Abstract:
Disclosed herein is a novel steering system specifically designed to operate in conjunction with the powered version of the extreme-travel independent suspension system that is disclosed in the U.S. patent application Ser. No. 14/087,552. Based on a steering mechanism commonly found in off-road racing trucks built around Ford&#39;s twin I-beam front suspension system, this novel steering system comprises a type of swingset steering linkage structure. Unique features of this novel steering system include a right-angle bellcrank and swingset arm whereby the vertical bellcrank arm functions like the swingset arm. This novel steering system utilizes front or rear driver and passenger tie rods operating in coincidence with their counterpart suspension links to control the directional orientation of the steering or non-steering knuckles with minimal bump steer or change in toe throughout suspension travel, respectively.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application represents a novel steering system specifically designed to operate in conjunction with the powered version of the extreme-travel independent suspension system. The powered version of this suspension system is covered in U.S. patent application Ser. No. 14/087,552. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     Disclosed in patent application Ser. No. 14/087,552 is a powered version of a novel independent suspension system. The novel suspension system is a type of double A-arm suspension system derived from Ford&#39;s twin I-beam front suspension system, this novel suspension system being covered in patent application Ser. No. 14/059,062. While the powered version introduces a unique means of transmitting power from a powertrain to the wheels, the suspension system lacks a means of controlling the directional orientation of the knuckles, the knuckles being rotatably attached to the wheels. 
     Given that many types of production-based vehicles are routinely used in industries that involve off-road driving, e.g., construction, farming and ranching, mining, forestry, gas and oil exploration, where many obstacles—e.g., boulders, fallen trees, ravines, cliffs—exceed the limits of suspension travel, then automobile manufacturers and numerous other industries would greatly benefit from a powered version of this novel long travel suspension system that possessed the ability to control the directional orientation of both the steering and non-steering knuckles, particularly for a four wheel drive (4WD) vehicle. 
     Controlling the directional orientation of the knuckles in a production-based vehicle equipped with front and rear independent suspension systems typically involves tie rods: in the case of the steerable (usually front) knuckles, the tie rods operate with other parts of a steering system; whereas in the case of the non-steerable (usually rear) knuckles, the tie rods operate with one of their ends being attached to a rigid body such as the frame, cross-member, or bracket assembly. Also, most 4WD vehicles equipped with a double A-arm front suspension system employ a steering system that utilizes a tie rod to transmit steering input from the frame to the steering knuckle. Bump steer is minimized by aligning the ends of the tie rods with the ends of the A-arms. The same technique holds for a double A-arm rear suspension system. Functionally, the ends of the tie rods comply with the same coincidence principle as do the ends of the axle shafts. So long as the ends of the tie rods are coincident with the ends of the A-arms throughout suspension travel, then the tie rods will move in concert with the A-arms and the steerable (front) knuckles can be turned with minimal bump steer while the non-steerable (rear) knuckles can be locked into a straight-ahead direction with minimal change in toe throughout suspension travel. 
     Off-road vehicles equipped with Ford&#39;s twin I-beam front suspension system employ a type of swingset steering system. Typical swingset steering systems include a steering box, swingset lever arms, draglinks, and tie rods, the number of each component used depending on the application. As a type of idler arm, the swingset lever arm hangs vertically downward such that the top end is pivotally attached to the frame or cross-member while the bottom end can swing laterally parallel to a line passing through the front wheels, the top end being attached to the frame or cross-member in the same position as is the frame end of one of the I-beams. The steering box is attached to the driver frame side in the same position as the frame end of say the second I-beam. In applications involving one swingset lever arm, the swingset lever arm is attached to the passenger frame side in the same position as is the frame end of say the one I-beam. The steering box transmits steering input to the swingset lever arm via a draglink and to the passenger knuckle via the second tie rod while the swingset lever arm transmits steering input to the driver knuckle via the one tie rod. In applications involving two swingset lever arms, one and the second swingset lever arms are located at the driver and passenger sides of the vehicle in the same positions as are the frame ends of one and the second I-beams, respectively. The steering box transmits steering input to one swingset lever arm via one draglink. The one swingset lever arm transmits steering input to the second swingset lever arm via a second draglink and to the passenger knuckle via the one tie rod while the second swingset lever arm transmits steering input to the driver knuckle via the second tie rod. 
     In principle a type of swingset steering system is suitable for the present invention so long as it&#39;s compatible with the suspension system covered in patent application Ser. No. 14/059,062. In particular, a swingset lever arm linkage arrangement operating in conjunction with a front tie rod arrangement that is coincident with the front upper and lower leading links can transmit steering input from a steering box to the steering knuckles with minimal bumpsteer throughout suspension travel. Meanwhile, a rear tie rod arrangement that is coincident with the rear upper and lower leading links can lock the non-steering knuckles into a straight-ahead orientation with minimal change in toe throughout suspension travel. Thusly, the present invention offers a steering system design based on a swingset lever arm linkage arrangement that cooperates with tie rods as a means of contrail the direction orientation of both the steering and non-steering knuckles in the powered version of the novel independent suspension system disclosed in patent application Ser. No. 14/087,552. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention represents a novel steering system design whose components include a Saginaw recirculating ball-type steering box, bellcrank, swingset arm, draglink, connector link, and tie rods. This design is based on a type of swingset lever arm linkage arrangement commonly found in off-road racing trucks. In particular, this design uses the same type of tie rod to control the directional orientation of both steering and non-steering knuckles. The steering and non-steering knuckles are associated with the independent suspension systems installed at both the front and rear ends of a vehicle, respectively. 
     The present invention also represents a steering system that: 
     is specifically designed to operate in conjunction with the powered version of the novel independent suspension system disclosed in U.S. patent application Ser. No. 14/087,552; 
     involves a steering circuit whereby steering input is transmitted from the firewall to the steering box via a steering shaft, then to the bellcrank via a draglink, then to the swingset arm via a connector link, and then the bellcrank and swingset arm transmit steering input to the front passenger and driver steering knuckles via tie rods, respectively;
 
employs a right-angle bellcrank comprised of two arms called horizontal and vertical arms. Originating at the driver frame side, the horizontal arm projects horizontally across to the passenger frame side while the vertical arm projects vertically downward to the ground. The vertical arm comprises the same features (i.e., size, dimensions, attachment points) as does the swingset arm;
 
employs one tie rod per wheel, whereby (1) the front driver or passenger tie rod is positioned at the front passenger or driver reverse power coupler in a manner such that the frame end of the front driver or passenger tie rod is coincident with the first ends of the front driver or passenger up er and lower leading links and the wheel end of the front driver passenger tie rod is coincident with ball joints; the ball joints serve to pivotally connect the second ends of the front driver or passenger upper and lower leading links to the top and bottom of the driver or passenger steering knuckle; the cooperative effect of these coincident alignments enables the front driver or passenger tie rod to control the directional orientation of the driver or passenger steering knuckle with minimal bump steer throughout suspension travel, receptively; and (2) the rear driver or passenger tie rod is positioned at the rear passenger or driver reverse power coupler in a manner such that the frame end of the rear driver or passenger tie rod is coincident with the first ends of the rear driver or passenger upper and lower leading links and the wheel end of the rear driver or passenger tie rod is coincident with ball joints; the ball joints serve pivotally connect the second ends of the rear driver or passenger upper and lower leading links to the top and bottom of the driver or passenger non-steering knuckle; the cooperative effect of these coincident alignments enables the rear driver or passenger tie rod to control the straight-ahead orientation of the driver or passenger non-steering knuckle with minimal change in toe throughout suspension travel, respectively;
 
controls the directional orientation of steering knuckles with a swinging motion whereby the frame ends of the front driver and passenger tie rods are pivotally connected to the bottoms the swingset and vertical bellcrank arms; the tops of the swig et and vertical bellcrank arms are pivotally connected to the front passenger and driver reverse power couplers with mounting brackets in a manner such that the bottoms of the swingset and vertical bellcrank arms are able to swing laterally thereby transmitting steering input to the front driver and passenger tie rods, which then is transmitted to the driver and passenger steering knuckles thereby making them turn, respectively;
 
controls the straight-ahead orientation of non-steering knuckles with a rigid attachment whereby the frame ends of the rear driver and passenger tie rods are pivotally connected to the rear passenger and driver reverse power couplers with mounting brackets; the rigid attachments of the mounting brackets to the rear passenger and driver reverse power couplers prevent any lateral motion by the rear driver and passenger tie rods thereby acting to lock the driver and passenger non-steering knuckles into a straight-ahead orientation, respectively.
 
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     List of Reference Numerals Utilized in the Drawings 
     
         
           10 —frame 
           11 —engine 
           12 —transmission 
           13 —transfer case 
           14 —steering box 
           15 —steering shaft 
           16 —pitman arm 
           17 —bellcrank 
           18 —swingset arm 
           19 —draglink 
           20 —connector link 
           21 —front driver tie rod 
           22 —front passenger tie rod 
           23 —rear driver tie rod 
           24 —rear passenger tie rod 
           25 —front differential housing 
           26 —rear differential housing 
           27 —offset power coupler 
           28 —front drive shaft 
           29 —rear drive shaft 
           30 —driver short axle shaft 
           31 —passenger short axle shaft 
           32 —driver long axle shaft 
           33 —passenger long axle shaft 
           34 —driver upper leading link 
           35 —driver lower leading link 
           36 —passenger upper leading link 
           37 —passenger lower leading link 
           38 —driver upper trailing link 
           39 —driver lower trailing link 
           40 —passenger upper trailing link 
           41 —passenger lower trailing link 
           42 —driver steering knuckle 
           43 —passenger steering knuckle 
           44 —driver non-steering knuckle 
           45 —passenger non-steering knuckle 
           46 —driver differential housing mounting bracket 
           47 —passenger differential housing mounting bracket 
       
    
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a close-up side perspective view of the front driver frame side steering components for a 4WD vehicle; 
         FIG. 2  is a close-up side perspective view of the front passenger frame side steering components thereof; 
         FIG. 3  is a side perspective view of the front and rear steering and suspension systems for a 4WD vehicle; 
         FIG. 4  a top plan view thereof; 
         FIG. 5  is a side perspective view of the chassis for a 4WD vehicle; 
         FIG. 6  a top plan view thereof; 
         FIG. 7  is a front view of the front end of the chassis at ride height thereof; 
         FIG. 8  is a front view of the front end of the chassis articulated thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention represents a steering system designed to function with the powered version of the independent suspension system disclosed in U.S. patent application Ser. No. 14/087,552. The suspension system is based on Ford&#39;s twin I-beam front suspension system that incorporates a type of double A-arm configuration per wheel. The drivetrain includes a unique gearbox known as a reverse power coupler. Incorporated into the frame side, the reverse power coupler comprises external components including the input and output shafts and mounting brackets for the leading links in the suspension system. 
     Regarding the drawings, a steering system for a four-wheel drive vehicle is illustrated in detail and installed within a frame  10  in conjunction with a suspension system and drivetrain. Components of the steering system include a steering box  14 , bellcrank  17 , swingset arm  18  steering shaft  15 , draglink  19 , connector link  20 , and front and rear driver and passenger tie rods  21  and  22 , and  23  and  24 , respectively. The steering system is arranged among the drivetrain components that include the front and rear differential housings  25  and  26 , offset power coupler  27 , and front and rear driver and passenger reverse power couplers, respectively. The drivetrain refers to the powertrain which includes an engine  11 , transmission  12 , and transfer case  13 . The front or rear driver and passenger tie rods  21  and  22  or  23  and  24  are configured to interactively operate with the front or rear suspension system, each suspension system includes driver and passenger upper and lower leading links  34  and  35 , and  36  and  37  and driver and passenger upper and lower trailing links  38  and  39 , and  40  and  41 , respectively. 
     Referring to  FIGS. 3-6 , the frame  10  with front and rear independent suspension systems and drivetrain for a 4WD vehicle is illustrated emphasizing in this case particularly the properties of the front and rear driver and passenger tie rods  21  and  22 , and  23  and  24 , respectively. These properties: 
     Involve the bellcrank  17  whereby bellcrank  17  consists of horizontal and vertical arms and has a right-angle shape such that the horizontal arm projects outward away from the inner frame side and towards the engine bay while the vertical arm hangs downward towards the ground. The horizontal and vertical arms are connected to each other at the apex such that the apex serves as the top of the vertical arm, the top of the vertical arm is pivotally connected to the driver reverse power coupler. 
     Involve the type of steering arm that is connected to the front or rear driver or passenger tie rod  21 ,  22 ,  23 , or  24 , respectively. The steering arm is located at the top portion of the driver or passenger steering or non-steering knuckle  42 ,  43 ,  44 , or  45  in a manner commonly seen in a high steer kit whereby the steering arm is an integral part of the driver or passenger steering or non-steering knuckle  42 ,  43 ,  44 , or  45 , respectively. High steer kits are typically installed on a kingpin type of steering knuckle. By design the end of the steering arm projects outward away from the driver or passenger steering knuckle  42  or  43  and towards the front end of the vehicle and slightly inward towards the front differential housing  25 , and from the driver or passenger non-steering knuckle  44  or  45  and towards the rear end of the vehicle and slightly inward towards the rear differential housing  26 , respectively. 
     Are based on one tie rod per wheel, whereby: (1) the front driver and passenger tie rods  21  and  22  are pivotally connected to the bottoms of the swingset arm  18  and vertical bellcrank arm, respectively. A mounting bracket pivotally connects the top of the swingset arm  18  to the front passenger reverse power coupler, the location of the mounting bracket on the front passenger reverse power coupler serves to position the bottom of the swingset arm  18  in a manner such that the frame end of the front driver tie rod  21  is aligned with the first ends of the front driver upper and lower leading links  34  and  35  and the wheel end of the front driver tie rod  21  is aligned with ball joints, the ball joints serving to pivotally connect the second ends of the front driver upper and lower leading links  34  and  35  to the top and bottom of the driver steering knuckle  42 , respectively. Likewise a mounting bracket pivotally connects the top of the vertical bellcrank arm to the front driver reverse power coupler the location of the mounting bracket on the front driver reverse serves to position the bottom of the vertical bellcrank arm in a manner such that the frame end of the front passenger tie rod  22  is aligned with the first ends of the front as and lower leading links  36  and  37  and the wheel end of the front passenger tie rod  22  is aligned with ball joints, the ball joints serving to pivotally connect the second ends of the front passenger upper and lower leading links  36  and  37  to the top and bottom of the passenger steering knuckle  43 , respectively; (2) a mounting bracket pivotally connects the rear driver tie rod  23  to the rear passenger reverse power coupler, the location of the mounting bracket on the rear passenger reverse power coupler serves to align the frame end of the rear driver tie rod  23  with the first ends of the rear driver upper and lower leading links  34  and  35  and to align the wheel end of the rear driver tie rod  23  with ball joints, the ball joints serving to pivotally connect the second ends of the rear driver upper and lower leading links  34  and  35  to the top and bottom of the driver non-steering knuckle  44 , respectively. Likewise a mounting bracket pivotally connects the rear passenger tie rod  24  to the rear driver reverse power coupler, the location of the mounting bracket on the rear driver reverse power coupler serves to align the frame end of the rear passenger tie rod  24  with the first ends of the rear passenger upper and lower leading links  36  and  37  and to align the wheel end of the rear passenger tie rod  24  with ball joints, the ball joints serving to pivotally connect the second ends of the rear passenger upper and lower leading links  36  and  37  to the top and bottom of the passenger non-steering knuckle  45 , respectively; and (3) this alignment (a) refers to the frame end of the front driver or passenger tie rod  21  or  22  lying on a vertical line that passes through the first ends of the front driver or passenger upper and lower leading links  34  and  35  or  36  and  37  and to the wheel end of the front driver or passenger tie rod  21  or  22  occupying a vertical plane that is occupied by the ball joints, respectively; (b) refers to the frame end of the rear driver or passenger tie rod  23  or  24  lying on a vertical line that passes through the first ends of the rear driver or passenger upper lower leading links  34  and  35  or  36  and  37  and to the wheel end of the rear driver or passenger tie rod  23  or  24  occupying a vertical plane that is occupied by the ball joints respectively; wherein each vertical plane is parallel to the longitudinal axis, the longitudinal axis referring to a line passing through the center of the vehicle from front to back; and (c) enables the front driver or passenger tie rod  21  or  22  to be coincident with the front driver or passenger upper and lower leading links  34  and  35  or  36  and  37  such that bumpsteer is minimized throughout suspension travel, respectively; and, enables the rear driver or passenger tie rod  23  or  24  to be coincident with the rear driver or passenger upper and lower leading links  34  and  35  or  36  and  37  such that a change in toe is minimized throughout suspension travel, respectively. 
     Referring to  FIGS. 1 ,  2 ,  7 , &amp;  8 , there are close up illustrations of the front end of a 4WD vehicle with a front independent suspension system emphasizing in this case particularly the steering system interacting with the front independent suspension system. Affixed to the inner frame side above the bellcrank  17  is the steering box  14  whereby the input shaft of the steering box  14  is pivotally attached to the second end of the steering shaft  15  with a U-joint. This way, the U-joint attachment enables steering input to be transmitted from the steering shaft  15  to the steering box  14 , whereby steering input originates at the steering wheel (not shown) and passes through the firewall (not shown) to the steering shaft  15  via a steering column (not shown) in a manner common in the art. The output shaft of the steering box is a sector shaft, the sector shaft projects outward away from the inner frame side and towards the engine bay, whereby the sector shaft is attached to a pitman arm  16 . Positioned downward from the steering box  14  to the bellcrank  17  is the draglink  19 . The draglink  19  has a top and bottom ends, whereby the top end is pivotally connected to the pitman arm  16  and the bottom end is pivotally connected to the horizontal bellcrank arm, thereby enabling the transmission of steering input from the steering box  14  to the bellcrank  17 . The mounting bracket that pivotally connects the to of the vertical bellcrank arm to the front driver reverse power coupler positions the bellcrank  17  next to the front driver frame side aperture between the aperture and middle of the driver frame side in a manner such that the bottom of the vertical bellcrank arm can swing laterally within a vertical plane that parallels a line passing through the front wheels; whereas, the mounting bracket that pivotally connects the top of the swingset arm  18  to the front passenger reverse power couple positions the swingset arm  18  next to the front passenger frame side aperture between the aperture and front end of the passenger frame side in a manner such that the bottom of the swingset arm  18  can swing laterally within a vertical plane that parallels a line passing through the front wheels. This lateral swinging motion creates the lateral force that transmits steering input from the bellcrank  17  and swingset arm  18  to the passenger and driver tie rods  22  and  21 , respectively. 
     The first and second ends of the connector link  20  are pivotally connected to the bottoms of the vertical bellcrank arm and swingset arm  18  thereby enabling the transmission of steering input from the bellcrank  17  to the swingset arm  18 , respectively. The bottoms of the vertical bellcrank arm and swingset arm  18  are also pivotally connected to the frame ends of the front passenger and driver tie rods  22  and  21  thereby enabling the transmission of steering input from the bellcrank  17  and swingset arm  18  to the front passenger and driver tie rods  22  and  21 , respectively. The wheel ends of the front driver and passenger tie rods  21  and  22  are pivotally connected to the steering arms of the driver and passenger steering knuckles  42  and  43  thereby enabling the transmission of steering input from the front driver and passenger tie rods  21  and  22  to the driver and passenger steering knuckles  42  and  43  which then causes the driver and passenger steering knuckles  42  and  43 , respectively, to turn. 
     Referring to  FIGS. 3-6 , the frame  10  with front and rear independent suspension systems and drivetrain for a 4WD vehicle is illustrated emphasizing in this case particularly components of the steering system interacting with the rear independent suspension system. The mounting bracket that pivotally connects the frame end of the rear driver tie rod to the rear passenger reverse power coupler is positioned next to the rear passenger frame side aperture between the aperture and rear end of the passenger frame side while the mounting bracket that pivotally connects the frame end of the rear passenger tie rod to the rear driver reverse power coupler is positioned next to the rear driver frame side aperture between the aperture and middle of the driver frame side. The wheel ends of the rear driver and passenger tie rods  23  and  24  are pivotally connected to the steering arms of the driver and passenger non-steering knuckles  44  and  45 . Since the frame end of the rear driver or passenger tie rod  23  or  24  is only able to pivot within its mounting bracket, the rear driver or passenger tie rod  23  or  24  travels up and down in concert with the rear driver or passenger upper and lower leading links  34  and  35  or  36  and  37 , respectively, without any lateral movement. The lack of lateral movement by the rear driver or passenger tie rod  23  or  24  prevents the driver or passenger non-steering knuckle  44  or  45 , respectively, from turning thereby locking it into a straight-ahead orientation. 
     While the invention has been illustrated and described as embodied in a vehicle steering system, 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.