Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
~eretofore joint members of the prior art were
connected in pairs or more than one fastener was used
to complete the joint if there were more than two
members. Either way, other conventional joint
connections were expensive, complex and time consuming
in assembly, to say nothing of the relatively
unsightly joint which resulted.
Summary of the Invention
It is an object of the present invention to
provide an improved chain saw handle, guard and
housing interconnect which avoids the prior art
disadvantages; which is simple, reliable and
economical; which has three interfitted members; which
outer members have at least three active surfaces and
an inner member coacting with the outer members; which
has two members connected to the housing and the
members are wedge-locked to each other; which joint is
enclosed by a cover; and which joint is assembled by a
single ~astener means.
Other objects and advantages will be apparent from
the following description of the invention, and the
novel features will be particularly pointed out
hereinafter in the claims.
Brief Description of the Drawings
This invention is illustrated in the accompanying
drawings in which:
FIG. 1 is a perspective view of the chain saw
embodying the present invention,
FIG. 2 is an enlarged partial perspective view
showing the FIG. 1 improved handle, handguard and
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frame connection of the present invention, with the
housing cover removed.
FIG. 3 is an enlarged exploded partial perspective
view of the improved handle, handguard and frame with
fastener in the FIG. 2 configuration of the present
invention.
FIG. 4 is an enlarged exploded partial perspective
view of the improved handle, handguard and frame with
fastener of the present invent:ion as viewed from the
opposite side as that shown in FIG. 2.
FIG. 5 is an enlarged bottom view of handle and
handguard interlocking interconnection showing the
angle of the interface therebetween.
FIG. 6 is an enlarged partial sectional plan view
taken along line 6-6 of FIG. 2.
FIG. 7 is an enlarged partial sectional plan view
taken along line 7-7 of FIG. 2.
FIG. 8 is an enlarged partial sectional
elevational view taken along line 8-8 of FIG. 2.
FIG. 9 is an enlarged partial sectional
elevational view taken along line 9-9 of FIG. 2.
FIG. 10 is an enlarged partial sectional plan
view showing another embodiment of the present invention
in the same view as that shown in FIG. 6.
Description of the Invention
A portable power driven chain saw designated
generally 20 is shown in FIG. 1 and embodies the
present invention. The chain saw 20 has a housing 22
of clamshell construction in which there is a support
portion 24 to which a frame or bracket 26 (see FIG. 2)
and other operative components are affixed, and a
cover portion 28. A guide bar 30 extends forwardly
from the housing 22 and is affixed thereto by a
fastener 32. An endless saw chain 34 is entrained on
the guide bar 30 to be driven by a sprocket 35 powered
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from a suitable motive means as, for example, an
electric motor (not shown) housed in a motor casing
36. The motor is energized by a trigger switch 38
mounted in a rear handle 40 and connected to a source
of electricity by an electric cord 42.
The housing 22 shown in FIGS. 1 and 2 has a top
handle 44 which is disposed transversely across and
wraps around the housing 22 on the motor casing 36
thereof. The chain saw 20 may be conveniently and
easily controlled during operation by the operator
grasping the rear handle 40 with one hand and the top
handle 44 with the other hand. The handle 40 shown in
FIG. 1 is enclosed and widened at the bottom thereof
by a lower portion 46 which protects the operator's
hand from beneath.
A transverse handguard 48 illustrated in FIGS. 1
through 4 extends from an interlocked interconnection
with the frame 26 and handle 44 as described more
fully hereinafter, and defines a three-member joint,
designated generally as 50.
The stresses and forces placed on the joint 50
will be most severe during operation of the chain saw
20 and will result from various push-pull or rotary
motions of the chain saw 20, the handle 44 or the
handguard 48.
The frame or bracket 26 is formed integrally with
the housing 22 and is best seen in FIGS. 2, 3 and 4.
The outboard side hasashort vertical wall 52 and an
aperture 54 which receives a fastener 56 therethrough,
with the frame 26 and fastener 56 being hidden in
assembled position by the cover 28 of the housing 22
as shown in FIG. 1. A channel 58 is formed on the
inboard side opposite the wall 52. A short vertical
rear flange 60 bounds one end of the channel 58, while
a raised elongated ledge 62 runs the thickness of the
frame 26 and has a shorter step ledge 64 facing the
flange 60 formed at its base 66 which base is curved
between the ledge 64 and the flange 60. The frame 26
functions to provide contact surfaces which will
prevent rotation and provide torque transfer. It is
apparent that the frame 26 has at least three contact
surfaces.
The handguard 48 or, more simply, the guard 48 has
a flat substantially straightforward projection 68
having a flat top 70 and a curved outboard side 72,
with a bottom shoulder 73 terminating at the lower
section 78, and with the projection 68 angled at
section 74 forwardly and upwardly into a transverse
enlarged guard plate 76 that extends forwardly of and
parallel to the top section of the handle 44 as shown
in FIGS. 1 and 2. Below the curved side 72 of the
forward projection 68 is a lower section 78 having a
flat outboard side 80 with an aperture 82 therethrough
aligned with aperture 54 of the frame 26. The front
of the lower portion is a square contact surface 84.
The underside is a short shoulder 86. The bottom 88
of the lower section 78 is curved, with the rear being
recessed at 90 to form a flange 92. The inboard side
of guard 48 has a sloped slab 94 extending from base
88 to top 70 to terminate in a step flange 96 the
bottom of which includes the shoulder 86. A short
arcuate transverse arm 98 completes the back portion
of the forward projection 68. As best seen in FIG. 5,
the slab 94 is sloped at a suitable angle 0 which in
the preferred embodiment is within the range of 2 to
45 so as to assure the proper wedge-like action
between the contact surfaces. The side 80 will engage
the inboard side of the wall 52; thus placing the
recess 90 into engagement with the flange 60 as shown
in FIG. 6, and also engaging the contact surfaces 84
and 86, respectively, with the ledges 62 and 64.
The handle 44 shbwn in Figs. 1 through ~ has a top
section 100 which loops at 102 a.bout and forwardly of
the motor casing 36 to connect at the bottom of the
housing 22, while the other end thereof turns
downwardly in a vertical section 104 which terminates
in a curved base 106 having an aperture 108 spaced
therefrom in alignment with the apertures 54 and 82.
A shoulder 110 is formed downwardly facing in spaced
relation to the base 106. The shoulder 110 terminates
in a slabbed side 112 corresponding to the slab 94 of
the guard 48. A recess 114 is formed at the forward
end of the slab 112. A pair of spaced short shoulders
116 and 118 are formed at the rear and front of the
base 106.
The handle 44 has a circular cross section which
the guard 48 matches at the curved side 72 shown in
FIGS. 3 and 7, and the curved arm 98 shown in FIGS. 2,
4 and 7. The slabbed sides 94 and 112 have corresponding
slopes to provide contacting surfaces that will produce
wedge-like action therebetween, with the slabs 94 and
112 being shown in FIGS. 6 and 7, wherein the step flange
96 fits within the recess 114.
The top 70 is shown nested to the shoulder 110 in
FIGS. 8 and 9, and the shoulder 73 rests upon the
upper edge of the wall 52.
The ledge shown in FIGS. 4 and 6 extends under,
and in engagement with, the shoulders 86 and 118, while
the ledge 62 contacts the surface 84 and the forward side
of the lower section 104 adjacent the recess 114.
The handle 44 has at least three contact surfaces,
while the guard 48 has at least three contact surfaces
to engage each of the frame 26 and handle 44. The
fastener 56 has suitable threads which may be self-
tapping or otherwise as shown in FIGS. 3, 4 and
6. The fastener 56 is disposed from the outboard side
of the frame 26 through the aligned apertures 54 and
82 to be self-tapped within the aperture 108. The
fastener 56 completes the assembly of joint S0 so as
to interconnect and wedge-loclc the three members 26,
44 and 48, respectively, so as to provide the contact
and torque transfer surfaces therebetween which number
at least three per member.
Another fastener 116 of a second embodiment is
shown in FIG. 10 wherein the same interconnected,
interlocked members are shown. A curved washer 118
having locking teeth 120 engages the outer surface of
the handle 44 to be tightened into place by a nut 122
threadedly received upon the fastener 116 so as to
provide an independent connector for the fastener 116
which completes the assembly of the joint 50.
Accordingly, when a force is applied, one or more
of the three members 26, 44 or 48 will interact with
the other members along or upon the contact surfaces,
; ledges, shoulders or recesses so as to transfer the
torque therebetween and distribute and dissipate said
force. It will be understood that various changes in the
details, materia~s, arrangements of parts and operating
conditions which have been herein described and
illustrated in order to e~plain the nature of the
invention may be made by those skilled in the art
within the principles and scope of the invention.
