JP5874386B2 - Operating force reduction device - Google Patents

Description

  The present invention relates to an apparatus for reducing an operating force that gradually increases to a certain opening amount when opening a shoji from a fully closed state in an indoor sliding door equipped with a soft close mechanism.

In recent years, many indoor sliding doors are equipped with a soft-close mechanism that automatically closes a shoji screen while suppressing the occurrence of noise and damage, even when the shoji screen is closed vigorously (for example, In the indoor sliding door provided with such a soft close mechanism, it is necessary to pull and set the automatic closing tension coil spring to a predetermined length in accordance with the operation of opening the shoji. Since the operation force gradually increases to a certain opening amount (for example, about 100 mm) when opening from the fully closed state, the operability is deteriorated.
In addition, in the pull-type sash window, the weight of the shoji itself has increased due to the spread of shoji with multi-layer glass, etc. and the airtightness has been improved. In addition, there is one that attaches an opening operation force reducing device using the principle of a lever to a door rod of a shoji (see, for example, Patent Documents 2 to 4).

JP 2008-208586 A JP 2001-271520 A JP 2006-097248 A JP 2010-0479904 A

For indoor sliding doors equipped with a soft-close mechanism, it is conceivable to use an opening operation force reduction device that uses the principle of a lever attached to the door toe of a shoji. Because the amount is short and only works from the fully closed state of the shoji to the position opened about 20 mm, until the tension coil spring for automatic closing of the indoor sliding door equipped with the soft close mechanism is pulled to the predetermined length and set, for example about 100 mm It cannot be used for applications that reduce the operating force that gradually increases when opening the shoji.
In addition, in the opening operation force reducing device using the principle of the lever, if the distance from the fulcrum to the action point (for example, the arm tip) is increased to the required length, the above-mentioned gradually increasing operation of the indoor sliding door equipped with the soft close mechanism. It is possible to correspond to the application to reduce the force, but in order to reduce the operating force, the distance from the fulcrum to the force point (for example, the position where the handle is gripped) is longer than the distance from the fulcrum to the action point. Since the length of the handle (lever) becomes very long from the time when it is necessary to do so, it is not a practical configuration.

  Therefore, in view of the above-described situation, the present invention intends to solve the problem that the operation force that gradually increases when opening the shoji in the fully closed state can be effectively reduced in the indoor sliding door equipped with the soft close mechanism. It is in providing a practical operating force reduction device.

  In order to solve the above problem, the operation force reducing device according to the present invention reduces the operation force that reduces the operation force that gradually increases to a certain opening amount when opening the shoji from the fully closed state in the indoor sliding door equipped with the soft close mechanism. A large-diameter pulley and a small-diameter pulley that are coaxially and integrally rotated, and are rotatably supported around a first thickness direction axis located on the door end side of the shoji, and the first thickness direction axis A swinging piece swinging around a second thickness direction axis located closer to the door end than the door end of the shoji door, or one side thereof, and one end being hooked on the large-diameter pulley, and the other end being The first flexible long member that is hooked to the operation piece, and one end are hooked to the small-diameter pulley, and are supported so as to be rotatable around a third thickness direction axis located on the door bottom side of the swinging piece. The other end of the direction change pulley In a state where the second flexible elongate member hooked on the member located at the door tip of the child and the swinging piece protrudes from the door tip or its side, from the door tip or its side Elastic urging means for urging in the direction to be immersed in the door butt side. By operating the operation piece and pulling the first flexible long member, the large diameter pulley and the small diameter pulley are rotated. The direction change pulley is urged toward the door tip side by the tension of the second flexible long member that moves and is wound around the small-diameter pulley, and the swing piece moves from the door tip of the shoji or from the side thereof. It protrudes.

According to such a configuration, it is not a configuration in which one end portion of the swing lever such as the opening operation force reduction device using the lever principle is directly projected and retracted from the front end of the shoji and pressed against the vertical frame. Since the swing piece protrudes from the door tip or its side by the tension of the second flexible elongate member via the direction changing pulley attached to the piece, there is no need to provide a swing lever. The whole can be configured compactly.
In addition, one end of the first flexible elongate member pulled by the operation piece is hooked on the large-diameter pulley, and the second flexible elongate member is driven over the direction change pulley to drive the swing piece. Since one end is hooked on the small-diameter pulley, the tension can be amplified by the difference in diameter (ratio) between the large-diameter pulley and the small-diameter pulley, so the force that reduces the operating force (assist force) with a compact configuration Can be bigger.
Furthermore, one end of the second flexible elongate member is hooked on the small-diameter pulley, the other end is hooked on the member located at the door tip of the shoji, and the intermediate portion is on the door bottom side of the swing piece. The angle formed by the second flexible elongate member that is spanned on the door bottom side of the direction change pulley that is positioned and is changed over the direction change pulley is determined by the direction change pulley and the swing piece. Since it increases as it swings toward the door end, the larger the kicking amount (the length of the swinging piece protruding from the door tip or its side), the greater the operating amount of the operating piece (the rotation of the large-diameter pulley and small-diameter pulley). Since the kicking amount with respect to the (movement angle) decreases, the force (assist force) for pushing the vertical frame by the swinging piece gradually increases as the shoji is opened from the fully closed state.
Therefore, in an indoor sliding door equipped with a soft-close mechanism, when the shoji is opened from the fully closed state, the operating force gradually increases to a certain opening amount, but in order to reduce this gradually increasing operating force, the vertical frame is formed by a swinging piece. Since the pushing force (assist force) is also gradually increased, the force required when the operator opens the shoji from the fully closed state can be effectively reduced.

Here, it is preferable to change the diameters of the large-diameter pulley and the small-diameter pulley so that the ratio of the diameter of the large-diameter pulley to the diameter of the small-diameter pulley gradually increases when the shoji is opened from the fully closed state.
According to such a configuration, when the shoji is opened from the fully closed state, the ratio of the diameter of the large pulley to the diameter of the small pulley gradually increases, so the tension amplification factor also gradually increases. The gradually increasing operation force in the indoor sliding door can be further effectively reduced. For example, operability (operation feeling) can be greatly improved by making the force required when the operator opens the shoji from the fully closed state substantially constant.

  As described above, according to the operation force reducing device according to the present invention, in the indoor sliding door equipped with the soft close mechanism, (a) since it is not necessary to provide the swing lever, the entire device can be configured compactly. (A) The ability to reduce the operating force (assist force) can be increased by a compact configuration using a large-diameter pulley and a small-diameter pulley, and (c) a direction-changing pulley attached to the door bottom side of the swinging piece The swinging piece protrudes from the door tip or its side by the tension of the second flexible elongate member through the door, and as the kicking amount increases, the kicking amount with respect to the operating amount of the operating piece decreases. Therefore, as the shoji is opened from the fully closed state, the force that pushes the vertical frame by the swing piece (assist force) gradually increases, effectively reducing the force required for the operator to open the shoji from the fully closed state. That can Rukoto, a marked effect equal.

1 is a front view of an indoor sliding door to which an operation force reducing device according to an embodiment of the present invention is applied. It is a partial vertical front view which shows the structure of the same operation force reduction apparatus, and has shown the fully closed state of the shoji. It is a disassembled perspective view of the operation force reducing device. It is a disassembled perspective view of a rocking piece. It is a disassembled perspective view of the components around an operation piece. It is a front view which shows the state which operated the operation piece and the rocking | fluctuation piece protruded from the door butt end and has pushed the vertical frame. It is a front view which shows the state which operates the operation piece and the rocking | fluctuation piece protrudes most from the door butt end.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments shown in the accompanying drawings, and includes all the embodiments that satisfy the requirements described in the claims. It is a waste.
In the present specification, the front is the front, the rear is the rear, and the left and right are the front in the closing direction of the external obstacle D1 (see arrow A1 in FIG. 1), viewed from the left. Is a front view.

As shown in the front view of FIG. 1, the indoor sliding door S according to the embodiment of the present invention has an opening E that is a doorway, for example, partitioned by a frame F by a sliding-type external obstacle D <b> 1 and internal impingement D <b> 2. For sliding doors that open and close, and are soft closing mechanisms that automatically close while suppressing the generation of noise and damage, even when the shoji D1, D2 is closed from the open state in the closing direction A1. Brake devices B and B are provided.
Further, since the tension coil spring for automatically closing the sliding door brake devices B and B needs to be pulled and set to a predetermined length when opening the shojis D1 and D2, the shojis D1 and D2 are opened from the fully closed state. Since the operation force gradually increases to a certain opening amount (for example, about 100 mm), the operation force reducing devices 1 and 1 for reducing the operation force are provided.

Since the operation force reduction devices 1 and 1 according to the embodiment of the present invention are the same, the operation force reduction device 1 attached to the external obstacle D1 will be described below as a representative.
As shown in the partial longitudinal front view of FIG. 2, the operating force reduction device 1 is rotatable around a first thickness direction axis G1 that is a left and right support shaft located on the front side (door side) of the shoji D1. A large-diameter pulley 2 and a small-diameter pulley 3 that are supported coaxially (concentrically) and rotate together, and a first support shaft that is located on the front side (door side) of the first thickness direction axis G1. 2. Swing piece 4 swinging back and forth from door tip C of shoji D1 and one end 11A are hooked to large diameter pulley 2 by swinging back and forth from the upper side of large diameter pulley 2 and small diameter pulley 3 around thickness direction axis G2. The first wire rope 11, which is a first flexible long member that extends substantially downward from the front side of the large-diameter pulley 2, and the other end 11 </ b> B is hooked on the operation piece H, and the one end 12 </ b> A hooks on the small-diameter pulley 3. It is stopped and extends from the front side of the small-diameter pulley 3 substantially rearward, and the middle part Bridge over the rear side (door bottom side) of the direction change pulley 5 that is supported on the rear side (door bottom side) of the piece 4 and is rotatably supported around the third thickness direction axis G3, which is a lateral support shaft. The second wire rope 12 is a second flexible long member that is hooked to a stepped pin 19 that is a member whose other end 12B is located at the front end portion (door tip portion) of the shoji D1. In a state where the moving piece 4 protrudes from the door tip C, a tension coil spring 6 is provided which is an elastic biasing means for urging the swinging piece 4 in a direction to immerse the swing piece 4 to the rear side (door bottom side) from the door tip C. .
Further, the operating force reduction device 1 operates the operation piece H to pull the first wire rope 11, whereby the large-diameter pulley 2 and the small-diameter pulley 3 are rotated by the tension of the first wire rope 11, and the small-diameter pulley 3. The direction change pulley 5 is urged toward the door end side by the tension of the second wire rope 12 wound around, and the swing piece 4 protrudes from the door tip C of the shoji D1. The swing piece 4 causes the vertical frame L (FIG. 1). (Refer to reference.) When the shoji D1 is opened from the fully closed state, the operation force that gradually increases to a certain opening amount is reduced by the pressing force (assist force).

As shown in the exploded perspective view of FIG. 3, the large-diameter pulley 2 and the small-diameter pulley 3 are manufactured integrally, and the rivet 21 is connected to the through hole 8 </ b> A of the mechanism cover 8, the large-diameter pulley 2, and the small-diameter pulley 3. By caulking the shaft end through the central through hole 3A and a through hole (not shown) of the mechanism part case 7, the large diameter pulley 2 and the small diameter pulley 3 are separated by the mechanism part case 7 and the mechanism part cover 8 (the mechanism part case 7 and When the mechanism cover 8 and the mechanical components are attached to the shoji D1, the shovel D1 is supported so as to be rotatable around the first thickness direction axis G1.
Note that the large-diameter pulley 2 and the small-diameter pulley 3 may be manufactured separately and connected and fixed to be integrated.
Further, the torsion coil spring 13 is accommodated in the annular recess 3B of the large diameter pulley 2 and the small diameter pulley 3, and one end 13A of the torsion coil spring 13 is inserted into the through hole 8D of the mechanism cover 8. The shaft end is crimped and inserted into the spring support hole 14A of the rivet 14 erected on the right surface of the mechanism cover 8, and the other end 13B of the torsion coil spring 13 is inserted into the annular recess 3B. It is inserted into the spring support hole 3C and hooked.

As shown in FIG. 3, the rivet 22 is swung by caulking the shaft end through a through hole 4 </ b> A in the front end portion (door end side end portion) of the swing piece 4 and a not-shown through hole in the mechanism case 7. The piece 4 is forward of the first thickness direction axis G1 (door end side) by the mechanical part case 7 (by the sliding part D1 when the mechanical part case 7, the mechanical part cover 8 and the mechanical part are attached to the sliding part D1). Is supported so as to be swingable around the second thickness direction axis G2.
Further, as shown in the exploded perspective view of FIG. 4, the direction change pulley 5 is positioned between the left and right through holes 4 </ b> B and 4 </ b> B on the rear side (door bottom side) of the swing piece 4. In a state where 5A is aligned with the through holes 4B and 4B of the swing piece 4, the rivet 23 is inserted into one through hole 4B of the swing piece 4, the through hole 5A of the direction changing pulley 5, and the other pass of the swing piece 4. By caulking the shaft end through the hole 4B, the direction changing pulley 5 is supported by the swing piece 4 so as to be rotatable around the third thickness direction axis G3.
Further, as shown in FIG. 3, in a state where the stepped pin 19 is inserted into the terminal collar 16 to which the other end 12B of the second wire rope 12 is attached, both ends of the stepped pin 19 are connected to the mechanism case 7 and Since the other end 12B of the second wire rope 12 is supported by the through holes 7B, 8B of the mechanism cover 8, the other end 12B of the second wire rope 12 is attached to the stepped pin 19 (the mechanism case 7, the mechanism cover 8, and the mechanism parts are attached to the shoji D1. In this state, it is hooked on a member located at the front end (door tip) of the shoji D1.

As shown in FIGS. 2 and 3, one end 6 </ b> A of the tension coil spring 6 is hooked on the spring hanging piece 4 </ b> D projecting downward and rearward from the second thickness direction axis G <b> 2 of the swing piece 4, The other end 6 </ b> B of the tension coil spring 6 is hooked to the rivet 20, which is a spring hook portion, whose shaft end is crimped through the through hole 8 </ b> C of the mechanism cover 8 and the through hole 7 </ b> C of the mechanism case 7.
3, the rivets 24, 24,... Are swaged through the through holes 8E, 8E,... Of the mechanism cover 8 and the through holes 7E, 7E,. The mechanism part cover 8 is firmly fixed to the mechanism part case 7 in a state where the mechanical parts are accommodated between the mechanism part case 7 as described above, and from the front of the upper and lower mounting holes 7F and 7F, FIG. As shown in FIG. 2, the operating force reducing device 1 can be easily attached to the shoji D1 by screwing the attachment screws 25, 25 to the shoji D1.

As shown in the exploded perspective view of FIG. 5, the pair of front and back operation knobs 9, 9 which are operation pieces H when opening the shoji D <b> 1 are slid vertically by the pair of front and back operation unit cases 10, 10. Supported as possible.
That is, with the long holes 10A, 10A in the vertical direction, the back surfaces of the pair of operation unit cases 10, 10 are aligned within the opening formed in the shoji D1, and the stepped pins 19, 19,. The operation part cases 10 and 10 are fixed to the door end side end of the shoji D1 by caulking the shaft end through.
And the operation knobs 9 and 9 are accommodated in the operation part cases 10 and 10, and the mounting screw 17 is connected to the through hole 9A of one operation knob 9 and the other end 11B of the first wire rope 11 as shown in FIG. By screwing the nut 18 through the attached terminal collar 15 and the through hole 9A of the other operation knob 9, the operation knobs 9 and 9 are supported by the operation part cases 10 and 10 so as to be slidable in the vertical direction.
Therefore, the 1st wire rope 11 can be pulled by pushing down the operation knobs 9 and 9 which are the operation pieces H (refer FIG.2 and FIG.3).

Next, the detail of operation | movement of the operating force reduction apparatus 1 is demonstrated.
As shown in the front view of FIG. 6, when the operator depresses the operation piece H (see arrow I in the figure), the first wire rope 11 as the first flexible elongated member is pulled downward, and the first Since one end (upper end) of the 1 wire rope 11 is hooked on the large diameter pulley 2, the large diameter pulley 2 and the small diameter pulley 3 rotate (see arrow J in the figure).
Therefore, the second wire rope 12, which is a second flexible long member whose one end (lower end) is hooked on the small diameter pulley 3, is wound around the small diameter pulley 3, and the second wire rope 12 is the direction change pulley 5. Since it is bridged on the rear side (door bottom side) and is hooked on the stepped pin 19 at the front end (door tip) of the shoji D1, the direction change pulley 5 is driven by the tension of the second wire rope 12. As shown in FIG. 6, the oscillating piece 4 protrudes from the door tip C of the shoji D1 and pushes the vertical frame L, so that the shoji D1 is opened. When the operation piece H is opened in the direction A2 and pushed down to the lowest position as shown in the front view of FIG. 7, the swing piece 4 protrudes most from the door tip C.

Here, the protruding swing piece 4 as shown in FIG. 7 swings as shown in FIG. 2 due to the restoring force of the elastically deformed tension coil spring 6 when the operator releases the hand after operating the operation piece H. The moving piece 4 returns to the state where it is immersed behind the door tip C of the shoji D1 (to the bottom of the door).
In this state, the torsion coil spring 13 is configured such that the urging force acts in the direction in which the small-diameter pulley 3 winds up the second wire rope 12, so that the second wire rope 12 is not slackened. The 2-wire rope 12 does not come off from the small-diameter pulley 3 and the direction change pulley 5.
As the swing piece 4 swings, the relative position of the swing piece 4 and the second wire rope 12 changes. However, as shown in FIGS. Since the escape groove 4C is formed on the side), the swing piece 4 and the second wire rope 12 do not interfere with each other.

According to the configuration of the operation force reducing device 1 as described above, one end of the swing lever such as the opening operation force reducing device using the lever principle is directly projected and retracted from the front end of the shoji and pushed into the vertical frame. It is not the structure which hits but the structure which makes the rocking piece 4 protrude from the door tip C by the tension | tensile_strength of the 2nd wire rope 12 which is a 2nd flexible elongate member via the direction change pulley 5 attached to the rocking piece 4. Therefore, since it is not necessary to provide a swing lever, the entire apparatus can be configured compactly.
Further, one end 11A of the first wire rope 11 which is a first flexible long member pulled by the operation piece H is hooked on the large-diameter pulley 2 and is spanned on the direction changing pulley 5 so that the swing piece 4 is attached. Since one end 12A of the second wire rope 12 to be driven is hooked on the small-diameter pulley 3, the tension can be amplified by the difference (ratio) in diameter between the large-diameter pulley 2 and the small-diameter pulley 3, so that the compact configuration Thus, the force for reducing the operation force (assist force) can be increased.

Furthermore, one end 12A of the second wire rope 12 is hooked to the small-diameter pulley 3, and the other end 12B of the second wire rope 12 is hooked to a member located at the door tip of the shoji D1, D2, and the middle portion is rocked. The angle formed by the second wire rope 12 spanned on the door bottom side of the direction changing pulley 5 located on the door bottom side of the moving piece 4 and the direction of the direction changing pulley 5 is changed. 2, 6 and 7, since the direction change pulley 5 and the swing piece 4 become larger as they swing toward the door end, the kicking amount (the length of the swing piece 4 protruding from the door tip C) is increased. The larger the distance is, the smaller the amount of kicking with respect to the operation amount of the operation piece H (the rotation angle of the large-diameter pulley 2 and the small-diameter pulley 3) is, so that as the shojis D1 and D2 are opened from the fully closed state, the swing piece 4 to push the vertical frame L (assist ) Increases gradually.
Therefore, in the indoor sliding door S equipped with the soft close mechanism, when the shoji D1, D2 is opened from the fully closed state, the operating force gradually increases to a certain opening amount. In order to reduce this gradually increasing operating force, the swing piece 4, the force (assist force) for pushing the vertical frame L gradually increases, so that the force required when the operator opens the shojis D1 and D2 from the fully closed state can be effectively reduced.

Furthermore, when the shojis D1 and D2 are opened from the fully closed state, the diameters of the large diameter pulley 2 and the small diameter pulley 3 are changed so that the ratio of the diameter of the large diameter pulley 2 to the diameter of the small diameter pulley 3 gradually increases. Is also easy. For example, a configuration in which the diameter of the large-diameter pulley 2 is made constant while the diameter of the small-diameter pulley 3 is gradually reduced, a configuration in which the diameter of the small-diameter pulley 3 is made constant and the diameter of the large-diameter pulley 2 is gradually increased, and the diameter of the large-diameter pulley 2 is gradually increased. A configuration in which the diameter of the small-diameter pulley 3 is gradually reduced can be employed.
According to such a configuration, when the shojis D1 and D2 are opened from the fully closed state, the ratio of the diameter of the large-diameter pulley 2 to the diameter of the small-diameter pulley 3 is gradually increased. The gradually increasing operating force in the indoor sliding door S equipped with the soft close mechanism can be further effectively reduced. For example, the operability (operation feeling) can be greatly improved if the force required when the operator opens the shoji D1, D2 from the fully closed state is made substantially constant.

In the above description, the operation piece H is located below the large diameter pulley 2 and the small diameter pulley 3, and the swing piece 4 is located substantially above the large diameter pulley 2 and the small diameter pulley 3. Although shown, it is good also as a structure which turned these upside down, and in that case, the operation piece H located above the large diameter pulley 2 and the small diameter pulley 3 is operated upwards, for example, the shoji D1, D2 Can be opened.
Moreover, although the case where the 1st flexible elongate member and the 2nd flexible elongate member were the wire ropes 11 and 12 was shown, the 1st flexible elongate member and the 2nd flexible elongate The member is not limited to a wire rope, and may be a narrow belt, for example.
Furthermore, a unit in which all parts of the operation force reducing device 1 are integrated may be externally attached to the door tip of the shoji. According to such a configuration, it can be easily attached to an existing sliding door and used quickly. can do. In the case of this configuration, the swing piece that swings in the front-rear direction appears and disappears from the lateral side of the front end of the shoji door.

A1 Closing direction A2 Opening direction B Sliding door brake device (soft closing mechanism)
C door tip D1 external obstacle D2 internal obstacle E opening F frame G1 first thickness direction axis G2 second thickness direction axis G3 third thickness direction axis H operation piece I operation direction J, K rotation direction L vertical frame S indoor Sliding door 1 Operating force reduction device 2 Large diameter pulley 3 Small diameter pulley 3A Through hole 3B Circular recess 3C Spring support hole 4 Oscillating piece 4A Through hole 4B Through hole 4C Relief groove 4D Spring hook 5 Direction change pulley 5A Through hole 6 Tension Coil spring (elastic urging means) 6A, 6B Terminal 7 Mechanism part case 7B, 7C, 7E Through hole 7F Mounting hole 8 Mechanism part cover 8A, 8B, 8C, 8D, 8E Through hole 9 Operation knob 9A Through hole 10 Operating part Case 10A Long hole 10B Through hole 11 First wire rope (first flexible long member)
12 Second wire rope (second flexible long member)
11A, 12A One end 11B, 12B The other end 13 Torsion coil spring 13A, 13B End 14 Rivet 14A Spring support hole 15, 16 End collar 17 Mounting screw 18 Nut 19 Stepped pin 20 Rivet (spring hooking portion) 21, 22, 23, 24 Rivet 25 Mounting screw

Claims (2)

In an indoor sliding door equipped with a soft close mechanism, an operation force reducing device that reduces the operation force gradually increasing to a certain opening amount when opening the shoji from the fully closed state,
A large-diameter pulley and a small-diameter pulley that are coaxially and integrally rotated, supported rotatably around a first thickness direction axis located on the door end side of the shoji,
A swinging piece that swings around a second thickness direction axis located closer to the door end side than the first thickness direction axis and protrudes and retracts from the door tip of the shoji or its side;
A first flexible elongated member having one end hooked to the large-diameter pulley and the other end hooked to the operation piece;
One end is hooked on the small-diameter pulley, and is spanned on the door bottom side of the direction change pulley supported rotatably around the third thickness direction axis located on the door bottom side of the swing piece, and the other end is A second flexible elongate member hooked on a member located at the door toe of the shoji,
An elastic urging means for urging the oscillating piece in a direction in which the oscillating piece protrudes from the door tip or from the side thereof, and to be inserted into the door butt side rather than the door tip or the side thereof;
By operating the operation piece and pulling the first flexible long member, the large-diameter pulley and the small-diameter pulley rotate, and the second flexible long member wound around the small-diameter pulley is wound. The operation force reducing device according to claim 1, wherein the direction change pulley is urged toward the door tip side by tension, and the swing piece protrudes from the front end of the shoji door or from the side thereof.   The diameter of the large diameter pulley and the small diameter pulley are changed so that the ratio of the diameter of the large diameter pulley to the diameter of the small diameter pulley gradually increases when the shoji is opened from the fully closed state. Operation force reduction device.

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