JP2019027033A - Speed adjustment device - Google Patents

Abstract

To provide a speed adjustment device which can adjust a moving speed of a cord related to opening and closing of a shield in a shading device, and enables quality maintenance such as failure prevention and cord friction prevention in making braking force act to the movement of the cord.SOLUTION: A speed adjustment device 6 of this invention comprises: a brake section 6a which can adjust moving speeds of cords (for example, lifting cords C1, C2, C3) related to opening and closing of a shield, and makes braking force act to the movement of the cords; and overload limitation means (for example, a serration structure which can transmit and separate a lower end portion 641a of a roller axis 641 and an upper end portion 644b of a gear axis 644a mutually) which limits overload of the brake section 6a when the moving speeds of the cords exceed a predetermined setting speed.SELECTED DRAWING: Figure 8

Description

  The present invention can be applied to a shielding device such as a horizontal blind, a pleated screen, a roman shade, a vertical blind accordion curtain, or a roll screen. The present invention relates to a speed adjusting device that brakes automatically.

  As a shielding device that can use a speed adjusting device that limits the moving speed of a predetermined cord and brakes the moving speed of the shielding material to a certain value or less, there is typically a horizontal blind that performs a hand-operating operation of the lifting / lowering cord.

  In such a horizontal blind, a plurality of slats are suspended and supported from a head box via a plurality of ladder cords, and a bottom rail is suspended and supported at the lower end of the ladder cord. A plurality of lifting / lowering cords are inserted into each slat. One end of each lifting / lowering cord is connected to the bottom rail, and the other end is guided into the head box and connected to the operating device.

  In the operating device, a gear mechanism is disposed in the head box, and an input shaft of the gear mechanism projects out of the head box from an opening provided in the head box, and a tilt operating rod is provided at the tip of the input shaft. And the angle of the slats can be adjusted by rotating the tilt operation rod.

  On the other hand, the lifting / lowering cord is led out from the inside of the head box through the cord outlet and connected to one end portion of the operation cord via the cord equalizer, and the other end portion of the operation cord is connected to the bottom rail. Alternatively, the lifting / lowering cord may be guided from the head box through the cord outlet into the tilt operation rod and connected to the knob at the lower end thereof.

  When the operation cord and the knob are operated to pull out the lifting / lowering cord from the head box, the bottom rail is pulled up and the slat is raised.

  If the pulling-out operation of the lifting / lowering cord is stopped, the stopper device is actuated to prevent the slats and the bottom rail from falling by their own weight. Further, when the operation of the stopper device is released, the slat and the bottom rail descend based on their own weight.

  There is known a speed adjusting device that can be applied to such a horizontal blind and generates a braking force only in one direction of movement of a cord to be speed adjusted (see, for example, Patent Document 1).

  In particular, the speed adjustment device disclosed in Patent Document 1 sandwiches a cord (for example, a lifting / lowering cord) with a pair of rollers, the pair of rollers detects the movement direction of the cord, and the cord moves in one direction. In this case, a centrifugal brake is applied by narrowing the pressure with a pair of rollers, and when the cord moves in the other direction, it is made non-narrow by the pair of rollers (relaxing the narrow pressure state), and depending on the moving direction of the cord Switching is to be performed.

International Publication No. 2016/194642

  As described above, there is disclosed a speed adjustment device in which a pair of rollers switches between a narrow pressure state and a non-narrow pressure state with respect to a cord according to the moving direction of the cord, but a set speed at which the pair of rollers generate a braking force. If it rotates at a speed exceeding 1, there is a risk of damage or wear of parts, and there is room for improvement.

  That is, when a brake unit that generates braking torque is provided for the rotation shaft (roller shaft) of one roller (drive roller) of the pair of rollers, the roller shaft on which the brake unit is provided is excessive. When the rotation of the speed occurs, the roller shaft and the brake part are overloaded, and there is a possibility that damage or wear of the cord and the brake part may occur.

  In view of the above-mentioned problems, the present invention makes it possible to adjust the moving speed of the cord related to the opening and closing of the shielding material in the shielding device, and to prevent failures when the braking force is applied to the movement of the cord and to prevent the wear of the cord. It is an object of the present invention to provide a speed adjusting device that enables maintenance.

The speed adjusting device according to the present invention is a speed adjusting device that can adjust a moving speed of a cord related to opening and closing of a shielding material, and includes a brake unit that applies a braking force to the movement of the cord, and a moving speed of the cord. Overload limiting means for limiting an overload of the brake means when the speed exceeds a predetermined set speed.
As a result, it is possible to maintain quality such as failure prevention and cord wear prevention when a braking force is applied to the movement of the cord.

The speed adjusting device according to the present invention further includes a rotating body that rotates in accordance with the movement of the cord, and the brake means controls the movement of the cord by applying a braking torque to the shaft of the rotating body. It is characterized by being configured to apply power.
As a result, the braking torque can be efficiently applied and the overload can be limited.

Further, in the speed adjustment device according to the present invention, the overload limiting means transmits the rotation at the same speed as the rotation of the rotating body to the brake means when the rotation of the rotating body is within a predetermined speed threshold. And, when the rotation of the rotating body exceeds the predetermined speed threshold, the rotation of the braking means is limited by transmitting a rotation lower than the rotating speed of the rotating body to the braking means. It is characterized by.
As a result, the application of the braking torque and the overload limitation are reliably realized.

Further, in the speed adjustment device according to the present invention, the overload limiting means includes a shaft holding portion that holds the shaft of the rotating body and a shaft that applies braking torque by the brake means so as to be separable from each other. It is characterized by having.
Thereby, the axis | shaft of a rotary body and the axis | shaft which concerns on a brake means can be isolate | separated reliably, and the performance which concerns on an overload restriction | limiting can be improved.

Further, in the speed adjustment device according to the present invention, the overload limiting means is configured to hold the rotary body and the shaft of the rotary body to which braking torque is applied by the brake means so as to be separably engaged and held. It has the part.
Thereby, a rotating body can be supported by a single axis | shaft, and stability concerning an overload restriction | limiting can be improved.

Further, in the speed adjusting device according to the present invention, the overload limiting means includes the shaft holding portion configured by serration engagement, and limits the overload of the brake means.
Thereby, the application of the braking torque and the limitation of the overload can be easily adjusted without increasing the size of the speed adjusting device.

Further, in the speed adjusting device according to the present invention, the overload limiting means is characterized in that the shaft holding portion is constituted by an elastically deformable damping member and limits overload of the brake means.
Accordingly, the configuration of applying the braking torque and limiting the overload can be realized at a low cost (small number of parts) without increasing the size of the speed adjusting device.

Further, in the speed adjusting device according to the present invention, the overload limiting means is characterized in that the shaft holding portion is constituted by a clutch spring to limit the overload of the brake means.
Thereby, the application of braking torque and the threshold setting for overload restriction can be easily realized without increasing the size of the speed adjusting device.

The speed adjusting device according to the present invention further includes a second rotating body that sandwiches the cord so as to face the rotating body, and a distance between the rotating body and the second rotating body is a moving direction of the cord. The code is configured to detect whether or not the cord has moved and to move in the proximity or separation according to the distance.
As a result, the cord movement detection function is also provided, and the application of the braking torque and the overload limitation are realized.

In the speed adjusting device according to the present invention, the brake means is configured to apply a braking torque to the shaft of the rotating body by a centrifugal brake or a predetermined damper, and amplifies the braking torque based on the rotation of the rotating body. And means for allowing the braking torque to be adjusted in multiple stages.
As a result, the braking torque amplification function and the braking torque adjustment function are also provided, and the application of the braking torque and the overload limitation are realized.

  According to the present invention, even when the shaft of the drive roller connected to the brake unit rotates at a speed exceeding the set speed for generating the braking force, it is possible to prevent failure of the members related to the speed adjusting device, to prevent cord wear, etc. Quality maintenance is possible.

It is a front view which shows schematic structure of the horizontal blind comprised as a shielding apparatus of one Embodiment by this invention. It is a perspective view of the speed adjustment apparatus of Example 1 by this invention. It is a disassembled perspective view of the speed adjusting device of Example 1 by this invention. It is a see-through | perspective top view of the gear mechanism in the speed regulator of Example 1 by this invention. (A), (b) is a top view which shows roughly operation | movement of the speed adjusting device of Example 1 by this invention, respectively. (A), (b) is the non-pull operation of the raising / lowering cord when raising / lowering a slat regarding the speed adjustment apparatus of Example 1 applied to the horizontal blind comprised as a shielding apparatus of one Embodiment by this invention, respectively. It is a schematic front view which shows operation | movement and an effect | action at the time (at the time of slat fall) and pulling operation (at the time of slat rise). (A) is a figure which shows schematic structure of the drive roller provided with the overload limiting mechanism in the speed adjusting device of Example 1 by this invention, (b) is in the conventional speed adjusting device which is not provided with the overload limiting mechanism. It is a figure which shows schematic structure of the roller shaft of a comparative example. (A), (b) is a figure which shows the operation | movement at the time of the normal time (at the time of non-overload restriction | limiting) and the time of an overload restriction | limiting of a drive roller provided with the overload restriction mechanism in the speed regulator of Example 1 by this invention, respectively. It is. It is a figure which shows the operation | movement at the time of the overload restriction | limiting in the speed regulator of Example 1 applied to the horizontal blind comprised as a shielding apparatus of one Embodiment. (A) is a figure which shows schematic structure of the drive roller provided with the overload limiting mechanism in the speed regulator of Example 2 by this invention, (b), (c) is each normal operation in the AA 'cross section. It is a figure which shows schematic operation | movement at the time of time and an overload limitation. (A) is a figure which shows schematic structure of the drive roller provided with the overload limiting mechanism in the speed regulator of Example 3 by this invention, (b), (c) is each normal operation in the AA 'cross section. It is a figure which shows schematic operation | movement at the time of time and an overload limitation. (A) is a figure which shows schematic structure of the drive roller provided with the overload limiting mechanism in the speed regulator of Example 4 by this invention, (b), (c) is each normal operation in the AA 'cross section. It is a figure which shows schematic operation | movement at the time of time and an overload limitation. (A) is a figure which shows schematic structure of the drive roller provided with the overload limiting mechanism in the speed regulator of Example 5 by this invention, (b), (c) is each normal operation in the AA 'cross section. It is a figure which shows schematic operation | movement at the time of time and an overload limitation. (A), (b) is a figure which shows schematic structure of a drive roller provided with the overload limiting mechanism in the speed regulator of Example 6, 7 by this invention, respectively.

  Hereinafter, with reference to the drawings, the speed adjusting device of each example in the shielding device of one embodiment according to the present invention will be described. In the present specification, the upper side and the lower side of the horizontal blind configured as the shielding device shown in FIG. 1 are respectively upward (or upward) according to the direction in which the shielding material (slat) is suspended. ) And downward direction (or lower side), the left direction in the figure is defined as the left side of the horizontal blind, and the right direction in the figure is defined as the right side of the horizontal blind. In the example described below, the side to be visually recognized is the front side (or the indoor side) and the opposite side is the rear side (or the outdoor side) with respect to the front view of the horizontal blind shown in FIG.

[Shielding device]
FIG. 1 is a front view showing a schematic configuration of a horizontal blind configured as a shielding device according to an embodiment of the present invention. In the horizontal blind according to the present embodiment, a multi-stage slat 3 is supported by a ladder cord 2 suspended from the vicinity of the left and right ends of the head box 1 and from a substantially central portion, and a bottom rail 4 is provided at the lower end of the ladder cord 2. Is supported by suspension.

  Further, from the vicinity of the left and right end portions of the head box 1, the lifting cords C1 and C3 are suspended from the ladder cord 2 on the outdoor side, respectively, and are attached to the indoor ladder cord 2 from the substantially central portion of the head box 1. Then, the lifting / lowering cord C2 is suspended. The bottom rail 4 is attached to the lower ends of the elevating cords C1, C2, and C3.

  A support member 5 that supports the ladder cord 2 and the lifting / lowering cords C1, C2, and C3 is disposed in the head box 1, and a hexagonal bar-shaped drive shaft 13 is inserted into the support member 5.

  A tilt drum 51 is rotatably supported on the support member 5, and the drive shaft 13 is inserted into the tilt drum 51 so as not to be relatively rotatable. Therefore, when the drive shaft 13 is rotated, the tilt drum 51 is rotated, and the angles of the multi-stage slats 3 suspended and supported by the ladder cord 2 are adjusted in phase. The support member 5 is provided with a turning pulley 52 that turns the other ends of the lifting / lowering cords C1, C2, and C3 that are attached to the bottom rail 4 in the longitudinal direction in the head box 1. Is preferred.

  On the right end side in the head box 1, there is formed a tilt window portion 11 for hanging a tilt operation rod 9 having one end attached to a tilt operation grip 10. The other end of the tilt operation rod 9 is connected to the gear mechanism 12 in the head box 1 through the tilt window 11. The gear mechanism 12 is connected to the drive shaft 13 and is configured to transmit the rotation of the tilt operation rod 9 to the rotation of the drive shaft 13. Therefore, by rotating the tilt operation grip 10, the rotation is transmitted to the drive shaft 13, and the angles of the multi-stage slats 3 suspended and supported by the ladder cord 2 through the support member 5 can be adjusted. it can.

  The other ends of the lifting / lowering cords C1, C2, and C3 that attach one end to the bottom rail 4 are guided to the right end side in the head box 1 through the support member 5, and through the stopper device 15 in the head box 1. After that, when inserted through the speed adjustment device 6 according to the present invention installed in the head box 1, it is suspended from the cord outlet 14 and connected to the cord equalizer 8.

  In the example shown in FIG. 1, one end of the operation cord 7 is attached to the lower end of the cord equalizer 8 that connects the ends of the plurality of lifting cords C1, C2, and C3 suspended from the cord outlet 14. The other end of the operation cord 7 is attached to the bottom rail 4.

  However, as a modification related to the hanging of the plurality of lifting / lowering cords C1, C2, and C3, the ends of the plurality of lifting / lowering cords C1, C2, and C3 are guided from the cord outlet 14 into the tilt operation rod 9 without being suspended. It can also be set as the structure connected to a knob in a lower end part.

  In the example shown in FIG. 1, if the operation cord 7, the code equalizer 8, or the plurality of lift cords C 1, C 2, C 3 are operated and the lift cords C 1, C 2, C 3 are pulled out from the cord outlet 14, 4 is pulled up and the slat 3 is raised. Therefore, the lifting / lowering cords C1, C2, and C3 function as traction cords that perform traction when the slat 3 and the bottom rail 4 are raised.

  If the pulling-out operation of the lifting / lowering cords C1, C2, and C3 is stopped, the stopper device 15 is activated, and the slat 3 and the bottom rail 4 are prevented from falling by their own weight. Moreover, if the action | operation of the stopper apparatus 15 is cancelled | released, the slat 3 and the bottom rail 4 will descend | fall based on the dead weight.

  In this way, the horizontal blind having a configuration in which the slat 3 is lowered by its own weight by the weight of the bottom rail 4 and the slat 3 by releasing the operation of the stopper device 15 and the slat 3 is lifted by directly pulling the elevating cords C1, C2, and C3. Then, it is preferable to provide the speed adjusting device 6 so that the slat 3 can be lowered smoothly and at an appropriate speed.

  The speed adjusting device 6 is a device that brakes the moving speed of the slat 3 to a certain value or less by limiting the moving speed of the speed adjustment target code (in the example shown in FIG. 1, the lifting / lowering codes C1, C2, and C3).

  If the speed adjusting device 6 is not installed, if the hand is released from the lifting / lowering cords C1, C2, C3, etc. that are suspended from the cord outlet 14 during the lowering operation, the operation of the stopper device 15 is canceled and the weight of the bottom rail 4 and the slat 3 , And the falling sound at that time and the collision sound with the floor surface of the bottom rail 4 cause discomfort to the operator. For this reason, by providing the speed adjusting device 6 as in the present embodiment, it is possible to decelerate only when descending and to apply a braking force to decelerate and descend.

  It should be noted that if a constant braking force is applied even when the slat 3 is raised, the guidance load at that time will increase, and the constant braking force will always work, which may cause deterioration of the code. This is also not preferable.

  For this reason, the speed adjusting device 6 generates a braking force only in one direction of movement of the speed adjustment target code (elevating cords C1, C2, C3 in the example shown in FIG. 1) and moves in the other direction. The load of the code at the time can be reduced.

  The speed adjusting device 6 will be described later in detail for each embodiment. A pair of rollers sandwiches the lifting / lowering cords C1, C2 and C3, and the lifting / lowering cords C1, C2 and C3 are moved according to the moving direction of the lifting / lowering cords C1, C2, C3. A brake unit is provided that switches between a narrow pressure state and a non-narrow pressure state for C2 and C3, and generates a braking torque for the rotation shaft (roller shaft) of one or both of the pair of rollers. (In the embodiment described later, the brake portion is provided only for one of the roller shafts).

  When the slat 3 is lowered, the speed adjusting device 6 generates a braking force that causes high friction with respect to the movement of the lifting / lowering cord so that it can be smoothly and appropriately performed by a brake portion provided in the speed adjusting device 6. When the slat 3 is lifted, it can be smoothly operated so that the generation of the braking force that causes low friction with respect to the movement of the lifting / lowering cord is substantially zero.

  In particular, in the speed adjusting device 6 according to the present invention, when the roller shaft provided with the brake portion rotates at a speed exceeding a set speed for generating a predetermined braking force, that is, when an excessive speed rotation occurs. An overload limiting mechanism is provided that suppresses the rotation of the roller shaft in conjunction with the brake shaft of the brake unit. Hereinafter, as a suitable example in which an overload limiting mechanism is provided without increasing the size of the speed adjusting device 6, the speed adjusting device 6 of each embodiment according to the present invention will be described in order.

[Speed Adjustment Device of Example 1]
FIG. 2 is a perspective view of the speed adjustment device 6 according to the first embodiment of the present invention. FIG. 3 is an exploded perspective view of the speed adjusting device 6 according to the first embodiment of the present invention. As shown in FIGS. 2 and 3, the speed adjusting device 6 according to the first embodiment of the present invention includes an alignment member 60, a case 61, a slider 62, a coil spring SP, an idle roller 63, a drive roller 64, and a carrier with internal teeth. 65, an annular plate 66, a weight holder 67 with sun gear, a weight 68, and a base 69. The internal toothed carrier 65, the annular plate 66, the weight holder 67 with sun gear, and the weight 68 are configured as a brake portion 6 a that generates a braking torque with respect to the rotation of the drive roller 64.

  First, the alignment member 60 is formed in a substantially square box shape having a hollow portion 601 surrounded by four vertical walls and penetrating vertically, and the slider 601 located above the case 61 is accommodated in the hollow portion 601. The part 611 is engaged through and placed on the upper part of the brake accommodating part 612 located at the lower part of the case 61. In each vertical wall facing the left and right direction of the alignment member 60, cord insertion holes 602 and 603 each having a substantially square hole shape are provided. In the state in which the alignment member 60 is placed on the case 61, the cord insertion holes 602 and 603 are surely separated by the cord insertion holes 602 and 603 so that the cords are not entangled with each other. As shown in FIG. 2, the lifting / lowering cords C1, C2, C3 are guided with respect to the cord insertion holes 614 provided in the left and right walls of the slider accommodating portion 611 of the case 61. In addition, the arrangement | sequence which isolate | separates and guides the raising / lowering code | cord | chord C1, C2, C3 to the code | cord | chord insertion hole 614 using the code | cord | chord insertion hole 602,603 need not be limited to the example to show in figure, but can be changed by a use.

  The case 61 has a box-like shape in which a slider accommodating portion 611 that accommodates the slider 62 and the coil spring SP and a brake accommodating portion 612 that accommodates the brake portion 6a are connected to each other and the lower portion is opened. An inner peripheral gear 612a is formed on the inner peripheral wall of the brake accommodating portion 612 of the case 61 (see FIG. 4). Further, the lower end of the brake accommodating portion 612 in the case 61 is formed in a substantially square plate shape having fitting receiving portions 615 at the four corners, and is also formed by a base 69 formed in a substantially square plate shape having fitting protrusion pieces 693 at the four corners. The respective fitting receiving portions 615 of the case 61 and the respective fitting projections 693 of the base 69 are fitted and covered. As described above, the case 61 is provided with the cord insertion holes 614 through which the lifting / lowering cords C 1, C 2, and C 3 can be inserted in the respective wall portions in the left-right direction of the slider accommodating portion 611.

  By the way, the upper surface of the slider accommodating portion 611 in the case 61 is formed with a C-shaped groove 613 extending substantially in the left-right direction and slightly bent in the front-rear direction, and each groove in the C-shaped groove 613 corresponds to the slider 62. The roller shafts 631 and 641 on the upper side of the idle roller 63 and the drive roller 64 accommodated in the shaft are supported so as to be movable along the groove shape.

  On the other hand, the slider 62 is formed in a substantially square box shape having a hollow portion 620 that is surrounded by the left and right vertical walls, the top wall, and the bottom wall and penetrates in the front-rear direction, and includes a roller portion 632 of the idle roller 63 and a drive roller. 64 roller portions 642 are accommodated in the hollow portion 620, and the roller shafts 631 and 641 above the roller portions 632 and 642 are formed by a pair of ceiling wall grooves 621 formed to extend in the front-rear direction on the ceiling wall. A pair of lower wall grooves that are pivotally supported and are formed so as to extend in the front-rear direction on the bottom wall in parallel with the pair of top wall grooves 621 for the lower roller shafts 631 and 641 of the roller portions 632 and 642, respectively. 622 supports the shaft. As a result, the slider 62 supports the idle roller 63 and the drive roller 64 so as to be movable in the front-rear direction, which is a direction intersecting with the above-described groove-shaped groove 613.

  When the slider 62 is housed in the slider housing portion 611 of the case 61, the other end of the coil spring SP that engages one end with the inner wall of the slider housing portion 611 engages with the engagement recess 623 of the slider 62. The slider 62 is always relatively moved in the left-right direction (relative slide) in a state where the slider 62 is urged in one direction (the left direction in the drawing) in the slider accommodating portion 611 in the case 61 by the coil spring SP by the compression spring. Movement).

  In addition, cord insertion holes 624 are formed in the left and right vertical walls of the slider 62, respectively. Therefore, in a state where the slider 62 is accommodated in the slider accommodating portion 611 in the case 61, the cord insertion hole 614 in the case 61 and the cord insertion hole 624 in the slider 62 are relatively displaced from each other in the left / right / front / rear / up / down direction. The lift cords C1, C2, C3 inserted through the cord insertion hole 624 of the slider 62 through the cord insertion hole 614 in the case 61 are all in the slider 62 and the roller of the idle roller 63. It will be in the state pinched | interposed into the roller part 642 of the part 632 and the drive roller 64. FIG.

  The idle roller 63 and the drive roller 64 that are slidably supported by the slider 62 cooperate with the C-shaped groove 613 of the case 61 to move up and down according to the moving direction of the lifting cords C1, C2, and C3. The state of narrow pressure / non-narrow pressure for the codes C1, C2, C3 can be switched (details will be described later).

  The idle roller 63 has a roller portion 632 having a roller shaft 631 as an axis. The roller shaft 631 above the roller portion 632 is pivotally supported by one of the top wall groove 621 of the slider 62 and the groove-shaped groove 613 of the case 61, and the roller shaft 631 below the roller portion 632 is a slider. After being pivotally supported by one bottom wall groove 622 of 62, each of these members does not interfere with the internal gear carrier 65, the annular plate 66, the sun gear weight holder 67 and the weight 68 which are configured as the brake portion 6a. And is supported by one groove of a C-shaped groove 692 provided in a raised portion 691 that rises in a circular shape substantially at the center of the base 69.

  The drive roller 64 is a member provided with the overload limiting mechanism according to the present invention, but the overload limiting mechanism will be described in detail later, and here, only the structural portion that functions as the speed adjusting device 6 will be described. To do.

  The drive roller 64 has a roller shaft 642 having a roller shaft 641 as an axis, and a gear shaft having an upper end connected by a serration structure that can be coaxially transmitted and separated at the lower end of the roller shaft 641. Pinion gear 644, shaft holding portion 643 for holding the respective shafts of roller portion 642 and pinion gear 644 (roller shaft 641 and the gear shaft), and the respective shafts of roller portion 642 and pinion gear 644 (roller shaft 641 and the gear shaft) ), And a support shaft 645 having a shaft support portion that supports the lower end portion of the gear shaft of the pinion gear 644.

  The roller shaft 641 above the roller portion 642 of the drive roller 64 is pivotally supported by the other top wall groove 621 of the slider 62 and the other groove 613 of the case 61, and the roller shaft below the roller portion 642. 641 is pivotally supported by the other bottom wall groove 622 of the slider 62. The shaft holding portion 643 of the drive roller 64 is positioned below the slider 62, and the pinion gear 644 below the shaft holding portion 643 meshes with an internal gear 652 formed on the inner peripheral surface of the inner toothed carrier 65. Is done. A support shaft 645 having a shaft support portion that supports the lower end portion of the gear shaft of the pinion gear 644 includes an internally toothed carrier 65 configured as a brake portion 6a, an annular plate 66, a weight holder 67 with a sun gear, and a weight 68. Without interfering, it is supported by the other groove of the C-shaped groove 692 provided in the raised portion 691 that rises in a circular shape at the approximate center of the base 69 through the hollow portion of each member.

  In this example, a knurl is engraved on the peripheral surface of the roller portion 642 of the drive roller 64, and a knurl is not engraved on the peripheral surface of the roller portion 632 of the idle roller 63. Knurls may also be engraved on the peripheral surface of 632. In addition, washers (not shown) can be appropriately interposed between the shaft portions of the drive roller 64 and the idle roller 63.

  In this example, the brake part 6a has a centrifugal brake structure in which the brake amount can be adjusted in multiple stages, and is constituted by an internal toothed carrier 65, an annular plate 66, a weight holder 67 with a sun gear, and a weight 68. In particular, the brake unit 6a is configured to have a braking torque amplifying function based on the rotation of the pinion gear 644 and a braking torque adjusting function that can adjust the braking torque by the centrifugal brake in multiple stages.

  The internally toothed carrier 65 is provided with a cylindrical portion 654 having a hollow portion at the center of a substantially disc-shaped carrier body 651 and protruding downward, and an internal gear 652 is formed on the inner peripheral surface of the cylindrical portion 654. . The internal gear 652 is meshed with the pinion gear 644 of the drive roller 64. A plurality (four in this example) of planetary gears 653 that are symmetrically arranged at predetermined intervals on the outer periphery of the cylindrical portion 654 are rotatable on the lower surface of the substantially disc-shaped carrier body 651 of the carrier 65 with internal teeth. It is supported by.

  Each planetary gear 653 meshes with the sun gear 672 in the weight holder 67 with sun gear and the inner peripheral gear 612a formed on the inner peripheral wall of the brake accommodating portion 612 of the case 61 (see FIG. 4). ).

  Then, the inner peripheral surface of the cylindrical portion 654 protruding downward from the internal toothed carrier 65 is engaged with the outer peripheral wall of the raised portion 691 that protrudes in a circular shape at the approximate center of the base 69 below the internal gear 652. It is supported rotatably and can rotate (revolve) with the central portion of the internal gear 652 as the central axis. Accordingly, the rotation of the pinion gear 644 of the drive roller 64 is transmitted to the internal gear 652, whereby the internal toothed carrier 65 is rotated, and accordingly, each of the internal geared carrier 65 is rotatably supported by the carrier body 651. As the planetary gear 653 rotates, the rotation of the pinion gear 644 can be transmitted to the weight holder 67 with sun gear.

  In the weight holder 67 with sun gear, eight projecting pieces 673 projecting radially from the lower outer periphery of the substantially cylindrical holder main body 671 are formed in this example, and the upper approximately cylindrical shape on which the projecting pieces 673 are formed. A sun gear 672 is formed on the outer peripheral surface of the holder body 671. The inner peripheral surface of the holder main body 671 is rotatably supported by engaging with the outer peripheral surface of the cylindrical portion 654 projecting downward from the internal toothed carrier 65, and rotates (revolves) around the central portion of the sun gear 672. It is possible to do.

(Brake torque amplification function)
The centrifugal force increases as the rotation radius increases, the rotation speed increases, and the mass (weight and number of weights 68 itself) increases. However, in the speed adjustment device 6 of the first embodiment, as shown in FIG. The rotation of the pinion gear 644 is transmitted through the internal geared carrier 65 to the weight holder 67 with sun gear while increasing the rotation radius, so that an effect of amplifying the braking torque is generated. Thus, it is possible to reduce the size of the one speed adjusting device 6 and to generate an efficient braking force.

  In this example formed so as to project radially from the lower outer periphery of the substantially cylindrical holder body 671, the eight projecting pieces 673 form eight concave portions, and each of the eight concave portions has a substantially trapezoidal plate shape. Accordingly, the eight projecting pieces 673 can hold the weights 68 in cooperation with the inner wall of the brake accommodating portion 612 in the case 61.

(Brake torque adjustment function)
That is, the speed adjusting device 6 according to the first embodiment can adjust the number of the weights 68 to be adjusted, thereby adjusting the braking torque due to the centrifugal brake applied to the pinion gear 644. In this example, a total of nine adjustments can be made. By increasing the maximum number of weights 68 that can be arranged by the weight holder 67 with sun gear (increase in the number of protruding pieces 673), it is possible to adjust the braking torque by finer multistage centrifugal braking.

  An annular plate 66 is interposed between the carrier 65 with internal teeth and the weight holder 67 with sun gear. The annular plate 66 is arranged at the center of the disk shape slightly smaller than the outer peripheral diameter of the holder main body 671 including the tips of the eight protruding pieces 673 in the weight holder 67 with sun gear, and the sun gear 672 in the weight holder 67 with sun gear. It has a shape having a hollow portion that is slightly larger in diameter than the outer peripheral diameter of the holder main body 671 and includes the holder main body 671. For this reason, the annular plate 66 prevents the planetary gears 653 from tilting when the internal geared carrier 65 and the sun geared weight holder 67 are engaged, and the planetary gears 653 and the weights 68 interfere with each other. Has a function to prevent.

(Code movement detection function)
Further, in the speed adjusting device 6 of the first embodiment, the pair of roller portions 632 and 642 including the idle roller 63 and the drive roller 64 that are slidably supported by the slider 62 with respect to the case 61 are Since each axis is guided by 613 (further, the groove 692 of the base 69), it is possible to detect the presence / absence and movement direction of the lifting / lowering cords C1, C2, C3. When the elevating cords C1, C2, C3 move in one direction, the pair of roller portions 632, 642 narrows the elevating cords C1, C2, C3, and the elevating cords C1, C2, C3 move in the other direction. In this case, the narrowing state by the pair of roller parts 632 and 642 is relaxed (as non-narrowing pressure) so that the lifting cords C1, C2 and C3 are sandwiched.

  That is, in the example of this embodiment, a pair of roller portions 632 and 642 by the idle roller 63 and the drive roller 64 are pivotally supported by the top wall groove 621 and the bottom wall groove 622 of the slider 62, respectively, and As shown in FIG. 5 (a), the lifting / lowering cords C1, C2, C3 are directed to the left (bottom rail). 4, the slider 62 also slides in the same direction, and is guided so that the distance between the pair of roller portions 632 and 642 is reduced, so that the pair of roller portions 632 and 642 is moved. The lift cords C1, C2, and C3 are sandwiched by narrowing the pressure.

  On the other hand, as shown in FIG. 5B, when the elevating cords C1, C2, and C3 move in the right direction (operation side), the slider 62 slides in the right direction (operation side), and a pair of rollers By guiding the distance between the parts 632 and 642 to be separated, the narrow pressure state by the pair of roller parts 632 and 642 is relaxed (as a non-narrow pressure) and the lifting cords C1, C2 and C3 are sandwiched. . Accordingly, in the example shown in FIGS. 5A and 5B, the slider 62 moves relative to the case 61 by Δd.

  Therefore, the operation of the speed adjusting device 6 of the first embodiment will be described with reference to FIG. In FIG. 6, in order to improve the understanding of the operation, the speed adjusting device 6 is simply illustrated in an arrangement corresponding to the plan view shown in FIG. In addition, the arrangement | positioning and position of the raising / lowering cords C1, C2, and C3, and the arrangement angle of the speed adjusting device 6 are arbitrary, for example, arranged inclining up and down and front and rear.

(When slat descends)
First, when the slat 3 is lowered by the movement of the lifting / lowering cords C1, C2, and C3 as shown in FIG. 6 (a), the movement of the lifting / lowering cords C1, C2, and C3 is performed as shown in FIG. 5 (a). As a result, the slider 62 also slides in the same direction and is guided so that the distance between the pair of roller portions 632 and 642 is narrowed, so that the pair of roller portions 632 and 642 is narrowed and the lift cords C1 and C2 , C3, and a narrow pressure state in which the moving speed in one direction of the lifting / lowering cords C1, C2, C3 can be limited.

  As a result, as shown in FIG. 6A, the pulling operation of the lifting / lowering cords C1, C2, C3 (or the operation cord 7 and the cord equalizer 8) is stopped, the operation of the stopper device 15 is released, and the slat 3 is lowered by its own weight. When the distance between the pair of roller portions 632 and 642 in the speed adjusting device 6 is close, the pressure adjusting device 6 is in a narrow pressure state, that is, in a high friction state, generating a braking force and smoothly moving down the slat 3 at an appropriate speed. It is realized to do in.

(When slat rises)
On the other hand, when the slat 3 is raised by the movement of the lifting / lowering cords C1, C2, and C3 as shown in FIG. 6 (b), it is caused by the movement of the lifting / lowering cords C1, C2, and C3 as shown in FIG. 5 (b). Then, the narrow pressure state by the pair of roller parts 632 and 642 is relaxed (as a non-narrow pressure) so that the lifting cords C1, C2, and C3 are sandwiched.

  Accordingly, as shown in FIG. 6 (b), when the slat 3 is lifted based on the pulling operation of the lifting / lowering cords C1, C2, C3 (or the operation cord 7 or the cord equalizer 8), the pair of roller portions in the speed adjusting device 6 The distance between 632 and 642 is separated to be in a released state, that is, a non-narrow pressure state, and the slat 3 is smoothly raised.

  This causes a braking force to be generated only in one direction of movement of the speed adjustment target code (lifting code C1, C2, C3 in this example), and also reduces the load of the code during movement in the other direction. Therefore, it is possible to suppress an increase in code deterioration and deterioration in operability.

(Overload limit function)
By the way, in the speed adjusting device 6 of the first embodiment, in addition to the braking torque amplification function, the braking torque adjustment function, and the cord movement detection function described above, the drive roller 64 is different from the conventional technique in FIG. A mechanism for realizing the overload limiting function as shown is provided.

  That is, as in the comparative example shown in FIG. 7B, a drive roller 64a having a roller portion 642 and a pinion gear 644 on a roller shaft 641 is provided instead of the drive roller 64 shown in FIGS. The above-described braking torque amplification function, braking torque adjustment function, and cord movement detection function can be realized. However, when the drive roller 64a rotates excessively on the roller shaft 641, the roller shaft 641 and the brake unit 6a An overload is applied, and there is a possibility that damage or wear of the cords (the lifting cords C1, C2, and C3 in this example) and the brake portion 6a may occur. Therefore, in the speed adjusting device 6 of the first embodiment, the drive roller 64 is provided with an overload limiting mechanism as shown in FIG.

  More specifically, as shown in FIG. 7A, the drive roller 64 in the speed adjustment device 6 of the first embodiment includes a roller portion 642 having a roller shaft 641 as an axis and a lower end portion of the roller shaft 641. 641a and a pinion gear 644 having a gear shaft 644a having an upper end portion 644b coupled in a serration structure that can be transmitted and separated on the same axis, and a roller portion 642 and a pinion gear 644 (roller shaft 641 and gear shaft 644a). ) And a compression spring 645b that biases the lower end portion 641a of the roller shaft 641 and the upper end portion 644b of the gear shaft 644a to be coupled by the spring accommodating portion 645b, and the lower end of the gear shaft 644a. A support shaft 645 having a shaft support portion 645a for supporting the portion.

  The support shaft 645 is attached to a compression spring 645b that urges the roller shaft 641 to connect the lower end portion 641a of the roller shaft 641 and the upper end portion 644b of the gear shaft 644a, and has any shape that supports the lower end portion of the gear shaft 644a. The support shaft 645 may not be rotatable relative to the gear shaft 644a or may be rotatable relative to the gear shaft 644a.

  The shaft surfaces of the lower end portion 641a and the upper end portion 644b are formed with meshing teeth (tooth sizes) that mesh with each other toward the shaft circumferential surface from the shaft center. The lower end portion 641a of the roller shaft 641 and the upper end portion 644b of the gear shaft 644a constitute a serration structure that can be transmitted and separated from each other. However, the serration engagement that can be used in the present invention is not necessarily limited to such a structure that can be transmitted and separated by the contact friction between the opposed shaft end surfaces. Serration engagement that engages so as to be able to be transmitted and separated by friction or serration engagement that engages so as to be able to be transmitted and separated by contact friction between one shaft peripheral surface and the other shaft end surface may be employed.

  As shown in the operation diagram illustrated as a normal time (at the time of non-overload limitation) in FIG. 8A, the drive roller 64 in the speed adjusting device 6 of the first embodiment is driven by the roller shaft 641 by the urging force of the compression spring 645b. Since the upper end portion 644b of the gear shaft 644a is pressed against the lower end portion 641a, the roller shaft 641 rotates at a rotational speed Va within a set speed (speed threshold value Vth) that generates a predetermined braking force. The lower end portion 641a of the roller shaft 641 is connected to the upper end portion 644b of the gear shaft 644a so that the rotation of the shaft 641 is transmitted to the gear shaft 644a at the same speed Va.

  On the other hand, as shown in the operation diagram illustrated as an overload limit in FIG. 8B, the drive roller 64 in the speed adjusting device 6 of the first embodiment is set at a speed at which the roller shaft 641 generates a predetermined braking force. When rotating at a speed Va exceeding (speed threshold value Vth), that is, when excessive speed rotation occurs, the meshing teeth of the lower end portion 641a of the roller shaft 641 and the upper end portion 644b of the gear shaft 644a slip and mesh with each other. As a result, the rotation of the roller shaft 641 is not transmitted to the gear shaft 644a at the same speed. For this reason, when the roller shaft 641 rotates at the rotational speed Va exceeding the speed threshold Vth, the gear shaft 644a is always restrained to the rotational speed Vb below the speed threshold Vth. The rotation of the pinion gear 644 serving as the shaft core is suppressed.

  Accordingly, the serration structure suppresses the rotation of the roller shaft 641 from being interlocked with the gear shaft 644a serving as the brake shaft of the brake portion 6a based on the set speed (speed threshold Vth) that generates a predetermined braking force. Functions as an overload limiting mechanism.

  Thus, for example, in the horizontal blind according to this embodiment shown in FIG. 9, when an excessive external force is generated on the bottom rail 4, the roller shaft 641 of the drive roller 64 in the speed adjustment device 6 of Example 1 is controlled to a predetermined level. The gear shaft 644a always rotates at a speed Va exceeding the set speed (speed threshold value Vth) for generating power, that is, even if an excessive speed rotation occurs, the gear shaft 644a is always restrained to the rotational speed Vb below the speed threshold value Vth. Thus, the rotation of the pinion gear 644 with the gear shaft 644a as an axis is suppressed, and damage to each member or wear of the cord (the lifting cords C1, C2, C3 in this example) and the brake portion 6a can be prevented.

[Speed Adjustment Device of Example 2]
FIG. 10A is a diagram showing a schematic configuration of a drive roller 64 having an overload limiting mechanism in the speed adjusting device 6 according to the second embodiment of the present invention, and FIGS. 10B and 10C are AA views thereof. It is a figure which shows the general | schematic operation | movement at the time of a normal operation | movement at the time of a cross section, and an overload limit, respectively. In addition, the same reference number is attached | subjected to the component similar to Example 1. FIG.

  The speed adjusting device 6 according to the second embodiment can be configured in substantially the same manner as the speed adjusting device 6 according to the first embodiment shown in FIGS. 2 and 3 except that the structure of the drive roller 64 is different. For this reason, with reference to FIG. 10, the drive roller 64 which concerns on the speed adjustment apparatus 6 of Example 2 is demonstrated.

  In the speed adjusting device 6 of the second embodiment, as in the first embodiment, in addition to the braking torque amplification function, the braking torque adjustment function, and the cord movement detection function described above, unlike the conventional technique, A mechanism for realizing an overload limiting function as shown in FIG.

(Overload limit function)
More specifically, as shown in FIG. 10A, the drive roller 64 in the speed adjusting device 6 of the second embodiment includes a roller portion 642 having a roller shaft 641 as an axis and a lower end portion of the roller shaft 641. 641a is a square shaft, and a pinion gear 644 whose axis is a gear shaft 644a having a square shaft upper end portion 644b coaxially separated from the roller shaft 641, and each shaft (roller shaft 641) of the roller portion 642 and the pinion gear 644. And a shaft holding portion 643 for allowing elastic deformation and releasing the interlocked rotation of the roller shaft 641 and the gear shaft 644a when the rotational speed of the roller shaft 641 exceeds the speed threshold Vth. Prepare.

  In the present embodiment, the gear shaft 644a below the pinion gear 644 is pivotally supported by a corresponding groove of a C-shaped groove 692 provided in a raised portion 691 that rises in a circular shape substantially at the center of the base 69 shown in FIG. .

  In this embodiment, the shaft holding portion 643 holds the shafts of the roller portion 642 and the pinion gear 644 (roller shaft 641 and gear shaft 644a), and elastic deformation occurs when the rotational speed of the roller shaft 641 exceeds the speed threshold value Vth. It is constituted by a buffer member such as an acceptable rubber material. In particular, the shaft holding portion 643 is surface-engaged with the lower end portion 641a (square shaft) of the roller shaft 641 as shown in the section AA ′ in FIGS. 10B and 10C, and the gear shaft 644a. A square hole 643a that is in surface engagement with the upper end 644b (square axis) is formed.

  Accordingly, as shown in the operation diagram of the AA ′ cross-section illustrated as a normal time (non-overload limit) in FIG. 10B, the drive roller 64 in the speed adjustment device 6 of the second embodiment is a roller shaft 641. Is the rotation speed Va within a set speed (speed threshold Vth) for generating a predetermined braking force, the lower end portion 641a (square axis) of the roller shaft 641 is a surface of the shaft holding portion 643 with the square hole 643a. By maintaining the engagement, the shaft holding portion 643 also rotates at the same speed, and the upper end portion 644b (square shaft) of the gear shaft 644a maintains the surface engagement with the square hole 643a of the shaft holding portion 643. The rotation of the roller shaft 641 is transmitted to the gear shaft 644a at the same speed Va, and the pinion gear 644 rotates in conjunction with it.

  On the other hand, as shown in the operation diagram of the AA ′ cross section illustrated as an example when the overload is limited in FIG. 10C, the drive roller 64 in the speed adjusting device 6 of the second embodiment has the roller shaft 641 having a predetermined control. When rotating at a speed Va exceeding a set speed (speed threshold Vth) for generating power, that is, when excessive speed rotation occurs, the square hole 643a of the shaft holding portion 643 is elastically deformed, and the lower end portion of the roller shaft 641 641a (square shaft) is in a state where the surface engagement with the rectangular hole 643a of the shaft holding portion 643 is impaired (or the upper end portion 644b (square shaft) of the gear shaft 644a is connected to the square hole 643a of the shaft holding portion 643. The rotation of the roller shaft 641 is not transmitted to the gear shaft 644a at the same speed. For this reason, when the roller shaft 641 rotates at the rotational speed Va exceeding the speed threshold Vth, the gear shaft 644a is always restrained to the rotational speed Vb below the speed threshold Vth. The rotation of the pinion gear 644 serving as the shaft core is suppressed.

  Therefore, the structure in which the roller shaft 641 and the gear shaft 644a are held by the shaft holding portion 643 configured by the buffer member is based on the set speed (speed threshold Vth) that generates a predetermined braking force. It functions as an overload limiting mechanism that suppresses the rotation of the gear shaft 644a that is the brake shaft of the brake portion 6a.

  In the example shown in FIG. 10, the square hole 643a of the shaft holding portion 643 is surface-engaged with both the lower end 641a (square shaft) of the roller shaft 641 and the upper end 644b (square shaft) of the gear shaft 644a. However, it has a structure that allows surface engagement with either one of the lower end portion 641a (square shaft) of the roller shaft 641 and the upper end portion 644b (square shaft) of the gear shaft 644a. May be fixed to the square hole 643a.

  Accordingly, in the horizontal blind according to the embodiment illustrated in FIG. 9 described above, when an excessive external force is generated on the bottom rail 4, the roller shaft 641 of the drive roller 64 in the speed adjusting device 6 according to the second embodiment is predetermined. The gear shaft 644a is always restrained to a rotational speed Vb that is equal to or lower than the speed threshold Vth even if it rotates at a speed Va that exceeds a set speed (speed threshold Vth) that generates a braking force of Thus, the rotation of the pinion gear 644 centering on the gear shaft 644a is suppressed, and it is possible to prevent breakage of each member or wear of the cord (in this example, the lifting / lowering cords C1, C2, C3) and the brake portion 6a. it can.

[Speed Adjustment Device of Example 3]
FIG. 11A is a diagram showing a schematic configuration of a drive roller 64 having an overload limiting mechanism in the speed adjusting device 6 according to the third embodiment of the present invention, and FIGS. 11B and 11C are AA views thereof. It is a figure which shows the general | schematic operation | movement at the time of a normal operation | movement at the time of a cross section, and an overload limit, respectively. In addition, the same reference number is attached | subjected to the component similar to Example 1. FIG.

  The speed adjusting device 6 of the third embodiment is configured as a modification of the second embodiment, and is substantially the same as the speed adjusting device 6 of the first embodiment shown in FIGS. 2 and 3 except that the structure of the drive roller 64 is different. Can be configured. For this reason, with reference to FIG. 11, the drive roller 64 which concerns on the speed adjustment apparatus 6 of Example 3 is demonstrated.

  In the speed adjusting device 6 according to the third embodiment, in the same manner as the first embodiment, in addition to the above-described braking torque amplification function, braking torque adjustment function, and cord movement detection function, the drive roller 64 is different from the conventional technique. A mechanism for realizing an overload limiting function as shown in FIG.

(Overload limit function)
More specifically, as shown in FIG. 11A, the drive roller 64 in the speed adjusting device 6 of the third embodiment includes a roller portion 642 having a roller shaft 641 as an axis and a lower end portion of the roller shaft 641. 641a is a square shaft, a pinion gear 644 having a cylindrical shaft upper end portion 644b coaxially separated from the roller shaft 641 and a shaft shaft 644a having an axial center, and a shaft holding fixedly accommodated in the cylindrical upper end portion 644b Part 643, which holds the respective axes of the roller part 642 and the pinion gear 644 (roller shaft 641 and gear shaft 644a), and allows the elastic deformation when the rotational speed of the roller shaft 641 exceeds the speed threshold Vth, A shaft holding portion 643 that releases the interlocking rotation of the roller shaft 641 and the gear shaft 644a.

  In the present embodiment, the gear shaft 644a below the pinion gear 644 is pivotally supported by a corresponding groove of a C-shaped groove 692 provided in a raised portion 691 that rises in a circular shape substantially at the center of the base 69 shown in FIG. .

  In the present embodiment, the shaft holding portion 643 fixedly accommodated in the cylindrical upper end portion 644b of the gear shaft 644a in the pinion gear 644 holds the shafts of the roller portion 642 and the pinion gear 644 (roller shaft 641 and gear shaft 644a). When the rotational speed of the roller shaft 641 exceeds the speed threshold value Vth, the roller shaft 641 is constituted by a buffer member such as a rubber material that allows elastic deformation. In particular, as shown in the AA ′ cross section in FIGS. 11B and 11C, the shaft holding portion 643 fixedly accommodated in the cylindrical upper end portion 644b of the gear shaft 644a of the pinion gear 644 is provided on the roller shaft 641. A square hole 643a that engages with the lower end portion 641a (square axis) is formed.

  Therefore, as shown in the operation diagram of the AA ′ cross section illustrated as a normal time (when the non-overload is limited) in FIG. 11B, the drive roller 64 in the speed adjusting device 6 of the third embodiment is a roller shaft 641. Is the rotation speed Va within a set speed (speed threshold Vth) for generating a predetermined braking force, the lower end portion 641a (square axis) of the roller shaft 641 is a surface of the shaft holding portion 643 with the square hole 643a. By maintaining the engagement, the rotation of the roller shaft 641 is transmitted to the gear shaft 644a at the same speed Va, and the pinion gear 644 rotates in conjunction.

  On the other hand, as shown in the operation diagram of the AA ′ cross section illustrated as an example when the overload is limited in FIG. 11C, the drive roller 64 in the speed adjustment device 6 of the third embodiment has the roller shaft 641 having a predetermined restriction. When rotating at a speed Va exceeding a set speed (speed threshold Vth) for generating power, that is, when excessive speed rotation occurs, the square hole 643a of the shaft holding portion 643 is elastically deformed, and the lower end portion of the roller shaft 641 641a (square shaft) is in a state where the surface engagement with the square hole 643a of the shaft holding portion 643 is impaired, and the rotation of the roller shaft 641 is not transmitted to the gear shaft 644a at the same speed. For this reason, when the roller shaft 641 rotates at the rotational speed Va exceeding the speed threshold Vth, the gear shaft 644a is always restrained to the rotational speed Vb below the speed threshold Vth. The rotation of the pinion gear 644 serving as the shaft core is suppressed.

  Therefore, the structure in which the roller shaft 641 and the gear shaft 644a are held by the shaft holding portion 643 configured by the buffer member is based on the set speed (speed threshold Vth) that generates a predetermined braking force. It functions as an overload limiting mechanism that suppresses the rotation of the gear shaft 644a that is the brake shaft of the brake portion 6a.

  In the example shown in FIG. 11, the square hole 643 a of the shaft holding portion 643 fixedly accommodated in the cylindrical upper end portion 644 b of the gear shaft 644 a of the pinion gear 644 is connected to the lower end portion 641 a (square shaft) of the roller shaft 641. Although the example which enables a surface engagement was demonstrated, it is good also as a structure opposite to the structure shown to Fig.11 (a) as a shape of the lower end part 641a of the roller shaft 641 and the upper end part 644b of the gear shaft 644a.

  Accordingly, in the horizontal blind according to the embodiment illustrated in FIG. 9 described above, when an excessive external force is generated on the bottom rail 4, the roller shaft 641 of the drive roller 64 in the speed adjusting device 6 according to the third embodiment is predetermined. The gear shaft 644a is always restrained to a rotational speed Vb that is equal to or lower than the speed threshold Vth even if it rotates at a speed Va that exceeds a set speed (speed threshold Vth) that generates a braking force of Thus, the rotation of the pinion gear 644 centering on the gear shaft 644a is suppressed, and it is possible to prevent breakage of each member or wear of the cord (in this example, the lifting / lowering cords C1, C2, C3) and the brake portion 6a. it can.

[Speed Adjustment Device of Example 4]
FIG. 12A is a diagram showing a schematic configuration of a drive roller 64 having an overload limiting mechanism in the speed adjusting device 6 of the fourth embodiment according to the present invention, and FIGS. 12B and 12C are AA views thereof. It is a figure which shows the general | schematic operation | movement at the time of a normal operation | movement at the time of a cross section, and an overload limit, respectively. In addition, the same reference number is attached | subjected to the component similar to Example 1. FIG.

  The speed adjusting device 6 according to the fourth embodiment can be configured in substantially the same manner as the speed adjusting device 6 according to the first embodiment shown in FIGS. 2 and 3 except that the structure of the drive roller 64 is different. For this reason, with reference to FIG. 11, the drive roller 64 which concerns on the speed adjustment apparatus 6 of Example 4 is demonstrated.

  In the speed adjusting device 6 according to the fourth embodiment, as in the first embodiment, in addition to the braking torque amplification function, the braking torque adjustment function, and the cord movement detection function described above, unlike the conventional technique, A mechanism for realizing an overload limiting function as shown in FIG.

(Overload limit function)
More specifically, as shown in FIG. 12A, the drive roller 64 in the speed adjusting device 6 of the fourth embodiment includes a roller portion 642 having a roller shaft 641 as an axis and a lower end portion of the roller shaft 641. 641a is a round convex shaft, and a gear shaft 644a having a cylindrical upper end portion 644b that is coaxially separated from the roller shaft 641 and engages with a lower end portion 641a (round convex shaft) so as to be rotatable relative to the roller shaft 641. One end 643c can be engaged with the pinion gear 644 and the protrusion 641b partially protruding outward on the peripheral surface of the roller shaft 641, and the other end of the protrusion 644c partially protruding outward on the peripheral surface of the gear shaft 644a. 643d is a shaft holding portion 643 configured by a clutch spring by a compression spring that can engage with each other, and each shaft (roller shaft 6) of the roller portion 642 and the pinion gear 644 is provided. 1 and the gear shaft 644a), and when the rotational speed of the roller shaft 641 exceeds the speed threshold value Vth, the engagement of the one end 643c or the other end 643d of the clutch spring is disengaged, and the roller shaft 641 and the gear shaft 644a A shaft holding portion 643 for releasing the interlocking rotation.

  In the present embodiment, the gear shaft 644a below the pinion gear 644 is pivotally supported by a corresponding groove of a C-shaped groove 692 provided in a raised portion 691 that rises in a circular shape substantially at the center of the base 69 shown in FIG. .

  In this embodiment, the shaft holding portion 643 configured by a clutch spring holds the shafts of the roller portion 642 and the pinion gear 644 (the roller shaft 641 and the gear shaft 644a), and the rotational speed of the roller shaft 641 is the speed threshold Vth. Is exceeded, the engagement of the one end 643c or the other end 643d of the clutch spring is disengaged. In particular, as shown in the section AA ′ in FIGS. 12B and 12C, the shaft holding portion 643 constituted by the clutch spring is a protruding portion that partially protrudes outward on the peripheral surface of the roller shaft 641. One end 643c is engageable with 641b, and a clutch spring is formed by a compression spring that allows the other end 643d to be engaged with a protrusion 644c partially protruding outward on the peripheral surface of the gear shaft 644a.

  Therefore, as shown in the operation diagram of the AA ′ cross section illustrated as a normal time (non-overload limit time) in FIG. Is rotated within a set speed (speed threshold value Vth) at which a predetermined braking force is generated, the one end 643c of the shaft holding portion 643 (clutch spring) is engaged with the protrusion 641b of the roller shaft 641. By maintaining the state and the state in which the other end 643d of the shaft holding portion 643 (clutch spring) is engaged with the protrusion 644c of the gear shaft 644a, the rotation of the roller shaft 641 is transmitted to the gear shaft 644a at the same speed Va. Then, the pinion gear 644 rotates interlockingly.

  On the other hand, as shown in the operation diagram of the AA ′ cross section illustrated as an example when the overload is limited in FIG. 12C, the drive roller 64 in the speed adjustment device 6 of the fourth embodiment has the roller shaft 641 having a predetermined restriction. When rotating at a speed Va exceeding a set speed (speed threshold Vth) for generating power, that is, when excessive speed rotation occurs, one end 643c of the shaft holding portion 643 (clutch spring) is formed on the protrusion 641b of the roller shaft 641. Is disengaged (or the projection 644c of the gear shaft 644a is engaged with the other end 643d of the shaft holding portion 643 (clutch spring)), and the rotation of the roller shaft 641 is caused by the rotation of the gear shaft. 644a is not transmitted at the same speed. For this reason, when the roller shaft 641 rotates at the rotational speed Va exceeding the speed threshold Vth, the gear shaft 644a is always restrained to the rotational speed Vb below the speed threshold Vth. The rotation of the pinion gear 644 serving as the shaft core is suppressed.

  Accordingly, the structure in which the roller shaft 641 and the gear shaft 644a are held by the shaft holding portion 643 configured by the clutch spring rotates the roller shaft 641 with reference to a set speed (speed threshold value Vth) that generates a predetermined braking force. Functions as an overload limiting mechanism that suppresses interlocking rotation with respect to the gear shaft 644a serving as the brake shaft of the brake portion 6a.

  In the example shown in FIG. 12, one end 643c of the shaft holding portion 643 (clutch spring) can be engaged with the protrusion 641b of the roller shaft 641, and the shaft holding portion 643 (clutch spring) is engaged with the protrusion 644c of the gear shaft 644a. The example of the shaft holding portion 643 (clutch spring) that enables the other end 643d of the shaft to be engaged has been described. However, only one of the one end 643c and the other end 643d of the shaft holding portion 643 (clutch spring) can be engaged. And the other may be fixed.

  Accordingly, in the horizontal blind according to the embodiment illustrated in FIG. 9 described above, when an excessive external force is generated on the bottom rail 4, the roller shaft 641 of the drive roller 64 in the speed adjusting device 6 according to the fourth embodiment is predetermined. The gear shaft 644a is always restrained to a rotational speed Vb that is equal to or lower than the speed threshold Vth even if it rotates at a speed Va that exceeds a set speed (speed threshold Vth) that generates a braking force of Thus, the rotation of the pinion gear 644 centering on the gear shaft 644a is suppressed, and it is possible to prevent breakage of each member or wear of the cord (in this example, the lifting / lowering cords C1, C2, C3) and the brake portion 6a. it can.

  In the first to fourth embodiments described above, generally, the shaft related to the roller portion 642 is configured by two shafts (the roller shaft 641 and the gear shaft 644a), and the roller shaft 641 and the gear shaft 644a are shafts that can be transmitted and separated. When an overload is detected by the holding shaft holding portion 643, the roller shaft 641 and the gear shaft 644a are separated so as not to rotate synchronously. Thereby, the roller shaft 641 of the roller unit 642 and the gear shaft 644a that applies the braking force can be reliably separated, and the performance related to the overload limitation by the shaft holding unit 643 can be enhanced.

  On the other hand, when an overload is detected by the shaft holding portion 643 that configures the shaft related to the roller portion 642 as one shaft (only the roller shaft 641) and holds the roller portion 642 and the roller shaft 641 so as to be able to transmit and separate, the roller portion It can be set as the structure which carries out rotation separation so that 642 and the roller shaft 641 may not rotate synchronously. In this case, the roller unit 642 can be supported by the roller shaft 641 serving as a single shaft, and the stability related to the overload limitation by the shaft holding unit 643 can be enhanced.

  As a typical example, the schematic configuration of the drive roller 64 including the overload limiting mechanism in the speed adjusting device 6 of the fifth, sixth, and seventh embodiments will be described below in order.

[Speed Adjustment Device of Example 5]
FIG. 13A is a diagram showing a schematic configuration of a drive roller 64 having an overload limiting mechanism in the speed adjusting device 6 of the fifth embodiment according to the present invention, and FIGS. 13B and 13C are AA views thereof. It is a figure which shows the general | schematic operation | movement at the time of a normal operation | movement at the time of a cross section, and an overload limit, respectively. In addition, the same reference number is attached | subjected to the component similar to Example 1. FIG.

  The speed adjustment device 6 of the fifth embodiment is configured as a modification of the first embodiment, and is substantially the same as the speed adjustment device 6 of the first embodiment shown in FIGS. 2 and 3 except that the structure of the drive roller 64 is different. Can be configured. For this reason, with reference to FIG. 13, the drive roller 64 which concerns on the speed adjustment apparatus 6 of Example 5 is demonstrated.

  In the speed adjusting device 6 of the fifth embodiment, as in the first embodiment, in addition to the braking torque amplification function, the braking torque adjustment function, and the cord movement detection function described above, unlike the conventional technique, A mechanism for realizing an overload limiting function as shown in 13 (a) is provided.

(Overload limit function)
More specifically, as shown in FIG. 13A, the drive roller 64 in the speed adjusting device 6 of the fifth embodiment includes a roller portion 642 that can transmit and separate with respect to the roller shaft 641 and a roller shaft 641. When the rotation speed of the roller part 642 exceeds the speed threshold Vth inside the roller part 642, the roller part 642 and the roller shaft are allowed to be elastically deformed. A shaft holding portion 643 that releases the interlocking rotation 641.

  In the present embodiment, the roller shaft 641 below the pinion gear 644 is pivotally supported by a corresponding groove of the C-shaped groove 692 provided in the raised portion 691 that rises in a circular shape at the approximate center of the base 69 shown in FIG. .

  In the roller shaft 641 of this embodiment, a square shaft 641c is formed in a region located inside the roller portion 642. On the other hand, a shaft holding portion 643 in which a square hole 643a that engages with the square shaft 641c is formed is fixedly accommodated on the inner peripheral surface of the roller portion 642.

  The shaft holding portion 643 of the present embodiment is configured by a buffer member such as a rubber material that allows elastic deformation when the rotation speed of the roller portion 642 exceeds the speed threshold value Vth.

  Therefore, the drive roller 64 in the fifth embodiment is configured as a modification of the second and third embodiments shown in FIG. 10 and FIG. 11, and is illustrated as a normal time (non-overload limit time) in FIG. -As shown in the operation diagram of the A 'cross section, if the rotation of the roller portion 642 is a rotation speed Va within a set speed (speed threshold Vth) for generating a predetermined braking force, the square shaft 641c of the roller shaft 641 is By maintaining the surface engagement with the square hole 643a of the shaft holding portion 643, the rotation of the roller portion 642 is transmitted to the roller shaft 641 at the same speed Va, and the pinion gear 644 rotates in conjunction with the rotation.

  On the other hand, as shown in the operation diagram of the AA ′ cross section illustrated as an example when the overload is limited in FIG. 13C, the drive roller 64 in the speed adjustment device 6 of the fifth embodiment has the roller portion 642 having a predetermined restriction. When rotating at a speed Va exceeding a set speed (speed threshold Vth) for generating power, that is, when excessive speed rotation occurs, the square hole 643a of the shaft holding portion 643 is elastically deformed, and the square shaft of the roller shaft 641 641c is in a state where the surface engagement with the square hole 643a of the shaft holding portion 643 is impaired, and the rotation of the roller portion 642 is not transmitted to the roller shaft 641 at the same speed. For this reason, when the roller unit 642 is rotating at the rotation speed Va exceeding the speed threshold Vth, the roller shaft 641 is always suppressed to the rotation speed Vb equal to or less than the speed threshold Vth. The rotation of the pinion gear 644 serving as the shaft core is suppressed.

  Therefore, the structure in which the roller holding portion 643 and the roller shaft 641 are held by the shaft holding portion 643 constituted by the buffer member is based on the set speed (speed threshold Vth) that generates a predetermined braking force. It functions as an overload limiting mechanism that suppresses the rotation of the roller shaft 641 that is the brake shaft of the brake unit 6a.

  In the example shown in FIG. 13, a shaft holding portion 643 configured by a buffer member such as a rubber material and having a square hole 643 a is fixed to the roller portion 642, and the roller shaft 641 performs surface engagement with the square hole 643 a. Although the example having the square shaft 641c that can be described has been described, as the reverse structure, the shaft holding portion 643 is fixed to the roller shaft 641, and the inner surface of the roller portion 642 is surface-engaged with the periphery of the shaft holding portion 643 or It is good also as a structure which enables transmission separation by friction.

  Accordingly, in the horizontal blind according to the embodiment illustrated in FIG. 9 described above, when an excessive external force is generated on the bottom rail 4, the roller portion 642 of the drive roller 64 in the speed adjusting device 6 according to the fifth embodiment is predetermined. Rotation at a speed Va exceeding the set speed (speed threshold value Vth) for generating the braking force, that is, even if an excessive speed rotation occurs, the rotation of the pinion gear 644 is always suppressed to the rotation speed Vb below the speed threshold value Vth. In addition, it is possible to prevent breakage of each member, or wear of the cords (the lifting cords C1, C2, C3 in this example) and the brake portion 6a.

[Speed adjusting device of Examples 6 and 7]
FIGS. 14A and 14B are diagrams showing a schematic configuration of a drive roller 64 provided with an overload limiting mechanism in the speed adjusting device 6 of Examples 6 and 7 according to the present invention, respectively. In addition, the same reference number is attached | subjected to the component similar to Example 1. FIG.

  The speed adjusting device 6 of the sixth and seventh embodiments can be configured in substantially the same manner as the speed adjusting device 6 of the first embodiment shown in FIGS. 2 and 3 except that the structure of the drive roller 64 is different. For this reason, with reference to FIG. 14 (a), (b), the drive roller 64 which concerns on the speed adjustment apparatus 6 of Example 6, 7 is demonstrated.

  In the speed adjusting device 6 of the sixth and seventh embodiments, like the first embodiment, in addition to the above-described braking torque amplification function, braking torque adjustment function, and cord movement detection function, the drive roller differs from the conventional technique. 64 is provided with a mechanism for realizing an overload limiting function as shown in FIGS.

(Overload limit function)
More specifically, first, as shown in FIG. 14A, the drive roller 64 in the speed adjusting device 6 of the sixth embodiment includes a roller portion 642 that can transmit and separate with respect to the roller shaft 641, and a roller shaft 641. A pinion gear 644 that rotates integrally with the roller shaft 641 as a core, and is disposed between the roller portion 642 and the pinion gear 644, and engages one end 643c with a protrusion portion 642a that protrudes downward on the circumferential surface of the roller portion 642. The shaft holding portion 643 is configured by a clutch spring by a compression spring that can engage the other end 643d with the protrusion 641d that partially protrudes on the circumferential surface of the roller shaft 641, and the rotation of the roller portion 642 When the speed exceeds the speed threshold Vth, the disengagement of one end 643c or the other end 643d of the clutch spring occurs. It includes a shaft holder 643 to release the interlocking rotation of the roller 642 and the roller shaft 641, a.

  Further, as shown in FIG. 14B, the drive roller 64 in the speed adjusting device 6 of the seventh embodiment includes a roller portion 642 that can transmit and separate with respect to the roller shaft 641, and a roller shaft 641 with the roller shaft 641 as an axis. One end 643c can be engaged with a pinion gear 644 that rotates integrally with the projection portion 642a that is disposed in the hollow portion 642b of the roller portion 642 and partially protrudes on the peripheral surface of the hollow portion 642b, and the roller shaft 641 The shaft holding portion 643 is constituted by a clutch spring that is a compression spring that can engage the other end 643d with the protruding portion 641d that partially protrudes outward on the peripheral surface of the roller, and the rotational speed of the roller portion 642 is a speed threshold value. When Vth is exceeded, the disengagement of the one end 643c or the other end 643d of the clutch spring occurs, and the roller portion 642 It includes a shaft holder 643 to release the interlocking rotation of Ra shaft 641, a.

  That is, the difference between the sixth embodiment and the seventh embodiment is that the shaft holding portion 643 constituted by the clutch spring is disposed between the roller portion 642 and the pinion gear 644 (see FIG. 14A). It is only the point whether it is arrange | positioned in the cavity part 642b inside the roller part 642 (refer FIG.14 (b)), and a substantial structure is the same.

  In Examples 6 and 7, the roller shaft 641 below the pinion gear 644 is formed in a groove corresponding to the C-shaped groove 692 provided in the raised portion 691 that rises in a circular shape at the approximate center of the base 69 shown in FIG. It is pivotally supported.

  Accordingly, the drive roller 64 in the sixth and seventh embodiments shown in FIGS. 14A and 14B is configured as a modification of the fourth embodiment shown in FIG. 14, and the rotation of the roller portion 642 is predetermined. If the rotation speed Va is within a set speed (speed threshold Vth) that generates the braking force of the roller, a state in which one end 643c of the shaft holding portion 643 (clutch spring) is engaged with the protrusion 642a of the roller portion 642, and the roller shaft By maintaining the state in which the other end 643d of the shaft holding portion 643 (clutch spring) is engaged with the protruding portion 641d of 641, the rotation of the roller portion 642 is transmitted to the roller shaft 641 at the same speed Va and the pinion gear 644 is interlocked. Rotate.

  On the other hand, in the drive rollers 64 in Examples 6 and 7, when the roller portion 642 rotates at a speed Va that exceeds a set speed (speed threshold Vth) that generates a predetermined braking force, that is, when an excessive speed rotation occurs. In addition, one end 643c of the shaft holding portion 643 (clutch spring) is engaged with the protrusion 642a of the roller portion 642 (or the other end 643d of the shaft holding portion 643 (clutch spring) is connected to the protrusion 641d of the roller shaft 641. In the engaged state), the rotation of the roller portion 642 is not transmitted to the roller shaft 641 at the same speed. For this reason, when the roller unit 642 is rotating at the rotation speed Va exceeding the speed threshold Vth, the roller shaft 641 is always suppressed to the rotation speed Vb equal to or less than the speed threshold Vth. The rotation of the pinion gear 644 serving as the shaft core is suppressed.

  Accordingly, the structure in which the roller portion 642 and the roller shaft 641 are held by the shaft holding portion 643 configured by the clutch spring rotates the roller portion 642 with reference to a set speed (speed threshold value Vth) that generates a predetermined braking force. Functions as an overload limiting mechanism that suppresses interlocking rotation with respect to the roller shaft 641 serving as the brake shaft of the brake portion 6a.

  In the example shown in FIGS. 14A and 14B, one end 643c of the shaft holding portion 643 (clutch spring) can be engaged with the protrusion 642a of the roller portion 642, and the protrusion 641d of the roller shaft 641 can be engaged. The example of the shaft holding portion 643 (clutch spring) that can engage the other end 643d of the shaft holding portion 643 (clutch spring) has been described, but either the one end 643c or the other end 643d of the shaft holding portion 643 (clutch spring) is described. Only one of them may be engaged, and the other may be fixed.

  Accordingly, in the horizontal blind according to the embodiment illustrated in FIG. 9 described above, when an excessive external force is generated on the bottom rail 4, the roller portion 642 of the drive roller 64 in the speed adjusting device 6 according to the sixth and seventh embodiments. Rotates at a speed Va exceeding a set speed (speed threshold Vth) for generating a predetermined braking force, that is, even if an excessive speed rotation occurs, the rotation of the pinion gear 644 always becomes the rotation speed Vb equal to or less than the speed threshold Vth. It is suppressed and it is possible to prevent breakage of each member or wear of the cords (in this example, the lifting / lowering cords C1, C2, C3) and the brake portion 6a.

  As a modification of the drive roller 64 having the serration structure of the first embodiment, the shaft relating to the roller portion 642 is 1 by adopting a structure in which serration engagement is performed between the roller portion 642 and the roller shaft 641. When an overload is detected by the shaft holding portion 643 configured with two shafts (only the roller shaft 641) and holding the roller portion 642 and the roller shaft 641 so that transmission and separation are possible, the roller portion 642 and the roller shaft 641 do not rotate synchronously. It can be set as the structure which carries out rotation separation.

  In each of the above embodiments, an overload limiting mechanism based on serration engagement of each shaft supported by the shaft holding portion 643 of the first embodiment and the shaft holding portion 643 of the second, third, and fifth embodiments are roughly classified. The overload limiting mechanism based on the buffer member and the overload limiting mechanism based on the clutch spring constituting the shaft holding portion 643 of the fourth, sixth, and seventh embodiments have been described. A load limiting mechanism may be provided.

  However, in the case of an overload limiting mechanism based on serration engagement, it is possible to apply braking torque and limit overload only by setting the number of teeth and the number of teeth related to serration engagement without increasing the speed adjustment device 6. Easy to adjust. Further, the speed adjustment device 6 can be configured without impairing the above-described braking torque amplification function, braking torque adjustment function, and cord movement detection function.

  Further, if the overload limiting mechanism is based on the buffer member, it is possible to avoid the complicated structure without increasing the speed adjustment device 6 and to use an inexpensive rubber material or the like as the buffer member. Realized by the number of parts). The speed adjusting device 6 can be configured without impairing the above-described braking torque amplification function, braking torque adjustment function, and cord movement detection function.

  In addition, if the overload limiting mechanism is based on a clutch spring, the braking torque can be easily applied and the overload limiting threshold can be set only by adjusting the urging force without increasing the size of the speed adjusting device 6. . The speed adjusting device 6 can be configured without impairing the above-described braking torque amplification function, braking torque adjustment function, and cord movement detection function.

  The present invention has been described above with reference to specific embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the technical concept thereof. For example, in the example of the above-described embodiment, an example of a horizontal blind that uses a lifting / lowering cord that moves as a cord related to a pulling operation as a speed conversion target has been described, but by moving a cord for moving a shielding material, Horizontal blinds, pleated screens, roman shades, vertical blind accordion curtains, roll screens, etc. that can open and close shielding materials with mechanical automatic operation that adjusts the speed in one direction among the opening and closing directions and manual operation in the other direction If it is a shielding apparatus, the speed adjustment apparatus 6 which concerns on this invention is applicable.

  In the example of the embodiment described above, the configuration example in which the braking torque is generated by the centrifugal brake in the speed adjusting device 6 has been described. However, the braking torque may be generated by an oil type or pneumatic type damper.

  According to the present invention, even when the shaft of the drive roller connected to the brake unit rotates at a speed exceeding the set speed for generating the braking force, it is possible to prevent failure of the members related to the speed adjusting device, to prevent cord wear, etc. Since the quality can be maintained, it is useful for the use of a shielding device with speed adjustment.

1 Headbox C1, C2, C3 Lift code (traction code)
3 Shielding material (slats)
4 Bottom rail 5 Support member 6 Speed adjusting device 6a Brake part 7 Operation code 8 Code equalizer 60 Alignment member 61 Case 62 Slider SP Coil spring 63 Idle roller 64 Drive roller 65 Internal toothed carrier 66 Annular plate 67 Weight holder with sun gear Weight 69 Base 641 Roller shaft 642 Roller portion 643 Shaft holding portion 644 Pinion gear 644a Gear shaft 645 Support shaft 645b Compression spring

Claims (10)

A speed adjusting device capable of adjusting a moving speed of a cord related to opening and closing of a shielding material,
Brake means for applying a braking force to the movement of the cord;
Overload limiting means for limiting overload of the brake means when the moving speed of the cord exceeds a predetermined set speed;
A speed adjusting device comprising: A rotating body that rotates according to the movement of the cord;
The speed adjusting device according to claim 1, wherein the brake means is configured to apply a braking force to the movement of the cord by applying a braking torque to the shaft of the rotating body. .   The overload limiting means transmits the rotation at the same speed as the rotation of the rotating body to the brake means when the rotation of the rotating body is within a predetermined speed threshold, and the rotation of the rotating body is the predetermined rotation. 3. The overload of the brake unit is limited by transmitting to the brake unit a rotation at a lower speed than the rotation speed of the rotating body when the rotation speed exceeds a speed threshold value. Speed adjuster.   The said overload limiting means has a shaft holding part which engages and hold | maintains the axis | shaft of the said rotary body, and the axis | shaft which provides a braking torque with the said brake means so that transmission isolation | separation is possible. Or the speed adjustment apparatus of 3.   The overload limiting means includes a shaft holding portion that holds the rotating body and a shaft of the rotating body to which braking torque is applied by the brake means so as to be able to be transmitted and separated. Item 4. The speed adjusting device according to Item 2 or 3.   6. The speed adjusting device according to claim 4, wherein the overload limiting unit includes the serration engagement of the shaft holding unit to limit the overload of the brake unit.   6. The speed adjusting device according to claim 4, wherein the overload limiting means is configured by an elastically deformable damping member that restricts the overload of the brake means.   The speed adjusting device according to claim 4 or 5, wherein the overload limiting means includes the shaft holding portion configured by a clutch spring to limit an overload of the brake means.   A second rotating body sandwiching the cord opposite to the rotating body, wherein a distance between the rotating body and the second rotating body is close or separated depending on a moving direction of the cord; The speed adjusting device according to any one of claims 2 to 8, wherein the speed adjusting device is configured to detect the presence / absence and movement direction of the cord.   The brake means is configured to apply a braking torque to the shaft of the rotating body by a centrifugal brake or a predetermined damper, a means for amplifying the braking torque based on the rotation of the rotating body, and the braking torque in multiple stages. The speed adjusting device according to any one of claims 2 to 9, further comprising: means for making adjustment possible.