Multiple torsion spring and methods of use

Details Multiple torsion spring and methods of use Multiple torsion spring and methods of use

1999-09-21

2001-04-24

Oberleitner, Robert J. (Department: 3613)

Spring devices

Torsion

Coil

C267S168000, C267S180000

Reexamination Certificate

active

06220586

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to multiple torsion springs. The springs of the present invention may be used in various applications, but are particularly suitable for effecting closure of a throttle valve of a throttle body or carburetor of an automobile internal combustion engine.
BACKGROUND OF THE INVENTION
Use of springs and spring assemblies for effecting throttle valve operation is well known in the art. Reference may be made to Blanchard et al. U.S. Pat. No. 4,582,653, which is incorporated herein by reference, for a more detailed disclosure of a typical throttle body equipped with a spring assembly for returning a throttle valve toward a closed position.
FIGS. 1-3
illustrate a prior art single torsion spring assembly
10
. The spring assembly
10
is described in detail in Pavlin U.S. Pat. No. 5,368,283 which is incorporated herein by reference. The spring
10
is referred to herein as a single torsion spring because it is coiled from a single strand of music wire. Reference is also made to Paggeot U.S. Pat. No. 4,828,235 which describes a similar single torsion spring, and which is also incorporated herein by reference.
The spring assembly
10
is shown in
FIGS. 1-2
in conjunction with a throttle body
11
of an automobile internal combustion engine. The throttle body
11
includes a lever
12
supported to rotate about the axis of a shaft
13
(FIG.
2
). Rotation of the lever
12
in one direction effects opening of the throttle valve (not shown) of the throttle body
11
, while reverse rotation of the lever
12
by the spring assembly
10
effects closing of the throttle valve.
The spring assembly
10
includes a coiled torsion spring
15
having two coils
15
A adjacent each end of the spring and a pair of end bushings
16
and
17
(FIG.
3
). The torsion spring
15
is wound helically from round music wire and is formed with the end coils
15
A being of a reduced diameter. The end coils
15
A of the single torsion spring are of equivalent diameter, albeit reduced from the diameter of intermediate coils. Tangs
24
and
25
extend radially from the coils. One tang is parallel to a longitudinal axis of the spring.
A dual torsion spring, that is a spring comprising two coiled strands, may be produced by coiling the two strands about a coiling shaft (or simply shaft). The dual torsion spring is then slid off of the shaft. Such a shaft wound dual torsion spring is not capable of having two reduced reduce end coils, one on either side of the intermediate coils. Further, one reduced end coil is difficult to achieve via a shaft wound method. These limitations are a result of the fact that a spring wound as such on a shaft cannot be slid off of the shaft after it is formed without deforming it.
Recently dual torsion springs having reduced end coils, wherein the end coils are of equivalent diameters, have become known in the art.
FIGS. 4-7
illustrate such a prior art dual torsion spring
30
. The dual torsion spring
30
has a first end coil
32
and a second end coil
34
separated by intermediate coils
36
. The first end coil
32
has a diameter
38
and the second end coil
34
has a diameter
40
of the same size. Both end coil diameters are reduced in size as compared to a diameter
42
of the intermediate coils
36
.
The dual wound torsion springs shown in
FIGS. 4-7
have been produced utilizing what may be referred to as single-wound technology. Each strand is formed into a coil and then, through post-wind operation, the strands are merged into a dual torsion spring. Heretofore, known manufacturing techniques required each end coil to be of equal diameters. This had certain disadvantages, particularly relevant to shafts of throttles, wherein the shafts had to be over built (or over molded) at one end to accommodate the diameter of an end coil. With reference to
FIGS. 1 and 2
, this would generally require shaft
13
to be over built near lever
12
.
Embodiments of the present invention overcome these and other problems.
SUMMARY OF THE INVENTION
The present invention relates to multiple torsion springs. It more particularly relates to dual torsion springs having dissimilar reduced end coils.
A multiple torsion spring assembly according to the present invention may be provided with a coiled helical dual torsion spring. The spring has first and second end coils, and a plurality of intermediate coils between the first and second end coils. The first end coil inner diameter is less than the inner diameter of the intermediate coils. The second end coil inner diameter is less than the inner diameter of the first end coil.
The multiple torsion spring assembly may be manufactured by supplying at least two strands simultaneously to deflection structure of a type commonly known in the art and deflecting the two strands. The two strands are deflected into a plurality of coils including the first and second end coils and the intermediate coils. The inner diameter of the first end coil is formed smaller than the inner diameter of the intermediate coils. Likewise the inner diameter of the second coil is formed smaller than the inner diameter of the first end coil.
An inventive deflection structure comprising a coiling point assembly is provided herein. The coiling point assembly generally includes a relatively fixed coiling point and a relatively movable coiling point. Preferably two coiling point components are used for dual torsion springs. Each coiling point includes a guide, e.g a groove, for guiding the wires during the coiling process.
The spring may be used to control a throttle return of a throttle body including a lever supported to rotate about an axis of a shaft, and wherein rotation of the lever effects positioning of a throttle valve. The spring is positioned on the shaft to effect rotation of the lever. This includes positioning a tang of one of the end coils to provide a primary source of throttle control. Another tang of the same end coil is positioned to provide a secondary source of throttle control. Other variations using the spring to effect the valve will be apparent to those of skill in the art.
Accordingly, one object of the present invention is to provide a new and improved torsion spring. The intermediate coils shown in
FIG. 13
comprise a portion where the coils taper, in diameter, to form a fructo-conical shape.
Another object of the present invention is to provide a more robust throttle body at a reduced cost.
Another object of the present invention is to provide a more reliable throttle body. A further object is to provide a means for complying with federal standards and regulations requiring system redundancy of select parts.
Another object is to provide improved means and methods for forming springs.
Other objects and advantages of the present invention will be apparent from the following detailed discussion of exemplary embodiments with reference to the attached drawings and claims.


REFERENCES:
patent: 1087186 (1914-02-01), Scholfield
patent: 2028122 (1936-01-01), Floreth
patent: 2559732 (1951-07-01), Padgett
patent: 2668615 (1954-02-01), Sampatacos
patent: 3030783 (1962-04-01), Schmidt
patent: 3055689 (1962-09-01), Jorgensen
patent: 3166950 (1965-01-01), Pomeranz
patent: 3880414 (1975-04-01), Smith et al.
patent: 3905403 (1975-09-01), Smith et al.
patent: 4582653 (1986-04-01), Blanchard et al.
patent: 4828235 (1989-05-01), Paggeot
patent: 4889327 (1989-12-01), Seyler
patent: 5368283 (1994-11-01), Pavlin
patent: 5464197 (1995-11-01), Ecclesfield
patent: 803966 (1951-04-01), None
patent: 865160 (1940-04-01), None
patent: 365451 (1938-12-01), None

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