JP3045407U - Iron golf club head - Google Patents

Abstract

(57) [Summary] (With correction) [PROBLEMS] To provide an iron head having a cavity which is opened rearward and is surrounded by a peripheral portion. A head includes a main body of a low-density metal material and an additional insertion member having a higher density. The peripheral portion has a lower portion extending vertically below the cavity and extending horizontally from the toe to the heel, the insert occupying a portion thereof, and the concave upper central portion and the heel. And a raised toe at the toe, generally crescent-shaped. In one example, the head body includes a housing disposed within the sole and continuous from the toe to the heel, and the insert is retained in the housing and clamped between the striking surface and the periphery. In another example, the housing is defined from the wall of the striking surface and the edge of the cavity to the sole and from the back center edge extending a portion of the length of the head. It is crescent shaped with a central notch that opens to the side and reduces the thickness of the sides.

Description

[Detailed description of the invention]

The present invention relates to the field of golf, and more particularly to an iron golf club head.

[0002] Various types of iron golf clubs are commercially available. Among these golf clubs, a club having a head shape such as a metallic blade is generally called a “blade”. These clubs focus on skilled and professional players who value the quality of impact at impact, despite the lack of tolerance for blades during off-center strokes (off-center strokes). It is targeted. None of these heads achieve a high inertia value Iy (measured about a vertical axis through the center of gravity). In particular, the measured value for a 5 iron is very close to or less than 220 kg / mm ² . Such low values result in insufficient tolerance and reduced accuracy, and the ball will deflect with respect to the intended trajectory, especially if impact occurs in the area off the center of the striking surface.

[0003] Widely used heads are generally made of steel and have a rear cavity to allow mass to be distributed around the useful portion of the striking surface, commonly called the "sweet spot" There are different types of clubs that have been. These clubs are known as "cavity back irons." Most players at any skill level play with this club because of its versatility and tolerance for off-center strokes. In view of the peripheral distribution of mass, the inertia value Iy is larger than that of the blade type head, and is about 220 to 240 kg / mm ² for the No. 5 iron. However, in this category of clubs, the center of gravity is generally high relative to the ball and generally above the theoretical strike point, which results in a rough feel when hitting and is not appreciated by players. In particular, the vertical height of the center of gravity relative to the ground varies from about 0.75 to 0.85 inches.

Finally, there are various other types of iron heads, such as clubs where the head is made of a non-ferrous metal material such as titanium. These commercially available iron heads have a low density of titanium, and can make the head larger even if the total mass is equal to the total mass of the steel head, so that the fifth iron is about 240 to 250 kg / mm ^2. Reaches a considerable inertia value Iy. However, the center of gravity of these clubs is very high, about 0.9 inches, resulting in poor feel, low backspin rates, and poor control.

[0005] Some heads have two structural parts made of metals of different densities. Generally, this structure is based on a striking surface made of a lightweight metal such as aluminum or titanium, and a main body made of a heavy material such as steel. Therefore, significant inertia values Iy were measured in the range of 270-330 Kg / mm ² because the mass located in the impact area was distributed around the periphery of the club head. The performance of this type of club is adversely affected if the center of gravity is not properly positioned in both the vertical and horizontal directions (ie, it has a known adverse effect on impact feel and backspin rate in the vertical direction, and horizontal In the direction, the ball tends to slice due to the gear effect acting on the ball.)

US Pat. No. 5,429,353 relates to a set of cavity back iron clubs wherein the depth of the perimeter surrounding the cavity varies with respect to the end of the cavity, the surface of the cavity is flat, and Being parallel to the surface, the location of the center of gravity coincides with the geometric center of each head. This geometric center is considered to be substantially a point along the sole at a distance equal to the radius of the golf ball measured from the center point. This corresponds to a distance of about 0.8-0.9 inch (about 2.0-2.3 cm) from the center point of the sole.

US Pat. No. 5,094,457 relates to a golf club in which the center of gravity is moved in the axial direction of the shaft and the rotational inertia about the axis of the shaft is reduced by approaching the sole of the head. Its purpose is to facilitate rapid rotation about the axis Is of the shaft prior to impact so that the impact plane is perpendicular to the plane of the swing. If Is = Iy + md ² (where d is the distance of the center of gravity to the axis of the shaft), the prior art solution is, inter alia, to reduce the dominant factor (i.e. Is to minimize it. This causes the center of gravity to be 1.35 inches (or 3.429 cm) from the axis of the shaft, too close to the axis of the shaft, and the center of gravity is shifted from the center of impact toward the heel. This results in reduced performance (ie, ball rebound or reduced initial velocity when hitting the center of impact).

Further, US Pat. No. 5,094,457 does not mention anything about the need to maximize inertia about a vertical axis through the center of gravity. In addition, a large Iy value is unlikely to be achieved because the Is value is being reduced as much as possible.

As shown in FIGS. 9B and 10A to 10C of this prior patent, the iron head is a blade type (that is, a rear cavity capable of obtaining a sufficient inertia Iy about an axis). Has no). More specifically, the head has a blade-shaped upper portion having a substantially constant thickness, which is connected to a thicker lower portion where the mass is concentrated.

[0010] Such a structure has the same general disadvantages as those reported for bladed irons.

In view of the current state of the art and the above-mentioned drawbacks, the present invention provides an enlarged club head that optimizes the distribution of mass on an iron head (more specifically, to solve the drawbacks of the prior art. By adjusting the position of the center of gravity, and maintaining a moment of inertia centered on the Iy value sufficient to stabilize the club at impact, even in the case of off-center stroke (off-center stroke) To provide an enlarged club head that optimizes volume distribution.

[0012] The present invention results in a significant increase since the center of gravity is located below the geometric center of the surface.

To this end, the present invention provides a heel area, a toe area, a striking surface extending between the toe area and the heel area, and a sole that rests on the ground when the head is in the address position. And a back surface, the back surface having a cavity that opens rearward and is surrounded by a peripheral edge. A preferred club has a heel section with an opening for II 'located in the heel section to introduce the shaft. The center of gravity of the head is preferably below a horizontal plane about 18.3 mm (about 0.72 inches) above the sole plane. Further, preferred club heads have an inertia of 230 kg / mm ² or more about a vertical axis through the center of gravity of the upper body. In a preferred structure, the club head includes a body made of titanium or a titanium alloy and at least one additional mass having a density higher than the density of the body. The perimeter also includes, beneath the cavity, a lower portion extending from the heel section to the toe section, and the additional mass (es) becomes at least a portion of the lower section.

By selecting a body of low density material, such as titanium or a titanium alloy, and an additional mass that is precisely positioned with a higher density, the basic parameters (ie, the location of the center of gravity and Inertia) can be adjusted to avoid disadvantages of the prior art.

According to another feature of the invention, the center of gravity is located at a distance of 35 mm to 40 mm from axis I-I '. This keeps the center of gravity not too far from the heel. If the center of gravity is too far from the heel, the initial velocity of the ball may decrease. Also, the shift in the center of gravity of the toe must not be too large to avoid the ball effect skewing to the right due to the gear effect.

According to another feature of the invention, the additional mass occupies 25 to 70% of the total mass of the head, the remainder being occupied by a body made of titanium or a titanium alloy. As a result, the additional mass occupies a significant portion of the mass allocated in the head, thereby achieving the properties required for inertia and center of gravity.

As a non-limiting example, the other features and advantages of the present invention will be appreciated by reading the following description with reference to the accompanying drawings, which show how the present invention may be embodied. You can understand better.

FIG. 1 shows the iron head 1 of the present invention including a striking surface (ie, a front surface) 2 which is laterally edged with a toe area 3 and an opposing heel area 4. The sole 5 is located below the striking surface 2 and at address the head rests on the ground via this sole.

The heel section 4 extends upwardly through the hosel 6, the cross section of the hosel being an opening having the axis I-I '. This opening 60 serves to receive the end of the shaft (not shown).

The center of gravity is represented by the point 7 shown on the surface, but in reality this center of gravity is located on the horizontal line passing through the point 7 behind the surface.

According to the present invention, the center of gravity 7 is located immediately below the plane P representing a limit of 18.3 mm (about 0.72 inches) with respect to the sole plane P ′. Emphasis must be placed on obtaining a sufficient feel comparable to the feel of a bladed iron at impact and a relatively high backspin speed that improves ball control. By construction, it is preferred that at least 55% of the total mass of the head is distributed directly below the plane P.

Conventionally, the sole plane P 'is a reference plane (ie, the ground surface) determined when the ball is in an address state. Plane P is parallel to P 'and lies 18.3 mm (about 0.72 inches) above plane P'.

The horizontal position of the center of gravity is also important and must be accurately located. If the center of gravity is too close to toe area 3, the ball will deflect to the right. This is due to the gear effect. When the ball hits the center of the surface, the surface attempts to rotate counterclockwise about axis I-I ', while the ball rotates in the opposite direction, moving the ball to the right. Similarly, it is not desirable for the center of gravity to be too close to axis I-I '. This is because the head tends to rotate (clockwise), and thus retreats during a shot, so that the impact force is reduced.

Accordingly, the center of gravity is advantageously located at a vertical distance d of 35 mm to 40 mm (preferably 35 mm or 38 mm) from axis I-I '.

As usual, the vertical distance d is the distance measured between the axis II ′ and a plane passing through the center of gravity and parallel to the axis II ′ and perpendicular to the front face. .

It is also important to determine the position of the center of gravity behind the striking surface 2, such a position affecting the trajectory of the ball. The center of gravity 7 is preferably located at a distance of more than 3 mm from the hitting surface. Therefore, the distance separating the center of gravity from the surface 2 is measured by a line passing through the center of gravity and parallel to the sole surface. Unlike the prior art, which places the center of gravity as close as possible to the surface, here it is necessary to raise the ball and maintain sufficient dynamic loft needed to avoid the problem of lateral trajectory dispersion. The emphasis on certain biases is encouraged.

It should be noted that the position of the center of gravity varies according to the loft angle within a set of iron clubs according to the present invention. In particular, it is recognized that the position of the center of gravity gradually decreases as the loft angle increases.

FIG. 2 shows the rear surface 8 of the head which opens rearward and has a central cavity 80 surrounded by a peripheral edge 81. The perimeter includes a lower portion 810 that extends horizontally from the heel section 4 to the toe section 3 and extends vertically from the cavity 80 to the sole 5. The lower portion is continuously connected to an upper portion 820 defined vertically by an upper edge 821 connecting the open cavity and the surface.

FIGS. 2 to 6 show that the head is composed of a plurality of individual parts. The head includes a main body 90 constituting a major part of the volume of the head, and an additional mass body 91 having a smaller volume.

The main body is made of a metal material having a low density (that is, 7 g / cm ³ or less), but having high mechanical properties. A preferred material is titanium or a titanium alloy having a density close to 4.5 g / cm ³ . For example, a Ti-6A1-4V type alloy having an elastic resistance of about 120,000 psi, or a Ti-3A1-2. 5V type alloys can be mentioned.

Other low-density metallic materials, such as aluminum or aluminum alloys or aluminum matrix composites reinforced with boron carbide (density 2.7 g / cm ³ ), can also be used.

The additional mass body 91 is selected from high density material (i.e., high density material at least 10 g / cm ^3, rather preferably is 12~20g / cm ^3).

This material is tungsten (having a density close to 18) or a mixture of tungsten and copper known under the trade name “SPARKAL” (having a density close to 15).

[0034] An insert made of sintered metal produced from a mixture of metal powders having various densities, producing an insert having a predetermined density corresponding to the proportion of material present in the mixture. Is preferred. The use of masses of sintered metals based on tungsten alloys is described in particular in US Pat. No. 3,955,820 (COCHRAN). Known methods for producing sintered products based on tungsten, copper, steel or other metal materials include the step of mixing metal powders having various densities. Then, in a second step, the mixture is pressed in a mold having the general shape of the mass to be produced, but having a volume approximately 20% greater than the final volume of the mass to be produced. This pressing operation is continued until a compressed mixture, commonly called "green compact", is obtained. The size of the mold is determined by simple similar enlargement. Therefore, they agglomerate, but remain brittle.

The next step involves a sintering operation and consists in heating the compressed mixture formed in the previous step to about 2,000 ° F. without pressure in a furnace. The volume of the mixture is reduced by about 20% compared to the initial volume after compression. The porosity disappears under the influence of temperature, and the mixture becomes stronger and denser. Finally, a conventional sandblasting operation is performed. The final product obtained amounts to about 100% of the theoretical density based on the weight of the material mixture contained in the product. In other words, for example, from two types of materials having initial masses of M1 and M2 and densities of d1 and d2, respectively, the density (that is, theoretical density) dT of a sintered mixture is obtained by using the following equation. And can be easily calculated. dT = d1 ・ [M1 / (M1 + M2)] + d2 ［[M2 / (M1 + M2)]

The desired final volume Vf of the additional mass is obtained by the following equation: Vf = (M1 + M2) / dT Of course, the above two equations can be easily generalized for the material of n.

According to a currently known preferred embodiment of the additional mass, the desired density dT is about 12. This density is obtained from a mixture of 50% by weight of tungsten, 50% by weight of copper or bronze and traces of nickel and / or tin and / or beryllium (to improve corrosion resistance).

According to the present invention, the additional mass must occupy 25 to 70% of the total mass of the head (preferably, 30 to 50% of the total mass). For example, for a head having a total mass of 225 g, the additional mass occupies about 100 g (ie, 44.5% of the total mass). It should be noted that the total mass of this head is the average value of commercially available heads. This additional mass is not intended to increase the mass of the head, but to achieve various characteristics such as adjustment of the inertia Iy and the position of the center of gravity by redistributing the mass under different conditions.

In commercial heads known to date, the added mass only accounts for 15 to 20% of the total mass, which is insufficient to achieve the desired properties.

In the first embodiment shown in FIGS. 1 to 6, the additional mass 91 comprises a single mounting member having a variable cross section, extending from the heel section 4 to the toe section 3, and having a peripheral edge. The lower part 810 of 81 is integrally formed. In this way, the mass forms the rear surface 810a of the lower portion of the periphery. In this configuration, the portion 800 connects the end of the cavity 80 to the upper edge 810b which borders the rear surface 810a, and the portion 50 of the sole 5 extends from the lower edge 810c of the rear surface 810a to the striking surface 2. Extend.

More specifically, the cross section of the mass gradually increases from the middle section 811 to each of the heel section 4 and the toe section 3. In this way, the mass distribution of the toe / sole / heel is improved, and a very high inertia value can be achieved while lowering the center of gravity. In this case, the substantially curved shape of the lower portion 800 of the cavity provides the additional mass 91 with various shapes. The portion having a series of radii of curvature R1, R2 and R3 has at least one radius of curvature R1 in the middle section, which is smaller than the radii of curvature R2 and R3 of the end sections at the heel and toe of the section. .

FIGS. 4-6 also illustrate that the mass 91 has a shape that extends downward (ie, toward the sole 5) to further facilitate lowering of the center of gravity.

Due to the structure of the embodiment shown in FIGS. A center of gravity located at a distance of 680 inches (1.676 to 1.727 cm) and a moment of inertia Iy of typically 240 to 255 kg / mm ² are obtained.

The moment of inertia Iy is measured along an axis yy ′ passing through the center of gravity 7 and perpendicular to the ground P ′.

FIG. 7 shows a second embodiment in which the additional mass body 91 forms only a part of the lower portion 810 of the peripheral portion. More specifically, this additional mass is attached to the rear surface 810a and the lower edge 810c of the lower portion 810, which extends downward to a lower edge 810c (ie, a falling edge). Forming a portion of the sole 50 extending therethrough. In this case, the mass does not form part of the cavity part 800. This structure allows the center of gravity to be lowered a little further (i.e., 0.640-0.680 inches). The change in the moment of inertia is 235 to 250 kg / mm ² .

In another embodiment, shown in FIG. 8, the mass forms an upper portion of a rear surface 810a of portion 810, which portion 810 extends to an upper edge 810b and from which a cavity is formed. A portion 800 that extends to the end of 80 is formed. In this case, the lower, or falling, edge 810c is made of titanium or a titanium alloy, which also provides better resistance to sole wear. Conversely, the location of the center of gravity is located slightly above (i.e., 0.675 to 0.700 inches). The moment of inertia is also low, about 230 to 245 kg / mm ² .

Finally, in the embodiment shown in FIG. 9, the head comprises two laterally separated masses 910, 911, the center of one of which is near the heel area 4 and the other The center of the mass is near toe area 3.

In another embodiment (not shown) similar to the previous embodiment, the head extends from the heel area to the toe area and is provided by the thin edges of the body from both the cavity and the sole. It could include a single mass that is insulated. That is, masses 910 and 911 join to form a single mass.

FIGS. 10 to 17 show a preferred embodiment of the present invention.

The head is composed of a main body 90 made of a low-density metal material (preferably a titanium alloy) and a high-density head forming a weight at the lower part of the head so that the position of the center of gravity is lowered below the horizontal plane as defined above. And a mounting insertion member 91 made of the above. More specifically, the insertion member 91 forms a part of the lower portion 810 of the peripheral portion 81 surrounding the central cavity 80. The inserts respectively form:-a rear surface 810a of a portion 810 bounded by a concave upper ridge 810b and a lower ridge 810c;-extending in the direction of the surface 2 from the lower ridge 810c. And at least a portion 50 of the sole 5; and at least a portion of the depth of the concave lower portion 800 connecting the bottom of the cavity 80 to the upper ridge 810b.

Therefore, this position of the insert member does not adversely affect the overall shape of the head maintaining the cavity-back type structure, which is primarily to increase the sweet spot on the striking surface, without affecting the center of gravity of the head. Helps position as low as possible.

The insert preferably includes a central upper portion 800 a that forms only a portion of portion 800, but does not extend to the bottom of cavity 90, such that the insert is a part of body 90. It is located on an edge 800b and forms excess thickness relative to the surface. This excess thickness is necessary to allow sufficient penetration of the screw inside the body.

According to a second feature of the present invention, the lower ridge 810c of the lower portion 810 of the insert includes a central chamfered area 810d. This chamfered area reduces the frictional resistance of the rear part of the sole, and also allows hard objects such as stones (sintered materials to be more commonly used than materials produced by other techniques such as forging, casting, etc.). The risk of impact of the ridge on the ridge is also reduced. The chamfered area may extend more or less substantially toward the toe and heel ends. However, in order to maintain maximum inertial properties, it is preferable not to unduly affect the mass at these ends.

As mentioned above, the insert is preferably made of sintered metal manufactured using powder technology. It has been found that such inserts have reduced yield strength, especially when high density materials such as tungsten are used, preferably in the ratios described above. In particular, the insert does not exhibit very high durability when the insert is subjected to tensile stresses that occur upon deformation of the head due to impact. As a result, the insert may break beyond a certain yield point.

Therefore, the selection of the method of connecting the insertion member to the main body is most important, and the selection of the method affects the durability of the head at impact. In particular, the connection method is selected so that a compressive stress is applied to the insertion member. This pre-stress (pre-stress) makes it possible to reduce the deformation of the material below the yield strength when the material is stressed at the time of impact.

As shown in FIGS. 10, 13, 13a and 14, the insert is secured on the body by two laterally spaced screws 700,710. A first screw 700 with a shoulder 700 a is located near the heel area 4. A second screw 710, also comprising a shoulder 710 a, is located near the toe area 3, at a distance from the first screw 700.

As shown in more detail in FIG. 13a, each screw engages along the first portion through the inner bore 917 of the insert, having a diameter sufficient to slide the threaded portion. The second portion (ie, the end opposite the shoulder of the screw) has a thread that meshes within the body by screwing. Of course, as shown here, the entire shaft portion may be threaded. Therefore, the shoulder 710a is supported on the edge of the inner hole of the main body, and exerts a force on the insertion member to press the insertion member onto the main body. Preferably, the angle of inclination of shoulder 710a should be greater than 20 degrees with respect to the longitudinal axis of the screw to apply sufficient force to the insert to prestress. On the other hand, to limit the lateral dimension of the shoulder, this angle of inclination should not exceed 40 degrees.

Each screw is tightened by a head projecting beyond the surface of the peripheral edge, but this head is not shown. After assembly, the head is ground or polished.

The cross section of the insertion member varies along its entire length in order to obtain the maximum inertia value about the axis y-y ′. In particular, the cross section of the insert increases from the center of the mass towards the heel area 4 and the toe area 3 respectively. This increase is progressive and is preferably made in a generally concave shape in the central portion 800a of the insert.

FIGS. 15-17 show in detail the specific shape of the insert to obtain the desired physical properties. The insert is generally crescent shaped and the concave upper central portion 800a becomes part of the head portion 800 when the insert is attached to the body. The concave shape of this area lowers the center of gravity as well as helps maintain the upper cavity necessary to maximize the sweet spot area. The insert also has raised lateral portions 913, 914 surrounding both sides of the central portion 800a and located respectively in the heel and toe areas of the head. In order to obtain the desired inertia value, the raised portion 913 located in the toe area generally has a larger cross section than the raised portion 914 located in the heel area. The insertion member has through holes 917, 918 for passing screws connecting the side surfaces 915, 916 (shown in FIGS. 12 to 14). The sides 915, 916 extend in the direction of the sole portion 50 in order to always assist in lowering the center of gravity. The inner surface 915 is preferably a flat, adjusted surface to facilitate housing the insert in the body housing.

FIGS. 18 to 22 show a second structural embodiment according to the present invention.

The main body includes a housing 70 provided only on the sole 5 and extending continuously from the toe area 3 to the heel area 4, and a single insert member having a shape complementary to the shape of the housing 70. 91 is accepted. The insert occupies only the central part of the width of the sole 5 and is connected on both sides to the front sole edge 51 connected to the striking surface 2 and to the lower part 810 of the peripheral edge 81 of the body. It is bordered by the rear sole edge 52. The insert 91 is generally crescent shaped and has a concave inner center to easily achieve a low center of gravity position and a heel / toe distribution that provides a large inertia about the axis yy ′. Section 912 and raised lateral sections 913, 914 in the heel and toe areas, respectively. The insert has a generally inverted V-shaped cross-section, as shown in FIGS. 20 and 21, and its sides 915, 916 also have a sole as described above in order to maximize the center of gravity of the head. It spreads in the direction of.

Such an assembly, in which the insert 91 is sandwiched between the striking surface 2 and the rear edge 81 of the rear surface 8, has a number of advantages, the first of which is that the assembly at impact. The upright structure can be deformed uniformly, which increases the connection strength between the main body and the insertion member. In fact, since the modulus of elasticity of the material forming the body is much lower than the modulus of elasticity of the insert, if the insert is simply attached after the body, as in the previous example, the body will be more rigid than the insert. Try to deform. In the sandwich structure of this embodiment, the deformation occurs more uniformly without danger to the connection between the two members.

The joining of the main body and the additional mass body is achieved by press-fitting the insertion member into the housing 70 of the main body.

The insertion member is securely fixed by a pin passing through the main body 90 and the insertion member 91, preferably two pins 700 and 710 arranged at a distance. The insertion member has through holes 917 and 918 connecting the side surfaces 915 and 916. In the embodiment of FIG. 18, the wall of the striking surface 2 is provided with holes that match the positions of the through holes 917, 918 after the insertion member has been assembled. Therefore, each pin 700, 710 is mounted by a press fit through the hole, securely securing the insert in the housing.

In this particular embodiment, it is preferable to attach the pins from the side of the striking surface, since the finishing operation is easier. The striking surface, which must be perfectly flat, is ground and polished at the pins by a suitable finishing tool, for example a belt wheel. However, it is also conceivable to attach the pins from the opposite side (ie from the rear edge 81 of the rear surface of the body).

Of course, the insert may be secured within the housing by other techniques, such as by gluing with an epoxy-type adhesive. Similarly, screws can be used instead of pins.

FIGS. 23 and 24 show another embodiment which is similar to the embodiment of FIGS. In this case, the body 90 is transversely partitioned on the one hand by the wall of the striking surface and on the other hand by the rear central edge 811 which extends from the edge of the cavity 80 to the sole and only a part of the length of the head. Housing 71 included. That is, the edge 811 does not extend from the toe to the heel, but remains localized in the central portion of the head.

In the toe area 3 and the heel area 4, the housing 71 is open both rearwardly and to the sole. Therefore, the insert 91 occupies the space created by the housing thus defined, and the central notch 920 defines a locally reduced thickness of the side in this area, and The central edge 811 of the main body is arranged at the end of the main body, and has a crescent shape as a whole. In this way, the insert is clamped only in the central portion of the head (ie, the area where deformation at impact is greatest), making the deformation of the assembled structure formed by the body and the insert more uniform. The insertion member 91 is pressed onto the holes 917, 918 therethrough and secured on the body by pins 700, 710 inserted into holes provided in the striking surface. The connection can also be made by using an adhesive instead of the pin.

This structure facilitates heel / toe mass distribution, thereby increasing inertia about the axis yy ′, while maintaining uniform deformation at impact and connection between the mass and body. There is an advantage of securing good strength.

FIGS. 25-28 show another advantageous embodiment of the present invention. In this case, the insertion member is attached to the rear part of the head main body as in the embodiment of FIGS. 1 to 6, for example.

The rear surface 8 of the body includes a lower recessed area 72 having a bottom surface 720 and a narrow edge 721 that preferably has an acute angle to the bottom surface 720. The bottom surface 720 extends substantially parallel to the striking surface 2 or at a slight angle.

The insertion member 91 is generally crescent shaped and has a concave inner portion 912 and raised ends 913, 914. The insert includes a flat inner surface 915a and side edges 915b that form an acute angle with the surface 915a. The insert is also secured to the recessed area 72 by a dovetail connection. This connection is formed on the one hand by protruding tenons (or projections) 722, 723 secured to the bottom surface 720 and on the other hand on the inner surface 915 of the mass adapted to contact the bottom surface 720. Mortise holes 921, 922. In the illustrated embodiment, two mortises are provided, one near the toe and one near the heel. The mortises are arranged parallel to each other and have openings facing the engagement side of the connection (ie the side of the concave portion 912).

The insertion member 91 and the tenons 722, 723 have holes which match during assembly and are perpendicular to the direction in which the tenon and the tenon engage to secure the insertion member. Or through a fixing member such as pins 700, 710 oriented substantially vertically. Of course, especially for the reasons explained above, screws can be used instead of pins if the insert is made of sintered powder.

It should also be noted that the insert member 91 has the advantageous feature of having a thickness distribution that facilitates proper distribution of mass in the heel and toe areas of the head. For example, the thickness e of the insertion member 91 is thinner in the center than in the toe area 3 and the heel area 4. More specifically, the thickness gradually increases from the center toward the raised portions 913, 914.

FIGS. 25 and 28 show an embodiment in which the insertion member 91 is engaged in the recessed area 72 of the main body 90. This mode of engagement proceeds in the direction of the sole, generally towards the upper ridge 821 of the head (arrow A), until the edge 915b of the mass abuts against the edge 721 of the recessed area 72. Will be It should be understood that the securing member constituted by the pins 700, 710 must be oriented in a direction transverse to the direction of engagement.

FIG. 29 to FIG. 31 show a mere modification of the above embodiment. In this embodiment, the connection between the insertion member and the head can be performed in a direction (arrow B) from the heel area 4 to the toe area 3. The only difference from the previous embodiment lies in the orientation of the dovetail connection and fixing members. In this case, the mortise / pawls 722, 723 cooperate with a single mortise 923 extending along the entire length of the inner surface 919a of the insert. After assembly, the insert can be secured by pins 701, 711 oriented transverse to the direction of the mortise 923.

As in the previous embodiments, the pin can be securely fixed with an adhesive or a screw instead of the pin.

The additional mass body can be attached and fixed to the main body by various techniques such as co-molding, soldering, squeezing, and bonding.

Although the preferred embodiment of the present invention has been described in detail above, those skilled in the art may consider various modifications without departing from the scope of the present invention defined in the claims for utility model registration. it can.

FIG. 32 shows an embodiment of the present invention. The rear surface includes a lower recessed area 72 having a bottom surface 720 and a narrow edge 721 as previously described. In addition, elongated ribs 724 extending in a toe / heel direction along substantially the entire bottom surface accurately fit into complementary shaped grooves 924 extending along a substantial portion of the length of the inner surface of the insert. Combine. In this way, the insert is secured mainly by a press fit in the recessed area. The ribs also have the effect of reinforcing the thin lower part of the adhesive surface and also reduce the stress that tends to separate the body from the insert during impact. As in the previous embodiment, pins or screws can be added to further enhance this assembly.

[Brief description of the drawings]

FIG. 1 is a front view of the head of the present invention.

FIG. 2 is a rear view of the head of FIG. 1;

FIG. 3 is a side view of the toe of the head of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 2;

FIG. 5 is a sectional view taken along the line VV of FIG. 2;

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 2;

FIG. 7 is a rear view of a head according to a modification of the present invention;

7a is a sectional view taken along line VII-VII of FIG. 7;

FIG. 8 is a view similar to FIG. 7, according to another variant.

FIG. 8A is a sectional view taken along line VIII-VIII in FIG. 8;

FIG. 9 is a view similar to FIG. 7, according to a further variant.

FIG. 10 is a rear view of the head according to the preferred embodiment of the present invention.

FIG. 11 is a rear perspective view of the head of FIG. 10;

12 is a sectional view taken along line XII-XII in FIG.

13 is a sectional view taken along line XIII-XIII in FIG.

FIG. 13a is a detailed sectional view of FIG. 13;

FIG. 14 is a sectional view taken along line XIV-XIV in FIG. 10;

FIG. 15 is an outer bottom view showing the additional mass body of the head of FIG. 10;

FIG. 16 is an inner side view showing the additional mass body of the head of FIG. 10;

FIG. 17 is a bottom perspective view showing the additional mass body of the head of FIG. 10;

FIG. 18 is an exploded perspective view showing a specific assembly of a head according to a specific embodiment of the present invention.

FIG. 19 is a rear view of FIG. 18;

20 is a sectional view taken along line XX-XX in FIG.

FIG. 21 is a sectional view taken along line XXI-XXI in FIG. 19;

FIG. 22 is a bottom view of the head of FIG. 19;

FIG. 23 is a rear exploded perspective view showing a specific assembly of a head according to another embodiment of the present invention.

FIG. 24 is a perspective view of the head of FIG. 23 after assembly.

FIG. 25 is a rear exploded perspective view showing a specific assembly of the head according to another embodiment of the present invention.

FIG. 26 is a sectional view of the head of FIG. 25;

FIG. 27 is a view of the inside of an additional mass attached to configure the head of FIG. 25;

FIG. 28 is a rear perspective view of the head of FIG. 25 showing an assembling operation.

FIG. 29 is an exploded rear perspective view showing a specific assembly of a head according to a modification of the head of FIG. 25;

FIG. 30 is a diagram showing an assembling operation of the head of FIG. 29;

FIG. 31 is an inner side view showing an additional mass body attached to configure the head of FIG. 29;

FIG. 32 is an exploded rear perspective view of the head according to another embodiment of the present invention;

FIG. 33 is a sectional view taken along line XXXIII-XXXIII of FIG. 32, showing a specific assembly of the head according to the embodiment of FIG. 32;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Iron club head 2 Hitting surface 3 Toe area 4 Heel area 5 Sole 7 Center of gravity 8 Rear surface 60 Opening 70 Housing 80 Central concave part (cavity) 81 Peripheral part 90 Head main body 91 Additional mass body 700, 710 Screw 700a, 710a (Screw ) Shoulder 810 lower part 810a rear surface 820 upper part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Brett Waal United States. 92008 Lafayette Court, Carlsbad, California 2397 (72) Inventor Steve Nutens United States. 92083 California, Vista, Paseo del Lago 1833

Claims (10)

[Utility model registration claims] 1. A heel area, a toe area, a striking surface extending between the heel area and the toe area, a sole resting on a ground plane when placed on the ground for a hit ball, and a rear surface. An iron golf club head, wherein the rear surface includes a cavity that opens rearward and is surrounded by a peripheral portion. An additional insert made of a material of high density, the perimeter including a lower portion extending vertically below the cavity and extending horizontally from the toe area to the heel area; The insert member generally occupies at least a portion of the lower portion and has a generally concave upper central portion and a raised side portion in each of the heel and toe sections. An iron golf club head having a sun-moon shape. 2. The insert member is made of metal and a rear surface of a lower portion defined by the following portions, that is, a concave upper ridge portion and a lower ridge portion; At least a portion of the sole extending from the portion toward the surface;
By forming at least a portion of a concave lower portion connecting the bottom of the cavity to the upper ridge,
2. The iron golf club head according to claim 1, wherein the iron golf club head forms a part of a lower portion of the peripheral portion. 3. The iron golf club head according to claim 1, wherein the insert member is made of a sintered metal material and is connected by a connecting member that exerts a compressive stress on the insert member. 4. The method according to claim 1, wherein the insert is provided with one shouldered screw located near the toe area, and near the heel area.
Fixed with another screw with a shoulder located at a distance from the one screw, each screw having a diameter sufficient for the sliding member to have a diameter sufficient to allow sliding engagement. 4. The iron golf club head according to claim 3, wherein the head engages the body along a second portion that engages along a first portion and enables a screwed engagement. 5. The iron golf club head according to claim 3, wherein the sintered metal material forming the insert member is a mixture of various metal powders having different densities. 6. A heel area, a toe area, a striking surface extending between the heel area and the toe area, a sole resting on a ground plane when placed on the ground for a hit ball, and a rear surface. An iron golf club head, wherein the rear surface includes a cavity that opens rearward and is surrounded by a peripheral portion, the iron golf club head having a body made of a low-density metal material and having a density higher than the density of the body. At least one insert, wherein the body comprises a housing disposed within the sole and extending continuously from the toe area to the heel area, the insert occupying the housing, and An iron golf club head sandwiched between the hitting surface and the peripheral portion. 7. The iron golf club head according to claim 6, wherein said insert has a generally crescent-shaped shape having a concave inner central portion and raised portions in the toe and heel areas. . 8. A heel area, a toe area, a striking surface extending between the heel area and the toe area, a sole resting on a ground plane when placed on the ground for a hit ball, and a rear surface. An iron golf club head, wherein the rear surface includes a cavity that opens rearwardly and is surrounded by a peripheral edge, wherein the heel area includes an axis located within the heel area for introducing a shaft. An opening having II '; the head having a center of gravity lying below a horizontal plane parallel to the ground plane, and having a height relative to the ground plane of 18.3 mm;
Also, the head has a vertical axis y- passing through the center of gravity of the upper part of the main body.
The head has an inertia of 230 kg / mm ² or more around y ′; furthermore, the head comprises a body made of titanium or a titanium alloy and at least one additional mass having a higher density than the body. Said perimeter includes a lower portion extending from said heel section to said toe section below said cavity, at least a portion of said lower section comprising said additional mass. Iron golf club head. 9. The iron golf club head according to claim 8, wherein 55% of the total mass is located below the horizontal plane. 10. The iron golf club head according to claim 8, wherein the center of gravity is located at a vertical distance of 35 mm or more and 40 mm or less from the axis II ′.