Abstract:
Disclosed herein is a novel chassis design that is functionally identical to the chassis represented in the U.S. patent application Ser. Nos. 14/059,062, 14/087,552, and 14/246,108. Based on a ladder-type structure representative of one ordinarily designed for a utility vehicle or truck, the novel chassis includes a frame that is constructed with a low slung middle section and high arched front and rear sections. This way, the powertrain is located in the middle section at the same level as are the suspension control link frame mounting points. In contrast, the powertrain in the chassis represented by the cited applications is located above the suspension control link frame mounting points. Since the powertrain directly impacts the center of gravity and since the suspension control link frame mounting points are located at the lowest level of the frame in both the present invention and cited applications, then the present invention improves upon the handling characteristics of the chassis associated with the cited applications by lowering the center of gravity while preserving ground clearance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application represents a novel chassis whose frame is specifically designed to operate in conjunction with the suspension system, drivetrain, and steering system covered in U.S. patent application Ser. Nos. 14/059,062, 14/087,552, and 14/246,108, respectively. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
       [0003]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    Disclosed in patent application Ser. No. 14/059,062 is a type of double A-arm suspension configuration derived from Ford&#39;s twin I-beam front suspension system. This suspension system cooperates with the drivetrain disclosed in patent application Ser. No. 14/087,552 and the steering system disclosed in patent application Ser. No. 14/246,108. These three cooperative functions are installed on a frame, and thereby represent a chassis for a four wheel drive (4WD) vehicle. The frame possesses a ladder-type structure that lies in a single horizontal plane whereby the powertrain is positioned between the frame sides while the frame mounting points for the suspension control links are positioned below the frame sides. 
         [0005]    In general, a vehicle&#39;s handling characteristics improve as the center of gravity height is decreased. Given that a significant portion of a vehicle&#39;s weight is due to the powertrain which in turn affects the center of gravity, then a vehicle&#39;s handling characteristics can be improved by decreasing the resting height of the powertrain. Predictably therefore, the handling of a vehicle constructed with the chassis represented by the cited applications can be improved by decreasing the resting height of the powertrain. Resting height refers to the distance that the powertrain resides above the ground. 
         [0006]    Decreasing the resting height of the powertrain can be easily achieved by lowering the vehicle closer to the ground; e.g., by reducing the length or spring rate of the suspension springs, a technique widely adopted by sports cars. However such a technique also acts to decrease the ground clearance of the vehicle, an act contrary to the predominant characteristic of any off-road vehicle such as a 4WD vehicle. 
         [0007]    Since the chassis represented by the cited applications is directed towards a 4WD vehicle, then a 4WD vehicle constructed with this chassis would acquire improved handling without compromising off-road capability if the resting height of the powertrain was decreased without sacrificing ground clearance. Accordingly, the present invention addresses this issue by offering a chassis design whose powertrain sits lower in the frame without sacrificing ground clearance than does the powertrain in the chassis represented in the cited applications. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The present invention addresses a chassis design derived from the chassis associated with the suspension system, drivetrain, and steering system covered in U.S. patent application Ser. Nos. 14/059,062, 14/087,552, and 14/246,108, respectively. 
         [0009]    The present invention also addresses a chassis design that: 
         [0000]    utilizes a suspension link configuration functionally identical to the one disclosed in U.S. patent application Ser. No. 14/059,062, whereby both the spring and damping processes are furnished by the segmented air shock absorber, this shock absorber being covered in U.S. patent application Ser. No. 13/854,055;
 
utilizes a drivetrain functionally identical to the one disclosed in U.S. patent application Ser. No. 14/087,552, except that an offset power coupler is also connected to the rear differential housing;
 
utilizes a steering system functionally identical to the one disclosed in U.S. patent application Ser. No. 14/246,108, except that the bellcrank is discarded;
 
employs a ladder-type frame constructed with a unique low slung middle section and high arched front and rear sections whereby the powertrain resides at the same level as the middle section, reverse power couplers are incorporated into the frame sides of the front and rear sections, and front and rear differential housings are located in the front and rear sections above the reverse power couplers, respectively, the ladder-type structure of the frame being common in the art and representative of one ordinarily built for utility vehicles and trucks;
 
improves upon the handling characteristics of the chassis associated with the cited applications by lowering the center of gravity while preserving off-road capability; a quality achieved by effectively lowering the powertrain in the frame without changing ground clearance, the lowering effect resulting from the present invention using a frame that locates the powertrain at the same level as the frame mounting brackets for the suspension links compared to the cited applications using a frame that locates the powertrain above the frame mounting brackets for the suspension links.
 
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     List of Reference Numerals Utilized in the Drawings 
       [0000]    
       
           10 —front cross beam 
           11 —rear cross beam 
           12 —transmission cross-member 
           13 —transfer case cross-member 
           14 —driver frame side front part 
           15 —driver frame side middle part 
           16 —driver frame side rear part 
           17 —driver frame side angled part 
           18 —passenger frame side front part 
           19 —passenger frame side middle part 
           20 —passenger frame side rear part 
           21 —passenger frame side angled part 
           22 —driver reverse power coupler 
           23 —passenger reverse power coupler 
           24 —driver upper leading link frame mounting bracket 
           25 —driver lower leading link frame mounting bracket 
           26 —passenger upper leading link frame mounting bracket 
           27 —passenger lower leading link frame mounting bracket 
           28 —driver upper trailing link frame mounting bracket 
           29 —driver lower trailing link frame mounting bracket 
           30 —passenger upper trailing link frame mounting bracket 
           31 —passenger lower trailing link frame mounting bracket 
           32 —driver upper leading link 
           33 —driver lower leading link 
           34 —passenger upper leading link 
           35 —passenger lower leading link 
           36 —driver upper trailing link 
           37 —driver lower trailing link 
           38 —passenger upper trailing link 
           39 —passenger lower trailing link 
           40 —steering box 
           41 —pitman arm 
           42 —swingset arm 
           43 —connector link 
           44 —front driver tie rod 
           45 —front passenger tie rod 
           46 —rear driver tie rod 
           47 —rear passenger tie rod 
           48 —driver steering knuckle 
           49 —passenger steering knuckle 
           50 —driver non-steering knuckle 
           51 —passenger non-steering knuckle 
           52 —segmented air shock absorber 
           53 —engine 
           54 —transmission 
           55 —transfer case 
           56 —front differential housing 
           57 —rear differential housing 
           58 —front offset power coupler 
           59 —rear offset power coupler 
           60 —front drive shaft 
           61 —rear drive shaft 
           62 —driver short axle shaft 
           63 —passenger short axle shaft 
           64 —driver long axle shaft 
           65 —passenger long axle shaft 
           66 —engine mounting bracket 
           67 —driver differential housing mounting bracket 
           68 —passenger differential housing mounting bracket 
       
     
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0069]      FIG. 1  is a side perspective view of the frame with suspension control link frame mounting brackets for a 4WD vehicle; 
           [0070]      FIG. 2  is a side perspective view of the frame with suspension and steering systems for a 4WD vehicle, 
           [0071]      FIG. 3  a top plan view thereof; 
           [0072]      FIG. 4  is a side perspective view of the chassis for a 4WD vehicle; 
           [0073]      FIG. 5  a top plan view thereof; 
           [0074]      FIG. 6  is a front view of the front end of the chassis at ride height thereof; 
           [0075]      FIG. 7  is a front view of the front end of the chassis articulated thereof. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0076]    The chassis disclosed in this application refers to a frame that interactively operates with the suspension system, drivetrain, and steering system covered in U.S. patent application Ser. Nos. 14/059,062, 14/087,552, and 14/246,108, respectively. The suspension system refers to a hybrid comprised of elements from Ford&#39;s twin I-beam front suspension system and a double A-arm suspension system, and utilizes the segmented air shock absorber for both the spring and damping processes, this shock absorber being covered in U.S. patent application Ser. No. 13/854,055. The drivetrain includes a powertrain, reverse power couplers, front and rear differential housings, and offset power couplers. The steering system is based on a swingset design and includes a steering box, swingset arm, connector link, and tie rods. 
         [0077]    Regarding the drawings, a chassis/frame for a 4WD vehicle is illustrated in detail. In a given drawing, certain parts are either not shown due to graphical limitations of the view or are not labeled in order to emphasize other parts.  FIG. 6  shows the front of the chassis whereby the cross beam of the frame is selectively transparent in order to reveal the steering box on the driver side and parts of the drivetrain on the passenger side. 
         [0078]    Referring to  FIG. 1 , the frame with the mounting brackets for the suspension control links is illustrated. The structure of the frame is based on a ladder-type design commonly used with utility vehicles and trucks. The driver and passenger frame sides lay side-by-side, each side being aligned with and equally spaced from the longitudinal line, the longitudinal line passing through the center of the vehicle from front to back. The driver and passenger frame sides are connected to one another at the front and rear ends by the front and rear cross-beams  10  and  11  and in the middle by the transmission and transfer case cross-members  12  and  13 , respectively. 
         [0079]    The driver and passenger frame sides each consist of five parts—a front part  14  and  18 , middle part  15  and  19 , rear part  16  and  20 , and one and the other angled parts  17  and  21 , respectively—the parts of the combined driver and passenger frame sides referring to the front, middle, rear, and one and the other angled sections of the frame. The front and rear sections occupy one horizontal plane while the middle section occupies a second horizontal plane whereby the plane occupied by the front and rear sections is above that occupied by the middle section. The front and rear sections are located at the front and rear ends of the frame while the middle section is located in the middle of the frame and refers to the section of the frame that is closest to the ground. One and the other angled sections serve to connect the front and rear sections to the middle section, respectively. The one angled section projects downward and outward from the front section to the middle section while the other angled section projects downward only from the rear section to the middle section. This way, the parts of the driver and passenger frame sides in the front section are closer to the longitudinal line than are those in the rear and middle sections, the front section being narrower to enable a smaller turning radius. 
         [0080]    Referring to  FIG. 1 , the frame with the mounting brackets for the suspension control links is illustrated, and to  FIGS. 2 and 3 , the frame with the suspension and steering systems is illustrated, emphasizing in this case particularly the configuration of the suspension system. While the suspension configuration in the present invention is the same as that disclosed in patent application Ser. No. 14/059,062, the locations of the suspension control link mounting brackets on the frames are different: 
         [0081]    The front driver or passenger upper and lower leading links  32  and  33  or  34  and  35  extend laterally from the front passenger or driver reverse power coupler  23  or  22  to the front driver or passenger knuckle  48  or  49 , the front passenger or driver reverse power coupler  23  or  22  being proximate the front passenger or driver wheel (not shown), respectively; while the rear driver or passenger upper and lower leading links  32  and  33  or  34  and  35  extend laterally from the rear passenger or driver reverse power coupler  23  or  22  to the rear driver or passenger knuckle  50  or  51 , the rear passenger or driver reverse power coupler  23  or  22  being proximate the rear passenger or driver wheel (not shown), respectively. 
         [0082]    The first ends of the front or rear driver and passenger upper leading links  32  and  34  are affixed to flexible joints, the flexible joints are pivotally attached to mounting brackets  24  and  26 , and the mounting brackets  24  and  26  are affixed to the middle of the front or rear passenger and driver reverse power couplers  23  and  22  above the output shafts; while, the first ends of the front or rear driver and passenger lower leading links  33  and  35  are affixed to flexible joints, the flexible joints are pivotally attached to mounting brackets  25  and  27 , and the mounting brackets  25  and  27  are affixed to the bottoms of the front or rear passenger and driver reverse power couplers  23  and  22  below the output shafts, respectively. Also each shaft and mounting bracket  24 ,  25 ,  26 , or  27  project inward towards the longitudinal line. The driver or passenger reverse power coupler  22  or  23  is incorporated into both the driver or passenger frame side front and rear parts  14  and  16  or  18  and  20 , thereby the front and rear sections of the frame each include the driver and passenger reverse power couplers  22  and  23 , respectively. The incorporation is implemented in a manner such that the middle and bottom of the driver or passenger reverse power coupler  22  or  23  are located substantially at the same levels as the top and bottom of the middle section thereby locating the mounting brackets  24  and  25  or  26  and  27  substantially at the same levels as the top and bottom of the middle section, respectively. The result is that the mounting brackets  24  and  25  or  26  and  27  are effectively located at the same level as the middle section (mounting brackets  24  and  25  are shown in  FIG. 6 ). A level refers to a horizontal plane, the plane being parallel to the longitudinal line. 
         [0083]    The front driver or passenger upper and lower trailing links  36  and  37  or  38  and  39  extend outwardly from the transmission cross-member  12  to the front driver or passenger knuckle  48  or  49  while the rear driver or passenger upper and lower trailing links  36  and  37  or  38  and  39  extend outwardly from the transfer case cross-member  13  to the rear driver or passenger knuckle  50  or  51 , respectively. 
         [0084]    The first ends of the front driver or passenger upper and lower trailing links  36  and  37  or  38  and  39  are affixed to flexible joints, the flexible joints are pivotally attached to mounting brackets  28  and  29  or  30  and  31 , and the mounting brackets  28  and  29  or  30  and  31  are vertically affixed above and on the transmission cross-member  12 , respectively. The first ends of the rear driver or passenger upper and lower trailing links  36  and  37  or  38  and  39  are affixed to flexible joints, the flexible joints are pivotally attached to mounting brackets  28  and  29  or  30  and  31 , and the mounting brackets  28  and  29  or  30  and  31  are vertically affixed above and on the transfer case cross-member  13 , respectively. Also each mounting bracket  28 ,  29 ,  30 , or  31  projects outward away from the longitudinal line. The mounting brackets  28  and  29  or  30  and  31  are attached to (1) the transmission cross-member  12  in a manner such that the mounting brackets  28  and  29  or  30  and  31  are located substantially at the same levels as the top and bottom of the middle section or (2) the transfer case cross-member  13  in a manner such that the mounting brackets  28  and  29  or  30  and  31  are located substantially at the same levels as the top and bottom of the middle section. The result is that the mounting brackets  28  and  29  or  30  and  31  are effectively located at the same level as the middle section. A level refers to a horizontal plane, the plane being parallel to the longitudinal line. 
         [0085]    The second ends of the driver or passenger upper leading and trailing links  32  and  36  or  34  and  38  are attached to the upper apex bracket while the second ends of the driver or passenger lower leading and trailing links  33  and  37  or  35  and  39  are attached to the lower apex bracket, respectively. The upper and lower apex brackets each contain a ball joint, and the ball joints are pivotally attached either to the top and bottom of the driver or passenger steering knuckle  48  or  49  or to the top and bottom of the driver or passenger non-steering knuckle  50  or  51 , respectively. 
         [0086]    Note: having the front and rear sections positioned above the middle section permits the use of longer reverse power couplers  22  and  23  without changing ground clearance compared to that in the cited application, thereby effectively increasing the vertical distance between the frame sides and mounting bracket  24 ,  25 ,  26 , or  27  without changing ground clearance. This feature allows the suspension to have the same compression travel as that in the cited application without the need for apertures in the frame sides. 
         [0087]    Referring to  FIGS. 4 and 5 , the chassis is illustrated and to  FIGS. 6 and 7 , the front of the chassis is illustrated, emphasizing in this case particularly the drivetrain. While the drivetrain described herein operates in the same manner as that disclosed in patent application Ser. No. 14/087,552, the configuration of and components used in each drivetrain are different: 
         [0088]    The engine  53 , transmission  54 , and transfer case  55  are located in the front, middle, and middle sections all at the same level as the middle section, being secured to the frame with the engine mounting brackets  66 , and transmission and transfer case cross-members  12  and  13 , respectively. Meanwhile, the front and rear differential housings  56  and  57  are located in the front and rear sections at the same level as the front and rear sections, each being secured to the frame with driver and passenger differential housing mounting brackets  67  and  68 , respectively. Since the middle section is positioned below the front and rear sections, then the engine  53 , transmission  54 , and transfer case  55  are positioned below the front and rear differential housings  56  and  57  resulting in a misalignment between the first and second output shafts of the transfer case  55  and the pinion shafts of the front and rear differential housings  56  and  57 , respectively. Front and rear offset power couplers  58  and  59  are used to restore this alignment: first, the front or rear offset power coupler  58  or  59  is directly connected to the front or rear differential housing  56  or  57  such that the output shaft of the front or rear offset power coupler  58  or  59  is adapted to the pinion shaft of the front or rear differential housing  56  or  57 , respectively; and second, the front offset power coupler  58  is projected downward and towards the driver side of the engine  53  such that the input shaft of the front offset power coupler  58  is aligned with the first output shaft of the transfer case  55  while the rear offset power coupler  59  is projected straight downward such that the input shaft of the rear offset power coupler  59  is aligned with the second output shaft of the transfer case  55 , the rear offset power coupler  59  being absent in the cited application. The alignments refer (1) to the input shaft of the front offset power coupler  58  occupying the same line occupied by the first output shaft of the transfer case  55 , the line being positioned between the engine  53  and driver frame side, the line being parallel to the longitudinal line and (2) to the input shaft of the rear offset power coupler  59  occupying the same line occupied by the second output shaft of the transfer case  55 , the line being the longitudinal line. The alignments minimize the angles adopted by the flexible joints on the front and rear drive shafts  60  and  61 , thereby ensuring that power is transmitted smoothly, efficiently, and free of vibration from the transfer case  55  to the front and rear offset power couplers  58  and  59 , respectively. 
         [0089]    Power is transmitted from the engine  11  to the transmission  12  then from the transmission  12  to the transfer case  13  in a manner typical in the art. The front drive shaft  60  has a front and rear ends, each end is affixed to a flexible joint whereby the flexible joint on the front end is attached to the input shaft of the front offset power coupler  58  and that on the rear end is attached to the first output shaft of the transfer case  55 ; the attachments enable power to be transmitted from the transfer case  55  to the front offset power coupler  58 . Likewise, the rear drive shaft  61  has a front and rear ends, each end is affixed to a flexible joint whereby the flexible joint on the front end is attached to the second output shaft of the transfer case  55  and that on the rear end is attached to the input shaft of the rear offset power coupler  59 ; the attachments enable power to be transmitted from the transfer case  55  to the rear offset power coupler  59 . 
         [0090]    Power is able to be transmitted from the front and rear offset power couplers  58  and  59  to the front and rear differential housings  56  and  57  due to the output shafts of the front and rear offset power couplers  58  and  59  being adapted to the pinion shafts of the front and rear differential housings  56  and  57 , respectively. 
         [0091]    The first ends of the front driver and passenger short axle shafts  62  and  63  are pivotally attached to the flexible joint flanges on the driver and passenger sides of the front differential housing  56  and the second ends of the front driver and passenger short axle shafts  62  and  63  are pivotally attached to the input shafts of the front driver and passenger reverse power couplers  22  and  23  thereby enabling power to be transmitted from the front differential housing  56  to the front driver and passenger reverse power couplers  22  and  23 ; while the first ends of the front driver and passenger long axle shafts  64  and  65  are pivotally attached to the output shafts of the front passenger and driver reverse power couplers  23  and  22  and the second ends of the front driver and passenger long axle shafts  64  and  65  are pivotally attached to the front driver and passenger wheel hubs (not shown) thereby enabling power to be transmitted from the front passenger and driver reverse power couplers  23  and  22  to the front driver and passenger wheel hubs, respectively. The front driver or passenger wheel hub has a first and second sides such that the first side is rotatably attached to the driver or passenger steering knuckle  48  and  49  and the second side is attached to the front driver or passenger wheel, respectively. 
         [0092]    The first ends of the rear driver and passenger short axle shafts  62  and  63  are pivotally attached to the flexible joint flanges on the driver and passenger sides of the rear differential housing  57  and the second ends of the rear driver and passenger short axle shafts  62  and  63  are pivotally attached to the input shafts of the rear driver and passenger reverse power couplers  22  and  23  thereby enabling power to be transmitted from the rear differential housing  57  to the rear driver and passenger reverse power couplers  22  and  23 ; while the first ends of the rear driver and passenger long axle shafts  64  and  65  are pivotally attached to the output shafts of the rear passenger and driver reverse power couplers  23  and  22  and the second ends of the front driver and passenger long axle shafts  64  and  65  are pivotally attached to the rear driver and passenger wheel hubs (not shown) thereby enabling power to be transmitted from the rear passenger and driver reverse power couplers  23  and  22  to the rear driver and passenger wheel hubs, respectively. The rear driver or passenger wheel hub has a first and second sides such that the first side is rotatably attached to the driver or passenger non-steering knuckle  50  and  51  and the second side is attached to the rear driver or passenger wheel, respectively. 
         [0093]    Referring to  FIGS. 2 and 3 , the frame with the suspension and steering systems is illustrated and to  FIGS. 6 and 7 , the front of the chassis is illustrated, emphasizing in this case particularly the configuration of the steering system. While the steering system described herein operates in the same manner as that disclosed in patent application Ser. No. 14/246,108, the components used in each steering system are different: 
         [0094]    A steering box  40  with a long output shaft is attached to the inner part of the front driver frame side such that the output shaft projects downward towards the ground and lies alongside the front driver reverse power coupler  22  thereby locating the pitman arm  41  immediately above the front passenger upper leading link frame mounting bracket  26 . This way the pitman arm  41  can be pivotally attached directly to the front passenger tie rod  45  and connector link  43 , thereby obviating the need for a bellcrank and simplifying the configuration of the steering system. In the cited application, a draglink pivotally attaches the pitman arm  41  to the horizontal arm of the bellcrank while the vertical arm of the bellcrank is pivotally attached to the front passenger tie rod  45  and connector link  43 . 
         [0095]    Steering input originates at the steering wheel (not shown) and passes through the firewall (not shown) to the steering shaft via a steering column (not shown) in a manner common in the art. The steering shaft is pivotally attached to the input shaft of the steering box  40 , thereby transmitting steering input from the steering shaft to the steering box  40 . The output shaft of the steering box  40  is attached to the pitman arm  41 . The pitman arm  41  is pivotally attached to the first ends of the front passenger tie rod  45  and connector link  43  while the second ends of the front passenger tie rod  45  and connector link  43  are pivotally attached to the passenger steering knuckle  49  and swingset arm  42 , thereby enabling steering input to be transmitted directly from the steering box  40  to the passenger steering knuckle  49  and swingset arm  42 , respectively. The swingset arm  42  is pivotally attached to the first end of the front driver tie rod  44  while the second end of the front driver tie rod  44  is pivotally attached to the driver steering knuckle  48 , thereby enabling steering input to be transmitted from the swingset arm  42  to the driver steering knuckle  48 . 
         [0096]    The first ends of the rear driver and passenger tie rods  46  and  47  are pivotally attached to mounting brackets while the mounting brackets are attached to the rear passenger and driver reverse power couplers  23  and  22  above the rear driver and passenger upper leading link frame mounting brackets  24  and  26 , respectively; the second ends of the rear driver and passenger tie rods  46  and  47  are pivotally attached to the driver and passenger non-steering knuckles  50  and  51 , respectively. The rear driver and passenger tie rods  46  and  47  travel up and down in concert with the rear driver and passenger upper and lower leading links  32  and  33 , and  34  and  35  without any lateral movement, the lack of lateral movement preventing the driver and passenger non-steering knuckles  50  and  51 , respectively, from turning thereby locking them into a straight-ahead orientation. 
         [0097]    While the invention has been illustrated and described as embodied in a vehicle chassis, it is not intended to be limited to the details shown, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the scope and spirit of the present invention.