Information
-
Patent Grant
-
6241316
-
Patent Number
6,241,316
-
Date Filed
Tuesday, November 17, 199825 years ago
-
Date Issued
Tuesday, June 5, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 248 161
- 248 1621
- 248 404
- 248 157
- 248 631
- 297 34419
- 297 34418
- 297 DIG 3
- 188 313
- 188 314
- 188 316
- 267 641
- 267 6426
- 267 124
- 277 442
- 277 540
-
International Classifications
-
Abstract
Disclosed is a gas cylinder type height-adjusting apparatus of a swivel chair which has a simple structure and thereby can be manufactured at a low cost. In the apparatus, an actuating pin opens an orifice so that working fluid can flow from the first chamber through the second chamber into the third chamber when the actuating pin is pressed down, while the actuating pin blocks up the orifice when the actuating pin is not pressed down. The orifice is formed in an actuating pin socket manufactured by coating synthetic resin after an integral single forming of a single material. The first chamber is defined by an alternating piston which is manufactured by coating synthetic resin after an integral single forming of a single material. The shaft bearing member has a shape of a single annular ring whose upper and lower surfaces are curved surfaces curved with a predetermined curvature or tapered surfaces tapered at a predetermined angle.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for adjusting the height of a swivel chair, and more particularly to a gas cylinder type height-adjusting apparatus of a swivel chair which has a simple structure and thereby can be manufactured at a low cost.
2. Description of Prior Art
In general, a swivel chair has a part named as a spindle which performs functions of not only supporting the weight of a person seated thereon but also adjusting the height of the chair according to the physique of the person.
The spindle is an important part of a swivel chair in adjusting the height of the chair and can be classified as two types according to the height-adjusting manner, including a screw-adjusting type using a screw spindle and a gas cylinder type in which usually a nitrogen gas functions as a working fluid.
FIG. 1
is a sectional view of a conventional height-adjusting apparatus of a swivel chair having a gas cylinder type spindle for showing the construction thereof. In
FIG. 1
, reference numeral
10
designates a spindle having a shape of a cylinder. The spindle
10
is inserted in an outer tube
20
having a larger diameter, and a piston rod
30
is inserted into the spindle
10
through the bottom of the spindle
10
.
A top stopper
16
is fixed to the top of the spindle
10
, and an actuating protuberance
14
is slidably fitted in the top stopper
16
. The actuating protuberance
14
is connected to a height-adjusting lever (not shown) for adjusting the height of the swivel chair. A pushing rod
18
integrally formed under the actuating protuberance
14
is in contact with an actuating pin
19
. The actuating pin
19
is slidably fitted in an actuating pin socket
40
so as to slide up and down therein. The actuating pin socket
40
, whose more detailed construction will be given later, is fixed in the spindle
10
with providing gas-tight therein.
The outer tube
20
of a cylindrical shape has a spindle support
50
fixed to a lower part of the outer tube
20
. The piston rod
30
is fixed to the spindle support
50
. The spindle
10
has a spindle neck
12
at an upper part thereof which is tapered so as to be inserted in a seat (not shown) of the chair.
The spindle
10
surrounds a cylinder
44
which has a smaller diameter than the spindle
10
. The spindle
10
has a buffer disposed in the spindle
10
for providing a comfortable feeling for the person seated thereon. A thrust bearing
60
is arranged on the spindle support
50
so as to ensure a smooth swivel of the chair with bearing the weight from above. The reference numeral
62
designates a cushion such as a rubber which comes into contact with the bottom of the spindle
10
. The cushion
62
buffers the impact on the bottom of the spindle
10
when the spindle
10
is lowered down to its lowermost position.
The bottom of the piston rod
30
is detachably installed on the spindle support
50
by means of a clip
70
. In
FIG. 1
, the reference numeral
52
designates a spindle holding member which is disposed between the spindle
10
and the outer tube
20
so as to hold the spindle
10
in such a manner that the spindle
10
can slide therethrough into and out of the outer tube
20
.
FIG. 2
is an enlarged sectional view of the actuating pin socket
40
disposed in the spindle
10
of FIG.
1
. As shown, the actuating pin socket
40
, shaped roughly like a cylinder, has an actuating pin hole
41
formed through the center of the actuating pin socket
40
in which the actuating pin
19
is fitted. The actuating pin socket
40
also has a plurality of socket O-ring grooves
43
formed around the outer circumferential surface of the actuating pin socket
40
in each of which a socket O-ring
45
is fitted.
The inner center portion of the actuating pin socket
40
forms a central space
46
for passing gas therethrough in which at least two socket O-rings
45
and an inner holder
47
are arranged. The socket O-rings
45
maintain gas-tight in the central space
46
, and the inner holder
47
holds the socket O-ring
45
of the inner side and helps smooth sliding of the actuating pin
19
. The actuating pin socket
40
has an orifice
42
formed at one side of the actuating pin socket
40
. The orifice
42
is connected to an outer space of the cylinder
44
. The inner holder
47
has a connecting pore
47
a
formed at one side of the inner holder
47
and connected to the orifice
42
.
Referring to
FIG. 2
, the actuating pin
19
has a small-diameter portion
19
a
formed at a middle portion of the actuating pin
19
. The small-diameter portion
19
a
has a diameter smaller than that of the remaining portion of the actuating pin
19
. When the actuating pin
19
is lowered down, the small-diameter portion
19
a
makes a small gap between the actuating pin
19
and the actuating pin socket
40
, so that gas filled in a first chamber A can flow into the central space
46
of the actuating pin socket
40
and then into a second chamber B through the orifice
42
. In
FIG. 2
, reference numeral
13
designates a holding washer provided in the actuating pin socket
40
to hold the socket O-rings
45
in the actuating pin socket
40
. Nitrogen gas and oil are filled in the first chamber A, as working gas and fluid.
FIG. 3
is an enlarged sectional view for showing the construction of a piston
80
installed at the top of the piston rod
30
in detail, and
FIG. 4
is an enlarged sectional view for showing the operation of the piston
80
.
The piston rod
30
has a piston rod head
87
which prevents the piston rod
30
from being separated from the piston
80
. The piston
80
has a plurality of inner and outer O-ring grooves in each of which a piston O-ring
82
is fitted to make gas-tight. The piston
80
has various parts which enable the piston
80
to smoothly and closely slide in the cylinder
44
and prevent the piston
80
from coming out of the spindle
10
. The bottom of the spindle
10
is bent inward so as to prevent the piston
80
from escaping.
The spindle
10
houses a flange
83
disposed in the bottom thereof and a sealing member
84
disposed on the flange
83
for maintaining gas-tight in the cylinder
44
. Between the piston
80
and the sealing member
84
, an annulus
85
and a cylinder holder
86
are arranged in order from above. The annulus
85
surrounds a spring ring
88
for fixing the piston
80
to the piston rod
30
, and the cylinder holder
86
supports the bottom of the cylinder
44
.
Referring to
FIG. 4
, the cylinder holder
86
has a gas-passing hole
86
a
formed through an outer portion of the cylinder holder
86
. The gas-passing hole
86
a
provides a path from the second chamber B to the third chamber C. Therefore, the gas-passing hole
86
a
enables the gas to flow from the first chamber A through the second chamber B into the third chamber C. Arrows in
FIG. 4
shows the gas flow from the second chamber B to the third chamber C.
FIGS. 5A and 5B
are respectively an exploded and an assembled elevations of the actuating pin
19
employed in the conventional gas cylinder type height-adjusting apparatus shown in FIG.
1
. The actuating pin
19
has a small-diameter portion
19
a
and two large-diameter portions
19
b
. The small-diameter portion
19
a
is integrally connected to each of the large-diameter portions
19
b
through a sloping portion
19
c
. The lower large-diameter portion
19
b
has an actuating pin neck
19
d
protruding downward from the bottom of the large-diameter portion
19
b.
Referring to
FIG. 5B
, the actuating pin neck
19
d
is inserted in a fixing washer
17
and then a holding head
19
e
is assembled at the lower end of the actuating pin neck
19
d
, so as to fix the fixing washer
17
thereto. The fixing washer
17
comes apart from the holding washer
13
when an external force as shown by an arrow in
FIG. 2
is applied, while the fixing washer
17
comes into contact with the holding washer
13
when the pressure of the gas filled in the first chamber A is applied to the fixing washer
17
. Reference numeral
17
a
designates a fixing washer hole formed at the center of the fixing washer
17
so as to receive the actuating pin neck
19
d.
FIG. 6
is an enlarged sectional view of the actuating pin
19
and the actuating pin socket
40
for showing the operation of the actuating pin
19
in the actuating pin socket
40
. When the actuating protuberance
14
shown in
FIG. 1
is pressed by means of the height-adjusting lever (not shown), the pushing rod
18
formed integrally with the actuating protuberance
14
pushes down the actuating pin
19
, which state is shown in FIG.
6
.
When the actuating pin
19
is pushed down, the small-diameter portion
19
a
of the actuating pin
19
is lowered down so as to make the first chamber A and the central space
46
intercommunicate with each other. In this case, the gas in the first chamber A flows through the central space
46
, the connecting pore
47
a
and the orifice
42
into the second chamber B. Moreover, the gas flown into the second chamber B from the first chamber A continues to flow to the third chamber C through the gas-passing hole
86
a
shown in detail in FIG.
4
.
FIG. 7
is a sectional view of the conventional height-adjusting apparatus of
FIG. 1
for showing the descending operation of the gas cylinder type spindle
10
. As the gas in the first chamber A decreases while the gas in the third chamber C increases, the piston
80
is pushed up due to the change of the pressure difference between the two chambers, as shown in FIG.
7
. In other words, the pressure of the gas in the third chamber C, which is larger than that in the first chamber A, pushes the piston
80
up and the spindle
10
down, to thereby lower the spindle
10
down because the piston
80
is fixed to the spindle support
50
of the outer tube
20
by means of the piston rod
30
.
The above described conventional height-adjusting apparatus of the gas cylinder type has following problems.
First, the actuating pin socket
40
is made of metal, usually of aluminum because it can be easily treated. However, aluminum is very expensive and apt to be damaged in the course of being treated. Therefore, there is a high possibility that the manufactured goods of the actuating pin socket
40
has defects such as scratches on its surface, despite the fact that the actuating pin socket
40
must have a surface of a high accuracy for ensuring the gas-tight characteristic.
Second, the complicated construction of the actuating pin socket
40
increases the manufacturing cost and disturbs its mass production. Third, the socket O-ring
45
and the inner holder
47
assembled with the actuating pin socket
40
increase manufacturing steps and labor power. Fourth, even when all parts of the actuating pin socket
40
excepting the socket O-rings
45
are manufactured by injection molding, there remains a molding line between the upper mold and the lower mold on the actuating pin socket
40
, which requires a further finishing step in manufacturing the actuating pin socket
40
and lowers the surface accuracy of the manufactured actuating pin socket
40
.
Fifth, the conventional actuating pin
19
must have a high accuracy of its size for ensuring the gas tight characteristic in spite of being made from relatively hard material. However, the actuating pin neck
19
d
for fixing the fixing washer
17
makes the construction of the actuating pin
19
more complicated to thereby require relatively hard labor in its manufacturing, disturb its mass production, and increase its manufacturing cost. Further, the assembling of the holding head
19
e
with the actuating pin neck
19
d
can have an impact on the remaining portions of the actuating pin
19
, so as to make distortion in the actuating pin
19
, which is not preferable for a part requiring a high accuracy.
Sixth, the piston
80
requires a further manufacturing step of assembling the piston O-ring
82
on the inner and outer surfaces of the piston
80
, which increases the required labor and expense. Seventh, it is very difficult to assemble the piston rod
30
with the outer tube
20
, and the piston rod
30
is apt to be separated from the outer tube
20
even after the assembling.
FIGS. 8
to
10
show another conventional height-adjusting apparatus of a swivel chair having a screw type spindle.
FIG. 8
is an exploded perspective view of the conventional screw type height-adjusting apparatus of a swivel chair, and
FIGS. 9 and 10
are perspective views of two types of conventional shaft bearing members employed in the conventional screw type height-adjusting apparatus of FIG.
8
.
In
FIG. 8
, reference numerals
100
and
200
respectively designate an outer tube and a spindle installed in the outer tube. The outer tube
100
is cylindrical, and the spindle
200
has an inner tube
240
of a cylindrical shape and a spindle neck
220
connected integrally to the inner tube
240
. The inner tube
240
has a plurality of dents
242
for holding a support ring
320
. The spindle neck
220
is tapered so as to be inserted in a seat (not shown) of the chair. The spindle
200
houses an elastic buffer
300
for ensuring comfort of the seated person, a shaft bearing member
500
for ensuring a smooth swivel of the spindle, a rubber ring
600
for maintaining the height of the chair, and a screw nut
700
and a clutch
800
for adjusting the height of the chair.
Reference numerals
120
,
320
, and
502
respectively designate a spindle guide disposed between the outer tube
100
and the spindle
200
to support them, a support ring disposed between the stopping dents
242
and the elastic buffer
300
, and balls fitted in the shaft bearing member
500
. Reference numeral
590
designates bearing supports disposed respectively on and beneath the shaft bearing member
500
to protect it.
The spindle
200
also houses a screw shaft
900
passing through the elastic buffer
300
, the shaft bearing member
500
, the rubber ring
600
, the screw nut
700
, and the clutch
800
. A screw shaft disc
910
is installed at the bottom of the screw shaft
900
. The screw shaft disc
910
has a circular screw shaft hole
912
for preventing the screw shaft
900
from idly rotating. A nut support
920
limits descending of the screw nut
700
.
The clutch
800
is fixed to the bottom of the spindle
200
. The screw nut
700
has a sloping groove
720
and a plurality of teeth grooves
780
respectively formed at the upper and the lower surfaces thereof. The clutch
800
has a plurality of teeth
820
formed on the upper surface thereof. The sloping groove
720
receives the rubber ring
600
, and the teeth
820
are engaged with the teeth grooves
780
.
Referring to
FIG. 9
, the shaft bearing member
500
contains a plurality of the balls
502
. Therefore, when a weight is loaded, the bearing supports
590
disposed on and beneath the shaft bearing member
500
are in contact with the balls
502
, so as to reduce the sliding resistance, thereby ensuring a smooth swivel of the chair. In
FIG. 9
, reference numeral
504
designates a hole for passing the screw shaft
900
therethrough.
However, the above shaft bearing member
500
has at least four balls
502
for ensuring the smooth swivel of the spindle
200
. This structure causes a problem; that is, the metal balls
502
inserted in the shaft bearing member
500
of hard synthetic resin can cause a structural problem. Further, this metal-ball-containing shaft bearing member
500
has many problems such as complicated manufacturing process, problematic durability, and expensive manufacturing cost.
Referring to
FIG. 10
, the shaft bearing member
500
has an outer cylindrical wall
510
and an inner cylindrical wall
520
integrally connected to each other through a plurality of bridges
530
. The bridges
530
have a smaller vertical width than the outer cylindrical wall
510
and the inner cylindrical wall
520
. The bridges
530
provide a grease-filling gap
540
between the outer cylindrical wall
510
and the inner cylindrical wall
520
and each of the bridges
530
has a grease-flowing groove
550
, so that grease can be filled and freely flow in the grease-filling gap
540
through the grease-flowing grooves
550
. The shaft bearing member
500
can be made from material selected between hard synthetic resin and metal. Reference numeral
560
designates a hole formed at the center thereof so as to pass the screw shaft
900
therethrough.
In this type of the shaft bearing member
500
shown in
FIG. 10
, grease filled in the grease-filling gap
540
protects frictional parts to thereby enhance the durability of the shaft bearing member
500
. However, the shaft bearing member
500
has a very complicated structure, because the outer cylindrical wall
510
, the bridges
530
, and the inner cylindrical wall
520
are integrally connected one another and the shaft bearing member
500
has the grease-filling gap
540
and the grease-flowing groove
550
. Therefore, it is difficult to manufacture the metal mold of the shaft bearing member
500
, and the manufacturing cost of the shaft bearing member
500
is increased.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the above described problems of the prior arts, and accordingly it is an object of the present invention to provide an apparatus for adjusting the height of a swivel chair, which has a simple structure and remarkably reduces its manufacturing steps and manufacturing cost.
To achieve the above object, the present invention provides an apparatus for adjusting a height of a swivel chair, said apparatus comprising:
an outer tube rotatably fitted in a seat of the swivel chair;
a spindle slidably inserted in the outer tube, the spindle containing a cylinder fixed in the spindle by means of a cylinder holder disposed at a lower portion of the spindle;
a piston rod fixedly contained in the outer tube and slidably inserted in the spindle through a bottom of the spindle;
an actuating pin socket fixed at a top of the cylinder, the actuating pin socket having a socket body and a socket coating coated on the socket body, the socket body having an actuating pin hole and an orifice formed in the socket body, the actuating pin socket being manufactured by an integral single forming;
an actuating pin slidably fitted in the actuating pin hole; and
a piston fixed at an upper portion of the piston rod and slidably fitted in the cylinder, the actuating pin socket and the piston defining a first chamber above the cylinder in the cylinder, the spindle and the cylinder defining a second chamber between the spindle and the cylinder, the piston and the cylinder defining a third chamber under the piston in the cylinder, the orifice of the socket body being connected to the second chamber, the second chamber and the third chamber communicating through a gas-passing hole formed through an outer portion of the cylinder holder, the first, the second, and the third chambers containing working fluid,
wherein, the actuating pin opens the orifice to communicate the first chamber with the second chamber so that working fluid can flow from the first chamber through the second chamber into the third chamber when the actuating pin is pressed down, while the actuating pin blocks up the orifice when the actuating pin is not pressed down.
It is preferred that the socket body is made from metal and the socket coating is made from elastic material. The socket body has an annular reinforcement protruding outward from a middle portion of the socket body, the orifice being formed through the annular reinforcement. The socket coating has a plurality of annular socket protuberances protruding from an inner and an surfaces of the socket coating, the annular socket protuberances functioning like O-rings.
The piston has a cylindrical piston body and a piston coating coated on the piston body, the piston being manufactured by an integral single forming. The actuating pin has a small-diameter portion, two large-diameter portions, and two sloping portions formed integrally with each other, each of the sloping portions being disposed between the small-diameter portion and each of the large-diameter portions.
More preferably, the apparatus further has a shaft bearing member provided at a bottom of the piston rod in the outer tube to bear a weight transferred through the piston rod, wherein the shaft bearing member has a shape of a single annular ring whose upper and lower surfaces are curved surfaces curved with a predetermined curvature or tapered surfaces tapered at a predetermined angle.
The apparatus also has a retainer washer having a plurality of retaining keys protruding upward or downward from an inner circumference of the retainer washer, the retaining keys being engaged in a plurality of piston rod grooves formed on a cylindrical surface of a lower end of the piston rod, so as to firmly fix the piston rod.
When the actuating pin is pushed down, the small-diameter portion of the actuating pin is lowered down so as to make the first chamber and the central space intercommunicate with each other. In this case, the gas in the first chamber flows through the central space and the orifice into the second chamber. Moreover, the gas flown into the second chamber from the first chamber continues to flow to the third chamber.
As the gas in the first chamber decreases while the gas in the third chamber increases, the piston is pushed up. In this case, the pressure of the gas in the third chamber, which is larger than that in the first chamber, pushes the piston up and the spindle down, to thereby lower the spindle down because the piston is fixed to the spindle support of the outer tube by means of the piston rod.
BRIEF DESCRIPTION OF THE DRAWINGS
The above object, and other features and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings, in which:
FIG. 1
is a sectional view of a conventional height-adjusting apparatus of a swivel chair having a gas cylinder type spindle;
FIG. 2
is an enlarged sectional view of an actuating pin socket disposed in the spindle of
FIG. 1
;
FIG. 3
is an enlarged sectional view of a piston disposed in the spindle of
FIG. 1
;
FIG. 4
is an enlarged sectional view of the piston shown in
FIG. 3
in its operated state;
FIGS. 5A and 5B
are an exploded and an assembled sectional views of an actuating pin disposed in the spindle of
FIG. 1
;
FIG. 6
is an enlarged sectional view for showing the actuating pin shown in
FIGS. 5A and 5B
;
FIG. 7
is a sectional view of the conventional height-adjusting apparatus of
FIG. 1
for showing the descending operation of the gas cylinder type spindle;
FIG. 8
is an exploded perspective view of a conventional screw type height-adjusting apparatus of a swivel chair;
FIGS. 9 and 10
are perspective views of two types of conventional shaft bearing members employed in the conventional screw type height-adjusting apparatus of
FIG. 8
;
FIGS. 11A
,
11
B, and
11
C are respectively a partly cut-out perspective view, a perspective view, and a sectional view of an actuating pin socket employed in a height-adjusting apparatus of a swivel chair according to the present invention, and
FIG. 11D
is a sectional view of a socket body of the actuating pin socket shown in
FIGS. 11A
, ,
11
B, and
11
C;
FIGS. 12A
,
12
B, and
12
C are respectively a partly cut-out perspective view, a perspective view, and a sectional view of a piston employed in a height-adjusting apparatus of a swivel chair according to the present invention;
FIG. 13
is a partly cut out enlarged view of a spindle containing the actuating pin socket shown in
FIGS. 11A
,
11
B,
11
C and
11
D;
FIG. 14
is a partly cut out enlarged view of a spindle containing the piston shown in
FIGS. 12A
,
12
B and
12
C;
FIG. 15
is an enlarged side elevation of an actuating pin fitted in the actuating pin socket in the spindle shown in
FIG. 13
;
FIGS. 16 and 17
are a partly cut out enlarged view and a sectional view of shaft bearing members according to embodiments of the present invention, which are employed in a height-adjusting apparatus of a swivel chair as shown in
FIG. 21
;
FIGS. 18 and 19
are a sectional view and a plan view of other shaft bearing members according to other embodiments of the present invention, further to the shaft bearing members of
FIGS. 16 and 17
;
FIGS. 20A
,
20
B, and
20
C are plan views of retainer washers according to several embodiments of the present invention, which are employed in the height-adjusting apparatus of a swivel chair as shown in
FIG. 21
, and
FIG. 20D
is a side elevation of the retainer washers shown in
FIGS. 20A
,
20
B, and
20
C; and
FIG. 21
is a partly cut-out enlarged view of an outer tube according to an embodiment of the present invention, which contains the retainer washer shown in FIG.
20
D.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, several preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, especially to
FIG. 11A
to FIG.
21
.
Referring to
FIGS. 13
,
14
and
21
, similarly to the conventional height-adjusting apparatus shown in
FIG. 1
, a height-adjusting apparatus of a swivel chair according to the present invention includes a spindle
110
of a cylindrical shape, an outer tube
120
having a larger diameter to receive the spindle
110
therein, and a piston rod
130
inserted into the spindle
110
through the bottom of the spindle
110
.
Referring to
FIG. 13
, a top stopper
116
is fixed to the top of the spindle
110
, and an actuating protuberance
114
is slidably fitted in the top stopper
116
. The actuating protuberance
114
is connected to a height-adjusting lever (not shown) for adjusting the height of the swivel chair. A pushing rod
118
integrally formed under the actuating protuberance
114
is in contact with an actuating pin
119
. The actuating pin
119
is slidably fitted in an actuating pin socket
140
so as to slide up and down therein. The actuating pin socket
140
, whose more detailed construction will be given later, is fixed in the spindle
110
with providing gas-tight therein.
Referring to
FIG. 21
, the outer tube
120
has a spindle support
150
fixed to a lower part of the outer tube
120
. The piston rod
130
is fixed to the spindle support
150
. The spindle
110
has a spindle neck
112
at an upper part thereof which is tapered so as to be inserted in a seat (not shown) of the chair. The bottom of the piston rod
130
is detachably installed on the spindle support
150
by means of a clip
170
. The reference numeral
162
designates a cushion such as a rubber which comes into contact with the bottom of the spindle
110
. The cushion
162
buffers the impact on the bottom of the spindle
110
when the spindle
110
is lowered down to its lowermost position. A thrust bearing
160
is arranged on the spindle support
150
so as to ensure a smooth swivel of the chair with bearing the weight from above.
Referring to
FIG. 14
, the piston rod
130
has a piston rod head
187
which prevents the piston rod
130
from being separated from the piston
180
. The spindle
110
surrounds a cylinder
144
which has a smaller diameter than the spindle
110
. The spindle
110
has a buffer disposed in the spindle
110
for providing a comfortable feeling for the person seated thereon. The bottom of the spindle
110
is bent inward so as to prevent the piston
180
from escaping.
The spindle
110
houses a flange
183
disposed near the bottom thereof and a sealing member
184
disposed on the flange
183
for maintaining gas-tight in the cylinder
144
. Between the piston
180
and the sealing member
184
, an annulus
185
and a cylinder holder
186
are arranged in order from above. The cylinder holder
186
supports the bottom of the cylinder
144
.
The cylinder holder
186
has a gas-passing hole
186
a
formed through an outer portion of the cylinder holder
186
. The gas-passing hole
186
a
provides a path from the second chamber B to the third chamber C. Therefore, the gas-passing hole
186
a
enables the gas to flow from the first chamber A through the second chamber B into the third chamber C.
FIGS. 11A
,
11
B, and
11
C are respectively a partly cut-out perspective view, a perspective view, and a sectional view of an actuating pin socket
140
employed in the height-adjusting apparatus of a swivel chair according to the present invention as described above, and
FIG. 11D
is a sectional view of a socket body
140
a
of the actuating pin socket shown in
FIGS. 11A
,
11
B, and
11
C.
As shown in detail in
FIGS. 11A
to
11
D, the actuating pin socket
140
is integrally formed from materials of two kinds. The actuating pin socket
140
has a socket body
140
a
made from metal material and a socket coating
140
b
made from elastic material such as rubber. The actuating pin socket
140
has an actuating pin hole
141
formed through the center of the socket body
140
a
. The socket coating
140
b
is coated on the outer surface of the socket body
140
a
and the inner surface of the actuating pin hole
141
. The socket body
140
a
has relatively high hardness, while the socket coating
140
b
utilizes the elastic and flexible material to ensure the gas-tight characteristic in the actuating pin hole
141
and an O-ring function by a part of the outer surface of the socket body
140
a.
The actuating pin socket
140
can be manufactured by an mold, because the socket coating
140
b
is made from elastic material and can be easily escaped from the mold.
It is preferred that the socket body
140
a
has an annular reinforcement
140
c
protruding outward from a middle portion of the socket body
140
a
. The annular reinforcement
140
c
has an orifice
142
of a minute diameter formed through the annular reinforcement
140
c
of metal material, which can not be formed through the socket coating
140
b
of elastic material because the elastic material can block up the minute orifice
142
. The annular reinforcement
140
c
compensates for the loss of strength due to the formation of the orifice
142
. The socket coating
140
b
has a plurality of annular socket protuberances
145
protruding from the inner and outer surfaces of the socket coating
140
b.
FIGS. 12A
,
12
B, and
12
C are respectively a partly cut-out perspective view, a perspective view, and a sectional view of a piston employed in the height-adjusting apparatus according to the present invention as described above.
As shown, the piston
180
has a piston body
180
a
having a piston rod receiving hole
180
b
formed through the central portion of the piston body
180
a
. The piston body
180
a
is made from metal or hard synthetic resin and coated by a piston coating
180
c
made from elastic resin material such as rubber. The piston coating
180
c
has a plurality of annular protuberances
180
d
protruding from the inner cylindrical surface of the piston coating
180
c
in the piston rod receiving hole
180
b
and the outer cylindrical surface of the piston coating
180
c
coated on the outer surface of the piston body
180
a.
The annular protuberances
180
d
are made from the same elastic resin material as that of the piston coating
180
c
. When the piston rod
130
fitted in the piston
180
is assembled in the spindle
110
, the annular protuberance
180
d
protruding from the inner cylindrical surface of the piston coating
180
c
in the piston rod receiving hole
180
b
is in close contact with the piston rod
130
, and the annular protuberance
180
d
protruding from the outer cylindrical surface of the piston coating
180
c
is in close contact with the cylinder
144
contained in the spindle
110
, so as to provide gas-tight at the contact area.
Although
FIGS. 12A
,
12
B, and
12
C show a piston
180
having one annular protuberance
180
d
at each of the inner and outer surfaces of the piston body
180
a
, the number of the annular protuberance
180
d
may be changed according to necessity.
In the meantime, the piston
180
has a lower central recess
181
formed at the middle of the lower surface of the piston coating
180
c
, as shown in
FIGS. 12A and 12C
. Further, the piston rod
130
has an annular groove
188
a
corresponding to the lower central recess
181
as shown in FIG.
14
. The spring ring
188
and the annulus
185
surrounding the spring ring
188
are inserted in a space between the annular groove
188
a
and the lower central recess
181
, to apply a force in a radially inward and outward direction to the annular groove
188
a
and the lower central recess
181
, thereby firmly assembling the piston rod
130
and the piston
180
with each other.
As described above, the piston
180
does not require any O-ring member, which is replaced by the annular protuberance
180
d
integrally formed with the piston coating
180
c
. Therefore, the piston
180
of the present invention has a simple construction, which enables the piston
180
to be manufactured by a simple molding and to be mass-produced, thereby remarkably reducing the manufacturing cost.
FIG. 15
is an enlarged side elevation of the actuating pin
119
fitted in the actuating pin socket
140
in the spindle
110
shown in FIG.
13
. The actuating pin
119
has a small-diameter portion
119
a
, two large-diameter portions
119
b
, and two sloping portions
119
c
between the small-diameter portion
119
a
and each of the large-diameter portions
119
b
. The large-diameter portion
119
b
at the upper side has a chamfered surface
119
g
chamfered by R 0.2 to R 0.4, while the large-diameter portion
119
b
at the upper side has a washer head
119
f
functioning like a washer.
The entire actuating pin
119
including the small-diameter portion
119
a
, the large-diameter portion
119
b
, the sloping portion
119
c
, the washer head
119
f
, and the chamfered surface
119
g
is integrally formed from a single material. Therefore, the actuating pin
119
can be manufactured only by a finishing treatment after a single forming of the material without the step of assembling a separate washer, which enables mass production of the actuating pin
119
and reduces its manufacturing cost.
Preferably, the surface of the actuating pin
119
may be subject to nitriding, grinding, and then barrel finishing after the formation of the actuating pin
119
as described above, so as to have a surface hardness of HRC 40 to 60. Such a high hardness eliminates pinholes from the surface of the actuating pin
119
, thereby improving its gas-tight function. Further, in contrast to the conventional actuating pin consisting of several separate parts assembled together, the actuating pin
119
of the present invention reduces material and labor required in its manufacture, and simplifies its manufacturing process.
FIGS. 16 and 17
are a partly cut out enlarged view and a sectional view of shaft bearing members
400
according to embodiments of the present invention, which are employed in the height-adjusting apparatus as shown in FIG.
21
. The shaft bearing member
400
has a shape of a single annular ring whose upper and lower surfaces are curved surfaces
470
curved with a curvature ρ as shown in
FIG. 16
or tapered surfaces
480
tapered at an angle θ with respect to the horizontal line as shown in FIG.
17
. The shaft bearing member
400
has a shaft hole
460
formed through the center of the shaft bearing member
400
.
FIGS. 18 and 19
are a sectional view and a plan view of other shaft bearing members
400
according to other embodiments of the present invention, further to the shaft bearing members
400
of
FIGS. 16 and 17
. The shaft bearing member
400
may be manufactured from a material selected between a hard synthetic resin and a metal.
According to the embodiment shown in
FIG. 18
, the shaft bearing member
400
has a plurality of bearing protuberances
472
formed around the shaft hole
460
at the lower surface of the shaft bearing member
400
.
FIG. 19
shows another embodiment in which the bearing protuberances
472
are formed on the curved surface
470
or the tapered surface
480
. Although
FIG. 19
shows the shaft bearing member
400
having only six bearing protuberances
472
, the number of the bearing protuberances
472
may be chosen according to embodiments. The bearing protuberances
472
reduce the sliding resistance.
FIGS. 20A
,
20
B, and
20
C are plan views of retainer washers
190
according to several embodiments of the present invention and
FIG. 20D
is a side elevation of the retainer washers
190
, and
FIG. 21
is a partly cut-out enlarged view of an outer tube
120
containing the retainer washer
190
.
The retainer washer
190
for fixing the piston rod
130
is disposed between the thrust bearing
160
and the spindle support
150
. The retainer washer
190
has a plurality of retaining keys
191
protruding upward or downward from the inner circumference of the retainer washer
190
. The retaining keys
191
are engaged in plural piston rod grooves
192
having a shape of plural stripes formed on the cylindrical surface of the lower end of the piston rod
130
, so as to firmly fix the piston rod
130
.
It is preferred that the retainer washer
190
has an outer diameter of 10 mm to 30 mm and an inner diameter of 4 mm to 20 mm, and a thickness of 0.2 mm to 1 mm. The retainer washer
190
is made from metal or hard synthetic resin. Also, the retaining key
191
may have a width of 1 mm to 5 mm and a shape of a rectangle, a triangle, or a semi-circle as shown in
FIGS. 20A
to
20
C, or any other polygon.
This retainer washer
190
assembled with the piston rod
130
simplifies the assembling operation and reduces the working time, when the piston rod
130
is fixed to the spindle support
150
after the cylinder
144
and the piston rod
130
are inserted in the outer tube
120
.
Even in case the outer tube
120
and the cylinder
144
are separately handled or stored without being assembled together, the retainer washer
190
can be used to fix various parts such as the cushion
162
, the thrust bearing
160
, bearing supports, and etc. onto the piston rod
130
after they are fitted around the piston rod
130
. Therefore, the retainer washer
190
has a further advantage of easy handling and storing of parts.
Hereinafter, the operation of the height-adjusting apparatus of a swivel chair according to the present invention will be described in detail. When the actuating protuberance
114
shown in
FIG. 13
is pressed by means of the height-adjusting lever (not shown), the pushing rod
118
formed integrally with the actuating protuberance
114
pushes down the actuating pin
119
, similarly to the state shown in FIG.
6
.
When the actuating pin
119
is pushed down, the small-diameter portion
119
a
of the actuating pin
119
is lowered down so as to make the first chamber A and the central space
146
intercommunicate with each other. In this case, the gas in the first chamber A flows through the central space
146
, the connecting pore
147
a
and the orifice
142
into the second chamber B. Moreover, the gas flown into the second chamber B from the first chamber A continues to flow to the third chamber C through the gas-passing hole
186
a
shown in FIG.
14
.
As the gas in the first chamber A decreases while the gas in the third chamber C increases, the piston
180
is pushed up due to the change of the pressure difference between the two chambers, likewise with the state shown in FIG.
7
. In other words, the pressure of the gas in the third chamber C, which is larger than that in the first chamber A, pushes the piston
180
up and the spindle
110
down, to thereby lower the spindle
110
down because the piston
180
is fixed to the spindle support
150
of the outer tube
120
by means of the piston rod
130
.
In the height-adjusting apparatus of a swivel chair according to the present invention as described above, the holder body of the actuating pin holder is manufactured by an integral forming of a single material. Therefore, the holder body has a simple construction with reduced parts, and thereby enables its mass-production.
The piston also is manufactured by a simple coating of material after an integral forming of a single material, so that the piston also has a simple construction with reduced parts, and thereby enables its mass-production.
The actuating pin of the present invention is different from the conventional actuating pin which has a pin body and a separate washer, in that the actuating pin of the present invention does not require the steps of preparing the separate parts, and assembling the parts. Therefore, the actuating pin of the present invention reduces its manufacturing steps and cost.
The shaft bearing member of the present invention has a simple construction consisting of only one body, thereby minimizing the sliding resistance, improving its durability, and reducing the parts such as balls and bearings. Further, the shaft bearing member can be manufactured by a simple metal mold, which results in the decrease of the manufacturing cost.
The retainer washer for fixing the piston rod to the outer tube simplifies the fixing operation and makes many parts be easily handled and stored even when they are not assembled.
While the present invention has been particularly shown and described with reference to the particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be effected therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims
- 1. An apparatus for adjusting the height of a swivel chair, said apparatus comprising:an outer tube rotatably fitted in a seat of the swivel chair; a spindle slidably inserted in the outer tube, the spindle containing a cylinder fixed in the spindle by means of a cylinder holder disposed at a lower position of the spindle; a piston rod fixedly contained in the outer tube and slidably inserted in the spindle through a bottom of the spindle; an actuating pin socket fixed at a top of the cylinder, the actuating pin socket having a socket body and a socket coating coated on the socket body, the socket body having an actuating pin hole and an orifice formed in the socket body, and an annular reinforcement protruding outward from a middle portion of the socket body, the actuating pin socket being manufactured by an integral single forming, the orifice being formed through the annular reinforcement; an actuating pin slidably fitted in the actuating pin hole; and, a piston fixed at an upper portion of the piston rod and slidably fitted in the cylinder, the actuating pin socket and the piston defining a first chamber above the piston in the cylinder, the spindle and the cylinder defining a second chamber between the spindle and the cylinder, the piston and the cylinder defining a third chamber under the piston in the cylinder, the orifice of the socket body being connected to the second chamber, the second chamber and the third chamber communicating through a gas-passing hole formed through an outer portion of the cylinder holder, the first, the second, and the third chambers containing working fluid, wherein, the actuating pin opens the orifice to communicate the first chamber with the second chamber so that working fluid can flow from the first chamber through the second chamber into the third chamber when the actuating pin is pressed down, while the actuating pin blocks up the orifice when the actuating pin is not pressed down.
- 2. The apparatus as claimed in claim 1, wherein the socket coating comprises a plurality of annular socket protuberances protruding from inner and outer surfaces of the socket coating, the annular socket protuberances functioning like O-rings.
- 3. The apparatus as claimed in claim 1, wherein the actuating pin hole is formed through a center of the socket body, the socket coating being coated on an inner cylindrical surface of the socket body in the actuating pin hole.
- 4. The apparatus as claimed in claim 1, wherein the piston comprises a cylindrical piston body and a piston coating coated on the piston body, the piston body being manufactured by an integral single forming and being made from metal, and the piston coating being made from elastic resin material with at least one annular protuberance.
- 5. The apparatus as claimed in claim 1, wherein the actuating pin has a surface hardness of HRC 40 to 60 by being subject to a treatment of barrel finishing.
- 6. The apparatus as claimed in claim 1, said apparatus further comprising a shaft bearing member provided at a bottom of the piston rod in the outer tube to bear a weight transferred through the piston rod, wherein the shaft bearing member has a shape of a single annular ring whose upper and lower surfaces are curved surfaces curved with a predetermined curvature.
- 7. The apparatus as claimed in claim 6, wherein the shaft bearing member comprises a plurality of bearing protuberances formed around a shaft hole at the lower surface of the shaft bearing member, the shaft hole being formed through a center of the shaft bearing member.
- 8. The apparatus as claimed in claim 6, wherein the shaft bearing member comprises a plurality of bearing protuberances formed on a middle portion of the curved surface.
- 9. The apparatus as claimed in claim 6, wherein the shaft bearing member is made from material selected from the group consisting of metal and hard synthetic resin.
- 10. The apparatus as claimed in claim 1, said apparatus further comprising a shaft bearing member provided at a bottom of the piston rod in the outer tube to bear a weight transferred through the piston rod, wherein the shaft bearing member has a shape of a single annular ring whose upper and lower surfaces are tapered surfaces tapered at a predetermined angle.
- 11. The apparatus as claimed in claim 10, wherein the predetermined angle is an angle within 1° to 30°.
- 12. The apparatus as claimed in claim 1, said apparatus further comprising means for fixing the piston rod, said fixing means being disposed between a thrust bearing and a spindle support fitted around the piston rod.
- 13. The apparatus as claimed in claim 12, wherein said fixing means is a retainer washer having a plurality of retaining keys protruding upward from an inner circumference of the retainer washer, the retaining keys being engaged in a plurality of piston rod grooves formed on a cylindrical surface of a lower end of the piston rod, so as to firmly fix the piston rod.
- 14. The apparatus as claimed in claim 12, wherein said fixing means is a retainer washer having a plurality of retaining keys protruding downward from an inner circumference of the retainer washer, the retaining keys being engaged in a plurality of piston rod grooves formed on a cylindrical surface of a lower end of the piston rod, so as to firmly fix the piston rod.
Priority Claims (5)
Number |
Date |
Country |
Kind |
97-32398 |
Nov 1997 |
KR |
|
98-11376 |
Jun 1998 |
KR |
|
98-24913 |
Jun 1998 |
KR |
|
98-12951 |
Jul 1998 |
KR |
|
98-28313 |
Jul 1998 |
KR |
|
US Referenced Citations (8)