Patent Publication Number: US-2007102246-A1

Title: Hub hat for bolt-on brake rotor, associated brake assembly and associated methods

Description:
FIELD OF THE INVENTION  
      The present invention relates to the field of auto/truck parts, and, more particularly, to brake assemblies and related methods.  
     BACKGROUND OF THE INVENTION  
      The average pick-up truck utilizes ½ ton axles with a 29″ to 31″ tall tire on a 7″ wide wheel. These axles were designed to withstand typical loads. As off-road enthusiasts began mounting larger tires and wider wheels on these trucks the additional leverage often resulted in axle failure. This led to the use of stronger ¾ &amp; 1 ton axles. Some off-road trucks began using 48″ tall tires with a 25″ tread width mounted on 20″ wide wheels. The leverage factor simply proved too great for even the strongest 1 ton axles. The spindles, steering knuckles and king pins were never designed for these loads. So, many off-road enthusiasts began using ‘Rockwell 2½ ton’ military troop transport axles. In addition to having stronger knuckles and king pins, these axles had a third member which was inserted from the top side of the axle housing (“Top Loader”) which included a 90 degree pinion thus reducing driveline angles. These axles also were equipped with a 6.72:1 gear ratio which worked very well with the 48″ tire combo.  
      However, this military running gear, as well as other after-market heavier duty axle assemblies, includes drum brakes. Disc brakes are superior to drums in numerous ways. They offer better stopping power and are self cleaning in mud and water, where drums tend to pack up with dirt and moisture. The rotor of a disc brake assembly is exposed to air which helps keep them cooler for less fade. Disc brake assemblies also weigh less and are easier to service than drum brakes. For example, typical drum brakes include various springs and a manual adjuster which are susceptible to failure under certain off road conditions.  
      So, various disc brake conversion kits are available. However, these kits typically include specialized rotors including welded-on hub hats and various brackets to complete the conversion. There is a need for a bolt-on disc brake assembly that can be used with off the shelf rotors and doesn&#39;t require any welding.  
     SUMMARY OF THE INVENTION  
      In view of the foregoing background, it is therefore an object of the present invention to provide a bolt-on disc brake assembly including a hub hat that can be used with off the shelf rotors and doesn&#39;t require any welding to complete a disc brake conversion.  
      This and other objects, features, and advantages in accordance with the present invention are provided by a hub hat for mounting a bolt-on brake rotor to a wheel hub on an axle shaft assembly. The hub hat includes an annular hub plate with circumferentially spaced through-holes to receive wheel studs of the wheel hub, an annular rotor plate with circumferentially spaced through-holes to receive bolts for bolting on the brake rotor, and a circular-cylindrical hub housing connected between the annular hub plate and the annular rotor plate.  
      The circular-cylindrical hub housing may include a first open end coupled to the annular hub plate, and a second open end opposite the first open end and coupled to the annular rotor plate. The annular hub plate has an inner diameter and an outer diameter, and the annular rotor plate has an inner diameter and an outer diameter. The first open end of the circular cylindrical hub housing may include a first stepped portion fitted within the inner diameter of the annular hub plate, and the second open end of the circular cylindrical hub housing may include a second stepped portion fitted within the inner diameter of the annular rotor plate.  
      The circular-cylindrical hub housing may include a first hub housing portion adjacent the annular hub plate and having a first outer diameter, a second hub housing portion adjacent the annular rotor plate and having a second outer diameter less than the first outer diameter, and a transition portion, such as a beveled portion, between the first and second hub housing portions.  
      Objects, features, and advantages in accordance with the present invention are provided by a bolt-on brake assembly to be mounted on an axle shaft assembly, and including a bolt-on brake rotor, a wheel hub including wheel studs, and a hub hat to mount the bolt-on brake rotor to the wheel hub. The hub hat includes an annular hub plate including circumferentially spaced through-holes to receive the wheel studs of the wheel hub, an annular rotor plate including circumferentially spaced through-holes to receive bolts for bolting on the brake rotor, and a circular-cylindrical hub housing connected between the annular hub plate and the annular rotor plate. A brake caliper is mounted adjacent the bolt-on brake rotor, and a brake caliper mounting bracket may be included to mount the brake caliper to the axle shaft assembly adjacent the bolt-on brake rotor.  
      Objects, features, and advantages in accordance with the present invention are also provided by a method for mounting a bolt-on brake rotor to a wheel hub on an axle shaft assembly. The method includes providing a hub hat by forming an annular hub plate with circumferentially spaced through-holes to receive wheel studs of the wheel hub, forming an annular rotor plate with circumferentially spaced through-holes to receive bolts for bolting on the brake rotor, and connecting the annular hub plate and the annular rotor plate with a circular-cylindrical hub housing.  
      The method may also include bolting the bolt-on brake rotor on the annular rotor plate, mounting the hub hat to the wheel hub via the wheels studs, and mounting the hub hat and wheel hub on the axle shaft assembly. Also, a brake caliper may be mounted adjacent the bolt-on brake rotor via a mounting bracket connected to the axle shaft assembly.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a plan view of a hub hat and brake rotor in accordance with the present invention.  
       FIG. 2  is a side view of the annular hub plate of the hub hat of  FIG. 1 .  
       FIG. 3  is is a side view of the annular rotor plate of the hub hat of  FIG. 1 .  
       FIG. 4A  is a side view of the circular-cylindrical hub housing of the hub hat of  FIG. 1 .  
       FIG. 4B  is a top view of the circular-cylindrical hub housing of  FIG. 4A .  
       FIG. 5A  is a side view of the brake rotor of  FIG. 1 .  
       FIG. 5B  is a top view of the brake rotor of  FIG. 5A .  
       FIG. 6  is a side view of a brake caliper mounting bracket in accordance with the invention.  
       FIG. 7  is a top view of the bolt-on brake assembly and wheel hub mounted on an axle shaft assembly in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation is used to indicate similar elements in alternative embodiments.  
      Referring to  FIGS. 1-7 , a bolt-on disc brake assembly  90  including a hub hat  10  will be described. The bolt-on disc brake assembly  90  including a hub hat  10  can be used with off the shelf brake rotors and doesn&#39;t require any welding to complete a disc brake conversion. The hub hat  10  is for mounting a bolt-on brake rotor  40  to a wheel hub  80  on an axle shaft assembly  60 . The hub hat  10  includes an annular hub plate  12  with circumferentially spaced through-holes  18  to receive wheel studs  82  of the wheel hub  80 . The hub hat  10  also includes an annular rotor plate  14  with circumferentially spaced through-holes  19  to receive bolts  44  for bolting on the brake rotor  40  via brake rotor mounting holes  42 . Furthermore, a circular-cylindrical hub housing  16  is connected between the annular hub plate  12  and the annular rotor plate  14 .  
      The circular-cylindrical hub housing  16  may include a first open end coupled to the annular hub plate  12 , and a second open end opposite the first open end and coupled to the annular rotor plate  14 . The annular hub plate  12  has an inner diameter A, e.g. about 7.105 inches, and an outer diameter B, e.g. about 10.5 inches, and the annular rotor plate  14  has an inner diameter C, e.g. about 7.0 inches, and an outer diameter D, e.g. about 8.35 inches. The first open end of the circular cylindrical hub housing  16  may include a first stepped portion  28 , having a diameter H (e.g. about 7.1 inches), fitted within the inner diameter A of the annular hub plate  12 , and the second open end of the circular cylindrical hub housing may include a second stepped portion  20 , having a diameter I (e.g. about 6.99 inches) fitted within the inner diameter C of the annular rotor plate  14 . The annular hub plate  12  and the annular rotor plate  14  are each preferably mounted via a precision fit with respective stepped portions  28 ,  20 . The annular hub plate  12 , annular rotor plate  14  and cylindrical hub housing  16  are preferably secured to each other via respective welds to provide an integrated hub hat  10  to the consumer.  
      The circular-cylindrical hub housing  16  may include a first hub housing portion  26  adjacent the annular hub plate  12  and having a first outer diameter F (e.g. about 7.4 inches), a second hub housing portion  22  adjacent the annular rotor plate  14  and having a second outer diameter G (e.g. about 7.18 inches) less than the first outer diameter F, and a transition portion  24 , such as a beveled portion having an angle M, between the first and second hub housing portions. The transition portion  24  provides the clearance for easing the installation of the wheel studs  82  and/or rotor mounting bolts  44 . The width J of the cylindrical hub housing  16  may be about 2.75 inches, for example.  
      The bolt-on brake assembly  90  is designed to be mounted on an axle shaft assembly  60 , such as Rockwell 2½ ton military gear. Of course the hub hat  10  and bolt-on brake assembly  90  of the present invention may be used with any axle assembly and wheel hub combination that can be converted and/or upgraded to disc brakes. The bolt-on brake assembly  90  includes the bolt-on brake rotor  40 , a wheel hub  80  including wheel studs  82 , and the hub hat  10  to mount the bolt-on brake rotor  40  to the wheel hub  80 . A brake caliper  70  ( FIG. 7 ) is mounted adjacent the bolt-on brake rotor  40 , and a brake caliper mounting bracket  50  ( FIGS. 6 and 7 ) may be included to mount the brake caliper, via caliper mounting holes  52 , axle assembly mounting holes  54  and bolts  56 ,  58 , to the axle shaft assembly  60  adjacent the bolt-on brake rotor  40 .  
      A method aspect of the invention is directed to mounting the bolt-on brake rotor  40  to the wheel hub  80  on an axle shaft assembly  60 . The method includes providing a hub hat  10  by forming the annular hub plate  12  with circumferentially spaced through-holes  18  to receive wheel studs  82  of the wheel hub  80 , forming the annular rotor plate  14  with circumferentially spaced through-holes  19  to receive bolts  44  for bolting on the brake rotor  40 , and connecting the annular hub plate and the annular rotor plate with a circular-cylindrical hub housing  16 .  
      The method may also include bolting the bolt-on brake rotor  40  on the annular rotor plate  14 , mounting the hub hat  10  to the wheel hub  80  via the wheels studs  82 , and mounting the hub hat  10  and wheel hub  80  on the axle shaft assembly  60 , e.g. on spindle  84 . Also, the brake caliper  70  may be mounted adjacent the bolt-on brake rotor  40  via the mounting bracket  50  connected to the axle shaft assembly  60 .  
      Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.