The present invention is related to an operation cord suitably used in a horizontal blind, a vertical blind, a shade, a screen window, an up-down sliding window, an awning, a skylight window, a laundry pole and the like, and to an elevation apparatus employing the same.
A kind of a horizontal blind is known where an endless-type operation cord is engaged with a pulley that is supported so as to be rotatable at an end of a head box, and the operation cord is operated to rotate the pulley so that operations for moving slats up and down and adjusting their angle are enabled. Further, a technique is known in which an operation cord is wound around a pulley to operate a vertical blind (see Patent Document 1).
Such an operation cord is formed to be endless through fusing or stitching together both ends of a cord which is formed of a synthetic resin into a string shape. The operation cord of this type is engaged with a concavity formed on a peripheral surface of the pulley without touching the inside of a pulley case in which the pulley is disposed so that the operation cord can rotate the pulley.
When the endless-type operation cord mentioned above is hanging down from the pulley, part of the endless operation cord sometimes catches a dweller moving in the room or another moving object. Especially, if the operation cord catches a child or an aged person, a dangerous situation easily occurs in which the operation cord tangles around the neck, or the child or the aged person falls down. As a countermeasure against this problem, the following operation cord is proposed. That is, an operation cord which is used in an arrangement where a supporting frame for suspending a light shielding member such as a shade, a blind or a curtain is disposed on a wall surface around a window, to open and close the suspending light shielding member horizontally or vertically, and hanging down from the supporting frame, is provided with a safety member which can be attached and detached and is configured to be deconstructed when a fast and furious force is applied in an extending direction of the operation cord (see Patent Document 2).
However, with the operation cord disclosed in Patent Document 2 or 3, while a failsafe function can be achieved to a certain degree, there remains the following problem. That is, in such an operation cord, the safety member tends to be thicker than the operation cord, so that inconvenience is caused in using it. For example, in case of a horizontal blind in which the operation cord is rotated one turn or more around the pulley to perform an operation for moving the slats up and down, the safety member sometimes touches the inside of the pulley case or gets hung up in a concavity formed on the peripheral surface of the pulley. As a result, the operation for moving the slats up and down or for adjusting their angle is hindered. Further, it is highly probable that the pulley and the like are damaged.
Accordingly, the present invention is made to solve the above-mentioned problem, and the object thereof is to enable smooth rotation of an operation cord and to provide an operation cord equipped with a failsafe function and an elevation apparatus employing the operation cord.
To achieve the object, an operation cord according to claim 1 is suggested.
In the operation cord of the above-mentioned configuration, the coupling portion cannot be a hindrance during rotation, so that the operation cord is rotated smoothly. Further, through adjustment of a coupling force of the coupling portion, the operation cord can be divided at the coupling portion when a fast and furious force is applied in an extending direction of the operation cord, so that the operation cord is equipped with a failsafe function.
According to a further embodiment, in the above-mentioned invention, each end of the cord is so formed that a diameter thereof gets smaller as a distance to the coupling portion decreases.
In the operation cord of the above configuration, each end of the cord can be surely connected to the coupling portion, and it is easy to make the outer diameter of the coupling portion in the lateral direction equal to or smaller than the maximum diameter of the cord.
According to a further embodiment, in the above-mentioned invention, a length of the coupling portion in a longitudinal direction is at least 1.2 times the maximum diameter of the cord and at most 2.5 times the maximum diameter of the cord.
In the operation cord of the above configuration, the coupling portion is prevented from touching the inside of the pulley case so that the pulley can be rotated smoothly.
According to a further embodiment, in the above-mentioned invention, the coupling portion comprises a first joint body provided at one end of the cord, a second joint body provided at another end of the cord, and a joint ring provided between the first joint body and the second joint body, wherein the first joint body and the second joint body each have a fitting protrusion of an axial shape, the joint ring has fitting holes each configured to fit with the fitting protrusion, the fitting protrusion is configured to engage with the fitting hole through being inserted in the fitting hole and subsequently rotated, and the first joint body, the second joint body and the joint ring are each so configured that an outer diameter thereof in a lateral direction is equal to or smaller than the maximum diameter of the cord.
In the operation cord of the above configuration, the operation cord can be rotated smoothly, and an operation cord equipped with a failsafe function is realized. That is, the coupling portion of the operation cord, which is formed to have an outer diameter in the lateral direction equal to or smaller than the maximum diameter of the cord, seldom touches the inside of the pulley case or the like. Further, the coupling portion is prevented from getting hung up in a concavity or the like formed on a peripheral surface of the pulley. Moreover, the coupling portion is provided with the first joint body, the second joint body and the joint ring disposed between the first joint body and the second joint body, and each of the fitting protrusions provided in the first joint body and the second joint body can engage with the fitting hole provided in the joint ring through being inserted in the fitting hole and subsequently rotated, so that it is possible to make fitting of the fitting protrusion of the coupling portion with the fitting hole break easily, when a great pull force exceeding a normal pull force is applied to the operation cord. Accordingly, when part of the endless operation cord catches a dweller moving in the room or another moving object, it is easy to cut the operation cord at the coupling portion to ensure safety, and to obviate damaging the pulley or the like with which the operation cord is engaged.
According to a further embodiment, in the above-mentioned invention, a fitting position of the fitting protrusion and the fitting hole is set at a position to which the fitting protrusion is brought through a rotation by 90 degrees after inserted in the fitting hole.
In the operation cord of the above configuration, it is possible to ensure a sufficient holding force to hold the fitting protrusion in the fitting hole, while minimizing an operation force to make the fitting protrusion fit in the fitting hole.
According to a further embodiment, in the above-mentioned invention, the first joint body and the second joint body are each formed at one end or another end of the cord by means of outsert molding.
In the operation cord of the above configuration, joint force of each of the first joint body and the second joint body with the cord can be enhanced.
According to a further embodiment, in the above-mentioned invention, the cord is made of a thermoplastic resin, and a tip of each end of the cord is provided with a flange configured to fit with the first joint body or the second joint body.
In the operation cord of the above configuration, it is possible to ensure sufficient joint force of each of the first joint body and the second joint body with the cord by way of each flange.
According to a further embodiment, in the above-mentioned invention, the first joint body, the second joint body and the joint ring are molded from a synthetic resin, the fitting protrusion is provided with swelled portions each having a diameter greater than a diameter of a base end of the fitting protrusion, and the fitting hole is provided with a first locking portion and a second locking portion each configured to engage with the swelled portion.
In the operation cord of the above configuration, the swelled portions of the fitting protrusion can be fit and held resiliently in the first locking portion and the second locking portion. As a result, it is possible to ensure a sufficient holding force to hold the fitting protrusion in the fitting hole.
According to a further embodiment, in the above-mentioned invention, the first locking portion and the second locking portion are provided mirror symmetrically within openings of the fitting holes so as to be rotationally shifted from each other by 90 degrees.
In the operation cord of the above configuration, the first joint body and the second joint body each fitted in the joint ring are held in a state where their fitting protrusions are rotationally shifted from each other by 90 degrees. Therefore, when a pull force is applied to each of the fitting protrusions, the swelled portions of the both fitting protrusions work, by way of the first locking portion and the second locking portion, on the openings of the joint ring so as to push out them in directions shifted from each other by 90 degrees. Therefore, it is easy to ensure a sufficient holding force.
According to a further embodiment, in the above-mentioned invention, the swelled portion and an inner peripheral surface of the fitting hole are provided with positioning means for determining a rotational position of the fitting protrusion.
In the operation cord of the above configuration, through determining the rotational position of the fitting protrusion, it is possible to ensure a sufficient holding force to hold the fitting protrusion in the fitting hole.
According to a further embodiment, an elevation apparatus comprises the operation cord of any one of claims 1 to 9.
In the elevation apparatus of the above configuration, the operation cord can be rotated smoothly and, at the same time, a failsafe function is equipped.
According to the present invention, smooth rotation of the operation cord is enabled, and an operation cord equipped with a failsafe function and an elevation apparatus employing the operation cord are provided.
Hereafter, preferred embodiments of an operation cord according to the present invention and an elevation apparatus employing the operation cord will be described in detail with reference to the drawings. However, the present invention is not limited to any of the following preferred embodiments by any means.
In the horizontal blind shown in
Hoisting cords 5 are inserted in the slats 3 at positions near supporting positions of the ladder cords 2. The bottom rail 4 is supported by bottom ends of the hoisting cords 5 so as to suspend therefrom. Top ends of the hoisting cords 5 are wound around a winding shaft 7 which is supported so as to be rotatable by a supporting member disposed in the head box 1.
As shown in
When the pulley 16 is rotated, a tilt drum 13 is rotated via gears in the gear box 10, a tilt shaft 12b and the like, so that the respective slats 3 are turned via the ladder cords 2.
As shown in
As shown in
Further, a tip of each tapered end of the cord 14, which is made of a thermoplastic resin, is provided with a flange 30 configured to fit with the first joint body 40 or the second joint body 41. In this embodiment, as shown in
Various methods can be employed in attaching the first joint body 40 or the second joint body 41 to the tip of each end of the cord 14. For example, firstly, the tip of each end of the cord 14 is heated while being compressed, and the ring-shaped flange 30 is formed using a mold prepared beforehand. Subsequently, the first joint body 40 or the second joint body 41 is formed by means of outsert molding so as to cover the flange 30. Through such outsert molding, each end of the cord 14 is fixed to the first joint body 40 or the second joint body 41 with enhanced joint force. Note, however, that the method of integrating the first joint body 40 or the second joint body 41 with the cord 14 is not limited to the method described above. For example, the first joint body 40 or the second joint body 41 is formed first, and thereafter the flange 30 formed at each end of the cord 14 is fitted in the first joint body 40 or the second joint body 41.
Further, as shown in
As shown in
On an outer peripheral surface of a tip of the fitting protrusion 45, two swelled portions 46 are formed line symmetrically with regard to a center of the round shank so as to have a greater outer diameter. At a middle in a radial direction of each of the swelled portions 46 is formed a locking concavity 47 which is a concavity having a semicircular cross section. Further, chamfered edges 54 are formed on a front end side and a base end side of the swelled portion 46. A cross section of the swelled portion 46, cut along a central axis, has a trapezoidal shape due to the chamfered edges 54, 54.
At a base end of the fitting protrusion 45, that is, on the side to the flange 30, as shown in
The joint ring 42 is formed entirely into a cylindrical shape. As shown in
Within the joint ring 42, a circular hole (fitting hole) 50 is formed having a diameter which allows the tip of the fitting protrusion 45 to rotate. The circular hole 50 has a center which is identical with a center of the outer diameter of the joint ring 42. Further, at each of opening edges, in a shorter-axis direction, of the laterally long opening 49a shown in
As shown in
Further, a locking protrusion 53a protruding inward in a radial direction is formed on the inside of the first locking portion 51a, and a locking protrusion 53b protruding inward in a radial direction is formed on the inside of the second locking portion 51c. That is, a locking protrusion 53a, 53b configured to engage with the locking concavity 47 is formed on an inner peripheral surface of each of the circular holes 50. To couple the first joint body 40 and the joint ring 42, the fitting protrusion 45 of the first joint body 40 is inserted in the opening 49b of the joint ring 42, and then the first joint body 40 is rotated by 90 degrees with respect to the joint ring 42 in a counter clockwise direction, as seen from the opening 49a. As a result, the locking concavity 47 of the fitting protrusion 45 engages with the locking protrusion 53a in the circular hole 50, one of the rotation restriction portions 48 moves from a side of one second locking portion 51c to a side of another second locking portion 51d so as to abut the second locking portion 51d, and the other of the rotation restriction portions 48 moves from the side of the other second locking portion 51d to the side of the one second locking portion 51c so as to abut the second locking portion 51c, and thus, they are positioned as shown in
Also, the second joint body 41 is similarly inserted in the other opening 49a of the joint ring 42 and then relatively rotated by 90 degrees, so that they are positioned. As a result, as shown in
In this state, the swelled portions 46 of each of the fitting protrusions 45 of the first joint body 40 and the second joint body 41 engage with each of the locking portions 51a to 51d of the joint ring 42, and are held within the circular holes 50 of the joint ring 42.
A force for this holding is so set that the fitting protrusion 45 never drops out of the joint ring 42 with a normal pull force applied to the operation cord 9 during a normal operation for moving the slats up and down and adjusting the angle of the slats. Moreover, only when a great force exceeding the normal pull force is applied to the operation cord 9, the openings 49a, 49b of the joint ring 42 are expanded in the radial directions by the swelled portions 46 of the fitting protrusions 45 due to resiliency of the synthetic resin of the joint ring 42, so that the fitting protrusion 45 drops out of the joint ring 42. In this process, either one of the first joint body 40 and the second joint body 41 first drops out of the joint ring 42. Therefore, a state arises where the joint ring 42 is engaged with one of the first joint body 40 and the second joint body 41, and thus, the joint ring 42 never drops off the operation cord 9.
The operation cord 9 configured as described above can be rotated unlimitedly and smoothly relative to the pulley 16 and is equipped with a failsafe function. After the fitting at the coupling portion 20 is broken, the first joint body 40 or the second joint body 41 can be fitted in the joint ring 42 again, so that the endless operation cord 9 is easily reconstructed. Further, since a configuration is adopted where the fitting protrusion 45 is inserted in the opening 49a, 49b of the joint ring 42 and subsequently rotated by 90 degrees to achieve the fitting of the fitting protrusion 45 with the joint ring 42, it is possible to minimize the operation force needed for fitting the fitting protrusion 45 with the joint ring 42.
Moreover, since the pulling force in the direction of the axis of the swelled portion 46 is sustained by each of the locking portions 51a to 51d, it is possible to make the holding force to hold the fitting protrusion 45 in the joint ring 42 sufficiently strong. Also, when the locking protrusion 53a, 53b is fitted in the locking concavity 47, the position can be certainly maintained since the positioning is realized by working of the rotation restriction portion 48.
The elevation apparatus employing the operation cord 9 according to one embodiment of the present invention can be suitably used for a light shielding apparatus such as, in addition to the horizontal blind shown in
A horizontal blind has been described thus far, as a preferable embodiment of the operation cord 9 and the elevation apparatus using the same according to the present invention, however, the present invention is not limited to the embodiment shown above, but can be implemented in variously altered forms.
Further, a step having a cross-section of a right angle may be provided in place of the chamfered edge 52 in the joint ring 42. Though two members are provided for each of the swelled portion 46, the locking concavity 47, the first locking portion 51a, 51b and the second locking portion 51c, 51d, one member of three or more members may be provided for each of them. In this case, a value other than 90 degrees is preferably employed for the rotation angle.
Moreover, the cord 14 may be formed of a resin other than a thermoplastic resin or of braided threads. Though each end of the cord 14 is formed into the reduced diameter portion 35 which is gradually reduced in diameter size, it may be formed into a small diameter portion 35 having a fixed diameter from a certain point to the tip. Further, the end may be formed by means of outsert molding without providing the flange 30.
Further, the arrangement or the number of the coupling portion 20, 60, for example, may be properly selected in accordance with the design and the failsafe function as needed. The connection of the cord 14 and the first joint body 40 or the integrated portion 61, or the connection of the cord 14 and the second joint body 41 may be established by a method other than outsert molding, for example, by bonding with an adhesive agent.
Though, in each of the embodiments described above, the outer diameters of the first joint body 40, the second joint body 41, and the joint ring 42 are all made equal to the outer diameter of the coupling portion 20 in the lateral direction, a configuration may be employed where only one or two of the two members or three members are made larger to have a diameter equal to the diameter M of the coupling portion 20, and remaining one or two members are made to have a smaller diameter. Furthermore, though these three or two members are molded from a synthetic resin, they may be made of another material, such as a metallic material.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.