JPH0414490Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a safety switch used in walk-behind working machines such as snow blowers.

(B) Conventional Technology In the case of walk-behind working machines such as snow blowers, it is dangerous if the operator is more than a predetermined distance away from the main body of the working machine during work. Therefore, a safety switch is provided to ensure safety by stopping the engine of the work equipment in the event of a danger.The main body of the safety switch is attached to the work equipment, and a fixed length of rope or wire leads out from the switch main body. One end of the was attached to the operator. When the operator moves away from the work equipment for a distance longer than the length of the rope, etc., the switch body attached to the work equipment via the rope etc. is driven and the engine of the work equipment is stopped. Safety is ensured.

(c) Problems to be solved by the invention However, in the case of the above-mentioned conventional safety switch, the work equipment can operate regardless of whether the operator has one end of the rope attached to his body or not, so there is no true There was a problem that the safety switch function could not be fully performed.

The present invention was developed in view of the above problems, and its purpose is to be easy to attach to the operator, easily detach from the operator in an emergency, provide high responsiveness, and contribute to improving work safety. The purpose of the present invention is to provide a safety switch for walk-behind work machines.

(d) Means for Solving the Problems In order to achieve the above object, the present invention is a device that is connected to the end of a lead cable led out from a walk-behind work machine and pivoted around a fulcrum so that it can be opened and closed. At the same time, a safety switch is constructed by providing electrode contacts that come into contact with and separate from each other on opposing surfaces of the sandwiching part of the switch body that is always biased toward the closed side,
The present invention is characterized in that the operation of the walking type working machine is stopped when these electrode contacts are in a contact state, and the walking type working machine can be operated when these electrode contacts are in a detached state.

(e) Function The safety switch can be easily installed by pinching the operator's clothes with the clipping part of the switch body.When installed, the electrode contacts are separated from each other, so the safety switch is easy to install on walk-behind work machines. It is operational and you can continue working. When the safety switch is removed by the operator in an emergency, the electrode contacts that were separated from each other come into contact with each other, so the operation of the work machine is immediately stopped with good response, and safety is ensured. Note that the operation of the work machine is conditional on the safety switch being worn by the operator, and the work machine will not operate unless the operator wears the safety switch, thereby increasing work safety.

(f) Examples Examples of the present invention will be described below based on the attached drawings.

First, the schematic structure of a snow blower equipped with a safety switch according to the present invention will be explained based on FIGS. 5 and 6. 5 is a side view of the snow remover, and FIG. 6 is a view taken in the direction of arrow A in FIG.

The snow blower main body 1 is made to travel by a pair of left and right crawler running devices 2, 2, and a casing 3 and an auger 4 are disposed in front of the main body 1, and a shooter 5 stands above the casing 3. It is set up. Moreover, a power transmission system (none of which is shown) such as an engine as a drive source and a traveling transmission is built into the main body 1, and a pipe-shaped operating handle 6 extends from the rear of the main body 1. has been done.

Incidentally, an L-shaped storage plate 8 is fixed to the center of the lower part of the operation panel 7 provided at the rear of the main body 1, and the safety switch 10 according to the present invention can be removed from the storage plate 8. Stored freely. The safety switch 10 is connected to the end of a lead cable 11 led out from the snow blower main body 1.
It constitutes part of an electrical control circuit (not shown) built into the internal circuit. In FIG. 6, 9 is a key switch for starting and stopping the engine.

Here, details of the safety switch 10 will be explained based on FIG. 1. That is, FIG. 1 is a partially cutaway side view of the safety switch 10, and in the figure,
Reference numeral 12 denotes a switch main body in the shape of a clothespin, which is composed of two divided pieces 12a and 12b that are pivotally connected to each other by a pin 13 so that they can be opened and closed. It is always biased in the closing direction by a wound spring 14.
Spherical electrode contacts 15a and 15b are respectively provided on opposing surfaces of the divided pieces 12a and 12b in the sandwiching part a at the tip of the switch body 12. A cable core 11 led out from the lead wire cable 11 and buried in the divided pieces 12a and 12b.
The ends of a and 11b are electrically connected.
In addition, each divided piece 12 of the switch body 12
Relief portions 12c and 12c are formed in a and 12b to improve the holding force of the sandwiching portion a.

In addition, the switch body 12 and the lead wire cable 11
The connecting portion with the holder is covered with an elastic boot 16 made of highly elastic resin, rubber, or the like. That is,
One end of the elastic boot 16 is fitted into a groove 12d formed on the outer periphery of the switch body 12, and the other end is crimped together with the sheath of the lead wire cable 11 by a metal fitting 17. The elastic force of the elastic boot 16 prevents the pinching force of the safety switch 10 from decreasing, and improves the appearance of the safety switch 10. Furthermore, even if the safety switch 10 or the lead wire cable 11 is subjected to a tensile force, this tensile force is borne by the elastic boot 16, and the cable core 1 of the lead wire cable 11 is borne by the elastic boot 16.
Since no tensile force is applied to the cable cores 1a and 11b, problems such as damage to the cable core wires 11a and 11b do not occur.

The safety switch 10 configured as described above is configured so that when the electrode contacts 15a and 15b are in contact, the operation of the snow blower is stopped in terms of the electrical circuit, and when the electrode contacts 15a and 15b are in the disconnected state, the snow blower can be operated. It is configured.

When working, the operator removes the safety switch 10 from the storage plate 8 and puts it on by inserting it into his/her clothes, but since the safety switch 10 has a clothespin shape, the operator can easily put it on. I can do it. Then, since the electrode contacts 15a and 15b of the safety switch 10 are in the disconnected state, the snow blower can be operated as described above, and the operator operates the key switch 9 to start the engine and proceed with the snow removal work by the snow blower. be able to. Furthermore, as the safety switch 10 is installed near the key switch 9 as shown in FIG. 6, it is visible to the operator before starting work, and
Since the snow blower cannot be started unless the operator installs the safety switch 10, the operator is required to install the safety switch 10 due to the electrical circuit, and the safety switch 10 fully performs its original safety function to ensure the operator's safety. can be ensured.

However, in an emergency, if the operator moves away from the snow blower by a predetermined distance (the length of the lead wire cable 11) or more, the safety switch 10 is removed from the operator and its electrode contacts 15a and 15b come into contact with each other. Then, as described above, the operation of the snow blower is immediately stopped electrically with good responsiveness, thereby ensuring the safety of the operator. Note that the timing at which the safety switch 10 is removed from the operator, that is, the operator's safe working area, can be arbitrarily adjusted by changing the length of the lead wire cable 11 (usually 80 to 100 cm); Since the cable 11 is led out from the center of the lower part of the operation panel 7 as shown in FIG. 6, the safe work area can be set evenly on the left and right sides. Furthermore, in the event of an emergency, the safety switch 10 can be removed from the operator as described above.
The self-cleaning effect of the electrode contacts 15a and 15b is high,
Therefore, no failure occurs in the safety switch 10. Furthermore, if the safety switch 10 has a simple, rounded shape as a whole, the operator's discomfort when wearing it is eliminated.

By the way, the shapes of the electrode contacts 15a and 15b are as shown in FIG.
5b has a concave spherical shape with a circular counterbore so that both electrode contacts 15a and 15b are in circular line contact, the holding force of the safety switch 10 is improved, and even if the operator's clothes are made of thin cloth, etc. The safety switch 10 is reliably installed, improving the operator's workability and mobility, and also provides the advantage that electrical contact failure does not occur.

Further, as shown in FIGS. 3 and 4, a wide groove 17a is formed on one opposing surface of the divided pieces 12a and 12b of the switch body 12, and a wide groove 17a is formed on the other surface to be engaged with the groove 17a. By providing the protrusion 17b, the holding force of the safety switch 10 can be further increased. Incidentally, FIG. 4 is a view in the direction of arrow B in FIG. 3.

(g) Effects of the invention As is clear from the above explanation, according to the invention, the lead wire cable 11 is connected to the end of the lead cable 11 led out from the walk-behind work machine, is pivoted around the fulcrum part so as to be openable and closable, and The safety switch 10 is constructed by providing electrode contacts 15a and 15b that come into contact with and separate from each other on opposing surfaces of the sandwiching part a of the switch body 12, which is normally biased toward the closing side. The operation of the walk-behind work machine is stopped when it is in the contact state, and the walk-behind work machine can be operated when it is in the detached state, making it easy to attach the safety switch 10 to the operator, and in case of an emergency, the walk-behind work machine can be operated easily. The safety switch 10 can be easily removed from the operator, and the operation of the working machine can be immediately stopped with good response, thereby ensuring the safety of the operator.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of the safety switch according to the present invention, Fig. 2 is a partial side view of the safety switch showing a modified embodiment of the electrode contacts, and Fig. 3 is a side view of the safety switch according to the modified embodiment. , FIG. 4 is a view in the direction of arrow B in FIG. 3, FIG. 5 is a side view of the snow remover, and FIG. 6 is a view in the direction of arrow A in FIG. 10...Safety switch, 11...Lead wire cable, 12...Switch body, 15a, 15b...
...Electrode contact, 16...Elastic boot, 17a...
Groove, 17b... protrusion, a... pinching part.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A switch that is connected to the end of the lead cable 11 leading out from the walk-behind work machine, is pivoted around a fulcrum part so as to be openable and closable, and is always biased toward the closed side. Electrode contacts 15 that come into contact with and separate from opposing surfaces of the sandwiched portion a of the main body 12
a and 15b are respectively provided, and these electrode contacts 1
5a and 15b are in a contact state, the operation of the walk-behind work machine is stopped, and when they are in a detached state, the walk-behind work machine can be operated. Safety switch. 2 The connection portion between the switch main body 12 and the lead wire cable 11 has one end fitted into the switch main body 12 and the other end connected to the lead wire cable 11.
A safety switch for a walk-behind work machine according to claim 1, characterized in that the switch is covered with an elastic boot 16 which is crimped together with a sheath of the switch. 3. The utility model according to claim 1, wherein one of the electrode contacts 15a, 15a is formed into a hemispherical shape, and the other 15b is formed into a concave spherical shape with a circular counterbore. Safety switch for walk-behind work equipment. 4. A utility model registration claim characterized in that a groove 17a is provided on one opposing surface of the sandwiching portion a of the switch body 12, and a protrusion 17b to be engaged with the groove 17a is provided on the other surface. The safety switch for a walk-behind work machine as described in item 1.