Note: Descriptions are shown in the official language in which they were submitted.
-- ` 2038820
--1--
TOOL HANDLE AND METHOD OF ATTACHING
A HANDLE TO A PERCUSSIVE TOOL HEAD
BACKGROUND OF THE lNV~NllON
This invention relates generally to hand
tools. More particularly, the present invention
relates to an improved composite handle and means for
attaching the handle to the heads of percussive tools,
such as hammers, hatchets, axes and the like, in such a
manner that the union will be strong and invariable
during the normal useful life of the tool, and which
may be utilized equally well during the original
manufacture of the the tool or while replacing the
handle in the field.
Until recent years the only material used for
handles in percussive tools, i.e., striking, cutting
and/or prying tools such as hammers, sledges, peaveys,
axes, etc., has been wood. For this reason, the method
of attaching the handle to the tool head, whatever type
it might have been, was dictated by the property
characteristics of wood. It is generally recognized
that, other than being strong enough to withstand
handle abuse the tool would regularly take, there are
two conditions which must be accommodated when
inserting a wood handle into a tool head: to keep the
tool head attached to the handle under all working
conditions; and to maintain the head tight to the
handle.
Traditionally, in percussive tools such as
sledge hammers, the tool head includes an aperture or
eyehole through its body which has a single or double
taper. In both cases, the taper expands at the top of
the tool head or that portion which is normally
directed away from the user when the tool is in use.
When a wooden handle is driven through the eyehole from
the bottom side of the tool head, the excess wood
protruding from the top side is cut off, and some
3~,
- 20~8820
-2-
wedging device, such as an ordinary wedge, is driven
into the wood so that the upper end thereof is expanded
to provide an inverted frustum which, theoretically, is
tightly expanded into the tool eyehole. The expanded
section of wood must fit within the upper tapered
portion of the eyehole tightly so that the head cannot
fly off during use. This is a very elemental assembly
which has been in use for many years.
The use of wedges and the like to expand the
upper section of the wood within the eyehole inherently
involves damage to the handle which adversely affects
many of the physical properties which are desired to be
retained. Further, the wedges that are driven into the
end of the wooden handle often tend to work loose, due
most frequently to changes in humidity which cause
alternate swelling and contraction of the wood with a
gradual decrease in tightness. Many expedients have
been employed in an attempt to overcome these faults,
including the provision of metal sleeves to hold the
tool handle in place, the use of adjustable wedges
which must be periodically driven by the owner of the
tool to compensate for loosening of the joint, the use
of metal handles, the casting of wedges in position in
the tool, and the provision of rubber sleeves
interposed between the handle and the head. None of
these aforementioned expedients have proven to be
entirely satisfactory.
The primary reason why prior handles are
typically inserted from the bottom and wedged at the
top of the tool head is that there are very few tools
which have an eyehole large enough to provide an
opening through which the grip of the handle can pass.
In prior handles, if the handle were small enough to
pass through the eyehole, the grip would be much too
small for a man to properly grasp it, and the wood
would be too small to resist the abuse that the tool
would take. Notably, there is one category of
percussive tools that does not require the handle to be
` 203~82a
--3--
inserted from the bottom and then affixed within the
eyehole as described above. This category includes the
pick or pick-mattock style of tool in which the eyehole
is so massive that even a large grip can be passed
through the eyehole. Traditionally the handles for
such pick or pick-mattock style tools are shaped so
that the upper end has a reverse taper allowing the
pick to be dropped over the grip onto the end farthest
away from the user so that the expanded end of wood is
large enough to lock the tool head in place and prevent
it from ever sliding off the upper end. Of course, the
tool head can always be removed in the same manner it
is placed on the handle, by removing it from the butt
or grip end.
Recent years have seen the development of
extremely strong composite tool handles formed of
reinforcing fibers cured within a resin composite.
Such reinforcing fibers may include fiberglass,
polyester, boron, kevlar or graphite, and suitable
resin composites include polyester, epoxy, phenolics,
etc. With the development of these composite
materials, the shaft underneath the tool head can now
be made with a cross-section small enough to pass
through the conventional eyehole of percussive tool
heads, yet have sufficient strength to withstand the
tremendous impact forces to be applied.
As advanced materials have been introduced to
replace wood, the materials have been either bonded
into the eyehole of the tool, substituting the bond for
the old traditional wedge, and/or welded such as metal
to metal. Whereas these techniques are suitable to
some degree for the manufacture of original tools in
which the handle is installed with appropriate
machinery and equipment at a factory, the techniques
are not suitable when practiced in the field. In the
case of bonding, composite shafts have been attached to
tool heads primarily by means of adhesives in the epoxy
field. When utilizing such adhesives, despite the
~ 4 2038820
continued development of these materials, it takes
care, precision and good workmanship to properly
install a replacement handle in a tool head, reliably
in the field with no secondary tools to assist. Even
in factories where the tool head is installed on a
production basis, high levels of quality control must
be practiced in order to insure that the head is
secured to the handle under all anticipated working
conditions. Further, since the high strength composite
shafts are usually inadequate in cross-sectional size
to be comfortable for a user's hands, a grip of rubber
or some other plastic material is usually molded onto
the shaft or subsequently bonded thereto in a manner
which guarantees that the grip will not accidentally
slide off the shaft.
Accordingly, there has been a need for a
highly reliable, simplified method by which a handle
can be installed onto a percussive tool head, in which
the handle is permitted to pass through the eyehole
from the upper end in a manner which effectively
prohibits the tool head from flying off the handle
unintentionally. A handle for use in such method must
include a minimum number of separate parts in order to
greatly simplify assembly of the handle to the tool
head, and also permit attachment of a grip which
comfortably fits a user's hands. Further, an improved
method of attaching a handle to a percussive tool is
needed which facilitates use of reinforced composite
tool handles as field replacements for older tools,
which overcomes drawbacks associated with fixing such
handles within the eyehole of the tool head solely by
means of an epoxy. Moreover, an improved tool handle
and method of attaching the handle to a percussive tool
is needed which simplifies the manufacture and assembly
of tools for both a field user and original equipment
manufacturers. The present invention fulfills these
needs and provides other related advantages.
` ~5- 2038820
SUMMARY OF THE INVENTION
The present invention resides in an improved
tool handle and method of attaching the handle to a
percussive tool in such a manner that the union will be
strong and invariable during the normal useful life of
the tool, and which may be utilized equally well during
the original manufacture of the tool or while replacing
the handle in the field. The improved tool handle
comprises, generally, a shaft retainer dimensioned for
partial insertion into a tool head through its eyehole
from the top end thereof, and a high strength handle
shaft which has its upper end fixed within an inner
cavity of the shaft retainer. The shaft retainer is
configured so that it is incapable of passing
completely through the eyehole, and thus provides an
anchor point against which the tool head is rigidly
positioned.
In a preferred form of the invention, a
percussive tool manufactured utilizing the improved
tool handle typically comprises a tool head having a
body and an eyehole through the body, wherein the
eyehole includes a taper expanding towards the top of
the tool head. The shaft retainer, which is
dimensioned for partial insertion into the tool head
through the eyehole from the top end thereof, forms a
tapered, generally frusto-conical slug. The shaft
retainer includes an outer surface portion generally
corresponding to a portion of the eyehole adjacent to
the top of the tool head, an upper enlarged portion
incapable of passing through the eyehole, and an inner
cavity having an opening opposite to the upper enlarged
portion. The inner cavity is slightly tapered so as to
expand towards an upper end of the cavity opposite to
the opening thereof. Further, the surfaces of the
inner cavity include keyways which extend generally
perpendicularly to the longitudinal axis of the shaft
retainer.
~ -6- Z038~20
The high strength handle shaft has an upper
end thereof inserted into the inner cavity of the shaft
retainer. The upper end of the handle shaft is bonded
by means of an adhesive within the inner cavity such
that the shaft extends substantially the length of the
eyehole and downwardly from a lower aperture thereof.
In order to increase the strength of the bond between
the handle shaft and the shaft retainer, at least one
of the surfaces of the upper end of the handle shaft
includes keyways similar to those keyways provided
within the inner cavity of the shaft retainer.
The shaft retainer includes means within the
inner cavity for rigidly aligning the longitudinal axis
of the handle shaft with the longitudinal axis of the
shaft retainer. The aligning means includes a
plurality of longitudinal ribs which protrude into the
inner cavity. These ribs frictionally engage the
handle shaft as it is inserted into the inner cavity.
The frictional engagement between the ribs and the
handle shaft is such that the handle shaft may be
lifted without a separation of the shaft retainer from
the handle shaft, even when the shaft retainer supports
a tool head.
Means are provided for bonding the upper end
of the shaft within the inner cavity of the shaft
retainer. Preferably, the bonding means comprises a
measured adhesive which is placed into the inner cavity
of the shaft retainer prior to insertion of the handle
shaft. As the shaft is inserted, the adhesive evenly
spreads between the handle shaft and the shaft
retainer, and after it cures, a rigid bond between the
two members is formed.
A grip ensheathes a lower end of the handle
shaft, and is preferably positioned so that one end of
the grip is situated adjacent to a lower portion of the
tool head. Preferably, the grip is molded directly
onto the lower end of the handle shaft prior to
assembly of the handle shaft to the shaft retainer.
'- ` 2038820
--7--
However, the grip may be slidably received onto the
handle shaft after assembly of the handle shaft to the
shaft retainer, and then the grip can be attached
securely to the handle shaft. If it is desired to
attach the grip to the handle shaft after the shaft
retainer is bonded to the handle shaft, in one
preferred form of the invention, a measured adhesive is
deposited into the grip so that as the grip is slid
over the handle shaft, the adhesive evenly spreads
between the grip and the handle shaft to form a bond
therebetween. In another preferred form, the handle
shaft is provided with one or more strips of barbs.
These barbs permit the grip to be slid onto the handle
shaft in one direction, but prevent removal of the grip
from the handle shaft in another.
The handle shaft has a generally uniform
cross-sectional dimension when taken perpendicular to
its longitudinal axis. This cross-sectional dimension
generally corresponds with the cross-sectional
dimension of the inner cavity when taken perpendicular
to the longitudinal axis of the shaft retainer. This
helps insure that a uniform, rigid and strong bond is
formed between the handle shaft and the shaft retainer.
The tool handle of the present invention
greatly facilitates the rehandling of tools in the
field. In the case where it is desirable to provide an
existing tool head with a new handle, the method simply
comprises the insertion of the tapered shaft retainer
into the tool eyehole from the top end thereof. A
measured adhesive is then placed into the inner cavity,
and the handle shaft is pressed into the inner cavity.
The adhesive uniformly spreads between the handle shaft
and the shaft retainer to form a bond therebetween. If
the grip has already been molded directly onto the
handle shaft, the- rehandling assembly process is
completed.
Other features and advantages of the present
invention will become apparent from the following more
2~820
detailed description, taken in conjunction with the
accompanying drawings which illustrate, by way of
example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the
invention. In such drawings:
FIGURE 1 is a front elevational view of a
percussive tool manufactured in accordance with the
invention, illustrating a shaft retainer partially
inserted into the eyehole of a sledge-type tool head, a
high strength handle shaft (in phantom) which is
inserted into the shaft retainer and extends outwardly
therefrom, and a grip molded onto the handle shaft;
FIGURE 2 is an enlarged exploded perspective
view of the working end of the exemplary percussive
tool shown in FIG. 1, illustrating the relationship
between the tool head and the components forming the
tool handle; namely, the manner in which the shaft
retainer is inserted into a tapered eyehole of the tool
head, wherein it receives a high strength handle shaft
which is fixed therein by means of a bonding agent, and
the manner in which a molded grip ensheathes the handle
shaft;
FIGURE 3 is an enlarged elevational view of
the shaft retainer illustrated in FIGS. 1 and 2;
FIGURE 4 is another elevational view of the
shaft retainer taken generally along the line 4-4 of
FIG. 3;
FIGURE 5 is an enlarged sectional view taken
generally along the line 5-5 of FIG. 3;
FIGURE 6 is an enlarged sectional view taken
generally along the line 6-6 of FIG. 3;
FIGURE 7 is an enlarged sectional view taken
generally along the line 7-7 of FIG. 3;
FIGURE 8 is an enlarged elevational and
partially sectional view taken generally along the line
8-8 if FIG 3;
2~38820
FIGURE 9 is an enlarged sectional view of a
portion of the internal cavity of the shaft retainer
illustrated by the area designated by the number 9 in
FIG. 8;
FIGURE 10 is an assembly-type drawing
illustrating the first step in assembling a handle to a
percussive tool head, wherein the percussive tool head
(in this instance a sledge) is illustrated in
cross-section, and wherein the shaft retainer is
inserted through an upper end of a tapered eyehole;
FIGURE 11 is another assembly-type drawing,
illustrating the next step assembling the tool handle
of this invention to a percussive tool head, wherein an
epoxy compound is placed into the internal cavity of
the shaft retainer, and a high strength handle shaft is
then inserted into the internal cavity;
FIGURE 12 is an enlarged, partially sectional
view of the percussive tool head, the shaft retainer
and the handle shaft after secured in place following
the assembly illustrated in FIG. 11;
FIGURE 13 is an enlarged sectional view taken
generally along the line 13-13 of FIG. 12;
FIGURE 14 is another assembly-type drawing,
illustrating the manner in which a grip may be slidably
received onto the handle shaft from a lower end thereof
and secured in place by means of an adhesive;
FIGURE lS is an enlarged, fragmented sectional
view taken generally along the line 15-15 of FIG. 14,
showing the assembly of the grip when bonded to the
handle shaft;
FIGURE 16 is an assembly diagram showing the
assembly steps of the tool handle to the percussive
tool head: and
FIGURE 17 is an enlarged, fragmented sectional
view taken generally along the line 17-17 of FIG. 14,
following assembly of the grip to the handle shaft, and
illustrating an alternative means for securing the grip
to the handle shaft, wherein a mechanical lock is
2~38820
--10--
employed having barbs which permit the grip to be slid
onto the handle shaft, but prevent removal of the grip
therefrom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in the drawings for purposes of
illustration, the present invention is concerned with
an improved tool handle, generally designated in the
accompanying drawings by the reference number 20. The
improved tool handle 20 comprises, generally, a tapered
slug or shaft retainer 22 which is configured for
insertion into an eyehole 24 of a tool head 26, which
receives and is bonded to a high strength handle shaft
28. A grip 30 is preferably molded onto a lower end of
the handle shaft 28 to ensheathe the handle shaft and
to position an upper end of the grip adjacent to a
lower portion of the tool head 26.
Tool heads which may be advantageously
utilized in connection with the improved tool handle 20
of the present invention comprise most of the broad
range of percussive-type tool heads. Such tool heads
typically include a body portion 32 and either a
single-taper or double-tapered eyehole 24. In both
instances, the eyehole 24 has a tapered portion which
expands toward a top 34 of the tool head 26. The
handle of the tool typically extends downwardly and
away from a lower or bottom portion 36 of the tool head
26.
In accordance with the present invention, and
as illustrated best in FIGS. 1 through 9 and 13 through
15, the shaft retainer 22 comprises a generally
frusto-conical slug which is dimensioned for at least
partial insertion into the eyehole 24 of the tool head
26. Preferably, the shaft retainer 22 is molded of a
glass-reinforced nylon material for high strength and
durability. The shaft retainer 22 includes an outer
surface body portion 38, an upper enlarged portion 40
2038820
--1 1--
which is dimensioned so as to be incapable of passing
through the eyehole 24, and an inner cavity 42 which
has an opening 44 opposite to the upper enlarged
portion 40.
As illustrated in FIGS. 4 and 8, the inner
cavity 42 is slightly tapered so as to expand towards
an upper end of the cavity opposite to the opening 44.
This taper is on the order of three degrees. As
illustrated in FIGS. 8 and 9, the surfaces of the inner
cavity 42 include keyways 46 which extend generally
perpendicularly to the longitudinal axis of the shaft
retainer 22. The purpose of these keyways is to
provide supplemental, anchoring channels into which an
adhesive may flow for purposes of bonding the shaft
retainer 22 to the portion of the handle shaft 28
inserted therein.
The high strength handle shaft 28 may be
manufactured of any suitable material, including metal,
but is preferably formed of a fiberglass-resin
composite material. The handle shaft 28 is
manufactured so that it has a generally uniform
cross-sectional dimension taken generally perpendicular
to its longitudinal axis, and is of sufficient length
to extend substantially the entire intended length of
the tool handle 20. The handle shaft 28 includes an
upper end 48 configured for insertion into the inner
cavity 42 of the shaft retainer 22. When the shaft
retainer 22 is securely positioned within the eyehole
24, the upper end 48 of the handle shaft 28 extends
substantially the length of the eyehole and downwardly
from the bottom edge 36 of the tool head 26. As
illustrated in FIGS. 12 and 13, at least one of the
outer surfaces of the upper end 48 of the handle shaft
28, includes keyways 50 which extend generally
perpendicularly to the longitudinal axis of the handle
shaft 28. Like the keyways 46, the keyways 50 provide
channeled anchoring slots for an adhesive 52 which is
utilized to bond the upper end 48 of the handle shaft
28 within the inner cavity 42 of the shaft retainer 22.
~_ 2G38820
-12-
Extending longitudinally within the inner
cavity 42 of the shaft retainer 22 are a plurality of
ribs 54. These ribs 54 provide means within the inner
cavity 42 for rigidly aligning the longitudinal axis of
the handle shaft 28 with the longitudinal axis of the
shaft retainer 22. The ribs 54 are dimensioned so as
to frictionally engage the upper end 48 of the handle
shaft 28 as it is driven into the inner cavity 42.
Since the outer dimension of the handle shaft 28 may
vary, depending on manufacturing tolerances, the ribs
54 are likely to be coined to some degree as the handle
shaft 28 is driven into the shaft retainer 22. This
tends to create a frictional engagement between the
ribs 54 and the handle shaft 28 which permits the
handle shaft to be lifted immediately after being
driven into the shaft retainer 22, without a separation
of the shaft retainer 22 and the tool head 26, from the
handle shaft 28. Further, the ribs 54 also ensure
sufficient space between the upper end 48 of the handle
shaft 28 and the walls of the inner cavity 42 of the
shaft retainer 22, to provide sufficient clearance for
the adhesive 52 to flow between the two members and
into the keyways 46 and 50. Once the adhesive 52 is
allowed to cure, a rigid, high strength bond is formed
between the shaft retainer 22 and the handle shaft 28.
The slight taper of the inner cavity 42 acts to
strengthen the bond between the shaft retainer 22 and
the handle shaft 28. Specifically, cured adhesive
between the handle shaft 28 and the walls of the inner
cavity 42 creates an incompressible wedge which cannot
be removed under normal circumstances from the shaft
retainer 22.
If the grip 30 has been previously molded
directly onto the handle shaft 28, then after the
handle shaft 28 is mated with the shaft retainer 22,
assembly of the tool handle 20 to the tool head is
complete. It may be preferable in some circumstances,
however, to assemble the grip 30 to the handle shaft 28
-13- 2038820
after assembly of the handle shaft to the shaft
retainer 22. If such further assembly of the grip 30
to the handle shaft 28 is necessary, the grip 30 is
slid over a lower end 56 of the handle shaft 28 (FIG.
14). An upper end 58 of the grip 30 may be situated
adjacent to the bottom surface 36 of the tool head 26.
The grip may be of any suitable length, however. The
grip 30 is preferably molded into a desirable shape
from any material which is strong and yet comfortably
handled by a user. It should be understood, however,
that the grip 30 itself primarily serves as a
convenient surface and mass for which the user can
grasp the tool handle 20. It does not provide the
strength characteristics of the tool handle 20.
Rather, the inherent strength of the tool handle 20 is
provided by the shaft retainer 22 and the handle shaft
28.
In either a rehandling operation or during
construction of a tool by an original equipment
manufacturer, in the case where one handle is suitable
for several different tool heads 26, wherein the tool
heads are not necessarily of the same height or
thickness between the upper and lower surfaces 34 and
36, a ferrule may be added to the tool handle 20. The
ferrule would typically be provided between the upper
edge of the grip 58 and the lower edge 36 of the tool
head 26. Preferably, the ferrule would be permitted a
limited adjustable cli~ing range relative to the grip
30 to accommodate various tool head thicknesses.
Following assembly of the grip to the handle
shaft as shown in FIG. 14, means are provided for
securely attaching the grip 30 to the handle shaft 28.
This can be accomplished in many different fashions,
however two preferred forms of attaching the grip 30 to
the handle shaft 28 are illustrated. In one
embodiment, illustrated in FIGS. 14 and 15, an adhesive
60 is placed within a cavity 62 of the grip 30 prior to
its being slid over the lower end 56 of the handle
-14- 2038820
shaft 28. This adhesive 60 tends to become uniformly
dispersed between the inner surface of the cavity 62,
and the outer surface of the handle shaft 28, and when
allowed to cure, forms a strong bond between the two
components.
An alternative means for securely attaching
the grip 30 to the handle shaft 28 is illustrated in
FIG. 17. In this embodiment, the securing means
comprises a mechanical lock which is illustrated as a
rack of unidirectional spring-steel barbs 64 fixed to
at least one surface of the handle shaft 28 below the
bottom edge 36 of the tool head 26. The barbs 64 are
constructed so as to allow the grip 30 to be slid onto
the handle shaft 28, but prevent removal of the grip
from the handle shaft. The design of the barbs 62
permits the surfaces of the cavity 62 of the grip 30 to
slide over the sharp edges thereof, but these same
sharp edges dig into the relatively soft material of
the grip 30 if the grip is pulled in an opposite
direction.
As mentioned previously, the handle shaft 28
is provided with a generally uniform cross-sectional
dimension taken perpendicular its longitudinal axis.
This cross-sectional dimension generally corresponds
with the cross-sectional dimension of both the inner
cavity 42 of the shaft retainer 22, and the
cross-sectional dimension of the cavity 62 of the grip
30, when each is taken perpendicular to its
longitudinal axis. This helps to insure that the
handle shaft 28 will not be permitted to twist or turn
relative to the shaft retainer 22, and further that the
grip 30 will not be permitted to twist and/or turn
relative to the handle shaft 28.
The assembly of the tool handle 20 is
illustrated best in FIGS. 2, 10-12, 14 and 16. Whether
the tool handle 20 is being utilized by an original
equipment manufacturer in a factory, or by a field user
in re-handling a tool, the present invention provides a
2~820
-15-
highly reliable, simplified method by which a handle
can be installed onto most types of percussive tool
heads, in a manner which effectively prohibits the tool
head from flying off the handle unintentionally.
First, as illustrated in FIG. lO, the shaft retainer 22
is banged or thumped into the eyehole 24 from the top
34 of the tool head 26. Since the upper portion 40 of
the shaft retainer 22 is incapable of passing through
the eyehole 24, there is no danger that the tool head
26 will ever fly off the tool handle 20. Further,
since the outer surface 38 of the shaft retainer 22 is
configured to generally match the taper of the eyehole
24, there is typically a solid area of contact between
the shaft retainer 22 and the body 32 of the tool head
26 within the eyehole 24. It has been found that the
tool handle 20 performs satisfactorily so long as a
minimum of twenty-five percent of the body 32
surrounding the eyehole 24 is in direct contact with
the outer surface body portion 38 of the shaft retainer
22.
Next, a measured quantity of the adhesive 52
is placed within the inner cavity 42 of the shaft
retainer 22. This is but a preparatory step which is
done prior to driving the upper end 48 of the handle
shaft 28 into the inner cavity 42.
As the upper end 48 of the handle shaft 28 is
driven into the inner cavity 42, the adhesive 52 flows
into the keyways 46 and 50, and spreads generally
uniformly between the handle shaft 28 and the shaft
retainer 22. The ribs 54 tend to align the handle
shaft 28 with respect to the shaft retainer, and
further to provide enough frictional force between the
handle shaft 28 and the shaft retainer 22, that the
lower end 56 of the handle shaft 28 can be grasped and
lifted, before the adhesive 52 has been allowed to bond
the handle shaft 28 to the shaft retainer 22, without
any separation of those two components. This is often
desirable in a manufacturing operation.
~ 2038820
-16-
In many instances the grip 30 will have been
previously molded directly onto the handle shaft 28
(FIG. 1). In this case, after the adhesive 52 has been
allowed to cure, assembly of the tool handle 20 to the
tool head 26 is complete. However, it is sometimes
preferable to ensheathe a lower portion of the handle
shaft 28 with a grip 30 of a selected length after the
upper end 48 of the handle shaft 28 is bonded within
the inner cavity 42 of the shaft retainer 22. Two
methods are illustrated in the accompanying drawings
for attaching the grip 30 to the handle shaft 28. In a
first of these embodiments, an adhesive 60 is placed
within the cavity 62 of the grip 30 in much the same
manner as the adhesive 52 is placed within the inner
cavity 42 of the shaft retainer 22. As the grip 30 is
slid over the handle shaft 28, the adhesive 60 becomes
generally uniformly dispersed between the walls of the
cavity 62 and the handle shaft 28. Once this adhesive
60 has been allowed to cure, the handling of the tool
is complete, and the completed tool handle 20 may be
used for all intended purposes.
In a second preferred method of attaching the
grip 30 to the handle shaft 28, a rack of barbs 64 is
attached by any suitable means to the handle shaft 28,
and then the grip is simply slid over the barbs 64 to
abut against the tool head 26. The barbs 64 prevent
removal of the grip 30 in much the same manner as the
adhesive 60 does.
From the foregoing it is to be appreciated
that the present invention provides a highly reliable,
simplified method by which a handle can be installed
onto a percussive tool head, which effectively
prohibits the tool head from flying off the handle
unintentionally. The tool handle 20 of the present
invention includes a minimum number of separate parts
which greatly simplifies assembly of the handle to the
tool head 26. Moreover, the grip 30 may be molded so
that it will comfortably fit a user's hands. The tool
2~3~820
-17-
handle 20 of the present invention facilitates use of
reinforced composite tool handles as field replacements
for older tools, and the present method overcomes
drawbacks associated with fixing such handles within
the eyehole of the tool head solely by means of an
epoxy.
Although a particular embodiment of the
invention has been described in detail for purposes of
illustration, various modifications may be made without
departing from the spirit and scope of the invention.
Accordingly, the invention is not to be limited, except
as by the appended claims.
