Motor vehicles – Steered by walking attendant – Handle movement controls vehicle drive
Reexamination Certificate
2001-12-20
2004-08-03
Morris, Lesley D. (Department: 3611)
Motor vehicles
Steered by walking attendant
Handle movement controls vehicle drive
C180S019200, C180S019100, C180S315000
Reexamination Certificate
active
06769501
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a walk behind working machine operated by an operator walking behind the machine and gripping a grip portion of a handle of the machine.
BACKGROUND OF THE INVENTION
One example of walk behind working machines is known from, for example, Japanese Utility Model Publication No. SHO-58-32578 entitled “A SELF-PROPELLED LAWNMOWER”. The known lawnmower is described below with reference to
FIG. 23
hereof.
When cutting a lawn
201
with the walk behind lawnmower
200
, an operator
204
shifts a clutch lever
207
in a direction as shown by an arrow from a position, shown in a phantom line, while gripping a grip
206
of a handle
205
under a condition where a cutter in a housing
203
is rotated by an engine
202
. With such an operation, a running clutch, interposed between the engine
202
and rear wheels
208
, is coupled to enable drive power of the engine
202
to be delivered to the rear wheels
208
. Rendering the lawnmower
200
to be self-propelled with the rear wheels
208
and front wheels
209
allows the cutter to cut the lawn
201
.
Normally, the running clutch used in the lawnmower employs a dog-clutch. The dog-clutch is arranged such that sliding a shifter in a case toward a worm gear causes clutch teeth of the shifter to be brought into mating engagement with worm teeth of the worm gear to assume a coupled state. Such a dog-clutch is instantaneously operated from an uncoupled state to the coupled state. For this reason, when the operator
204
shifts the clutch lever
207
in the direction as shown by the arrow from teh position shown by the phantom line while gripping the grip
206
of the handle
205
, the clutch is apt to be instantaneously brought into the coupled state to cause the lawnmower
200
to rapidly start off at an initial speed V1. When this occurs, since the operator
204
holds the grip
206
, rapid taking off of the lawnmower
200
causes the operator
204
to be pulled from the lawnmower
200
. Therefore, in order to have the walk behind lawnmower
200
to start off smoothly, the operator must start walking in synchronism with the coupling operation of the clutch.
However, if the operator
204
begins to walk at a low speed, a forward movement of the lawnmower
200
is interrupted, causing the rear wheels
208
of the lawnmower
200
to slip or causing the front wheels
209
to lift up as shown by the arrow. As a result, there are some instances where the grass
201
is caused to be laid down or to be torn off and where the cutter tends to be lifted up due to lifting up of the front wheels
209
. Thus, it is difficult to cut the grass
201
with a high quality finish using the walk behind lawnmower during the taking off period of the walk behind lawnmower
200
.
Because of the reasons described above, in order to allow the walk behind lawnmower
200
to start off in a suitable manner, it is required for the operator to predict the speed at which the lawnmower takes off, thereby requiring skilled handling of the walk behind lawnmower
200
in order to cut the grass
201
with a desired finish. For this reason, an attempt has heretofore been made with a view to providing a walk behind lawnmower, which is enabled to carry out a smooth taking off, into practical use.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a walk behind working machine which has excellent operability during a take-off operation to achieve a desired smooth take-off.
According to a first aspect of the present invention, there is provided a walk behind working machine which comprises: a machine body; a drive source mounted on the machine body; right and left drive wheels carried on a rear portion of the machine body and driven by actuation of the drive source; a running clutch provided between the right and left drive wheels and coupled to the drive source such that it allows use in a slipping phase; operating handles extending rearward from the machine body; and a grip/clutch lever mounted on the handles swingably between a forward position and a rearward position, the grip/clutch lever being connected to the running clutch via a clutch cable such that the running clutch is coupled when the grip/clutch lever is shifted to the forward position, and is uncoupled when the grip/clutch lever is shifted to the rearward position, whereby the working machine is capable of traveling in the clutch slipping phase during the course of shift of the grip/clutch lever between the forward and rearward positions.
By thus bringing the grip/clutch lever into a clutch slipping phase during its forward pushing, the walk behind working machine starts running at a low speed. In this instance, since the operator merely walks forward while applying the forward pushing force onto the grip/clutch lever, it is possible for the operator to handle the walk behind working machine in a natural motion, making it possible to have the walk behind working machine start off smoothly. For this reason, it is possible to cut grass with the walk behind working machine in a high quality finish from the start of work.
In addition, the walk behind working machine may start off at a low speed during the operator's forward pushing operation of the grip/clutch lever, allowing the operator to follow the start-off movement of the walk behind working machine in a natural motion.
Further, since the grip/clutch lever serves as both a clutch lever and a handle grip as a result of it being rendered capable of handling the machine body by gripping the grip/clutch lever, it is possible to perform a clutch operation with the grip/clutch lever gripped. Accordingly, it is possible to save troublesome steps for removing one hand from the handle grip with the clutch lever handled with the removed hand as required in the conventional working machine, with a resultant decrease in the operator's load.
In a preferred form, the grip/clutch lever includes stoppers mounted to proximal ends thereof for restricting fore and aft movements of the grip/clutch lever beyond the forward and rearward positions. The stoppers are thus separated from the grip of the grip/clutch lever during a handling operation of the grip/clutch lever, thereby avoiding interference of the operator's hand with the stoppers.
Desirably, the grip/clutch lever further includes a hold lever mounted to the handles forwardly of the grip/clutch lever so that by gripping the grip/clutch lever and the hold lever together as the grip/clutch lever is tilted or swung toward the hold lever until it comes to the forward position, the grip/clutch lever is retained at the forward position. By thus tilting the grip/clutch lever to the forward position while gripping the grip/clutch lever together with the hold lever, the grip/clutch lever is retained at the forward position. Since the grip/clutch lever is retained at the forward position by merely gripping the grip/clutch lever together with the hold lever, it is possible for the grip/clutch lever to be retained at the forward position in a further simplified manner.
The hold lever is swingable between a forward stationary position and a rearward gripping position so that when the hold lever is gripped together with the grip/clutch lever at the forward position, the hold lever is retained at the gripping position and when the hold lever is released from the gripped state, it is returned to the stationary position. Thus, since the hold lever is arranged to have the capability of tilting between the forward stationary position and the rearward gripping position, gripping the hold lever and the grip/clutch lever together causes the hold lever to be retained at the gripping position for thereby allowing the grip/clutch lever to be retained at the forward position. On the other hand, there is an instance where it is desired for the hold lever to be kept at the forward position by continuously pushing the grip/clutch lever forward without gripping the hold lever. In such a case, since the hold lever is rendered capable of returning to th
Iida Tetsuo
Ishikawa Tomoaki
Adams & Wilks
Honda Giken Kogyo Kabushiki Kaisha
Morris Lesley D.
Yeagley Daniel
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