JP2001245717A - Umbrella rib - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an umbrella rib which satisfies the freedom and easiness in processing, the reduction of the weight, and a high strength, and in addition, is excellent in elastic flexibility to realize a desired beautiful arc-shape deformation when the umbrella is opened, and fatigue-resistance. SOLUTION: In this umbrella rib which can bend-deform into an arc-shape by the tension of an umbrella fabric, on the upper surface of a rib body which is integrally molded of a fiber-reinforced resin, an upper groove extending in the longitudinal direction, and upper rib walls which constitute both side walls of the upper groove are formed. At the same time, on the lower surface of the rib body, a lower groove extending in the longitudinal direction and lower rib walls which constitute both side walls of the lower groove are formed. Then, the length DL of the lower groove to the length UL of the upper groove is formed in a manner to satisfy UL>DL.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an umbrella bone constituting a frame structure of a western umbrella.

[0002]

2. Description of the Related Art Conventionally, umbrella bones were mainly made of steel, but those made of a light alloy such as aluminum have been provided for weight reduction. However, since aluminum has poor toughness, umbrella bones formed of lightweight and high-strength resin have recently been provided.

[0003]

The umbrella bone made of synthetic resin is
It satisfies the freedom and ease of processing by injection molding and the weight reduction, but has drawbacks in strength. In particular, in the rib of the western umbrella, it is necessary to be able to bend and deform in an arc shape due to the tension of the umbrella cloth. When the property is required, there is a problem that it is easily broken at the time of bending deformation, and there is also a problem with fatigue resistance.

Therefore, in recent years, umbrella bones have been formed using a fiber reinforced resin reinforced with short fibers such as glass fiber or carbon fiber.
Although it exhibits high strength against compressive stress, it has low strength against tensile stress, and still has many problems to be solved.

[0005]

SUMMARY OF THE INVENTION The present invention provides an umbrella bone which solves the above-mentioned problems while being integrally molded with a fiber reinforced resin reinforced with short fibers such as glass fiber and carbon fiber.

Therefore, the present invention is configured as a first means, in an umbrella bone capable of being curved and deformed in an arc shape by the tension of an umbrella cloth, extending longitudinally on the upper surface of a bone body integrally formed of fiber-reinforced resin. An upper groove and upper rib walls forming both side walls of the upper groove are formed, and a lower groove extending in the longitudinal direction and lower rib walls forming both side walls of the lower groove are formed on the lower surface of the bone body, and the length of the upper groove is formed. The length DL of the lower groove with respect to UL is
UL> DL.

Further, the present invention is constituted as a second means, in that a main rib to be pivotally connected to the fixed wheel, an intermediate rib to be pivotally connected to the main rib, and a main rib to be pivotally connected to the intermediate rib. In the frame structure of the folding umbrella provided with the rib, the intermediate rib is integrally formed of a fiber-reinforced resin, and forms an upper groove extending in a longitudinal direction on an upper surface of the intermediate rib and upper rib walls forming both side walls of the upper groove. Together, a lower groove extending in the longitudinal direction on the lower surface and lower rib walls forming both side walls of the lower groove are formed,
Do not match both ends of the upper groove with both ends of the lower groove,
Moreover, the length DL of the lower groove with respect to the length UL of the upper groove
Is configured to satisfy UL> DL.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 show, as an example of a umbrella, a frame structure of a known folding umbrella which enables an automatic umbrella.

A retractable multi-stage center rod 1 is provided with a spring mechanism, not shown, which is slidable up and down with respect to a fixed wheel 2 fixed to the upper end of the center rod 1. A sliding wheel 3 is externally inserted into the center rod 1, and the sliding wheel 3 is fixed to the fixed wheel 2 via a rope such as a string (not shown).
Is connected to the internal spring mechanism from the vicinity of. Therefore, when the multi-stage center rod 1 is contracted to accumulate a compressive force in the spring mechanism, when a button (not shown) is pressed in the opening direction, the center rod 1 is extended by the spring mechanism and the sliding wheel is rotated. 3 is pulled up by a cable and automatically opened as shown in FIG. From this open state, if you push a button (not shown) in the closing direction, the cable will be loosened,
As shown in FIG. 2, the sliding wheel 3 is lowered while the frame structure is automatically closed. Fig. 2
Is performed by the tension spring 4 and the connecting wire 5 shown in FIG. Therefore, after the automatic closing, the inner rod 1 is contracted again and the compressive force is accumulated in the spring mechanism, so that the automatic opening and closing can be performed again.

A main rib 6 is pivotally attached to the fixed wheel 2.
An intermediate rib 7 is pivotally attached to the tip of the main rib 6, and a leading rib 9 is pivotally attached 10 to the tip of the intermediate rib 7. A supporting bone 11 is pivotally attached to the sliding wheel 3, and a distal end of the supporting bone 11 is pivotally connected 12 to a middle part of the main rib 6 in the longitudinal direction. Further, the vicinity of the distal end of the supporting bone 11 and the proximal extension 13 of the intermediate rib 7 are connected by a connecting bone 14, and both ends of the connecting bone 14 are pivotally connected 15 to the supporting bone 11 and the intermediate rib 7, respectively. 16 As shown in FIG. 2, the above-described tension spring 4 is stretched between a portion near the proximal end of the connecting bone 14 and a portion near the distal end of the main rib 6. The extension spring 4 is constituted by an extension coil spring. The connecting line 5 is provided between the annular portion 17 provided near the distal end of the main rib 6 and the proximal extension 18 of the leading rib 9, and the connecting line 5 is connected to the longitudinal direction of the intermediate rib 7. It is slidably inserted into and held by a guide 19 provided in the middle part. The connecting wire 5 is made of an elastically deformable steel wire.

Therefore, when the sliding wheel 3 rises and the main ribs 6 are pushed up by the support bones 11 during the automatic opening of the umbrella, as shown in FIG. The main ribs 9 are moved so as to be aligned with each other so as to be aligned with the extension line of the intermediate rib 17 by the connecting line 15. Conversely, when the sliding wheel 3 is released from the lifting force during the automatic closing operation, as shown in FIG. 2, the connecting bone 14 is slid while being moved in parallel in a direction away from the main rib 6 by the tension spring 4. Lower the potter's wheel 3. At this time, the intermediate rib 7 is interlocked with the connecting bone 14 so as to erect the tip, and further, the connecting rib 15 is interlocked with the tip rib 9 so as to hang down the tip.

In the frame structure shown in the figure, an umbrella cloth is stretched from the base end of the main rib 6 to the tip of the front rib 9, so that the main rib 6, the middle rib 7, and the front rib 9 draw a gentle arc. Curved. Therefore, in the case of the illustrated example, it is desirable to carry out the present invention on the intermediate rib 7,
Is integrally formed of a fiber reinforced resin reinforced by short fibers such as glass fiber and carbon fiber, and is curved and deformed in an arc between the pivot portions 8 and 10 at both ends when the umbrella is opened. Hereinafter, the bone of the embodiment in which the present invention is applied to the intermediate rib 7 will be described as a bone 7.

As shown in FIGS. 3 and 4, the bone body 7 is integrally formed to have a substantially rectangular cross section, and has a tapered dowel portion 20 having a tapered tip for forming a pivotal connection portion 10 to the tip rib 9.
And a bifurcated proximal extension 13, 13 for forming a pivotal connection 16 to the connecting bone 14.
In the vicinity of 3, there are provided forked bracket portions 21, 21 for forming a pivotal connection portion 8 to the main rib 6.

An upper groove 22 extending in the longitudinal direction and upper rib walls 23, 23 constituting both side walls of the upper groove are formed on the upper surface of the bone body 7, and the upper groove 22 is formed from the vicinity of the dowel 20. It has a length UL reaching the end face of the end extension 13, 13.
In the case of the illustrated example, the upper groove 22 includes a shallow groove portion 22a in the middle part of the bone body 7 in the longitudinal direction, a deep deep groove portion 22b from the shallow groove portion 22a to a groove end toward the dowel portion 20, and a bracket portion 21 from the shallow groove portion 22a. A deep deep groove 22c up to the vicinity;
A deepest groove portion 22d which is further deepened from the deep groove portion 22c to the end face of the base extension portions 13, 13 is formed. Also,
The upper rib walls 23, 23 are located on both sides of the shallow groove 22a, the thin ribs 23b located on both sides of the deep groove 22b, and located on both sides of the deep groove 22c and the deepest groove 22d. And a thin rib portion 23c, which is provided with the base extension portions 13, 13 and the bracket portion 21,
21 extends with substantially the same thickness as the thin rib portion 23c.

A lower groove 24 extending in the longitudinal direction and lower rib walls 25 constituting both side walls of the lower groove are formed on the lower surface of the bone body 7, and the lower groove 24 corresponds to the shallow groove portion 22a. And has a length DL. The lower rib walls 25, 25 are provided with cutouts 26, 26 for fitting the guides 19 described above.

Therefore, the bone body 7 is formed with an upper groove 22 and a lower groove 24 at the top and bottom, but as shown in FIG.
Are not aligned with both ends of the lower groove 24, and the length DL of the lower groove 24 relative to the length UL of the upper groove 22
Is configured to be UL> DL.

To clarify the operation of the present invention, FIG.
The following describes a comparative example. First, in the first comparative example of FIG. 5A, the length UL of the upper groove 22 and the length DL of the lower groove 24 of the bone body 7 are set to UL = DL. As a result of the formation of the upper and lower grooves, the bone body 7 is appropriately curved and deformed as shown by the chain line when the umbrella is opened. Bottom wall 2
There is a possibility that stress is concentrated on both end portions 28, 28 of the 7, and cracks are easily generated and breakage occurs.

Next, in a second comparative example shown in FIG. 5B, the length UL of the upper groove 22 and the length DL of the lower groove 24 of the bone body 7 are expressed by U
L <DL. Since the bone body 7 also has the upper and lower grooves, it can be suitably curved and deformed as shown by a chain line when the umbrella is opened. Unlike the first comparative example, since both end positions of the upper groove 22 and both end positions of the lower groove 24 do not coincide with each other, breakage at both end portions of the bottom wall portion 27 between the upper and lower grooves is prevented. However, if a tensile stress acts on the rib wall 23 of the upper groove 22 and a compressive stress acts on the rib wall 25 of the lower groove 24 during the bending deformation, the rib wall 23 of the upper groove 22 may be easily cracked. As mentioned above, fiber reinforced resin
It shows high strength against compressive stress but weak strength against tensile stress. Therefore, the upper rib wall 23 formed short by the length UL cannot withstand the tensile stress, and is easily cracked.

Therefore, according to the present invention shown in FIG. 5C, the length UL of the upper groove 22 and the length DL of the lower groove 24 of the bone body 7 are determined.
Are set to UL> DL. Since the bone body 7 has the upper and lower grooves, the bone body 7 is appropriately curved and deformed as shown by a chain line when the umbrella is opened. Further, unlike the first comparative example described above, since the both end positions 22e, 22e of the upper groove 22 and the both end positions 24e, 24e of the lower groove 24 do not coincide with each other, breakage at both end portions of the bottom wall portion 27 between the upper and lower grooves is required. To prevent. At the time of bending deformation, tensile stress acts on the rib wall 23 of the upper groove 22 and compressive stress acts on the rib wall 25 of the lower groove 24.
As described above, the fiber reinforced resin has a low strength against tensile stress, but has a high strength against compressive stress, so that both the upper and lower rib walls 23 and 25 can endure strongly and do not generate cracks. That is, the upper rib wall 23 subjected to the tensile stress
Is formed longer by the length UL of the upper groove 22, the tensile stress per unit area is small, and the stress is dispersed or absorbed. On the other hand, since the lower rib wall 25 has high strength against compressive stress, no crack is generated even if it is relatively short.

Further, as shown in FIG. 3 and FIG. 4, by forming the upper groove 22 to be longer, the deep groove portion 22b, the shallow groove portion 22a,
22c or the deepest groove portion 22d or the thick rib portion 23a
Since the thin rib portions 23b and 23c can be formed, it is advantageous in that the degree of freedom in design increases when designing what kind of arc shape the bone body 7 is to be curved and deformed.

[0022]

According to the present invention, the bone body 7 is integrally molded with a fiber reinforced resin reinforced by short fibers of glass fiber or carbon fiber, so that the flexibility and easiness of processing by injection molding and the weight are improved. Can satisfy the weight reduction and strength. An upper groove 22 extending in the longitudinal direction on the upper surface of the bone body 7 and upper rib walls 2 forming both side walls of the upper groove.
3 and 23, and a lower groove 24 extending in the longitudinal direction on the lower surface of the bone body 7 and lower rib walls 25 forming both side walls of the lower groove. Arc-shaped deformation can be enabled.

At this time, the fiber reinforced resin has high strength against compressive stress, but has low strength against tensile stress, which has a problem in this point. Is characterized in that the length DL is configured such that UL> DL. That is, at the time of bending deformation, the upper rib wall 23 which receives the tensile stress has a length U of the upper groove 22.
L, the tensile stress per unit area is small, and the stress is dispersed or absorbed. On the other hand, the lower rib wall 25 has a high strength against the compressive stress, so that it is relatively strong. Even if it is short, it does not generate cracks, thereby providing an effect that the bone body 7 having excellent breakage resistance can be provided.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a folded western umbrella using an umbrella bone according to an embodiment of the present invention in an open umbrella state.

FIG. 2 is a front view showing an example of a folded western umbrella using an umbrella bone according to an embodiment of the present invention in an intermediate closing state.

FIG. 3 shows an umbrella bone according to one embodiment of the present invention;
(A) is an enlarged perspective view from a plan view direction, and (B) is an enlarged perspective view from a bottom view direction.

FIG. 4 is a longitudinal sectional view showing an umbrella bone according to one embodiment of the present invention.

5A and 5B show the action of an umbrella bone, where FIG. 5A is a longitudinal sectional view showing a first comparative example, FIG. 5B is a longitudinal sectional view showing a second comparative example,
(C) is a longitudinal sectional view showing the present invention.

[Explanation of symbols]

 2 Fixed wheel 3 Sliding wheel 6 Main rib 7 Intermediate rib 7 (Bone) 9 Front rib 13 Base extension 21 Bracket 22 Upper groove 22a Shallow groove 22b, 22c Deep groove 22d Deepest groove 23 Upper rib wall 23a Thick rib 23b , 23c Thin rib part 24 Lower groove 25 Lower rib wall

Claims (2)

[Claims] In an umbrella bone capable of being curved and deformed in an arc shape by the tension of an umbrella cloth, an upper groove extending in a longitudinal direction on an upper surface of a bone body integrally formed of a fiber-reinforced resin and upper rib walls constituting both side walls of the upper groove. And a lower groove extending in the longitudinal direction and lower rib walls forming both side walls of the lower groove are formed on the lower surface of the bone body, and the length DL of the lower groove with respect to the length UL of the upper groove is formed.
Characterized in that: UL> DL. 2. A folding western umbrella skeleton structure comprising: a main rib attached to a fixed wheel, an intermediate rib attached to the main rib, and a front rib attached to the intermediate rib. The rib is integrally formed of a fiber-reinforced resin, forms an upper groove extending in the longitudinal direction on the upper surface of the intermediate rib, and upper rib walls constituting both side walls of the upper groove, and forms a lower groove extending in the longitudinal direction on the lower surface and the lower groove. Lower rib walls forming both side walls are formed, and both end positions of the upper groove and both end positions of the lower groove do not coincide with each other, and the length DL of the lower groove with respect to the length UL of the upper groove is UL> DL. An umbrella bone comprising: