Abstract:
A vehicle suspension assembly includes an axle member movable between a first position and a second position, mounting brackets adapted to couple to a vehicle frame assembly, trailing arms pivotably coupled to mounting brackets and pivotably coupled to the axle member, a lift arrangement including a pair of diaphragm chambers each having a push plate and a flexible bladder, the push plate of the diaphragm chamber dividing the associated diaphragm chamber into a first compartment and a second compartment, the first compartment of each diaphragm chamber being adjustably pressurized to move the push plate of the associated diaphragm chamber, and at least one push rod defining a single longitudinal axis and connected to each push plate such that pressurization of the diaphragm chambers cause a translational movement of the at least one push rod, thereby causing the axle member to move between the first and second positions.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to heavy duty vehicle suspensions and assemblies, and particularly to suspension assemblies incorporating a trailing arm-type configuration. More particularly, the present invention relates to an auxiliary vehicle suspension assembly adapted for movement between an in-use position and a storage position, and incorporating a self-steer assembly. 
     BRIEF SUMMARY OF THE INVENTION 
     One aspect of the present invention is to provide a vehicle suspension assembly comprising a first mounting bracket adapted to couple to a vehicle frame assembly, a first trailing arm having a first end pivotably coupled to the first mounting bracket, and a second end, wherein the second end of the trailing arm is located outboard of the first end of the trailing arm, a second mounting bracket adapted to couple to the vehicle frame assembly, and a second trailing arm having a first end pivotably coupled to the second mounting bracket, and a second end, wherein the second end of the trailing arm is located outboard of the first end of the second trailing arm. The vehicle suspension assembly further comprises an axle member having a first end and a second end, an integrated first mounting arrangement coupled to the first end of the axle member, wherein the first mounting arrangement pivotably couples the second end of the first trailing arm to the first end of the axle member, and wherein the first mounting arrangement couples the first end of the axle member to the first spindle assembly, and an integrated second mounting arrangement coupled to the first end of the axle member, wherein the second mounting arrangement pivotably couples the second end of the second arm to the second end of the axle member, and wherein the second mounting arrangement couples the second end of the axle member to the second spindle assembly. 
     Another aspect of the present invention is to provide a vehicle suspension assembly that comprises an axle member having a first end and a second end, a first mounting bracket adapted to couple to a vehicle frame assembly, a first trailing arm having a first end pivotably coupled the first mounting bracket, and a second end pivotably coupled to the axle member, a second mounting bracket adapted to couple to the vehicle frame assembly, and a second trailing arm having a first end pivotably coupled to the second mounting bracket, and a second end pivotably coupled to the axle member. The vehicle suspension assembly further comprises an integrated first mounting arrangement coupled to the first end of the axle member, wherein the first mounting arrangement couples the first end of the axle member to the first spindle assembly, and wherein the first mounting arrangement couples the first air spring to the first end of the axle member such that the first axle spring is adapted to extend between the first end of the axle member and the vehicle frame assembly, and an integrated second mounting arrangement coupled to the second end of the axle member, wherein the second mounting arrangement couples the second end of the axle member to the second spindle assembly, and wherein the second mounting arrangement couples a second air spring to the second end of the axle member such that the second air spring is adapted to extend between the second end of the axle member and the vehicle frame assembly. 
     Still another aspect of the present invention is to provide a vehicle suspension assembly that comprises an axle member having a first end and a second end, the axle member movable between a first position, wherein at least one tire coupled with the axle member contacts a ground surface, and a second position, wherein the at least one tire is spaced from the ground surface, a first mounting bracket adapted to couple to a vehicle frame assembly, a first trailing arm having a first end pivotably coupled to the first mounting bracket, and a second end pivotably coupled to the first end of the axle member, a second mounting bracket adapted to couple to a vehicle frame assembly, and a single trailing arm having a first end pivotably coupled to the second mounting bracket, and a second end pivotably coupled to the second end of the axle member. The vehicle suspension assembly further comprises a first lift arrangement comprising a first diaphragm chamber having a first push plate and a flexible bladder, the first push plate of the first diaphragm chamber dividing the first diaphragm chamber into a first compartment and a second compartment, the first compartment of the first diaphragm chamber being adjustably pressurized to move the first push plate of the first diaphragm chamber, a second diaphragm chamber having a second push plate including a flexible bladder, the second push plate of the second diaphragm chamber dividing the second diaphragm chamber into a first compartment and a second compartment, the first compartment of the second diaphragm chamber being adjustably pressurized to move the second push plate of the second diaphragm chamber, and at least one push rod defining a single longitudinal axis and connected to the first push plate and the second push plate such that pressurization of the first and second diaphragm chambers cause a translational movement of the at least one push rod, wherein the at least one push rod is operably coupled with the vehicle suspension assembly such that translational movement of the at least one push rod causes the axle chamber to move between the first and second positions. 
     Still yet another aspect of the present invention is to provide a method of assembling a vehicle suspension assembly comprising providing an axle assembly having a first end including a first mounting structure and a second mounting end, providing a first bearing block and a second bearing block, forming a first aperture in the first bearing block and a second aperture in the second bearing block, attaching the first and second bearing blocks to the first mounting structure subsequent to forming the first and second apertures, and providing a first spindle assembly coupled to the first mounting structure by a first spherical bearing located within the first aperture and a second spherical bearing located within the second aperture, wherein a first kingpin assembly extends through the first and second spherical bearings, thereby coupling the first spindle with the first mounting structure. 
     Another aspect of the present invention is to provide a vehicle suspension assembly comprising an axle assembly having a first end and a second end, a first mounting bracket and a second mounting bracket each adapted to couple to a vehicle frame assembly, and a first trailing arm having a first end operably coupled to the first mounting bracket and a second end pivotably coupled to the first end of the axle assembly. The vehicle suspension assembly further comprises a second mounting bracket adapted to couple to a vehicle frame assembly, and a second trailing arm having a first end pivotably coupled to the second mounting bracket, and a second end pivotably coupled to the second end of the axle assembly. The vehicle suspension assembly still further comprises a first air spring assembly coupled to a first end of the axle assembly such that the longitudinal axis of the first air spring assembly inclines inwardly from the first end of the axle assembly, and a second air spring assembly coupled to the second end of the axle assembly such that a longitudinal axis of the second air spring assembly inclines inwardly from the second end of the axle assembly, wherein a natural frequency of the suspension assembly is less than or equal to about 3 Hz. 
     The present inventive vehicle suspension assembly provides a durable, uncomplicated design that can be easily and quickly assembled, while simultaneously reducing manufacturing costs. The invention is efficient in use, economical to manufacture, capable of a long operating life, and is particularly well adapted to the proposed use. 
     These and other advantages of the present invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a vehicle suspension assembly embodying the present invention; 
         FIG. 2  is a perspective view of the vehicle suspension assembly with wheel and hub assemblies removed; 
         FIG. 3A  is a side elevational view of the vehicle suspension assembly in a lowered, in-use position; 
         FIG. 3B  is a side elevational view of the vehicle suspension assembly in a raised, storage position; 
         FIG. 4A  is a top plan view of the vehicle suspension assembly in an inline orientation; 
         FIG. 4B  is a top plan view of the vehicle suspension assembly in a turning orientation; 
         FIG. 5  is a side elevational view of the suspension assembly; 
         FIG. 6  is a top plan view of a trailing arm; 
         FIG. 7  is an exploded perspective view of a trailing arm assembly; 
         FIG. 8  is an exploded perspective view of mounting arrangement and associated connections; 
         FIG. 9A  is a perspective rear view of the mounting arrangement; 
         FIG. 9B  is a perspective front view of the mounting arrangement; 
         FIG. 10  is an exploded perspective view of a spindle assembly, wherein the components of the spindle assembly are shown in dashed in an exploded state and in solid in an assembled state; 
         FIG. 11  is an exploded perspective view of bearing blocks and a portion of the mounting arrangement, wherein the bearing blocks are shown in dashed in the exploded state and in solid in an assembled state; 
         FIG. 12A  is a cross-sectional view of the spindle assembly and a portion of the mounting arrangement; 
         FIG. 12B  is a cross-section view of the vehicle suspension assembly; 
         FIG. 13  is an exploded perspective view of an air spring assembly; 
         FIG. 14  is a rear elevational view of the suspension assembly; 
         FIG. 15A  is a perspective view of a lift arrangement; 
         FIG. 15B  is an exploded perspective view of the lift arrangement; and 
         FIG. 16  is a cross-section view of a dual diaphragm actuator, taken along the line XVI-XVI,  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     A suspension assembly  10  ( FIGS. 1 and 2 ) comprises a pair of mounting brackets  12  fixedly connected to a pair of longitudinally extending frame members  14  of a vehicle frame assembly and coupled to one another by a cross member  15 , a plurality of trailing arm assemblies including a pair of upper trailing arms  16  ( FIGS. 3A-4B ) and a pair of lower trailing arms  18 , an axle assembly  20 , and a pair of air spring assemblies  22  extending between the axle assembly  20  and corresponding frame members  14 . 
     In the illustrated example, each upper trailing arm  16  ( FIG. 5 ) includes a first end  24  pivotably coupled to one of the mounting brackets  12  for rotation about a pivot point  26  and a second end  28  pivotably coupled to the axle assembly  20  for rotation about a pivot point  30 , as described below. Each lower trailing arm  18  includes a first end  32  pivotably secured to a mounting bracket  12  for pivoting about a pivot point  34 , and a second end  36  pivotably coupled to the axle assembly  20  for pivotable movement around a pivot point  38 , also as described below.  FIGS. 4A and 6  illustrate the generally outward-sweeping shape of the trailing arms  16 ,  18  along the length of the trailing arms  16 ,  18  from the first end  24 ,  32  to the second end  28 ,  36 . As best illustrated in  FIG. 7 , each end  24 ,  28 ,  32 ,  36  of the trailing arms  16 ,  18  are pivotably secured to the mounting brackets  12  and axle assembly  20  by a bushing assembly  40  comprising a elastically resilient bushing member  42 , a bushing pin  44  and nylon washers  46  received within a corresponding bore  48 . 
     As best illustrated in  FIG. 8 , the second end  28 ,  36  of each trailing arm  16 ,  18  are pivotably coupled to an integrated corresponding mounting arrangement  50 . Each mounting arrangement  50  ( FIGS. 9A and 9B ) includes a triangularly-shaped rear plate  52 , an L-shaped front plate  54  that cooperates with the rear plate  52  to form an inwardly-opening pocket  56  within which an end  57  of an axle member  58  of the axle assembly  20  is received. The rear plate  52  and the front plate  54  each include a welding aperture  60  about which a weld is formed to secure the end  57  of the axle  58  within the pocket  56 . Each mounting arrangement  50  further includes a C-shaped spindle attachment plate  62  that is attached to the rear plate  52 , and which cooperates with the rear plate  52  and the front plate  54  to form a pocket  64  within which the second ends  28 ,  36  of the trailing arms  16 ,  18  are pivotably secured. As utilized herein, the term “integrated” means that the components of the mounting arrangement  50 , including the rear plate  52 , the front plate  54  and the spindle attachment plate  62  are brought together with one another such that the components form a single unit and are not spaced from one another. In the illustrated example, the rear plate  52 , the front plate  54  and the spindle attachment  62  are welded to one another, however these components may also be formed as a single integral piece, or coupled together with various mechanical fasteners. Spindle assemblies  66  (FIGS.  2  and  10 - 12 A) are pivotably secured to the corresponding mounting arrangement  50  of the axle assembly  20  by a pair of bearing assemblies  68  each including a bearing block  70  having a bearing bore  72  that receives a corresponding bearing  74 , each bearing  74  including a race  76  and a spherical bearing member  78 . The spindle attachment plate  62  includes a plurality of elongated welding apertures  80  about which a weld is received to weld the bearing blocks  70  to the spindle attachment plate  62  of the mounting arrangement  50 . It is noted that the bearing bore  72  of each of the bearing blocks  70  is machined prior to attaching the bearing block  70  to the mounting arrangement  50 . A kingpin assembly  82  including an elongated kingpin collar  84  and a kingpin  86  extends through the bearings  74  and an aperture  88  of the spindle  90 , thereby pivotably securing the spindle  90  to the axle assembly  20 . Specifically, tightening of the kingpin  86  creates a load path extending through the kingpin collar  84 , each of the spherical bearing members  78 , an end of the spindle  90 , and a collar member  92 . Over-tightening of the kingpin  86  is prevented by a washer member  94  positioned between the lower of the spherical bearing members  78  and the spindle  90 . It is noted that the lower of the bearing blocks  70  includes a collar portion  96  that abuts the race  76  of the corresponding bearing  74 , thereby providing proper spacing and assisting during assembly. Specifically, the collar portion or lip  96  provides a stop for the bearing to be pressed to during assembly, thereby defining the vertical positioning for the entire spindle assembly. Further, the lip  96  is adapted to support the vertical load should the press-fit of the bearing fail. A pair of retainer plates  98  are secured to the corresponding bearing blocks  70  by a plurality of bolts  100 . The hub assemblies  102 , breaking assemblies  103  and tires  104  are coupled to the associated spindle  90 . 
     Each mounting arrangement  50  ( FIGS. 9A and 9B ) includes forwardly and rearwardly extending air spring mounting brackets  108  to which the corresponding air spring assembly  22  ( FIG. 5 ) is coupled. In the illustrated example, the air spring mounting brackets  108  are integrated with the rest of the associated mounting arrangement, including the rear plate  52 , the front plate  54  and the spindle attachment bracket  62 . As best illustrated in  FIG. 13 , each air spring assembly  22  includes a rolling lobe-style air spring  110  including an air bladder  112 , an internal lobe member  114  and a top plate  116 . A mounting plate  118  is secured to the lobe member  114  via a plurality of mechanical fasteners  120 , with the mounting plate  118  being secured to the air spring mounting brackets  108  by a plurality of mechanical fasteners such as bolts  122 . The top plate  116  is secured to an upper mounting plate  124  by a plurality of mechanical fasteners  126 . The upper mounting plate  124  is attached to a corresponding vehicle frame rail  14 . As best illustrated in  FIG. 14 , the mounting arrangements  50  are located and configured such that the air spring assemblies  22  are inwardly inclined from the mounting assemblies  50  towards the vehicle frame rails  14  at an angle α, thereby resulting in a lower spring rate and reducing the interaction between the suspension and chassis and improving the control in a vehicle jounce event. Further, the incline of the spring assemblies  22  reduces the overall travel thereof, thereby allow use of rolling-lobe type air springs and reducing the overall cost. Preferably, angle α is between 30° and 45° from vertical, and more preferably between 30° and 35° from vertical, thereby resulting in a natural frequency for the vertical displacement or vibrations of the suspension assembly of less than or equal to about 3 Hz, and more preferably of between about 1 Hz and 2 Hz. 
     The outwardly-sweeping configuration of the trailing arms  16 ,  18  ( FIG. 12B ) in conjunction with the configuration and construction of the mounting arrangements  50 , provides for attachment of the trailing arms  16 ,  18 , the spindles  90 , and the air spring assemblies  22  in close proximity to one another and in close proximity to the ends of the axle member  20 . Preferably, the distance X between the center point of the connection of the trailing arms  16 ,  18  with the mounting arrangement  50  and the center point of the connection of the spindle  90  with the mounting arrangement  50  is less than or equal to about 6 inches, the distance Y between the center point of the connection between the spindle  90  with the mounting arrangement  50  and the center point of the connection between the air spring assembly  22  with the mounting arrangement  50  is less than or equal to about 14 inches, and the total length Z of the mounting arrangement  50  is less than or equal to about 20 inches. 
     As best illustrated in  FIGS. 3A and 3B , the vehicle suspension assembly  10  is vertically adjustable. Specifically, the axle assembly  20  is movable from a lowered position A, wherein the tires  104  contact a ground surface, thereby assisting and supporting the load of the vehicle, and a raised position B, wherein the tires  104  are spaced from the ground surface, thereby reducing tire wear and fuel consumption. The vehicle suspension assembly  10  includes a pair of lift arrangements  120  operably coupled with the associated upper trailing arms  16  and mounting brackets  12 . Each lift arrangement  120  includes a dual diaphragm chamber assembly  122  ( FIG. 15A-FIG .  16 ) including first diaphragm chamber  124  and a second diaphragm chamber  126 . Each diaphragm chamber  124 ,  126  includes a housing  128  divided into an upper chamber  130  and a lower chamber  132  by a deformable diaphragm  134  and a push plate  136 , wherein the upper chamber  130  may be pressurized via an air inlet  138 . Each push plate  136  is secured to a push rod  140  such that the push rods  140  are each forced in a direction  142  as the upper chamber  138  is pressurized. It is noted that in the illustrated example, the longitudinal axis  146  of each of the push rods  140  are aligned with one another. It is further noted that the dual push rods  140  may be replaced by a single push rod that extends through both the first diaphragm chamber  124  and the second diaphragm chamber  126 . The diaphragm chamber assembly  122  is attached to a corresponding upper trailing arm  16  by a lift bracket  148 , while the push rod  140  associated with the second diaphragm chamber  126  is pivotably coupled to an associated mounting bracket  12  by a push rod plate  150  that is fixedly coupled to the mounting bracket  12 , and a clevis arrangement  152  that is attached to the end of the push rod  140  of the second diaphragm chamber  126  and pivotably coupled to the push rod plate  150 . It is noted that the configuration of the diaphragm chamber assembly  122  results in a beveling of the force exerted on the associated push rods  150  while maintaining a reduced overall plan area required to house or position the diaphragm chamber assembly  122  within the overall vehicle suspension assembly  10 . 
     The vehicle suspension assembly  10  further comprises a self-steer assembly which pivots the spindles  90  and the tires  104  between an inline orientation C, as illustrated in  FIG. 4A , and a turning orientation B, as illustrated in  FIG. 4B . In the illustrated example, the steering assembly  160  includes a tie rod  162  pivotably coupled to spindle arms  164  ( FIG. 14 ) associated with each spindle  90 . The steering assembly  160  further includes a pair of damper assemblies  166  pivotably secured to the spindle arms  164  and the axle  58  via a pair of mounting brackets  170  ( FIG. 2 ). 
     In the foregoing description it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts as disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their express language state otherwise.