U.S. patent number 3,728,793 [Application Number 04/134,374] was granted by the patent office on 1973-04-24 for chain saw with damping means.
Invention is credited to Arthur M. Fullerton, Clifford Makinson.
United States Patent |
3,728,793 |
Makinson , et al. |
April 24, 1973 |
CHAIN SAW WITH DAMPING MEANS
Abstract
A chain saw is provided having means for more effectively
damping or reducing shocks and vibrations transmitted between the
chain saw body and the operator than means heretofore proposed for
this purpose. The chain saw has two separate handles, one near the
front and one near the rear, and lying in generally mutually
perpendicular planes. Each handle has shock-absorbing means
connecting end portions thereof to the body of the chain saw. Each
shock-absorbing means at each location is specifically designed to
provide maximum shock-absorbing characteristics for that position.
In one embodiment, the front handle with the shock-absorbing means
is readily adapted for mounting on existing chain saws.
Inventors: |
Makinson; Clifford (Rosemere,
Quebec, CA), Fullerton; Arthur M. (Toledo, OH) |
Family
ID: |
22463086 |
Appl.
No.: |
04/134,374 |
Filed: |
April 15, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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88886 |
Nov 12, 1970 |
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Current U.S.
Class: |
30/383;
173/162.1 |
Current CPC
Class: |
B27B
17/02 (20130101) |
Current International
Class: |
B27B
17/00 (20060101); B27B 17/02 (20060101); B27b
017/02 () |
Field of
Search: |
;143/32R ;173/162
;30/381-387 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schran; Donald R.
Parent Case Text
This is a continuation-in-part of our co-pending application Ser.
No. 88,886 filed Nov. 12, 1970, now abandoned.
Claims
We claim:
1. A chain saw comprising a chain saw body, a front handle, spaced
shock-absorbing means connecting spaced portions of said front
handle to said chain saw body, a rear handle spaced rearwardly from
and independent of said front handle, and spaced portions of said
rear handle being connected to said chain saw body.
2. A chain saw according to claim 1 characterized by said
shock-absorbing means for said front handle being located at end
portions of said front handle.
3. A chain saw according to claim 1 characterized further by
shock-absorbing means for said rear handle connecting said body to
end portions of said rear handle.
4. A chain saw according to claim 1 wherein said front handle is
C-shaped, the shock-absorbing means for the upper end of said
C-shaped front handle comprises bracket means, a shock-absorbing
element at one side of said bracket means, a second shock-absorbing
element at the other side of said bracket means, fastening means
extending through both of said shock-absorbing elements and said
bracket means and connected to said chain saw body.
5. A chain saw according to claim 4 characterized by said fastening
means comprising an elongate threaded shank, and a sleeve around
said shank and extending between outer end portions of said
shock-absorbing elements to limit the compression on said
shock-absorbing elements when said fastening means is
tightened.
6. A chain saw according to claim 1 characterized further by said
front handle being C-shaped said C-shaped front handle having a
tubular lower end and the shock-absorbing means at the lower end of
said front handle comprises a resilient element extending into the
lower end of said front handle, a rigid member centrally engaging
said resilient element, and a bracket connecting said rigid member
to said chain saw body.
7. A chain saw according to claim 2 characterized further by said
front handle having a lower end and an upper end and the
shock-absorbing means at the lower end of the front handle
comprises flange means extending outwardly from said lower end of
said front handle, two resilient elements transversely spaced
outwardly from said lower end and having ends connected to said
flange means, second flange means connected to the opposite ends of
said resilient elements, and means connecting said second flange
means with said chain saw body.
8. A chain saw according to claim 7 characterized further by said
means connecting said second flange means with said chain saw body
comprises an elongate member, one end of said elongate member being
affixed to said second flange means, and fastener means affixing a
portion of said elongate member spaced from said second flange
means directly to said chain saw body.
9. A chain saw according to claim 3 characterized by the upper
shock-absorbing means for said rear handle comprising a yoke with
spaced arms integrally connected to the upper end of said rear
handle, a shock-absorbing element connected to the end of each yoke
arm, and said chain saw body having recesses receiving the other
ends of said shock-absorbing elements.
10. A chain saw according to claim 9 characterized by said chain
saw body having a carburetor housing with side walls, said recesses
being formed in said side walls.
11. A chain saw comprising a chain saw body, a front handle located
generally in a vertical plane transverse to the longitudinal extent
of the chain saw, first shock-absorbing means connecting an upper
portion of said front handle to said chain saw body and extending
downwardly from said handle to said body, second shock-absorbing
means connecting a lower portion of said front handle and said
chain saw body and enabling limited pivotal movement of the lower
portion of said front handle, a rear handle spaced from and
independent of said front handle, and located generally in a
vertical plane parallel to the longitudinal extent of the chain saw
and perpendicular to the plane of the front handle.
12. A chain saw according to claim 11 wherein said first
shock-absorbing means comprises bracket means connected to said
front handle, a resilient shock-absorbing element located on
opposite sides of said bracket means, a fastener member extending
through both of said resilient elements and said bracket means, and
means connecting said fastener member to said chain saw body.
13. A chain saw according to claim 11 characterized by said second
shock-absorbing means comprising a resilient bushing extending into
a lower end of said front handle, and bracket means connecting a
central portion of said bushing to said chain saw body.
14. A chain saw according to claim 17 characterized by said second
shock-absorbing means comprising flange means extending outwardly
from the lower portion of said front handle, a pair of resilient
elements transversely spaced outwardly from said lower portion and
connected at ends to said flange means, second flange means
connected to the opposite ends of said resilient elements, and
means connecting said second flange means to said chain saw
body.
15. A chain saw according to claim 14 characterized further by said
means connecting said second flange means with said chain saw body
comprising an elongate member, one end of said elongate member
being affixed to said second flange means, and fastener means
affixing a portion of said elongate member directly to said
body.
16. A chain saw according to claim 11 characterized by third
shock-absorbing means connecting an upper portion of said rear
handle to said chain saw body, and fourth shock-absorbing means
connecting a lower portion of said rear handle to said chain saw
body.
17. A chain saw according to claim 2 characterized further by said
front handle having a lower end and an upper end, and the
shock-absorbing means at the lower end comprises at least one
resilient element spaced transversely from the axis of the lower
end of said handle, and means axially aligned with said lower end
and connecting said transversely spaced resilient element with said
chain saw body.
Description
This invention relates to a chain saw with means for damping shocks
and vibration between the chain saw body and the operator.
Chain saws equipped with high-torque, high-speed engines have a
tendency to produce a certain amount of vibration during operation.
Such saws with various anti-vibration designs have been heretofore
proposed. In these chain saws, the damping means employed have
tended to increase the cost of the chain saw excessively or to
require excessive design changes to embody the damping means. Such
saws also have not been as effective in damping or absorbing shocks
and vibrations as is desirable.
The present invention provides an improved chain saw having spaced,
separate handles, one near the front of the chain saw body and one
at the rear. Each of the handles has shock-absorbing or damping
means at end portions thereof, with each such means being
specifically designed to provide maximum damping effectiveness in
that particular location. Consequently, operator fatigue is reduce
and productivity is increased.
For the front handle, the upper shock-absorbing means for the upper
end of the handle is positioned at an angle to the vertical and
preferably generally perpendicular to the general direction in
which the operator's arm extends back and away from the front
handle. This places the resilient shock-absorbing elements of the
damping means in shear. The lower shock-absorbing means for the
lower end portion of the front handle enables limited pivotal
movement of the front handle relative to the chain saw body, with
the shock-absorbing elements placed in torsion. In one embodiment,
the shock-absorbing means and the front handle are particularly
suitable for replacing conventional front handles of existing chain
saws.
For the back handle, both upper and lower shock-absorbing means
connecting the handle to the chain saw body extend generally
perpendicularly to the longitudinal extent of the chain saw and to
the operator's arm, with the shock-absorbing means placed in shear.
The damping characteristics of this overall design exceed those of
damping means of chain saws heretofore known. The new
shock-absorbing provisions also are relatively inexpensive and
require minimum design changes in the basic chain saw body.
It is, therefore, a principal object of the invention to provide a
chain saw with improved damping means for minimizing transmission
of chain saw shocks and vibrations to the operator during operation
of the chain saw.
Another object of the invention is to provide a chain saw having
shock-absorbing means which are inexpensive and require minimum
modifications to the basic chain saw design.
A further object of the invention is to provide a chain saw front
handle with shock-absorbing means which can be mounted on an
existing chain saw in place of the conventional handle with minimum
changes.
Other objects and advantages of the invention will be apparent from
the following detailed description of a preferred embodiment
thereof, reference being made to the accompanying drawings, in
which:
FIG. 1 is a somewhat schematic view in perspective of a chain saw
embodying the invention;
FIG. 2 is a somewhat schematic front view in elevation of the chain
saw of FIG. 1, with the saw chain and guide bar removed;
FIG. 3 is a somewhat schematic side view in elevation of a rear
portion of the chain saw of FIG. 1;
FIG. 4 is an enlarged view in central, longitudinal cross section
of one shock-absorbing means or connection employed with the front
chain saw handle;
FIG. 5 is a view in transverse cross section taken along the line
5--5 of FIG. 4;
FIG. 6 is a fragmentary front view of another shock-absorbing means
or connection for the front chain saw handle, with parts broken
away and with parts in cross section;
FIG. 7 is a view in transverse across section taken along the line
7--7 of FIG. 6;
FIG. 8 is a left-end view in elevation of the means of FIG. 6;
FIG. 9 is a fragmentary view in generally horizontal cross section,
of upper shock-absorbing means for the rear handle of the chain
saw;
FIG. 10 is a fragmentary view in generally horizontal cross section
of lower shock-absorbing means for the rear handle of the chain
saw;
FIG. 11 is a schematic view in perspective of a chain saw,
indicated in dotted lines, with a modified front handle having
vibration- or shock-absorbing means;
FIG. 12 is a front view of the handle of FIG. 11, along with the
chain saw shown in solid lines;
FIG. 13 is an enlarged view in perspective, with parts broken away
and with parts in cross section, of an upper shock-absorbing means
or connection employed with the front chain saw handle of FIGS. 11
and 12;
FIG. 14 is a view in perspective of a lower shock-absorbing means
or connection for the front chain saw handle; and
FIG. 15 is a view in transverse cross section taken along the line
15--15 of FIG. 14.
Referring to FIG. 1, a chain saw embodying the invention is shown
somewhat schematically at 10 and includes a chain saw body 12, a
chain saw bar 14, and a saw chain 16. The chain saw 10 is of a
known design and includes an engine at an intermediate location in
the body 12 having a crankshaft connected to a drive shaft and
extending outwardly to a sprocket (not shown) which drives the saw
chain, the sprocket being under a guard 18. A muffler 20 is located
at the rear of the guard and a carburetor is located in an upper
housing 22 having a cover 24.
A front handle 26 of generally C-shaped configuration is located at
a forward portion of the chain saw body 12 in front of the chain
saw engine. A separate rear handle 28 extends rearwardly from the
chain saw body 12 and is located behind the engine of the chain
saw. Both of these handles are of generally known shapes or designs
and embody the invention without requiring any radical changes.
Both handles incorporate shock- or vibration-absorbing means which
dampen a substantial portion of the shock and vibration to which
the chain saw body 12 is subjected. Consequently, little of such
shock and vibration is transmitted to the chain saw operator who
conventionally stands generally to the rear of the chain saw,
holding the front handle 26 with one hand and the rear handle 28
with the other hand, controlling the chain saw speed and operation
through a trigger control 30. Other conventional controls for the
saw, well known in the art, are not shown.
Referring particularly to FIG. 2, the front handle 26 includes a
lower, generally horizontally extending leg 32, an intermediate,
generally vertically extending leg 34, an upper leg 36, and a
slanted portion 38. A tubular, resilient handle grip 40 is located
on the upper leg 36 with this grip providing an additional
cushioning effect for the operator. First shock-absorbing means
indicated at 42 connects the upper end of the handle 26 with the
chain saw body 12. Accordingly, an L-shaped arm 44 is suitably
affixed, as by welding, to the end of the upper leg 36 and has a
bracket 46 (FIGS. 4 and 5) connected to a lower portion thereof.
The bracket 46 includes an intermediate web 48 and end flanges 50
and 52. These have arcuately shaped edges to receive a hollow or
tubular member 54 which can be assembled as part of the bracket 46
and the arm 44 by a threaded fastener 56 (FIG. 5) extending through
a hole 58 in the tubular member 54, a hole 60 in the bracket web
48, and a tapped opening 62 in the arm 44. Access to the fastener
56 is provided through a larger opening 64 in the tubular member
54.
At the ends of the hollow tubular member 54 are two resilient
shock-absorbing elements or mounts 66 and 68. These have metal
plates at the inner ends forming cylindrical extensions 70 and 72
extending into the ends of the tubular member 54. Metal end plates
74 and 76 at the outer ends of the elements 66 and 68 form central
passages 78 and 80 through which a long bolt or threaded fastener
82 extends. This fastener 82 has a threaded end 84 received in a
tapped opening 86 of a mounting bracket 88, which is suitably
affixed to a portion of the chain saw body 12. A sleeve 90 extends
around the bolt 82 and limits the extent to which the resilient
elements 66 and 68 can be compressed by the tightening of the
fastener 82. Excess tightening otherwise could reduce the
shock-absorbing characteristics of the elements 66 and 68.
The tubular member 54 and the upper leg 36 of the handle 26 are
isolated from the chain saw body 12 through the shock-absorbing
elements 66 and 68. The longitudinal extent of the shock-absorbing
means 42 is located generally perpendicular to the arm of the
operator which extends rearwardly and upwardly from the front
handle grip 40. With this position, the shock-absorbing elements 66
and 68 are placed more in shear and are more effective in reducing
or damping shocks and vibrations from the chain saw body.
The lower end of the handle 26, and specifically the lower leg 32
thereof, is connected to the chain saw body by shock-absorbing
means generally indicated at 92. This includes a resilient
shock-absorbing element or bushing 94 having a cylindrical portion
96 slightly larger than the inner diameter of the handle leg 32,
with a flange 98 extending transversely beyond the outer diameter
of the leg 32. The bushing 94 also has a central passage 100 in
which is received a supporting rod or member 102 having a circular
flange 104 affixed thereto and backing up the bushing flange 98.
The member 102 is affixed to a bracket 106 (see also FIG. 8) which
flares upwardly and outwardly, and is attached to the chain saw
body 12 by fasteners 108.
The shock-absorbing means 92 further includes at least one threaded
fastener or machine screw 110 in the leg 32 in spaced relationship
from the bushing 94. The fastener 110 extends through a passage 112
in a metal cylinder or rod 114. A first resilient pad 116 is
located between the cylinder 114 and the inner surface of the leg
32, and a second resilient pad 118 is located between the outer
surface of the leg 32 and an arcuate recess 120 of the chain saw
body 12. A sleeve or collar 121 extends between the recess 120 and
the cylinder 114 to limit the maximum compression of the pads 116
and 118. An opening 122 in the leg 32 through which the fastener
110 extends is larger than the collar 121 to enable the leg 32 to
pivot somewhat relative to the fastener 110. A large opening 124 is
located in the exposed portion of the leg 32 for access to the
fastener. The fastener 110 is primarily used to prevent transverse
movement of the front handle 26 and the lower leg 32 thereof which
cannot be easily prevented solely by the rubber bushing 94. The
resilient pads 116 and 118 also tend to dampen the pivotal movement
of the lower leg 32 along with the rubber bushing 94 which is
placed in torsion during pivotal movement of the leg 32.
This design of the shock-absorbing means 92 thus enables the
overall front handle 26 to pivot to a limited extent relative to
the chain saw body 12. Actually, the chain saw body 12 can pivot
relative to the handle 26 when the upper leg 36 is held
substantially stationary by the operator. Consequently, the chain
saw body 12 can move to a limited extent under the influence of
vibration or shock while the upper leg 36 and the operator's hand
and arm remain substantially stationary.
An upper end 126 of the rear handle 28 is connected to a rear
portion, specifically the carburetor housing 22 of the chain saw
body 12, by shock-absorbing means 128. The shock-absorbing means
128 includes a yoke 130 terminating in forwardly extending, spaced
arms 132 and 134. Shock-absorbing elements or mounts 136 and 138
extend inwardly from the arms 132 and 134 and have metal end plates
140 and 142 with threaded passages 144 and 146. Threaded fasteners
148 and 150 extend through openings 152 and 154 of the arms and are
threadedly engaged in the passages 144 and 146 to hold the elements
securely in place. The inner ends of the elements 136 and 138 have
metal plates forming cylindrical extensions 156 and 158 which are
received in recesses 160 and 162 in the chain saw body 12 and
specifically in the side walls of the housing 22. The cylindrical
extensions 156 and 158 are telescopically received in the recesses
160 and 162 with no fasteners therebetween.
With the shock-absorbing means 128, the elements 136 and 138 are
placed in shear and provide utmost effectiveness in minimizing
transmission of shock and vibration from the body 12 through the
yoke 130 and the handle 28 to the hand and arm of the operator.
Further, effective control of the chain saw body through the handle
28 is retained by the operator, even with the resilient nature of
the elements 136 and 138, because of their wide spacing achieved
through the use of the wide yoke 130.
A lower end 164 of the rear handle 28 is connected to the chain saw
body 12 through fourth shock-absorbing means 166. This means
includes a narrow yoke 168 integrally connected to the handle end
164 and having forwardly extending arms 170 and 172. Resilient
shock-absorbing elements or mounts 174 and 176 have outer metal end
plates 178 and 180 with passages 182 and 184 therein. A long
fastener or through-bolt 186 extends through the passages 182 and
184 and through yoke arm openings 188 and 190 with a nut 192
located on the end of the bolt 186. The inner ends of the elements
174 and 176 have metal plates forming cylindrical extensions 194
and 196 which extend into an opening or cylindrical passage 198
formed in a lug 200 extending rearwardly from the body 12. The
fastener 186 also passes through the leg opening 198 and holds the
elements 174 and 176 securely in place relative to the lug 200.
However, the extent to which the elements 174 and 176 can be
compressed is limited by the rigid yoke arms 170 and 172.
The shock-absorbing elements 174 and 176 are placed in shear, as
are the elements 136 and 138. Again, maximum damping effectiveness
of this mount is achieved with this design.
Referring to FIG. 11, a chain saw 202 indicated in dotted lines
includes a chain saw body 204 having a modified front handle 206
shown in solid lines. The chain saw 202 otherwise can be similar to
that shown in FIG. 1. The front handle 206 has an upper
vibration-or shock-absorbing means which is less expensive, and a
lower vibration- or shock-absorbing means which is more readily
adapted for use with an existing chain saw than those used with the
front handle 26.
The front handle 206, as shown in FIG. 12, includes a lower leg
208, an intermediate, generally vertically extending leg 210, an
upper leg 212, and a slanted portion 214. A thick resilient handle
grip 216 is located on the upper leg, with this grip providing
additional damping means for the operator. An upper shock-absorbing
means or connection 218 connects the upper leg 212 of the handle
206 with the chain saw body 204 and a lower shock-absorbing means
or connection indicated at 220 connects the lower leg 208 of the
handle 206 to the chain saw body 204.
Referring more particularly to the details of the first
shock-absorbing means 218, as shown in FIG. 13, a generally
L-shaped arm 222 is suitably affixed to the end of the upper leg
212 and terminates in a bracket comprising upper and lower flanges
224 and 226 and an intermediate integral web 228. The flanges 224
and 226 have circular openings 230 and 232 which receive two
resilient shock-absorbing elements or mounts 234 and 236. These are
substantially identical, having metal plates 238 and 240 at the
inner ends terminating in cylindrical extensions 242 and 244 which
are received in the circular openings 230 and 232. The mounts also
have circular metal end plates 246 and 248 at the outer ends with a
long bolt or threaded fastener 250 extending therebetween. The
fastener has a threaded lower end 252 received in a tapped opening
of a mounting bracket 254 which is affixed to the chain saw body
204 by screws extending through suitable openings 256. A sleeve 248
is located around the bolt 250 and limits the extent to which the
elements 234 and 236 can be compressed by the tightening of the
fastener.
The bracket flanges 224 and 226 are isolated from the chain saw
body 204 through the shock-absorbing elements 234 and 236. As with
the shock-absorbing means 42, the longitudinal extent of the
shock-absorbing means 218 is located generally perpendicular to the
arm of the operator which extends rearwardly and upwardly from the
grip 216. Consequently, the shock-absorbing elements 234 and 236
are placed principally in shear and are more effective in reducing
or damping shocks and vibrations from the chain saw body. The
shock-absorbing means 218 is also less expensive to make than the
shock-absorbing means 42 because the bracket between the resilient
elements 234 and 236 can be made in one stamped piece.
The shock-absorbing means 218 can be readily mounted on an existing
chain saw body by removing the post extending up from the body at
the position where the bracket 254 would be and then tapping two
holes in the body for screws to mount the bracket 254 through the
holes 256.
A lower portion of the handle 206, and specifically the lower leg
208, is connected to the chain saw body 204 by the shock-absorbing
means 220. This includes a flange 258 affixed to the end of the
lower leg 208 and extending transversely thereof, terminating in
two spaced ears 260 and 262. Two resilient shock-absorbing elements
or mounts 264 and 266, which are identical, are affixed to the ears
260 and 262. The element 264, shown in section in FIG. 15, has a
pair of end plates 268 and 270 affixed thereto, with threaded studs
or shanks 272 and 274 extending outwardly therefrom. These can be
affixed to the plates 268 and 270 by end welding, for example. The
shock elements 264 and 266 are fastened to the ears 260 and 262 by
nuts 276 threadedly received on the studs 272.
The opposite ends of the elements 264 and 266 are affixed by nuts
278 on the studs 274 to a second flange 280 and specifically ears
282 and 284 thereof. The flanges 258 and 280 are parallel and are
maintained in spaced relationship by the elements 264 and 266,
there being no metal contact at all between the flanges. The second
flange 280 is affixed, as by welding, to an end of an elongate
tubular member 286. This member has a cylindrical supporting rod
288 therein adjacent holes 290 and 292 to provide strength for the
member. Fasteners are then received through the holes 290 and 292
into tapped holes in the chain saw body 204 to connect the elongate
member 286 to the body in the usual manner, no modifications
whatsoever being necessary for the chain saw body in this
location.
The shock-absorbing means 220 enables the handle 206 to pivot
somewhat relative to the member 286 and the housing 204 to
effectively absorb shock and vibration along with the
shock-absorbing means 218. In so doing, the elements 264 and 266
are primarily placed in shear. The chain saw body 204 can pivot
relative to the handle 206 with the upper leg 212 and the grip 216
being substantially still. Hence, the chain saw body 204 can move
somewhat under the influence of vibration or shock while the upper
leg, grip, and the operator's arm and hand remain substantially
stationary. Consequently, the front handle 206 and the
shock-absorbing means 218 and 220 not only effectively absorb shock
and vibration but can additionally be used with an existing chain
saw with minimum modification. Further, the shock-absorbing means
218 can be produced less expensively and still have the advantages
of the shock-absorbing means 42.
Various modifications of the above described embodiment of the
invention will be apparent to those skilled in the art and it is to
be understood that such modifications can be made without departing
from the scope of the invention, if they are within the spirit and
the tenor of the accompanying claims.
* * * * *