JPH0524355Y2 - - Google Patents

Description

[Detailed explanation of the idea]

<Industrial Application Field> The present invention relates to oval balls such as rugby balls and footballs. <Prior art> Conventionally, as a thread-wound reinforcing layer for this type of oval ball,
For example, a structure disclosed in Japanese Patent Publication No. 51-10534 is known. The thread-wound reinforcement layer provides the ball with functions such as dimensional stability, shape retention, and durability, and is used in most current ball game balls, such as volleyballs, basketball balls, and soccer balls. It's vaginal discharge. however,
In the case of oval balls such as rugby balls or footballs, it is much more difficult to achieve durability, shape retention, etc. with the thread-wound reinforcing layer than with other spherical balls, and the following problems arise. <Problems to be solved by the invention> In the structure seen in the above-mentioned known example, the thread (first thread) is wound approximately spirally in the short axis direction, and the thread (first thread) is wound in an ∞ shape around both ends of the long axis. The twisted thread (second thread) and
It consists of three types of threads: a thread (third thread) that passes through both ends of the long axis. The first thread is mainly reinforced in the short diameter direction,
The second and third threads are mainly reinforced in the longitudinal direction.
In particular, the third thread running in the major diameter direction is for reinforcing both ends of the major diameter, and the tube surface in this portion has the largest curvature. Therefore, the yarn wound around this part will slip and come off from both ends, making it extremely difficult to provide substantial reinforcement in such a structure. Further, this kind of elliptical ball is normally wound with a thread by rotating both ends of the long axis between a pair of rotating shafts, but according to such a method, it is impossible to wind the thread around both ends. <Means for Solving the Problems> The present invention was made to solve these problems, and includes an elliptical tube, a dish-shaped rubber cap placed on both ends of the long axis of the tube, and a disk-shaped rubber cap covering the tube. It has a thread-wound reinforcing layer, a skin layer made of a rubber or leather panel covering the thread-wound reinforcing layer,
In an elliptical ball formed by winding a part of the thread constituting the thread-wound reinforcing layer around the center of the rubber cap in an area other than the center part of the rubber cap, the thread has a minor axis of the ellipse. Let A, B, C, and D be points that differ every 90 degrees in the circle that includes the rubber cap, and let O and O' be the points at both ends of the long axis that coincide with the center of the rubber cap, then start from point A and move to the surface of one rubber cap. , go around point O, reach two points 270° apart from point A, go around point O′ through the surface of the other rubber cap, reach point C, 270° apart from the two points, and then It goes around point O through the surface of one rubber cap, reaches point C, which is 270° apart from point C, and then passes through the surface of the other rubber cap.
The thread passes through a path that goes around point O' and returns to the vicinity of point A, which is 270° apart from point L, and the thread essentially forms a geodesic curve. <Function> The dish-shaped rubber caps placed on both ends of the tube's long diameter reinforce the ends of the tube where the thread cannot be wound. Since this rubber cap is wound with a thread around the center of the rubber cap in an area other than the center part thereof, and the thread substantially forms a geodesic curve, there is no risk that the thread will deviate from the wound thread. The rubber cap is securely pressed and fixed by the thread. The thread fixes the rubber cap at both ends of the long diameter and at the same time generates a force that presses the rubber cap toward the center of the ellipse, thereby reinforcing the oval tube in the long diameter direction. <Embodiment> In FIG. 1, 1 is an oval tube, 2 is a dish-shaped rubber cap fixed to the long diameter end of the tube 1, and 3 is a tube 1 connected to the tube 1 through the rubber cap 2.
It is a rotating shaft that supports the As shown in FIG. 2, a cotton cloth 4 is pasted on the inner surface of the rubber cap 2.
Glue is further applied to this and adhered to the end of the tube 1. The thread (first thread) 5 is wound around the rotating shaft 3 so as to press the rubber cap 2 toward the tube 1 side. Therefore, although there are portions where the thread does not exist at the abutting portions of the rotary shaft 3 at both ends of the tube 1, such portions are reinforced by the rubber cap 2. Figures 3 to 6 show the winding structure of the first to fourth threads, which threads are wound around the oval tube in the order shown. Figure A is a drawing viewed from the direction perpendicular to the major and minor axes of the ellipse, Figure B
is a drawing viewed from the direction that coincides with the major axis, and diagram C is,
5 is a diagram showing the magnitude of the reinforcing action in the major axis direction and the minor axis direction by the length of the arrow, corresponding to FIG. A. FIG. In the figure,
A point that differs every 90° on the plane including the short axis,
B, C, D, the front end (right end in the figure) of the long axis is O, the rear end (left end in the figure) is O', and the distance from the center of the ellipse to points O and O' is 10 equal points. Divide into regions a to j. As shown in Figure 3, the first thread starts from point A, moves toward point O at an appropriate angle of inclination, circles around point O, reaches two points 270° apart, and reaches point O. It goes around point ', and reaches point C, which is 270° apart from this, goes around point O, and reaches point B, which is separated by 270° from this, and then goes around point O', and reaches point C, which is 270° away from this. ° Return to the distant point A. This cycle is repeated a plurality of times with slight shifts, and the yarn is wound tightly around the i and j regions. Portions of the first thread near both ends of the tube cover the rubber cap 2 (FIG. 1). Next, as shown in FIG. 4, the second thread is spirally wound with a steep inclination angle close to the short diameter direction. The yarn is wound back and forth a plurality of times to make the areas a to f dense. Subsequently, as shown in Figure 5, the third thread starts from point A, moves towards point O with a steeper inclination angle than the first thread, and circles around point O by 360°. Then, return to the vicinity of point A, for example, a point slightly above point A, and then circle O' 360 degrees and return to the vicinity of point A, for example, a point slightly above point A. This cycle is repeated multiple times, and the third thread is wound densely mainly in the h and i regions. Furthermore, as shown in Fig. 6, the fourth thread starts from point A, moves toward point O at a steeper angle of inclination than the third thread, and circles around point O once. Reach point C, which is 180° apart from point A, and then move to point O' by 1
It circles around and returns to the vicinity of point A, which is 180 degrees away from point C, for example, a point slightly above this point. This cycle is repeated multiple times, and the fourth yarn is wound densely mainly in the g and h regions. As mentioned above, the first to fourth threads are wound around the tube surface in order, and once they have completed one cycle, this is repeated two to three times. The threads are made of nylon thread or the like, and about five threads at a time are coated with glue, arranged in parallel, and wound under slight tension. Thus, the thread passes substantially on the geodesic curve on the elliptical curved surface. The following table shows the relationship between the number of swings and angle of the tube and the number of rotations of the tube at each winding stage. The swinging drive of the tube is a swinging drive about the minor diameter direction as an axis, and the rotation of the tube is rotation about the long diameter as an axis, and the swinging drive and rotational drive are performed simultaneously. In addition, the number of swings in the table and the number of rotations are as follows.
It is shown by the ratio.

[Table] As shown in FIG. 3C, the first thread has a strong reinforcing effect in the major axis direction, and only a slight reinforcing effect in the minor axis direction. Also, this first thread is i,
In the j region, a tightening force that substantially coincides with the tangential direction of the ellipse is generated, and the tube internal pressure in this region can be suppressed efficiently. As shown in FIG. 4C, the second thread has a strong reinforcing effect in the minor axis direction, and only a slight reinforcing effect in the major axis direction. Further, this second thread generates a tightening force that substantially coincides with the tangential direction of the ellipse in regions a to f, and can efficiently suppress the tube internal pressure in this region. As shown in FIG. 5C, the third thread has a reinforcing effect in both the long axis direction and the short axis direction, and the reinforcing effect in the long axis direction is larger than the reinforcing effect in the short axis direction. Further, this third thread generates a tightening force that substantially coincides with the tangential direction of the ellipse in the h and i regions, and can efficiently suppress the tube internal pressure in this region. As shown in FIG. 6C, the fourth thread has a reinforcing effect in both the major axis and minor axis directions, and the reinforcing effect in the minor axis direction is greater than the reinforcing effect in the major axis direction. Further, this fourth thread generates a tightening force that substantially coincides with the tangential direction of the ellipse in regions g and h, and can efficiently suppress the tube internal pressure in this region. The first to fourth threads have a strong reinforcing effect in terms of one diameter, for example, the long diameter (the first thread);
Weak (2nd thread), Strong (3rd thread), Weak (4th thread)
They are wound alternately like this. Therefore, deformation during winding of the thread is suppressed to a minimum. On the thread-wound reinforcing layer formed as described above,
An oval ball is completed by gluing a rubber skin or by gluing a leather panel through a thin rubber layer. <Effects of the Invention> According to the present invention, since the rubber caps are fixed to both ends of the long axis of the elliptical tube, it is possible to reinforce the portions where there is no thread at both ends of the tube, which occurs when winding a thread. Furthermore, since the surface of the rubber cap has a thread wound around the center of the rubber cap in an area other than its center, and this thread essentially forms a geodesic curve, there is a risk that the thread may deviate from the originally wound thread. This is not the case, and the rubber cap is firmly fixed by pressing the thread.

[Brief explanation of the drawing]

Figure 1 is a front view of the main parts of one embodiment of the present invention;
The figure is a perspective view of the rubber cap, Figures 3A, B, and C.
FIGS. 6A to 6A, B, and C are diagrams for explaining the winding structures of the first to fourth threads. 1...Tube, 2...Rubber cap, 3...
Rotating shaft, 4...cotton cloth, 5...thread.

Claims (1)

[Scope of utility model registration request] It has an elliptical tube, a plate-shaped rubber cap placed on both ends of the long axis of the tube, a thread-wound reinforcing layer covering the tube, a skin layer made of a rubber or leather panel covering the thread-wound reinforcing layer, and a center of the rubber cap. In an elliptical ball formed by winding a part of the thread constituting the thread-wound reinforcing layer around the center of the rubber cap, the thread is wound in a circle including the minor axis of the ellipse.
If the points that differ every 90 degrees are A, B, C, and D, and the points at both ends of the long diameter that coincide with the center of the rubber cap are O and O', then starting from point A and passing through the surface of one rubber cap, , goes around point O, reaches two points 270° apart from point A, goes around point O′ through the surface of the other rubber cap, reaches point C, which is 270° apart from the two points, and It goes around point O through the surface of the rubber cap, reaches point B, which is 270 degrees apart from point C, and goes around point O' through the surface of the other rubber cap, and near point A, which is 270 degrees apart from point B. An oval ball, characterized in that it passes through a path returning to , and that the thread substantially forms a geodesic curve.