Abstract:
A vehicle wheel weight comprises a mass portion cold-formed of nonlead material and a heat-treated spring clip. The mass portion has a front and a back, with the back adapted to be juxtaposed against a wheel rim. The mass portion further defines at least one chamfer on the back thereof. The mass portion also defines a clip securement pocket in which an attachment portion of the spring clip is inserted such that the clip is fixed to the mass portion. The clip further has an extended portion for engaging the wheel rim.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
       [0001]    This application is a continuation of copending application Ser. No. 11/324,784 (“the &#39;784 application”), filed Jan. 3, 2006, which claims the benefit of provisional application Ser. No. 60/641,110, filed Jan. 3, 2005, which is hereby relied upon and incorporated herein by reference. The &#39;784 application is also a continuation-in-part of application serial no. 11/304,126, filed Dec. 15, 2005, which is a continuation of application Ser. No. 10/724,000, filed Nov. 26, 2003, which is a continuation-in-part of application Ser. No. 10/620,309, filed Jul. 15, 2003, which claims the benefit of provisional application Ser. No. 60/396,075, filed Jul. 15, 2002, and provisional application Ser. No. 60/411,961, filed Sep. 19, 2002. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to wheel balance weights. 
         [0003]    In order to reduce excessive vibration, vehicle wheels are often balanced by placing weights at selected locations. One type of known weight includes a mass portion which is attached to the wheel&#39;s rim using a spring clip. Due to high mass and low cost, such weights have been primarily made of lead in the past. For example, such weights have been made by casting molten lead around a heat-treated spring clip. As a result, a portion of the clip would be embedded inside the mass portion, whereas another portion would extend out from the mass for attachment to a wheel rim. 
         [0004]    Because of various factors, it is becoming desirable to manufacture such weights of materials other than lead. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides a variety of configurations for a vehicle wheel weight. Preferred embodiments utilize iron or low carbon steel for mass instead of lead as has generally been used in the past. The mass is attached to the wheel using a spring clip preferably made of spring steel. The spring clip includes an attachment portion secured to the mass portion by an interference fit. For example, a pocket may be formed in the mass to receive the attachment portion of the spring clip. After the attachment portion is inserted, the pocket may be closed such that the spring clip is securely retained. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which: 
           [0007]      FIG. 1  is a front plan view of a vehicle wheel weight constructed in accordance with the present invention. 
           [0008]      FIG. 2  is a back plan view of the wheel weight of  FIG. 1 . 
           [0009]      FIG. 3  is a side view of the wheel weight of  FIG. 1 . 
           [0010]      FIG. 4  is a cross-sectional view along line  4 - 4  of  FIG. 1  showing the wheel weights mounted to a vehicle rim. 
           [0011]      FIGS. 5A-5C  are cross-sectional views of a mass portion in accordance with the present invention showing insertion of the spring clip in a cold-formed pocket. 
           [0012]      FIG. 6  is an enlarged view of the portion so indicated in  FIG. 5B  showing an elongate groove formed in the attachment portion of the spring clip. 
           [0013]      FIG. 7  is a fragmentary view showing the attachment portion of an alternative spring clip having a series of spaced apart louvers formed therein. 
           [0014]      FIG. 8  is a cross-sectional view taken along line  8 - 8  of  FIG. 7 . 
       
    
    
       [0015]    Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0016]    It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions. 
         [0017]      FIGS. 1 through 3  illustrate a vehicle wheel weight  10  constructed in accordance with an embodiment of the present invention. As shown, wheel weight  10  includes a mass portion  12  to which a spring clip  14  is attached. As will be explained more fully below, clip  14  (which is preferably made from spring steel) is located in a cavity (or “pocket”) formed in mass portion  12 . This often results in a slightly raised surface  16  on the “front” of mass portion  12 . (As used herein, the front of weight  10  is the side facing away from the wheel rim.) As can be seen, mass portion  12  has an arc approximating the circumference of the rim to which it will be attached. 
         [0018]    As indicated at  18  and  20 , indicia is preferably provided on mass portion  12  to indicate the weight&#39;s mass and/or type. Typically, the indicia is formed by stamping onto the mass so as to be permanent. The use of such indicia on vehicle wheel weights is common, but it has previously been provided on the front. Placing indicia on the back provides a more aesthetically pleasing product because it will be hidden during use. 
         [0019]    Mass portion  12  is preferably made from a nonlead material having suitable mass, such as iron or low carbon steel. Often, a 1008 steel will be especially preferred. In some cases, particularly weights of higher masses, copper may also be utilized. 
         [0020]    Referring now to  FIG. 4 , clip  14  serves to attach weight  10  to the rim  22  of a vehicle wheel. As shown, mass portion  12  is preferably configured so as to tuck neatly under the curved lip of rim  22 . It can be seen that mass portion  12  has a cross-sectional profile with smooth external surfaces about its circumference. This is in contrast in many weights of the prior art which exhibited rough edges. In addition to providing a more aesthetically pleasing appearance, such a configuration tends to minimize rim damage caused by sharp surfaces. 
         [0021]    In this case, mass portion  12  is desirably also configured to define a top chamfer  24  and a bottom chamfer  26 . Chamfers  24  and  26  are formed as relatively flat sloped surfaces extending axially along the back of mass portion  12 . 
         [0022]    Chamfer  24  facilitates attaching weight  10  by minimizing the amount of stretch required in clip  14  to properly seat mass portion  12  under the rim lip. Chamfer  26  provides clearance for various features that are seen in modern rims, such as spoke  28 . 
         [0023]      FIGS. 5A-5C  illustrate one manner in which clip  14  may be attached in accordance with the present invention. In this regard,  FIG. 5A  shows a cross-sectional view of mass portion  12  before installation of clip  14 . Mass portion  14  is preferably made from a “wire” that has been preformed with the desired cross-sectional profile. For example, chamfers  24  and  26  could be defined in the wire at the time of manufacture. A predetermined length of wire is then cut and formed with the desired arc to yield mass portion  12 . 
         [0024]    Referring now to  FIG. 5B , it can be seen that a pocket  30  has been formed in mass portion  12 . Pocket  30  is preferably cold-formed by inserting a lance having the appropriate configuration into the top of mass portion  12 . Pocket  30  is preferably formed to be closed at both ends, such as by web  32  (and a similar web at the other end). A mechanically applied zinc (or other suitable coating or treatment) can be applied after the lancing step to form a protective coating on mass portion  12 . 
         [0025]    After pocket  30  has been formed, the attachment portion  34  of clip  14  is inserted therein. Extended portion  36  of clip  14  remains outside of mass portion  12  for engaging the rim. 
         [0026]    Referring now to  FIG. 5C , pocket  30  is forced closed (as indicated by arrow  38 ) after insertion of attachment portion  34 . As a result, clip  14  will be strongly secured to mass portion  12 . 
         [0027]    Referring now to  FIG. 6 , it will often be desirable to provide attachment portion  34  of clip  14  with features that enhance the engagement between mass portion  12  and clip  14 . In this regard,  FIG. 6  illustrates an embodiment wherein an axial groove  40  is defined across the front surface of attachment portion  34 . When pocket  30  is closed, metal of the mass portion will flow into groove  40  to form an interference fit. 
         [0028]      FIGS. 7 and 8  illustrate an alternative embodiment, where a plurality of spaced apart louvers  42  are punched into attachment portion  34  of clip  14 . Louvers  42  also serve to provide secure engagement between mass portion  12  and clip  14  in a manner similar to groove  40 . 
         [0029]    Applicant hereby refers to related applications Ser. Nos. 10/724,000, filed Nov. 26, 2003 and 10/620,309, filed Jul. 15, 2003, both of which are commonly assigned. Each of these copending applications is incorporated fully herein by reference. 
         [0030]    The use of a cold-formed pocket for attaching clip  14  to mass portion  12  is desirable for a number of reasons. For example, casting a steel mass in a manner similar to that of lead weights would cause loss of the heat treatment on the clip. In addition, such a technique would not generally be economical. 
         [0031]    While an embodiment utilizing a single clip is shown, one skilled in the art will appreciate that larger mass portions may require more than one clip spaced apart along its axial length. 
         [0032]    While preferred embodiments of the invention have been shown and described, modifications and variations may be made thereto by those of ordinary skill in the art without departing from the spirit and scope of the present invention. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention defined in the appended claims.