JP3427514B2 - Racket string protector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a string protective material used in a tennis or a ball game racket similar thereto.

[0002]

2. Description of the Related Art As shown in FIGS. 8 and 9 , in a tennis racket 1, a string protective material 5 is attached to the outer peripheral surface of a racket frame 2 and a string (gut) 8 is stretched. The string protecting material 5 includes a tubular portion 7 and a band portion 6 connecting the tubular portions 7 to each other. This cylindrical portion 7
The racket frame 2 is inserted into the tubular portion insertion hole 4. The string 8 is inserted through the inner hole of the tubular portion 7.

By the way, in order to improve the impact absorbability of the string protector at the time of hitting a ball, a portion mainly in contact with the outer side of the frame is formed of a synthetic resin material or a rubber material having a tan δ of 0.01 to 1.0. The part that comes into contact with the gut has a static bending elastic modulus of 2000 to 15000 kg
A gut protective material for a racket, which is formed of a synthetic resin material having a thickness of 1 / cm ² , has been proposed (Japanese Patent Laid-Open No. 61-73675).
issue).

The portion that contacts the outer side portion of the frame and the portion that mainly contacts the string are integrally formed by a two-color injection molding method or integrated by adhesion (see the same publication No. 3). (Upper left column of the page).

As another string protection material having improved shock absorption, a material provided with a hollow portion has been proposed (actual flat plate 5).
-35161 gazette). In the string protective material of the same publication, the hollow portion is formed as a closed space portion having a closed chamber shape. Therefore, it is difficult to form the hollow portion of the string protecting material, and the manufacturing process is complicated.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a string protecting material that efficiently absorbs the shock applied to the string at the time of impact and makes it difficult to transmit the shock to the frame.

Another object of the present invention is to provide a string protective material which is easy to manufacture.

[0008]

SUMMARY OF THE INVENTION 請 Motomeko 1 racket string protection member includes a plurality of cylindrical portion string is inserted, the string protecting member racquet having a band portion for connecting the plurality of tubular portions In, at least a part of the band has a two-layer structure including a lower layer on the racket side and an upper layer on the side opposite to the racket, and the lower layer is softer than the upper layer.
Made of high quality material, in the band between adjacent cylinders,
A gap is formed between the upper layer and the lower layer so as to communicate with the side surface of the band portion.

According to a second aspect of the present invention, there is provided the string protecting material for a racket according to the first aspect , wherein the upper layer and the lower layer are laminated without being adhered to each other .

[0010] 請 Motomeko 3 racket string protection material, according to claim 1 or 2, viscoelastic member to the gap and is characterized in that it is filled.

In the present invention, the constituent material of the string protective material is a synthetic resin material or rubber having a tan δ of 0.01 to 1.0, especially 0.05 to 0.8, and particularly 0.05 to 0.2. preferable. Here, tan δ means the ratio between the loss elastic modulus (E ″) and the storage elastic modulus (E ′), that is, tan δ = E ″ / E ′. Here, the storage elastic modulus (E ′) is an elastic modulus in the same phase as the vibration stress, and is called a dynamic elastic modulus or simply an elastic modulus. On the other hand, the loss elastic modulus (E ″) is an elastic modulus advanced by 90 degrees from the vibration stress. Tan δ is called a loss tangent, and this tan δ is a measure of energy loss per cycle of the vibration stress. When a sine strain y = y ₀ · sin ωt is applied to the material test piece, the tan δ is measured by measuring the phase difference δ of the response stress with respect to this strain (deviation of the response to the applied vibration) and determining the tangent tan δ.

The constituent material of the upper layer of the string protective material is ta
It is preferable that nδ is less than 0.1. The constituent material of the lower layer preferably has a tan δ of 0.1 or more.

Specific constituent materials for the upper layer include amide resins such as 11 nylon and 6.6 nylon, olefin resins such as polypropylene and polyethylene, ABS and A.
Preferred are styrene resins such as ES, polycarbonate, ester resins such as polyethylene terephthalate, ether resins such as polyacetal, and the like.

Specific materials for the lower layer include urethane-based, ester-based, amide-based, styrene-based, olefin-based, and vinyl-based thermoplastic elastomers, or rubber materials such as high styrene-based SBR-based elastomers and polynorbornene-based elastomers. , Urethane rubber, butyl rubber and the like are suitable.

The viscoelastic member has a tan δ of 0.5 to.
It is preferably 1.0 and softer than the materials for the upper and lower layers described above.

Specifically, a member made of a known viscoelastic material such as silicone or α-gel can be used. In this case, a single member made of such a viscoelastic material can be used. When a gel or liquid having fluidity is used, it can be enclosed in an appropriate bag member and used as a viscoelastic member.

[0017]

[Action] In the string protecting member of 請 Motomeko 1, by providing a gap between the upper and lower layers, shock absorption has become good. The lower layer should be softer than the upper layer.
With, the entire lower layer acts like a cushion. Na
The upper layer is relatively hard, so it is large at impact.
It does not deform. Due to these, shock absorption
Improve significantly. Also, the resilience of the ball is sufficiently high.
Becomes

According to a second aspect of the present invention, the upper layer and the lower layer are simply laminated without adhering to each other, so that the interface between the upper layer and the lower layer when a shock is applied to the string protective material. A displacement (sliding, displacement) occurs along the line, which absorbs the impact and improves the impact absorption .

[0019] As 請 Motomeko 3, by filling the viscoelastic member in the gap, the shock absorbing property is improved.

[0020]

EXAMPLES Examples will be described below with reference to the drawings .

The perspective view of string protection member 24 according to the first embodiment of Figure 1 the present invention, FIG. 2 II of Figure 1 - sectional view taken along line II, Figure 3 is a second view FIG. 3 is an enlarged view around III .

This string protecting material 24 is a string
To connect a plurality of tubular parts 12 through which the
And a band portion 14A. The inner hole of the cylindrical portion 12 is the band portion 14
It penetrates so as to reach the upper surface of A. This obi 1
4A has a racket frame (not shown) on the lower surface side of FIG.
It is arranged so as to contact the outer peripheral surface, and the tubular portion 12 is a racket flap.
It is inserted into the cylindrical portion insertion hole of the ram. Inner hole of this cylindrical portion 12
A string 18 is inserted through 16.

In this embodiment, the band portion 14A has a two-layer structure having an upper layer 26 and a lower layer 28. The lower layer 28 is made of a softer material than the upper layer 26. The upper layer 26 and the lower layer 28 are simply laminated without being bonded.

In this embodiment, the gap 30 is formed by forming a concave portion on the lower surface side of the upper layer 26. The gap 30 extends from one side surface of the band portion 14A to the other side surface. The gap 30 has a substantially half-cylindrical shape.

[0025] While this upper surface of the upper layer 26 is flat, as the upper layer 26A of string protection member 32 shown in FIG. 4, may be formed similar crests 20A and the string protection member 10.

[0026] The string protection member 2, which is configured as this
In Nos. 4 and 32, since the gap 30 is provided, the impact of the string at the time of impact is absorbed, and the impact is less likely to be transmitted to the racket frame.

In this embodiment, the belt portion 14A is the upper layer 2
Since the lower layer 28 is softer than the upper layer 26, the lower layer 28 acts as a cushion as a whole, and the shock is efficiently absorbed. In addition, in this embodiment, the upper layers 26, 26
Since A and the lower layer 28 are simply superposed and in a non-adhesive state, displacement (slip) in the interface direction at the contact interface between the upper layers 26, 26A and the lower layer 28 when a shock is applied to the strip portion 14A. Occurs and the shock is absorbed.

[0028] In other words, as shown in FIG. 3, a string 18
Is in contact with the corner edge 33 on the upper surface side of the inner hole 16, and the impact applied to the string 18 at the time of impact is the corner edge 3
Was added to 3, the force for displacing the upper 26 to the right in Figure 3 occurs. By this force, the upper layers 26, 26A and the lower layer 2
At the interface 8 (especially the interface in the vicinity of the inner hole 16), displacement in the interface direction occurs, and the shock is efficiently absorbed.

Since the upper layers 26, 26A are relatively hard, the corner edges 33 of the upper layers 26, 26A do not deform so much at the time of impact. Therefore, good resilience can be obtained.

[0030] In the embodiment of the first to Figure 4, upper layer 26
Or it forms a gap 30 by providing a recess 26A, as in the string protection member 34 shown in FIG. 5, it may be provided a gap 30 by forming a recess in the lower layer 28. Additionally, string protecting member 36 shown in FIG. 6
As described above, the gap 30 may be formed by forming a recess in both the upper layer and the lower layer 28.

FIG. 7 is a cross-sectional view of an essential part of a string protecting material 38 according to still another embodiment of the present invention. The string protecting member 38 is obtained by filling a viscoelastic member 40 in the gap 30 in the string protecting member 32 shown in the Figure 4. Other configurations are the same as Figure 4. By thus filling the gap with the viscoelastic member 40, the shock can be more efficiently absorbed.

It should be noted, may be filled with viscoelastic member between gap even string protecting member other than the Figure 4. Such a viscoelastic member may be integrally formed by a two-color molding method or the like when forming the upper layer or the lower layer, or may be formed by filling the concave portion after forming the upper layer or the lower layer. The viscoelastic member 40 may be adhered to the upper layer or the lower layer,
It may be simply superposed.

[0033] The present invention odor Te between gap size is formed to hole, gap geometry, its formation location differs depending on the material, etc. of the band portion, generally, with respect to the tangential direction of the height direction (frame outer peripheral surface It is preferably 1 to 4 mm, more preferably 1.5 to 3 mm (in the vertical direction).

[0034] In the present invention, _(t 2, _{t 3} for example of FIG. 11) of the thickness and the upper of the upper thickness of the gap 30 of the upper first 0 band portion of the through hole 22 shown in FIG., 1 mm or more Especially 1
It is preferably ˜2 mm.

[0035]

As described above, the string protective member according to the first to third aspects can efficiently absorb the impact at the time of impact, and the impact is less likely to be transmitted to the frame. Further, the string protective material of the present invention is extremely easy to manufacture.

The string protecting material according to the second aspect can absorb the impact at the time of impact more efficiently by utilizing the displacement between the upper layer and the lower layer. In the string protecting material according to the first to third aspects, good resilience can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a string protection member 24 according to an embodiment.

It is a sectional view taken along the line II - [2] of II FIG.

3 is an enlarged cross-sectional view of the vicinity of III of Figure 2.

FIG. 4 is a cross-sectional view of a string protection member 32 according to an example.

FIG. 5 is a cross-sectional view of a string protection member 34 according to an example.

FIG. 6 is a cross-sectional view of a string protection member 36 according to an example.

FIG. 7 is a cross-sectional view of a string protective material 38 according to an example.

FIG. 8 is a perspective view showing a conventional string protective material.

FIG. 9 is a cross-sectional view of a main part of a racket equipped with a conventional string protective material.

FIG. 10 is a cross-sectional view showing dimensions of a string protective material according to an example.

[Explanation of symbols]Two 4,32,36,38 String protector 12 Tube1 4A obi 16 bore 18 StringGu Two 6,26A Upper layer 28 Lower 30 gap 40 Viscoelastic member

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-1-166780 (JP, A) JP-A-61-73675 (JP, A) Actual flat 5-35161 (JP, U) Actual flat 5- 58163 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) A63B 51/10

Claims (3)

(57) [Claims] 1. A plurality of cylindrical portions through which a string is inserted,
A racket strike with a belt portion connecting the plurality of cylinders
In ring protection material, At least a part of the strip is a racket-side lower layer and a racket.
It has a two-layer structure consisting of the ket and the upper layer on the opposite side.
,The lower layer is made of a softer material than the upper layer, Between the upper layer and the lower layer in the band portion between the adjacent tubular portions.
In addition, make sure that there is a gap leading to the side surface of the band.
Character string racket protective material. 2. The racket string protecting material according to claim 1 , wherein the upper layer and the lower layer are stacked without being adhered to each other. 3. The string protective material according to claim 1 , wherein the gap is filled with a viscoelastic member.