Acoustics – Sound-modifying means – Housing or enclosure
Reexamination Certificate
2000-05-31
2002-10-01
Nappi, Robert E. (Department: 2837)
Acoustics
Sound-modifying means
Housing or enclosure
C181S200000, C181S205000
Reexamination Certificate
active
06457549
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a noise-absorbing structure for a cable reel. A cable reel is used in steering equipment for automobiles or in similar equipment, and secures electrical connections between fixed elements and mobile elements through a flat cable. The flat cable is stored in a cable-storing enclosure in a spiraled condition. More particularly, the invention concerns an improvement in the assembly structures of a noise-absorbing material, with which a flat cable is put in contact via a spring force.
2. Description of Background Information
As shown in
FIG. 1
, this type of cable reel has a ring-shaped cable-reel enclosure
3
, including a mobile element
1
which rotates with a steering wheel, and a fixed element
2
which is fixed around an axis linked to the car body. A flat cable
4
is contained in the cable-reel enclosure
3
in a spiraled condition. One end of the flat cable
4
is connected to a conductor element linked to the mobile element
1
, while its other end is connected to a conductor element linked to the fixed element
2
. In the above cable reel
4
, when the steering wheel is rotated clockwise or counterclockwise, the flat cable is either wound or unwound. In this manner, equipment mounted on the steering wheel, e.g. an airbag, and electrical power sources on the side of the car body, are electrically connected.
In the above cable reel, when the flat cable
4
is wound or unwound, the side rims of the helical flat cable rub against the surfaces of cable reel enclosure
3
which are in contact with the corresponding side rim. This rubbing emits unpleasant noises. Further, the vibrations caused by idling or driving a car will make the flat cable
4
move to-and-fro along the axis of steering wheel. The flat cable will then bump against the rubbing surfaces, thereby further creating unpleasant noises.
In order to reduce unpleasant rubbing noises, Japanese Utility Model HEI 6-36040 disclosed a mechanism shown in
FIGS. 2A and 2B
, in which a noise-absorbing smooth sheet
5
, e.g. a tetrafluoroethylene resin sheet, is adhered to a top rubbing surface and a bottom rubbing surface, respectively, or only to the bottom rubbing surface
2
a
, with an adhesive material
6
. As an alternative to direct adhesive adhesion as described above, the noise-absorbing smooth sheet and the rubbing surfaces can be fixed mechanically, as shown in FIG.
3
: the internal face of outer circular wall
2
b
of the fixed element
2
is provided with a protrusion
2
c
; the noise-absorbing smooth sheet
5
is then superposed on a supporting plate
7
; and the entire structure is inserted between the bottom rubbing surface
2
a
and the protrusion
2
c
. Alternatively, as shown in
FIG. 4
for a variant, a supporting plate
7
′ is provided with a hook portion
7
a
′, whereas the bottom rubbing surface
2
a
is provided with a stopper hole
2
d.
The noise absorbing smooth sheet
5
is then superposed on, and adhered to, the variant supporting plate
7
′, and the entire structure is fixed to the bottom rubbing surface
2
a
by inserting the hook portion
7
a
′ into the stopper hole
2
d.
In the structures shown in
FIGS. 3 and 4
, a clearance C is formed between the noise-absorbing smooth sheet
5
and the supporting plate
7
, and also between the internal face of outer circular wall
2
b
of the fixed element
2
and an inner circular wall (not shown in the Figures), respectively. Accordingly, vibrations caused by driving the car bias the noise-absorbing smooth sheet
5
and the supporting plate
7
diametrically, so that the supporting plate
7
comes into contact with the outer circular wall
2
b
and the inner circular wall, and generates unpleasant vibration noises. In particular, when the motor is idled, the unpleasant noises caused by vibration sound fairly loud. Besides, when there are clearances C on the external and internal circular rims of both the noise-absorbing smooth sheet
5
and supporting plate
7
, the noiseabsorbing smooth sheet
5
rotates together with the flat cable which is in contact therewith. The noise-absorbing smooth sheet
5
then tends to jolt also in the circumferential direction of the rotation. Rubbing noises may thus be created.
If the supporting plate
7
is downsized with regard to the noise-absorbing smooth sheet
5
, the latter will come into contact with the circular walls, before the support plate
7
will. The vibration noises caused by the support plate
7
may thus be reduced. However, when manufacturing the ring-shaped sheet, the noise-absorbing smooth sheet
5
and the supporting sheet
7
are integrally formed by stamping. Accordingly, it is difficult to downsize only the supporting plate
7
when manufacturing. If they are made separately and secured together, production will become costlier.
When the noise-absorbing smooth sheet
5
shown in
FIG. 2B
is directly adhered to the rubbing face with an adhesive material
6
, the former does not move, thereby generating no vibration noise. However, the noise-absorbing smooth sheet
5
and the adhesive material
6
must then be preliminarily adhered and layered. Moreover, a process step of adhering the adhesive material
6
to the rubbing face must be added in the operation.
An object of the present invention is therefore to provide a cable reel in which the noise-absorbing smooth sheet is fixed to the rubbing face of the cable reel, without being adhered thereto directly. Further, the noise-absorbing smooth sheet and the supporting plate are formed integrally so that the process steps are reduced. This structure prevents the generation of contact noises, which would otherwise be created when the smooth sheet and the supporting plate abut against the circular walls and base wall.
SUMMARY OF THE INVENTION
To solve the above problem, there is provided a noise-absorbing structure for a cable reel, the cable reel including a cable enclosure having a ring shape with a diametrically larger inner circular face and a diametrically smaller inner circular face. The cable enclosure includes a noise-absorbing material formed of a noise-absorbing smooth sheet and a supporting plate, and the diametrically larger inner circular face is unitarily provided with at least two holding tabs arranged substantially at equal intervals in the circumferential direction, such that the holding tabs immobilize the noise-absorbing material by holding the noise-absorbing smooth sheet.
Suitably, the at least two holding tabs include three or four holding tabs. The diametrically smaller inner circular face may also be provided unitarily with at least two, suitably three or four, holding tabs arranged in the circumferential direction and spaced apart with substantially the same distance therebetween.
In the above structure, the cable enclosure may further include a fixed element, and a mobile element mounted thereon in a freely rotatable way, so as to form a ring-shaped enclosure at least including an outer circular wall, an inner circular wall and a base wall.
In a preferred embodiment, the ring-shaped enclosure with the base wall is provided with a notch having two opposing side faces which extend inwardly from the outer circular wall. The noise-absorbing material is then sized to the same shape as the base wall and is superposed thereon, and the two opposing side faces include holding tabs which immobilize the noise-absorbing material by holding the noise-absorbing smooth sheet.
Preferably still, the base wall of the fixed element is provided with rapping holes corresponding to the holding tabs, and the rapping holes serve as checking holes to check whether or not the noise-absorbing material is mounted in the cable enclosure.
There is also provided a cable reel including a noise-absorbing structure, the cable reel including a cable enclosure having a ring shape with a diametrically larger inner circular face and a diametrically smaller inner circular face, wherein the cable enclosure includes a noise-absorbing material formed of a n
Greenblum & Bernstein P.L.C.
Lockett Kim
Nappi Robert E.
Sumitomo Wiring Systems Ltd.
LandOfFree
Noise-absorbing structure for a cable reel does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Noise-absorbing structure for a cable reel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Noise-absorbing structure for a cable reel will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2987881