Abstract:
An improved system and method for mounting an air dryer is provided. The improved system and method employs a single centralized special fitting that secures the air dryer manifold to a reservoir. The bore in which the fitting is disposed is used to communicate air from the reservoir to the air dryer in order to purge the desiccant in the air dryer. The mounting assembly includes anti-rotational mechanisms which prevent the air dryer from rotating about its axis. The mounting assembly may also include a reservoir and a mounting bracket for the reservoir which uses less than 75 percent of a truck mounting rail height.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a mounting assembly for an air dryer, and more specifically to a mounting assembly for an air dryer for a commercial vehicle.  
         [0003]     2. Discussion of the Art  
         [0004]     In compressed air braking systems, such as those used on commercial vehicles, an air dryer is typically placed in line after the compressor and prior to the rest of the components, such as the compressed air reservoir or air brake units. The air dryer removes harmful contaminants, such as dirt, oil, oil vapor, water and water vapor, from the compressed air, and thus provides clean, dry air to the components of the brake system. Clean dry air increases the reliability and life of the brake system, thereby reducing maintenance costs.  
         [0005]     One issue that remains constant with regard to commercial vehicle air dryers is how to provide a better mounting arrangement so as to minimize the space consumed by the air dryer. In most commercial vehicles, mounting space is very limited. An improved mounting arrangement could free up valuable space for other components. Furthermore, the mounting arrangement of an air dryer defines the parameters used to design the air flow path to and from the air dryer. A more efficient air flow path can make the air dryer more effective and reduce the space required for mounting the air dryer assembly.  
       SUMMARY OF THE INVENTION  
       [0006]     An improved air dryer mounting assembly is provided. The improved assembly provides for mounting assembly provides for many different mounting arrangements. Furthermore, the air dryer mounting assembly unifies the mounting apparatus with a purge passageway to provide a more compact and efficient air dryer assembly.  
         [0007]     In one embodiment, the improved system includes a manifold and a desiccant cartridge. A central bore runs through the manifold wherein a fitting is disposed. A purge flow can communicate from a purge volume to the desiccant through the fitting bore. In one embodiment, the purge volume is disposed within a reservoir to which the air dryer is attached.  
         [0008]     Other aspects of the present invention is an improved method of drying air and an improved method for mounting an air dryer. In an exemplary embodiment, an air dryer with a central bore is attached to a purge reservoir with a specialized fitting. The purge reservoir communicates with the air dryer through the central bore. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1A  is a prospective view of an air dryer assembly employing the single fastener method of mounting of the present invention;  
         [0010]      FIG. 1B  is a prospective view of an air dryer assembly employing a two fastener method of mounting of the present invention;  
         [0011]      FIG. 2  is an exploded view of the air dryer assembly shown in  FIG. 1A ;  
         [0012]      FIG. 3  is a prospective view of the back of the air dryer assembly shown in  FIG. 1A ;  
         [0013]      FIG. 4  is a prospective view of an air dryer manifold used in connection with the air dryer assembly shown in  FIG. 1A ;  
         [0014]      FIG. 5  illustrates the mounting of the air dryer of  FIG. 1A  on another air reservoir embodiment; and  
         [0015]      FIG. 6  illustrates a sectional view of the reservoir as shown in  FIGS. 1A &amp; 1B ;  
         [0016]      FIG. 7  illustrates a sectional view of another embodiment of the reservoir as shown in  FIGS. 1A &amp; 1B , with a different threaded joint to receive an air dryer;  
         [0017]      FIG. 8  illustrates the mounting arrangement of the air dryer shown in  FIGS. 1, 6  and  7  on a truck frame rail;  
         [0018]      FIG. 9  is a perspective view of an air dryer assembly employing the two fastener method of mounting of the present invention;  
         [0019]      FIG. 10  is an exploded view of the air dryer assembly shown in  FIG. 9 ;  
         [0020]      FIG. 11  is a prospective view of the back of the air dyer assembly shown in  FIG. 9 ;  
         [0021]      FIG. 12  is a prospective view of an air dryer manifold used in connection with the air dryer assembly shown in  FIG. 9 ;  
         [0022]      FIG. 13  illustrates a section view of the reservoir as shown in  FIG. 9 ; and  
         [0023]      FIG. 14  illustrates the mounting of the air dryer of  FIG. 9  on another air reservoir embodiment.  
         [0024]      FIG. 15  illustrates a section view of the reservoir as shown in  FIG. 9 , wherein an alternative threaded member is illustrated. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]     The invention is a mounting assembly for an air dryer. A single fitting or two or more fittings may be used to secure the air dryer body. As such, the air dryer can be secured to various locations on the vehicle, including reservoir surfaces which are not flat. The mounting arrangement takes advantage of a central mounting arrangement of the air dryer and employs means for preventing rotation. Furthermore, the assembly includes a uniform passageway that retains a securing fitting and also acts as the purge volume passageway. The description included below will be directed to embodiments of this invention.  
         [0026]     As shown in  FIG. 1 , the single fitting air dryer assembly  10  includes an air dryer manifold  20 , an air dryer canister  25 , and a specialized fitting, fastener or bolt,  30 . One skilled in the art should appreciate that the bolt, fastener or specialized fitting  30  can be any type of fitting such as to affix the manifold  20  to the vehicle, and as such the terms bolt, fastener and fitting should not be construed as limiting the type of attachment means included within the scope of this application. For example, it is contemplated that the fastener may be threaded or non-threaded or can be a quick-connect fastener or push-to-connect fastener. As discussed further herein, the assembly may also include a reservoir  40 .  
         [0027]     The manifold  20  and air dyer canister  25  can be a variety of conventional components. The air dryer canister  25  is a conventional desiccant canister with a set of threads running through an opening on the underside of the cartridge that receives a set of mating threads protruding from the center of the air dryer manifold  20 . Preferably, but not necessarily, the threads are between 36 mm and 50 mm. In one embodiment, the threads are 41 mm, while in another embodiment, the threads are 42 mm. Optionally, an adapter can be used to make the canister  25  with 50 mm threads adapt to 39 mm standard threads, for example. The air dryer manifold  20  can have any number of inlet and outlet ports  45 , four such ports are shown in  FIGS. 1 and 4 . In one embodiment, the air dryer manifold  20  includes a purge valve  50  and a check valve  54 , while other embodiments include just a purge valve  50  or just a check valve  54 . The air dryer manifold  20  can be made entirely from plastic or it can be made from plastic with metallic inserts, or in other embodiments, the manifold can be made from metal. Examples of the plastic that can be used to make the air dryer manifold  20  include Nylon 6, Delrin or accetel.  
         [0028]     The manifold  20  includes a central bore  60  and a mounting extension  42 . The central bore  60  has a front end  65  containing a recessed surface  67  and a back end  69  that extends through the extension  42  and forms a recessed surface  70 . The recessed surface can be any suitable shape including, but not limited to, circular, ovular, or tear-drop shaped. This mounting arrangement can take advantage of a central mounting arrangement of the air dryer assembly, thereby only requiring one connective bolt  30 . The bolt, or fastener,  30  slides through the bore  60  such that the head of the bolt  30   a  contacts the recessed surface  67 , which may optionally include an o-ring. The threads of the bolt are received either onto a mounting bracket (not shown) or, preferably, into a threaded connection  74  in a reservoir  40 . The reservoir  40  includes a purge hole  68  that aligns with a purge hole extension  66  in the back end  69  of the central bore  60 . This allows for communication between the air dryer manifold  20  and the purge volume in the reservoir  40  and also allows for a tight connection between fastener  30  and the reservoir  40 . Additionally, a gasket (not shown) can be placed along the perimeter of the back end  69  of the central bore  60  thereby providing a good air tight seal. It should be appreciated by one skilled in the art that the purge hole  68  can connect to the central bore  60  in other manners, such as, for example, direct overlap of the purge hole and the central bore or an extension of the reservoir hole  74  to overlap the central bore or purge hole extension  68 .  
         [0029]     In order to prevent the air dryer from rotating about its central axis, position stabilizers may be used to secure the air dryer. The type of position stabilizer used can vary. One such embodiment employs interlocking retention pegs (not shown) extending from recessed surface  70  and along reservoir hole  74 . When the air dryer manifold  20  is secured against the head  75  of the reservoir, the corresponding pegs engage to prevent rotation of the manifold  20  with respect to the reservoir  40 . In another embodiment, the retention pegs are only located along reservoir hole  74  and interlock with edges formed in the recessed surface  70 . In another embodiment, as best shown in  FIGS. 1 and 3 , the extension  42  includes two arms  83  that form a generally u-shaped area  84 . The head  75  of the reservoir  40  includes a projection  86  which resets between the arms  83  in the u-shaped area  84  when the manifold is brought into contact with the reservoir  40 . When projection  86  is secured between arms  83 , the manifold  20  cannot rotate about its axis. In another embodiment, as best shown in  FIGS. 9 and 11 , the extension  42  includes a tab  91  with a hole  93  therein, through which a secondary bolt  95  can pass. The secondary bolt can thread into a second threaded hole or connection  96  in the reservoir  40 . As shown in  FIGS. 13 and 15 , the treaded connection  96  can be a rivet nut. Other embodiments use combinations of these stabilizing elements, or other mechanisms.  
         [0030]     As shown in  FIG. 6 , the reservoir hole  74  can open into the interior  97  of the reservoir such as to allow the bolt  30  to connect through to the threaded connection  99  located at the back of the reservoir  40 . This type of connection provides additional support and prevents deformation of the head  75  of the reservoir. In  FIG. 7 , the threaded connection  99  can be located at the front of the reservoir  40 . It should be understood by one skilled in the art that the threaded connection  99  can be any number of connections, such as, for example, a rivet nut, a plus nut, or a ferrule projection welded onto the interior surface of the reservoir. Some illustrative examples are shown in  FIGS. 13 and 15 . The reservoir  40  may include an embossment  100  on the head  75  in order to facilitate mounting of the air dryer.  FIGS. 1A &amp; 1B  shows the one such embossment  100 , while  FIG. 9  shows another embossment embodiment. Additionally, the reservoir  40  may be divided into two or more sections, divided by bulk heads. In this manner, the most forward section acts as the purge reservoir for the air dryer  10 , while the other sections of the reservoir can be used for other purposes, such as the primary or secondary service brake reservoirs. Additionally, as shown in  FIG. 13 , a support plate  101  can be fastened or welded to the interior surface of the reservoir in order to provide further support.  
         [0031]     The bolt  30  intersects the flow path through the air dryer manifold  20  such that the air may pass through the bore  60  along the bolt threads and into or out of the reservoir  40 . The bolt  30  may be a special fitting to assist in this functionality. Such a special fitting would includes threads, a counter-bore (not shown) and a cross-drilled hole (not shown) that would allow the dryer to access the purge volume locate in the reservoir  40 . The special fitting eliminates the need for an external line to connect the air dryer  10  with the purge volume located in the reservoir  40 .  
         [0032]     As shown in  FIG. 8 , the reservoir  40  can be mounted to a truck rail  120  in a much more efficient method. The reservoir  40  includes mounting bracket  130  with two mounting holes  132  which is directly welded to the reservoir. Unlike conventional mounting brackets, the mounting bracket  130  of the present invention can be employed without the need of the additional brackets and straps which make conventional air dryer mounting brackets cumbersome and more expensive. Furthermore, mounting bracket  130  is much smaller than conventional mounting brackets. As a result, space d is freed up along the truck rail  120 . While conventional mounting brackets use 80-100 percent of the truck rail height h, mounting bracket  130  can use less than 75 percent, and preferably less than 50 percent. Depending on the truck rail employed, it is conceived that the mounting rail  130  can consume as little as 15 to 30 percent of the truck rail height h and still adequately secure the reservoir  40  and air dryer assembly  10 .  
         [0033]     As such, this disclosure provides for an improved mounting assembly for an air dryer. The air dryer includes a central bore  60  wherein a special fitting  30  is threaded. The fitting  30  is then received into the reservoir  40 , preferably the center of the reservoir head  75  to ensure stability. The air dryer  40  is aligned so that position stabilizers secure the air dryer and prohibit it from rotating along its central axis. The fitting  30  is then tightened down to provide for secure mounting of the air dryer  10 . The fitting  30  is further adapted to allow for communication between the air dryer  10  and the reservoir  40  through the central bore  60 .  
         [0034]     The air dryer assembly also provides for improved air drying, as the first air through the air dryer can be stored in the purge volume and, once the purge volume is full, then supply air downstream. During the purge cycle, the purge volume is depleted, using the first air that was dried by the air dryer and thereby providing the driest air for regenerating the desiccant. This method of drying air is further disclosed in commonly assigned U.S. Pat. No. 6,585,806 issued Jul. 1, 2003, the disclosure of which is hereby fully incorporated by reference.  
         [0035]     The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon a reading and understanding of the detailed description. The invention is intended to include all such modifications and alterations insofar as they come within the scope of the accompanying claims and the equivalents thereof.