JP7502013B2 - Ball Chain - Google Patents

Description

The present invention relates to a ball chain in which a first end and a second end of the chain are connected by a connecting part.

Ball chains are used as operating cords for the slats in horizontal blinds and for the screen lifting devices in roller screens. For example, Patent Document 1 describes a ball chain in which plastic balls are attached at equal intervals to a plastic string. The operating cord has a fail-safe function that cuts it when a pulling force that exceeds the pulling force during normal operation is applied.

Patent No. 5613387

In a resin ball chain, the string that connects the holes and the balls is made of the same resin, and the string is integrated with the balls. Therefore, with a ball chain, there is a risk that the string will come loose from the balls after repeated use.

The present invention was made to solve the above problems, and its purpose is to provide a ball chain that can prevent the link shafts that connect the balls from falling off.

The ball chain that solves the above problem is a ball chain in which multiple balls are connected by a link shaft, the link shaft having an axle portion and an integration portion for integrating the link shaft with a molded portion provided at the end of the axle portion, the integration portion including a convex or concave portion.

In the above ball chain, the anti-slip portion may be configured as an enlarged diameter portion.
In the above ball chain, the ball chain is formed by connecting a first end and a second end with a connecting portion, and when a tensile force exceeding the tensile force during normal operation is applied to the ball chain, the first connector constituting the first end and the second connector constituting the second end are separated from each other, and each connector has the link shaft and a mating portion constituted by the molded portion that is provided on the link shaft and connected to the mating portion of the other connector, the mating portion of the first connector is a first mating portion, the mating portion of the second connector is a second mating portion, and the first mating portion and the second mating portion may be connected via a connecting member.

The ball chain for solving the above problem is a ball chain in which multiple metal balls are connected by a metal link shaft, and the first and second ends of the ball chain are connected by a connecting part, and when a tensile force that exceeds the tensile force during normal operation acts on the ball chain, at least the first end or the second end of the connecting part comes off.

The present invention makes it possible to prevent the link shaft that connects the balls from falling off.

Front view of the roller blind. 1A is a side view of a key portion of a ball chain, FIG. 1B is an enlarged cross-sectional view of a key portion of the ball chain, and FIG. 1C is an enlarged side view of a key portion of a connecting portion. 1 is an exploded perspective view of a connecting portion that connects a first end and a second end of a ball chain in a first embodiment. FIG. FIG. 4 is a front view showing the relationship between a connector and a link shaft in the first embodiment. 3A, 3B, 3C, and 3D are diagrams showing a first connector and a second connector in the first embodiment, in which FIG. 1A is a plan view of a connecting member according to a first embodiment, FIG. 1B is a bottom view, FIG. 1C is a cross-sectional view taken along the line cc of FIG. 1A, and FIG. 1D is a cross-sectional view taken along the line dd of FIG. 4 is a cross-sectional view showing a state in which the first connector and the second connector are connected by a connecting member in the first embodiment. FIG. 13 is a cross-sectional view showing a state in which the first connector and the second connector are connected by a connecting member in the second embodiment. FIG. FIG. 11 is a side view of a link shaft according to the second embodiment. 13 is a cross-sectional view showing a state in which the first connector and the second connector in the third embodiment are connected by a connecting member. FIG. FIG. 13 is a side view of a link shaft according to a third embodiment. 13 is a cross-sectional view showing a state in which the first connector and the second connector in the fourth embodiment are connected by a connecting member. FIG. FIG. 13 is a side view showing a modified example of the link shaft. FIG. 13 is a side view showing a modified example of the link shaft.

Hereinafter, a roll screen using a ball chain to which the present invention is applied as an operating cord will be described with reference to the drawings.
First Embodiment
As shown in Fig. 1, as an example, the roller blind 10 is attached to a window frame and used as a shading device for blocking sunlight, etc., and is also used as a shading device for separating a first space and a second space, such as a room and a staircase, to block air flow, etc. Such a roller blind 10 is attached to an installation part provided on a window frame or a ceiling.

The roll screen 10 includes a head portion 11 that is attached to the installation portion, and a screen 12 that serves as a shielding material and hangs down from the head portion 11. The head portion 11 is attached to the installation portion via a bracket. The head portion 11 includes side covers 13 at both ends in the width direction. The side covers 13 rotatably support a winding pipe 14 that winds the screen 12 inside. The winding pipe 14 extends in the width direction of the head portion 11, and includes a pulley 15 at one end in the width direction that rotates the winding pipe 14. The pulley 15 is engaged with a ball chain 16, which is a circular operating chain that rotates the winding pipe 14, as an operating portion. The ball chain 16 hangs down from one end in the width direction of the head portion 11, and two chains that constitute the ball chain 16 hang down. The ball chain 16 rotates the winding pipe 14 in the direction in which the screen 12 is pulled out or in the direction in which the screen 12 is wound by performing an operation to pull down one of the two chains. This causes the screen 12 to rise and fall together with the weight bar 9.

The screen 12 is, for example, a flexible sheet. In the vertical direction, which is the direction in which the screen 12 is wound up and pulled out, one end of the screen 12 is fixed to the winding pipe 14, and the other end is attached to a weight bar 9 that stabilizes the position of the screen 12 in the vertical direction.

Next, a specific configuration of the ball chain 16 will be described.
As shown in Fig. 2(a), the ball chain 16 is an operating chain for pleated screens, and is a metal ball chain. The ball chain 16 includes a number of metal balls 16a and metal link shafts 16b that connect adjacent metal balls 16a. The metal balls 16a are formed into spheres by crimping metal plates such as stainless steel, and the two opposing apexes have through holes 16d formed by butting recesses together. The ball diameter of the metal balls 16a is, for example, about a few millimeters, preferably 4.5 mm.

As shown in FIG. 2(b), the metal link shaft 16b is a straight member with flanges 16c at each end. The metal link shaft 16b engages with the recess of the metal ball 16a in the expanded state and is then crimped to form a spherical shape. Furthermore, the flanges 16c are positioned inside the metal ball 16a, preventing the metal link shaft 16b from slipping out of the metal ball 16a. Adjacent metal balls 16a are connected by the metal link shaft 16b to form a single ball chain 16.

As shown in FIG. 2(c), both ends of a single ball chain 16 before it becomes a loop, i.e., a first end 17 and a second end 18, are connected by a connecting portion 21 to form an endless chain.
3, the connecting portion 21 includes a first connector 22a constituting the first end portion 17, a second connector 22b constituting the second end portion 18, and a connecting member 23 connecting the first connector 22a and the second connector 22b. Note that the first connector 22a and the second connector 22b have the same configuration, and therefore are collectively referred to as the connector 22.

As shown in FIG. 4, the connector 22 includes a link shaft 26 and a resin fitting portion 27 as a fitting portion. The link shaft 26 includes a metal shaft portion 26a having a straight shape, an integrated portion 26b provided at one end of the metal shaft portion 26a, and a retaining portion 26c provided at the other end of the metal shaft portion 26a. The integrated portion 26b is a convex portion that is integrated with the resin fitting portion 27 that is fitted with the connecting member 23, that is, functions as a retaining portion. The integrated portion 26b is an enlarged diameter portion that protrudes in the outer circumferential direction from the metal shaft portion 26a and has a flange shape that is continuous in the circumferential direction. A plurality of enlarged diameter portions are provided at one end of the metal shaft portion 26a, parallel to the axial direction and spaced apart. The number of enlarged diameter portions is not particularly limited, and may be three or more, or may be one. If the number of enlarged diameter portions is large, it is difficult for the link shaft 26 to come off from the resin fitting portion 27, and if the number of enlarged diameter portions is small, the shape of the link shaft 26 can be simplified and manufacturing is easy. The enlarged diameter portion may also have a notch in the radial direction and be discontinuous in the circumferential direction.

The retaining portion 26c is a protrusion for preventing the metal ball 16a from falling out, and is a metal expanded diameter portion. The metal shaft portion 26a is inserted into the through hole 16d, and the retaining portion 26c is positioned inside the metal ball 16a. The surface of the retaining portion 26c facing the metal shaft portion 26a has an inclined or spherical shape that corresponds to the inner surface of the metal ball 16a. The shape of the surface on the opposite side of the retaining portion 26c is not particularly limited, but is configured as a flat surface here.

As shown in Fig. 5(a) to Fig. 5(d), the resin fitting portion 27 is a resin molded portion made of a synthetic resin material such as polyester, polypropylene, or polyacetal, and has a spherical trapezoid shape. Specifically, the resin fitting portion 27 has a spherical notch portion 28 having a spherical notch shape cut by a single plane of a sphere, and a fitting protrusion 29 formed on the flat bottom surface portion of the spherical notch portion 28. The surface of the resin fitting portion 27, and particularly the spherical notch portion 28, constitutes the appearance of the ball chain 16 together with the metal ball 16a, so it can be painted or plated so that it has the same appearance as the metal ball 16a. The fitting protrusion of the first connector 22a is also called the first fitting protrusion 29a, and the fitting protrusion of the second connector 22b is also called the second fitting protrusion 29b.

The spherical notch 28 has a shape cut out at a position about 1/4 of the way around the sphere, with the metal shaft portion 26a extending from the apex of the sphere. The link shaft 26 is integrated with the resin fitting portion 27 in a non-slip state by insert molding one end of the link shaft 26 with the integrated portion 26b into the resin fitting portion 27. This results in the metal shaft portion 26a and the non-slip portion 26c extending from the apex of the sphere of the spherical notch 28. The spherical notch 28 has a straight portion 30 at a position opposite to the cut-out at the outer periphery. This makes it easier to grasp the position of the straight portion 30 of the connector 22 with a jig during assembly or repair.

The fitting protrusion 29 is a protrusion that protrudes from the top of the ball recess 28 on the opposite side to the link shaft 26. The outer peripheral surface of the tip of the fitting protrusion 29 is provided with a bulged diameter portion 31 that is linearly symmetrical with respect to the center of the round shaft. The middle of the bulged diameter portion 31 is provided with a recess 32 that is semicircular in cross section. The bulged diameter portion 31 on the first connector 22a side is also called the first bulged diameter portion 31a, and the bulged diameter portion 31 on the second connector 22b side is also called the second bulged diameter portion 31b. The ball recess 28 and the bulged diameter portion 31 are spaced apart in the axial direction of the metal shaft portion 26a. A rib 33 is provided between the ball recess 28 and the bulged diameter portion 31 for reinforcement and the like. The rib 33 engages with a protrusion 37 provided on the inner peripheral surface of the connecting member 23 to prevent rotation.

As shown in Figs. 6(a) to 6(d), the connecting member 23 has a spherical trapezoid shape sandwiched between two parallel planes. The connecting member 23 is a resin molded body made of synthetic resin material such as polyester, polypropylene, polyacetal, etc., and is a resin member. The connecting member 23 has a through hole in the height direction, and as shown in Fig. 6(a), the through hole forms a first mating recess 34a on the first plane facing the first connector 22a, and as shown in Fig. 6(b), the through hole forms a second mating recess 34b on the second plane facing the second connector 22b. The first mating recess 34a and the second mating recess 34b are collectively referred to as the mating recess 34.

The first fitting recess 34a and the second fitting recess 34b are formed in a bale shape into which the tip of the fitting protrusion 29, including the expanded diameter portion 31, can be inserted. In addition, the first fitting recess 34a and the second fitting recess 34b are shaped such that the direction of the bale shape is rotated 90 degrees from each other with respect to the center of the cylinder.

6(c) and 6(d), the through hole in the connecting member 23 is configured with a circular hole 35 having a diameter that allows the tip of the fitting protrusion 29 to rotate. A first locking portion 36a that prevents the first bulging portion 31a from slipping out of the circular hole 35 is formed on the opening edge of the first fitting recess 34a in the short axis direction of the bale shape, and a second locking portion 36b that prevents the second bulging portion 31b from slipping out of the circular hole 35 is formed on the opening edge of the second fitting recess 34b in the short axis direction of the bale shape. Hereinafter, the first locking portion 36a and the second locking portion 36b are collectively referred to as locking portion 36. A protrusion 37 that engages with the recess 32 is formed on the inner peripheral surface of the circular hole 35. The recess 32 and the protrusion 37 function as positioning means.

As shown in FIG. 7, to connect the first fitting protrusion 29a of the first connector 22a and the first fitting recess 34a of the connecting member 23, the first fitting protrusion 29a is inserted into the first fitting recess 34a and rotated 90 degrees in one direction relative to the connecting member 23. Then, the recess 32 of the first fitting recess 34a engages with the protrusion 37 in the circular hole 35 and is positioned. Also, to connect the second fitting protrusion 29b of the second connector 22b and the second fitting recess 34b of the connecting member 23, the second fitting protrusion 29b is inserted into the second fitting recess 34b and rotated 90 degrees in one direction relative to the connecting member 23. Then, the recess 32 of the second fitting recess 34b engages with the protrusion 37 in the circular hole 35 and is positioned. As a result, the first end 17 and the second end 18 are connected by the connecting part 21. When the first connector 22a and the second connector 22b are connected to the connecting member 23, they have approximately the same size and shape as the other metal balls 16a. This forms an endless ball chain 16.

Next, the operation of the roller blind 10 configured as above will be described.
In the ball chain 16 configured in this manner, the distance between the linking portion 21 (a ball having a notch 28 disposed on both sides of the linking member 23) and the metal ball 16a adjacent to the linking portion 21 is the same as the distance between adjacent metal balls 16a at a position not including the linking portion 21. Therefore, the ball chain 16 can rotate around the pulley 15 without any restrictions.

When the first connector 22a and the second connector 22b are connected to the connecting member 23, the first bulge 31a of the first fitting protrusion 29a is engaged with the first locking portion 36a and held in the circular hole 35. The second bulge 31b of the second fitting protrusion 29b is engaged with the second locking portion 36b and held in the circular hole 35. This locked state is positioned by the protrusion 37 engaging with the recess 32, and further by the engagement of the rib 33 with the protrusion 37. This holding force is set so that the fitting protrusion 29 will not come off the fitting recess 34 with the normal tensile force acting on the ball chain 16 during normal lifting and lowering of the screen 12.

Only when a tensile force greater than the normal tensile force acts on the ball chain 16, the elasticity of the synthetic resin of the locking portion 36 of the connecting member 23 causes the expanded diameter portion 31 to push the mating recess 34 wider, and the mating protrusion 29 comes out of the mating recess 34.

The first embodiment as described above can provide the following advantages.
(1) By connecting the connector 22 to the connecting member 23 at the connecting portion 21, the fail-safe function of the metal ball chain 16 can be achieved in the same way as a resin ball chain.

(2) The fitting protrusion 29 is inserted into the fitting recess 34 and rotated 90 degrees to engage the expanded diameter portion 31 with the engaging portion 36. This allows the force required to fit the fitting protrusion 29 into the fitting recess 34 to be slight, while still providing sufficient holding force to hold the fitting protrusion 29 in the connecting member 23.

(3) After the connecting portion 21 has been disengaged, the endless ball chain 16 can be easily regenerated by re-engaging the engaging protrusion 29 of the connector 22 with the engaging recess 34 .
(4) Since the operating force required to fit the fitting protrusion 29 into the fitting recess 34 is slight, the fitting protrusion 29 can be easily refitted into the fitting recess 34. Therefore, even if the connecting portion 21 becomes detached, the resident can easily return it to its original position.

(5) The distance between the metal balls 16a other than at the connecting portion 21 is the same as the distance between the connecting portion 21 (when the first connector 22a and the second connector 22b are connected to the connecting member 23) and the adjacent metal ball 16a. Therefore, the ball chain 16 can rotate around the pulley 15 without any restrictions.

(6) The projection 37 engages with the recess 32 of the expanded diameter portion 31. This positions the mating protrusion 29 in a state in which the expanded diameter portion 31 is locked with the locking portion 36. In other words, it is possible to prevent the mating protrusion 29 from accidentally rotating and coming off the mating recess 34 during use.

(7) The link shaft 26 and the resin fitting portion 27 can be easily integrated together by insert molding.
(8) The link shaft 26 includes the integrated portion 26 b. Since the resin flows into the integrated portion 26 b, the link shaft 26 is less likely to come out of the resin fitting portion 27 .

(9) The integrated portion 26b is provided with an enlarged diameter portion having a flange shape that is continuous in the circumferential direction, so that it can be integrated with the resin fitting portion 27 more firmly.
(10) The retaining portion 26 c can couple the metal ball 16 a to the connector 22 more strongly than the coupling of the connector 22 to the coupling member 23 .

(11) The connecting member 23 is made of a resin material, and therefore is easy to manufacture.
Second Embodiment
8 and 9, the link shaft 41 includes a metal shaft portion 41a, a first integrated portion 41b provided at one end of the metal shaft portion 41a, and a retaining portion 41c for the metal ball 16a. The first integrated portion 41b is a convex portion that protrudes in the outer circumferential direction and is discontinuous in the circumferential direction. The resin fitting portion 27 is formed by insert molding one end of the link shaft 41 including the first integrated portion 41b. With this configuration as well, the link shaft 41 can be integrated with the resin fitting portion 27 more firmly.

The other end of the metal shaft portion 41a is also provided with a second integrated portion 41d. In this embodiment, the retaining portion 41c is a molded portion of synthetic resin. For example, the retaining portion 41c is a molded portion made of synthetic resin material such as polyester, polypropylene, or polyacetal. The retaining portion 41c is a resin enlarged diameter portion whose surface on the metal shaft portion 26a side has an inclined surface or a spherical shape corresponding to the inner surface of the metal ball 16a. The second integrated portion 41d is a convex portion having a configuration similar to that of the first integrated portion 41b, but has a shape rotated 90 degrees with respect to the first integrated portion 41b. The retaining portion 41c is formed by insert molding the other end of the link shaft 41 provided with the second integrated portion 41d. With this configuration, the link shaft 41 can be more firmly integrated with the retaining portion 41c. Since the first integrated portion 41b and the second integrated portion 41d have the same configuration, either one may be used as the integrated portion for the resin fitting portion 27, or may be used as the integrated portion for the retaining portion 41c.

Third Embodiment
As shown in FIG. 10 and FIG. 11, the link shaft 46 is a metal screw member, and includes a shaft portion 46a, a threaded portion 46b provided on one end side of the shaft portion 46a, and a screw head 46c provided on the other end side of the shaft portion 46a. The threaded portion 46b is a screw groove formed of a spiral groove, and is a concave portion and a convex portion. Therefore, the threaded portion 46b functions as an integrated portion with respect to the resin fitting portion 27. The threaded portion 46b may be provided on the tip side of the shaft portion 46a as shown in the figure, or may be provided over the entire length of the shaft portion 46a. The screw head 46c is a metal enlarged diameter portion that functions as a retaining portion for the metal ball 16a. The screw head 46c has an engagement groove, such as a + groove or a - groove, on its top surface, with which a tool such as a screwdriver engages. The link shaft 46 can be integrated with the resin fitting portion 27 by screwing the threaded portion 46b into the resin fitting portion 27, or can be integrated with the resin fitting portion 27 by insert molding.

Fourth Embodiment
As shown in FIG. 12, the connecting portion 51 includes a first connector 22a constituting the first end 17, and the first connector 22a includes a link shaft 46 and a resin fitting portion 27 as a fitting portion. In contrast, the second connector 22b constituting the second end 18 includes a resin fitting portion 52 as a fitting portion. The link shaft 46 can be integrated with the resin fitting portion 52 by screwing the screw portion 46b into the resin fitting portion 52, or can be integrated with the resin fitting portion 52 by insert molding. Note that the link shaft 46 can be configured the same as the link shaft 26 instead of a metal screw member. The resin fitting portion 52 is a part that replaces the connecting member 23, and includes a fitting recess 53 on a first plane facing the first connector 22a side. The fitting recess 53 is formed in a bale shape into which the tip portion including the expanded diameter portion 31 of the fitting protrusion 29 can be inserted. The fitting recess 53 allows the fitting protrusion 29 to rotate inside. The opening edges of the fitting recess 53 in the short axis direction of the bale shape are each formed with a locking portion 54 that prevents the expanded diameter portion 31 from coming out of the fitting recess 53 .

To connect the first mating protrusion 29a of the first connector 22a and the resin mating portion 52 of the second connector 22b, the mating protrusion 29 is inserted into the mating recess 53 and rotated 90 degrees in one direction relative to the mating recess 53. In other words, this is the same as the method of connecting the mating protrusion 29 to the connecting member 23 in the first embodiment. With this configuration, the number of parts can be reduced because no connecting member is used, as in the first to third embodiments.

The first to third embodiments described above can be further modified as follows.
The connecting member 23 may be a resin molded body that is covered with a metal cover.

The integrated portion may be outsert molded onto the resin fitting portion.
The shape of the integrated portion is not particularly limited as long as it protrudes in the outer circumferential direction relative to the shaft portion.

The resin fitting portion 27 and the fitting recess 53 may be formed of metal instead of resin.
The link shaft 26 and the link shaft 41 do not have to be made of metal, but may be made of resin.

- The resin fitting portion 27, the fitting recess 53, the link shaft 26, and the link shaft 41 may be made of diamond or the like to improve the design. The link shaft 26 and the link shaft 41 are made of a material harder than the resin fitting portion 27 and the fitting recess 53 or the same material as them.

The ball chain may be a resin ball chain instead of a metal ball chain. In this case, too, in the fitting portion that constitutes the first connector portion and the second connector portion that constitute the connecting portion, an integrated portion for the resin fitting portion may be provided on the resin or metal link shaft that is integrated with the resin fitting portion. Also, in the resin link shaft that connects the resin ball portions in place of the metal balls 16a, an integrated portion may be provided to prevent the ball portions from coming loose.

- The metal link shaft 16b and flange portion 16c of the metal ball chain may be provided separately, and an integrated portion may be provided at the end of the metal link shaft 16b to prevent the metal link shaft 16b from coming loose from the resin flange portion 16c.

- As shown in FIG. 13, the link shaft 26 may have an integrated portion 26x at its end, which is made up of a recess. In this case, the integrated portion 26x is made up of a recess, i.e., a groove, that continues in the circumferential direction at the end of the metal shaft portion 26a. With this configuration, the metal shaft portion 26a and the resin fitting portion 27 can be firmly integrated by allowing resin to enter the groove.

- As shown in FIG. 14, the link shaft 26 may have an integrated portion 26y at its end, which is configured as a through hole as a recess. In this case, the integrated portion 26y is configured as a recess that penetrates radially, i.e., a through hole, at the end of the metal shaft portion 26a. Even with this configuration, the metal shaft portion 26a and the resin fitting portion 27 can be firmly integrated by the resin entering the through hole.

-Shading devices using the ball chain 16 can be not only roller blinds, but also horizontal blinds, vertical blinds, etc. The ball chain 16 is used as an operating cord to open and close these shading materials such as slats and screens.

10...Roller screen 16...Ball chain 16a...Metal ball 16b...Metal link shaft 17...First end 18...Second end 21...Connecting portion 22a...First connector 22b...Second connector 23...Connecting member 26...Link shaft 26a...Metal shaft portion 26b...Integrated portion 26c...Prevention portion 27...Resin fitting portion 28...Spherical recess 29a...First fitting protrusion 29b...Second fitting protrusion 31a...First expanded portion 31b...Second expanded portion 34a...First fitting recess 34b...Second fitting recess 36a...First locking portion 36b...Second locking portion

Claims (4)

A ball chain is a chain of metal balls connected by metal link shafts, and the ends of the ball chain are connected to each other by a connecting part to form a ring.
the coupling portion includes a connector at each of the ends;
Each of the connectors includes a link shaft and a fitting portion that is a resin molded portion provided on the link shaft,
the link shaft includes a metal shaft portion, an integration portion for integration with the fitting portion provided at one end of the metal shaft portion , and a retaining portion for coupling with the metal ball provided at the other end of the metal shaft portion,
A ball chain, wherein the integrated portion includes a protrusion or a recess. The ball chain according to claim 1 , wherein the integrated portion is an enlarged diameter portion. When a tensile force exceeding that during normal operation is applied to the ball chain, the connectors of the connecting portion are separated from each other.
The ball chain according to claim 1 or 2. The surface of the fitting portion has an appearance similar to that of the metal ball.
A ball chain as claimed in any one of claims 1 to 3 .