JP7464983B2 - Door closing assistance device - Google Patents

Description

The present invention relates to a door closing assistance device that assists in the closing operation of a pivoting door installed at the entrance or exit of a building or room by pulling the door toward the door frame during the closing process.

In recent years, door closers that can slowly and automatically close open doors have been increasingly installed on pivoting (hinge-type) doors that open and close openings such as entrances and exits of buildings and rooms. A commonly known door closer connects the upper stile of the door frame to the top end of the door with a connecting arm, and controls the opening and closing of the door by using a spring and hydraulic pressure. However, when such a door closer is installed, the door often feels heavy to open and close, and the hinges that support the door are constantly under load, which can cause problems such as abnormal noises from the hinge attachment area when the door is opened or closed, or damage to the hinges.

In response to this, Patent Document 1 and other documents propose a door closing assistance device that consists of a device body that is attached to one of the door frames and the door that is rotatably mounted on the door frame, and a trigger that is attached to the other, and when the door is closed, the retractable arm of the device body that engages with the trigger rotates during the process, thereby drawing the door to the door frame.

Specifically, in most door closing assistance devices, the retractable arm of the device body is supported on the device body case so that it can rotate between a standby position corresponding to the open state of the door and a retracted position corresponding to the closed state of the door, and when the door is open and the retractable arm is not engaged with the trigger, the retractable arm is held in the standby position by the biasing force received from the biasing mechanism, and when the door is closed, the trigger that engaged with the retractable arm during the process releases the retractable arm from its standby position, causing the biasing mechanism to bias the retractable arm in the direction of rotation to the retracted position, and the retractable arm rotates while being braked by the brake mechanism in the engaged state with the trigger, drawing the door to the door frame.

Unlike the door closer described above, the door closing assistance device configured as above does not have a connecting arm that connects the door frame and the door, and is designed to control the movement of the door only in the area where the door is relatively close to the closed position. Therefore, if an open door is manually closed to a certain extent, the door can be closed slowly and automatically from that point on, just like a door closer, and since it does not control the entire opening and closing operation of the door, it can be opened and closed relatively easily. In addition, since there is little strain on the hinges, strange noises and damage to the hinges are less likely to occur when the door is opened and closed.

JP 2010-95979 A

In the door closing assistance device of Patent Document 1, the contact portion of the urging mechanism with the retractable arm is formed in a mountain shape that protrudes toward the retractable arm, and when the retractable arm is held in the standby position, the pressure-receiving roller of the retractable arm contacts the rear inclined surface of the contact portion of the urging mechanism, and when the retractable arm engaged with the trigger rotates slightly as the door is closed, and the pressure-receiving roller overcomes the top of the contact portion of the urging mechanism, the retractable arm is released from the standby position and the retractable arm rotates in the direction of retracting the trigger into the device body (retraction direction) due to the urging force of the urging mechanism. In other words, the contact portion of the urging mechanism is formed so that the apex of the contact portion is located at the pivot point relative to the rotation center of the retractable arm.

However, when the pressure roller of the retractable arm held in the standby position overcomes the top of the contact part of the biasing mechanism, i.e., the biasing point, the pressure roller must move the contact part in a direction away from the retractable arm against the biasing force of the biasing mechanism. Therefore, if the force applied to the door by hand in the closing direction when attempting to close the door is small, even if the trigger engages with the retractable arm, the pressure roller of the retractable arm may not overcome the biasing point of the biasing mechanism, and the door may not be able to close.

The present invention aims to provide a door closing assistance device that assists in the closing of a door by engaging a retractable arm of the device body attached to one side of the door frame and a pivoting door with a trigger attached to the other side, thereby making the door closing assistance operation more reliable.

In order to solve the above problems, the present invention comprises a device body attached to one of a door frame and a door provided rotatably relative to the door frame, and a trigger attached to the other, the device body being provided with a main body case, a retractable arm that is rotatably supported on the main body case between a standby position corresponding to the open state of the door and a retracted position corresponding to the closed state of the door and that can engage with the trigger, a biasing mechanism that biases the retractable arm within the rotation plane, and a braking mechanism that brakes the rotation of the retractable arm from the standby position to the retracted position, and when the door is in an open state and the retractable arm of the device body is not engaged with the trigger, the retractable arm is held in the standby position by the biasing force received from the biasing mechanism, and when the door is closed, the trigger that engaged with the retractable arm in the process releases the holding of the retractable arm in the standby position, thereby preventing the retractable arm from being held in the standby position by the biasing force received from the biasing mechanism. In a door closing assistance device in which a biasing mechanism biases the retractable arm in a direction to rotate to the retracted position, and the retractable arm rotates while being braked by the brake mechanism in a state where it is engaged with a trigger, thereby drawing the door to the door frame, when the trigger engages with the retractable arm in the process of closing the door, the contact point of the retractable arm with the biasing mechanism overcomes the biasing point of the biasing mechanism relative to the rotation center of the retractable arm, thereby releasing the holding of the retractable arm in the standby position, and the abutment portion of the biasing mechanism that abuts against the retractable arm has an arm holding surface that is perpendicular to the biasing direction of the biasing mechanism, and an inclined surface that is continuous with the arm holding surface and inclined in a direction away from the rotation center of the retractable arm, and is configured so that the arm holding surface abuts against the retractable arm in the standby position, and the biasing point is located halfway along the inclined surface.

According to the above configuration, when the trigger engages with the retractable arm in the standby position during the process of closing the door, slightly rotating the retractable arm, the contact point of the retractable arm with the biasing mechanism moves from the arm holding surface of the abutment part of the biasing mechanism to an inclined surface where the resistance to the rotation of the retractable arm is small, and since the biasing point of the biasing mechanism is located halfway on that inclined surface, the contact point of the retractable arm easily overcomes the biasing point of the biasing mechanism. Therefore, even if the force applied to the door in the closing direction when attempting to close the door is small, when the trigger engages with the retractable arm, the contact point of the retractable arm reliably overcomes the biasing point of the biasing mechanism and the retractable arm rotates in the retracting direction, assisting the door closing operation.

The braking mechanism may also include a linear damper that is held axially movable, and a buffer spring that brakes the axial movement of the damper that is pressed by the retractable arm during the process of closing the door.

In this way, when the retractable arm engaged with the trigger begins to rotate during the process of closing the door, there is almost no braking action by the damper, and the axial movement of the damper pressed by the retractable arm is braked by the buffer spring. This also reduces the rotational resistance of the retractable arm, making it easier for the contact point of the retractable arm to overcome the biasing point of the biasing mechanism, so that the door closing assistance operation can be performed more reliably.

As described above, the door closing assistance device of the present invention is designed to make it easier for the contact point between the retractable arm and the biasing mechanism to overcome the biasing mechanism's biasing point when the trigger engages with the retractable arm in the standby position during the process of closing the door. Therefore, even if the force applied to the door in the closing direction when attempting to close the door is small, the retractable arm can reliably rotate in the retracting direction to perform the door closing assistance operation.

FIG. 2 is a perspective view showing an installation state of the door closing assistance device according to the embodiment; FIG. 2 is a cross-sectional plan view of the door closing assist device of FIG. 1 (when the door is being closed); FIG. 2 is an exploded perspective view of the main body of the device shown in FIG. FIG. 4A is a perspective view of the retractable arm in an assembled state in FIG. 3, and FIG. 4B is a cross-sectional view taken along line IV-IV in FIG. FIG. 3 is an enlarged cross-sectional plan view showing a main part of the main body of the device shown in FIG. FIG. 6 is a cross-sectional plan view showing a state in which the retractable arm is rotated in the retracting direction corresponding to FIG. 5 . FIG. 3 is a cross-sectional plan view showing a state of the door closing assist device when the door is closed, corresponding to FIG. FIG. 3 is a cross-sectional plan view illustrating a method for adjusting the pressing force of the arm pressing spring of FIG. FIG. 9 is a perspective view from below showing the operation of adjusting the pressing force of the arm pressing spring in FIG. 8 . 1A and 1B are explanatory diagrams of the operation when the door is closed when the retractable arm is in the retracted position, respectively.

Below, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, this door closing assistance device is installed on a hinged door D that opens and closes the entrance to a room in a house, and is composed of a device main body 1 attached to the upper frame of a door frame F provided around the periphery of the entrance, and a trigger 31 attached to the upper end of the door D that is rotatably provided via a hinge (not shown) on one vertical frame of the door frame F. The door frame F has a portion without a door stop S at the upper corner opposite the hinge, and the device main body 1 is attached to this portion. In the following description, the side of the device main body 1 facing the other vertical frame of the door frame F is referred to as one end side, and the opposite side is referred to as the other end side.

As shown in Figures 2 and 3, the device main body 1 includes a horizontally long main body case 2 consisting of a metallic upper case 2a and lower case 2b, a retractable arm 3 that is rotatably supported by the main body case 2 and can engage with a trigger 31 as described below, a biasing mechanism 4 that biases the retractable arm 3 within its rotational plane, and a braking mechanism 5 that brakes the rotation of the retractable arm 3.

The main case 2 is integrated with the upper case 2a and the lower case 2b by a plurality of case fixing screws 6, with each part such as the retractable arm 3, the biasing mechanism 4, and the braking mechanism 5 built in. The main case 2 is attached to the lower surface of the upper frame of the door frame F by a plurality of case mounting screws 7 (not shown in FIG. 3) that penetrate the entire case, with the longitudinal direction parallel to the upper frame of the door frame F and the retractable arm 3 protruding from the opening on the front side (the surface facing the closed door D). The case fixing screws 6 are screwed into a cylindrical casing spacer 8 fixed to the lower case 2b from the upper surface side of the upper case 2a, and the case mounting screws 7 are screwed into the upper frame of the door frame F while passing through a cylindrical mounting screw spacer 9 arranged between the upper and lower cases 2a and 2b. In addition, a notch that is continuous with the front opening is formed on the underside of the main case 2 in the same shape as the top, so that when closing the door D as described below, the retractable arm 3 can retract part of the trigger 31 to the bottom of the main case 2 without interfering with the main case 2.

As shown in Figures 4(a) and (b), the retractable arm 3 is made up of an arm body 10 whose base end is rotatably supported by the main body case 2 and whose tip engages with a trigger 31, a slide piece 11 that is triangular in plan view and attached to the tip of the arm body 10, and a slide piece pressure spring 12 that biases the slide piece 11 toward the base end of the arm body 10. The arm body 10 and slide piece 11 are made of resin.

At the tip end of the arm body 10, a slide piece guide portion 10a is provided on one side in the width direction, which is a roughly trapezoidal flat plate in a plan view and guides the movement of the slide piece 11 along the arm body 10. In addition, the slide piece guide portion 10a is provided with a spring pocket 10b that extends in the longitudinal direction of the arm body 10 and accommodates the slide piece pressure spring 12.

The slide piece 11 has a triangular slit 11a in plan view that opens on the side facing the center of the width direction of the arm body 10 and the side facing the base end, into which a part of the slide piece guide part 10a is inserted, and a spring holding hole 11b that extends from the side facing the tip side of the arm body 10 (slit closing surface) to a position overlapping with the spring pocket 10b. When assembling this slide piece 11 to the arm body 10, after placing the slide piece pressing spring 12 in the spring pocket 10b of the arm body 10, the slide piece 11 can be pushed in while being elastically deformed from the position where the slit 11a faces the slide piece guide part 10a on the side of the arm body 10 until the slide piece pressing spring 12 is held by the spring holding hole 11b.

The slide piece 11 attached to the arm body 10 is biased toward the base end of the arm body 10 by the slide piece pressure spring 12 pressing against the bottom surface of the spring holding hole 11b, and the wall of the slit closing surface abuts against the slide piece guide portion 10a, restricting movement toward the base end of the arm body 10. As a result, when the slide piece 11 receives a force in a direction that compresses the slide piece pressure spring 12, it is guided by the slide piece pressure spring 12 and the slide piece guide portion 10a and slides toward the tip side of the arm body 10 (see Figures 10(a) and (b)).

By assembling this slide piece 11, an engagement groove 3a for engaging with a trigger 31, as described below, is formed on the underside of the tip end portion of the arm body 10 of the retractable arm 3. The engagement groove 3a has a straight section that opens at one end at the tip of the retractable arm 3 and extends in the longitudinal direction, and an introduction section that opens from the other end of the straight section to the front side of the retractable arm 3.

On the other hand, the base end portion of the arm body 10 is provided with a pair of upper and lower pivot shaft parts 10c that are rotatably inserted into the pivot shaft hole 2c of the main body case 2, pressure receiving parts 10d that support both ends of the pressure receiving pin 13 arranged in the vertical direction, and connecting parts 10e that support both ends of the connecting pin 14 also arranged in the vertical direction.

The rotation of the arm body 10 around the pivot shaft 10c is restricted by a stopper 2d protruding inward from the top and bottom surfaces of the body case 2 and a casing spacer 8 near one end (the left end in FIG. 2) of the body case 2, and the retractable arm 3 can rotate between a standby position corresponding to the open state of the door D and a retracted position corresponding to the closed state of the door D. The stopper 2d abuts on the same side as the tip side that extends long from the center of rotation of the arm body 10 to prevent the arm body 10 from bending. An annular groove is formed around the pivot shaft 10c, and an inward annular protrusion formed by burring the periphery of the pivot shaft hole 2c fits into this annular groove, and a lubricant (not shown) is held, allowing the retractable arm 3 to rotate stably.

The pressure-receiving portion 10d of the arm body 10 receives a pressing force from the biasing mechanism 4 via a pressure-receiving pin 13 and a pressure-receiving roller 15 slidably fitted into the axial center of the pin. The connecting portion 10e is connected to the braking mechanism 5 by an oval-shaped joint fitting 16 that has a connecting pin 14 and its axial center passed through a hole on one side.

The biasing mechanism 4 comprises an arm pressure spring 17 arranged along the longitudinal direction of the main body case 2 (generating a biasing force along the longitudinal direction), a first spring case 18 and a second spring case 19 that respectively hold both ends of the arm pressure spring 17, and a cam member 20 that abuts against the second spring case 19 on the side opposite the arm pressure spring 17. The arm pressure spring 17 presses against a pressure roller 15 attached to the retractable arm 3 via the first spring case 18, thereby biasing the retractable arm 3 within its rotational plane.

The first spring case 18 has one end of the arm pressure spring 17 inserted into a spring insertion hole 18a provided on the surface facing the second spring case 19, and the pressure surface 18b provided on the opposite side abuts against the pressure roller 15 of the retractable arm 3. On the other hand, the second spring case 19 has the other end of the arm pressure spring 17 inserted into a spring insertion hole 19a provided on the surface facing the first spring case 18, and the inclined cam surface 19b provided on the opposite side abuts against the cam member 20. The inclined cam surface 19b of the second spring case 19 is formed so as to be inclined with respect to the longitudinal direction of the main body case 2 in a plan view. In addition, the band-shaped protrusions 18c, 19c formed on the upper and lower surfaces of each of the spring cases 18, 19 are slidably fitted into the upper and lower guide grooves 2e1, 2e2 extending in the longitudinal direction of the main body case 2, respectively.

The cam member 20 has an inclined cam surface 20a that slides parallel to the inclined cam surface 19b of the second spring case 19, and the rectangular plate-shaped protrusions 20b formed on the upper and lower surfaces are slidably fitted into the upper and lower guide grooves 2f that extend in the width direction of the main body case 2. A spring adjustment screw 21 that penetrates the cam member 20 in the front-rear direction (width direction of the main body case 2) is screwed into an adjustment nut 22 that is non-rotatably housed in a hollow portion that opens into the surface of the cam member 20 opposite the inclined cam surface 20a. The spring adjustment screw 21 is housed in the main body case 2 with its tip abutting the outer peripheral surface of the above-mentioned mounting screw spacer 9 located near the other end of the device main body 1, and its head passing through the short side of the screw holder 23 that is L-shaped in plan view, and can be rotated from the outside of the main body case 2 in the width direction through a hole opened in the front of the main body case 2.

The braking mechanism 5 includes a linear damper 24 arranged along the longitudinal direction of the main body case 2, a damper holder 25 that holds the tubular portion 24a of the damper 24 so that it can move in the axial direction, a damper cap 26 that is U-shaped in side view and engages with the tip of the shaft portion 24b of the damper 24, and a buffer spring 27 that is arranged between the bottom surface of the tubular portion 24a of the damper 24 and the damper holder 25, and the damper 24 brakes the rotation of the retractable arm 3 via the damper cap 26 and the joint metal fitting 16. The damper 24 is adjusted so that the resistance when the shaft portion 24b is retracted into the tubular portion 24a is approximately the same as the resistance when it is protruding.

The damper holder 25 consists of a base end 25a through which the mounting screw spacer 9 passes, and upper and lower arms 25b that extend from the base end 25a in parallel to the damper 24 and clamp the tubular portion 24a of the damper 24. The base end 25a has a hole in the side wall that faces the cam member 20 described above for abutting the tip of the spring adjustment screw 21 against the mounting screw spacer 9. The projections 25c formed on the top surface of the upper arm 25b and the bottom surface of the lower arm 25b fit into the positioning holes 2g of the main body case 2, so that the entire damper holder 25 is positioned.

The damper cap 26 has an engagement hole 26a into which the tip of the shaft 24b of the damper 24 is inserted. In addition, multiple protrusions 26b formed on the upper and lower surfaces are slidably fitted into upper and lower guide grooves 2h extending in the longitudinal direction of the main body case 2. A connecting pin 28 passes through the upper and lower arms of the U-shape, and the axial center of this connecting pin 28 passes through the hole on the other side of the joint fitting 16 mentioned above, thereby connecting the damper cap 26 to the retractable arm 3. Note that both ends of the connecting pin 28 protruding between the protrusions 26b from the upper and lower surfaces of the damper cap 26 are formed with a small diameter so as to fit into the guide groove 2h of the main body case 2.

The main body 1 of this door closing assistance device has the above-mentioned configuration, and as shown in Figures 1 and 2, one end face of the main body case 2 faces the upper end of the other vertical frame of the door frame F with a small gap between them, and the retractable arm 3 is attached to the upper frame of the door frame F in a position in which it projects toward the door D.

On the other hand, as shown in Figures 1 and 2, the trigger 31 has a cover 32 and a trigger shaft 33 protruding from the top surface of the cover 32, and is attached to the upper end of the door D opposite the hinge so that the trigger shaft 33 engages with an engagement groove 3a formed in the retractable arm 3 of the device main body 1 when the door D is in an area somewhat close to its closed position.

Next, the operation of this door closing assistance device will be described. First, as shown in FIG. 1, when the door D is open and the retractable arm 3 of the device body 1 is not engaged with the trigger 31, the retractable arm 3 is held in the standby position (pulled out from the main body case 2). The reason why the retractable arm 3 is held in this manner is that, as shown in FIG. 5, the pressure roller 15 of the retractable arm 3 and the pressing surface 18b of the first spring case 18 of the biasing mechanism 4 come into contact with each other above the line A (a line extending from the rotation center O parallel to the biasing direction of the arm pressing spring 17) which is a set of the thinking points of the biasing mechanism 4 relative to the rotation center O of the retractable arm 3, and a counterclockwise moment is applied to the retractable arm 3 by the biasing force from the biasing mechanism 4, and the counterclockwise rotation is restricted by the stopper 2d of the main body case 2 (see FIG. 2).

Then, when the open door D is rotated in the closing direction, in the process, as shown in FIG. 2, the trigger shaft 33 of the trigger 31 comes into contact with the tip of the retractable arm 3 of the device body 1 (part of it enters the straight portion of the engagement groove 3a). At this time, the tip of the retractable arm 3 is pressed by the trigger shaft 33 and rotates slightly clockwise, and the contact point between the pressure-receiving roller 15 of the retractable arm 3 and the first spring case 18 of the biasing mechanism 4 overcomes the biasing point (straight line A) of the biasing mechanism 4.

Then, the retractable arm 3 is released from the standby position, and as shown in FIG. 6, the first spring case 18 moves toward one end of the device body 1 due to the biasing force of the arm pressing spring 17 of the biasing mechanism 4, and at the same time, the retractable arm 3 rotates clockwise (in the retracting direction). As a result, the trigger shaft 33 moves (is retracted) relatively toward the back of the straight portion of the engagement groove 3a of the retractable arm 3, and the door D automatically rotates around the hinge together with the trigger 31 and is drawn toward the door frame F. After that, as shown in FIG. 7, the retractable arm 3 abuts against the casing spacer 8 at the retracted position inside the main case 2 and stops, and the door D also stops in the closed position.

Here, the rotation of the retractable arm 3 from the standby position to the retracted position is braked by the action of the brake mechanism 5 connected to the connecting part 10e of the retractable arm 3. That is, when the retractable arm 3 rotates clockwise from the standby position, the connecting part 10e of the retractable arm 3 presses the damper cap 26 of the brake mechanism 5 and the shaft part 24b of the damper 24 via the connecting pin 14 and the joint metal fitting 16, so that the rotation of the retractable arm 3 is decelerated by the resistance to the sinking of the shaft part 24b of the damper 24 into the tube part 24a. As a result, even if a strong force is applied to the door D in the closing direction by hand, etc., the door D closes slowly and does not generate an impact sound when it hits the door stop S of the door frame F.

Furthermore, with this door closing assistance device, the mechanism described below ensures that even if the force applied to the door D in the closing direction is small, the retractable arm 3 will rotate reliably in the retracting direction when the trigger shaft 33 comes into contact with the tip of the retractable arm 3.

5, the pressing surface 18b of the first spring case 18, which is the contact portion between the retractable arm 3 and the biasing mechanism 4, is composed of an arm holding surface 18b1 perpendicular to the biasing direction of the biasing mechanism 4, and an inclined surface 18b2 that is continuous with the arm holding surface 18b1 and inclined in a direction away from the rotation center O of the retractable arm 3. The arm holding surface 18b1 contacts the pressure-receiving roller 15 of the retractable arm 3 in the standby position, and the biasing mechanism 4 is formed so that the point of consideration (straight line A) is located midway along the inclined surface 18b2. Therefore, when the trigger 31 contacts the retractable arm 3 in the standby position during the process of closing the door D and rotates the retractable arm 3 slightly, the pressure-receiving roller 15 immediately comes into contact with the inclined surface 18b2 of the first spring case 18, and the resistance to the rotation of the retractable arm 3 is reduced. This makes it easier for the contact point between the pressure roller 15 and the first spring case 18 to overcome the contact point (straight line A) compared to when the contact surface with the retractable arm of the biasing mechanism is formed only from a surface perpendicular to the biasing direction.

Furthermore, in the braking mechanism 5 that brakes the rotation of the retractable arm 3, a space is provided to the right of the cylindrical portion 24a of the damper 24, and a buffer spring 27 is placed in that space. This means that when the retractable arm 3 starts to rotate in the retracting direction, there is almost no braking action from the damper 24, and the axial movement of the damper cap 26 and damper 24 pressed against the connecting portion 10e of the retractable arm 3 is braked by the buffer spring 27, thereby reducing the rotational resistance of the retractable arm 3.

Therefore, even if the trigger shaft 33 is applied with a force strong enough to lightly abut the retractable arm 3 against the open door D, the retractable arm 3 is released from the standby position, and the retractable arm 3 rotates in the retracting direction to close the door D reliably and smoothly.

When the door D is opened from the closed state as shown in FIG. 7, the operation is the opposite of that when it is closed. That is, when the closed door D is rotated in the opening direction, the trigger shaft 33 moves relative to the tip of the straight portion of the engagement groove 3a of the retractable arm 3, causing the retractable arm 3 to rotate counterclockwise. The retractable arm 3 then comes into contact with the stopper 2d at the standby position and stops, and is held in that state by the biasing mechanism 4. When the retractable arm 3 stops, the trigger shaft 33 disengages from the engagement groove 3a of the retractable arm 3, and the door D rotates independently of the retractable arm 3 to open it.

In addition, in this embodiment, as shown in Figures 8 and 9, the spring adjustment screw 21 of the biasing mechanism 4 can be rotated with a hand screwdriver H through a hole on the front side of the main body case 2 while the device main body 1 is attached to the door frame F, thereby adjusting the biasing force of the biasing mechanism 4 (the arrow in Figure 8 indicates the adjustment operation in the direction to increase the biasing force).

In other words, the spring adjustment screw 21 is held immovable in the axial direction by the front wall of the main case 2 and the mounting screw spacer 9, and the adjustment nut 22 screwed to the spring adjustment screw 21 is housed in the cam member 20 immovably, so that when the spring adjustment screw 21 is rotated, the adjustment nut 22 and the cam member 20 move together in the axial direction of the spring adjustment screw 21 (the width direction of the main case 2). At the same time, the second spring case 19, which has an inclined cam surface 19b that slides against the inclined cam surface 20a of the cam member 20, moves in the longitudinal direction of the main case 2. This changes the amount of compression of the arm pressure spring 17, and the biasing force of the biasing mechanism 4 is adjusted.

By rotating the spring adjustment screw 21 as described above to adjust the biasing force of the biasing mechanism 4, the closing operation of the door D can be reliably assisted regardless of the weight of the door D, and the door D does not feel too heavy when opened.

In addition, in this door closing assistance device, the spring adjustment screw 21 is arranged to extend in the width direction of the horizontally long case body 2, and its rotation can be performed from the front side of the door frame F with the door D open, making it easier to adjust the biasing force compared to rotating a spring adjustment screw arranged to extend in the longitudinal direction of the case body from a direction parallel to the upper stile of the door frame.

In addition, with this door closing assistance device, when door D is open, the retractable arm 3 is normally held in the standby position, but even if some force is mistakenly applied to the retractable arm 3, causing it to rotate and be held in the retracted position, door D can still be closed normally as described below.

In other words, when the door D is open and the retractable arm 3 is in the retracted position, as the door D is closed, the trigger shaft 33 of the trigger 31, which rotates together with the door D, moves from the position of the notch on the bottom surface of the main case 2 into the introduction part of the engagement groove 3a of the retractable arm 3 as shown in FIG. 10(a) and abuts against the slide piece 11, and then, as shown in FIG. 10(b), slides the slide piece 11 toward the tip side of the retractable arm 3 against the elastic force of the slide piece pressing spring 12 and enters the straight part of the engagement groove 3a. Then, when the entire trigger shaft 33 enters the straight part of the engagement groove 3a, the slide piece 11 returns to its original position (as shown in FIG. 7) due to the elastic force of the slide piece pressing spring 12, and the door D is closed as usual.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

For example, in the above-described embodiment, the device body is installed on the door frame and the trigger is installed on the door, but the device body may be installed on the door and the trigger on the door frame instead.

1 Device body 2 Body case 3 Retractable arm 3a Engagement groove 4 Urging mechanism 5 Brake mechanism 10 Arm body 17 Arm pressure spring 18 First spring case (contact portion of urging mechanism)
18b Pressing surface 18b1 Arm holding surface 18b2 Inclined surface 24 Damper 27 Buffer spring 31 Trigger 33 Trigger axis A Straight line D which is a set of contact points of the biasing mechanism Door F Door frame O Rotation center S of the retractable arm Door stop

Claims (2)

the device comprises a door frame and a device main body attached to one of the doors rotatably provided on the door frame, and a trigger attached to the other door, the device main body comprising a main body case, a retractable arm rotatably supported on the main body case between a standby position corresponding to an open state of the door and a retracted position corresponding to a closed state of the door and engageable with the trigger, a biasing mechanism for biasing the retractable arm within the rotational plane, and a braking mechanism for braking the rotation of the retractable arm from the standby position to the retracted position,
In a door closing assist device in which, when the retractable arm of the device body is not engaged with a trigger in an open state, the retractable arm is held in the standby position by the biasing force received from the biasing mechanism, and when the door is closed, the trigger that has engaged with the retractable arm in the process releases the retractable arm from the standby position, causing the biasing mechanism to bias the retractable arm in a direction to rotate to the retracted position, and the retractable arm rotates while being braked by the brake mechanism in a state where it is engaged with the trigger, thereby drawing the door to the door frame,
When the trigger engages with the retractable arm during the process of closing the door, the contact point of the retractable arm with the biasing mechanism overcomes the biasing point of the biasing mechanism relative to the rotation center of the retractable arm, and the retractable arm is released from the standby position.
A door closing assistance device characterized in that the abutment portion of the biasing mechanism that abuts against the retractable arm has an arm holding surface perpendicular to the biasing direction of the biasing mechanism, and an inclined surface that is continuous with the arm holding surface and inclined in a direction away from the rotation center of the retractable arm, and is formed so that the arm holding surface abuts against the retractable arm in the standby position, and the focusing point is located halfway along the inclined surface. The door closing assistance device according to claim 1, characterized in that the braking mechanism comprises a linear damper that is held so as to be movable in the axial direction, and a buffer spring that brakes the axial movement of the damper that is pressed by the retractable arm during the process of closing the door.

Images