Note: Descriptions are shown in the official language in which they were submitted.
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This invention telates to the manufacture of hockey sticks.
The traditional material for hockey sticks is wood, and
the sticks are made by glueing a wooden blade to a wooden handle.
The joint is spliced and carefully made so that usually the joint
is not the first area to fail if the stick is subjected to abuse.
However~ wood is expensive, and a good deal of
production quality control is needed if the joint is to be
consistently reliable. Also, wood splinters when it breaks. Many
injuries have been caused by the splintered ends of broken
sticks.
PRIOR ART
Attempts have been made therefore to provide hockey
sticks in plastic materials. In Canadian patent No, 873,488
(issued 15 June 1971 to FRANCK) a stick handle is made by winding
fibres over a mandrel and setting those fibres in resin, which is
left to cure.
In U.S.A. patent No. 4,086,115 (issued 15 April 1978 to
SWEET) a stick handle is made by an extrusion or drawing process,
termed pulltrusion~ This is a generally continuous process for
making hollow sections in glass fibre reinforced plastic.
The manner of attaching blades to handles has been the
subject of a number of previous proposals, and besides the above
the following patents are typical of those that contain relevant
teachings:
U.S. 3,961,790 - 8 June 1976, MILLIGAN
3,934,875 - 27 January 1976, EASTON
27 4,369,970 - 25 January 1983, SALMINEN
4,358,113 - 9 November 1982, McKINNON
All of these previous proposals have involved
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compromise. It is the aim of the invention to provide a manner of
manufacturing hockey sticks in fibre-reinforced plastic material
in which all the important aspects of performance can be
maximized together, without undue expense.
BRIF D~SCRIPTION OF THE INVENTION
In the invention, the handle is moulded in elongate
moulds. A channel as long as the handle is formed in one mould
and the resin-impregnated fibres (in mat form) are laid over or
in the channel. A core presses the mat into the channel, along
the full length of the channel. (The term "mat" is used in this
specification should not be construed as referring only to the
kind of mat commonly called "chopped strand mat'1 in fibre plastic
technology. The term generically includes chopped strand mat,
woven-roving mat, and other styles in which the filaments or
fibres are arranged in mat form.)
As will be described later, the handle can either be
made as two U shaped sections which are glued together, or the
handle can be made as a single section wrapped around a mandrel~
which is later removed after the resin has cured. In either
case, the benefits of the core-within-a-channel manner of
moulding the handle has these benefitsO
1) The section of the handle can be varied. The main
length of the handle can be the traditional rectangular section
that is favoured by players, while the lower end of the handle
can be shaped to the most advantageous and strongest profile to
receive the blade. This ability for the section to be changed
27 according to the requirements of the different regions of the
handle may be contrasted with the very limiting restrictions of a
handle formed b~ an extrusion process.
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2) The fibres may be laid in the proportions for khe
best performance balance. The ratio of the fibres laid lengthwise
to those laid hoop-wise can be adjusted, not only handle-to-
handle, but at different locations on the one handle. The wall
thickness of the handle also may be easily adjusted for the best
results.
3) The oustide surface of the handle is smooth. This
surface is derived from that of the mould; virtually no finishing
is needed, other than trimming at the mould parting-line. Good
dimensional repeatability is achieved. The external corners may
be of small-radius (as they are in wooden handles).
4) The handle is hollow, and the walls may be relatively
thin yet strong, so that the handle itself is light.
5) The manner of making the sticks is simple yet also
efficient, as will be described below. Very little hand work is
; required,
In an embodiment of the invention, the operation of
making the handle and of attaching the handle to the blade are
carried out simultaneously. This is extremely economical and
provides a very strong hockey stick.
The blade of the stick may be made itself of fibre-
reinforced plastic, or it may be of wood, or may be a plastic
injection-moulding~
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Figures 1 and 2 are cross-sections of press moulds at
different stages of closure;
27 Figure 3 is a cross-section of a hockey stick handle;
Figure 4 is a view o~ a hockey stick during
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construction;
Figures 5 and 6 correspond to Figures 1 and 2 but show
other press-moulds;
Figure 7 is a plan of a mould during manufacture of a
hockey stick;
Figure ~ is a cross section on line A-A of Figure 7.
Figure 1 shows a pair of complementary moulds for use in
a press. A channel-shaped lower die 11 and a core 12 are mounted
respectively in the relatively movable parts of the press, When
the press closes, the core 12 enters the channel 13 of the
channel-shaped die 11. The channel 13 extends in an elongate
manner at right angles to the plane of the figure.
In Figure 2, the press has closed, and the core has
entered the channel to such a degree as will leave a clearance 10
between the core and the channel.
A length of resin-impregnated matting 14 of glass fibres
is placed over the die 11, and becomes trapped between the core
12 and the channel 13 when the press is closed, The core 12 may
be clamped to the die 11, and the core and die then removed from
the press while the resin cures, or the moulds may be left in
place in the press while the resin cures.
When the resin is cured, the core 12 is removed from the
channel 13, either by simply lifting the core out, or by sliding
the core lengthwise along the channel. The cured resin mat is
then removed from the channel.
The elongate piece 15 of cured resin, reinforced with
27 the glass fibres, is U-shaped in cross-section. The piece 15
will form part of the handle of the hockey stick. Another such
~-shaped piece 16 is prepared in the same manner, except that the
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overall width of the section of one piece 15 is dimensioned to
fit tightly between the arms of the U of the other piece 16.
The two pieces 15,16 are glued together along their
length so as to form a hollow rectangular tube, which will be the
handle 17 of the hockey stick, as shown in Figure 3.
The U section of the pieces 15,16 is uniform throughout
most of the length of the handle. Towards the bottom of the
handle 17 the pieces are tapered: the handle becomes less in
thickness in that it tapers down to the slimness of the blade 1~
of the stick, but the handle 17 also increases as to its vertical
height in that the height tapers out to that of the blade 19.
This aspect may be seen in Figure 4.
The hollow interior of the handle 17 is open at the very
bottom of the handle, and comprises a slot 21. The blade 19 is
provided with a spigot 22, which is shaped to fit the slot 21.
The spigot 22 is glued into the slot 21 to attach the blade to
the handle. The transition between the handle section and the
blade section of the handle is done at the bend 20 of the stick.
As may be seen in Figure 4, the angle at which the blade spigot
enters the slot is substantially inclined to the length of the
handle, which provides a good strong joint.
Figures 5 to 8 show another manner of manufacturing
hockey sticks. Again, the lower die 23 of the press is channel
shaped. The core 24 is not now mounted for movement with the
press, but takes the form of a mandrel which is adapted to lie in
the channel 25. A plunger 26 moves downwards into the channel
27 when the press closes, and the arrangement is such that a
clearance is left all round the core 24.
To make a handle, a piece of matting 27 is wrapped
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around the core 24, the ~dges being overlapped on top of the
core, The wrapped core is then squeezed in the press.
The bottom end of the core 24 is located in the channel
25 in the manner shown in Figures 7 and ~0 With the press open,
the blade 29 of the stick is fitted tightly into a slot 30 in the
die 23. The fit is such that the blade 2g is firmly held in the
die 23, and such that resin in the channel 25 is contained
against leakage between the sides of the slot 30 and the sides of
the blade 29. The core 24 fits onto a spigot 31 of the blade 29,
so that the core is held in place by the blade.
Wrapping the core 24 in the mat 27 is done so as to
leave a portion of the mat extending beyond khe core. This
portion then enwraps the blade 29.
Such a joint is very strong. Yet it was formed at the
same time as the handle was made. The savings in production
costs are substantial. The mat covers and extends over the whole
joint area, providing a robust, rigid bridge between the handle
and the blade.
When the resin has cured, the core or mandrel 24 can be
~0 removed from the inside of the handle: the core of course was
coated with release agent prior to being wrapped 9 and also the
core has a slight draft angle to ease removalO
The mat used to make the handle may be chopped strand
mat, or it may be woven-roving mat. Preferably, however, the mat
is made by arranging the fibres in a manner especially applicable
to the invention.
27 The fibres are provided as a continuous roving, a roving
being a loosely packed (not twisted) bundle of filaments some 3
mm wide and around 0~2 mm thick~ ~he roving is cut into lengths
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as long as the handle, and the lengths are laid beside each
other, ei~her in the channel, or on a sheet of plastic draped
over the channel. This is done with the roving in a dry state.
The lengths are packed tightly together to form a dense mat. The
mat may be just one roving thick, or it may be two or more
rovings thick.
Resin is poured over the mat, and the mat pressed in the
press as described above. The degree of compression is set so
that the resin penetrates into all spaces and interstices and
thoroughly wets the fibres, as known per se in the art.
Arranging the roving in this manner is suitable when the
lengths of roving are disposed along the length of the stick or
at a slight angle thereto. The roving may be arranged in a hoop
disposition by winding the roving around khe mandrel. Again, one
mat may be formed in this manner, or several hoop-shaped mats may
be formed, one ~ver the other.
When plural thicknesses of roving are provided 9 the
fibres may be of different materials, to achieve a desired
balance of strength and economy. The fibres may be for example
all of glass, or they may all be carbon fibres. Or, the mat may
be arranged in layers of alternating materials. Pigment may be
added to the resin, as desired.
Not only does the invention provide a very strong yet
economical stick, it allows the stick to be of the familiar
rectangular shape. The corner radius of the rectangle can be as
sharp as the radius on the corresponding wooden handle. The
27 sharpness of the corner is limited by the tendency of a sharp
corner to be easily chipped in use, not by any restrictions
imposed by the method of manufacture.
