U.S. patent application number 10/673418 was filed with the patent office on 2005-03-31 for weight member for a golf club head.
Invention is credited to Chen, Chan-Tung, Huang, Chun-Yung.
Application Number | 20050070371 10/673418 |
Document ID | / |
Family ID | 34376605 |
Filed Date | 2005-03-31 |
United States Patent
Application |
20050070371 |
Kind Code |
A1 |
Chen, Chan-Tung ; et
al. |
March 31, 2005 |
Weight member for a golf club head
Abstract
A weight member for a golf club head is made of a WMoNi alloy by
powder metallurgy or a precision casting process. The WMoNi alloy
includes tungsten 1-70 wt %, molybdenum 4-55 wt %, and nickel 25-95
wt %. Molybdenum increases the density of the weight member and
improves the rust-resisting property of the weight member. The
tungsten, molybdenum, and nickel provide a uniform metallographic
phase. Uniformity of shining finishing of the weight member is thus
improved.
Inventors: |
Chen, Chan-Tung; (Kaohsiung,
TW) ; Huang, Chun-Yung; (Kaohsiung Hsien,
TW) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
34376605 |
Appl. No.: |
10/673418 |
Filed: |
September 30, 2003 |
Current U.S.
Class: |
473/338 ;
473/349 |
Current CPC
Class: |
A63B 2209/00 20130101;
A63B 53/0433 20200801; A63B 53/06 20130101; A63B 53/047 20130101;
A63B 53/04 20130101; A63B 60/00 20151001 |
Class at
Publication: |
473/338 ;
473/349 |
International
Class: |
A63B 053/04; A63B
053/06 |
Claims
1. A weight member for a golf club head, the weight member being
made by a WMoNi alloy in a precision casting process, the WMoNi
alloy comprising a composition of molybdenum 4-55 wt %, nickel
25-95 wt %, and tungsten 1-70 wt %, wherein said weight member
comprises of a WMoNi-alloy casting, and the composition of said
molybdenum, nickel and tungsten provide a uniform metallographic
phase that prevents a surface of the WMoNi-alloy casting from
precipitation of tungsten in the precision casting process.
2-3. (Cancelled)
4. The weight member for a golf club head as claimed in claim 1,
wherein the WFeNi alloy has a density of 8.6 g/cm.sup.3-16.6
g/cm.sup.3.
5. The weight member for a golf club head as claimed in claim 1,
further comprising silicon of less than 1.5% to increase
flowability during casting.
6. The weight member for a golf club head as claimed in claim 1,
comprising at least one component for improving a mechanical
property of the weight member.
7. The weight member for a golf club head as claimed in claim 6,
wherein said at least one component includes manganese of less than
1.0%, copper of less than 4.0%, vanadium of less than 1.0%, and
niobium of less than 1.0%.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a weight member. In
particular, the present invention relates to a weight member for a
golf club head.
[0003] 2. Description of Related Art
[0004] A conventional weight member for a golf club head is made by
powder metallurgy in which metal powders of high density and high
rigidity such as tungsten having a density of 19.30 g/cm.sup.3,
iron having a density of 7.8 g/cm.sup.3, and nickel having a
density of 8.9 g/cm.sup.3 are pressed and formed and then sintered
to form a WFeNi alloy that forms the weight member for a golf club
head. Although the powder metallurgy is widely used, several
disadvantages exist, including high cost for molds, low
stretchability of products, long processing time, aptness to
thermal expansion/shrinkage, and difficulty in forming delicate
patterns, letters, serial number, trade names, etc.
[0005] Another method for manufacturing a weight member made of
WFeNi alloy includes a precision casting process in which a
specific metal melting sequence and a specific composition ratio
are utilized to prevent sedimentation of tungsten having a high
melting point. In the precision casting process, nickel of 30%-50%,
iron of 30%-50%, tungsten of 20%-35%, silicon of less than 1%,
manganese of less than 1%, and niobium of less than 0.5% are fed
into a high-temperature furnace at a temperature above 1450.degree.
C. and melt to form a weight member made of WFeNi alloy for a golf
club head. The weight member is then inserted or welded to a golf
club head body that is generally made of stainless steel of SUS304,
17-4, and 4130.
[0006] This precision casting process overcomes the problems of the
above conventional powder metallurgy. However, if the mixture ratio
of the nickel, iron, and tungsten was not properly controlled, a
pearlite structure was precipitated in a base of a .gamma. (iron,
nickel) phase of the WFeNi alloy, deteriorating the rust-resisting
property of the weight member. Further, cracks were apt to be
generated while welding the weight member to the golf club head
body. During spray testing at 40.degree. C. for 24 hours (which
simulates a highly corrosive environment) to the WFeNi alloy by
using NaCl solution of 5% by weight, the rusted area of the WFeNi
alloy often exceeded 8% of the overall surface area of the WFeNi
alloy. Further, since tungsten was often precipitated on the
surface of the WFeNi alloy (the deep color portion is the pearlite
structure and the white portion surrounded by the pearlite
structure is the precipitated tungsten), the tungsten/.gamma.
(iron, nickel) phase formed by the alloy caused patterns on the
weight member made of WFeNi alloy after grinding and polishing
procedures. As a result, an obvious insertion line was generated
when the weight member made of WFeNi alloy was directly inserted
into a bottom surface of a golf club head body. Further, the
insertion line of the products varied in response to the thickness
ground off and the grinding angle. Thus, it is difficult to control
the processing conditions.
[0007] In conclusion, since the conventional weight member made of
WFeNi alloy contains iron such that the weight member has poor
characteristics in the metallographical composition, rust-resisting
property, and welding. The assembling procedure, appearance,
bonding strength, manufacturing tolerance, and life of the golf
club product are adversely affected.
OBJECTS OF THE INVENTION
[0008] An object of the present invention is to provide a weight
member for a golf club head, wherein molybdenum is added to
increase the density of the weight member and to improve the
rust-resisting property of the weight member.
[0009] Another object of the present invention is to provide a
weight member for a golf club head, wherein the weight member is
made of a WMoNi alloy to improve the uniformity of the shining
finishing and the appearance of the weight member.
SUMMARY OF THE INVENTION
[0010] To achieve the aforementioned objects, the present invention
provides a weight member for a golf club head that is made of a
WMoNi alloy by powder metallurgy or a precision casting process.
The WMoNi alloy includes tungsten 1-70 wt %, molybdenum 4-55 wt %,
and nickel 25-95 wt %. Molybdenum increases the density pf the
weight member and improves the rust-resisting property of the
weight member. The tungsten, molybdenum, and nickel provide a
uniform metallographic phase. Uniformity of shining finishing of
the weight member is thus improved.
[0011] Other objects, advantages and novel features of this
invention will become more apparent from the following detailed
description when taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0012] FIG. 1 is an exploded perspective view of a golf club head
in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] A preferred embodiment of the present invention is now to be
described hereinafter in detail.
[0014] A golf club head in accordance with the present invention
includes a golf club head body 20 having a recession 21 and a
weight member 10 engaged in the recession 21 of the golf club head
body 20 by means of welding, insertion, pressing, or brazing. The
shape of the weight member 10 and the location of the recession 21
can be altered according to the product need. The weight member can
be made by powder metallurgy.
[0015] In a case that the weight member is manufactured by a
precision casting process, metals are fed into a high-temperature
furnace at a temperature between 1450.degree. C. and 1750.degree.
C. (preferably 1660.degree. C.-1680.degree. C.) in a specific metal
melting sequence and a specific composition ratio while controlling
the mixture ratio among tungsten, molybdenum, and nickel, thereby
forming a molten WMoNi alloy. Next, the molten WMoNi alloy is
poured into a preheated mold with a specific shape, precise
patterns, and letters. The preheating temperature for the mold is
set between 950.degree. C. and 1300.degree. C. Thus, a weight
member for a golf club head is made by a precision casting process.
The weight member is then engaged (by, e.g., insertion, welding,
pressing, etc.) to a golf club head body that is generally made of
stainless steel, such as stainless steel of SUS304, 17-4, and
4130.
[0016] According to the present invention, in the precision casting
process, nickel particles, molybdenum particles, and tungsten
particles are added in sequence into the high-temperature furnace.
The molten nickel reduces the melting point of the tungsten. Thus,
the tungsten particles having a high melting point melt in the
furnace without causing sedimentation of tungsten. Next,
appropriate sampling test and control are proceeded to form molten
WMoNi alloy comprising tungsten 1-70 wt %, molybdenum of 4-55 wt %,
and nickel of 25-95 wt %. Although the density of molybdenum (10.2
g/cm.sup.3) is smaller than that of tungsten (19.3 g/cm.sup.3)
having a melting point at 3410.degree. C., molybdenum has a lower
melting point (2610.degree. C.) so that, the furnace temperature
required for precision processing is lowered through increasing the
amount of molybdenum and reducing the amount of tungsten.
[0017] The density of the WMoNi alloy can be changed according to
different uses of the golf clubs. Preferably, the density of the
WMoNi alloy is between 8.6 g/cm.sup.3 and 16.6 g/cm.sup.3.
[0018] In a case that the weight member is manufactured by power
metallurgy, tungsten powders of 1-70 wt %, molybdenum powders of
4-55 wt %, and nickel powders of 25-95 wt % are mixed and then
pressed and sintered to form the required weight member 10.
[0019] In either case, the weight member made of WMoNi alloy
contains no iron, and the amount of tungsten in the WMoNi alloy is
lower than that in conventional weight members made of WFeNi alloy.
Since the WMoNi alloy contains no iron and since the density of
molybdenum is greater than iron, the rust-resisting property of
molybdenum is better than that of iron. As a result, the weight
member 10 would not generate pearlite structure that adversely
affects the strength or rust-resisting property. Namely, the weight
member in accordance with the present invention has a greater
density and improved rust-resisting property. During spray testing
at 40.degree. C. for 24 hours (which simulates a highly corrosive
environment) to the WMoNi alloy by using NaCl solution of 5% by
weight, it was found that the rusting problem was improved by the
WMoNi alloy.
[0020] In addition to insertion, pressing, and brazing, the weight
member 10 can be engaged to the golf club head body 20 by welding
such as tungsten inert gas arc welding, laser welding, or
electrical arc welding.
[0021] Further, since the tungsten, molybdenum, and nickel provide
a uniform metallographic phase, no y (iron, nickel) phase is
generated. Thus, precipitation of tungsten on the surface of the
WMoNi alloy is prevented, and undesired patterns would not be
generated. Since the surface of the weight member 10 provides
improved shining finishing uniformity, the insertion line between
the weight member 10 and the golf club head body 20 can hardly be
seen when the weight member is directly engaged to (particularly by
insertion) the surface of the golf club head body 20 and then
polished. Thus, the engaging difference between individual golf
club head body 20 and the weight member 10 can be avoided, and the
processing conditions can be controlled to be the same.
Accordingly, the added value and the engaging/assembling tolerance
of the weight member 10 are increased.
[0022] Further, the flowability during casting can be improved by
means of adding silicon less than 1.5%. Further, an appropriate
amount of manganese (Mn), copper (Cu), vanadium (V), and niobium
(Nb) can be optionally added. The mechanical properties of the
weight member, the flowability during casting, and removal of gas
are improved when at least one of Mn of less than 1.0%, Cu of less
than 4.0%, V of less than 1.0%, and Nb of less than 1.0% is added.
Further, the WFeNi alloy may contain trace elements such as carbon
of less than 0.1%, sulfur of less than 0.1%, and phosphorus of less
than 0.1%.
[0023] According to the above, the disadvantages of the weight
member made by the conventional precision casting process are
obviated and/or mitigated by the weight member 10 in accordance
with the present invention. The physical/chemical properties of the
weight member 10 are improved by means of replacing iron with
molybdenum. The density of the weight member 10 is increased.
Further, the rust-resisting property, uniformity of the shining
finishing, appearance, and the assembling tolerance of the weight
member are improved while allowing the weight member to be welded
to a golf club head body.
[0024] While the principles of this invention have been disclosed
in connection with its specific embodiment, it should be understood
by those skilled in the art that these descriptions are not
intended to limit the scope of the invention, and that any
modification and variation without departing the spirit of the
invention is intended to be covered by the scope of this invention
defined only by the appended claims.
* * * * *