JP7474535B1 - Door opening actuator - Google Patents

Abstract

[Problem] The object of the present invention is to provide a means for improving various existing doors that are locked in the closed position so that they can be automatically opened by simply unlocking them. [Solution] A door opening biasing device 12 is attached to a side frame 3 on which a door body 5 is supported so as to be freely opened and closed, and includes a vertically long base plate 16 attached to the inside of the side frame 3, a vertically long gas spring 18 with one end attached to the upper end of the base plate and hanging down, a rotor 27 supported on the lower end of the base plate 16 so as to be rotatable about a vertical axis, a transmission means 31 for converting the vertical movement of a retractable portion 18a protruding from the lower end of the gas spring into rotation of the rotor 27, and an arm 13 extending horizontally from the rotor 27 in a direction away from the side frame 3, and the downward biasing force of the retractable portion 18a of the gas spring causes the tip of the arm 13 to press against the inner surface of the door body 5, biasing the door body 5 in the opening direction. [Selected Figure] Figure 4

Description

The present invention relates to a door opening and closing biasing device that can be used as a means to automatically open openable doors used in various storage furniture and partitions when the doors are unlocked in the closed position and become openable.

For example, taking the folding door shown in Patent Document 1 as an example, folding doors generally have a function in which the hinge between the door bodies, which connects two door bodies so that they can be foldable, automatically engages with the hinge between the door bodies to automatically lock the folding door in the closed, flat state when the folding door is closed in a flat state to close the opening. Therefore, if a person who wants to open the opening pulls one of the door bodies outward with a certain amount of operating force using a handle provided near the side where the two door bodies are connected by the hinge between the door bodies, the automatic lock mechanism is released, and the person can then pull one of the door bodies outward with the handle to fold the folding door and open the opening. In this way, various doors that open and close openings can be opened by releasing the lock on the door in the closed position, but no practical means for automatically opening and closing the door have been considered.

Japanese Patent Application Laid-Open No. 8-270308

For example, to automatically open an unlocked door, it would be sufficient to combine it with a biasing means that applies a biasing force in the opening direction to the door, but this biasing means must be interposed between the door body and the surrounding side frames, etc., which would require modification of the door body and side frames, and it would not be easy to retrofit it to an existing door. Furthermore, there are also anticipated problems with the biasing means getting into the storage space inside the door, narrowing the original storage space or interfering with the insertion and removal of stored items.

The present invention proposes a door opening biasing device that can solve the above problems. The door opening biasing device of the present invention is, in order to make it easier to understand the relationship with the embodiments described below, a door opening biasing device (12) that is attached to a side frame (3) on which a door body (5) is supported so as to be freely opened and closed, and includes a vertically elongated base plate (16) that is attached to a position close to the door body (5) on the inside of the side frame (3), a vertically elongated gas spring (1) that is attached to the upper end of the base plate (16) and hangs down. 8), a rotor (27) supported on the lower end of the base plate (16) so as to be rotatable about a vertical axis, a transmission means (31) that converts the vertical movement of the retractable part (18a) protruding from the lower end of the gas spring (18) into rotation of the rotor (27), and an arm (13) that extends horizontally from the rotor (27) in a direction away from the side frame (3). The downward biasing force of the retractable part (18a) of the gas spring (18) causes the tip of the arm (13) to press against the inner surface of the door body (5), biasing the door body (5) in the opening direction.

According to the above-mentioned configuration of the present invention, if the locking means that locks the door body in the closed position is opened manually or by other means, the door body will automatically open due to the biasing force of the gas spring, since the biasing force of the gas spring is constantly acting on the door body via the arm in the opening direction. If the biasing force of the gas spring is configured to continue until the door body reaches its opening limit, the door body can be opened reliably and automatically to the opening limit without relying on human labor. To close the open door body, the door body can be biased in the closing direction with human force that overcomes the biasing force of the gas spring, and closed to the closing limit position where it is locked.

As described above, the door body can be opened automatically and reliably by the force of the gas spring without relying on human hands. According to the configuration of the present invention, the door opening biasing device of the present invention is installed vertically long inside the side frame that supports the door body to be opened and closed, adjacent to the inside of the door body in the closed position, and the tip of the arm that protrudes horizontally and swingably from the lower end of this door opening biasing device is brought into sliding contact with the inner surface of the door body, so that there is no need to specially process the door body or side frame, and the door of an existing facility can be easily improved to an automatic opening door. In addition, the door opening biasing device of the present invention is vertically long as described above, and even if a high-performance gas spring that becomes longer is used, the vertical length of the door opening biasing device will only increase, and there is no risk of the door opening biasing device (gas spring) penetrating deep into the storage space opened and closed by the door improved to automatic opening with this door opening biasing device. Therefore, even if the opening and closing doors of existing storage facilities are improved to automatic opening and closing doors using the door opening and closing biasing device of the present invention, the internal storage space is not significantly narrowed, and the door opening and closing biasing device rarely interferes with the insertion and removal of stored items.

When implementing the present invention, specifically, the transmission means (31) is composed of a vertical bevel gear (22) that rotates integrally with the rotating body (27), a horizontal bevel gear (20) that is supported by a horizontal support shaft (21) on the base plate (16) and engages with the bevel gear (22), and a passive member (24) that rotates integrally with the horizontal bevel gear (20) around the horizontal support shaft (21) and to which the advance/retract movement part (18a) of the gas spring (18) is supported at an eccentric position, so that the downward movement of the advance/retract movement part (18a) of the gas spring (18) is transmitted to the rotating body (27) via the horizontal bevel gear (20) and the vertical bevel gear (22). With this configuration, the entire transmission means can be configured simply and in a small space compared to when the transmission means is configured by a link mechanism.

In addition, a plate (15) large enough to cover the sliding area of the tip of the arm (13) can be attached to the inner surface of the door body (5) with which the tip of the arm (13) is pressed, and a sliding member (14) that slides against the plate (15) can be attached to the tip of the arm (13). With this configuration, the biasing force of the gas spring can be smoothly transmitted to the door body to be opened, allowing the door body to be opened smoothly, and also preventing large scratches on the inner surface of the door body to be opened.

When the above-mentioned configuration is adopted, a through hole (37) is provided at the tip of the arm (13) penetrating the arm (13) in the thickness direction, and the sliding member (14) is provided with a recessed portion (38) into which the tip of the arm (13) is inserted, openings (38a, 38b) provided on both sides of the recessed portion (38) so as to be adjacent to both sides in the thickness direction of the arm (13) within the recessed portion (38), and a A cantilevered elastic tongue portion (39) and an engagement protrusion (40) at the tip of the elastic tongue portion (39) can be provided so as to automatically fit into the through hole (37) when the tip of the arm (13) is inserted into the recessed portion (38), and the engagement protrusion (40) fitted into the through hole (37) can be pushed out of the through hole (38b) from the other opening (38b against the elasticity of the elastic tongue portion (39). With this configuration, a metal plate is used as the plate attached to the door body, and a plastic molded product that slides easily against the metal plate is used as the sliding member at the tip of the arm, eliminating the risk of scratching the door body, and when the sliding member needs to be replaced due to wear, the sliding member can be easily removed from the tip of the arm compared to a configuration in which the sliding member is screwed to the tip of the arm. Of course, the operation of attaching the sliding member to the end of the arm can be done simply by inserting the sliding member over the end of the arm, so the sliding member can be attached and detached from the end of the arm very quickly and easily.

Furthermore, a cover (17) is provided to cover the gas spring (18), the rotating body (27), the transmission means (31), and the base of the arm (13) attached to the base plate (16), and the base plate (16) can be provided with a cover support part (16b) on which the upper end of the cover (17) is placed and supported, and a pair of left and right elastic locking protrusions (34a, 34b) that automatically engage with a pair of left and right engagement holes (33a, 33b) provided in the cover (17). With this configuration, not only are the gas spring and transmission means protected by the cover, but there is also no risk of the stored items getting caught on the gas spring or transmission means when inserting or removing them, which could adversely affect their operation. Moreover, the cover is simply placed over the base plate, the upper end of the cover is placed on the cover support part on the base plate, and the pair of left and right elastic locking protrusions on the base plate are automatically engaged with a pair of left and right engagement holes on the cover, so that the cover can be attached and detached extremely easily compared to an attachment structure using screws, etc.

FIG. 1 is a cross-sectional plan view illustrating the structure of a typical folding door. FIG. 2 is a cross-sectional plan view showing the main parts of a storage facility incorporating a door-opening biasing device according to the present invention. FIG. 3 is an elevational view of the main part of the storage facility of FIG. 2 as seen from the inside. 4A is a cross-sectional plan view showing the main part of FIG. 2, and FIG. 4B is a side view showing a vertical section of only the cover, showing the detailed structure of the door-opening biasing device according to the present invention. FIG. 5 is a plan view of the main part showing only the cover in FIG. 4 in a cross section taken along line XX. 6 is a front view showing only the cover in FIG. 4 in a cross-sectional view taken along line YY. FIG. 7 is a cross-sectional plan view of the main part of FIG. FIG. 8 is an enlarged vertical sectional side view of the lower end main portion of FIG. FIG. 9 is an enlarged plan view showing the tip of an arm provided in the door-opening biasing device according to the present invention. FIG. 10 is a partial cross-sectional plan view showing the tip of the arm shown in FIG. 9 and the sliding contact member before attachment. FIG. 11 is a vertical cross-sectional side view of FIG. FIG. 12 is a vertical cross-sectional side view of FIG.

Below, a preferred embodiment of the present invention will be described. Before that, the general structure of a folding door as an example to which the device of the present invention is applied will be described with reference to FIG. 1. The folding door 1 shown in FIG. 1 has two door bodies 5, 6 that open and close between side frames 3, 4 arranged on both the left and right sides of the opening for putting in and taking out stored items in the storage space 2. The two door bodies 5, 6 are connected to each other by a center hinge 7 at their adjacent inner sides so that they can be folded and unfolded freely. The outer side of one door body 5 is journaled on the inner surface of the side frame 3 by a side hinge 8 so that it can be opened and closed freely, and the outer side of the other door body 6 is supported by a slide hinge 9. The slide hinge 9 is supported by a slide rail 10 that is horizontally installed between the side frames 3, 4 and curves so that the area on the side frame 3 side moves away from the storage space 2 as it approaches the side frame 3.

The folding door 1 shown in FIG. 1 is a conventionally known type, so a detailed structural description will be omitted, but in the closed position where both door bodies 5 and 6 are unfolded into a single flat plate as shown by solid lines, the opening for inserting and removing stored items in the storage space 2 is fully closed, and in this state, the fully closed position where both door bodies 5 and 6 are unfolded into a single flat plate is maintained by the automatic locking mechanism of the center hinge 7. When opening the folding door 1, for example, by pulling the handle 11 attached to the outer surface near the inner edge of the door body 6 toward yourself and moving the door body 5 in the direction to open (away from the side frame 4), the door body 5 opens around the side hinge 8, and the outer edge of the door body 6 moves along the slide rail 10 together with the slide hinge 9, folding so that the inner edge of the door body 6 overlaps the inside of the door body 5 around the center hinge 7, and finally the folding door 1 changes to a fully open position as shown by virtual lines in FIG. 1.

When returning the folding door 1 from this fully open position to its original fully closed position, the handle 11 is used to move the door body 6 in the closing direction, and the door body 5 closes around the side hinge 8, and the outer edge of the door body 5 slides along the slide rail 10 together with the slide hinge 9 toward the side where the side frame 4 is located, causing the folding door 1 to return to its original fully closed position. As explained above, the folding door 1 that has returned to its fully closed position is held in that position by the automatic lock mechanism of the center hinge 7, so there is no risk of it opening unexpectedly.

For example, an embodiment in which the door opening biasing device of the present invention is incorporated into the folding door 1 shown in FIG. 1 is shown in FIG. 2 and FIG. 3. In the figure, 12 is the door opening biasing device of the present invention, which is vertically long and is attached to the lower end of the inner surface (the side where the storage space 2 is located) of the side frame 3 that supports the door body 5 with the side hinge 8 and adjacent to the inner surface of the door body 5 in the closed position, so that the length direction is vertically long. An arm 13 protrudes horizontally from the lower end side of the door opening biasing device 12. This arm 13 is biased to rotate horizontally toward the door body 5 by a mechanism built into the door opening biasing device 12 as described later. A sliding member 14 is attached to the tip of this arm 13, and a rectangular metal plate 15 that is long in the horizontal direction and is large enough to cover the entire sliding contact area is attached to the area where the sliding member 14 slides on the inner surface of the door body 5 by double-sided adhesive tape or the like.

The structure and operation of the door opening biasing device 12 will be explained in detail below with reference to Figures 4 to 8. The door opening biasing device 12 comprises a base plate 16 that is screwed to the inside surface of the side frame 3, and a cover 17 that covers the base plate 16 and the entire device. The base plate 16 is made of a vertically long, strip-shaped metal plate with multiple mounting holes 16a for screwing to the inside surface of the side frame 3, and at its upper end is a cover support portion 16b that is bent outward and connected, and at its lower end is a bearing support portion 16c that is bent horizontally outward and connected. Near the top end of the base plate 16, the upper end of a vertically long gas spring 18 is suspended by a horizontal support shaft 19, and a horizontal bevel gear 20 is rotatably supported by a horizontal support shaft 21 on the base plate 16 slightly below the bottom end of the gas spring 18. Furthermore, a vertical bevel gear 22 of the same diameter that meshes with the horizontal bevel gear 20 is rotatably supported by a vertical support shaft 23 on the bearing support portion 16c of the base plate 16.

8, a plate-shaped passive member 24 is fixed to the back surface of the horizontal bevel gear 20 by a plurality of screws 25, and the protruding eccentric portion 24a of this plate-shaped passive member 24, which protrudes diagonally upward outward from the peripheral surface of the horizontal bevel gear 20, is connected to the advance/retract moving portion 18a protruding from the lower end of the gas spring 18 by a horizontal support shaft 26 parallel to the horizontal support shaft 21 so as to be relatively rotatable. Also, a plate-shaped rotating body 27 is fixed to the back surface (lower surface) of the vertical bevel gear 22 by a plurality of screws 28, and the arm 13 shown in Figures 2 and 3 is integrally formed with the plate-shaped rotating body 27 so that the arm 13 extends horizontally from the plate-shaped rotating body 27. The small-diameter upper end of the vertical pin 29 is fitted and fixed to the eccentric position of the plate-shaped rotor 27, and the bearing support portion 16c of the base plate 16 has an arc-shaped guide slit 30 centered on the vertical support shaft 23 at the position where the lower end of the vertical pin 29 passes through, as shown in FIG. 7. As a result, the vertical shaft bevel gear 22 and the plate-shaped rotor 27, which rotate together, can only rotate within the range in which the vertical pin 29 can move within the guide slit 30, that is, within the arc-shaped angular range (a range slightly longer than 90 degrees) centered on the vertical support shaft 23 of the guide slit 30.

The horizontal bevel gear 20 and the vertical bevel gear 22 are structured to rotate in tandem at a 1:1 rotation ratio, so the horizontal bevel gear 20 also rotates forward and backward within a range slightly longer than 90 degrees. For this reason, as shown in Figures 5 and 6, the horizontal bevel gear 20 and the vertical bevel gear 22 are offset to one side (away from the door body 5) from the center position of the width of the base plate 16, so that the protruding eccentric portion 24a of the plate-shaped passive member 24 can rotate up and down within the space secured next to the horizontal bevel gear 20. In this embodiment, the transmission means 31 that converts the vertical movement of the retractable portion 18a protruding from the lower end of the gas spring 18 into the rotation of the rotating body (plate-shaped rotating body 27) to which the arm 13 is integrally extended is composed of a plate-shaped passive member 24 to which the retractable portion 18a is connected, a horizontal shaft bevel gear 20 that rotates integrally with the plate-shaped passive member 24, and a vertical shaft bevel gear 22 that rotates integrally with the plate-shaped rotating body 27, but the transmission means 31 is not limited to this configuration. For example, the transmission means 31 can be composed of a link mechanism without using gears.

The cover 17 covers the front side of the base plate 16 to which the gas spring 18, horizontal shaft bevel gear 20, and vertical shaft bevel gear 22 are attached. Only the back side of the base plate 16 is opened by the left and right side wall parts 17a, 17b, the front wall part 17c with a cross section of an arc shape connecting the left and right side wall parts 17a, 17b, the ceiling wall part 17d of the cover 17 is placed on the cover support part 16b at the upper end of the base plate 16, and the bottom wall part 17e is shaped to fit under the bearing support part 16c at the lower end of the base plate 16. When the cover 17 is moved horizontally from the front side of the base plate to cover the base plate 16 and the components of the door opening actuator 12 on the front side, the ceiling wall part 17d is placed and supported on the cover support part 16b at the upper end of the base plate 16, and a cover locking means 32 is provided to lock the cover 17 to the base plate 16 in this state.

The cover locking means 32 is composed of a pair of left and right engagement holes 33a, 33b provided at a position approaching the base plate 16 at the mid-height of the left and right side wall portions 17a, 17b of the cover 17, and a pair of left and right elastic locking protrusions 34a, 34b attached to the base plate 16. The pair of left and right elastic locking protrusions 34a, 34b are formed symmetrically on both ends of a horizontal strip-shaped metal plate 35 whose center is riveted to the base plate 16, and as shown in Figure 5, the dogleg-shaped protrusions of the locking protrusions 34a, 34b fit into the respective engagement holes 33a, 33b from the inside, providing the cover 17 with resistance to slipping out. In addition, when the cover 17 is attached to cover the front side of the base plate 16, the arm 13 extending forward from the plate-shaped rotating body 27 below the vertical shaft bevel gear 22 penetrates through a horizontal arc-shaped slit 36 that allows the arm 13 to swing horizontally. The horizontal arc-shaped slit 36 is provided from the arc-shaped front wall 17c of the cover 17 to the left and right side walls 17a and 17b. The actual horizontal swing range of the arm 13 is a range of just over 90 degrees from the center of the arc-shaped front wall 17c to the side of the door body that the door opening biasing device 12 is trying to open (in the above embodiment, the door body 5 on the left side when the folding door 1 is viewed from the front). Therefore, it is sufficient for the slit to have a length that can cover the horizontal swing range of the arm 13, but the horizontal arc-shaped slit is formed as in the above embodiment so that the same cover 17 can be used for the door opening biasing device 12 when the door body that the door opening biasing device 12 is trying to open is on the right side when viewed from the front.

A sliding member 14 is attached to the tip of the arm 13. If it is possible to ensure that the sliding member 14 attached to the tip of the arm 17 can be reliably passed through the horizontal arc-shaped slit 36 of the cover 17 when the cover 17 is attached, the cover 17 can be attached with the sliding member 14 attached to the tip of the arm 13, but in the illustrated embodiment, the vertical thickness of the sliding member 14 is slightly wider than the vertical width of the horizontal arc-shaped slit 36. Also, in consideration of the case where the arm 13 together with the sliding member 14 cannot be passed through the horizontal arc-shaped slit 36 without any problems due to the vertical position of the arm 13 being slightly offset in the vertical direction from the center position of the vertical width of the horizontal arc-shaped slit 36, it is preferable to attach the cover 17 to the base plate 16 with the sliding member 14 not attached to the arm 13, and to configure it so that the sliding member 14 can be attached to the tip of the arm 17 in a state where it protrudes outward from the horizontal arc-shaped slit 36 of the cover 17. This makes it convenient to configure the sliding contact member 14 to be easily attached and detached from the tip of the arm 13, so that it can be easily replaced if it becomes worn.

Taking the above into consideration, the embodiment of the present invention is configured so that the sliding member 14 can be easily attached and detached to the tip of the arm 13. The specific structure is described with reference to Figures 9 to 12. A circular through hole 37 that penetrates in the thickness direction (vertical direction) of the plate is provided in the area where the sliding member 14 fits at the tip of the thick plate arm 13, and a recess 38 is provided in one end of the plastic sliding member 14 in the longitudinal direction into which the tip of the arm 14 is inserted. The upper and lower flat plate portions 14a, 14b of the recessed portion 38, which sandwich the arm 14 inserted into the recessed portion 38 from above and below, have elongated hole-shaped openings 38a, 38b that are long in the length direction of the sliding member 14, formed at the same position in the vertical direction. One of the elongated hole-shaped openings 38a is integrally molded with an elastic tongue portion 39 that extends from the tip end of the sliding member 14 of the elongated hole-shaped opening 38a (the end where the recessed portion 38 is closed) toward the opposite end of the elongated hole-shaped opening 38a, and an engagement protrusion 40 that protrudes into the recessed portion 38 is integrally molded on the inside of the free end of the elastic tongue portion 39. This engagement protrusion 40 is circular so that it can fit exactly into the circular through hole 37 provided in the arm 13, and the circular end surface of the area slightly more than half the area on the entrance side of the recessed portion 38 is an inclined surface 40a that gradually decreases in height until the protruding height of the engagement protrusion 40 becomes zero as it approaches the entrance side of the recessed portion 38.

With the sliding member 14 configured as described above, when the tip of the arm 13 is inserted into the recessed portion 38 of the sliding member 14 so that the upper and lower flat portions 14a, 14b of the recessed portion 38 sandwich both side surfaces where the circular through hole 37 at the tip of the arm 13 opens, during the insertion process, the arm 13 pushes the engagement protrusion 40 on the sliding member 14 side outward from the recessed portion 38 via its inclined surface 40a, and as a result, the elastic tongue portion 39 equipped with the engagement protrusion 40 bends outward against its elasticity, allowing the tip of the arm 13 to enter completely into the recessed portion 38 of the sliding member 14. When the tip of the arm 13 is completely inserted into the recess 38 of the sliding member 14, the engagement protrusion 40 reaches a position where it overlaps with the circular through hole 37 provided at the tip of the arm 13, and the elastic tongue portion 39, which has been bent outward against elasticity, returns to its original position, causing the engagement protrusion 40 to fit into the circular through hole 37 on the arm 13 side. In this state, even if you try to remove the sliding member 14 from the arm 13, it is impossible to remove the sliding member 14 because the cylindrical region of the engagement protrusion 40 is in contact with the cylindrical circumferential surface of the circular through hole 37 on the arm 13 side.

When it becomes necessary to replace the sliding member 14, the circular through hole 37 of the arm 13 is located in the long hole opening 38b on the side of the sliding member 14 that does not have the elastic tongue portion 39, so a force is applied to the flat end surface of the engagement protrusion 40 that fits into the circular through hole 37 of the arm 13 from this long hole opening 38b to the opposite side with a suitable rod-shaped body. As a result, as the elastic tongue portion 39 curves outward against the elasticity, the engagement protrusion 40 moves so as to come out of the circular through hole 37 of the arm 13. When the engagement protrusion 40 comes out of the circular through hole 37 of the arm 13, the sliding member 14 can be removed from the arm 13 by pulling it out from the tip of the arm 13.

In the configuration according to the above embodiment, the horizontal support shaft 19 for suspending the gas spring and the horizontal support shaft 21 for supporting the horizontal shaft bevel gear attached to the base plate 16 have large-diameter base shaft portions 19a, 21a integral with the horizontal support shafts 19, 21, respectively, as shown in FIG. 4B, and these large-diameter base shaft portions 19a, 21a are welded and fixed to the base plate 16. In this case, it is preferable to integrally form a small-diameter shaft portion at the mounting end of each base shaft portion 19a, 21a so that the welding position of the large-diameter base shaft portions 19a, 21a is determined, and to weld the base shaft portions 19a, 21a to the base plate 16 with this small-diameter shaft portion fitted into a through hole provided in the base plate 16. The vertical support shaft 23 that supports the vertical shaft bevel gear 22 is attached by inserting the small diameter shaft portion 23a at the lower end into a through hole provided in the bearing support portion 16c of the base plate 16 and crimping it, but instead of crimping, it is also possible to screw the vertical support shaft 23 from the underside of the bearing support portion 16c.

In addition, the cover 17 is made of molded plastic, and the pair of left and right engagement holes 33a, 33b are formed by molding as follows, so that subsequent drilling processes are not required. That is, as shown in FIG. 4B and FIG. 5, a horizontal linear groove 41 is formed from the position of the engagement holes 33a, 33b to the arc-shaped front wall 17c of the cover 17, and the bottom plate 41a forming this groove 41 is set to a position just before the engagement holes 33a, 33b. A protrusion that forms the groove 41 with a length including the engagement holes 33a, 33b is provided on the outer mold that forms the cover 17, and a recess that forms the groove 41 is provided on the inner mold that forms the cover 17 at a position corresponding to the engagement holes 33a, 33b. By doing so, the outer mold that forms the cover 17 is pulled out to the side where the arc-shaped front wall of the cover 17 is located, and the inner mold that forms the cover 17 is pulled out to the opposite side of the outer mold, and thus the cover 17 with the engagement holes 33a, 33b can be plastic molded.

In the door opening biasing device 12 of the present invention configured as described above, the downward biasing force acting on the advance/retract movement portion 18a of the gas spring 18 acts on the horizontal shaft bevel gear 20 via the plate-shaped passive member 24, and tries to rotate the horizontal shaft bevel gear 20 around the horizontal support shaft 21. The horizontal shaft bevel gear 20 tries to rotate counterclockwise in FIG. 6 because the protruding eccentric portion 24a of the plate-shaped passive member 24 integral with the horizontal shaft bevel gear 20 is pushed down counterclockwise in FIG. 6. Therefore, the vertical shaft bevel gear 22 meshing with the horizontal shaft bevel gear 20 receives a clockwise rotational force in FIG. 5, and the arm 13 connected to the plate-shaped rotating body 27 integral with the vertical shaft bevel gear 22 receives the same clockwise rotational force as the vertical shaft bevel gear 22. As a result, as shown in FIG. 2, the sliding member 14 at the tip of the arm 13 is pressed against the surface of the metal plate 15 attached to the inside surface of the door body 5 journaled on the side frame 3. At this time, if both door bodies 5, 6 of the folding door 1 are in a fully closed state, unfolded into a single flat plate, and locked in this state by the locking mechanism of the center hinge 7, the sliding member 14 at the tip of the arm 13 is simply pressed against the surface of the metal plate 15 on the inside surface of the door body 5, and does not open the door body 5. In other words, the biasing force of the gas spring 18 is set so that a large opening force that would release the locking action of the locking mechanism of the center hinge 7 is not applied to the door body 5.

The states shown in each of Figures 4B to 8 are shown in a virtual state in which the arm 13 protrudes perpendicularly to the base plate 16. In this virtual state, as shown in Figure 7, the vertical pin 29 of the plate-shaped rotating body 27 integral with the arm 13 is located at one end of the arc-shaped guide slit 30, but as shown in Figures 2 and 4A, when the door opening biasing device 12 is in use with the folding door 1 incorporated and the door body 5 to be opened is locked in the closed position, the arm 13, which is attempting to rotate clockwise by the biasing force of the guide slit 30 as described above, rotates slightly from the virtual state toward the door body 5, and the sliding member 14 at the tip of the arm 13 is pressed against the surface of the metal plate 15 on the inside surface of the door body 5.

When the lock of the folding door 1 in the fully closed state is manually released from the above state as described above and the door is opened, the door body 5 is pushed from the inside by the arm 13 (the sliding contact member 14 at the tip) by the clockwise opening force (the biasing force of the gas spring 18) acting on the arm 13 shown in Figure 2, and the folding door 1 is opened. When the door body 5 opens to the opening limit position where it extends almost perpendicularly in front of the side frame 3 as shown by the imaginary line in Figure 2, the folding door 1 is in a fully open state with both door bodies 5, 6 folded. The rotation angle of the arm 13 at this time, that is, the rotation angle from the arm 13 when the door body 5 is in the closed position shown by the solid line in Figure 2 to the arm 13 when the door body 5 is opened to the opening limit position shown by the imaginary line, is approximately 90 degrees, and is approximately 95 degrees from the imaginary position of the arm 13 in the imaginary state shown in each of Figures 4B to 8. Therefore, the angular range of the arc-shaped guide slit 30 that restricts the rotation range of the arm 13 via the vertical pin 29 on the arm 13 side shown in FIG. 7 is set to about 100 degrees, allowing for a margin of opening angle up to the open limit position of the door body 5.

As is clear from the above description, by using the door opening biasing device 12 of the present invention as the opening means for the door body 5, the door body 5 can be automatically opened to the open limit position by the biasing force of the gas spring 18 as long as the lock at the closed position is released. In the above embodiment, the door opening biasing device 12 of the present invention is used as the opening means for the door body 5 whose outer edge is supported by the side hinge 8 on the side frame 3 of the folding door 1, but it can also be used for a folding door in which the door body 6 is supported by the side hinge 8 on the side frame 4 with the door bodies 5 and 6 of the folding door 1 reversed in configuration. In this case, the door opening biasing device 12 is attached to the inside of the side frame 4, and the arm 13 biases the door body 6 in the opening direction. In addition, it can be used not only for folding doors, but also for general single doors that can be opened and closed freely. Also, with regard to the locking mechanism that locks the door in the closed position, in addition to locking mechanisms that are unlocked by simply pulling the door in the direction that forces it open, there are also locking mechanisms that are unlocked by manually pushing the side of the door opposite the side that is pivoted on the side frame (the side with the center hinge in the case of a folding door).

The virtual states shown in Figures 4B to 8 are not necessary in actual use, but if the arm 13 can be temporarily locked in this virtual state, that is, when the arm 13 protrudes perpendicularly from the base plate 16 in a plan view, the arm 13 can be prevented from rotating in the door opening direction by the biasing force of the gas spring 18 while the door opening biasing device 12 is being installed in the application location, making installation easier. A simple method for temporarily locking the arm 13 in the virtual state can be to insert a rod-shaped object such as a bolt or pin between a vertical through hole in the arm 13 and a through hole in the bearing support part 16c of the base plate 16.

The door opening biasing device of the present invention can be used as a means of improving various existing doors, whose sides are supported by hinges on a side frame so that they can be opened and closed freely, and which are locked in the closed position, so that they can be opened automatically simply by releasing the lock.

REFERENCE SIGNS LIST 1 Folding door 2 Storage space 3, 4 Side frame 5, 6 Door body 7 Center hinge 8 Side hinge 9 Slide hinge 10 Slide rail 11 Handle 12 Door opening biasing device 13 Arm 14 Sliding contact member 14a, 14b Upper and lower flat plate portions 15 Metal plate 16 Base plate 16a Mounting hole 16b Cover support portion 16c Bearing support portion 17 Cover 17a, 17b Left and right side wall portions 17c Arc-shaped front wall portion 17d Ceiling wall portion 17e Bottom wall portion 18 Gas spring 18a Inward/outward moving portion 19, 21, 26 Horizontal support shaft 19a, 21a Large diameter base shaft portion 20 Horizontal shaft bevel gear 22 Vertical shaft bevel gear 23 Vertical support shaft 23a Small diameter shaft portion 24 Plate-shaped passive member 24a Protruding eccentric portion 25, 28 Screw 27 Plate-shaped rotating body 29 Vertical pin 30 Guide slit 31 Transmission means 32 Cover locking means 33a, 33b Pair of left and right engagement holes 34a, 34b Pair of left and right elastic locking protrusions 35 Band-shaped metal plate 36 Horizontal arc-shaped slit 37 Circular through hole 38 Recessed portion 38a, 38b Slot-shaped opening 39 Elastic tongue portion 40 Engagement protrusion 40a Inclined surface 41 Recessed groove portion 41a Bottom plate portion

Claims (5)

A door opening biasing device attached to a side frame on which a door body is supported so as to be freely opened and closed, the device comprises a vertically long base plate attached to a position inside the side frame close to the door body, a vertically long gas spring with one end attached to the upper end of the base plate and hanging down, a rotor supported on the lower end of the base plate for rotation around a vertical axis, a transmission means for converting the vertical movement of the extension/retraction moving part protruding from the lower end of the gas spring into rotation of the rotor, and an arm extending horizontally from the rotor in a direction away from the side frame, the device being configured such that the tip of the arm is pressed against the inner surface of the door body by the downward moving force of the extension/retraction moving part of the gas spring, biasing the door body in the opening direction. The door opening biasing device according to claim 1, wherein the transmission means is composed of a vertical bevel gear that rotates integrally with the rotor, a horizontal bevel gear that is supported by a horizontal support shaft on the base plate and engages with the bevel gear, and a passive member that rotates integrally with the horizontal bevel gear around the horizontal support shaft and to which the advancing and retracting moving part of the gas spring is axially supported at an eccentric position, and the downward movement of the advancing and retracting moving part of the gas spring is transmitted to the rotor via the horizontal bevel gear and the vertical bevel gear. The door opening biasing device according to claim 1 or 2, in which a plate of a size covering the sliding contact area of the tip of the arm is attached to the inner surface of the door body against which the tip of the arm is pressed, and a sliding member that slides against the plate is attached to the tip of the arm. The door opening biasing device according to claim 3, wherein the tip of the arm is provided with a through hole penetrating the arm in the thickness direction, the sliding contact member has a recessed portion into which the tip of the arm is inserted, openings provided on both sides of the recessed portion so as to be adjacent to both sides of the arm in the thickness direction within the recessed portion, a cantilevered elastic tongue portion connected to the periphery of one of the openings, and an engagement protrusion is provided on the tip of the elastic tongue portion so as to automatically fit into the through hole when the tip of the arm is inserted into the recessed portion, and the engagement protrusion that fits into the through hole can be pushed out of the through hole against the elasticity of the elastic tongue portion from the other opening. 2. The door opening biasing device according to claim 1, further comprising a cover for concealing the gas spring, the rotating body, the transmission means and the base of the arm which are attached to the base plate, and the base plate is provided with a cover support portion on which the upper end of the cover is placed and supported, and a pair of left and right elastic locking protrusions which automatically engage with a pair of left and right engagement holes provided in the cover.

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