Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
21 8681 6
TOOL HANDLE
Field of Invention
This invention relates to a tool handle, and more particularly to a two-part
tool handle consisting of a grip which may, upon rotation, be fixably secured to the yoke
5 of the tool handle.
kground of Invention
Tool handle incorporating various means for fixably securing a grip
member between two arms of a yoke member of a tool handle have been known for over
100 years.
10Typical ofthese devices are the tool handles are the type disclosed in U.S.
519,515 and 4,794,667, which teach and describe a cylindrical grip member through
which a thru-bolt is passed along the longi~l-lin~l axis of the grip member. Such thru-bolt
secures together the two ends of a yoke of a tool handle, and also prevents detachment
of the grip from the yoke. Disadvantageously, however, these tool handle designs require
15components in addition to the yoke and grip member, namely an additional thru-bolt and
nut, which add to the expense and mechanical complexity in producing the tool handle.
Other prior art devices have successfully elimin~te~l the additional
component problem, but at the expense of more complex assembly and increased
assembling time. By way of illustration, U.S. Patent 3,107,937 in Figures 8A and 8B of
20such patent disclose a cylindrical grip bar 110 having end extensions 111 adapted to be
placed between holder arms 100 of a tool handle to thereby form the tool handle. The
21 8681 6
holder arms 100 were typically of metal, and the grip bar 110 of wood. Upon insertion
of the end extensions 111 into openings 121 in the holder arms 100, downwardly
projecting metal web portions 124 and upwardly projecting tongue portions 122 engages
slots 112 and 113 to thereby secure the grip bar 110 in the handle, and the flange portions
5 in the vicinity ofthe openings 121 then needed to be crimped or pinched against the end
extensions 111 and the tongue 122. This design is completely unsuitable where plastics,
including WDPE co-polymers and nylon plastics, are intended to be utilized for the
holder arms 100 since such design depends on the m:~teri~l used, particularly the web
portions 124 and 122, being permanently deformable when bent or crimped to thereby
10 m~int~in the grip bar 110 in place. This design cannot thus be employed and is entirely
unworkable when plastics are used as the yoke material.
Summary of the Invention
Despite the prior art designs, a real need exists for a tool handle which
may be assembled from two parts but simultaneously m~i"~ il-g ease of assembly, and
15 being particularly adapted where the materials of the tool handle, particularly the yoke
arm members of the tool handle, are to be constructed of HDPE plastic or other relatively
deformable m~teri~l.
Accordingly, in a broad aspect of this invention, there is provided a tool
handle of typical D-grip configuration for a manual implement such as a snow shovel,
20 which may be constructed if desired of a plastic material, and which may be assembled
from merely its two structural components, namely a grip member and a yoke member,
and which may when assembled create a fixed structure with the grip member lockably
21 8681 6
-
securing the two ends of the yoke member together to form a D-shaped tool handle.
Thus in one broad aspect the present invention comprises a tool handle
having a yoke member, such yoke member having at one end thereof means to permit
securement to a shaft of a tool and at an opposite end thereof having two elongate arm
5 members, with the ends thereof being in mutually spaced-apart relationship to each other.
An elongated grip member, generally cylindrical in shape, is further provided, having
mutually opposite ends adapted for placement between the ends of the two arm members.
Each mutually opposite end of the grip member is adapted to engage a respective distal
end of each of the arm members in a first position, and upon rotation to a third position
10 to become lockingly secured at each of its ends to the arm members. Importantly, detent
means is provided on at least one of i) each of the ends of the grip member; and/or ii) the
distal ends of the yoke member; to allow lockable engagement of the grip member to the
yoke member when the grip member is rotated from its first position to the third position.
In a ~l~relled embodiment, each of the mutually opposite ends of the grip
15 member are provided with tab members protruding outwardly adapted for insertion into
a respective ap~llu[e in a distal end of an arm member ofthe yoke. Either the tab member
or the aperture is further provided with a protruding member, and a corresponding
recessed portion is then correspondingly provided in the aperture, or vice versa. Such
protruding member on either the tab member or the aperture, and the corresponding
20 recessed portion on the aperture or tab member, as the case may be, upon the tab
members being inserted in the corresponding apertures and the grip member then being
rotated from this first position to a third position, are caused to m~tingly engage to
thereby lockingly engage the grip member to the yoke.
2186816
-
- 4 -
Accordingly, in this further embodiment, there is further provided a yoke
member having at one end thereof means to permit securement to a shaft of a tool, and
at an opposite end thereof two elongate arm members, each arm member at its distal end
having an aperture whereby each aperture of each arm member is in opposed mutually
spaced-apart relationship with the other. An elongate grip member having mutually
opposite ends, and tab members protruding outwardly from each of said mutually-
opposite ends adapted for insertion into a respective aperture in a distal end, are also
provided. Each of said tab members and each of said apertures possess, respectively, a
protruding member and a corresponding recessed portion, wherein each of said tabmembers when inserted in said apertures and the grip member rotated from a firstposition to a second position, causes a condition of interference between the tab members
and the aperture. Further rotation of the grip member from the second position to a third
position causes the respective protruding member to matingly engage the corresponding
recessed portion so as to lockingly engage the grip member to the yoke member and
elimin~te the interference condition.
Brief Dt~ ,lion of the Drawin~
Further embodiments incorporating various pe" "~ ons will appear from
the following detailed description ofthe invention, taken together with the acco~ ~lyhlg
drawings, in which:
Figure lA is a perspective view of one part of the two component
handle design of the present invention, depicting the yoke
2186816
member;
Figure lB is a perspective view of the other part of the two-
component handle design of the present member,
depicting the grip member in a first position in which it
would be inserted between the arms of the yoke member;
Figure lC is a perspective view of the grip member, shown in the
position it would be rotated to, within the yoke arm
members, namely the third position, to achieve
securement of the grip member to the yoke.
Figure 2 is a top view of the tool handle specifically the yoke
member and arms, without the grip member installed;
Figure 3 is a side elevation view of the yoke member shown in
Figure 2;
Figure 4 is a cross-sectional view taken along plane 4-4 of Figure
3;
Figure 5 is a top view of the tool handle, showing the yoke member
with the grip member installed between the link arms;
Figure 6 is a side elevation view of the tool handle shown in Figure
Figure 7 is a cross-sectional view taken along plane 7-7 of Figure
6;
Figure 8 is a side elevation view of an alternative embodiment
design of the yoke and grip member, shown with the grip
21 8681 6
-
member installed within the yoke member; and
Figure 9 is a cross-sectional view taken along plane 9-9 of Figure
8, knowing both the grip member and one arm member of
the yoke in cross-section.
5 Description of the Preferred Embodiment
Figures lA, lB, and lC as well as Figure 5 show the tool handle 10 of the
present invention, having a yoke member 12 which at one end thereof possesses means
in the form of an orifice or cavity 14 to permit placement of a shaft 16 of a tool (not
shown) to allow the tool handle 10 to be secured thereto.
At the opposite end of the yoke member 12 are two elongate arm members
18, each arm member 18 at its distal end having an aperture 20 whereby each aperture 20
of each arm member 18 is in opposed spaced apart relationship to the corresponding
aperture 20 on the other arm member 18.
The yoke member 12 preferably of a high density polyethylene plastic
15 (HPDE Plastic) or nylon plastic to allow injection molding thereof to the shape shown,
and in the prt;r~ d embodiment is in its entirety made from an HPDE injection molded
plastic. The shaft 16 to which such tool handle 10 is secured, usually by friction fit, or
other means, is usually of wood but may be of other materials.
A cylindrical elongate grip member 22, having mutually opposite ends 24,
20 is provided. Such grip member 22 is initially detached from the yoke member 12, to
allow for material of a shock-absorbing nature, such as a polyethylene or styrofoam
2186816
sleeve (not shown) to be fitted over such grip member 22 to assist in comfort of use of
the tool handle 10, prior to being lockingly secured to the yoke member 12. Such grip
member 22 is also preferably of a plastic material, such as high density polyethylene or
a nylon plastic, and is in the preferred embodiment made in its entirety from a HPDE
S injection-molded plastic.
Tab members 26 extend from each ofthe mutually opposite ends 24 ofthe
grip member 22. The grip member 22 is adapted for placement intermediate the arm
members 18 so that the tab members 26 may be inserted within the respective aperture
20 of each arm member 18 as shown in Figures lA - lB in a first position, and adapted
10 to allow at least a 90~ rotation within such aperture (Figure lC) to a third position to
alow such grip member 22 to become lockingly secured, as hereinafter explained, at each
of its ends 24 to the respective arm members 18.
Detent means, in the form of a raised protruding member 30 is provided,
as shown in Figures lB and lC, and a corresponding recessed groove portion 32 in said
15 apertures 20 is likewise provided, as shown in Figure lA. When the grip member 22 and
in particular its tab members 26 with the protruding member 30 thereon is inserted in the
corresponding aperture 20 in the arm members 18, and rotated from a first position to a
second intermediate position (not shown), an hlL~lr~.ellce condition is created between
the protruding member 30 and surrounding portions of the aperture 20. The interference
20 condition is caused, in the first embodiment shown in Figures 1 - 7, by dimension 't' (see
Figure lB and Figure 7) being smaller than dimension 'w', as shown in Figure 4.
Alternatively, in a second embodiment of the tool handle 10, the interference condition
2186816
is caused by the dimension 'x' consisting of the thickness of the tab member 26 and the
protruding member 30 being greater than dimension 'y', as shown in Figure 9.
Advantageously, the creation of an interference condition in the
intermediate position (ie second position) assists in en~uring that the grip member 22 will
S not rotate back from the third position back to the second andlor first position to thereby
become disengaged from the yoke member 12. As seen from above, two different
embodiments (Figure 7 and Figure 9) are disclosed for en~uring an interference condition
exists in the second position. In the first embodiment (Figures 1 - 7) due to (limen~ion 't'
being smaller than dimension 'w' (see Figure 4), a tensile force is created in end 24 of
10 the grip member due to component 40 being squeezed between tab member 26,
protruding member 30, and surface S0 of the grip member. In the second embodiment
(Figures 8 & 9), due to dimension 'x' being greater than dimension 'y', protruding
member 30 on tab member 26 is forcibly m~int~ined in recessed groove portion 32 by
pressure from wall 52 in aperture 20. Advantageously, the interference will gradually
l S increase upon rotation from the first position to the second position, and upon further
slight rotation to such third position where the protruding member 30 engages the
recessed portion 32, the interference condition no longer exists.
In both embodiments, upon further rotation of the grip member 22 to a
third position (see Figure 7 and Figure 9), the interference condition is removed when the
20 protruding member 30 m~tingly engages the recessed portion 32, thereby preventing
further rotation of the grip member 22. The two arm members 18 are then held together
by the tab member 26 abutting the inner surface 40 of the aperture 20 within each arm
member 18 (see Figures 7 and 9).
21 8681 6
To allow rotation of the grip member 22 through a condition of
interference in the second position, and on to a third position where the protruding
member 30 suddenly "snaps" into the recessed area 32 of the aperture 20, it is necessary
that the protruding member 30 or areas within the aperture 20 be resiliently deformable
S or flexible to allow the m~terial~ to deform in an hlte~ ce condition, and to restore
themselves to their normal dimensions when the condition of interference ceases in the
third position.
Of note, it is not necessary that the protruding member 30 be situate on
the tab member 22. As may accordingly now be clearly apparent to a person skilled in
10 the art, the protruding member 30 may be situate in the aperture 20, and the recessed
portion situate on the tab member 22, and the two matingly engage each other in the third
position.
The manner of assembly of the tool handle is now described. In particular,
to lockably install the grip member 22 within the yoke 12, the tab members 26 of the grip
15 member 22 are inserted into the corresponding apertures 20 in each arm member as
shown in Figures lA with Figure lB. The grip member 22 is then rotated through a
condition of interference, wherein protruding member 30 and/or the aperture 20
resiliently deforms to allow such rotation. Upon rotation ofthe grip member 22 to a third
position (Figure lA with Figure lC), the protruding member 30 m~tingly engages the
20 recessed portion 32, and the interference condition is removed. The corresponding arm
members 18 are prevented from being pulled apart and the grip member 22 thereby
removed due to the tab members abutting surface 40 of the aperture 20.
Many variations and modifications will now occur to those skilled in the
2186816
- 10-
art, and the invention is not limited to the preferred embodiments shown in the drawings.
For a complete definition of the invention reference is to be made to the appended claims.
