Abstract:
An air spring assembly for a vehicle includes a spring seat adapted to be secured to vehicle structure of the vehicle. The spring seat has a post extending therefrom. The air spring assembly includes an inflatable air spring having a mounting cap for attachment to the spring seat. The mounting cap has a cavity extending therein to receive the post. The air spring assembly further includes a retaining member extending through the mounting cap and over the post to prevent the post from exiting the cavity to attach the mounting cap to the spring seat.

Description:
TECHNICAL FIELD 
     The present invention relates generally to air springs for vehicles and, more particularly, to an air spring assembly for a vehicle. 
     BACKGROUND OF THE INVENTION 
     It is known to provide an air spring assembly for a vehicle between a chassis frame or body rail (on a unibody vehicle) and axle or lower control arm thereof. Typically, the air spring assembly includes an inflatable air spring diaphragm with a lower end fastened to the axle and an upper end fastened to the frame of the vehicle. Generally, fasteners such as bolts, clips, split pins, rivets, or nuts are used to fasten the air spring assembly to the axle and the frame. However, for some applications, there is not enough hand and tool clearance to tighten the fasteners. 
     As a result, it is desirable to provide an air spring assembly for a vehicle that is easy to install. It is also desirable to provide an air spring assembly for a vehicle that eliminates the need for separate fasteners. It is further desirable to provide an air spring assembly for a vehicle that has a low cost and simple mounting feature. Therefore, there is a need in the art to provide an air spring assembly for a vehicle that meets at least one of these desires. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is an air spring assembly for a vehicle. The air spring assembly includes a spring seat adapted to be secured to vehicle structure of a vehicle. The spring seat has a post extending therefrom. The air spring assembly includes an inflatable air spring having a mounting cap for attachment to the spring seat. The mounting cap has a cavity extending therein to receive the post. The air spring assembly further includes a retaining member extending through the mounting cap and over the post to prevent the post from exiting the cavity to attach the mounting cap to the spring seat. 
     One advantage of the present invention is that an air spring assembly is provided for a vehicle having a low cost, simple mounting feature. Another advantage of the present invention is that the air spring assembly requires no special tool for assembly and service. Still another advantage of the present invention is that the air spring assembly has a self-aligning feature guiding the air spring to the spring seat. A further advantage of the present invention is that the air spring assembly allows a jounce bumper for a coil spring to be mounted to a washer which holds a U-pin and air spring. Still a further advantage of the present invention is that the air spring assembly has a positive holding to prevent the air spring from falling off the spring seat when the air spring is empty. Another advantage of the present invention is that the air spring assembly allows the air spring to have an internal jounce bumper which enables the air suspension to share suspension architecture with a coil spring suspension. Yet another advantage of the present invention is that the air spring assembly requires no threaded fasteners. Still another advantage of the present invention is that the air spring assembly has a self-retention feature that holds the U-pin in place. 
     Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an air spring assembly, according to the present invention, illustrated in operational relationship with a vehicle. 
         FIG. 2  is a sectional view taken along line  2 - 2  of  FIG. 1 . 
         FIG. 3  is a perspective view of a portion of the air spring assembly of  FIG. 1 . 
         FIG. 4  is a partial elevational view of a portion of the air spring assembly of  FIG. 1 . 
         FIG. 5  is a sectional view taken along line  5 - 5  of  FIG. 2 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings and in particular  FIG. 1 , one embodiment of an air spring assembly  10 , according to the present invention, is shown for a vehicle (partly shown), such as a pick-up truck, sport utility vehicle, or car, generally indicated at  12 . Such vehicles  12  typically include a frame  14  (partially shown) and an axle  16 . It should be appreciated that the air spring assembly  10  is mounted between the axle  16  and frame  14  to support a vehicle body (not shown). It should also be appreciated that the air spring assembly  10  may be mounted between the frame  14  and a lower control arm (not shown) of the vehicle. 
     In the embodiment illustrated, the air spring assembly  10  includes a lower spring seat  18  disposed on the axle  16 . The lower spring seat  18  is generally circular in shape. The lower spring seat  18  includes at least one flange  20  extending downwardly thereto. The lower spring seat  18  is secured to the axle  16  by a suitable mechanism such as welding or fasteners (not shown) or be formed as part of the axle  16 . It should be appreciated that, in another embodiment, the lower spring seat  18  is secured to the lower control arm (not shown) by a suitable mechanism such as welding or fasteners (not shown) or be formed as part of the lower control arm. 
     The air spring assembly  10  includes an air spring, generally indicated at  21 , disposed between the lower spring seat  18  and an upper spring seat  52  to be described. The air spring  21  includes an inflatable air spring diaphragm  22  extending vertically. The air spring diaphragm  22  is generally cylindrical in shape and has a generally circular shaped cross-section. The air spring  21  also includes a lower mounting cap  24  at a lower end of the diaphragm  22  and attached to the lower spring seat  18  by a suitable mechanism (not shown). The lower mounting cap  24  is generally circular in shape and the diaphragm  22  rolls on the lower mounting cap  24 . It should be appreciated that the lower mounting cap  24  could be contoured to meet air spring rates for a comfort ride. It should also be appreciated that the lower mounting cap  24  may have a feature (not shown) to be attached to the lower spring seat  18  to be removably attached thereto. 
     The air spring  21  further includes an upper mounting cap  26  at an upper end of the diaphragm  22 . The upper mounting cap  26  has a base wall  28  that mates with an upper spring seat  52  to be described. The base wall  28  includes a channel  30  formed therein extending radially across and axially inward. The base wall  28  includes a cavity  32  extending therein. The cavity  32  is generally circular in cross-sectional shape and is located approximately in the center of the base wall  28 . It should be appreciated that the channel  30  communicates with the cavity  32 . 
     The upper mounting cap  26  also has a side wall  34  located inwardly from the edge of the base wall  28 . The side wall  34  is annular and extends generally perpendicular to the base wall  28 . The side wall  34  has at least one, preferably a plurality of, such as two, apertures  36  spaced circumferentially and extending radially therethrough for a function to be described. 
     The upper mounting cap  26  has at least one, preferably a plurality of, such as two, channel members  38  extending from the side wall  34  and along the base wall  28 . The channel members  38  are aligned with the apertures  36  in the side wall  34 . The channel members  38  are arcuately shaped in cross-section and extend radially along the inside of the base wall  28  to the cavity  32  and extend radially beyond the cavity  32  for a function to be described. The channel members  38  are orientated generally perpendicular to the channel  30 . It should be appreciated that the channel members  38  have passages (not shown) extending therein with openings  40  to communicate with the cavity  32 . 
     The upper mounting cap  26  further has a tab  42  extending radially from the base wall  28 . The tab  42  is generally rectangular in shape and is located in a recess  43  in the periphery of the base wall  28 . The tab  42  is disposed above and circumferentially between the apertures  36  in the side wall  34 . The tab  42  has at least one, preferably a plurality of, such as two, projections  44  extending generally perpendicularly therefrom. The projections  44  are generally hemi-spherical in shape for a function to be described. 
     The upper mounting cap  26  is made of a rigid material such as metal or plastic. The upper mounting cap  26  is a monolithic structure being integral, unitary, and one-piece. 
     The air spring assembly  10  includes a retaining member  46  to retain the upper mounting cap  26  to an upper spring seat  52  to be described. The retaining member  46  is generally “U” shaped and is a non-threaded U-pin. The retaining member  46  has a base portion  48  extending laterally and a pair of opposed side portions  50  extending generally perpendicularly from the ends of the base portion  48  to form a general “U” shape. The base portion  48  and side portions  50  have a generally circular cross-sectional shape. The retaining member  46  is made of a rigid material such as metal. The retaining member  46  is a monolithic structure being integral, unitary, and one-piece. 
     The air spring assembly  10  further includes an upper spring seat  52  connected to the frame  14 . The upper spring seat  52  has a top wall  54  that is generally planar and mates with the upper mounting cap  26 . The top wall  54  has at least one, preferably a plurality of, such as two, projections or keys  56  spaced radially and extending toward the air spring  21  for a function to be described. The upper spring seat  52  has a post  58  extending generally perpendicularly to the top wall  54 . The post  58  is generally cylindrical in shape and has a generally circular cross-sectional shape. The post  58  is located radially between the projections  56  and spaced therefrom. The post  58  has a flange  60  extending radially outwardly from a free end thereof for a function to be described. The flange  60  may be a washer welded to the post  58  or be integral, unitary, and one-piece with the post  58 . It should be appreciated that the projections  56  orientate the air spring  21  to a predefined orientation and hold or guide a coil spring (not shown). It should also be appreciated that the flange  60  will hold the retaining member  46  and also a jounce bumper (not shown) for the coil spring when the jounce bumper is inside of the coil spring. 
     The upper spring seat  52  has a side wall or flange  62  extending downwardly and generally perpendicular thereto. The side wall  62  has a slot  64  therein for allowing access to the apertures  36  in the upper mounting cap  26 . The slot  64  is generally rectangular in shape. The upper spring seat  52  is connected to the frame  12  by a suitable mechanism such as welding or fasteners (not shown). The upper spring seat  52  is made of a rigid material, preferably a metal material. The upper spring seat  52  is a monolithic structure being integral, unitary, and one-piece. It should be appreciated that lower mounting cap  24  of the air spring  21  may be configured similar to the upper mounting cap  26  and that the lower spring seat  18  may be configured similar to the upper spring seat  52  such that the lower mounting cap  24  could be retained with the retaining member  46  to the lower spring seat  18 . 
     In operation of the air spring assembly  10 , the lower mounting cap  24  of the air spring  21  is attached to the lower spring seat  18 . The upper mounting cap  26  is attached to the upper spring seat  52  by locating the post  58  in the cavity  32 . The projections  56  are disposed in the channel  30  and orientate the air spring  21 . The retaining member  46  is slid through the apertures  36  and channel members  38  in the upper mounting cap  26  until the side portions  50  of the retaining member  46  passes over the cavity  32  and into the channel members  38  again on the opposite side of the cavity  32  which traps the post  58 . The base portion  48  of the retaining member  46  is pushed over the projections  44  of the tab  42 , which flexes and acts to self-retain the retaining member  46 . At this point, the tab  42  springs back and locks the air spring  21  in place. To remove the air spring  21 , the air spring diaphragm  22  is deflated and the tab  42  is depressed. The retaining member  46  is removed from the channel members  38  of the upper mounting cap  26  and the upper mounting cap  26  is moved in a direction opposite to insertion to remove to the post  58  and projections  56  from the cavity  32 , channel  30 , and the upper spring seat  52 . It should be appreciated that the operation may be repeated to re-assemble the air spring  21  to the seats  18  and  52 . It should also be appreciated that the channel members  38  are not open to an inner air chamber of the air spring  21 , which accomplishes a secure air tight locking mechanism with no threaded fasteners and can be used in a blind environment. 
     The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. 
     Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.