Chairs and seats – Headrest
Reexamination Certificate
2002-11-08
2004-12-21
Barfield, Anthony D. (Department: 3636)
Chairs and seats
Headrest
C297S463100, C297S463200
Reexamination Certificate
active
06832816
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a metallic cylindrical member and a metallic bracket. Particularly, the invention is concerned with a metallic cylindrical member and a metallic bracket, which are formed by joining a pair of sides of a metallic plate.
2. Description of the Prior Art
According to the prior art, as shown in
FIG. 37
, a generally square pipe-shaped metallic frame
1
a
with an axis oriented in a nearly horizontal direction is disposed at an upper position in the interior of a seat back
1
of a first seat mounted on an automobile, and generally square pipe-shaped metallic brackets
1
b
and
1
c
having axes oriented nearly vertically are attached to the metallic frame
1
a.
Generally cylindrical headrest supports
3
and
4
are inserted into the metallic brackets
1
b
and
1
c
, the headrest supports
3
and
4
supporting headrest stays
2
a
and
2
b
which are projected substantially in a vertically downward direction from the headrest
2
.
As shown in
FIG. 38
, the metallic brackets
1
b
and
1
c
are each formed in the shape of a square pipe by bending a metallic plate so that left and right sides of the metallic plate are opposed to each other and by subsequently joining the opposed sides. The portions to be joined of the metallic brackets
1
b
and
1
c
are designed to take spring-back into account and therefore a clearance of a predetermined width is formed between both sides of the metallic plate.
The joined portions are brought into a substantially closely contacted state with one flat wall surface of the metallic frame
1
a
and in this state welding is applied to between the bent portions of the metallic brackets
1
b
,
1
c
and the wall surface of the metallic frame
1
a
abutted against the bent portions, whereby the metallic brackets
1
b
and
1
c
are fixed to the metallic frame
1
a.
In the above conventional metallic cylindrical member, since the metallic brackets
1
b
and
1
c
are welded to the metallic frame
1
a
, welded portions
5
shown in
FIG. 38
shrink on cooling. With this shrinkage of the welded portions
5
, the bent portions of the metallic brackets
1
b
and
1
c
abutted against the metallic frame
1
a
are pulled away from each other. Consequently, the sides of the metallic brackets
1
b
and
1
c
move away from each other, resulting in a wider width than the foregoing predetermined width. Thus, there has been a problem that an inside diameter of the metallic cylindrical member is changed by welding despite the inside diameter being designed to a value which permits the headrest supports to be supported without clearance in a state before welding.
SUMMARY OF THE INVENTION
Accordingly, the present invention aims to solve said problems and to provide a metallic cylindrical member and a metallic bracket both able to suppress a change in inside diameter which is caused by an external force applied on cooling of a welded portion.
In one aspect, the invention is constructed such that concave and convex shapes adapted to engage each other in an anti-dislodgment manner are formed at a pair of sides of a metallic plate, then both sides are confronted with each other and the concave and convex shapes are put in engagement with each other to join both sides.
In this construction, when a pair of sides of a metallic plate are opposed to each other and concave and convex shapes formed at both sides are engaged with each other to join both sides, both sides are engaged with each other in an anti-dislodgment manner and are thereby joined strongly.
According to this construction, when the metallic cylindrical member thus formed is welded to another metallic member, even if the welded portion shrinks on cooling and an external force is applied in a direction in which are joined sides are pulled apart from each other or in a direction in which the joined sides are abutted against each other, displacement of both sides joined strongly is prevented and hence a change in inside diameter of the metallic cylindrical member is prevented.
Thus, it is possible to provide a metallic cylindrical member able to prevent a change in its inside diameter which is caused by an external force applied on cooling of the welded portion.
In another aspect, the invention is constructed such that the concave and convex shapes formed on both sides of the metallic plate may by formed so as to have approximately equal shortest distances in the seam direction.
More specifically, the concave and convex shapes are formed so that a shortest distance in the seam direction of a concave or convex shape formed on one side is approximately equal to a shortest distance in the seam direction of a concave or convex shape formed on the other side.
That is, when plural projections are formed on each side and opposed projections are engaged with each other, the sum of shortest distances in the seam direction of the projections formed on one side and the sum of shortest distances in the seam direction of the projections formed on the other side become almost equal to each other. This enables to enhance the strength of the joined portion.
Note that where such projections as mentioned above are formed, the “shortest distance” on each side indicates the sum of minimum widths of the projections in the seam direction. If the projections are constricted at their base portions, the shortest distance in question indicates the sum of widths of the base portions in the seam direction.
The concave and convex shapes may be formed so that the shortest distance throughout the whole of one side and the shortest distance throughout the whole of the other side are almost equal to each other. Alternatively, the concave and convex shapes may be formed so that the shortest distance in part of one side and the shortest distance in part of the other side are almost equal to each other.
In another aspect, the invention is constructed such that as an example of a method for joining both sides together, both sides may be crushed in the thickness direction at portions including mutually opposed concave and convex shapes in an engaged state of the concave and convex shapes formed on both sides.
According to this construction, when the concave and convex shapes formed on both sides are engaged with each other, both sides are crushed in the thickness direction at portions including mutually opposed concave and convex shapes and are joined together.
As a result, metal is shifted from the crushed portion toward the concave/convex boundary, whereby the adhesion at the boundary is enhanced and so is the strength of the joined portion.
In another aspect, the invention is constructed such that as an example of the crushing, both sides may be crushed stripewise into indentations at portions including the concave and convex shapes.
In this case, when stripe-shaped indentations are formed by crushing so as to include the concave and convex shapes, metal is dispersed from the indentations toward the concave/convex boundary. This enables to easily enhance the strength of the joined portion.
In another aspect, the invention is constructed such that as an example of forming such indentations, the indentations may be formed by crushing both sides stripewise at portions including the concave and convex portions while allowing the stripes to escape obliquely relative to the concave/convex boundary.
According to this construction wherein indentations are formed stripewise obliquely relative to the boundary, metal is dispersed widely in the seam direction. Thus, this method is useful for dispersing metal widely around the boundary and thereby realizing a strong joint of both sides.
Thus forming indentations while allowing escape obliquely relative to the concave/convex boundary is advantageous in that metal can be dispersed widely in the seam direction. But from the standpoint that it suffices for the indentations to be formed by crushing both sides stripewise at portions including the concave and convex shapes, they also may be formed in a direction nearly perpendic
Barfield Anthony D.
Nihon Technica Co., Ltd.
Sughrue & Mion, PLLC
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