Metal working – Method of mechanical manufacture – Wheel making
Reexamination Certificate
1999-10-21
2002-10-15
Echols, P. W. (Department: 3726)
Metal working
Method of mechanical manufacture
Wheel making
C029S527700, C164S098000
Reexamination Certificate
active
06463660
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates in general to vehicle wheels and in particular to a process for fabricating a two piece vehicle wheel which includes forming a wheel disc upon the outboard end of a partial wheel rim.
It is known in the art to fabricate a two piece vehicle wheel by attaching a wheel disc to a separately formed wheel rim. Typically, the wheel disc is cast or forged while the rim is rolled or spun from strip stock. Such two piece wheels are less expensive to manufacture than a cast one piece wheel while permitting use of stylistic designs for the wheel disc.. Both the wheel disc and rim can be formed from alloys of the same light weight metal, such as aluminum, magnesium or titanium, or, as a further cost reduction, a wheel disc formed from an alloy of a light weight metal can be attached to a rim rolled from steel. When different metals are used to form the wheel disc and wheel rim, the wheel is commonly called a bimetal wheel.
To further improve the appearance of the wheel, the wheel disc can be formed to include the outboard tire bead retaining flange. The resulting wheel disc, which is called a full face wheel disc, is attached to the outboard end of a partial wheel rim. The attachment can occur at the outboard tire bead seat, the deepwell, or another location. The assembled wheel is often referred to as a full face wheel. When a tire is mounted upon a full face wheel, the joint between the wheel disc and wheel rim is completely hidden and only the wheel disc is visible. A decorative finish is often applied to the face of the wheel disc to further enhance the appearance of the wheel. Examples of typical decorative finishes include metal plating, such as chromium plating, paint and clear coatings.
Referring now to the drawings, there is shown in
FIG. 1
a fragmentary sectional view of a typical prior art full face wheel
10
. The wheel includes a full face wheel disc
11
formed from a light weight metal or light weight metal alloy by a conventional process, such as gravity, low pressure or die casting, or forging. The full face wheel disc
11
includes a wheel hub
12
having a central pilot hole
13
and a plurality of wheel lug holes
14
(one shown) formed therethrough. The hub
12
is supported by a plurality of wheel spokes
15
(one shown) within an annular sidewall
16
. An outboard tire bead retaining flange
17
extends in a radial outward direction from the sidewall
16
. An outboard tire bead seat
18
is formed in the sidewall
16
adjacent to the retaining flange
17
. The sidewall
16
further includes an outboard tire safety bead
19
formed between the tire bead seat
18
and a cylindrical collar
20
which forms a portion of a deepwell
21
. The collar
20
extends axially from the inboard surface of the sidewall
16
.
A conventional partial wheel rim
23
is attached to the inboard side of the wheel disc
11
. The wheel rim
23
can be formed from a strip of light weight metal or steel with conventional rim roll forming machinery. The wheel rim
23
includes a cylindrical outboard end
24
which forms a portion of the deepwell
21
. A leg portion
24
extends axially from the drop well
21
to an inboard tire safety bead
26
. An inboard tire bead seat
27
is formed adjacent to the safety bead
26
. The inboard end of the wheel rim
24
terminates in a conventional inboard tire bead retaining flange
28
.
An air-tight continuous circumferential weld
29
is formed between the outboard end of the wheel rim
24
and the wheel disc collar
20
. The weld
29
shown in
FIG. 1
is formed by a conventional electron beam or arc welding process. Alternately, a conventional friction or inertial welding process can be used to form the weld
29
. During the friction welding process, the wheel disc
11
is held stationary while the wheel rim
23
is rotated with the outboard rim end
24
pressed against the wheel disc collar
20
The heat generated by friction partially melts the outboard wheel rim end
24
and the adjacent portion of the collar
20
to form the weld
29
. For a bimetal wheel, a ring-shaped weld anchor (not shown) formed from a ferrous material, such as steel, can be partially embedded in the wheel disc sidewall
16
. A portion of the weld anchor is exposed to form a welding surface.
Referring now to
FIG. 2
, there is shown a flow chart for a known manufacturing process for fabricating the full face wheel illustrated in FIG.
1
. In functional block
30
a full face wheel disc is formed by a conventional process, such as casting or forging. The wheel disc is heat treated in functional block
31
and then machined to final shape in functional block
32
.
While the wheel disc is being formed, a flat strip of metal is rolled into a circular hoop and the ends butt welded together in functional block
35
. The hoop is formed into a partial wheel rim in functional block
36
by a conventional process, such as rolling or spinning.
In functional block
37
, the partial wheel rim is attached to the wheel disc formed in functional blocks
30
through
32
by a conventional welding process. The wheel rim is usually welded to the wheel disc. Typically, it is difficult to weld the hoop coaxially with the wheel disc axis so that the inboard and outboard tire bead seats are concentric to one another. If the outboard and inboard tire bead seats of the assembled wheel are outside the required tolerance limits for concentricity, undesirable vibrations may occur when the wheel is mounted upon a vehicle and the vehicle operated. Accordingly, the tire bead seats of the assembled wheel are machined in functional block
38
to assure that the required amount of concentricity is achieved.
SUMMARY OF THE INVENTION
This invention relates to an improved process for fabricating a two piece vehicle wheel which includes forming a wheel disc upon the outboard end of a partial wheel rim.
As described above, a two piece vehicle wheel is typically fabricated by welding a preformed wheel rim to a finished wheel disc. It is usually difficult to weld the rim concentrically onto the disc. Accordingly, it would be desirable if a two piece wheel could be fabricated without welding. It would also be desirable to eliminate the weld between the wheel rim and wheel disc to simplify the manufacturing process while reducing costs.
The present invention contemplates a process for fabricating a vehicle wheel which includes an annular hoop of metal. The metal hoop is then in a wheel disc mold and a wheel disc is cast on the end thereof. The wheel disc casting and metal hoop are removed from the wheel disc mold and finished to form a vehicle wheel. The finishing can include forming the metal hoop into a wheel rim and machining the wheel disc casting. The metal hoop can be either cylindrical or flared.
The invention further contemplates that wheel disc mold defines a mold cavity and further that the mold can includes at least one optional supplemental heating element. During the casting operation, the supplemental heating element supplies additional heat to the mold cavity. Additionally, either the mold or the hoop can be optionally vibrated during the casting operation.
Alternately, the metal hoop can be mounted in die set for forging a wheel disc. A heated metal billet is placed into the die set and the die set closed to forge a wheel disc upon an end of the metal hoop. The hoop and wheel disc are then removed from the die set and the hoop formed into a wheel rim.
The invention also contemplates casting or forging a wheel disc upon the outboard end of a partial wheel rim.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
REFERENCES:
patent: 4487456 (1984-12-01), Zulauf
patent: 4773467 (1988-09-01), Graham et al.
patent: 4977947 (1990-12-01), Boswell et al.
patent: 5433511 (1995-07-01), Wei
patent: 5526977 (1996-06-01), Wei
Echols P. W.
Hayes Lemmerz International Inc.
MacMillan Sobanski & Todd LLC
LandOfFree
Process for forming a vehicle wheel disc directly upon a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for forming a vehicle wheel disc directly upon a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for forming a vehicle wheel disc directly upon a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2989658