Information
-
Patent Grant
-
6438852
-
Patent Number
6,438,852
-
Date Filed
Tuesday, January 23, 200124 years ago
-
Date Issued
Tuesday, August 27, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
A portable power working machine has an L-shaped top handle having a top grip portion that extends longitudinally above and parallel to the top of a main housing and a rear coupling portion that extends along the rear portion of the main housing. A side handle has a front grip portion that is joined to and extends horizontally and laterally from the front end of the top grip portion of the top handle and a diagonal grip portion which curves out and down from the front grip portion and extends diagonally straight as viewed in side elevation from the front grip portion toward the lower end of the rear coupling portion of the top handle. A starting footstool contiguous to a lower end of the diagonal grip portion extends horizontally to the vicinity of and is joined to the lower end portion of the rear coupling portion of the top handle.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a portable power working machine, such as a chain saw, a power cutter, a hedge trimmer and the like. Such machines ordinarily have a top handle, which is usually gripped by the operator with his right hand, and a side handle, which is usually gripped with his left hand. The handles are attached to a main housing. A working member, such as a saw chain or a cutter, extends forwardly from the main housing.
In a conventional portable power working machine of the aforementioned kind, the top handle is constituted by a top grip member, which is located above and oriented parallel to a top surface of the main housing and extends in the longitudinal direction of the main housing. The front and rear ends of the top grip member are connected with the front and rear end portions of the upper surface of the main housing, respectively. The side handle is generally a C-shaped tubular body, one end of which (the upper end) is secured to the main housing close to the front end of the top grip member, and the other end of which (the lower end) is secured to a bottom portion of the main housing, at a location vertically below where the upper end is secured to the main housing. Both ends of the side handle are secured to the main housing at about the same location in the longitudinal direction of the main housing, and therefore, the side handle lies in a vertical plane orthogonally intersecting the longitudinal direction of the main housing.
In the operation of the portable power working machine of the type described above, the working position (or posture) thereof is not necessarily the same all the time, but may be required to be varied depending on the working condition. For example, the operator may sometimes hang the working machine from a branch of a tree using a rope, for instance. Depending on the working posture, the operator may have difficulty suitably gripping the side handle, which, as mentioned above, lies in a vertical plane orthogonally intersecting the longitudinal direction of the main housing, thereby badly affecting the working efficiency.
With a view to solving the above problem, there has been proposed, as set forth in Japanese Patent Publication No. 2931234 (U.S. Pat. No.5,570,512), a portable power working machine (a chain saw) wherein the aforementioned other end (lower end) of the side handle is secured to a lower edge portion of the proximal (rear) end of the main housing, and the central portion of the side handle is curved downwardly diagonally, as viewed from the side.
Although the side handle can be easily gripped, irrespective of the working posture of the machine, the vibrations of the top handle and the main housing are transmitted to the side handle, inasmuch as the other end (lower end) of the side handle is secured to a lower edge portion of the proximal (rear) end of the main housing (recoil starter case). Hence, the operator is not able to sense an integrity between the top and side handles, thus diminishing the operability of the machine. Furthermore, since part of the side handle extends over the main housing, it is required, when performing maintenance or repair work on components housed inside the main housing (such as maintenance and inspection of the prime mover and the recoil starter), to dismount the side handle from the top handle as well as from the main housing, thereby making the performance of maintenance inconvenient.
BRIEF SUMMARY OF THE INVENTION
The present invention has been made in view of overcoming the aforementioned problems. It is an object of the present invention to provide a portable power working machine having a side handle that is easy to grip, irrespective of the working posture of the machine. It is a further object to minimize the transmission of vibrations of the main housing to the side handle, thereby giving the operator a feeling of integrity between the top and side handles and improving the operability of the machine. Another object is to make it easier for the operator to perform maintenance work on the components housed inside the main housing.
With a view to attaining the aforementioned objects, there is provided, according to the present invention, a portable power working machine which includes a main housing having a front end portion, a working member that extends forwardly from the front end portion of the main housing, and a prime mover housed in the main housing. A top handle is secured to the main housing. The top handle is L-shaped as viewed in side elevation and has a top grip portion disposed above and extending parallel to a top surface of the main housing and in the longitudinal direction of the main housing. A rear coupling portion of the top handle extends from the top grip portion downwardly along the rear side of the main housing. The front end of the top grip portion is connected with the front end portion of the top surface of the main housing. A rear coupling portion of the top handle is coupled with a rear end portion of the main housing. A side handle includes a front grip portion, which extends horizontally and laterally from the vicinity of the front end of the top grip portion of the top handle, and a diagonal grip portion, which curves laterally and downwardly from the front grip portion and then extends diagonally straight, as viewed in side elevation, toward the lower end of the rear coupling portion of the top handle. A starting footstool is contiguous to a lower end of the diagonal grip portion and extends horizontally to the vicinity of the lower end of the rear coupling portion. One end portion of the front grip portion of the side handle is connected directly to or molded integrally with the top grip portion of the top handle at a location near the front end thereof. A rear end portion of the starting footstool is connected directly to or molded integrally with the rear coupling portion of the top handle at a location near the lower end thereof.
In preferred embodiments of the portable power working machine according to the present invention, the starting footstool is molded integrally with the side handle.
In a preferred embodiment, said one end portion of the front grip portion of the side handle is connected directly to the top grip portion of the top handle by a bolt or the like, and the rear end portion of the starting footstool is connected directly to the rear coupling portion by a bolt or the like.
Preferably, the starting footstool is configured in plan view such that the outer side wall thereof gradually converges from the front end portion thereof toward the vicinity of the rear end portion thereof so as to make it gradually approach the main housing.
In another preferred embodiment, a vibration isolating member is interposed between the vicinity of the front end of the top grip portion of the top handle and the top surface of the main housing.
In a further preferred embodiment, a vibration isolating member is interposed between the lower end of the rear coupling portion of the top handle and a lower end portion of the rear end portion of the main housing.
In a further preferred embodiment, the diagonal grip portion of the side handle has an oval cross section whose inner circumference has a larger radius of curvature than that of the outer circumference thereof.
The present invention is applicable to such portable power working machines as chain saws, power cutters, hedge trimmers, etc. In the case where the working machine is a chain saw, the working portion thereof is constituted by a saw chain set comprising a guide bar attached to the main housing and a saw chain trained around the guide bar.
According to a preferred embodiment of the portable power working machine, which is constructed according to the present invention, the top handle is L-shaped in side elevation and is constituted by a top grip portion which is located above and parallel to the top surface of the main housing and extends in the longitudinal direction of the main housing and by a rear coupling portion, which extends from the top grip portion toward the rear side of the main housing. The front end of the top grip portion is connected with the front end portion of the top surface of the main housing, and the rear coupling portion is coupled with the rear end portion of the main housing. Furthermore, the side handle is constituted by the front grip portion which extends horizontally and laterally from the vicinity of the front end of the top grip portion and by the diagonal grip portion which curves down from the front grip portion and then extends diagonally straight, in the side view thereof, from the front grip portion toward the lower end of the rear coupling portion. The end portion of the front grip portion of the side handle is connected directly to or molded integrally with the portion of the top grip portion of the top handle which is located close to the front end of the top grip portion.
Further, preferably, the starter footstool is formed integrally with and contiguous to the diagonal grip portion (or a lower end thereof) of the side handle. Since the starter footstool is disposed in this manner, the working machine can be firmly fixed in place by placing one's foot on the starter footstool on the occasion of pulling the recoil starter handle, thereby facilitating the starting of the working machine.
Furthermore, since the starter footstool extends horizontally to the vicinity of the lower end portion of the rear coupling portion and the rear end portion of the starter footstool is connected directly to or molded with the lower end portion of the rear coupling portion, the side handle is enabled, via the starting footstool, to be connected directly to or molded integrally with the lower end portion of the rear coupling portion. As a result, it is possible to make it easy to grip the side handle (the front grip portion and the diagonal grip portion) irrespective of the working posture of the machine. Further, it is possible, with a portable power working machine embodying the present invention, to give the operator a feeling of integrity between the top and side handles, thus making it possible to improve the operability of the machine as compared with the conventional portable power working machine wherein the other end (lower end) of the side handle is secured directly to a lower edge portion of the proximal (rear) end of the main housing (recoil starter case).
Furthermore, since it is no longer required, when performing maintenance on the components housed inside the main housing (such as maintenance and inspection of the prime mover and the recoil starter), to dismount the side handle from the top handle, the maintenance work can be facilitated.
Additionally, since a vibration isolating member is interposed between the vicinity of the front end of the top grip portion and the top surface of the main housing, and at the same time, since a vibration isolating member is interposed between the lower end of the rear coupling portion of the top handle and a lower end portion of the rear end portion of the main housing, vibration of the top and side handles can be minimized, thus giving the operator a feeling of improved integrity and making it possible to improve the operability of the working machine.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1
is a plan view showing one embodiment of a chain saw, which is representative of portable power working machines according to the present invention;
FIG. 2
is a left side view of the chain saw shown in
FIG. 1
;
FIG. 3
is a rear side view of the chain saw shown in
FIG. 1
;
FIG. 4
is a perspective view, illustrating the side handle and the starting footstool, which are mounted on the chain saw shown in
FIG. 1
;
FIG. 5
is a cross-sectional view taken along the line V—V of
FIG. 1
; and
FIG. 6
is a cross-sectional view taken along the line VI—VI of FIG.
1
.
DESCRIPTION OF THE EMBODIMENT
The illustrated embodiment of the present invention will be explained with reference to the attached drawings as follows.
Referring to
FIGS. 1
,
2
and
3
, a chain saw
10
comprises a main housing
12
made of a synthetic resin, and a guide bar
21
around which a saw chain
22
is trained so as to constitute a working member (working portion). The guide bar
21
extends forwardly (the arrow F) from a right portion of the front end
12
f of the main housing
12
.
An air-cooled two-stroke gasoline engine
70
, the details of which are omitted, serves as a prime mover by rotatably driving the saw chain
22
. The engine
70
is housed inside the main housing
12
. A recoil starter case
12
A is detachably attached to the left sidewall of the main housing
12
and includes a recoil starter handle
25
at a rear portion on the left side of the engine
70
for starting the engine
70
. A hand protection guard
15
is disposed over the front end
12
f of the housing.
A top handle
30
of L-shape in side elevation is located above the top surface
12
a
of the main housing
12
and extends from the front portion to the rear portion
12
b
of the main housing
12
. Further, a side handle
40
is disposed on the left side of the main housing
12
(on the side where the recoil starter case
12
A is disposed).
The top handle
30
is constituted by a top grip portion
30
A, which is located above and extends parallel to the top surface
12
a
of the main housing
12
and in the longitudinal direction of the main housing
12
, and by a rear coupling portion
30
B, which extends from the top grip portion
30
A toward the rear side of the main housing
12
. A front end
30
a
of the top grip portion
30
A is connected via a vibration isolating member
60
with a bracket
12
d
, which projects upwardly from the top surface
12
a
. The lower end
30
b
of the rear coupling portion
30
B is coupled with a lower end
12
c
of the rear end portion
12
b
of the main housing
12
by means of a bolt
67
(see FIG.
6
).
The top handle
30
is of a two-piece structure, consisting of a left side half body
31
and a right side half body
32
. The left side half body
31
is constituted by the left side half of the top grip portion
30
A and by the rear coupling portion
30
B, while the right side half body
32
is constituted only by a right half of the top grip portion
30
A. The top grip portion
30
A is provided with an engine stop switch
35
, a throttle safety lever
36
and a throttle trigger
37
. On the rear side of the rear coupling portion
30
B, there is detachably mounted an air cleaner cover
17
equipped with a detaching thumbscrew
19
. The interior of the rear coupling portion
30
B houses a diaphragm carburetor
50
for feeding an air-fuel mixture to the engine
70
through a flexible tube
51
.
The side handle
40
is tubular in configuration and is constituted by a front grip portion
41
, which extends horizontally and leftward from the vicinity of the front end
30
a
of the top grip portion
30
A, and by a diagonal grip W portion
42
, which curves downwardly from the front grip portion
41
and after passing through nearly the center of gravity G of the working machine further extends diagonally straight (in the side view thereof) toward the lower end of the rear coupling portion
30
B. A constricted portion
40
a of the front grip portion
41
is inserted into an inner partitioning wall
33
a
of a coupling boss
33
, which projects in the vicinity of the front end
30
a
of the top grip portion
30
A, thereby enabling the front grip portion
41
to be integrally connected, by a bolt
62
or the like (FIG.
5
), with the top grip portion
30
A.
A starter footstool
50
of triangular configuration in the plan view thereof is disposed contiguous to a lower end (the other end) of the diagonal grip portion
42
of the side handle
40
and horizontally extended up to the vicinity of the lower end portion
30
b
of the rear coupling portion
30
B. The rear end portion
50
b
of the starter footstool
50
is integrally connected, by bolts or the like, with a coupling boss
34
which projects in the vicinity of the lower end portion
30
b
of the rear coupling portion
30
B.
The starting footstool
50
is configured in plan view such that the outer sidewall
50
s
thereof gradually converges from the front end portion
50
a
thereof toward the vicinity of the rear end portion
50
b
thereof so as to make it gradually approach the main housing
12
. The converging sidewall
50
s
prevents the working machine
10
from being caught by the branches of a tree when, for example, it is hung by a rope from a tree.
For the purpose of enabling the operator to easily grip the side handle
40
, as shown in
FIG. 2
(hatched region) and
FIG. 4
, the diagonal grip portion
42
of the side handle
40
is made oval in cross-section (nearly flattened) in such a manner that the inner circumference
42
i
has a radius of curvature larger than that of the outer circumference
420
thereof (the side which is contacted by the palm of the operator's hand).
As shown in
FIGS. 4
to
5
, the side handle
40
is provided, at the end portion
40
a
thereof, with an end wall
41
a having a tapped hole
45
, and the starting footstool
50
is provided, at the rear end
50
b
thereof, with an end wall
52
having a bolthole
46
.
Further, the coupling boss
34
, which projects in the vicinity of the lower end
30
b
of the rear coupling portion
30
B of the top handle
30
and to which the end wall
52
of the rear end (the other end)
50
b
of the starting footstool
50
is attached, is interconnected, by means of bolts
67
or the like, with the lower end
12
c
of the rear portion
12
b
of the main housing
12
with a vibration isolating spring
65
being interposed therebetween.
With the chain saw
10
of the embodiment, which is constructed as described above, the top handle
30
is L-shaped in the side view thereof and is constituted by the top grip portion
30
A which is located above and parallel to the top surface
12
a
of the main housing
12
and extends in the longitudinal direction of the main housing
12
and by the rear coupling portion
30
B which extends from the top grip portion
30
A toward the rear side of the main housing
12
. The front end
30
a
of the top grip portion
30
A is connected with a front end portion
12
f
of the top surface
12
a
, and the rear coupling portion
30
B is coupled with a rear end portion
12
b
of the main housing
12
. The side handle
40
is constituted by a front grip portion
41
, which extends horizontally and laterally from the vicinity of the front end
30
a
of the top grip portion
30
A of the top handle
30
, and by a diagonal grip portion
42
which curves out and down from the front grip portion
41
and then extends diagonally straight in the side view thereof toward the lower end of the rear coupling portion
30
B. The one end portion
40
a
of the front grip portion
41
is connected directly with the coupling boss
33
, which projects close to the front end
30
a
of the top grip portion
30
A.
The starting footstool
50
is integrally connected with the lower end
40
b
of the diagonal grip portion
42
of the side handle
40
. Since the starter footstool
50
is disposed in this manner, the working machine
10
can be firmly fixed in place by placing one's foot on this starter footstool
50
at the time of pulling the recoil starter handle
25
, thereby facilitating the starting of the working machine
10
.
Since the starter footstool
50
extends horizontally to the vicinity of the lower end portion
30
b
of the rear coupling portion
30
B and the rear end portion
50
b
of the starter footstool
50
is integrally connected with the lower end portion
30
b
of the rear coupling portion
30
B, the side handle
40
is enabled, via the starting footstool
50
, to be connected directly with the lower end portion
30
b
of the rear coupling portion
30
B. As a result, the side handle
40
(the front grip portion
41
and the diagonal grip portion
42
) is easy to grip, irrespective of the working posture of the machine. Also, the operator of the portable power working machine
10
receives a feeling of integrity between the top and side handles
30
and
40
, thus making it possible to improve the operability of the machine
10
as compared with the conventional portable power working machine wherein the other end (lower end) of the side handle is secured to a lower edge portion of the proximal (rear) end of the main housing (recoil starter case).
Since the members mounted on the main housing
12
, such as the recoil starter case
12
A, are attached independently of the handles
30
and
40
, it is no longer required, when performing maintenance on components housed inside the main housing
12
(such as maintenance and inspection of the prime mover
70
and the recoil starter
25
), to dismount the side handle
40
from the top handle
30
, so that the maintenance work can be facilitated.
In as much as the vibration isolating member
60
is interposed between the vicinity of the front end
30
a
of the top grip portion
30
A and the top surface
12
a
of the main housing
12
, and at the same time, since the vibration isolating spring
65
is interposed between the lower end
30
b
of the rear coupling portion
30
B and a lower end portion
12
c
of the rear end portion
12
b
of the main housing
12
, the vibration of both handles
30
and
40
can be minimized, thus giving the operator a feeling of improved integrity, and making it possible to improve the operability of the working machine
10
.
While the foregoing embodiment of the present invention has been described in detail above for the purpose of illustration, it will be understood that the construction of the device can be varied without departing from the spirit and scope of the invention.
For example, although the embodiment is a chain saw, the present invention is also applicable to other kinds of portable power working machines, such as power cutters and hedge trimmers.
Further, although the top handle is formed as a separate body from the side handle in the above embodiment, they can be integrally formed.
As explained above, according to the portable power working machine of the present invention, in addition to the advantage of facilitating the starting of the engine owing to the provision of the footstool, it is now possible to easily grip the side handle irrespective of the working posture of the machine, to restrict transmission of vibrations of the main housing to the side handle, thereby giving the operator a feeling of integrity between the top and side handles and improving the operability of the machine, and to make it convenient for the operator to perform maintenance work on the components housed inside the main housing.
Claims
- 1. A portable power working machine, comprising:(a) a main housing having a front end portion; (b) a working member projecting forwardly from the front end portion of the main housing; (c) a prime mover housed in the main housing; (d) a top handle of L-shape in side elevation and including a top grip portion located above and extending over and parallel to a top surface of the main housing and extending in a longitudinal direction of the main housing, a rear coupling portion extending from the top grip portion along a rear side of the main housing, a front end of the top grip portion being connected with a front end portion of the top surface of the main housing, and the rear coupling portion being coupled with a rear end portion of the main housing; (e) a side handle having a front grip portion which extends horizontally and laterally from the vicinity of the front end of the top grip portion, and a diagonal grip portion which curves out and down from the front grip portion and extends diagonally straight as viewed in side elevation toward the lower end of the rear coupling portion of the top handle; and (f) a starting footstool formed contiguously to a lower end of the diagonal grip portion and extending horizontally to the vicinity of the lower end portion of the rear coupling portion of the top handle; wherein one end portion of the front grip portion of the side handle is connected directly to or molded integrally with the top grip portion of the top handle at a location close to the front end thereof, and a rear end portion of the starting footstool is connected directly or molded integrally with the rear coupling portion of the top handle at a location close to the lower end thereof.
- 2. The portable power working machine according to claim 1, wherein the starting footstool is molded integrally with the side handle.
- 3. The portable power working machine according to claim 1, wherein said one end portion of the front grip portion of the side handle is connected directly to the top grip portion of the top handle by a bolt, and said rear end portion of the starting footstool is connected directly to the rear coupling portion of the top handle by a bolt.
- 4. The portable power working machine according to claim 1, wherein the starting footstool is configured in plan such that the outer sidewall thereof converges gradually from the front end portion thereof toward the vicinity of the rear end portion thereof so as to make it gradually approach the main housing.
- 5. The portable power working machine according to claim 1, wherein a vibration isolating member is interposed between the front end of the top grip portion and the top surface of the main housing.
- 6. The portable power working machine according to claim 1, wherein a vibration isolating member is interposed between the lower end of the rear coupling portion of the top handle and a lower end portion of the rear end portion of the main housing.
- 7. The portable power working machine according to claim 1, wherein the diagonal grip portion of the side handle has an oval cross section whose inner circumference has a larger radius of curvature than that of the outer circumference thereof.
- 8. The portable power working machine according to claim 1, wherein the working member is a chain saw set having a guide bar attached to the main housing, and a saw chain trained around the guide bar.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-018590 |
Jan 2000 |
JP |
|
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5029561 |
Koga |
Jul 1991 |
A |
5570512 |
Hoppner |
Nov 1996 |
A |
Foreign Referenced Citations (1)
Number |
Date |
Country |
2-150201 |
Dec 1990 |
JP |