JP4697680B2 - Footwear tip - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tip used for protection of a fingertip portion by being attached to a footwear toe portion such as a shoe, a boot, or a basement.
[0002]
[Prior art]
Some work shoes, called safety boots and safety boots, or some footwear such as basements have metal tips to protect the toes from falling objects .
However, since the tip used conventionally has been focused on covering the fingertip portion, it is not always in a shape that easily resists an external force caused by a fallen object or the like.
[0003]
For example, the tip 100 shown in FIG. 12 is an example, and has a shape that covers the toe portion of the foot as a whole, a top portion 101 that curves upward, a leading end that is connected to this, and rising portions 102, 103, 103 on both sides. Thus, the whole is formed in a curved surface so as to have a substantially semi-dome shape, and a flange portion 104 is connected to the lower end.
[0004]
When a force is applied to the tip 100 by the object X from above as shown in FIG. 13, the tip core 100 is deformed from the top portion to the rising portion, and further, stress concentrates on a specific portion to cause destruction. It will happen that the purpose of the period is not fully achieved.
That is, when the tip 100 is placed on a flat surface as shown in FIG. 13A and a force is applied by the object X having a flat lower end, the top 101 is first crushed and flattened as shown in FIG. 13B. Begin to become. At this time, since the top portion 101 of the curved cross section becomes flat, the material of the top portion 101 tends to extend to the outside. However, a force against this works due to the presence of the surrounding rising portion and flange portion. The part becomes a dent of the top part 101, and the rest is used to cause the rising parts 103 , 103 on both sides to fall outward. When further force is applied, the rising portions 103 and 103 fall down as shown in FIG. 13C, and the curvature of the bent portion 105 is reduced, causing this portion to bend and break. The crack will be destroyed. In this case, the tip core 100 is concentrated by the external force applied to the fractured portion, and becomes the limit of the resistance force.
When this state is seen in the cross-sectional view in the lateral direction of FIG. 13D, the tip portion of the tip 100 is strong because the three directions are rising portions, but the rising portions 103 and 103 on both sides are outward. The top 101 of the opening at the rear end is pushed down from the position indicated by the arrow Y, and the desired space cannot be maintained.
[0005]
[Problems to be solved by the invention]
In order to prevent the strength reduction and deformation of the tip as described above, it has been conventionally necessary to increase the overall thickness or select a material with higher strength, but this increases the weight of the tip. However, there is a problem that the molding process becomes difficult, or the material cost increases and the cost increases.
Therefore, the present inventor has a shape that covers the fingertip in order to suppress deformation due to external force as much as possible without particularly increasing the wall thickness, and includes a top portion, a surrounding rising portion, and a shoulder portion that connects the two portions. The rising part is formed so that the cross-section of the head is slightly curved upward or is substantially linear, and the surrounding rising part can receive the force applied to the top part substantially uniformly. We have already proposed a toe for footwear characterized by (Japanese Patent Application No. 10-343514)
[0006]
FIG. 9 and FIG. 10 show the shape of the tip for footwear according to the above proposal, and are a perspective view and a rear view as seen from the rear opening side. In the figure, 11 is a top portion, and its cross section is slightly curved upward or is formed in a substantially straight shape so as to cover the upper part of the fingertip, 12 is a rising portion at the tip, and 13 and 13 are rising portions on both sides. These rising portions 12, 13, and 13 surround the toe portion. Reference numeral 14 denotes a shoulder connecting the top 11 and the rising parts 12, 13, 13. In this example, the tip portion of the top portion 11 is formed so that the curvature is small and substantially linear, and the curvature from the opening portion 17 toward the rear end portion gradually increases. In the figure, reference numeral 15 denotes a flange portion connected to the lower ends of the surrounding rising portions 12, 13, and 13.
[0007]
When such a tip is placed on a flat surface as in FIG. 13 and a force is applied from above from the object X, the top 11 is extended outward and flat, unlike the case of 13 (B). As a result, the rising portions 13 and 13 on both sides that have been inclined become substantially vertical, and the shoulder 14 that connects the two portions is also in a right-angled state, so that the whole has a substantially rectangular cross section. On the other hand, the rising portion 12 at the tip is not as large as the other portions, and has substantially the same height as the rising portions 13 and 13 on both sides, and this section also has a rectangular shape.
In such a state, the surrounding rising portions 12, 13, and 13 receive the force applied to the top portion 11 substantially simultaneously, that is, substantially uniformly, and the force is applied uniformly to the whole. You will be able to balance the front and back.
[0008]
When further force is applied from this state, the force applied to the top portion 11 and the shoulder portion 14 is applied to the entire rising portions 12, 13, and 13, and the curvature of the shoulder portion 14 hardly changes, so that it can withstand without causing stress concentration. . When force is further applied, the rising parts 12, 13, and 13 are swollen outward and buckled, but at this stage, the load applied to the tip is received by the whole rising part. Therefore, the strength is greatly increased as compared with the tip of the same thickness and the same material without causing a deformation such that the opening at the rear end falls as in the conventional product.
[0009]
By the way, when a vertical load is applied to the tip by the object X and the rising portions 12, 13, 13 receive the load, the top portion 11 has a substantially rectangular cross section and can be received substantially uniformly. As a result of further studies, it was found that the original compressive stress of the material could not be fully exerted due to the phenomenon described below.
[0010]
This phenomenon will be described with reference to FIG. 11. FIG. 11 (A) partially shows the rising portion 13 and the shoulder portion 14 of FIG. In order to facilitate foot placement and to avoid foot contact, the tip 11 has the top 11 curved in the direction. When a vertical load of the object X is applied to this part from above, the shoulder as shown in FIG. The portion 14 is deformed at a substantially right angle. At this time, the shoulder portion 14 undergoes internal destruction due to deformation and generates a fine crack. At the same time, the flange portion 15 is also slightly lifted, the contact area is reduced, the surface pressure is increased, and a crack is also generated therein. This is because a vertical load is applied to the rising portions 12, 13, and 13 in this state, so that stress concentrates on these cracks, and the rising portions 12, 13, and 13 are liable to cause compression failure.
[0011]
In view of such a phenomenon, the present invention forms the rising portion so that the force applied to the top portion can be received substantially uniformly by the surrounding rising portion in order to provide a tip having superior strength. At the same time, when a vertical load is applied to the rising portion, the pressure receiving surfaces are positively provided at the upper end and the lower end to achieve the object of the present invention.
[0012]
[Means for Solving the Problems]
That is, the present invention has been made to solve the above-described problems, and the gist of the present invention is that it is a shape that covers the fingertip in a tip made of a hard material that is used by being attached to a footwear fingertip , It consists of a curved top part, a surrounding rising part formed so as to be slightly inclined upward according to the curvature of the top part, a shoulder part connecting both parts, and a flange part at the lower end, and is deformed by the force applied to the top part In the state where it is received, it is configured so that it has a substantially rectangular cross section and the surrounding rising part can be received substantially uniformly, and the rising part on the shoulder part from the shoulder part to the entire circumference of the rising part A flat and narrow upper pressure-receiving surface that is connected to the upper surface, and a shoulder portion on which the upper pressure-receiving surface is formed and the flange portion are formed at a right angle to the rising portion. At the tip.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings showing the embodiments.
FIGS. 1 to 6 show a first embodiment of the present invention, in which FIG. 1 is a perspective view of the footwear core of the present invention as seen from the rear opening side, and FIG. 2 is from the same direction. FIG.
In the figure, reference numeral 1 denotes a top portion which is formed so that the cross section thereof is slightly curved upward and substantially covers the top of the toe portion, 2 is a rising portion at the tip, 3 is a rising portion on both sides, These rising portions 2, 3, 3 surround the toe portion so as to cover the fingertips. Reference numeral 4 denotes a shoulder portion connecting the top portion 1 and the rising portions 2, 3, 3, and this tip can receive the force applied to the top portion 1 substantially uniformly at the surrounding rising portions 2, 3, 3. It is like that. Rising portions 2,3,3 in this case is curved to the top 1 upward as shown, formed as depending on degree of curvature of the upward the top 1 cross-section, inclined slightly directed upward inside then well, the inclination angle in consideration of the degree of curvature of the top portion 1, the curvature is determined by equally also to increase the inclination angle is larger. In the figure, 6 is a flange portion at the lower end of the rising portions 2, 3 and 3, and 7 is a rear opening. A fillet portion 8 having a curvature R on the inner surface is provided at the inner corner of the upper pressure receiving surface 5 and the inner corner of the flange portion 6.
[0014]
In the present invention, such a tip is a flat and narrow upper pressure receiving member connected to the shoulder portion 4 in at least a part of the configuration from the shoulder portion 4 to the rising portions 2, 3, 3. In this example, the upper pressure-receiving surface 5 is formed along the entire circumference of the rising portions 2, 3, and 3. In this example, the shoulder portion 4 and the flange portion 6 are formed at right angles to the rising portions 2, 3 and 3.
[0015]
A state in which a vertical load is applied to the tip from above will be described in the same manner as in FIG. 13 described above. FIG. 3 (A), FIG. 4 (A), and FIG. 3 (B), FIG. 4 (B), and FIG. 6 (C) are cross-sectional views viewed from a direction perpendicular to this.
As shown in FIG. 3, the tip is placed on a flat surface and a vertical load is applied to the object X from above, but the tip of the present invention has a rising portion 3 on both sides as shown in FIG. The cross section 3 is substantially linear, and is slightly inclined upward according to the curvature of the top portion 1, and the rising portion 2 at the tip is substantially vertical as shown in FIG.
[0016]
FIG. 4 shows a state in which the deformation of the tip due to the vertical load has progressed and the upper pressure-receiving surface 5 is in contact with the object X, the curvature of the top portion 1 is flattened, the rising portion 3 stands vertically, The flange portion 6 also has a right angle and is in contact with a flat surface. As shown in FIG. 5, when the rising portion becomes vertical, the flange portion 6 that is perpendicular to the upper pressure receiving surface 5 becomes the lower pressure receiving surface, and the load is uniformly distributed by the upper and lower pressure receiving surfaces. The load can be received. At the same time, since the bending stress generated in the shoulder portion described above is generated exclusively in the connecting portion S on the inner side, the influence on the upper end of the shoulder portion 4 and the rising portion 3 can be reduced, and the flange at the lower end can be reduced. Since the portion 6 is also in a vertical shape and is in contact with it, the surface pressure is not increased.
As a result, the upper pressure-receiving surface 5 and the flange portion 6 of the rising portion 3 are not broken, receive a vertical force, eliminate stress concentration due to the occurrence of cracks, and maximize the compression of the rising portions 2 and 3. Stress will be exhibited. In particular, in this example, the fillet portion 8 is formed at the inner corner of the upper pressure-receiving surface 5 and the inner corner of the flange portion 6, so that bending stress is not concentrated at this portion, and a more preferable result is obtained. Therefore, it is possible to obtain a tip having a higher strength that does not cause compressive fracture like the tip proposed by the above-described proposal.
[0017]
FIGS. 4 and 6 for explaining the present embodiment show the states corresponding to FIGS. 13B and 13C. In the case of the present invention, FIG. As shown in FIG. 5, the lead core is deformed and has a substantially rectangular cross section so that the load can be received substantially uniformly. When the load is further applied and the state shown in FIG. 6 is reached, the rising portions 2, 3, 3 bulge outward and buckle. At this stage, the load applied to the tip is received by the rising parts 2, 3 and 3 as a whole, so that the rear end opening 8 side is not deformed as in the conventional product, and is the same. Compared to the thickness and the tip of the same material, the strength can be further greatly increased.
[0018]
FIG. 7 shows a second embodiment of the present invention. A flange 9 is provided outside the shoulder 4 and the flange 6 forming the upper pressure receiving surface 5 of the rising parts 2, 3, 3. Formed. This is effective because the pressure applied to the pressure receiving surface can be reduced. Although the flange portion 9 is preferably provided on the shoulder portion 4 outwardly and the flange portion 6 outwardly as shown, be formed only on the shoulder portion 4 outside only or flange portion 6 outward Good.
[0019]
Furthermore, Figure 8 shows a third embodiment of the present invention, in the cross-sectional shape of the rising portion 2,3,3, are formed in a thin-walled than the center portion C to the upper side and the lower side It is characterized by this. If comprised in this way, a stress will be uniformly disperse | distributed to the whole cross section with respect to a vertical load, and a lighter and high intensity | strength tip will be obtained.
In addition, such a thin-walled central portion C can be provided only in a part where the rising portions 2, 3 and 3 are required.
[0020]
Examples of the material for the core used in the present invention include plastics, FRP in which plastics are reinforced with fibers such as glass fibers and carbon fibers, metal materials such as commonly used steel materials, stainless steel, aluminum alloys, and titanium alloys. Can be used. In particular, the present invention is more advantageous because the thickness of the tip can be reduced in order to obtain the same strength.
[0021]
In addition, since the structure of the tip of the present invention has a function of receiving the load applied to the top portion 1 at the surrounding rising portions 2, 3, and 3 and exerting the strength as much as possible, the rising portions 2, 3, It is desirable to increase the strength of 3. From this point of view, it is one effective means to make the rising portions 2, 3, and 3 thicker than other portions.
[0022]
In the embodiment of the present invention, the upper pressure-receiving surface 5 and the flange portion 6 are formed at right angles to the rising portions 2, 3, and 3, so that when a load is applied to the top portion 1, 5 and the flange portion 6 are orthogonal and the rising portions 2, 3 and 3 are vertical, but this angle is not necessarily limited to a right angle. A close effect is obtained.
[0023]
Further, in the above-described embodiment, the fillet portion 8 whose inner surface has a curvature is formed at the inner corner of the upper pressure-receiving surface 5 and the inner corner of the flange portion 6, which is effective in eliminating stress concentration. The shape may be triangular, or the fillet portion 8 may be formed only at the inner corner of the upper pressure-receiving surface 5 or the inner corner of the flange portion 6 to improve stress concentration at that portion.
[0024]
【The invention's effect】
The present invention has a configuration as described in detail above. The surrounding rising portion has a unique configuration, and the pressure receiving surfaces are positively formed at both the upper and lower ends of the rising portion. When it is applied, it exhibits a substantially rectangular shape in a deformed state, and it can be received almost uniformly in a well-balanced manner all around the rising part, and exerts strength, especially on the pressure-receiving surface of the rising part. Can suppress the occurrence of compressive fracture due to, and can exhibit even more strength, especially prevent deformation due to the drop of the opening at the rear end, can receive the load in a balanced manner as a whole, the same thickness The strength is higher than that of the tip using the same material. Therefore, in order to obtain a predetermined strength, the thickness can be reduced to reduce the weight. The There is an advantage that can be reduced.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view of a footwear core according to a first embodiment of the present invention as viewed from the opening side.
2 is a cross-sectional view seen from the opening side of the tip of FIG.
FIG. 3 is an explanatory view showing a state in which an external force is applied to the tip of the present invention. FIG. 3 (A) is a cross-sectional view seen from the opening end side, and FIG. FIG. 4 is an explanatory view showing a state in which an external force is to be applied to the tip of the present invention. FIG. 4 (A) is a cross-sectional view seen from the opening end side, and FIG. FIG. 5 is a partial cross-sectional view showing a state of a rising portion when a force is applied to the tip of the present invention.
6A and 6B are explanatory views showing a state in which an external force is further applied to the tip of the present invention to cause buckling, in which FIG. 6A is a cross-sectional view seen from the opening end side, and FIG. It is sectional drawing seen from the side.
FIG. 7 is a partial cross-sectional view of a tip for footwear showing a second embodiment of the present invention.
FIG. 8 is a partial cross-sectional view of a tip for footwear showing a third embodiment of the present invention.
FIG. 9 is a perspective view showing an example of a lead core previously proposed by the present inventor.
10 is a rear view of the lead core shown in FIG. 9 as viewed from the opening side.
11 is a drawing for explaining the function of the lead core shown in FIGS. 9 and 10. FIG.
FIG. 12 is a perspective view showing a conventional tip for footwear.
13 is an explanatory view showing a state where an external force is applied to a conventional tip, FIG. 13 (A) is a side view of the state where an external force is about to be applied, as viewed from the rear end side, and FIG. 13 (B) is an external force. 13C is a side view of a state in which a part has started to be applied, FIG. 13C is a side view of a part in which a part is further broken by applying an external force, and FIG. 13D is a cross section of the state of FIG. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Top part 2 Rising part 3 (on the front end) 3 3 Rising part 4 (on both sides) Shoulder part 5 Upper pressure-receiving surface 6 Flange part 7 Opening part 8 Fillet part 9 Gutter part

Claims (4)

The tip of the hard material that is used by being attached to the foot part of the footwear is a shape that covers the fingertip, and has a top part that is curved upward, and a peripheral part formed so as to be slightly inclined upward according to the curvature of the top part. It consists of a rising part, a shoulder part that connects both parts, and a flange part at the lower end, and it has a substantially rectangular shape in a state where it is deformed by the force applied to the top part, and the surrounding rising part can be received almost uniformly. A shoulder that is configured to be capable of being formed and has a flat and narrow upper pressure-receiving surface connected to the rising portion on the shoulder from the shoulder portion to the entire circumference of the rising portion, and further forming an upper pressure-receiving surface. The tip for footwear is characterized in that the portion and the flange portion are formed substantially perpendicular to the rising portion. The tip for footwear according to claim 1, wherein a fillet portion is formed at an inner corner of the upper pressure receiving surface and / or an inner corner of the flange portion. The tip for footwear according to claim 1 or 2, wherein a heel portion is formed outside the shoulder portion and / or the flange portion. 4. The tip for footwear according to claim 1, wherein, in the cross-sectional shape of the rising portion, the central portion is formed thinner than the upper and lower portions.

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