JP3099221B2 - Overhead door - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door, in which a door is closed in a hanging state in a door mounting body such as a cabinet, and the door is opened upward from this state. The present invention relates to an overhead door which is stored on a top plate so as to be able to hold the open state.

[0002]

2. Description of the Related Art Conventionally, in an overhead door,
As shown in FIG. 5, when the door a is inside the door mounting body b,
There is known one that is stored in the lower back side of the top plate c (Japanese Utility Model Publication No. 60-18528).

However, in the above-mentioned overhead door, a supporting rod d and a short rod e for opening and closing the door a by turning the door a in the vertical direction are attached to the door a and the door mounting body b. Not only stretch the spring f
Since the slide mechanism by the slide rail g and the door wheel h is internally provided, it is difficult to perform the mounting operation of the door a and the position adjustment operation of the door a after the door is mounted, or the door a is located inside the door mounting body b. Since it is stored, there is also a disadvantage that the storage space inside the door mounting body b is narrowed.

Further, when the door a is opened, the supporting rod d and the spring f are exposed, so that the appearance is poor, and the fingertip is erroneously inserted between the spring f and the spring f and the supporting rod d during opening and closing operations. There is also a danger of being pinched.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and in the first aspect, by appropriately adopting a support arm and a slide rail,
The door opened by the upward rotation can be stored on the top plate of the door mounting body as it is, so that the door and its attachment mechanism do not hinder the loading and unloading of the storage object. But that is the purpose.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a tension spring is provided in the groove on the back surface of the door so that the tension spring is not separated from the door when the door is opened or closed. By doing so, during the operation of opening and closing the door, so as not to pinch fingertips and the like in the tension spring, and furthermore, by the tension spring,
The door closing operation can be performed slowly and the opening operation
It can also be easily performed with a light force.

According to a third aspect of the present invention, there is provided the mechanism of the first aspect, wherein the both ends of the support arm are provided between the inner surface of the side plate and the door simply in a door mounting body such as a cabinet. Instead of pivoting, one end of the support arm is pivotally attached to the inner surface of the side plate of the door mounting body via a damper, so that the door is opened and stored on the top plate of the door mounting body. When the door is to be closed from the state described above to the closed state, the closing operation of the door can be performed slowly without an impact by the resistance force of the damper, that is, the buffer action against the door load torque.

According to the fourth aspect of the present invention, the door closing operation can be performed smoothly and gently by using the damping force of the damper as in the third aspect of the present invention. By setting the tension spring as described in FIG. 2 in a proper position, the closing movement of the door at the time of closing the door can be performed more smoothly and gently, and the restoring force accumulated by the extension of the tension spring. Thus, the door opening operation can be performed lightly.

According to a fifth aspect of the present invention, in the configuration of the third aspect, by appropriately attaching a coil spring to the damper, the coil spring can be used when the door is closed. In addition to the damping force of the damper, the braking force of the coil spring is also added, so that the closing movement of the door can be performed more gently. the restoring force, which is prestressed in a spring by effectively utilizing the operation of opening the door, so that can perform more lightly.

According to a sixth aspect of the present invention, in addition to the configuration according to the fifth aspect, a tension spring as in the fourth aspect is also added, so that when the door is closed, only the braking force by the damper is applied. In addition, by exerting a braking force based on the above-described coil spring, a sufficiently slow closing movement of the door is performed, and when the door is to be opened, the tension spring and the coil spring described above are used. The opening operation can be performed with a lighter force by utilizing the restoring force.

[0011]

According to the present invention, in order to attain the above object, according to the present invention, a shaft is provided on an inner surface of a side plate of a door mounting body such as a cabinet so that a base end of a support arm is rotatable. And the front end is pivotally attached to the vicinity of the lower end of the back surface of the door, while the outer back surface of the door is slidably engaged with a long outer rail and a short inner rail via a ball retainer. The slide rail of the above, the outer rail is provided long in the up and down direction, the door can be opened and closed in the up and down direction by turning and sliding, and so that it can be placed on the top plate of the door mounting body, It is intended to provide an overhead door characterized in that the upper end of the inner rail is pivotally connected to the front edge of the top plate of the door mounting body via a hinge.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a concave groove is formed in the back surface of the door so as to be long in the vertical direction, and a tension spring is provided in the concave groove. Ends are respectively extended and mounted on the upper end of the hinge and the lower end of the concave groove, and the lowering of the outer rail and the door is controlled with respect to the inner rail by the tension spring. The content is that the movement is energized.

In the case of a third aspect, a damper is fixed to an inner surface of a side plate of a door mounting body such as a cabinet, a base end of a support arm is fixed to a rotation shaft of the damper, and a tip of the support arm is a lower end of a back surface of the door. On the other hand, on the other hand, the outer rail of the slide rail, in which a long outer rail and a short inner rail are slidably engaged via a ball retainer on the back surface of the door, The upper end of the inner rail is attached to the door mounting body so that the door can be opened and closed in the vertical direction by rotation and sliding, and can be placed on the top plate of the door mounting body. It is an object of the present invention to provide an overhead door characterized in that the door is pivotally attached to a front edge of a top plate via a hinge.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, a concave groove is provided on the back surface of the door so as to be long in the vertical direction, and a tension is provided in the concave groove. Each end of the spring is hung on the upper end of the hinge and the lower end of the concave groove, respectively, and the outer rail and the door are moved downward with respect to the inner rail by the tension spring. Is controlled, and the movement is energized.

According to a fifth aspect of the present invention, a damper is fixed to an inner surface of a side plate of a door mounting body such as a cabinet, and a base end of a support arm is fixed to a rotation shaft of the damper. On the other hand, the outer rail of the slide rail, which is pivotally mounted in the vicinity, on the back surface of the door, is formed by slidably engaging a long outer rail and a short inner rail via a ball retainer. The upper end of the inner rail is located in front of the top plate of the door mount so that the door can be opened and closed in the vertical direction by turning and sliding, and can be placed on the top plate of the door mount. The rim is pivotally attached to the rim via a hinge, and the damper is further provided with a coil spring by rotation in a door closing direction.
In order to be able to be screwed in the winding direction, the ends are mounted on the rotating shaft side and the main body side of the damper, respectively, and the outer rail and the door are separated from the inner rail by the restoring force of the coil spring. It is intended to provide an overhead door characterized by being biased upward.

According to the sixth aspect, in addition to the fifth aspect, a concave groove is formed in the back surface of the door so as to be vertically long, and a tension spring is provided in the concave groove. Each end is respectively hung and stretched at the upper end of the hinge and the lower end of the concave groove, and the downward movement of the outer rail and the door is controlled with respect to the inner rail by the tension spring, In addition, the movement is to be energized, the contents.

[0017]

In the overhead door according to the first aspect, the lower end of the door that is closed in a suspended state is held, and when this is pulled up, the lifting force is opened to the support arm through the door. The door is opened because it is applied as a turning force in the direction of the door.

When the pivot point between the door and the support arm is rotated to a position higher than the pivot point between the support arm and the side plate of the door mount, the inner rail is hinged to the front edge of the top plate of the door mount. Since the door is rotatably pivoted, the door is pivoted upward by the hinge and the outer rail is fixed to the door, so the outer rail slides upward with the door with respect to the inner rail, The door rotates while sliding toward the upper side of the top plate of the door mounting body, and is opened and mounted on the top plate in a horizontal state.

From the above storage state, hold the front end of the door,
If you pull out the front end of the door after pulling out to the near side, the pressing force is applied to the support arm via the slide rail,
Since the slide rail is applied as a rotational force in the opposite direction to the above-described opening, the slide rail rotates around the hinge axis,
On the other hand, the door is pivoted about a pivot point between the base end of the support arm and the side plate of the door mount. After rotating the door by a predetermined angle,
The door rotates and descends due to the load torque of the door, and the door is closed.

Next, in the case where a tension spring is added to the above-described first aspect, if the lower end of the door is held and opened as described above, the present invention will be described. Similarly, when the pivot point between the door and the support arm is rotated to a position higher than the pivot point between the support arm and the side plate of the door mounting body, the inner rail moves to the front edge of the top plate of the door mounting body. Since the hinge is rotatably pivoted by the hinge and is provided with a tension spring, the tension of the tension spring generates a moment to rotate the door upward, and the outer rail is fixed to the door, so that the inner rail is fixed. The outer rail slides upward with the door with respect to the rail, and the door rotates while sliding toward the upper side of the top plate of the door mounting body, and is opened and mounted on the top plate in a horizontal state. You.

Further, when the door is opened as described above, the door slides rearward due to the tension of the tension spring, and comes to a horizontal open position on the top plate of the door mounting body, and the hand is released from the door. Also, the door is held in an open state, and is held in a housed state placed on a top plate.

From the above storage state, hold the front end of the door,
If this is pulled out to the front side against the tension of the tension spring, as described in claim 1, when the front end of the door is depressed, the depressing force is applied to the support arm via the slide rail and at the time of the opening described above. The slide rail rotates about the hinge axis, while the door is rotated about the pivot point between the base end of the support arm and the side plate of the door mounting body. . After the door is rotated by a predetermined angle, the door is rotated down by the load torque of the door to be in a closed state. According to claim 2, at the time of the door closing operation as described above, the tension spring is extended, When the door is opened next time, a tension for lightly opening the door is accumulated.

According to the third aspect, since the base end of the support arm in the first aspect is not directly supported on the inner surface of the side plate of the door mounting body, the support arm is configured to be supported via a damper. At the time of the detailed door opening operation,
Although the rotation axis of the damper is rotated, no resistance is generated by the damper. Therefore, the door is rotated without resistance, and is opened horizontally on the top plate of the door mounting body as described above. Is placed. On the other hand, when the door is closed, the rotation shaft and the inner cylinder (not shown) are rotated in the opposite direction to the above-described opening with respect to the main body of the damper. The damper exerts a braking force against the load torque of the door, and the door rotates slowly.
It will be in the closed state suspended .

According to the fourth aspect of the present invention, a tension spring is added to the third aspect of the invention, and the operation of the tension spring is as described in the second aspect. At the time of opening, the resistance generated by the damper is generated, and the extension spring is sufficiently extended in the opened state to accumulate the restoring force, so that the opening operation of the door is assisted by the restoring force. 2 and the opening operation state is substantially the same.

Further, when the door is closed, not only the damper gives a resistance to the door to be closed as in the case of claim 3, but also a tension spring when the door is closed. Since a resistance is given to the movement, the resistances of the above two are added, and a more reliable and effective closing even for a heavy door can be achieved. .

Further, according to the fifth aspect of the present invention, since the coil spring is added to the damper in the configuration of the third aspect, no resistance is generated by the damper when the door is opened. Since the above coil spring is in a state of being closed and being entrained and accumulating the restoring force,
The opening operation of the door is assisted by the restoring force, so that a light opening operation can be guaranteed.

When the door is closed, the resistance by the damper acts as described above, and the coil spring is involved. Therefore, the resistance generated at this time is added to the resistance by the damper, and the door is closed. By applying a sufficient braking force when closing the door, the door can be closed slowly.

In the case of the sixth aspect, since the tension spring according to the fourth aspect is used in combination with the configuration of the fifth aspect, the resistance force of the damper acts when the door is opened. Instead, the coil springs and the tension springs can use both the restoring forces of the stored energy, so that the door opening operation can be performed with a lighter force.

Further, when the door is closed, not only the resistance force of the damper is exerted, but also the resistance force of the coil spring and the tension spring is added thereto, so that the door is further slowly moved. A simple closing operation can be realized with high reliability.

[0030]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 is a vertical cross-sectional view showing the configuration of the overhead door according to the first embodiment in a closed state, FIG. 2 is a cross-sectional view taken along a line II-II in FIG. 3 in an open state, and FIG. This will be described in detail below with reference to FIG. 3 which is a cross-sectional view and FIG. 4 which is a partially cutaway side view showing an additional configuration of the coil spring according to claims 5 and 6. A door mounting body 1 such as a cabinet or the like according to the present invention is formed in a box shape having an opening 6 on the front surface by a top plate 2, a bottom plate 3, left and right side plates 4 and a back plate 5. At the left and right sides of the edge, mounting recesses 7 for attaching a hinge 10 described later are cut out.

The door 8 is formed in a thick plate shape, and
The height and the width of the outset are set so that the outset is externally attached to the front surface of the opening 6 at the right side. On the left and right sides of the back surface, slide rails 9 and 9 are provided with the outer rails. By fixing 9c,
It is installed side by side vertically.

[0032] The slide rail 9, Figure as is well known
3 , a long outer rail 9c and a short inner rail 9d are slidably engaged with each other via a ball retainer 9b which rotatably holds a plurality of steel balls 9a # specified in 3 . A wide hinge 10 is connected to the short inner rail 9d.
The hinge 10 has two plate-shaped hinge bodies 10a, 1
0b are pivotally connected to each other so as to be freely opened and closed by a support shaft 10c.
Are formed, one of the hinge body 10a described above is,
The inner rail 9 is fixed to the rear surface of the door 8 . The above configuration is common to all of claims 1 to 6.

Further, on the back surface of the door 8, in the second, fourth, and sixth aspects, the right and left sides of the slide rails 9, 9 are shown in FIGS. By
As can be understood, the concave grooves 12, 12 for housing the tension springs 11, 11 are provided long in the vertical direction.

[0034] The above tension spring 11 and 11, one end thereof In the upper end of the hinge 10, a spring hook 10d projecting from the right and left sides, seals hanging to 10d, the other end,
A spring hook 13 implanted at the lower end of the concave grooves 12, 12;
By being hooked on the groove 13, it is stretched in the groove 12.

Furthermore, the door 8 as described above, the hinge body 10b of the other side in front Symbol hinge 10 common to all the claims
Is located in the recess 7 at the front edge of the top plate 2 of the door mounting body 1 and is fixed by screws (not shown) , whereby the door 8 is vertically moved about the support shaft 10 c of the hinge 10. It is pivotally mounted so as to be rotatable in the direction. As a result, the outer rail 9 is positioned relative to the inner rail 9d.
c, and the door 8 fixed thereto is slidable in the vertical direction, and when the tension springs 11, 11 are provided as in claims 2, 4, and 6, the door 8 is extended in the closed state. By the tension based on the restoring force of the tension springs 11, 11, the springs are urged in the door opening direction. In the illustrated embodiment, not only the tension springs 11, but also the slide rails 9, 9 are formed on the back surface of the door 8 by the concave groove 1.
The slide rails 9 and 9 are not attached to the concave grooves 12 and 12, but are attached to the slide rails 9 and 9.
It can also be mounted on the back surface.

Further, brackets 16 are protruded in the vicinity of the left and right lower ends on the back surface of the door 8, and the front ends of the respective support arms 14, 14 are rotatably pivotally mounted on the brackets 16. However, in the first and second aspects, the base end of each of the support arms 14 and 14 is
Are supported on the inner surfaces of the left and right side plates 4, 4 at the upper end side from the center thereof so as to be rotatable by a rotating shaft 15. Therefore, the door 8 is, as shown in FIGS.
It is opened by rotating up the support arms 14 and 14 as a radius, and can be closed by rotating down.

Further, in claims 3 to 6,
As shown in FIG. 3, the base ends of the support arms 14, 14 are on dampers 17, 17 which are disposed by fixing the main body 17a to the inner surfaces of the side plates 4, 4, as described above in FIG. It is fixed, and when the door is closed, the dampers 17, 17
As a result, a buffer action against the door load torque, that is, a braking force is applied to the door, so that a gentle door closing operation can be obtained.

Here, as shown in FIG. 2, the dampers 17, 17 are horizontal and the door 8 in the opened state is indicated by an arrow A.
The braking force is exerted only when rotating in one direction, which is closed by rotating down in the direction, and when rotating in the opposite direction, that is, rotating up in the direction of arrow B shown in FIG. At the door,
The door 8 is set to be able to rotate lightly by a spring (not shown).

Further, in claims 5 and 6,
The dampers 17, 17 are different from the third and fourth embodiments in that a coil spring 18 is additionally provided as will be described in detail below. That is, in the example illustrated in FIG. 4, the main body 17a is fixed to the inner surface of the side plate 4 and the rotating shaft 15 is not fixed to the support arm 14 as shown in FIG. The shaft 15 is erected, and the main body 17a is continuously attached to the support arms 14, 14, so that the main body 17a provided on the outer periphery of the rotary shaft 15 is rotated. 18 is connected to the substrate 1
9 and the other end 18b are locked to the main body 17a, respectively.

As in the above embodiment, in the fifth and sixth aspects, the end of the coil spring 18 is rotated so that the coil spring 18 is eventually screwed in the winding direction by the rotation in the door closing direction. The outer rail 9c and the door 8 can be urged upward by the restoring force of the coil spring 18 on the shaft 15 side and the main body 17a of the dampers 17, 17, respectively.

Therefore, according to the embodiment of FIG.
Only when the door 8 in the horizontally opened state is turned in one direction in which the door 8 is turned down and closed, the braking force as the dampers 17, 17 is exerted, and the coil spring 18 is moved in the winding direction. The resistance force at this time acts on the main bodies 17a of the dampers 17, 17, and the restoring force of the coil spring 18 obtained at the time of opening the door when the door is turned upward is opened. It will act as a door force.

[0042]

According to the present invention, as described above, according to the first aspect, a hinge and a support arm are provided so that the door can be opened and closed by pivoting with respect to the door mounting body. After being pivoted and opening the door,
It is mounted via a slide rail so that it can be moved backward and slide freely by pulling out,
In addition, since the opened door is stored on the top plate of the door mounting body, the door and its attachment mechanism do not hinder the taking in and out of the storage object, and the storage space inside the door mounting body is widened. Can also be taken.

According to the second aspect, in the configuration of the second aspect, the tension spring is stretched between the hinge and the lower end of the concave groove of the door, so that the tension spring and the slide rail are used. , door, which,-out line is retracted and at the same time opened, in the time of closing, by working tension by the tension spring against the door load torque, such as to support a large force against the door load torque Since the door can be closed without necessity, and this tension spring is attached to a groove provided vertically on the back surface of the door and does not separate from the door when the door is opened, the door is opened. The appearance is good in appearance, and the danger of accidentally pinching a fingertip or the like with a tension spring or the like during door opening / closing operation can be eliminated, which is safe.

According to the third aspect, in addition to the effect of the first aspect, the damper exerts a buffering action on the door load torque, that is, a braking force is exerted on the door. Closure is prevented, without impact,
A gradual closing operation can be obtained.

In the case of the fourth aspect, in addition to the effect of the second aspect, the spring force of the tension spring and the damping function of the door load torque, that is, the braking force on the door, can be obtained. This prevents abrupt closing of the door, and provides a gentler closing operation with less impact.

According to the fifth aspect, in addition to the effect of the third aspect, the coil spring suppresses not only the braking force by the damper when the door is closed but also the closing of the door. Thus, a gradual closing operation can be performed, and when the door is opened, the door can be opened with a small force by the restoring force of the coil spring.

In the overhead door according to the sixth aspect, in addition to the effect according to the fifth aspect, the action based on the tension spring according to the fourth aspect is exhibited.
A gradual closing operation when the door is closed by the coil spring and the tension spring, and an assisting effect on the opening operation by the coil spring and the tension spring when the door is opened, and the respective effects when the door is opened and closed are promoted. can do.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a closed state of an overhead door according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG. 3, showing a storage state of the door opened according to the embodiment of FIG. 1;

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a partially cutaway side view of a damper using a coil spring according to claims 5 and 6 of the present invention.

FIG. 5 is a longitudinal sectional view showing a conventional overhead door.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Door mounting body 2 Top plate 4 Side plate 8 Door 9 Slide rail 9b Ball retainer 9c Outer rail 9d Inner rail 10 Hinge 11 Tension spring 12 Concave groove 14 Support arm 15 Rotation axis 17 Damper 18 Coil spring 18a Coil spring end 18b End of coil spring

Claims (6)

(57) [Claims] 1. A base end of a support arm is rotatably supported on an inner surface of a side plate of a door mounting body such as a cabinet so as to be rotatable.
The front end of the slide rail is pivotally mounted near the lower end of the back of the door, while the back of the door is slidably engaged with a long outer rail and a short inner rail via a ball retainer. The outer rail is vertically long, and the upper end of the inner rail is provided so that the door can be opened and closed in the vertical direction by turning and sliding, and can be placed on the top plate of the door mounting body. An overhead door, wherein the door is pivotally connected to a front edge of a top plate of a door mounting body via a hinge. 2. A base end of a support arm is rotatably supported on an inner surface of a side plate of a door mounting body such as a cabinet so as to be rotatable.
The front end of the slide rail is pivotally mounted near the lower end of the back of the door, while the back of the door is slidably engaged with a long outer rail and a short inner rail via a ball retainer. The outer rail is vertically long, and the upper end of the inner rail is provided so that the door can be opened and closed in the vertical direction by turning and sliding, and can be placed on the top plate of the door mounting body. Is pivotally attached to the front edge of the top plate of the door mounting body via a hinge, and a concave groove is vertically long on the back surface of the door, and a tension spring is provided in the concave groove. Each end is respectively hung and stretched at the upper end of the hinge and the lower end of the concave groove, and the lowering of the outer rail and the door is controlled with respect to the inner rail by the tension spring, Upward movements are now energized Overhead door which is characterized. 3. A damper is fixed to an inner surface of a side plate of a door mounting body such as a cabinet, a base end of a support arm is fixed to a rotating shaft of the damper, and a tip of the damper is pivotally mounted near a lower end of a back surface of the door. On the other hand, on the back surface of the door, a long outer rail and a short inner rail are slidably engaged via a ball retainer. The upper end of the inner rail is hinged to the front edge of the top plate of the door mount so that the door can be opened and closed in the vertical direction by rotation and sliding, and can be placed on the top plate of the door mount. An overhead door, characterized in that it is pivotally connected via a door. 4. A damper is fixed to an inner surface of a side plate of a door mounting body such as a cabinet, a base end of a support arm is fixed to a rotation shaft of the damper, and a tip of the damper is pivotally mounted near a lower end of a back surface of the door. On the other hand, on the back surface of the door, a long outer rail and a short inner rail are slidably engaged via a ball retainer. The door can be opened and closed in the vertical direction by rotation and sliding, and the upper end of the inner rail is hinged to the front edge of the top plate of the door mount so that the door can be placed on the top plate of the door mount. While being pivotally connected, a concave groove is formed in the back surface of the door so as to be long in the vertical direction. A tension spring is provided in the concave groove, and each end thereof has an upper end of the hinge and a concave groove. And the lower end of the strip An overhead door, wherein the downward movement of the outer rail and the door is controlled with respect to the inner rail by a tension spring, and the upward movement is urged. 5. A damper is fixed to an inner surface of a side plate of a door mounting body such as a cabinet, and a base end of a support arm is fixed to a rotation shaft of the damper, and a tip of the damper is pivotally connected to a vicinity of a lower end of a back surface of the door. On the other hand, on the back surface of the door, a long outer rail and a short inner rail are slidably engaged via a ball retainer. The upper end of the inner rail is hinged to the front edge of the top plate of the door mount so that the door can be opened and closed in the vertical direction by pivoting and sliding, and can be placed on the top plate of the door mount. Further, a coil spring is attached to the damper so that the coil spring can be screwed in the winding direction by rotation in the door closing direction, and the ends of the coil spring are respectively attached to the rotation shaft side and the damper body side. Install and arrange An overhead door, wherein the outer rail and the door are biased upward with respect to the inner rail by the restoring force of the coil spring. 6. A damper is fixed to an inner surface of a side plate of a door mounting body such as a cabinet, a base end of a support arm is fixed to a rotation shaft of the damper, and a tip of the damper is pivotally connected to a vicinity of a lower end of a back surface of the door. On the other hand, on the back surface of the door, a long outer rail and a short inner rail are slidably engaged via a ball retainer. The upper end of the inner rail is hinged to the front edge of the top plate of the door mount so that the door can be opened and closed in the vertical direction by pivoting and sliding, and can be placed on the top plate of the door mount. At the same time, a concave groove is vertically recessed on the back surface of the door, and a tension spring is provided in the concave groove. It is installed at the lower end of the groove, respectively. The extension spring controls the lower movement of the outer rail and the door with respect to the inner rail, and biases the upper movement thereof. Further, the damper is provided with a coil spring and a door closing mechanism. By rotating in the forming direction, the ends are respectively mounted on the rotating shaft side and the main body side of the damper so that the ends can be screwed in the winding direction, and the restoring force by the coil spring causes the inner rail to move relative to the inner rail. An overhead door, wherein the outer rail and the door are biased upward.