-
The present invention relates to a throttle lever of a
working machine incorporating a multi-purpose engine, for
example a tiller, mower, tea leaf picker, cargo carrier, rice
planting machine, harvester, binder, combine harvester,
snowplow, atomizer, pump, etc., in order to control the engine
revolution thereof. More particularly, the present invention
relates to a throttle lever with an engine stop switch provided
inside or outside the throttle lever, so that an operator may
hold a handle of working machine with his finger being placed
on a lever member of the throttle lever, and in case of emergency,
the lever member can be rotated or moved, thereby the engine
can be stopped immediately.
-
As an example of working machine relating to the present
invention, a tiller has a pair of handle bars elongated from
the main body of the tiller, and one of the pair of handle bars
has a so-called throttle lever. An operator may rotate a lever
member of the throttle lever in a proper direction according
to working condition, thereby the fuel supply to the engine
can be controlled, and accordingly the engine revolution speed
may be accelerated or decelerated in order to carry out the
working.
-
In this connection, while the operator drives the tiller,
and for example, when the operator changes the moving direction
of tiller from the forward direction to the rearward direction,
there may be a case that the handle bars held by the operator
suddenly rise due to several factors such as the reaction force
against the revolution force, the shift of gravity center to
the front of the tiller, etc., which may result in the state
that the operator is unable to operate the tiller appropriately.
This unable state of operation has resulted in a serious
accident in many cases, for example, tilling blades of the
tiller moving in the rearward direction harmed the operator,
or the tiller lost its balance and fell on the ground during
operating thereof, then the operator was caught in the tiller.
Especially, the aged operators have been increasing in recent
years, and the above mentioned accidental cases are rapidly
increasing.
-
Accordingly, for the purpose of avoiding such a dangerous
state, there have been provided an engine stop switch in order
to stop the engine immediately in case of emergency. This type
of engine stop switch in the prior art, for example a push button
switch or rotation (dial type) switch, is provided apart from
the throttle lever, such as at the center of any handle bar,
or on the handle bar in the vicinity of a handle grip. In
particular, there have been a prior art that a one-touch type
push button switch is provided on a connecting part of the left
handle bar and the right handle bar (that is, at the center
of the both handle bars).
-
Further, in regard to other working machine such as a
mower, there may be a case that the engine should be stopped
immediately. To be discussed in detail, the mower will be used
in the grassland, where industrial wastes incorporating stone
or metal might be left. If the cutter blade of the mower touches
the industrial waste incorporating stone or metal, the
revolving blade might be affected by the remarkable revolution
resistance, which might spoil the safety of working. In
addition, there may also be the case that, for example, a metal
pole of a guardrail (crash barrier) exists in the grassland,
and if the cutter blade touches the metal pole, the same
dangerous state as above discussed may occur. In such a case,
the engine should be stopped immediately in order to avoid the
danger, thus the same type of engine stop switch as the case
of tiller has been provided on the mower.
-
However, the prior art has the following disadvantageous
point.
-
According to the prior art as above discussed, in order
to avoid the danger, the engine stop switch serving to stop
the engine immediately is separately provided other than the
throttle lever. However, in ordinary case, while the operator
drives the tiller, the pair of handle bars of the tiller are
held by the both hands of the operator, in a state that any
finger of one hand of the operator is placed on the lever member
of the throttle lever in order to control the engine revolution
speed. Consequently, under several operation conditions, it
becomes very difficult for the operator to further operate the
engine stop switch, and in several cases, although the engine
should be stopped immediately, there has been a possibility
that the immediate engine stop will not be made. This also
applies to the case of mower.
-
Further, according to the structure of the prior art,
the engine stop switch provided apart from the throttle lever
stops the engine by short-circuit of the electric power.
However, when this type of engine stop switch is actuated, the
lever member of the throttle lever is maintained as the
operating position, that is, the position at which the fuel
is still supplied, thus it-is difficult to stop the engine
surely and immediately. For example, during high-speed
driving of engine, if the engine is stopped by operating the
engine stop switch and thus by short-circuit of electric power,
the fuel-air mixture may excessively introduced in the cylinder
of engine. After that, when the engine should be re-started,
the combustion chamber will be in the excessive state of
fuel-air mixture, that is, so-called "wet spark plug" , in which
state the spark plug cannot be ignited and the engine cannot
be restarted.
-
In addition, there are several tractor-type mowers in
which the electric circuit of engine will be automatically
short-circuited at the same time of turning OFF the clutch
operation handle. However, according to this type of mower,
the engine will be stopped every time the clutch is disengaged,
and this has been a serious problem to the practical operation.
-
Based on the problems as above discussed, it is an objet
of the present invention to provide a throttle lever which can
immediately stop the engine in case of emergency in order to
avoid danger, and which can also restart the engine immediately
when the engine should be restarted.
-
To achieve the object mentioned above, according to claim
1 of the present invention, there is provided a working machine
throttle lever to be attached to and detached from a working
machine comprising a main body, a lever member rotatively
attached to the main body and connected to a wire elongated
from an engine of the working machine, and an engine stop switch.
When the lever member is rotated in one direction, a revolution
speed of the engine of the working machine is accelerated, and
when the lever member is rotated in another direction, the
revolution speed of the engine of the working machine is
decelerated. Further, when the lever member is rotated by more
than a predetermined amount in any of the one and another
directions, the engine stop switch is actuated and the engine
is stopped.
-
According to claim 2 of the present invention in regard
to the working machine throttle lever of claim 1, the throttle
lever is attached to a handle bar elongated from a main unit
of the working machine in a state that the throttle lever may
be attached to and detached from the handle bar.
-
According to claim 3 of the present invention, in regard
to the working machine throttle lever of claim 1, the throttle
lever is attached to a main unit of the working machine in a
state that the throttle lever may be attached to and detached
from the main unit.
-
According to claim 4 of the present invention, in regard
to the working machine throttle lever of claim 1, the engine
stop switch is incorporated inside the throttle lever.
-
According to claim 5 of the present invention, in regard
to the working machine throttle lever of claim 1, the engine
stop switch is provided outside the throttle lever.
-
According to claim 6 of the present invention, in regard
to the working machine throttle lever of claim 4, there are
further provided a main body switch element incorporated in
the main body and a lever member switch element incorporated
in the lever member. When the lever member is rotated by more
than a predetermined amount in the one or another direction,
the engine is stopped by short-circuiting both of the switch
elements.
-
According to claim 7 of the present invention, in regard
to the working machine throttle lever of claim 4, the engine
stop switch comprises a main body switch element of which
position on the main body has been determined and is fit into
the main body, and a lever member switch element of which
position on the lever member has been determined and is fit
into the lever member. When the lever member is rotated by
more than a predetermined amount in the one or another direction,
the main body switch element and the lever member switch element
of the engine stop switch becomes a predetermined position
relation so that the engine stop switch is actuated and the
engine is stopped.
-
According to claim 8 of the present invention, in regard
to the working machine throttle lever of claim 7, there are
further provided protrusion on any one of the main body switch
element and the main body and hollow on the other of the main
body switch element and the main body so that a position of
the main body switch element is determined by engagement of
the protrusion with the hollow, and protrusion on any one of
the lever member switch element and the lever member and hollow
on the other of the lever member switch element and the lever
member so that a position of the lever member switch element
is determined by engagement of the protrusion with the hollow.
-
According to claim 9 of the present invention, in regard
to the working machine throttle lever of claim 4, the main body
switch element is integrally incorporated in the main body by
insertion method during manufacturing of the main body, and
the lever member switch element is integrally incorporated in
the lever member by insertion method during manufacturing of
the lever member.
-
According to claim 10 of the present invention, in regard
to the working machine throttle lever of claim 5, there are
further provided a lever member switch element outside the
lever element and the other switch element outside a main unit
of the working machine or a handle bar. When the lever member
is rotated by more than a predetermined amount in the one or
another direction, the engine is stopped by short-circuiting
both of the switch elements.
-
According to claim 11 of the present invention, in regard
to the working machine throttle lever of claim 5, the engine
stop switch is attached on the lever member, and engine is
stopped when the lever member is rotated by more than a
predetermined amount as the engine stop switch becomes in
contact with a main unit of the working machine.
-
According to claim 12 of the present invention, in regard
to the working machine throttle lever of claim 1, there is
further provided an idle mechanism attached to the throttle
lever. An operator may confirm by feeling of resistance
whether or not the lever member reaches just before a position
at which the engine can be stopped, then the operator may
further rotate the lever member in order to stop the engine.
-
According to claim 13 of the present invention, in regard
to the working machine throttle lever of claim 12, the idle
mechanism is incorporated in a space between the lever member
and the main body. When an operator actuates the engine stop
switch by rotating the lever member, a resistance force is given
to the operator just before the engine stop switch is actuated,
then the operator may further rotate the lever member in order
to actuate the engine stop switch.
-
According to claim 14 of the present invention, in regard
to the working machine throttle lever of claim 1, when the lever
member is rotated by more than a predetermined amount in one
direction, or when the lever member is rotated by more than
the predetermined amount in another direction, the engine is
stopped regardless of direction of rotation.
-
According to claim 15 of the present invention, in regard
to the working machine throttle lever of claim 1, an attachment
position of the lever member switch element or the main body
switch element is adjustable, thereby a timing of engine stop
is adjusted.
-
According to claim 16 of the present invention, in regard
to the working machine throttle lever of claim 1, an operation
part of the lever member is formed in a forked shape.
-
According to claim 17 of the present invention, in regard
to the working machine throttle lever of claim 1, the fuel
supply is cut when the lever member is rotated by more than
a predetermined amount, and an engine electric power circuit
is short-circuited at the same time.
-
According to claim 18 of the present invention, in regard
to the working machine throttle lever of claim 1, there is
further provided a waterproofing means covering the engine stop
switch.
-
According to claim 19 of the present invention, in regard
to the working machine throttle lever of claim 1, a metal
fitting in order to attach the throttle lever to the working
machine is attached to or detached from the throttle lever from
the outside of the throttle lever.
-
According to claim 20 of the present invention, in regard
to the working machine throttle lever of claim 1, a force is
always applied by an elastic member to the throttle lever in
a direction of decelerating a revolution speed of the engine.
-
Consequently, the engine stop switch in order to stop
the engine immediately is provided outside or inside the
throttle lever, and when the lever member of the throttle lever
is rotated by more than a predetermined amount in one or another
direction, the engine stop switch is actuated in case of
emergency, thus the engine can be stopped. Therefore, in a
normal operation, the fingers of the operator are always placed
on the lever member of the throttle lever in order to carry
out the working by controlling the revolution speed of the
engine, the rotation of the lever member by these fingers in
case of emergency can be accomplished easily. Accordingly,
in case of emergency, the operator may rotate the lever member
of the throttle lever by more than a predetermined amount in
one or another direction without being confused, thus the
engine can be stopped immediately.
-
Preferably, the throttle lever may be attached to a
handle bar elongated from a main unit of the working machine.
-
Preferably, the throttle lever may be attached to a main
unit of the working machine.
-
In regard to the attachment of engine stop switch to the
throttle lever, the engine stop switch may be incorporated
inside, or provided outside, the throttle lever.
-
When the engine stop switch is incorporated inside the
throttle lever, there may be further provided a main body switch
element incorporated in the main body and a lever member switch
element incorporated in the lever member. When the lever
member is rotated by more than a predetermined amount in the
one or another direction, the engine is stopped by short-circuiting
both of the switch elements.
-
When the engine stop switch is incorporated inside the
throttle lever, the engine stop switch may comprise a main body
switch element of which position on the main body has been
determined and is fit into the main body, and a lever member
switch element of which position on the lever member has been
determined and is fit into the lever member. When the lever
member is rotated by more than a predetermined amount in the
one or another direction, the main body switch element and the
lever member switch element of the engine stop switch become
a predetermined position relation so that the engine stop
switch is actuated and the engine is stopped.
-
Preferably, as an example of the engagement mechanism
described above, there may be provided protrusion on any one
of the main body switch element and the main body and hollow
on the other of the main body switch element and the main body
so that a position of the main body switch element is determined
by engagement of the protrusion with the hollow, and also
protrusion on any one of the lever member switch element and
the lever member and hollow on the other of the lever member
switch element and the lever member so that a position of the
lever member switch element is determined by engagement of the
protrusion with the hollow.
-
Preferably, when the engine stop switch is incorporated
inside the throttle lever, the main body switch element may
be integrally incorporated in the main body by insertion method
during manufacturing of the main body, and the lever member
switch element may be integrally incorporated in the lever
member by insertion method during manufacturing of the lever
member.
-
On the other hand, when the engine stop switch is provided
outside the throttle lever, there may be provided a lever member
switch element outside the lever element and the other switch
element outside a main unit of the working machine or a handle
bar. When the lever member is rotated by more than a
predetermined amount in the one or another direction, the both
of the switch elements become in contact with each other, thus
the engine is stopped by short-circuiting both of the switch
elements.
-
Preferably, the engine stop switch may be attached on
the lever member, and engine is stopped when the lever member
is rotated by more than a predetermined amount as the engine
stop switch becomes in contact with a main unit of the working
machine.
-
Preferably, there may be provided an idle mechanism
attached to the throttle lever. An operator may confirm by
feeling of resistance whether or not the lever member reaches
just before a position at which the engine can be stopped, then
the operator may further rotate the lever member in order to
stop the engine.
-
Preferably, when the idle mechanism is provided, the idle
mechanism may be provided in a space between the lever member
and the main body. When an operator actuates the engine stop
switch by rotating the lever member, a resistance force is given
to the operator just before the engine stop switch is actuated,
then the operator may further rotate the lever member in order
to actuate the engine stop switch.
-
Preferably, the engine may be stopped when the lever
member is rotated by more than a predetermined amount in one
direction, or when the lever member is rotated by more than
the predetermined amount in another direction, regardless of
direction of rotation.
-
Preferably, an attachment position of the lever member
switch element or the main body switch element may be adjustable,
thereby a timing of engine stop can be adjusted.
Preferably, an operation part of the lever member may
be formed in a forked shape.
-
Preferably, the fuel supply may be cut when the lever
member is rotated by more than a predetermined amount, and an
engine electric power circuit may be short-circuited at the
same time.
-
Preferably, there may be a waterproofing means covering
the engine stop switch.
-
Preferably, a metal fitting in order to attach the
throttle lever to the working machine may be attached to or
detached from the throttle lever from the outside of the
throttle lever.
-
Preferably, a force may always be applied by an elastic
member to the throttle lever in a direction of decelerating
a revolution speed of the engine.
-
With this structure, as compared with the prior art in
which the engine stop switch is provided separate from the
throttle lever, more effective operation can be accomplished,
thus the safety may improve as well. In case of emergency,
according to the prior art, the operator may feel danger to
himself and be confused, thereby the appropriate action in
order to avoid the danger cannot be performed, which would
result in a serious accident. On the other hand, according
to the present invention, such a danger may surely be avoided,
and the higher safety can be obtained.
-
When the engine stop switch is incorporated inside the
throttle lever, since the structural member of the engine stop
switch will not be exposed to the outside of the throttle lever,
the function of the engine stop switch will not be spoiled due
to intervention of other parts, and the malfunction of the
engine stop switch can also be prevented. Further, the engine
stop switch will not spoil the aesthetic of the throttle lever.
-
When the engine may be stopped regardless of direction
of the rotation of the throttle lever, further effective
operation and higher safety can be obtained.
-
With this structure, in particular, since the engine stop
switch comprises, a main body switch element of which position
on the main body has been determined and is fit into the main
body, and a lever member switch element of which position on
the lever member has been determined and is fit into the lever
member, the position of each switch element can be determined
easily and accurately, thus the more precision engine stop
switch can be obtained.
-
Further, since the lever member switch element and the
main body switch element are assembled according to the
hollow-protrusion structure engaged with each other, the
assemble thereof can be made by accurately determining the
engagement position.
-
Further, when the engine stop timing is adjustable, the
desired stop timing corresponding to various working machines
can be obtained.
-
Further, when an operation part of the lever member is
formed in a forked shape, further facile operation during
emergency stop of the engine can be accomplished.
-
Further, when a waterproofing means covering the engine
stop switch is provided, high durability can be obtained for
a long period.
-
Further, when a metal fitting in order to attach the
throttle lever to the working machine may be attached to or
detached from the throttle lever from the outside of the
throttle lever, the attachment or detachment of the throttle
lever can be made easily.
-
Further, when a force is always be applied by an elastic
member to the throttle lever in a direction of decelerating
a revolution speed of the engine, the position of the lever
member may become just before the engine stop automatically
by simply release the finger grip of the operator.
-
Further, when the idle mechanism is provided at a space
between the lever member and the main body, the desired idle
function may be obtained without requiring the complicated
structure outside the throttle lever. When the idle mechanism
is incorporated inside the throttle lever, the malfunction of
the engine stop switch may also be prevented (if the idle
mechanism is provided outside the throttle lever, debris may
be caught in the idle mechanism, thereby the idle mechanism
cannot be operated, or malfunction thereof will occur).
-
The invention will be described below in detail with
reference to the accompanying drawings, in which:
- Figure 1 is a side view showing an overall structure of
a tiller according to a first embodiment of the present
invention;
- Figure 2 is a perspective view showing a structure of
a grip of the left handle bar of the tiller and a throttle lever
provided adjacent to the grip according to the first embodiment
of the present invention;
- Figure 3 is a perspective view showing the structure of
the grip of the left handle bar of the tiller and the throttle
lever provided adjacent to the grip, also explaining a state
that the throttle lever is rotated in the direction of
accelerating of engine revolution speed according to the first
embodiment of the present invention;
- Figure 4 is a perspective view showing the structure of
the grip of the left handle bar of the tiller and the throttle
lever provided adjacent to the grip, also explaining a state
that the throttle lever is rotated in the direction of
decelerating of engine revolution speed according to the first
embodiment of the present invention;
- Figure 5 is a perspective view showing an external
appearance of the throttle lever according to the first
embodiment of the present invention;
- Figure 6 is a perspective view showing an external
appearance of the throttle lever according to the first
embodiment of the present invention;
- Figure 7 is a plan view showing a structure of an end
member of the throttle lever according to the first embodiment
of the present invention;
- Figure 8 is a plan view showing a structure of a leaf
spring member of the throttle lever according to the first
embodiment of the present invention;
- Figure 9 is a plan view showing a structure of a lever
member of the throttle lever according to the first embodiment
of the present invention;
- Figure 10 is a plan view showing a structure of a lever
member switch element of the throttle lever according to the
first embodiment of the present invention;
- Figure 11 is a plan view showing a structure of a main
body switch element of the throttle lever according to the first
embodiment of the present invention;
- Figure 12 is a plan view showing a structure of the end
member of the throttle lever according to the first embodiment
of the present invention;
- Figure 13 is an exploded front view of the throttle lever
according to the first embodiment of the present invention,
showing the order of assembly process of each part shown in
Figs. 7 through 12;
- Figure 14 is a side view showing the overall structure
of the tiller according to the first embodiment of the present
invention, also explaining a state that the tiller is tilted
toward the front due to occurrence of any trouble;
- Figure 15 is a perspective view showing the overall
structure of the tiller according to the first embodiment of
the present invention, also explaining a normal operation
state;
- Figure 16 is a perspective view showing the overall
structure of the tiller according to the first embodiment of
the present invention, also explaining a state that the tiller
is tilted toward the front due to occurrence of any trouble;
- Figure 17 is a view showing a relation between the
position of the lever member switch element and the position
of the main body switch element during normal operation
according to the first embodiment of the present invention;
- Figure 18 is a view showing a relation between the
position of the lever member switch element and the position
of the main body switch element when the engine is stopped
according to the first embodiment of the present invention;
- Figure 19 is a perspective view showing a state that an
operator carries a mower serving as a working machine according
to a second embodiment of the present invention;
- Figure 20 is a partial perspective view showing an
expanded state that the operator holds a grip of the mower by
the right and left hands of the operator according to the second
embodiment of the present invention;
- Figure 21 is a perspective view showing a state that an
operator carries a mower serving as a working machine according
to a third embodiment of the present invention;
- Figure 22 is a partial perspective view showing an
expanded state that the operator holds a grip of the mower by
the right and left hands of the operator according to the third
embodiment of the present invention;
- Figure 23 is a perspective view showing a state that an
operator carries a mower serving as a working machine according
to a fourth embodiment of the present invention;
- Figure 24 is a partial perspective view showing an
expanded state that the operator holds a grip of the mower by
the right and left hands of the operator according to the fourth
embodiment of the present invention;
- Figure 25 is a partial perspective view showing a
structure that an engine stop switch is provided outside a
throttle lever according to a fifth embodiment of the present
invention;
- Figure 26 is a perspective view showing an overall
structure of a mower according to a sixth embodiment of the
present invention;
- Figure 27 is a perspective view showing a structure of
a grip of the handle bar of the mower and a throttle lever
provided adjacent to the grip according to the sixth embodiment
of the present invention;
- Figure 28 is a plan view showing a structure of an end
member of the throttle lever according to the first embodiment
of the present invention;
- Figure 29 is a perspective view showing a structure of
a throttle lever according to the sixth embodiment of the
present invention;
- Figure 30 is a plan view showing a structure of an end
member of the throttle lever according to the sixth embodiment
of the present invention;
- Figure 31 is a plan view showing a structure of a leaf
spring member of the throttle lever according to the sixth
embodiment of the present invention;
- Figure 32 is a plan view showing a structure of a lever
member of the throttle lever according to the sixth embodiment
of the present invention;
- Figure 33 is a plan view showing a structure of a lever
member switch element of the throttle lever according to the
sixth embodiment of the present invention;
- Figure 34 is a plan view showing a structure of a main
body switch element of the throttle lever according to the sixth
embodiment of the present invention;
- Figure 35 is a plan view showing a structure of the end
member of the throttle lever according to the sixth embodiment
of the present invention;
- Figure 36 is an exploded front view of the throttle lever
according to the sixth embodiment of the present invention,
showing the order of assembly process of each part shown in
Figs. 30 through 35;
- Figure 37 is a plan view showing a relation between the
main body switch element and the end member according to the
sixth embodiment of the present invention;
- Figure 38 is a view showing a relation between the
positions of the switch elements with each other during normal
operation according to the sixth embodiment of the present
invention;
- Figure 39 is a view showing a relation between the
positions of the switch elements with each other when the engine
is stopped according to the sixth embodiment of the present
invention;
- Figure 40 is a plan view showing a relation between a
main body switch member and an end member according to a seventh
embodiment of the present invention;
- Figure 41 is a plan view showing a structure of a throttle
lever provided with an idle mechanism according to an eighth
embodiment of the present invention;
- Figure 42 is a plan view showing a structure of the
throttle lever provided with the idle mechanism according to
the eighth embodiment of the present invention;
- Figure 43 is a perspective view showing a structure of
a throttle lever provided with an idle mechanism according to
an ninth embodiment of the present invention;
- Figure 44 is a perspective view showing an overall
structure of a mower according to a tenth embodiment of the
present invention;
- Figure 45 is a side view showing an overall structure
of a tiller according to an eleventh embodiment of the present
invention;
- Figure 46 is a perspective view showing an overall
structure of an atomizer according to a twelfth embodiment of
the present invention;
- Figure 47 is a perspective view showing an overall
structure of a pump according to a thirteenth embodiment of
the present invention;
- Figure 48 is a plan view showing a structure of a lever
member and a lever member switch element according to a
fourteenth embodiment of the present invention;
- Figure 49 is a plan view showing a structure of an engine
stop switch provided outside a pump according to a fifteenth
embodiment of the present invention;
- Figure 50 is a plan view of an end member on which a main
body switch element is provided according to a sixteenth
embodiment of the present invention;
- Figure 51 is a sectional view showing a relation between
the end member on which the main body switch element is provided,
and a lever member, according to the sixteenth embodiment of
the present invention;
- Figure 52 is a sectional view showing a relation between
the end member on which the main body switch element is provided,
and the lever member, according to the sixteenth embodiment
of the present invention;
- Figure 53 is a plan view, as viewed from the outside,
of an end member on which a main body switch element is provided
according to a seventeenth embodiment of the present invention;
- Figure 54 is a sectional view cut along a line A-A of
Fig. 53 according to the seventeenth embodiment of the present
invention;
- Figure 55 is a plan view showing a state that a main body
switch element is attached to an end member according to an
eighteenth embodiment of the present invention;
- Figure 56 is a view showing a structure of attachment
of a throttle lever according to a nineteenth embodiment of
the present invention;
- Figure 57 is a view as viewed from an arrow B-B of Fig.
56 according to the nineteenth embodiment of the present
invention;
- Figure 58 is a view showing a structure of attachment
of a throttle lever according to the nineteenth embodiment of
the present invention;
- Figure 59 is a sectional view showing a state of a
throttle lever in a normal operation according to a twentieth
embodiment of the present invention; and
- Figure 60 is a sectional view showing a state of the
throttle lever when an engine is stopped according to the
twentieth embodiment of the present invention.
-
First Embodiment
-
A first embodiment of the present invention will now be
described with reference to Figures 1 through 16.
-
The first embodiment refers to an application of the
present invention to a tiller. Fig. 1 illustrates an overall
structure of a tiller according to an first embodiment of the
present invention, in which there is a main body of tiller 1
incorporating an engine 3 as well as a dynamo 5. The dynamo
generates an electric power, which is sent to the engine 3 via
an ignition cable 7 so that the fuel-air mixture in the engine
3 may be ignited.
-
There is a frame 9 at the bottom of the main body of tiller
1, and a drive shaft 11 is provided under the frame 9. A
detachable tilling part 13 is attached to the drive shaft 11.
Accordingly, the driving power of the engine 3 is transmitted
to this drive shaft 11 via an unillustrated power transmission
mechanism 4, thereby the tilling part is driven.
-
As to the power transmission mechanism 4, for example,
a pulley-belt mechanism, a chain-sprocket mechanism, a gear
group mechanism, etc., can be utilized.
-
For reference, Fig. 1 shows an example adopting the
pulley-belt mechanism, of which part is illustrated by a
virtual line.
-
As further illustrated in Fig. 1, there is a pair of
handle bars 15, 15 elongated from the main body of tiller 1.
-
For reference, although Fig. 1 shows only the handle bar
15 on the right side of the pair of handle bars 15, 15, Figs.
15 and 16 show the both handle bars 15, 15.
-
The ends of the pair of the handle bars 15, 15 are
respectively provided with grips 17, 17, and a throttle lever
19 is secured to the grip 17 of the handle bar 15 on the right
side. There is a wire 21 connected to the throttle lever 19,
and the other end of the wire 21 is connected to the engine
3. When the throttle lever 19 is rotated in an appropriate
direction, the engine revolution speed can be controlled via
the wire 21.
-
The handle bar 15 is further provided with a clutch lever
22, to which one end of a wire 24 is connected. This wire 24
is elongated along the handle bar 15, and the other end of the
wire 24 is engaged with the power transmission mechanism 4
discussed above. When the clutch lever 22 is rotated in an
appropriate direction, the power transmission is engaged or
released via the wire 24.
-
There is an engine stop switch 23 incorporated in the
throttle lever 19 so that the engine 3 can be stopped
immediately.
-
It should be noted that, although the engine stop switch
23 is expressly illustrated outside the throttle lever 19 in
Fig. 1 for the purpose of explanation, the engine stop switch
23 is in fact incorporated in the throttle lever 19.
-
The structure of the throttle lever 19 incorporating the
engine stop switch 23 will be discussed with reference to Figs.
5 through 13. Figs. 5 and 6 are perspective views showing the
external appearance of the throttle lever 19, and Figs. 7
through 12 are views showing the structural parts by exploding
the throttle lever 19. Further, Fig. 13 is a view showing the
order of assembly of these parts.
-
For reference, Figs. 1 through 4 show the throttle lever
19 only as a model for the purpose of explanation. The actual
appearance of the throttle lever 19 is as illustrated in Figs.
5 and 6, and the structural parts thereof are as illustrated
in Figs. 7 through 12.
-
The throttle lever 19 comprises, an end member 25 as
illustrated in Fig. 7, a leaf spring member 27 as illustrated
in Fig. 8, a lever member 29 as illustrated in Fig. 9, a lever
member switch element 31 (i.e. a switch element on the side
of the lever member) as illustrated in Fig. 10, a main body
switch element 33 (i.e. a switch element on the side of the
main body) as illustrated in Fig. 11, and an end member 35 as
illustrated in Fig. 12.
-
The illustration order of Figs. 7 through 12 corresponds
to the order of assembly of each structural part shown in each
drawing. That is, as illustrated in Fig. 13, the leaf spring
member 27 is placed under the end member 25, and the lever member
29 is placed under the leaf spring member 27, and the lever
member switch element 31 is placed under the lever member 29,
and the main body switch member 33 is placed under the lever
member switch element 31, and the end member 35 is placed under
the main body switch element 33. The thus assembled parts are
then fastened and fixed by a bolt 22, a washer 24 and a nut
26.
-
The head of this bolt 22 is accommodated in an
unillustrated hollow space formed in the end member 25, and
the nut 26 is also accommodated in an unillustrated hollow space
formed in the end member 35.
-
The main body of the throttle lever 19 comprises the above
discussed end member 25, the end member 35, etc., and the lever
member 29 is rotatively attached to this main body.
-
Further, as illustrated in Fig. 6, a metal fitting 37
is secured to the end member 35. The metal fitting 37 is
substantially in the shape of U, with which a grip 17 of the
handle bar 15 is engaged, and they are fastened by unillustrated
fastening bolt member and nut member. Thus the throttle lever
19 is attached and fixed to the grip 17.
-
The lever member switch element 31 and the main body
switch element 33 will now be described in detail. The lever
member switch element 31 is incorporated in the lever member
29 in a state that the rotation of the lever member switch
element 31 is prohibited. The surface (at the rear of Fig.
10) of the lever member switch element 31 is provided with
conductive members 31a, 31b at the angle of 180° . On the other
hand, the main body switch element 33 is incorporated in the
end member 35 in a state that the rotation of the main body
switch element 33 is prohibited. The surface (at the front
of Fig. 10) of the main body switch element 33 is provided with
conductive members 33a, 33b at the angle of 180 °.
Consequently, the conductive members 31a, 31b of the lever
member switch element 31 and the conductive members 33a, 33b
are incorporated facing to each other.
-
Further, as illustrated in Fig. 10, a notch 31c is formed
in the lever member switch element 31. On the other hand, a
protrusion 29a is formed on the lever member 29 to be engaged
with the above notch 31c (see Fig. 13). As the protrusion 29a
is engaged with the notch 31c, the rotation of the lever member
switch element 31 is prohibited (that is, the lever member
switch element 31 rotates together with the rotation of the
lever member 29 as a whole unit). Similarly, a notch 33c is
also formed in the main body switch element 33, and a protrusion
35a is formed on the end member 35 to be engaged with this notch
33c (see Fig. 13). As the protrusion 35a is engaged with the
notch 33c, the main body switch element 33 is attached to the
end member 35 in a state that the rotation of the main body
switch element 33 is prohibited. The conductive members 33a,
33b have lead wires 34, 36 respectively connected thereto. One
of the lead wires 34, 36 serves as the grounding cable, and
the other is connected to an electric circuit.
-
In normal operation, as illustrated in Fig. 17, the
conductive member 31a of the lever member switch element 31
and the conductive member 33a of the main body switch element
33 are electrically connected to each other, and the conductive
member 31b of the lever member switch element 31 and the
conductive member 33b of the main body switch element 33 are
also electrically connected to each other. On the other hand,
if the engine 3 should be stopped in case of emergency, the
lever member 29 is rotated by more than a predetermined amount,
thereby the lever member switch element 31 is also rotated by
the same amount simultaneously. This rotation should be
continued until the conductive members 31a, 31b of the lever
member switch element 31 straddle the conductive members 33a,
33b of the main body switch element 33, as illustrated in Fig.
18, in order to short-circuit the electric circuit.
Consequently, the engine 3 becomes the immediate stop.
-
The function of the present embodiment will now be
described on the basis of the above structure. First, in
regard to the normal operation, an operator 41 (as illustrated
in Figs. 15 and 16) holds the grips 17, 17 of the pair of handle
bars 15, 15 by the right hand 43 and the left hand 45. Then
as illustrated in Fig. 2, the throttle lever 19 becomes caught
by the fingers 43a of the right hand 43. In such a state, the
operator 41 operates the tiller by moving in the forward or
rearward direction, or by returning the tiller, with his
fingers 43a controlling the revolution speed of the engine 3
by rotating the lever member 29 of the throttle lever 19 in
an appropriate direction.
-
When the revolution speed of the engine 3 should be
accelerated, as illustrated in Fig. 3, the lever member 29 of
the throttle lever 19 is rotated downward (the state before
rotation of the lever member 19 is illustrated by actual line,
and the state after the rotation thereof is illustrated by
virtual line). On the other hand, when the revolution speed
of the engine 3 should be decelerated, as illustrated in Fig.
4, the lever member 29 of the throttle lever 19 is rotated upward
( the state before rotation of the lever member 19 is illustrated
by actual line, and the state after the rotation thereof is
illustrated by virtual line).
-
Second, if the engine 3 should be stopped immediately
due to any reason, the lever member 29 of the throttle lever
19 is rotated upward by a large amount (more than a
predetermined amount) until reaching the position as
illustrated by broken line in Fig. 4. Consequently, the
position relation of the engine stop switch 23 between the lever
member switch element 31 and the main body switch element 33
changes from the state as illustrated in Fig. 17 to that of
Fig. 18, thereby the electric circuit is short-circuited, and
the engine 3 will be stopped.
-
When the engine 3 is stopped by the above method, the
lever member 29 of the throttle lever 19 is rotated in order
to decelerate the revolution speed of the engine 3, so that
the fuel supply may be reduced. Accordingly, when the engine
3 is stopped, further to the short-circuit of the electric
circuit, the reduction of the fuel supply is also done.
-
In the present embodiment, as illustrated by virtual line
in Fig. 3, when the lever member 29 of the throttle lever 19
is rotated downward by a large amount (more than a predetermined
amount), the electric circuit can also be short-circuited.
Therefore the same function as that when the lever member 29
is rotated upward can be obtained, and the engine 3 can be
stopped immediately in the same manner.
-
After the engine 3 is stopped by the above operation,
if the lever member 29 of the throttle lever 19 is returned
by an appropriate amount before the engine 3 makes the complete
stop, the restart of the engine 3 can be accomplished.
Therefore, when the operator 41 confirms that the dangerous
state is avoided and returns the lever member 29 of the throttle
lever 19 by the appropriate amount, the previous working can
be started again easily.
-
The present embodiment has the following merits.
-
First, when the engine 3 should be stopped immediately,
it is sufficient to rotate the lever member 29 of the throttle
lever 19 in any of the appropriate directions by more than the
predetermined amount, thereby the engine stop switch 23 is
actuated and the engine 3 can be stopped immediately. At that
time, since the operator 41 holds the grips 17, 17 of the handle
bars 15, 15 by the both hands 43, 45, and since the fingers
43a of the right hand 43 are always placed on the lever member
29 of the throttle lever 19, if the engine 3 should be stopped
immediately, it is not necessary to change holding of the hands
or fingers for that purpose, and it is sufficient to only rotate
the lever member 29 of the throttle lever 19 by maintaining
the normal state that the fingers 43a are always placed.
Therefore the immediate and sure operation of stopping of the
engine 3 can be made, thereby the danger can be avoided.
-
Further, regardless of the direction of the rotation of
the lever member 29 of the throttle lever 19, the engine 3 can
be stopped immediately and surely, therefore the high level
of safety can be obtained. To be discussed in detail, the
engine 3 can also be stopped by rotating the lever member 29
by more than the predetermined amount in the direction of
accelerating the revolution speed of the engine 3.
Accordingly, for example, due to an inevitable accident, if
the tiller 1 falls down and the lever member 29 is
unintentionally rotated in the direction of accelerating the
engine revolution speed and eventually the engine 3 becomes
the exceeding high-speed revolution (over-revolution state),
the engine 3 can be stopped automatically. Consequently, the
safety obtained therefrom may become still higher.
-
In regard to the structure of the lever member switch
element 31 and the main body switch element 33, the conductive
members 31a and 31b, and 33a and 33b are respectively placed
corresponding to each other at the angle of 180° , therefore
the thickness relation of the lever member switch element 31
and the main body switch element 33 is well-balanced. That
is, for example, there is no possibility that the lever member
switch element 31 and the main body switch element 33 form a
bank and cause the malfunction.
-
Further, according to the present embodiment, when the
operator 41 tries to stop the engine 3 by rotating the lever
member 29 of the throttle lever 19 in the direction of
decelerating the revolution speed of the engine 3, that is,
in the upward direction by more than the predetermined amount,
further to the mere short-circuiting of the electric circuit,
the fuel supply is also reduced. Accordingly, the
conventional problem of so-called "wet spark plug" state when
restarting the engine can surely be prohibited.
-
After the engine 3 is stopped, if the lever member 29
of the throttle lever 19 is returned before the engine 3 makes
the complete stop, the engine 3 can be restarted easily.
Therefore, after avoiding the dangerous state, the previous
working can be started again promptly.
Second Embodiment
-
A second embodiment of the present invention will now
be described with reference to Figs. 19 and 20. Although the
first embodiment has been discussed by using the tiller as the
example of the working machine, the second embodiment will
refer to a mower as an example of the working machine.
-
Fig. 19 is a perspective view showing a state that an
operator 103 is performing a work by carrying a mower 101. The
mower 101 has a hollow shaft 105, and a rotative cutter blade
107 is attached to the top of the hollow shaft 105.
-
There is also an engine 109 attached to the basement of
the hollow shaft 105. The rotation of the engine 109 rotates
the cutter blade 107 via an unillustrated power transmission
mechanism (a centrifugal clutch, a shaft, a gear mechanism,
etc.) incorporated inside the hollow shaft 105. A grip 111
is provided at a substantial center of the hollow shaft 105,
and another grip 113 is further provided at an predetermined
position closer to the basement of the shaft than that of the
grip 111. As illustrated in Fig. 19, the operator 103 holds
the grip 111 by the left hand 103a, and also holds the grip
113 by the right hand 103b.
-
There is a throttle lever 115 provided adjacent to the
grip 113. When a lever member 115a of the throttle lever 115
is rotated in one direction, the revolution speed of the engine
109 is accelerated. When the lever member 115a is rotated in
the other direction, the revolution speed of the engine 109
is decelerated. The details thereof are as illustrated in Fig.
20. When the lever member 115a is rotated in the clockwise
direction of Fig. 20 (that is, the direction shown by an arrow
L in Fig. 20), the revolution speed of engine 109 is accelerated,
and when the lever member 115a is rotated in counterclockwise
direction of Fig. 20 (that is, the direction shown by an arrow
H in Fig. 20), the revolution speed of engine 109 is
decelerated.
-
The structure of the throttle lever 115 is essentially
the same as that of the first embodiment discussed above, in
which the engine stop switch is incorporated. Therefore, if
the engine 109 should be stopped in case of emergency, the lever
member 115a of the throttle lever 115 is rotated in the
clockwise direction of Fig. 20 (i.e. the direction of the arrow
L in Fig. 20) by more than a predetermined amount.
Consequently, the engine stop switch is actuated in order to
short-circuit the electric circuit, thus the engine 109 can
be stopped immediately.
-
In the second embodiment, likewise the case of the first
embodiment, when the lever member 115a of the throttle lever
115 is rotated in the counterclockwise direction of Fig. 20
(i.e. the direction of the arrow H in Fig. 20) by more than
a predetermined amount, the short-circuiting of the electric
circuit and the immediate stop of the engine 109 can also be
accomplished.
-
Therefore, according to the second embodiment of the
present invention, the same effect as that of the first
embodiment can be obtained.
Third Embodiment
-
A third embodiment of the present invention will now be
described with reference to Figs. 21 and 22. The third
embodiment also refers to the mower 101 as have been discussed
in the second embodiment. However, the method of holding of
the mower 101 by the operator 103 is different from that of
the second embodiment. That is, according to the second
embodiment, as illustrated in Fig. 20, the right hand 103b holds
the upper part of the grip 113 from above so that the upper
part of the grip 113 may be covered by the right hand 103b.
On the other hand, according to the third embodiment, as
illustrated in Fig. 21, the right hand 103b holds the lower
part of the grip 113 from below so that the grip 113 may be
lifted by the right hand 103b. Similarly, the left hand 103a
also holds the lower part of the grip 111 from below so that
the lower part of the grip 111 may be covered by the left hand
103a.
-
In such a state, as illustrated in Fig. 22, the index
finger 123 of the right hand 103b rotates the lever member 115a
of the throttle lever 115.
-
The other structure and function are the same as that
described in the first embodiment of the present invention,
therefore the detailed explanation thereof will not be made.
-
As above discussed, according to the third embodiment
of the present invention, the same effect as discussed in the
second embodiment of the present invention can be obtained.
Fourth Embodiment
-
A fourth embodiment of the present invention will now
be described with reference to Figs. 23 and 24. The fourth
embodiment also refers to a mower to which the present invention
is applied, likewise the case of the second and third
embodiments discussed above.
-
In regard to the mower 101 in the fourth embodiment, a
pair of handle bars 131, 133 are secured to the hollow shaft
105. The operator 103 holds the handle bar 131 by the left
hand 103a, and also holds the handle bar 133 by the right hand
103b. The throttle lever 115 is provided on the handle bar
133.
-
Fig. 24 shows an expanded state that the handle bar 133
is right hand 103b. The lever member 115a of the throttle lever
115 has protrusions 135, 137 in order to obtain more efficient
operation, that is, the rotation of lever member 115a in the
counterclockwise direction of Fig. 24 (the direction of an
arrow H in Fig. 24) can be carried out by placing the finger
of the right hand 103b on the protrusion 135, and the rotation
of the lever member 115a in the clockwise direction of Fig.
24 (the direction of an arrow L in Fig. 24) can be carried out
by placing the finger of the right hand 103b on the protrusion
137.
-
The other structure and function are the same as that
described in the second and third embodiments of the present
invention, therefore the detailed explanation thereof will not
be made.
-
As above discussed, according to the fourth embodiment
of the present invention, the same effect as discussed in the
first and second embodiments of the present invention can be
obtained.
Fifth Embodiment
-
The fifth embodiment of the present invention will now
be described with reference to Fig. 25. Although the first
through fourth embodiments refer to the structure that the
engine stop switch 23 is incorporated inside the throttle lever
19, the fifth embodiment refers to a structure that the engine
stop switch 23 is provided outside the throttle lever 19.
-
As illustrated in Fig. 25, there is a contact terminal
200a provided outside the lever member 29 of the throttle lever
19, and there is also a contact plate 200b provided on the handle
bar 15. When the engine should be stopped immediately, the
lever member 29 of the throttle lever 19 is rotated upward of
Fig. 25 by a large amount. Consequently, the contact terminal
200a becomes in contact with the contact plate 200b, thereby
the electric circuit is short-circuited, and the engine can
be stopped immediately.
-
According to the present structure that the exposed
engine stop switch 23 is provided outside the throttle lever
19, the same effect as that described in the first through
fourth embodiments of the present invention can also be
obtained.
Sixth Embodiment
-
A sixth embodiment of the present invention will now be
described with reference to Figs. 26 through 39. The sixth
embodiment also relates to the mower to which the present
invention is applied.
-
For reference, the sixth embodiment adopts another type
of throttle lever of which shape and structure are different
from those of the second embodiment.
-
Fig. 26 is a perspective view showing a state that a
operator 203 is performing a work by carrying a mower 201. The
mower 201 has a hollow shaft 205 serving as a handle bar, and
a rotative cutter blade 207 is attached to the top of the hollow
shaft 205.
-
There is also an engine 209 attached to the basement of
the hollow shaft 205. The rotation of the engine 209 rotates
the cutter blade 207 via an unillustrated power transmission
mechanism (a shaft transmitting a rotative power from the
engine 209 via a centrifugal clutch, a gear mechanism
transmitting such a rotative power to the cutter blade 207,
etc.) incorporated inside the hollow shaft 205. A grip 211
is provided at a substantial center of the hollow shaft 205,
and another grip 213 is further provided at a predetermined
position closer to the basement of the shaft than that of the
grip 211. As illustrated in Fig. 26, the operator 203 holds
the grip 211 by the left hand 203a, and also holds the grip
213 by the right hand 203b from below.
-
The method of holding of the grips in Fig. 26 is shown
only as an example, and it is clear that the grips 211 and 213
may be held by the hands from above.
-
There is a throttle lever 215 provided adjacent to the
grip 213. The throttle lever 215 is provided on the hollow
shaft 205, at a substantial upper part of Fig. 26. The state
of attachment of the throttle lever 215 is shown in detail in
Figs. 27 and 28. As illustrated in Fig. 28, one end of a wire
216 is connected to the throttle lever 215, and the other end
of the wire 216 is connected to the fuel flow controller of
the engine 209. When a lever member 229 of the throttle lever
215 is rotated in one direction, the fuel supply increases and
thereby the revolution speed of the engine 209 is accelerated.
When the lever member 229 is rotated in the other direction,
the fuel supply decreases ant thereby the revolution speed of
the engine 209 is decelerated. The details thereof are as
illustrated in Fig. 28. When the lever member 229 is rotated
in the counterclockwise direction of Fig. 28 (that is, the
direction shown by an arrow L in Fig. 28), the revolution speed
of engine 209 is accelerated, and when the lever member 229
is rotated in clockwise direction of Fig. 28 (that is, the
direction shown by an arrow H in Fig. 28), the revolution speed
of engine 209 is decelerated.
-
As illustrated in Fig. 26, there is an engine stop switch
223 incorporated in the throttle lever 215 so that the engine
209 can be stopped immediately.
-
It should be noted that, although the engine stop switch
223 is expressly illustrated outside the throttle lever 215
for the purpose of explanation, the engine stop switch 223 is
in fact incorporated in the throttle lever 215.
-
The structure of the throttle lever 215 incorporating
the engine stop switch 223 will be discussed with reference
to Figs. 28 through 39. Fig. 28 is a perspective views showing
the external appearance of the throttle lever 215, and Fig.
29 is also a perspective view showing the external appearance
of the throttle lever 215. Figs. 30 through 35 are views
showing the structural parts by exploding the throttle lever
215. Further, Fig. 36 is a view showing the order of assembly
of these parts.
-
The throttle lever 215 is provided with an end member
225, and there are indications of "High" (the direction for
accelerating the revolution speed of the engine 209) and "Low"
(the direction for decelerating the revolution speed of the
engine 209) on the surface of the end member 225. There is
a leaf spring member 227 as illustrated in Fig. 31 positioned
under the end member 225. Then, there is the lever member 229
discussed above (see Fig. 31) positioned under the leaf spring
227. There is a lever member switch element 231 as illustrated
in Fig. 33 positioned under the lever member 229.
-
The lever member switch element 231 positioned under the
lever member 229 is shown by broken line in Fig. 32.
-
Further, there is a main body switch element 233 as
illustrated in Fig. 34 positioned under the lever member switch
element 231, and there is also an end member 235 as illustrated
in Fig. 35 positioned under the main body switch element 233.
-
The illustration order of Figs. 30 through 35 corresponds
to the order of assembly of each structural part shown in each
drawing. That is, as illustrated in Fig. 36, the leaf spring
member 227 is placed under the end member 225, and the lever
member 229 is placed under the leaf spring member 227, and the
lever member switch element 231 is placed under the lever member
229, and the main body switch member 233 is placed under the
lever member switch element 231, and the end member 235 is
placed under the main body switch element 233. The thus
assembled parts are then fastened and fixed by a bolt 222, a
washer 224 and a nut 226. The head of this bolt 222 is
accommodated in an unillustrated hollow space formed in the
end member 225, and the nut 226 is also accommodated in an
unillustrated hollow space formed in the end member 235.
-
The main body of the throttle lever 215 comprises the
above discussed end member 225, the end member 235, etc., and
the lever member 229 is rotatively attached to this main body.
-
Further, as illustrated in Fig. 29, a metal fitting 237
is secured to the end member 235. The metal fitting 237 is
substantially in the shape of U, with which the hollow shaft
205 is engaged, and the hollow shaft 205 is fastened to the
metal fitting 237 by unillustrated fastening bolt member and
nut member. Thus the throttle lever 215 is attached and fixed
to the grip hollow shaft 205.
-
The lever member switch element 231 and the main body
switch element 233 will now be described in detail. The lever
member switch element 231 is incorporated in the lever member
229 in a state that the rotation of the lever member switch
element 231 is prohibited. The lever member switch element
231 has an insulator 232 made of resin, and the surface (at
the rear of Fig. 33) of the insulator 232 is provided with
conductive members 231a, 231b at the angle of 180° . In this
connection, the structure of attachment of the lever member
switch element 231 to the lever member 229 will be described.
As illustrated in Fig. 32, there is a pair of hollows 229a,
229b on the lever member 229. Further, as illustrated in Fig.
33, there is a pair of protrusions 231c, 231d on the insulator
232 of the lever member switch element 231. Accordingly, the
protrusions 231c, 231d are respectively engaged with the
hollows 229a, 229b, thereby the lever member switch element
231 is secured to the lever member 229, thus the position of
the lever member switch element 231 is determined.
-
On the other hand, the main body switch element 233 is
incorporated in the end member 235 in a state that the rotation
of the main body switch element 233 is prohibited. The main
body switch element 233 has an insulator 230 made of resin,
and the surface (at the front of Fig. 34) of the insulator 230
is provided with conductive members 233a, 233b at the angle
of 180 . Consequently, the conductive members 231a, 231b of
the lever member switch element 231 and the conductive members
233a, 233b are incorporated facing to each other.
-
Further, as illustrated in Fig. 34, there is a pair of
protrusions 230a, 230b on the rear side of the insulator 230
of the main body switch element 233 in Fig. 34. Further, as
illustrated in Fig. 35, there is a pair of hollows 235a, 235b
on the end member 235. Accordingly, the protrusions 230a, 230b
are respectively engaged with the hollows 235a, 235b, thereby
the main body switch element 233 is secured to the end member
235, thus the position of the main body switch element 233
against the end member 235 is determined.
-
The state of attachment of the main body switch element
233 to the end member 235 is as illustrated in Fig. 37.
-
The conductive members 233a, 233b have lead wires 234,
236 respectively connected thereto. One of the lead wires 234,
236 serves as the grounding cable, and the other is connected
to an electric circuit.
-
In normal operation, as illustrated in Fig. 38, the
conductive member 231a of the lever member switch element 231
and the conductive member 233a of the main body switch element
233 are in contact with each other, and the conductive member
231b of the lever member switch element 231 and the conductive
member 233b of the main body switch element 233 are also in
contact with each other. That is, the electric circuit is not
short-circuited. On the other hand, if the engine 209 should
be stopped in case of emergency, the lever member 229 is rotated
by more than a predetermined amount as illustrated in Fig. 39,
thereby the lever member switch element 231 is also rotated
by the same amount simultaneously. This rotation should be
continued until the conductive members 231a, 231b of the lever
member switch element 231 straddle the conductive members 233a,
233b of the main body switch element 233, as illustrated in
Fig. 39, in order to short-circuit the electric circuit.
Consequently, the engine 209 becomes the immediate stop.
-
The lever member 229 is in a forked shape as illustrated
in Fig. 28. That is, the operation side of the lever member
229 is provided with knobs 229a, 229b, thus the thumb of the
right hand 203b of the operator 203 may be placed on the knob
229a, and the index finger of thereof may be placed on the knob
229b.
-
The function of the present embodiment will now be
described on the basis of the above structure. First, in
regard to the normal operation, the operator 203 holds the grips
211, 213 of the hollow shaft 205 by the left hand 203a and the
right hand 203b, so that the throttle lever 215 may be operated
by the right hand 203b. In such a state, the operator 203
operates the mower with his right hand 203b controlling the
revolution speed of the engine 209 by rotating the lever member
229 of the throttle lever 215 in an appropriate direction. In
normal operation, as illustrated in Fig. 28, when the
revolution speed of the engine 209 should be accelerated, the
lever member 229 is rotated by the index finger in the direction
of H. On the other hand, when the revolution speed of the engine
209 should be decelerated, the lever member 229 is rotated by
the thumb in the direction of L.
-
Second, if the engine 209 should be stopped immediately
due to any reason, the lever member 229 of the throttle lever
215 is rotated upward by a large amount (more than a
predetermined amount) in the direction of L in Fig. 28.
Consequently, the position relation of the engine stop switch
223 between the lever member switch element 231 and the main
body switch element 233 changes from the state as illustrated
in Fig. 38 to that of Fig. 39, thereby the electric circuit
is short-circuited, and the engine 209 will be stopped. When
the engine 209 is stopped by the above method, the lever member
229 of the throttle lever 215 is rotated in order to decelerate
the revolution speed of the engine 209, so that the fuel supply
may be reduced. Accordingly, when the engine 209 is stopped,
further to the short-circuit of the electric circuit, the
reduction of the fuel supply is also done.
-
In the present embodiment, when the lever member 229 of
the throttle lever 215 is rotated by a large amount (more than
a predetermined amount) in the direction of H in Fig. 27, the
electric circuit can also be short-circuited. Therefore the
same function as that when the lever member2 29 is rotated in
the direction of L can be obtained, and the engine 209 can be
stopped immediately in the same manner.
-
After the engine 209 is stopped by the above operation,
if the lever member 229 of the throttle lever 215 is returned
by an appropriate amount before the engine 209 makes the
complete stop, the restart of the engine 209 can be accomplished.
Therefore, when the operator 203 confirms that the dangerous
state is avoided and returns the lever member 229 of the
throttle lever 215 by the appropriate amount, the previous
working can be started again easily.
-
The present embodiment has the following merits.
-
First, when the engine 209 should be stopped immediately,
it is sufficient to rotate the lever member 229 of the throttle
lever 215 in any of the appropriate directions by more than
the predetermined amount, thereby the engine stop switch 223
is actuated and the engine 209 can be stopped immediately. At
that time, since the operator 203 holds the grips 211, 213 of
the hollow shaft 205 by the both hands 203a, 203b, and since
the fingers of the right hand 203b are always placed on the
lever member 229 of the throttle lever 215, if the engine 209
should be stopped immediately, it is not necessary to change
holding of the hands or fingers for that purpose, and it is
sufficient to only rotate the lever member 229 of the throttle
lever 215 by maintaining the normal state that the fingers of
the right hand 203b are always placed. Therefore the immediate
and sure operation of stopping of the engine 209 can be made,
thereby the danger can be avoided.
-
Further, regardless of the direction of the rotation of
the lever member 229 of the throttle lever 215, the engine 209
can be stopped immediately and surely, therefore the high level
of safety can be obtained.
-
In regard to the structure of the lever member switch
element 231 and the main body switch element 233, the conductive
members 231a and 231b, and 233a and 233b are respectively placed
corresponding to each other at the angle of 180° , therefore
the thickness relation of the lever member switch element 231
and the main body switch element 233 is well-balanced. That
is, for example, there is no possibility that the lever member
switch element 231 and the main body switch element 233 form
a bank and cause the malfunction.
-
Further, according to the present embodiment, when the
operator 203 tries to stop the engine 209 by rotating the lever
member 229 of the throttle lever 215 in the direction of
decelerating the revolution speed of the engine 209, that is,
in the direction of L in Fig. 28 by more than the predetermined
amount, further to the mere'short-circuiting of the electric
circuit, the fuel supply is also reduced. Accordingly, the
conventional problem of so-called "wet spark plug" state when
restarting the engine can surely be prohibited.
-
After the engine 3 is stopped, if the lever member 229
of the throttle lever 215 is returned before the engine 209
makes the complete stop, the engine 209 can be restarted easily.
Therefore, after avoiding the dangerous state, the previous
working can be started again promptly.
-
According to the present embodiment, since the lever
member switch element 231 and the main body switch element 233
are engaged with each other by hollow-protrusion structure,
the lever member 229 and the end member 235 are fixed on the
respective positions determined by the above discussed
hollow-protrusion structure. Thus the facile assembly
thereof as well as the determination of fixing positions under
high accuracy can be accomplished.
-
Further, since the lever member 229 is in a forked shape,
the immediate stop of the engine can be carried out easily.
That is, the thumb and the index finger of the right hand 203b
of the operator 203 are always placed on the knob 229a, 229b
of the lever member 229, thus the operator 203 can operate the
throttle lever 215 promptly.
-
The lever member switch element 231 and the main body
switch element 233 are always in slidable contact with each
other under the pressing force applied to each of the switch
elements. Consequently, each of the contact surfaces is
always brushed and free from rust, thus the stable operation
condition can be obtained for a long period.
-
In the sixth embodiment of the present invention, in
regard to the lever member switch element 231, although there
is no express description of attachment of conductive members
231a, 231b to the insulator 232 made of resin, the attachment
may be made by using an adhesive. Further, when a protrusion
is provided on the insulator 232, and when hollows are provided
on the conductive members 231a, 231b, the attachment may be
made by engagement with each other.
-
The above attachment will also apply to that of main body
switch element 233.
Seventh Embodiment
-
A seventh embodiment of the present invention will now
be described with reference to Fig. 40. In the seventh
embodiment, there is a variation of structure of attachment
of the main body switch element 233 to the end member 235. That
is, the main body switch element 233 is provided with an
insulator 230 made of resin, and a pair of conductive members
233a, 233b are provided on one side of the insulator 230 (the
lower left side of the insulator 230 in Fig. 40). The
conductive members 233a, 233b are positioned on, and
penetrating in, the rim of the end member 235. The basements
of the conductive members 233a, 233b are connected to lead wires
234, 236 respectively. In regard to the insulator 230, there
is another insulator 238 provided on the insulator 230 on the
other side of the conductive members 233a, 233b. The insulator
238 serves to present the same thickness as those of the
conductive members 233a, 233b, so that the lever member switch
element 231 may not be tilted due to difference of thickness
of the lever member switch element 231 at several positions.
-
The other structure is the same as that of the sixth
embodiment of the present invention.
-
According to the seventh embodiment, since the
conductive members 233a, 233b are placed on the insulator 230
in a state that the conductive members 233a, 233b are placed
on and penetrating in the end member 235, the positions of the
conductive members 233a, 233b can be determined automatically.
Therefore, it is no longer necessary to determine the position
of the main body switch element 233 during assembly.
-
In addition, since the space between the conductive
members 233a, 233b becomes shorter than the case of the sixth
embodiment, the overall weight as well as the material cost
can be reduced.
Eighth Embodiment
-
An eighth embodiment of the present invention will now
be described with reference to Figs. 41 and 42. In the eighth
embodiment, further to the structures of the sixth and seventh
embodiments of the present invention as above discussed, there
is an idle mechanism 301 provided on the throttle lever 215.
The idle mechanism 301 comprises a leaf spring member 301a
attached to the lever member 229 of the throttle lever 215 and
a protrusion 301b protruding from the end member 225.
-
In regard to the relation of positions of the protrusion
301b and the leaf spring member 301a, when the lever member
229 is rotated in the direction of L in Fig. 42 in order to
stop the engine 209, the leaf spring member 301a becomes in
contact with the protrusion 301b and is going through over the
protrusion 301b. This state is as illustrated in Fig. 42. At
that time, the operator 203 will feel a considerable resistance
to the rotation force, and may understand that the engine 209
can be stopped immediately by rotating the throttle lever 215
over this point this resistance. Accordingly, when the
operator 203 feels this resistance, if the operator 203 further
rotates the lever member 229 upward, the engine 209 can be
stopped. Therefore, when the operator 203 feels the
resistance to the rotation force, the operator 203 may confirm
that the lever member 229 enters the area in which the engine
209 can be stopped. Thus, the operation condition will improve
remarkably.
Ninth Embodiment
-
A ninth embodiment of the present invention will now be
described with reference to Fig. 43. The ninth embodiment is
a variation of position of attachment of the idle mechanism
301 of the eighth embodiment. That is, as illustrated in Fig.
43, the leaf spring member 301a of the idle mechanism 301 is
attached to the side surface of the knob 229b of the lever member
229, and the protrusion 301b is also attached to the side
surface of the end member 235. According to the ninth
embodiment, the same function and effect as those of the eighth
embodiment can be obtained.
Tenth Embodiment
-
A tenth embodiment of the present invention will now be
described with reference to Fig. 44. In the tenth embodiment,
the present invention is applied to a different type of mower.
As illustrated in Fig. 44, a pair of handle members 412, 414
are provided on the hollow shaft 205, and the throttle lever
215 is attached to the handle member 412.
Eleventh Embodiment
-
An eleventh embodiment of the present invention will now
be described with reference to Fig. 45. The eleventh
embodiment is a variation of structure of the throttle lever
of the first embodiment. That is, the throttle lever 215
according to the sixth through tenth embodiments of the present
invention is applied to the first embodiment.
Twelfth Embodiment
-
A twelfth embodiment of the present invention will now
be described with reference to Fig. 46. The twelfth embodiment
refers to an atomizer to which the present invention is applied.
An atomizer 501 is provided with a tank 503, and is also provided
with an engine 505 under the tank 503. The throttle lever 19
according to the first embodiment as above discussed is
attached to this atomizer 501 in order to control the revolution
speed of the engine 505.
Thirteenth Embodiment
-
A thirteenth embodiment of the present invention will
now be described with reference to Fig. 47. The thirteenth
embodiment refers to a pump to which the present invention is
applied. A pump 601 is provided with an engine 603 and a pump
section 605. The throttle lever 19 incorporating the engine
stop switch 23 according to the first embodiment as above
discussed is provided on this pump 601 in order to control the
revolution speed of the engine 603 as well as to stop the engine
603 immediately.
Fourteenth Embodiment
-
A fourteenth embodiment of the present invention will
now be described with reference to Fig. 48. According to the
fourteenth embodiment, the position of the lever member switch
element 231 of the sixth embodiment as above discussed can be
adjusted.
-
For reference, Fig. 48 is a view that the lever member
switch element 231 is seen from the reverse side of Fig. 32,
that is, seen from the side of the lever member switch element
231.
-
The conductive member 231b has been formed so as to have
a hollow, and an elongated groove 701 in a shape of arc is formed
in this hollow of the conductive member 231b. This elongated
groove 701 is also formed in the insulator 230 positioned under
the conductive member 231b, and the elongated groove 701 is
fixed by a screw member 703 penetrated in the lever member 229.
When the position of the lever member switch element 231 should
be adjusted, the screw member 703 is loosened, thus the lever
member switch element 231 can be rotated within the length of
the elongated groove 701. When the desired position is
determined, the screw member 703 is fastened again.
-
Accordingly, the position of the lever member switch
element 231 can be adjusted, thereby the timing of stopping
of the engine 209 can be adjusted.
Fifteenth Embodiment
-
A fifteenth embodiment of the present invention will now
be described with reference to Fig. 49. The fifteenth
embodiment is a variation of the pump 601 of the thirteenth
embodiment to which the present invention is applied. When
the engine 603 is stopped, the lever member 29 is rotated in
the clockwise direction of Fig. 49. Consequently, a function
member 29c protruding from the lever member 29 rotates in the
direction of main body of the pump 601, thereby a contact point
801 attached to the function member 29c becomes in contact with
a resin member 803. Thus a kind of idle state is obtained.
-
When the lever member 29 is further rotated from this
idle position, the contact point 801 goes over the resin member
803, and then becomes in contact with the main body made of
metal. Accordingly, the electric circuit is short-circuited
and the engine is stopped.
Sixteenth Embodiment
-
A sixteenth embodiment of the present invention will now
be described with reference to Figs. 48, 50, 51 and 52. The
sixteenth embodiment relates to an example of waterproofing
means of the present invention. As illustrated in Fig. 50,
there is a groove 907 on the end member 235. On the other hand,
as illustrated by virtual line in Fig. 48, there is a skirt
903 protruding from the lever member 231. Thus, when the lever
member 231 is placed over the end member 235, the state as shown
in Fig. 51 is obtained. In this state, the end member 235 is
covered by the skirt 903 of the lever member 231, and since
there is the groove 907 formed on the end member 235, the
rotation of the lever member 231 is allowed. By providing this
waterproofing means, the effect of waterproofing can be
obtained.
-
In the above structure, the shape of the skirt 903 may
be thinner so as to be deformed easily, so that the skirt 903
may be in close contact with the end member 235 easily. Further,
there may be a seal 902 provided between the skirt 903 and the
end member 235, as illustrated in Fig. 52, in order to obtain
higher waterproofing effect. The seal 902 may be replaced by
a waterproof sheet. Further, the seal function may also be
obtained if the washer 24 according to the sixth embodiment,
as illustrated in Fig. 36, is made of resin.
Seventeenth Embodiment
-
A seventeenth embodiment of the present invention will
now be described with reference to Figs. 29, 53 and 54. As
has been discussed in the sixth embodiment, there is the metal
fitting 237 attached to the outside of the end member 235, and
the throttle lever 215 is attached to the hollow shaft 205 via
this metal fitting 237. In the sixth embodiment, the metal
fitting 237 is inserted from the inside of the end member 235,
thus it is impossible to detach the metal fitting 237 from the
outside.
-
Therefore, in the seventeenth embodiment, the metal
fitting 237 may be detached from the outside. As illustrated
in Fig. 53, grooves 1001, 1001 are formed on the surface of
the end member 235 facing the outside. The metal fitting 237
has a flange 237a at the end thereof, and the flange 237a is
inserted from the outside via the grooves 1001, 1001. There
are further grooves 1003, 1003 formed below the grooves 1001,
1001 in Fig. 53. The grooves 1003, 1003 are not exposed to
the outside.
-
As illustrated in Fig. 54, the flange 237a of the metal
fitting 237 is first inserted from the grooves 1001, 1001, and
then moved in the inside toward the grooves 1003, 1003, so that
the flange 237a is engaged with the grooves 1003, 1003.
Accordingly, the metal fitting 237 is attached to the end member
235. When the metal fitting 237 is detached, the procedures
in the reverse order may be applied.
-
As above discussed, since the attachment and detachment
of the metal fitting 237 can be carried out from the outside
of the end member 235, the attachment and detachment of the
throttle lever 215 (for example, change of attachment position,
change of angle, etc.) can be made easily.
Eighteenth Embodiment
-
An eighteenth embodiment of the present invention will
now be described with reference to Fig. 55. The eighteenth
embodiment relates to an example that the idle mechanism as
discussed in the eighth and ninth embodiments is incorporated
in the throttle lever. As illustrated in Fig. 55, there is
a protrusion 1005 protruding from the main body switch element
233.
-
When the lever member 229 is rotated, the lever member
229 goes over this protrusion 1005. At that time, the
resistance force occurs, thereby the operator 203 may confirm
that the present position of the lever member 229 is just before
the engine stop position. When the operator 203 further
rotates the lever member 229, the engine stop switch 223 is
actuated, and the engine 209 is stopped.
-
According to this type of idle mechanism, the structure
outside the throttle lever 215 may be simplified.
Nineteenth Embodiment
-
A nineteenth embodiment of the present invention will
now be described with reference to Figs. 56 through 58. The
nineteenth embodiment relates to an example of structure of
attachment of the throttle lever to the hollow shaft 205.
There is a metal fitting 1007, and engagement hollows 1009,
1009 are formed in the upper part of the metal fitting 1007
in Fig. 56. On the other hand, there are engagement
protrusions 1011, 1011 protruding from the throttle lever.
With this structure, the metal fitting 1007 is placed over the
hollow shaft 205, in a manner that the engagement hollows 1009,
1009 are respectively engaged with the engagement protrusions
1011, 1011. Then, by maintaining such an engagement state,
a screw member 1013 is inserted from the outside of the metal
fitting 1007 into the throttle lever, so that the metal fitting
1007 may be attached to and fixed on the throttle lever.
-
In the nineteenth embodiment, the attachment and
detachment of the metal fitting 1007 in regard to the throttle
lever from the outside can also be made easily, the attachment
and detachment of the throttle lever can be carried out easily.
-
Further, as illustrated in Fig. 58, there may be an
engagement protrusion 1015 provided at the top of the metal
fitting 1007, and there may also be an engagement hollow 1017
provided on the throttle lever.
Twentieth Embodiment
-
A twentieth embodiment of the present invention will now
be described with reference to Figs. 59 and 60. The twentieth
embodiment relates to a different type of throttle lever from
that in the first through nineteenth embodiments discussed
above, to which the present invention is applied. The throttle
lever according to the present embodiment is attached to the
lower part of the hollow shaft 205, in a state that the throttle
lever may be detached. There is a lever member 1023 attached
to a main body case 1021, in a state that the lever member 1023
may be rotated in directions of arrows L and H in Figs. 59 and
60.
-
With reference to Figs. 59 and 60, there is an engine
positioned on the right side, and there is an unillustrated
cutter blade attached to the left side.
-
There is a wire 216 of which one end is connected to the
lever member 1023. The other end of this wire 216 is connected
to the engine (not shown) positioned on the right side of Figs.
59 and 60. The lever member 1023 has a coil spring 1025 attached
thereto, and this coil spring 1025 always applies force to the
lever member 1023 in the direction of L in Figs. 59 and 60 (that
is, the direction of reducing the fuel supply in order to
decelerate the engine revolution speed). When the lever
member 1023 is rotated in the direction of H in Figs. 59 and
60 (that is, the direction of increasing the fuel supply in
order to accelerate the engine revolution speed) against the
force applied by the coil spring 1025, the engine revolution
speed may be accelerated.
-
There is an engine stop switch 1027 provided at the space
between the main body case 1021 and the lever member 1023. That
is, there is a lever member switch element 1029 at the end of
the lever member 1023, and there are also main body switch
elements 1031, 1033 on the main body case 1021. Further, an
idle plate 1035 is attached to the main body switch element
1031, and another idle plate 1037 is also attached to the main
body switch element 1033.
-
In regard to the lever member 1023, an operation part
thereof is in a forked shape, and an operation tip 1023a and
an operation tip 1023b are provided. During operation, the
four fingers of an operator other than the thumb are inserted
in the space between the operation tip 1023a and the operation
tip 1023b, and the thumb of the operator is placed on the hollow
shaft 205.
-
In the normal operation, as above discussed, the four
fingers of the operator other than the thumb are inserted in
the space between the operation tip 1023a and the operation
tip 1023b, and the thumb is placed on the hollow shaft 205.
In such a state, the lever member 1023 is rotated in an
appropriated direction, thereby the engine revolution speed
is controlled and the working is carried out. In particular,
since the coil spring 1025 always applies force to the lever
member 1023 in the direction of L, when the operator loosens
the grip force applied to the lever member 1023, the engine
revolution speed is automatically decelerated. On the other
hand, when the operator grips the lever member 1023 against
the force applied to the lever member 1023 by the coil spring
1025, the lever member 1023 is rotated in the direction of H,
thus the engine revolution speed may be accelerated.
-
Then, when the engine should be stopped immediately, the
grip force applied to the lever member 1023 is loosened.
Consequently, the lever member 1023 is rotated in the direction
of L due to the force applied thereto by the coil spring 1025,
and a state as shown in Fig. 59 will be obtained. However,
under this operation, the engine revolution speed is merely
decelerated, since the top of the lever member switch element
1029 becomes merely in contact with the idle plate 1035. Then,
the lever member 1023 is further rotated in the direction of
L. This can be performed by pressing down the operation tip
1023b by the back of the four fingers of the operator other
than the thumb. Consequently, the top of the lever member
switch element 1029 goes over the idle plate 1035, and becomes
in contact with the main body switch element 1031. Accordingly,
the electric circuit is short-circuited, and the engine is
stopped.
-
It is noted that the above operations, that is, the
operation of the release of grip force applied to the lever
member 1023, and the operation of pressing down of the operation
tip 1023b, are to be carried out sequentially.
-
The engine may also be stopped when the lever member 1023
is rotated in the opposite direction, that is, in the direction
of H. That is, the top of the lever member switch element 1029
first becomes in contact with the idle plate 1037, and when
the lever member 1023 is further rotated, the top of the lever
member switch element 1029 goes over the idle plate 103, and
then becomes in contact with the main body switch element 1033.
Accordingly, the electric circuit is short-circuited, and the
engine is stopped.
-
The present embodiment is not limited to the first
through twentieth embodiments described above.
-
Although the above embodiments have been described by
using the mower, tiller, atomizer or pump as an example of
working machine, it is clear that the embodiments can also be
applied to other working machines. For example, the present
invention may be applied to a cargo carrier, rice planting
machine, harvester, binder, combine harvester, slow plow, tea
leaf picker, etc.
-
According to the first embodiment, the engine 3 may be
stopped by rotating the throttle lever 15 in any one of the
directions. However, the engine 3 may also be stopped only
when the throttle lever 15 is rotated in one direction.
-
According to every embodiment, the lever member switch
element and the main body switch element are prepared as the
separate parts from the main body or the end members, so that
these switch elements may be incorporated therein during
assembly. However, it is also possible to integrally form the
lever member switch element and the main body switch element
in advance by so-called "insertion method", when the main body
and end members made of resin are manufactured.
-
Further, when the engine should be stopped by operation
of the throttle lever, the fuel supply may also be cut at the
same time. Consequently, as compared with the case of mere
short-circuiting of the electric circuit, the engine 9 may be
stopped without fail. In particular, according to the first
embodiment, the engine 9 can be stopped immediately by rotating
the lever member 29 by more than the predetermined amount in
the direction of decelerating the revolution speed of the
engine 9. In this connection, at the immediate engine stop,
the fuel may be supplied as little as possible, so that the
engine may be restarted promptly. Further, at the immediate
engine stop, the fuel supply may be cut. The cut of fuel supply
can be made by adjusting the connection of the wire 19 to the
engine 9, that is, by shutting a fuel supply control valve of
a carburetor of the engine 9 in order to cut the fuel supply.
The adjustment thereof can be carried out by adjusting an idling
adjustment member of the fuel supply control valve of the
carburetor.
-
Further, the part of the engine stop switch may be covered
by waterproofing means. For example, there may be provided
a waterproofing cap 701 shown by virtual line in Fig. 28, or
there may be also provided a waterproofing cap 705 shown by
virtual line in Fig. 47.