Abstract:
A vehicle wheel weight includes a mass portion cold-formed of nonlead material adapted to be juxtaposed against a wheel rim. The mass portion defines a clip securement cavity formed therein which is seamless at its respective ends. A clip made of spring steel is also provided. The clip has an attachment portion inserted into and retained in the clip securement cavity such that an end of the attachment portion is located entirely within the mass portion and the clip is fixed to the mass portion. The clip further has an extended portion for engaging the wheel rim.

Description:
PRIORITY CLAIM 
   This application is a continuation of application Ser. No. 10/724,000, filed Nov. 26, 2003 now abandonded, which is continuation-in-part of application Ser. No. 10/620,309, filed Jul. 15, 2003 now abandonded, 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. These applications to which Applicant claims priority are relied upon and incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to wheel balance weights. 
   In order to reduce excessive vibration, vehicle wheels are often balanced by placing weights at selected locations. The weights include a mass portion which is attached to the wheel&#39;s rim using a spring clip or a suitable adhesive. Due to high mass and low cost, such weights have been made of lead. Because of various factors, however, it is becoming desirable to manufacture such weights of materials other than lead. 
   SUMMARY OF THE INVENTION 
   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. Many embodiments are attached to the wheel using a spring clip preferably made of spring steel. In such embodiments, a depression or groove may be formed in the center section of the mass with a width that matches the spring clip as required to achieve the desired fit during assembly. Depth of the groove may match the spring clip thickness or be slightly greater. The depth match would continue around the mass surface as required to provide a nest for the clip. 
   In accordance with other embodiments of the present invention, the weight may comprise a mass portion configured as a strip of one or more interconnected weight segments having adhesive on a back surface thereof. For example, the adhesive may be provided by double-sided tape located on the back surface of the strip. Preferably, the release liner of the tape will extend a short distance beyond the longitudinal end of the strip so as to provide a pull tab at this location. The segments are defined and interconnected by grooves formed in the nonlead material. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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: 
       FIG. 1A  is a front elevational view of a vehicle wheel weight constructed in accordance with a first embodiment of the present invention; 
       FIG. 1B  is a cross sectional view taken along line  1 B— 1 B of  FIG. 1A  showing the wheel weight further mounted to the rim of a wheel; 
       FIG. 1C  is a bottom view of the wheel weight of  FIG. 1A ; 
       FIG. 2A  is a cross sectional view of the mass portion of a vehicle wheel weight in accordance with the present invention made solely of a nonlead material such as iron or low carbon steel; 
       FIG. 2B  is a cross sectional view similar to  FIG. 2A  but showing a mass portion made of an outer sheath of nonlead material with lead on the inside; 
       FIG. 3A  is a front elevational view of a vehicle wheel weight constructed in accordance with a second embodiment of the present invention before material for retaining the clip is swaged into place; 
       FIG. 3B  is a cross sectional view taken along line  3 B— 3 B of  FIG. 3A ; 
       FIG. 3C  is a bottom view of the wheel weight of  FIG. 3A ; 
       FIG. 3D  is a view similar to  FIG. 3A  but with the retaining material swaged into place; 
       FIG. 3E  is a cross sectional view taken along line  3 E— 3 E of  FIG. 3D ; 
       FIG. 3F  is an enlarged cross sectional taken along line  3 F— 3 F of  FIG. 3D ; 
       FIG. 4A  is a front elevational view of a vehicle wheel weight constructed in accordance with a third embodiment of the present invention; 
       FIG. 4B  is a cross sectional view taken along line  4 B— 4 B of  FIG. 4A ; 
       FIG. 4C  is an enlarged cross sectional taken along line  4 C— 4 C of  FIG. 4A ; 
       FIG. 5A  is a front elevational view of a vehicle wheel weight constructed in accordance with a fourth embodiment of the present invention; 
       FIG. 5B  is a cross sectional view taken along line  5 B— 5 B of  FIG. 5A ; 
       FIG. 5C  is an enlarged cross sectional taken along line  5 C— 5 C of  FIG. 5A ; 
       FIG. 6A  is a front elevational view of a vehicle wheel weight constructed in accordance with a fifth embodiment of the present invention; 
       FIG. 6B  is a cross sectional view taken along line  6 B— 6 B of  FIG. 6A ; 
       FIG. 6C  is an enlarged cross sectional taken along line  6 C— 6 C of  FIG. 6A ; 
       FIG. 7A  is a front elevational view of a vehicle wheel weight constructed in accordance with a sixth embodiment of the present invention; 
       FIG. 7B  is a cross sectional view taken along line  7 B— 7 B of  FIG. 7A ; 
       FIG. 7C  is an enlarged cross sectional taken along line  7 C— 7 C of  FIG. 7A ; 
       FIG. 8A  is a front elevational view of a vehicle wheel weight constructed in accordance with a seventh embodiment of the present invention; 
       FIG. 8B  is a cross sectional view taken along line  8 B— 8 B of  FIG. 8A ; 
       FIG. 8C  is a bottom view of the wheel weight of  FIG. 8A ; 
       FIG. 9  is a perspective view diagrammatically illustrating one technique for producing the mass portion of nonlead wheel weights in accordance with the present invention; 
       FIGS. 9A and 9B  are cross-sectional views of the mass material at the locations indicated by lines  9 A— 9 A and  9 B— 9 B, respectively; 
       FIG. 10  is a plan view diagrammatically illustrating the steps that take place at the forming station indicated by line  10 — 10  of  FIG. 9 ; 
       FIGS. 11A and 11B  illustrate an eighth embodiment of a vehicle wheel weight constructed in accordance with the present invention; 
       FIG. 12A  is a side elevational view of a tape-on version of a vehicle wheel weight constructed in accordance with the present invention; 
       FIG. 12B  is a plan view of the wheel weight of  FIG. 12A ; 
       FIG. 12C  is an enlarged view of the portion so indicated in  FIG. 12A ; 
       FIG. 12D  is an enlarged end view of the wheel weight of  FIG. 12A ; 
       FIG. 13  is an enlarged fragmentary view of an alternative tape-weight constructed in accordance with the present invention; 
       FIG. 14A  is a side elevational view of a further tape-on weight constructed in accordance with the present invention; 
       FIG. 14B  is a plan view of the wheel weight of  FIG. 14A ; 
       FIG. 14C  is an enlarged end view of the wheel weight of  FIG. 14A ; 
       FIG. 14D  shows a vehicle wheel in section, with the wheel weight of  FIG. 14A  mounted thereto; 
       FIG. 15A  an exploded view of a vehicle wheel weight constructed according to another embodiment of the present invention; 
       FIG. 15B  is a perspective view of the vehicle wheel weight of  FIG. 15A ; 
       FIG. 15C  is a side cross sectional view taken along line  15 C— 15 C of  FIG. 15B ; 
       FIG. 16A  is a perspective view of a vehicle wheel weight having a partially cut-away portion to show mass portion constructed according to another embodiment of the present invention; and 
       FIG. 16B  is a side cross sectional view taken along line  16 B— 16 B of  FIG. 16A . 
   

   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 
   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. 
     FIGS. 1A through 1C  illustrate a vehicle wheel weight  10  constructed in accordance with a first embodiment of the present invention. As shown, wheel weight  10  includes a mass portion  12  to which a spring clip  14  is attached. As shown, clip  14  (which may be made from spring steel) is located in a groove  16  which has a depth preferably equal to or slightly greater than the thickness of clip  14 . As can be seen in  FIG. 1B , clip  14  serves to attach weight  10  to the rim  18  of a vehicle wheel. 
   As shown, clip  14  is preferably configured as a C-shaped member such that it “wraps around” mass portion  12  on the side opposite to rim  18 . Clip  14  is retained in this case by one or more spot welds (such as spot weld  20 ) at suitable locations. For example, the spot weld may be made at the point on the clip most distant from the wheel rim flange. This is to prevent tempering of the spring steel of clip  14  near the location where the wheel rim is to be engaged. 
   Mass portion  12  is preferably made from a nonlead material having suitable mass, such as iron, low carbon steel or an impregnated polymeric. (See U.S. Pat. No. 6,364,422 to Sakaki et al., incorporated herein by reference.) In  FIG. 2A , mass portion  12  is preferably made entirely of iron or low carbon steel. Often, a 1008 steel will be especially preferred.  FIG. 2B  illustrates an alternative mass portion  12 ′ in which an outer sheath  22  of nonlead metal is filled with lead  24 . In this way the lead component is encased within a skin of steel or other suitable rugged material. 
     FIGS. 3A through 3F  illustrate a wheel weight  30  constructed in accordance with another embodiment of the present invention. As shown, weight  30  includes a mass portion  32  and a spring clip  34 . In this case, clip  34  is attached via raised portions  36  ( FIGS. 3A–3C ) of mass material located at the sides of the groove in which clip  34  is seated. Raised portions  36  are then swaged over top of clip  34  (as indicated at  38  in  FIGS. 3D–3F ) to cause an interference fit with the clip. 
     FIGS. 4A through 4C  illustrate a wheel weight  40  constructed in accordance with a further embodiment of the present invention. Weight  40  includes a mass portion  42  defining a groove into which a spring clip  44  is seated. Unlike the embodiment of  FIGS. 3A–3F , this embodiment does not utilize a raised area beside the groove. Instead, the sides of the groove are swaged into the clip at points with a staking technique (as indicated at  46 ) to give a “stitched look.” 
   A further embodiment of a wheel weight  50  constructed in accordance with the present invention is illustrated in  FIGS. 5A through 5C . Weight  50  includes a mass portion  52  defining a groove into which a spring clip  54  is seated. As indicated at  56 , the sides of the groove are swaged into the clip as described above except that a “wedge” is used to cause the top of the groove to close. 
   Referring now to  FIGS. 6A through 6C , a wheel weight  60  constructed in accordance with a further embodiment of the present invention is illustrated. Weight  60  includes a mass portion  62  defining a groove into which a spring clip  64  is seated. In this case, the spring clip  64  may be approximately L-shaped (rather than C-shaped as in previous embodiments). As indicated at  66 , an interference fit is created by providing the clip with serrated edges which are pressed into a groove having a width slightly less than the clip width. In this embodiment, it may be optionally desirable to also perform some swaging of material to further secure the interference fit. 
     FIGS. 7A through 7C  illustrate a wheel weight  70  constructed in accordance with a further embodiment of the present invention. Weight  70  includes a mass portion  72  defining a groove into which an L-shaped spring clip  74  is seated. To secure the two components, an indention is defined in each side of the clip. In this case, for example, the indention is formed as a ⅓ circle. As indicated at  76 , the groove is swaged enough to force metal into the indention as well as over the top of the clip. 
     FIGS. 8A through 8C  illustrate a further embodiment in which a wheel weight  80  is constructed in accordance with the present invention. It can be seen that weight  80  is similar to weight  10 , except the mass portion  82  and spring clip  84  are joined with a suitable adhesive (as indicated at  86 ) instead of spot welding. Although a strip of structural adhesive as shown in the drawing may often be sufficient, in many cases it will be desirable to apply the adhesive liberally over the mating surfaces. 
   Referring now to  FIGS. 9–10 , one method of producing the mass portion from iron or low carbon steel will be described. This method utilizes raw material that is either round in cross-section or preformed with a shape that is either the same as or is substantially similar to the cross-section of the mass portion to be formed (such as round for a wheel balance weight). One “piece” of raw material would contain enough material for numerous wheel weight masses. This may be either a long rod  90  or a coil  92  with enough material for hundreds or thousands of finished mass portions. 
   In this case, the mass forming machinery comprises three subsystems working together. These may be described as follows: 
   1. Material handling and supply  94 —Either an “uncoiler” or rod feeding equipment is provided to deliver the raw material (e.g., iron). 
   2. Forming rolls  96  and  98  (or other suitable rolling machine) are provided to form the long (wheel size) radius and pre-form the shape that will fit into the rim flange. The amount of pre-forming would be inversely proportional to the size of press being used. 
   3. A metal forming press  100  is used to finish the rim flange shape, form a groove for the wheel balance weight clip, stamp product information into the surface, and cut to the required length. The press working surfaces would be a die that may be progressive or not depending on press size and part details. A large press forming a large part may be able to form all surfaces and cut to length in one stroke. Alternatively, small parts may need to be made in a progressive fashion to get all forming surfaces to bear on a small area. A small press could form a large part by using a progressive die and distributing the work over more than one press cycle. 
   As an alternative to the details shown in  FIG. 10 , it may be desirable in some cases to form the cut-off “Preform” prior to “Shape Finishing.” In fact some of the die operations might be done before the die. The die could then be a stamping/trim die. 
   Finally, suitable corrosion protection materials may be applied after assembling the mass and clip. Other finishing may or may not be required depending on customer finishing requirements. 
     FIGS. 11A and 11B  illustrate a further embodiment of a wheel weight  110  constructed in accordance with the present invention. Weight  110  includes a mass portion  112  defining a cavity  114  in which spring clip  116  is inserted. Specifically, mass portion  112  may be cold formed with cavity  114  form fitted inside the body of the weight. This will eliminate the need for having the clip extend over either the front or back of the clip. Preferably, the attachment portion of the spring clip includes at least one surface irregularity, here in the form of a pair of holes  115 , to facilitate retention of the attachment portion therein. When the securement cavity is closed after insertion of the attachment portion of the spring clip, a small hump  117  remains due to the thickness of the clip. 
     FIGS. 12A–12D  illustrate an alternative embodiment in which the weights may be attached to the wheel rim using an adhesive coating (i.e., a tape-on weight). Preferably, the mass portions are formed as a flexible string of nonlead mass material having a predetermined number of segments. A covering (i.e., a release liner) which protects the adhesive is removed when it is desired to attached the mass portion(s) to the wheel. The illustrated embodiment has several significant features, including: (1) deep grooves formed into its surface to make the string conformable to different size wheels, and (2) a unique pull tab arrangement. 
   As can be seen, tape-on weight  120  includes a mass portion formed as a strip  122  of suitable nonlead material. Strip  122  is divided into a plurality of segments  124  defined by respective grooves  126 . Groove  126  is formed as deep as possible, while leaving a small uncut zone  128  at the bottom. Zone  128  permits the string to be flexed so as to conform to the arc of the rim to which it is to be attached. Each of the segments  124  will preferably have a predetermined weight, such as 5 grams. 
   In this embodiment, the adhesive is provided in the form of a two-sided tape  130  attached to the bottom surface of string  122 . Preferably, tape  130  will include a conformable carrier of foam or the like having adhesive on each side. A release liner  132  is located on the back side of tape  130  so as to cover the adhesive until use. As illustrated in  FIG. 12D , the release liner may actually be formed as two pieces of tape  132 A and  132 B configured to provide pull tabs for easy removal. In this case, liner portion  132   a  is folded back on itself as shown in  FIG. 12D . 
     FIG. 13  illustrates an alternative embodiment of a tape weight  140  constructed in accordance with the present invention. Weight  140  includes a mass portion formed as a strip  142  of weight segments  143  defined by transverse grooves  145 . Groove  145  is configured to leave a small uncut zone  146  near the bottom of strip  142 . A double-sided tape  147  is located on the back side of strip  142 . A release liner  148  is provided behind double-sided tape  147  so as to protect the adhesive. 
   A small tab  149  connected to (or integral with) release liner  148  extends from the longitudinal end of strip  142  so as to facilitate removal of release liner  148 . In this case, tab  149  is formed as a separate piece of tape which overlaps the end of release liner  148  (as indicated at  150 ) and overlaps itself (as indicated at  151 ). Silicone tapes are believed to be particularly suitable for tab  149 . 
   Generally, weight  140  will be sold in a variety of different numbers of segments depending upon the total weight to be achieved. For example, a typical construction may have two to six segments of 5 grams each. As a result, total weight will fall in a range of 10–60 grams. Larger weight sizes may also be desirable in certain applications. 
   Preferably, zone  146  will be as thin as possible in order to provide for greatest flexibility. For example, embodiments are contemplated in which the thickness of zone  146  is about three thousandths of an inch. Generally, the thickness would not exceed twenty thousandths in presently preferred embodiments. 
   It is also desirable that the width of groove  145  be substantial so as to prevent surface treatment bridging which adds stiffness to the overall weight. Specifically, the weight may be subjected to a variety of surface treatments in order to reduce corrosion and the like. For example, zinc plating (or zinc phosphate wash) followed by epoxy powder and painting may be employed. Making groove  145  of sufficient width will prevent these surface treatments from adding significant stiffness to the overall weight. In presently preferred embodiments, the width of groove  145  will typically be at least fifty thousandths of an inch at its widest point (the mouth). Often, widths of around 130 thousandths will be preferred. 
   Referring now to  FIGS. 14A–14D , a further embodiment of a tape-on weight constructed in accordance with the invention is illustrated. As can be seen, tape-on weight  160  is made of non-lead material, such as iron or low carbon steel. The mass portion  162  of weight  160  is preformed in an arc having a radius approximating that of the surface to which it is to be mounted. Dimensions (such as length) of the wheel weight are determined based on the desired mass. In addition, the weight must not be made of a size (e.g., thickness and width) such that it would interfere with the operation of other vehicle parts. 
   An adhesive (here in the form of a double-sided tape  164 ) is located on the outer diameter of mass portion  162 . Although mass portion  162  will generally be rigid, the presence of the adhesive will provide a degree of elasticity (conformability) to accommodate varying wheel diameters. The adhesive is protected prior to use using a release liner  166 , which is in this example similar to release liner  132  ( FIG. 12D ). 
     FIGS. 15A through 15C  illustrate a wheel weight  170  constructed in accordance with another embodiment of the present invention. As shown, weight  170  includes a mass portion  172  and a spring clip  174 . In this case, a longitudinal slot  176  is defined in mass portion  172  to receive the end portion of clip  174 . For example, mass portion  172  could be formed with a “V” shaped cross section. It should be appreciated that multiple mass portions could be formed by cutting an elongated piece having a slot into multiple segments. 
   Clip  174  is inserted into slot  176  of mass portion  172 . To fix the position of clip  174  in slot  176 , mass portion  172  is crimped together to cause an interference fit, thereby embedding clip  174  into mass portion  172 . Preferably, clip  174  has surface irregularities  178 , such as a hole, groove or indentation, to which mass portion  172  can grip to aid in fixing the position of clip  174 . As shown in  FIG. 15C , for example, mass portion  172  deforms into surface irregularities  178  of clip  174  during crimping. 
     FIGS. 16A and 16B  illustrate a wheel weight  180  constructed in accordance with another embodiment of the present invention. As shown, weight  180  includes a mass portion  182  and a spring clip  184 . In this case, a protective sleeve  186  surrounds mass portion  182  and fixes the position of clip  184 . For example, sleeve  186  could be injection-molded plastic. Prior to injection molding, clip  184  and mass portion  182  could be loosely arranged together. However, the injection molding fixes the position of clip  184  so that it can not move. Moreover, mass portion  182  is protected from the environment by sleeve  186  to prevent corrosion. 
   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 as further described in the appended claims.