Land vehicles – Wheeled – Running gear
Reexamination Certificate
2002-10-22
2004-10-05
Ilan, Ruth (Department: 3616)
Land vehicles
Wheeled
Running gear
C280S775000
Reexamination Certificate
active
06799779
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tilt type steering column for a motor vehicle. Especially, the present invention relates to a shock-absorbing mechanism of the tilt type steering column.
2. Description of the Related Art
A tilt type steering column allows a steering wheel to move upward and downward so as to secure a proper driving position (attitude) of a seat occupant. The tilt type steering column can have the following construction:
A distance bracket is fixed to the tilt type steering column. A tilt bolt is inserted into the distance bracket. A support bracket otherwise referred to as “upper clamp” or “upper bracket” is fixed to a vehicular body. The tilt bolt has a first end and a second end which engage respectively with a first elongate hole {formed upward and downward in a first side wall of the support bracket} and a second elongate hole {formed upward and downward in a second side wall of the support bracket}. Thereby, the tilt bolt can slidably move upward and upward, or can be fixed in a predetermined position for tilt adjustment.
For securing the seat occupant's safety in an accident (collision) of the motor vehicle, the shock-absorbing mechanism of the tilt type steering column can have the following functions:
The tilt type steering column can absorb a shock energy which may be caused in a primary collision (namely, a collision of the vehicular body with another vehicular body, an obstacle and the like), and a secondary collision (namely, a collision of the seat occupant with the tilt type steering wheel) attributable to the primary collision, thereby reducing as much as possible or absorbing a load applied to the seat occupant.
The shock-absorbing tilt type steering column has various constructions. As is seen in
FIG. 7
, Japanese Patent Unexamined Publication No. Heisei 8 (1996)-295251 (=JP8295251) discloses a shock-absorbing tilt type steering column. A steering shaft
19
is rotatably supported by a bearing
20
of a column jacket
21
. A support bracket
22
is formed with a vehicular body mounting section
23
. The column jacket
21
has a rear end side which is secured to the vehicular body by way of the vehicular body mounting section
23
. A distance bracket
24
coupling with the column jacket
21
is formed with an engagement groove
25
opening rearward.
The tilt bolt
26
engages with the engagement groove
25
in such a manner that the tilt bolt
26
can disengage from the engagement groove
25
when an excessive load {greater than an allowable load (upper limit)} is applied to the distance bracket
24
. The support bracket
22
has a side wall
27
which is formed with an elongate hole
28
. The tilt bolt
26
engages with the elongate hole
28
, thus allowing the distance bracket
24
to slide upward and downward. Moreover, operating a tilt lever
29
allows the support bracket
22
to tighten and/or relax the distance bracket
24
.
Herein, the shock-absorbing mechanism has the following construction:
An energy absorber
30
has a rear end (right in
FIG. 7
) formed with a fixture end
31
which couples with the distance bracket
24
through a welding and the like. The fixture end
31
is shaped substantially into a key. The rear end of the energy absorber
30
also has a bent section
32
which is so shaped substantially into an English alphabet “U” as to wind about the tilt bolt
26
. The energy absorber
30
made of metal is a strap having a predetermined length, and extends forward (leftward in
FIG. 7
) along the column jacket
21
.
In the secondary collision, the above shock-absorbing mechanism can bring about the following effects:
The excessive load {greater than the allowable load (upper limit)} applied axially from the steering shaft
19
to the column jacket
21
by way of the bearing
20
causes the distance bracket
24
to disengage from the tilt bolt
26
. Thereby, the tilt bolt
26
which keeps engagement with the support bracket
22
causes plastic deformation to the energy absorber
30
, thus absorbing the shock.
With the shock-absorbing tilt type steering column according to the Japanese Patent Unexamined Publication No. Heisei 8 (1996)-295251 (=JP8295251), however, the side wall
27
of the support bracket
22
is in need of a certain dimension for allowing the elongate hole
28
(opening in the side wall
27
) to secure a predetermined space for tilting the steering column. Thereby, the side wall
27
dangling downward from the vehicular body mounting section
23
of the support bracket
22
becomes greater than the elongate hole
28
in overall dimension. As a result, a lower section of the support bracket
22
may touch the seat occupant's knee or thigh, thus discomforting the seat occupant.
Moreover, the energy absorber
30
is partly exposed below the support bracket
22
. The energy absorber
30
plastically deformed in the secondary collision may also touch the seat occupant's knee or thigh. For preventing the energy absorber
30
from touching the seat occupant's knee or thigh, a cover and the like is supposed to add to the lowermost position of the support bracket
22
, resulting in further diminished space above the seat occupant's knee or thigh.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a shock-absorbing tilt type steering column for a motor vehicle.
It is another object of the present invention to allow the shock-absorbing tilt type steering column to have safe and sufficient space above the seat occupant's knee or thigh.
According to a first aspect of the present invention, there is provided a shock-absorbing tilt type steering column, comprising:
1) a column jacket having a lowermost section, a space being defined above the column jacket;
2) a coupler;
3) an upper clamp including a pair of a first side wall and a second side wall formed respectively with a first hole and a second hole for tilting the shock-absorbing tilt type steering column, the coupler being inserted into the first hole and the second hole, the space defined above the column jacket being defined in the upper clamp, each of the pair of the first side wall and the second side wall having such a height that a lower end thereof is disposed substantially on a level with or higher than the lowermost section of the column jacket when the coupler is disposed in an uppermost position of each of the first hole and the second hole;
4) a distance bracket sandwiched between the first side wall and the second side wall of the upper clamp in such a manner as to move upward and downward, the distance bracket coupling with the column jacket, the distance bracket being adapted to engage with the coupler in such a manner as to be disengageable from the coupler in a forward direction of a vehicle when a load greater than an upper limit is applied to the distance bracket axially in a direction along the column jacket, the distance bracket being disposed in the space with the lower end of each of the first side wall and the second side wall disposed substantially on the level with or higher than the lowermost section of the column jacket; and
5) an energy absorber interposed between the distance bracket and the coupler.
According to a second aspect of the present invention, there is provided a shock-absorbing steering system, comprising:
1) a column jacket shaped substantially into a cylinder having a lowermost section, the column jacket defining a center section and a front end side, a space being defined above the column jacket;
2) a coupler;
3) an upper clamp disposed in the center section of the column jacket, the upper clamp including a pair of a first side wall and a second side wall formed respectively with a first hole and a second hole, the coupler being inserted into the first hole and the second hole, the space defined above the column jacket being defined in the upper clamp, each of the pair of the first side wall and the second side wall having such a height that a lower en
Foley & Lardner LLP
Fuji Kiko Co. Ltd.
Ilan Ruth
LandOfFree
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