Abstract:
A valve assembly for use in an air brake system is provided. The assembly includes a modulator housing, a valve assembly, and a clamp for holding the valve assembly in an operative position on the modulator housing. One leg of the clamp is fit over retaining bosses on the housing. Another leg of the clamp is bent or advanced toward a retainer that cooperates with a retaining opening on the leg to maintain the clamp in a tensioned state and secure the valve assembly to the modulator housing.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to an improved clamp assembly and, more specifically, to an improved clamp assembly for holding a solenoid pack to a modulator housing for tractor trailer brake systems. However, it will be appreciated that the present invention is also amenable to other like applications.  
           [0002]    A need exists for a new clamping assembly, particularly one that resolves problems associated with securing a solenoid valve assembly to a modulator housing as used in an air brake system for heavy vehicles. The modulator housing is usually a cast and machined component, for example a die cast aluminum part. Openings are provided in the housing to receive a solenoid pack used to effect antilock braking features for the brake system. The solenoid pack typically includes first and second solenoid valve assemblies that are encased in a plastic over-molded material. Unfortunately, space constraints, manufacturing concerns, and magnetic property considerations led to development of a solenoid pack that had no attachment mechanism. However, an effective, robust, and reliable attachment of the solenoid pack to the modulator housing is required. Moreover, the clamping arrangement must not damage the solenoid pack which thereby limits known clamping structures that would adversely impact on the plastic construction of the solenoid pack.  
         SUMMARY OF THE INVENTION  
         [0003]    The present invention provides a clamp assembly that robustly clamps a solenoid pack to a modulator housing without damaging same and without using fasteners.  
           [0004]    In accordance with one aspect of the present invention, a preferred clamp assembly for use in an antilock brake system is provided. The clamp assembly cooperates with a modulator housing, a valve assembly, and specifically employs a spring clamp for holding the valve assembly in an operative position on the modulator housing.  
           [0005]    In accordance with another aspect of the present invention, the assembly includes a raised boss and a raised tab on the modulator housing. The clamp assembly further comprises a first leg that engages the raised tab of the modulation housing. A second leg is disposed generally perpendicular to the first leg and a third leg includes an opening that engages the raised boss of the modulator housing. The third leg is dimensioned to be in parallel, tensioned relation relative to the first leg upon engagement with the modulator housing.  
           [0006]    In accordance with yet another aspect of the present invention, a method of holding a valve assembly to a modulator housing by means of a clamp is provided. The clamp includes a first leg defining openings thereon, a second leg extending therefrom and interconnecting the first leg with a third leg having engagement means defined thereon. The second leg is disposed substantially perpendicular to the first and third legs. The method comprises the step of positioning the valve assembly on the modulator housing wherein clamp openings are aligned with raised bosses of the modulator housing. A force is applied to the clamp to secure the valve assembly to the modulator housing and cause the engagement means of the clamp to fasten onto a raised tab of the modulator housing. The clamp elastically deforms and maintains a force against the valve assembly onto the modulator housing.  
           [0007]    One advantage of the present invention resides in a simple design to clamp a solenoid pack to a modulator housing.  
           [0008]    Another advantage of the present invention is found in the ability to securely hold a solenoid pack to a modulator housing.  
           [0009]    Still further benefits and advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating the presently preferred embodiments and are not to be construed as limiting the invention.  
         [0011]    [0011]FIG. 1 is a perspective view of a clamp assembly in accordance with the present invention.  
         [0012]    [0012]FIG. 2 is another perspective view of the clamp assembly shown in FIG. 1.  
         [0013]    [0013]FIG. 3 is a perspective view of the modulator housing of FIG. 1.  
         [0014]    [0014]FIG. 4 is another perspective view of the modulator housing of FIG. 1.  
         [0015]    [0015]FIG. 5 is a perspective view of the clamp of FIG. 1.  
         [0016]    [0016]FIG. 6 is another perspective view of the clamp of FIG. 1.  
         [0017]    [0017]FIG. 7 is an elevational view, partly in cross-section, of the clamp of FIG. 1 in an unclamped position.  
         [0018]    [0018]FIG. 8 is an elevational view of the clamp assembly of FIG. 1 in a clamped position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    With reference to FIGS. 1 and 2, a modulator valve assembly incorporating a new clamp assembly as generally indicated by reference numeral  10 . The assembly comprises a modulator housing  12 , a valve assembly or solenoid pack  14 , and a clamp  16  for holding the valve assembly in position on the modulator housing. Preferably, the clamp is a stamped spring component while the modulator housing is cast aluminum and the solenoid pack includes a plastic overmolded housing. Of course, other alternative materials or constructions can be used without departing from the scope and intent of the present invention. The general structure and operation of a modulator valve of this type in an air braking system is generally known in the art so that a discussion of the detailed aspects of the modulator valve and solenoid valves associated with ABS features of the brake system form no part of the present invention and therefore will not be described herein.  
         [0020]    With additional reference to FIGS. 3 and 4, the modulator housing  12  includes a substantially flat or planar portion  18  for receiving the solenoid pack  14 . The modulator housing also includes a housing  20  that is formed at one end defining a set of valve chambers  22  for interacting with the solenoid pack  14 . A plurality of openings  24  are disposed along spaced peripheral portions of the modulator housing for securing the modulator housing to a relay valve (not shown) via fasteners (not shown).  
         [0021]    A pair of raised bosses  26  are preferably disposed at central locations near the edges of the modulator housing  12  for engagement with the clamp  16 . Of course other mounting locations can be used without departing from the scope and intent of the present invention. The raised bosses  26  which are integrally joined to the housing are machined, for example, along an outer periphery to form a first component securing the clamp to the modulator housing. The machining operation maintains a desired tolerance and allows for a precise fit between the raised bosses  26  and the clamp  16  as will be described further below.  
         [0022]    With reference back to FIGS. 1 and 2, the solenoid pack  14  includes an electrical connection  28  at one end and solenoid valve interfaces (not shown) at another end for interacting with the valve chambers  22  of the housing  20 . The solenoid pack  14  overlies the substantially planar portion  18  of the modulator housing and abuts against the housing  20 .  
         [0023]    Reference is made to FIGS. 5 and 6 which illustrate details of the clamp  16 . The clamp  16  includes a first section or leg  30 , a second section or leg  32 , and third section or leg  34 . The first leg  30  has an opening or window  36  adjacent a distal end that serves as one component of retaining means as will be described in greater detail below. The first leg also has an opening  38  between the distal end thereof and the opening  36  that is dimensioned to receive a fastener device for additional positive retention of the clamp in place as required by regulation.  
         [0024]    The first leg  30  extends generally perpendicular relative to the second leg  32  and is generally parallel to the third leg  34 . More specifically, and with additional reference to FIG. 7, the first leg  30  is slightly angled relative to the third leg, e.g., at five degrees in the preferred embodiment. The second leg, likewise, forms an angle with the third section  34 , for example on the order of eighty-five degrees. It will be appreciated, however, that the invention should not be limited to the particular angles as shown and described.  
         [0025]    A curved section  40  interconnects the first leg to the second leg. In the preferred arrangement, the first and second legs  30 ,  32  include an enlarged opening  42  (FIGS. 5 and 6) formed therethrough for receiving the electrical connector  28  of the solenoid pack. Thus, one end of the first leg and the entire second leg are defined by first and second portions. It will be appreciated by one skilled in the art that the particular configuration of the first and second legs must accommodate the solenoid pack and provide the desired flexibility/rigidity of the clamp, although other configurations that serve these purposes are also contemplated.  
         [0026]    The third leg  34  includes openings  44  in each leg portion for engagement with the raised bosses  26  of the modulator housing. More specifically, the third leg is defined by a pair of flange members that each have a respective opening  44 . The flange members are located at either side of the clamp  16 .  
         [0027]    A support flange  48  extends in an opposite direction relative to the third leg  34 . The support flange  48  is generally parallel to the third leg and adds rigidity and additional strength to the clamp.  
         [0028]    The clamp  16  is preferably a stamped construction that is capable of being elastically deformed for locking engagement with the modulator housing. More specifically, the first leg  30 , second leg  32 , and interconnecting curved portion  40  are placed in tension and urge the clamp to securely and lockingly engage the solenoid pack to the modulator housing with a sufficient compressive force. Simultaneously, the clamp does not damage the plastic material that forms a portion of the solenoid pack.  
         [0029]    To assemble, the solenoid pack  14  is positioned on the modulator housing  12 . More specifically, the solenoid pack is positioned on the modulator housing such that the solenoid valve interfaces with the valve chambers  22  in the modulator housing.  
         [0030]    Next, the clamp  16  is positioned over the solenoid pack  14  and on the modulator housing  12 . Particularly, the clamp is aligned such that the electrical connector  28  of the solenoid pack extends through the opening  42  of the clamp. Further, the openings  44  of the clamp are aligned to receive the raised bosses of the modulator housing therethrough.  
         [0031]    When properly aligned, a load or force F is then applied to the curved section  40  of the clamp. The first and second legs elastically deform as a result of the load and the first leg  30  of the clamp is driven downwardly and forwardly from the position shown in FIG. 7 as represented by the unnumbered dashed line. The opening  36  of the clamp engages and snaps over a raised tab  46  on the modulator housing thus securely engaging the solenoid pack to the modulator housing. (See FIG. 8). The deformed clamp is prevented from being lifted over the raised tab  46  because of the spring force exerted by the deformed legs  30 ,  32  against the raised tab.  
         [0032]    A fastener  50  is added through the opening  38  of the clamp and secured in an opening  52  (FIGS. 3 and 4) on the modulator housing. The fastener is not necessary to securely maintain the solenoid pack on the modulator housing. Nonetheless, the fastener is included as a redundant locking feature to further maintain the clamp in position against the solenoid pack.  
         [0033]    With reference to FIG. 8 the completed assembly of the clamp is shown. Notably, the clamp  16  is fully engaged with the modulator housing and the solenoid pack is securely held in position thereon. More specifically, the openings  44  receive the raised bosses  26  of the modulator housing. Also, the opening  36  of the clamp is securely engaged to the raised tab  46  of the modulator housing. The first leg  30  is held in parallel relation to the third leg  34  and the second leg  32  is perpendicular to both of the first and third legs  30 ,  34 .  
         [0034]    The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof.