Patent Application
20090127919
The present disclosure relates to a wheel-balancing weight for balancing a wheel of a vehicle or the like. More particularly, the present disclosure relates to a wheel balancing weight with a unitary body and clip.
In the manufacture of pneumatic tires and also wheels and rims for pneumatic tires, it is exceedingly difficult if not impossible to produce a tire, a wheel, or the combination thereof in perfect rotational balance. As known, when out of balance, such a tire, wheel, or combination thereof, vibrates excessively upon rotation and can cause damage to adjacent, coupled to and/or related components. Moreover, when the tire and wheel are coupled to a moving vehicle such as a passenger car, the vibration can be uncomfortable to an occupant
Accordingly, and as is known, such tire, wheel, or combination thereof is balanced by appropriately applying one or more counter-balancing weights to compensate for a measured imbalance. Typically, although by no means absolute, in the case where a tire is mounted to a wheel of a vehicle, the wheel includes a circumferential flange or lip at a rim on either axial side thereof and a weight of appropriate mass is applied at each flange at an appropriate circumferential location thereof. Methods of measuring imbalance and determining where to apply the counter-balancing weights are generally known to the relevant public and therefore need not be described herein.
Heretofore, such a counter-balancing weight for a vehicle has been constructed to have a body forming the majority of the mass of the weight and a clip by which the body is secured to the flange of a wheel, where the clip is attached to the body by any of several attaching mechanisms. For example, the clip may be swaged to a face of the body or affixed to a face of the body by way of one or more screws, rivets, expansion bolts, or the like. Additionally, the body may be formed from a molten material such as lead or the like around a clip formed from sheet steel or the like.
Notably, though, the use of lead has come to be discouraged for environmental reasons, among others. Moreover, attaching the clip to the body requires numerous production steps, each of which can introduce complexity and error to the overall manufacturing process. Further, attaching separate components to form a weight introduces join or attachment issues, including the possibility of attachment failure at the attachment location and corrosion at such attachment location, particularly from water infiltrating the attachment location and flexing that may occur at such attachment location.
Accordingly, a need exists for a wheel-balancing weight with a clip and a body that is formed from a material other than lead, where the clip is attached to the body in a simplified manner and with reduced or eliminated join issues. More particularly, a need exists for such a wheel-balancing weight where the clip and body are formed as a unitary member with a reduced number of production steps. Still more particularly, a need exists for such a wheel-balancing weight that is formed as a unitary steel member based on a forming and tooling process and therefore is affordable in cost.
The aforementioned need is satisfied by a wheel-balancing weight for mounting to a wheel with a flange. The weight is formed as a unitary member having a unitary body and clip such that the clip as formed is attached to and emerges from the body as formed. The body provides a predetermined mass to the weight and the clip securely grasps the flange of the wheel to secure the weight thereto. The weight is formed by forming a slug to include a formed body portion corresponding to the body and a formed clip portion corresponding to the clip, and bending over at least a portion of the formed clip portion of the slug to form the clip.
The foregoing summary as well as the following detailed description of various embodiments of the present invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the various embodiments of the invention, there are shown in the drawings embodiments that are presently preferred. As should be understood, however, the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
Certain terminology may be used in the following description for convenience only and is not considered to be limiting. For example, the words “left”, “right”, “upper”, “lower”, “top”, “bottom”, “front”, and “back” designate directions in the drawings to which reference is made. Likewise, the words “inwardly” and “outwardly” are directions toward and away from, respectively, the geometric center of the referenced object. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.
As shown in
It is to be appreciated that the tire 10 may be mounted to the wheel 12 in any conventional or unconventional manner and that the tire 10 may be of any variety or manufacture without departing from the spirit or scope of the present invention. The tire 10 and wheel 12 or wheel 12 alone may be balanced manually or by spin balancing or by any other method without departing from the spirit and scope of the present invention.
As is known, a wheel 12 and a wheel 12 with tire 10 mounted thereupon are balanced with respect to the rotational axis thereof and in particular can be balanced on both the axially inboard and outboard sides of the wheel 12 at or about the rim 11 thereof. Generally, a wheel 12 with or without a tire 10 mounted thereupon is balanced by measuring the imbalance and then attaching a weighted mass or weight 20 at a circumferential location on the rim 11 of the wheel 12 such that the measured imbalance is counter-balanced by the weight 20. Such balancing is often performed on both the inboard and outboard sides of the wheel 12.
Typically, the rim 11 of a wheel 12 at each axial side thereof extends both axially and circumferentially. The wheel 12 also includes a central well portion (not shown) through which bolts on a vehicle typically extend to attach the wheel 12 to such vehicle. As seen in
Each flange 15 as shown may be constructed during formation of the wheel 12 by crimping or otherwise forming a portion of the rim 11 so as to create a generally axially extending lip 16. As seen in
It is to be recognized that the flange 15 may also have other dimensional features without departing from the spirit and scope of the present invention. As shown in the drawings, the flange 15 extends generally axially and generally radially outwardly in an S-shape as viewed in toroidal cross-section, but it should be understood that the flange 15 may extend in another direction. Additionally, the flange 15 may vary in dimension, location and in number, all without departing from the spirit and scope of the invention.
Typically, a wheel balancing weight 20 such as that shown in
In the prior art and as is shown in
Moreover, and again, attaching the clip to the body requires numerous production steps, each of which can introduce complexity and error to the overall manufacturing process. For example, each of the body 19 and the clip 21 must be formed with appropriate attaching features, each of which must be located with relatively high precision. Thereafter, the formed body 19 and the formed clip 21 must be appropriately co-located with respect to each other while attachment takes place. Note here that such attachment can take place by swaging, riveting (shown in
Additionally, attaching a separate body and clip 19, 21 to form a weight 10 introduces join or attachment issues, including the possibility of attachment failure at the attachment location and corrosion at such attachment location. For example, if swaging or riveting is performed with too much force, the body 19 or clip 21 may break, while screwing overly tightly can strip threads formed in the body 19 and result in the body 19 separating from the clip 21. Note too that if a screw or rivet is employed to attach the body and clip 19, 21, such screw or rivet can itself fail and also result in the body 19 separating from the clip 21.
Further, the attachment location at which the body and clip 19, 21 meet represents the point at which damage from corrosion is most likely to take place. As may be appreciated, such attachment location ca form a compartment that attracts and retains water, which is the main source of such corrosion. Also, such attachment location is where the clip 21 flexes with respect to the body 19 when strained, and such flexure can lead to cracking and metal fatigue at such attachment location.
Wheel-Balancing Weight with Unitary Clip and Body
Accordingly, and in various embodiments of the present invention, the attachment location is eliminated from the weight 20 by forming the weight as a unitary member having the body and clip 19, 21, as is shown in
As may be appreciated, the unitary weight 20 having both the body and clip 19, 21 as formed has a general shape and structure akin to that of prior art weights. Thus, the body 19 extends generally transversely and circumferentially for some distance that generally corresponds to a stated mass of the weight 20, and the clip also extends generally transversely, albeit a length that is usually less than that of the body 19. However, such shape and structure does differ based on the absence of any distinct attachment mechanism for attaching the body 19 to the clip 21, such attachment mechanism being unnecessary in the various embodiments of the present invention. Instead, the clip 21 as unitarily formed with the body 19 to form the weight 20 merges with such body 19.
As shown in
Notably, the body 19 may be formed to closely follow the lip 16 and brim 17 of the flange 15 of the rim 11 when the weight is mounted to such rim 11 at such flange 15. Thus, such body 19 is more intimately nestled within the pocket 18 defined by the flange 15 when the weight 20 is mounted to such flange 15 at an appropriate circumferential location thereof. As was set forth above, the weighted body 19 of the weight 20 should be well-nestled in such pocket 18 to achieve proper balancing. Accordingly, the body 19 extends in an arcuate manner so as to enhance such nestling in the generally circumferential pocket 18.
As also shown in
The clip 21 thus curves along with but is separable from the gripping portion of the inboard face of the body 19 such that the lip 16 of the flange 15 may be fitted and securely gripped therebetween. As a result, the clip 21 as shown in
For example, the clip 21 may emerge from the body 19 at an angle with respect to the outboard face of the body 19, as is shown in
In various embodiments of the present invention, and with reference to the actions set forth in
For example, the forming process may be a linear forming process such as an extrusion process, a rolling process, a drawing process, a combination of such processes, or the like. As may be appreciated, such a linear forming process has the benefit that the steel strip produced thereby can be of relatively long length and a correspondingly relatively large number of slugs may be cut therefrom, which as should be appreciated is advantageous in an operation where weights are to be produced in relatively high volume and/or at relatively high rates.
If an extrusion process, such extrusion process receives as an input a steel material, such as for example a steel wire, and outputs the steel strip (601 of
Cutting the slug 24 from the steel strip may be performed by any appropriate machinery without departing from the spirit and scope of the present invention. For example, such cutting may be performed by a powered shearing machine or by a laser, among other things. The length of the slug 24 as cut from the steel strip may vary based on the predetermined mass that the weight 20 produced from the slug 24 is to have. Thus, longer lengths correspond to increasing mass. As seen in
As best seen in
As also shown, the body portion 28 of the slug 24 is relatively thicker in depth from front to back (i.e., left to right in
Note that, as seen in
As should be understood, the clip 21 of a weight 20 is likely shorter in length than the body 19 of the weight 20, except when the mass of the weight 20 is relatively small such that the length of the body 19 is relatively short. Put another way, though the body 19 may require an extended length in order to impart a particular mass to a weight 20, the clip 21 of such weight 20 need not likewise have such an extended length to secure the weight 20 to a flange 15 of a rim 11. Moreover, inasmuch as the clip 21 is generally linear but is attached to an arcuate flange 15, it is likely more difficult for the clip 21 to grip the flange 15 as the length of such clip 21 increases.
Thus, and as should also be understood, the length of the clip 21 that results from the clip portion 26 of the slug 24 is likely to be reduced as compared to the length of such clip portion 26. Accordingly, and in various embodiments of the present invention, lateral wings 30 are defined in the clip portion as is seen in
As shown, the removed lateral wings 30 are generally rectilinear and thus are formed by cuts in the slug 24 that are generally parallel to the sides thereof. Such cutting of the lateral wings 30 from the slug 24 may be performed by any appropriate machinery without departing from the spirit and scope of the present invention. For example, such cutting may be performed by a powered snipping machine, by a laser, or by a stamping operation, among other things, and may occur immediately after the slug 24 has been cut from the aforementioned steel strip as was set forth above at 603.
After the lateral wings 30 have been removed from the slug 24 as in
As seen in
As also seen in
The bending of the reduced clip portion 26r to form the clip 21 and of the body portion 28 to form the body 19 as at 607 and 609 may be performed by any appropriate machinery without departing from the spirit and scope of the present invention. For example, such bending 607 and 609 may be performed by one or more powered pressing machines, and may be done serially or essentially simultaneously. If done serially, separate machines or a single machine may be employed, and either the body 19 or the clip 21 may be bent first. If done simultaneously, a single machine would be employed. In either case where a single machine is employed, such single machine would of course include both the mechanism for bending the reduced clip portion 26r to form the clip 21 as at 607 and the mechanism for bending the body portion 28 to form the body 19 as at 609. Additionally, such bending of the body 19 and the clip 21 may occur immediately after the lateral wings 30 have been removed from the slug 24 as was set forth above as at 605.
Note here that the weight 20 can be formed from the slug 24 essentially within a single machine if such single machine is constructed to perform all of the actions as set forth above. Alternately, at least some of the actions can be performed by such a single machine. Notably, such a single machine could perform at least some of the actions on the slug 24 at a single station within such machine, and without moving same from one station to another. Thus, registering and positioning the slug 24 at such a single station need only be performed once, and errors from multiple registrations and positionings may be avoided. For example, it may be that cutting the lateral wings 30 as at 605 and bending the body 19 and clip 21 as at 607 and 609 may be performed at such single station.
Note too that in an alternate embodiment of the present invention, the slug 24 as formed is not generally linear but instead is formed such that the body portion 28 thereof is already generally arcuate. Forming such an arcuate formed slug is known or should be apparent to the relevant public and therefore need not be set forth herein in any detail. If already arcuate as formed, the body portion 28 of the slug 24 need not be bent as at step 609.
Once the final shape of the weight 20 with the body 19 and the clip 21 has been arrived at, as is shown in
As thus far set forth herein, the weight 20 having the unitary body 19 and clip 21 is formed from a steel material. However, such a unitary weight 20 may also be formed from any other appropriate material without departing from the spirit and scope of the present invention. Note, though, that steel is presently preferred, especially inasmuch as steel is relatively pliable and may be formed and bent with relative ease to form the weight 20, and also inasmuch as a steel clip 21 can be formed with relative ease to maintain the spring thereof without substantial loss or fatigue.
It is to be noted that by forming a weight 20 having a unitary body 19 and clip 21 in the manner set forth above, it has been estimated that a single production line can produce about 100 formed weights 20 per minute, if not more. Such a rate of production is believed to be a considerable improvement over previous processes, and particularly processes that involved casting the body 19 separately from the clip 21, where the production rate for a single production line is about 20-50 per minute.
In the foregoing description, it can be seen that the present invention comprises a new and useful wheel-balancing weight 20 with a unitary body 19 and clip 21 formed from a material such as a formed steel. The clip 21 is attached to the body 19 in a simplified manner by being formed with such body 19 and emerging therefrom, and with reduced or eliminated join issues. The clip 21 and body 19 are formed as a unitary member with a reduced number of production steps, and based on a forming and tooling process that is affordable in cost and high in production rate.
It should be appreciated that changes could be made to the embodiments described above without departing from the inventive concepts thereof. For one example, the clip 21 may emerge from the body 19 at an alternate location. For another example, the presence of a tire 10 is not essential to the present invention and the invention encompasses the use of the wheel-balancing weight 20 to counter-balance the wheel 12 only. It should be understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
