Sleeve system and fitting method

Abstract

Provided is a sleeve system for a golf-club, the system having high strength and not causing a loss in a striking sensation. A sleeve system S for a golf club 1 according to the present embodiment comprises: a head 2 in which a circular hole 22 is mortised along the central axis of a hosel 21, the head including a female screw groove 22a which is threaded only in a prescribed range on the opening side of the circular hole 22 and on the inner surface thereof; and a sleeve 3 into which an end of a shaft 4 is inserted so that the sleeve is attached to and secured by the shaft, the sleeve including: a grip 31 which is located nearest toward the base end side of the sleeve and which is gripped by a hand; a male screw groove 32 which is adjacent to the grip 31, which is threaded only in a prescribed range on the outer surface of the sleeve, and which screws together with the female screw groove 22a, and an abutment section 33 which is located nearest toward the tip end side of the sleeve and which abuts the inner surface of the circular hole 22.

Description

Sleeve system and fitting method

[0001] The present invention relates to a sleeve system for a golf club.

[0002] Conventionally, iron clubs are generally made by bonding the hosel portion of the iron head to the end face of the shaft with adhesive, so fitting shops have had to prepare the same number of shafts as the number of iron heads, even when different shafts are attached to the same iron head.

[0003] However, due to cost and storage space limitations, it has been difficult to prepare all combinations of iron heads and shafts in a fitting shop. Therefore, for example, Patent Document 1 describes a golf club in which the combination of shaft and head is interchangeable, and a double fastening device for the iron head and shaft is configured so that the lower and upper ends of a sleeve provided on the shaft are fixed to the iron head.

[0004] Japanese Patent Application Laid-Open No. 2021-94401

[0005] In a typical golf club, the upper part of the inner surface of the circular hole is glued, so there is no play in the upper part of the inner surface of the circular hole. However, in the conventional technology including the double fastening device described in Patent Document 1, the tip of the shaft is fixed to the bottom of the circular hole provided in the hosel, so there is play in the upper part of the inner surface of the circular hole. As a result, with the conventional technology, there are problems such as a decrease in the strength of the golf club and a loss of hitting feel.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sleeve system for a golf club that is strong and does not impair the feel when hitting the ball.

[0007] In order to achieve the above-mentioned object, the sleeve system for a golf club of the present invention is a sleeve system for a golf club, and comprises: a head having a circular hole drilled along the central axis of a hosel, the head having a female thread groove that is threaded only in a predetermined range on the inner surface of the circular hole on the entrance side; and a sleeve into which the tip of a shaft is inserted and adhesively fixed, the sleeve having a knob portion at the base end that is held by hand, a male thread groove that is threaded only in a predetermined range on the outer surface adjacent to the knob and screws into the female thread groove, and an abutment portion at the tip end that abuts against the inner surface of the circular hole.

[0008] Thus, the sleeve system for a golf club of the present invention comprises: a head having a circular hole drilled along the central axis of a hosel, the head having a female screw groove threaded only within a predetermined range on the inner surface of the circular hole near the entrance; and a sleeve into which the tip of a shaft is inserted and adhesively fixed, the sleeve having a knob located at the most proximal end to be held by hand, a male screw groove threaded only within a predetermined range on the outer surface adjacent to the knob and mating with the female screw groove, and an abutment located at the most distal end and abutting against the inner surface of the circular hole. Because this sleeve system has this configuration, it is possible to provide a golf club that is strong and does not impair the feel when hitting.

[0009] Fig. 1 is a perspective view illustrating the overall configuration of a golf club; Fig. 2 is a perspective view illustrating the configuration of a sleeve system; Fig. 3 is a cross-sectional view illustrating the operation of the sleeve system; Fig. 4 is an explanatory diagram illustrating the configuration of a sleeve, (a) being a side view and (b) being a plan view.

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the components described in the following examples are merely examples and are not intended to limit the technical scope of the present invention.

[0011] (Configuration) First, the overall configuration of a golf club 1 equipped with a sleeve system S of the present invention will be described using Fig. 1. As shown in Fig. 1, the golf club 1 of this embodiment is mainly composed of a head 2, a sleeve 3, and a shaft 4. Here, the golf club 1 equipped with the sleeve system S can be an iron or a utility club (rescue club).

[0012] As will be described in detail below, the golf club 1 of this embodiment is configured so that the shaft 4 is detachably (replaceably) attached to the head 2 via the sleeve 3. That is, the sleeve 3 is adhesively fixed near the lower end of the shaft 4, and the combination of the head 2 and the shaft 4 can be changed by threading the sleeve 3 onto the hosel 21 of the head 2.

[0013] 2, the head 2 is mainly composed of a main body 20 having a face surface 20a, and a cylindrical hosel 21 formed integrally with the main body 20 and attached to the shaft 4 (sleeve 3). The material of the head 2 is not limited, but is preferably soft iron or stainless steel, for example.

[0014] In this embodiment, a circular hole 22 is formed by drilling in the hosel 21 of the head 2. The drilling depth of the circular hole 22 to the bottom 22c is adjusted so that the weight of the shavings (cutting shavings; drilling shavings) is approximately equal to the weight of the sleeve 3. A female screw groove 22a that screws into the male screw groove 32 of the sleeve 3 is formed in the upper part of the inner surface of the circular hole 22.

[0015] More specifically, the interior of the circular hole 22 drilled in the hosel 21 is formed from a female screw groove 22a threaded at the top and a smooth abutment surface 22b without any irregularities located below the screw groove 23a and in contact (abutment) with the outer peripheral surface of the sleeve 3 without any gaps.

[0016] 2 and 3, the sleeve 3 is a cylindrical alloy part that is fixed to the tip of the shaft 4 with an adhesive. That is, the tip of the shaft 4 is inserted into the through hole 30 of the sleeve 3 and fixed with an adhesive. The shaft 4 is then fixed to the head 2 via the sleeve 3 in a replaceable manner.

[0017] Specifically, as shown in Figure 4, the sleeve 3 is a cylindrical sleeve 3 into which the tip of the shaft 4 is inserted and adhesively fixed, and its outer surface has a knob portion 31 located at the base end side to be gripped by hand, a male screw groove 32 adjacent to the knob portion 31 and threaded only over a predetermined range on the outer surface to screw into the female screw groove 22a, and an abutment portion 33 located at the tip end side and abutting against the inner surface (22b) of the circular hole 22.

[0018] The threads of the male screw groove 32 of the sleeve 3 and the female screw groove 22a of the head 2 are M11 pitch 0.75 mm left-handed (left-handed threads), so that when a right-handed batter (player) hits the ball, the screws tighten and are less likely to cause problems. Of course, they can also be made right-handed for left-handed batters.

[0019] The weight of the sleeve 3 of this embodiment has also been calculated. That is, there is no difference in weight between when this sleeve system S is used and when the hosel 21 and the shaft 4 are bonded together. In other words, the weight of the cutting waste generated during drilling is designed to be approximately the same as the weight of the sleeve 3.

[0020] While there are differences in the size of the diameter of the hole originally present in the hosel 21 and in the weight depending on the material, in the sleeve system S of this embodiment, errors are adjusted by the depth of the circular hole on the hosel 21 side.

[0021] Specifically, the weight of the sleeve 3 is designed to be approximately the same as the weight of the shavings produced during drilling. However, if the same drilling depth is used, there will be variations depending on the manufacturer and the head due to the size of the hole diameter and the density of the head material. Therefore, the drilling depth is adjusted to make it the same as the weight of the original head 2. Conversely, the weight of the sleeve 3 used uniformly for each manufacturer and each club is approximately the same as the average weight, or is slightly heavier. By adjusting the weight in this way, the sleeve system S can be used without any difference in feel, which is one of the major features of this sleeve system S.

[0022] Furthermore, it is common for other companies' sleeves (3) to have the fixing point at the tip of the sleeve, which can cause concerns about rigidity, but the sleeve system S of this embodiment has a screw groove 32 (22a) at the top, which makes it highly rigid and does not impair the feel of the hit.

[0023] The shaft 4 is a rod-shaped body that connects the head 2 and the grip, and is available in steel shafts made of metal (alloy) materials and carbon shafts made of carbon fiber. Generally, drivers are often fitted with carbon shafts, while other clubs often allow the choice of steel or carbon shafts. A sleeve 3 is glued and fixed to the lower end of the shaft 4.

[0024] (Method of Processing the Head) The head is processed by carrying out the following steps (1) to (4) in order.

[0025] (1) Preparation: Measurement / fixing to jig The hosel 21 of a typical head 2 has an uneven shape, low circularity, and is an ellipse with a difference in the length of the major axis and minor axis of about 0.3 mm, and is tapered in the vertical direction.Furthermore, there are individual differences even among heads made by the same manufacturer.

[0026] Therefore, in order to perform accurate cutting, since there are various hosel shapes available from various manufacturers, the hosel is measured and a fixing jig that matches it is selected.Then, the head 2 is fixed to the cutting machine (milling machine) via the fixing jig.

[0027] Then, based on the outer shape of the hosel 21, the center position of the shape is calculated using an accu-center (measuring device). The machining error from the center of the circle is precise, about 0.05 mm. Separately, a sleeve 3 prepared in advance is fixed to the tip of the shaft 4 with adhesive.

[0028] (2) Cutting Process The iron head 2 is relatively soft, containing a large amount of soft iron, and is therefore easily scratched during machining. Therefore, it is fixed to a fixing jig and machined accurately. To reduce cutting resistance, the hole machining is performed in two steps.

[0029] Specifically, a small diameter hole is drilled first, followed by a large diameter hole, as follows: First time: A φ10 mm end mill is used. Second time: A φ10.4 mm end mill is used. The drilling depth is approximately 29 mm. However, this drilling depth (hole depth) is adjusted so that the weight of the sleeve 3 and the weight of the shavings are the same.

[0030] (3) Thread machining: Machining is done precisely and coaxially. Since the drilled hole and the thread machining must be done concentrically, the head 2 is fixed in place, and a threading tool (M11 0.75 left tap) is attached to the milling machine, and a screw is cut to a depth of about 15 mm.

[0031] (4) Finishing: To facilitate smooth attachment and detachment, the φ10.4 hole is re-machined with a hand reamer to remove burrs that may have formed during threading. Finally, the appearance is checked and the process is complete.

[0032] (Attaching and Removing the Head and Shaft) The head 2 and shaft 4 are attached and removed by holding them by hand. That is, the sleeve 3 fixed near the lower end of the shaft 4 is screwed into the circular hole 22 provided in the hosel 21 of the head 2 by turning it counterclockwise, or removed by turning it clockwise.

[0033] This removal and attachment does not require any special tools, and the process itself is extremely smooth. In the rare case that the head 2 and sleeve 3 cannot be removed, the sleeve 3 can still be removed with a tool by utilizing the vertical groove in the knob 31 of the sleeve 3.

[0034] (Functions and Effects) Next, the functions and effects of the sleeve system S of this embodiment will be described.

[0035] (1) As described above, the sleeve system S for the golf club 1 of this embodiment includes: a head 2 having a circular hole 22 drilled along the central axis of a hosel 21, the head 2 having a female screw groove 22a threaded only within a predetermined range on the inner surface of the circular hole 22 near the entrance; and a sleeve 3 into which the tip of a shaft 4 is inserted and adhesively fixed, the sleeve 3 having a knob 31 located at the base end and gripped by hand, a male screw groove 32 adjacent to the knob 31 and threaded only within a predetermined range on the outer surface, which threads into the female screw groove 22a, and an abutment 33 located at the tip end and abutting against the inner surface of the circular hole 22. Because of this configuration, the sleeve system S can provide a golf club 1 that is strong and does not impair the feel of impact. This is because only the base (upper portion; the side closer to the grip) within the circular hole 22 is fixed to the sleeve 3 on the shaft 4 side.

[0036] In other words, by using the sleeve system S of this embodiment, the combination of the head 2 and the shaft 4 can be changed, thereby eliminating the storage space required for the head 2 and the shaft 4 at the fitting shop. Furthermore, by modifying a test club that the customer already owns, the test club can be utilized without being wasted. In addition, a golf club 1 can be provided that is stronger than conventional golf clubs and does not impair the feel when hitting the ball.

[0037] Other benefits include: - No change in weight: For example, if the sleeve 3 weighs 5g, the weight after machining is also 5g, so there is no change in weight. - Attachment and detachment by simply turning: No tools are required, so it can be easily attached and detached anywhere. - Future reduction in shaft costs: Shafts currently in use can be used with a variety of heads. This will broaden the range of fittings and enhance the range of test clubs. - Thorough cost management: The sleeve 3 is manufactured with cost as the top priority.

[0038] (2) It is preferable that the female screw groove 22a formed on the inner surface of the circular hole 22 of the head 2 and the male screw groove 32 formed on the outer surface of the sleeve 3 are left-handed threads that engage with each other. Therefore, even if a right-handed person hits a ball, the head 2 will not loosen from the sleeve 3.

[0039] (3) Furthermore, the drilling depth of the circular hole 22 is adjusted so that the weight of the shavings and the weight of the sleeve 3 are approximately the same, so the weight can be easily adjusted and there is no difference in the feel when using it.

[0040] (4) The fitting method of this embodiment is a fitting method that uses the sleeve system S described above, and includes the steps of adhesively fixing the sleeve 3 to the tip of the shaft 4, fixing the head 2 using a fixing jig, drilling a circular hole 22 in the head 2, using the fixing jig to thread the female screw groove 22a while the head 2 is fixed, and screwing the sleeve 3 and the head 2 together. Because this fitting method includes these steps, it is possible to provide a golf club 1 that is strong and does not impair the feel when hitting the ball. Furthermore, fitting can be performed using a golf club 1 that is strong and does not impair the feel when hitting the ball.

[0041] Among these, the process of drilling the circular hole includes a process of adjusting the drilling depth so that the weight of the shavings produced when drilling the circular hole and the weight of the sleeve 3 are approximately the same, so the weight can be easily adjusted and there is no difference in the feel when using it.

[0042] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes that do not deviate from the gist of the present invention are included in the present invention.

[0043] S Sleeve system 1 Golf club 2 Head 20 Main body 20a Face surface 21 Hosel 22 Circular hole 22a Female screw groove 22b Contact surface 22c Bottom 3 Sleeve 30 Through hole 31 Knob portion 32 Male screw groove 33 Contact portion 4 Shaft

Claims

1. In a sleeve system for a golf club; a head made of soft iron or stainless steel, having a circular hole drilled along a central axis determined based on the outer shape of the hosel, and having a female screw groove of a left-handed screw engraved only in a predetermined range on the inlet side of the inner surface of the circular hole; a cylindrical sleeve into which the tip of the shaft is inserted and adhesively fixed, having a grip portion that is located at the most proximal end and is gripped by hand, a male screw groove of a left-handed screw engraved only in a predetermined range on the outer surface adjacent to the grip portion and screwed into the female screw groove, and a contact portion that is located at the most distal end and contacts the inner surface of the circular hole, the sleeve being made of an alloy; and comprising: the female screw groove engraved on the inner surface of the circular hole of the head and the male screw groove engraved on the outer surface of the sleeve are left-handed screws that are screwed together. Sleeve system.

2. The sleeve system according to claim 1, wherein the drilling depth of the circular hole is adjusted so that the weight of the chips and the weight of the sleeve are substantially the same.

3. A fitting method using the sleeve system according to claim 2, comprising: a step of adhesively fixing the sleeve to the tip of the shaft; a step of fixing the head using a fixing jig; a step of drilling the circular hole in the head; a step of engraving the female screw groove while fixing the head using the fixing jig; and a step of screwing the sleeve and the head together. Fitting method.

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