  64  has been illustrated in  FIGS. 2-3  as inwardly formed, it is also within the scope of the present invention to outwardly form such first portion  66 , as shown by reference character  66 ′ in  FIG. 3 . A cross member  72  is rigidly secured at each end thereof to a respective side member  62 ,  64  intermediate ends thereof. 
     The present invention also provides means coupled to the first and second frames,  30  and  60  respectively, for isolating the APU system  14  from the effects of road shock and vibration, whereby the first frame  30  is allowed to pivot and move, both in a vertical plane, relative to the second frame  60  and further relative to the truck frame  8 . In order to provide for such vertically pivotal movement, the isolating means includes a pair of spring elements  80 . Each spring element  80  is operable in a vertical direction and has a first end  82  thereof pivotally connected to the side member  32 ,  34  of the first frame  30  at a first pivot  84 . The spring element  80  also has a second end  86  thereof pivotally connected to a respective side member  62 ,  64  of the second frame  60  at a second pivot  88 . The spring element  80  may be a conventional shock absorber, as shown in  FIGS. 2-3  or an elastomeric air spring which is not shown but which is well known in the art. The first and second pivots  84  and  88  are preferably identical and being formed by a pin  90  rigidly secured to the respective side member  32 ,  34 ,  62  or  64  and cooperating with a simple aperture  92  formed through each of the first and second ends,  82  and  86  respectively, of the spring element  80 . However, it is within the scope of the present invention to form the aperture  92  through the respective side member  32 ,  34 ,  62  or  64  and adapt the first and second ends,  82  and  86  respectively, with the pin  90 . It is also within the scope of the present invention to employ other well known pivot arrangements. 
     In use, the APU system  14  is secured to the flanges  33 ,  35  of the first frame  30 . The first frame  30  is then secured to the longitudinal rail  10  of the truck frame  8 . During operation, the shocks experienced by the truck  2  from road surface impurities are transferred to the support frame  20  through the truck frame  8 . Upon receiving such effects of road shock and vibration, the first frame  30  pivotally moves in a vertical plane relative to the second frame  60  and to the truck frame  8  since the spring elements  80  are positioned toward the top of the frame assembly  20 . Depending on whether the truck has encountered a cavity or a bump in a road surface, the bottom right-hand corner of the first frame  30 , as viewed in  FIGS. 2-3 , will move away or toward the truck frame  8 . When the effect of the road shock subside, the first frame  30  will pivotally return to its normal position and such movement will be cushioned or dampened by the spring elements  80 . 
     The presently preferred material of the first and second frames,  30  and  60  respectively, is metal and, more particularly, such as steel. The presently preferred method of securing various components of each frame therebetween is by a welding process, although use of fasteners is also contemplated. 
     It will be appreciated that the APU system  14  is essentially suspended, by way of the support frame  20 , from the exterior surface of a single longitudinal rail  10  and is allowed to move in a vertical plane relative to the longitudinal rail  10  for withstanding effects of road shock and vibration. 
     The shape of the side members  32 ,  34  of the first frame  30  is predetermined based on the shape and size of the APU system  14  to maximize position of such APU system  14  external to the longitudinal rail  10  of the truck frame  8  but within the required space envelop, provide required clearance in a vertical direction from the road surface and minimize encroachment of the support frame  20  internal of the longitudinal rail  10 . 
     To further cushion or dampen the pivotal movement of the first frame  30  and to prevent stopping such downward movement by way of spring elements  80 , the present invention contemplates a stop means, for example, such as a pair of stop members  96 , only one of which is shown in  FIG. 3 . The stop members  96  are preferably attached to the cross member  72  of the second frame  60  and abut the bottom surface of the second cross member  46  of the first frame  30  for controlling pivotal movement of the first frame  30 . Preferably, such stop members  96  are manufactured from an elastomeric material, such as hard rubber. It is further presently preferred to employ a well known elastomeric isolation mounts of the type as manufactured by Corry Rubber Corporation of Cory, Pa. Advantageously, such elastomeric isolation mounts further provide shock and vibration attenuation between the first frame  30  and the second frame  60 . 
     It will be understood that the spring elements  80  and the isolating mounts  96  are selected to withstand the frequency generated due to effects of road shock and vibration and prevent the support frame  20  and the APU system  14  from resonating at such frequency. 
     It is also within the scope of the present invention to isolate the support frame  20  from the noise and vibration generated by operating APU system  14 . Accordingly, the present invention provides a base plate  100  which has the APU system  14  secured thereon by way of mounting brackets  40  and a plurality of elastomeric isolation mounts  102  disposed essentially between the base plate  100  and the flanges  33 ,  35  of the first frame  30 . It would be appreciated that the elastomeric isolation mounts  102  may be identical to the elastomeric isolation mounts used as stop members  96 . 
     Although the present invention has been shown in terms of the second frame  60  being disposed within the first frame  30  wherein a portion of the each side member  32 ,  34  of the first frame  30  is disposed coplanar with the second vertically disposed portion  70  of the second frame  60 , it will be apparent to those skilled in the art, that the side members  62 ,  64  of the second frame  60  may be positioned external to the respective side members  32 ,  34  of the first frame  30 . 
     Furthermore, various cover members may be provided for enclosing the APU system  14  within the support frame  20 . For the sake of clarity a bottom cover  110  and a front cover  114  are shown in  FIG. 1 , while only the bottom cover member  110  is shown in  FIGS. 2-3 . The covers  110 ,  114  may be simply attached by way of fasteners (not shown) and apertures  112  formed in the side members  32 ,  34  of the first frame  30 . 
     It will be also appreciated that the support frame  30  is adapted with air communication means such as a pipes  120  and  122  for proper operation of the APU system  14 . 
     Also, the spring elements  80  may be provided as hydraulic or pneumatic cylinders. 
     Furthermore, the present invention contemplates that the isolating mounts  96  may be replaced with a second pair of spring elements  80  also operable in a vertical direction. When four spring elements  80  are employed, the first frame  30  will move generally linear in a vertical plane, particularly, when one end of each spring element has a non-pivotal connection to a respective frame member. 
     Thus, the present invention has been described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same. It will be understood that variations, modifications, equivalents and substitutions for components of the specifically described embodiments of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.