This application claims priority from Japanese Patent Application No. 2010-294443 filed Dec. 29, 2010. The entire content of this priority application is incorporated herein by reference.
The present invention relates to a handgrip for holding a portable working tool, such as a brushcutter.
One type of conventional handgrip for a portable working tool well-known in the art is configured of a rigid resin member (a plastic, for example) and an elastic material covering the resin member (elastomer, for example) in order to improve operator's sense of gripping at the time of performing cutting work as well as to suppress transmission of vibration during the cutting work. Japanese Patent Application Publication No. H11-253025 discloses one of such handgrip in which either a plastic assembly alone or a plastic assembly coated with an elastomer material constitutes the handgrip to which a switch box is fixed by screwing.
However, in the above-identified handgrip, a plurality of plastic components needs to be screwed together to form the plastic assembly, and the elastomer material further needs to be applied to the plastic assembly. Therefore, an increased number of components are required, and a manufacturing process inevitably becomes complex.
In view of the foregoing, it is an object of the present invention to provide a handgrip for a portable working tool capable of being manufactured with a smaller number of components, with reduced production costs, and in a simpler manufacturing process.
In order to attain the above and other objects, the present invention provides a grip provided around a hollow handle pipe of a portable working tool. The grip includes: a switch unit configured to control operation of the portable working tool; a grip portion for enabling an operator to hold the portable working tool; a pipe insertion portion; and a switch mounting portion. The grip portion extends in an extending direction and has one end and another end opposite to the one end. The pipe insertion portion is formed at the one end of the grip portion and is formed with a pipe insertion hole from which the handle pipe is inserted. The switch mounting portion is formed at the another end of the grip portion and is formed with a switch mounting hole in which the switch unit is mounted. The grip portion, the pipe insertion portion and the switch mounting portion is integrally formed of an elastic material.
Preferably, the grip portion is formed with a through-hole extending in the extending direction, the pipe insertion hole and the switch mounting hole being in fluid communication with each other via the through-hole, the handle pipe being inserted into the through-hole from the pipe insertion hole.
Preferably, the switch mounting hole has a bottom surface with which the switch unit is in abutment when the switch unit is mounted, and the through-hole has an end surface with which the handle pipe is in abutment when the handle pipe is inserted, the bottom surface and the end surface are positioned adjacent to each other in the extending direction.
Preferably, the switch unit includes terminals connected to a drive source for driving the portable working tool, the terminals being positioned within an inner space of the hollow handle pipe for positioning the switch unit relative to the grip portion.
Preferably, the switch mounting hole has an inner peripheral surface on which a recessed portion is formed, and the switch unit has a projection configured to be engaged with the recessed portion when the switch unit has been mounted in the switch mounting hole.
Preferably, the pipe insertion hole has a first axis extending in the extending direction and the switch mounting hole has a second axis extending in a direction intersecting the first axis.
Preferably, the second axis is slanted relative to the first axis by an angle of 10 degrees.
Preferably, the grip portion includes a first portion and a second portion, the first portion being brought into contact with an operator's palm and the second portion being brought into contact with operator's fingers when the operator grips the grip portion, and the second axis being slanted relative to the first axis toward the first portion of the grip portion.
Preferably, the switch mounting portion further includes a first protruding portion and the pipe insertion portion further includes a second protruding portion, the second portion being positioned between the first and second protruding portions in the extending direction, the first and second protruding portions gradually protruding outward in a direction perpendicular to the extending direction.
Preferably, the switch mounting portion further includes a surrounding portion disposed around the switch mounting hole, the surrounding portion partially surrounding the switch unit and protrudes outward than the switch unit mounted in the switch mounting hole in the extending direction.
According to another aspect, the present invention provides a portable working tool. The working tool includes a drive source for driving the portable working tool, a hollow handle pipe and a grip provided around the hollow handle pipe. The grip includes: a switch unit configured to control driving of the drive source; a grip portion for enabling an operator to hold the portable working tool; a pipe insertion portion and a switch mounting portion. The grip portion extends in an extending direction and has one end and another end opposite to the one end. The pipe insertion portion is formed at the one end of the grip portion and is formed with a pipe insertion hole from which the handle pipe is inserted. The switch mounting portion is formed at the another end of the grip portion and is formed with a switch mounting hole in which the switch unit is mounted. The grip portion, the pipe insertion portion and the switch mounting portion are integrally formed of an elastic material.
With this configuration, since the grip portion, the pipe insertion portion and the switch mounting portion are all integrally formed of an elastic material, the grip can be manufactured with a reduced number of parts, with lower production costs, and in a simpler manufacturing process. Further, the grip according to the embodiment is configured solely of an elastic material (elastomer), without necessitating many complementary parts. Therefore, the operator does not feel a sense of discomfort at the time of gripping since there is no parting face line of the complementary parts nor any screw seat, and cutting work can be done with improved workability.
In the drawings:
First, a general construction of a brushcutter 101 as an example of a portable working tool according to an embodiment of the invention will be described while referring to
The brushcutter 101 mainly includes a pipe section 2, a rotary cutting blade 3, a driving section 5 and a handle pipe 20, as shown in
The handle pipe 20 is a U-shaped hollow pipe, and is made from an aluminum alloy. The handle pipe 20 is assembled to the pipe section 2 via an attachment section 23 at a position adjacent to a longitudinal center of the pipe section 2 but closer to the driving section 5 than to the rotary cutting blade 3. When viewed from the driving section 5, the handle pipe 20 has a right end portion 21 on which a handgrip 10 is provided and a left end portion 22 on which a handgrip 7 is mounted. With this configuration, an operator can firmly grip the handgrips 7, 10 with his hands when holding the brushcutter 101.
On the right end portion 21 of the handle pipe 20, a throttle lever 6 is disposed below the handgrip 10 for enabling the operator to adjust a rotational speed of the engine 1. The throttle lever 6 is shown in
Next, a detailed configuration of the handgrip 10 according to the embodiment of the present invention will be described with reference to
The handgrip 10 is configured of a grip member 100 and a switch unit 30 including the switch 31, as shown in
The grip member 100 is integrally made from an elastic material, such as rubber and elastomer. The grip member 100 has a substantially cylindrical shape. Hereinafter, a direction in which the grip member 100 extends will be referred to as an extending direction. The grip member 100 has a longitudinal central portion 11 protruding radially outward for facilitating operator's gripping the handgrip 10, as shown in
The grip portion 11 is formed with a cylindrical-shaped through-hole 15 penetrating through the grip portion 11 in the extending direction. The grip portion 11 and the through-hole 15 share an axis A in the extending direction, as show in
The grip member 100 has an upper end portion on which a switch installation hole 15b is formed and a lower end portion on which a handle pipe insertion hole 15a is formed in the extending direction, as shown in
The handle pipe insertion hole 15a and the switch installation hole 15b are respectively in fluid communication with the through-hole 15. The handle pipe insertion hole 15a is concentrically arranged with the through-hole 15 (the handle pipe insertion hole 15a and the through-hole 15 share the axis A). The switch installation hole 15b has an axis B that is slanted relative to the axis A by an angle of about 10 degrees such that the switch 31, which is mounted in the switch installation hole 15b, is oriented diagonally downward toward the palm-side grip portion 11a, as shown in
The switch unit 30 is inserted in and fitted with the switch installation hole 15b. The switch unit 30 is a well-known switch provided with the switch 31 (a seesaw switch) and terminals 33a, 33b. When the operator manipulates the switch 31, wirings (not shown) extending from the terminals 33a, 33b are configured to be connected to/disconnected from an ignition coil (not shown) of the engine 1 such that power supply to the ignition coil (ignition plug) is either shut down or realized.
As shown in
The through-hole 15 is formed to have an inner diameter substantially equal to or slightly smaller than an outer diameter of the handle pipe 20. The handle pipe insertion hole 15a has an inner diameter slightly greater than that of the through-hole 15 for facilitating initial insertion of the handle pipe 20, as shown in
As shown in
As shown in
The upper end portion of the grip member 100 serving as the claimed switch mounting portion further includes a surrounding portion 14 and a projecting portion 19. The surrounding portion 14 is positioned at the finger-side grip portion 11b side relative to the switch installation hole 15b, while the projecting portion 19 is positioned at the palm-side grip portion 11a side relative to the switch installation hole 15b. More specifically, as shown in
As described above, according to the brushcutter 101 of the present embodiment, the grip member 100 of the handgrip 10 is solely and integrally made from an elastomer or a rubber. Compared to a conventional handgrip in which a plurality of plastic parts needs to be screwed together and coated by an elastic material, no screws are necessary for manufacturing the grip member 100. As a result, a reduced number of complementary parts and a smaller number of molded products are required, leading to a reduction in production costs. Further, this construction can also serve to mitigate operator's sense of discomfort resulting from operator's contact with screws, parting face lines (matching surfaces) of parts.
Further, the switch unit 30 can be easily fitted in the switch installation hole 15b of the grip member 100 by simply inserting and pushing the switch unit 30 into the switch installation hole 15b. And the switch unit 30 can be securely fixed to the switch installation hole 15b due to the engagement between the projecting portion 32 of switch unit 30 and the recessed portion 17 of the switch installation hole 15b. Therefore, improved productivity of the handgrip 10 can be achieved.
Further, according to the handgrip 10 of the embodiment, even though the switch unit 30 is directly mounted in the elastic grip member 100, the handle pipe 20 inserted into the grip member 100 is utilized for stably positioning the switch unit 30. That is, the inner space within the handle pipe 20 is used for stably supporting the switch unit 30 within the grip member 100. Therefore, the switch unit 30 can be prevented from sinking into and being embedded within the elastic grip member 100 even when the operator pushes the switch 31 to operate the same. User's operability of the handgrip 10 is thus enhanced. Further, since the axis B of the switch unit 30 is arranged to be slanted relative to the axis A of the grip member 100, the operator can smoothly operate the switch 31 while holding the grip member 100, thereby improving operability of the handgrip 10.
Further, due to the provision of the gently-sloped protruding portions 12, 13 interposing the finger-side grip portion 11b in the extending direction, the operator can comfortably grip the handgrip 10 while enjoying the enlarged range of movement of his fingers. With this configuration, enhanced operability can be obtained.
Further, according to the handgrip 10 of the embodiment, the switch unit 30 is partially surrounded by the surrounding portion 14 protruding outward than the switch unit 30 in the extending direction. With this configuration, regardless of what kind of posture the brushcutter 101 may take, the switch 31 cannot be pressed carelessly and easily. For example, when the rotary cutting blade 3 is being replaced, the switch 31 can be prevented from being in contact with the ground and suppressed from being operated at an unexpected timing. Further, since the switch unit 30 is arranged to be slanted relative to the axis A of the grip member 100 such that the switch 31 is oriented toward the operator, the operator can operate the switch 31 smoothly without being disturbed by the existence of the surrounding portion 14.
While the invention has been described in detail with reference to the embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention.
For example, in the embodiment, the present invention is applied to the brushcutter 1 provided with the pipe section 2, the driving section 5 and the rotary cutting blade 3. However, the present invention may also be applicable to a back pack brushcutter, and a power tool other than the brushcutter equipped with handgrips on a pipe section, such as a pole saw and a cultivator.
Number | Date | Country | Kind |
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2010-294443 | Dec 2010 | JP | national |