GB2031825A - Walking-operator-accompanying type work vehicles - Google Patents

Abstract

A work vehicle accompanied by a walking operator, has an operation handle 7 attached to the vehicle free to alter the direction to extend relative thereto either rearwards or forwards and a running-direction shifter 8 provided for free selection of either forward or rearward travel of the vehicle. The vehicle also has two sensing mechanisms, one for sensing the selected extending direction of the operation handle and the selected state of the running-direction shifter and the other 21 for sensing whether or not the handle is properly gripped by the operator. The vehicle further has such a running-travel halter that is actuated responsive to sensed outputs of the two mechanisms, for stopping the vehicle travel when the handle is released from the operator's gripping, only if the vehicle is travelling to the extending- out direction of the handle, thus towards free extremity of the handle. <IMAGE>

Description

SPECIFICATION Wal ki ng-o perator-accom panying type work vehicle Background of the invention This invention relates to a walking-operatoraccompanying type work vehicle comprising: an operation handle, attached to the vehicle free to alter the direction to extend out relative thereto either rearwards of forwards, so that the operator may selectively be either on rearward or forward side of the vehicle; and a running-direction-shifter, provided for free selection of either forward or rearward travel of the vehicle.

In operating a walking-operator-accompanying type work vehicle travelling towards the operator, who is thus walking backwards, it has been a problem that the accompanying operator may stumble in such backward walking and may fall down, releasing proper gripping of the vehicle operation handle, and that the operator is injured by the vehicle and the working implement travelling onwards, since the operator has lost command of halting the vehicle travel in such dangerous instance.

Summary ofthe Invention Primary ofject of this invention is to prevent the danger as mentioned above, and to gurantee secure automatic halting of the vehicle travel when the operator loses proper gripping of the operation handle, only if the vehicle is travelling towards the operator, i.e. to the actual extending-out direction or sense of the handle, no matter in which direction it may be with respect to the vehicle body, forward or rearward, when such free selection is possible as in the type mentioned at the beginning.

To attain the object, the vehicle of the type mentioned at the beginning comprises, according to this invention: first sensing means for sensing the selected extending-out direction or sense of the operation handle and the selected state of the running-direction shifter; second sensing means for sensing whether or not the handle is properly gripped by the operator; and running-travel halting means adapted to be automatically actuated responsive to sensed outputs of said first and second sensing means for automatically stopping the vehicle travel, when the handle is released from the operator's gripping, so actuated automatically only if the vehicle is travelling to the extending-out direction of the handle, thus towards free extremity of the handle.

The vehicle is thus made to automatically halt the travel when the operator releases proper gripping of the operation handle either inadvertently (or rather forcibly under emergency contrary to the true intention) or else consciously during the travel towards the operator. The operator thus remains safe, even when the operator stumbles and falls down to lose command of the handle, prevented yet then from being run over or else injured by the vehicle and the working implement as would otherwise travel on wards.The travel-halting function is actuated only when the vehicle is travelling towards the operator, i.e. towards the handle, no matter in which direction the handle is selectively set to extend out with respect to the vehicle body, forwards or rearwards, without requiring any particular manual shifting over operation therefor, thus precluding undesirable actuation of the travel-halting function when the vehicle is travelling ahead away from the forwardly walking operator even upon releasing proper gripping of the handle during such travelling, while guranteering safety of the operator during the travel of the vehicle towards the operator as mentioned already.

Other objects of and advantages accruing from this invention may become clear from the detailed description of the preferred embodiments given hereinafter with reference to the accompanying drawings.

Brief description of the drawings The drawings show, by way of example, some embodiments of a walking-operator-accompanying type work vehicle according to this invention, wherein Figure 1 is an overall side elevation of the work vehicle, i.e., a tiller in this particular instant, Figure2 is an enlarged side elevation, partly in vertical section, of a running-direction shifter, handledirection sensor means and running-directionshifter-state sensor means, all of the vehicle, Figure 3 is a plan view of said running-direction-shifterstate sensor means, Figure 4 is a schematic wiring diagram of the circuit for actuation of running-travel halting means of the vehicle, Figure 5 is a side elevation, partly in vertical section, similar tofigure 2 but showing a modified embodiment of the running-direction shifter and said running-direction shifter-state sensor means, Figure 6 is a view taken on a plane shown at line VI-VI in Figure 5, as viewed in accordance with the arrows shown there, Figure 7 is a schematic wiring diagram similar to Figure 4, but for the modified embodiment of Figures 5 and 6, Figure 8 is a side elevation, partly in section, similar to Figures 2 and 5 but showing another modified embodiment of the running-direction shifter and said running-direction-shifter-state sensor means, and Figures 9 and 10 are a plan view partly in horizontal section and a schematic wiring diagram similar to Figures 4 and 7, respectively, of the modified embodiment shown in Figure 8.

Detailed description of the preferred embodiments Shown in Figure 1 is a walking-operator accompanying type work vehicle, i.e. a tiller in this particular instance, having an engine 1 and a transmission case 4, mounted on chassis 2 at the front end and rear end portions thereof, respectively.

A driving shaft 3 protrudes on each lateral side of the transmission case 4, for driving a rotary tiller implement 5 attached thereto. An operation handle 7 with gripping portion 6 at its tip extremity is provided to extend rearwardly of the vehicle in the state shown in solid lines. Though not illurstrated here, it is supposed that travel-resisting rod means is also attached to the vehicle for making the rotary tiller implement 5 properly till up the soil and also run the vehicle, in cooperation with said travel resisting rod means.

It is further supposed that a geared type runningdirection shifter (not illustrated) is accommodated in the transmission case 4 for shifting the driving direction of the right and left driving shafts 3 and for changing each of the forward and rearward driving speed in two steps, high and low. Maneuvering means for the running-direction shifter is designated at 9 in Figure 2, as is capable of performing both of the running-direction shifting and speed shifting by means of a single maneuvering lever 8 provided to extend rearwardly of the vehicle in the state as illustrated.

Looking further hereinto, two shafts 10,11 are provided to extend out through the wall of the transmission case 4: more particularly, a first slidable shaft 10 is provided for shifting the forward rotation of the implement 5 in high and low speeds deviating from the neutral position, and a second slidable shaft 11 is provided for shifting the rearward rotation of the implement 5 in high and low speeds deviating from the neutral position. Designated at 12 is a member pivotally supported on the transmission case 4 for free rocking movement about a transverse axis X.

Pivotally attached to this rockable member 12, for free rocking movement relative thereto about an upright axis Y, is a slidable-shaft maneuvering member 14 having an arm 13 adapted to be selectively engageable with any of mating engager members provided as securely fixed to the first and second slidable shafts 10 and 11, respectively, to extend towards this arm 13. A recess is formed in top or upper end portion of this maneuvering member 14, for receiving base or lower end portion of the operation lever 8 as fitted thereinto.Thus, when the operator maneuvers the lever 8 first in rocking movement about the transverse axis X, the arm 13 may selectively be put in operative engagement with either one of the shafts 10,11 to select the forward or rearward running travel direction and when the operator then maneuvers the leverS, in such selected engagement actuation, in rocking movement about the upright axis Y, the selected slidable shaft 10 or 11 in engagement with the arm 13 may be actuated for shifting the speed.

The handle 7 is attached, to an upper end portion of the transmission case 4, for free swinging around about an upright axis Z to extend out either rearwardly or forwardly relative to the vehicle body and for selective securing in either of the extending-out directions. The lever 8 is attached, to the maneuvering member 14, for free detachment and for free setting either to extend out rearwardly or forwardly relative to the vehicle body. Thus, when the vehicle is maneuvered by the operator standing in front of the engine 1 as installed in Figure 1, the operation handle 7 is swung to alter the extending-out direction as shown in phantom, thus forwardly of the vehicle body, and the lever 8 is detached and reattached also to alter the direction similarly as shown in phantom.The vehicle may then conveniently be run in the direction with the transmission case 4 as installed in Figure 1 facing ahead of the running travel. However, the running direction is not limited to that, but the operator may freely shift over the running direction and also shift over the speed, by means of maneuvering the lever 8.

Designated generally at 20 in Figure 2 is first sensing means and it comprises handle-direction sensor means 20a and running-direction-shifterstate sensor means 20b. Said handle-direction sensor means 20a comprises in turn: a cam plate 16 securely fixed to the transmission case 4; and a first switch 17, attached to the handle 7 to swing around integrally therewith, equipped with a cam-follower adapted to cooperate with the cam plate 16 to alter the state of being actuated and released as the handle 7 is swung around integrally herewith.

Referring also to Figure 3, said running-directionshifter-state sensor means 20b comprises in turn: a second switch 18; a first switch actuator 10a, securely attached to the first slidable shaft 10 in such a manner that when the first slidable shaft 10 is kept in the neutral position then the second switch 18 is actuated to be in open stateby abutment of this actuator 10a thereon and that when the first slidable shaft 10 is set in any active speed-changing position then the said abutment is released to thus keep the second switch 18 in closed state; a third switch 19; and a second switch actuator 1 1a, securely attached to the second slidable shaft 11 in such a manner that when the second slidable shaft 11 is kept in the neutral position then the third switch 19 is actuated to be in open state by abutment of this actuator 1 1a thereon and that when the second siidable shaft 11 is set in any active speed-changing position then the said abutment is released to thus keep the third switch 19 in closed state. In the illustrated instance, it is sensed that the handle 7 is set to extend out rearwardly of the vehicle body when the first switch 17 is actuated by abutment of the cam follower on the cam plate 16, and that the handle 7 is set to extend out forwardly of the vehicle body when the cam follower of the first switch 17 is released from the said abutment on the cam plate 16.As for the running-direction shifter state, it is sensed that the shifter is set for running the vehicle in the direction with the transmission case 4 as installed in Figure 1 facing ahead of the running travel when the second switch 18 is open and the third switch 19 is closed, and that the shifter is set for running with the engine 1 as installed in Figure 1 facing ahead of the running travel when the second switch 18 is closed and the - third switch 19 is open.

A push-button type fourth switch 21, shown in Figure 1 as a specific embodiment of second sensing means 21 for sensing whether or not the handle 7 is properly gripped by the operator, is fixed to the gripping portion 6 of the handle 7 in such a manner that when the vehicle is travelling towards the operator, who is thus walking backwards gripping the tip portion 6, then this switch 21 is actuated by the operator's gripping hand pushing same into its open position and that extraordinary non-gripping state of the handle 7 is sensed by releasing of the pushing actuation of this switch 21 back into its non actuated closed state.

As shown by way of example in the wiring diagram of Figure 4, the first, second, third and fourth switches 17,18, 19,21 are interposed, in proper interconnection therebetween, in power source line for running-travel halting means 22 illustrated as a specific embodiment thereof at a rectangular block 38 considered here to designate engine stopping means for stopping the engine 1 when the power is let through the source line. Said running-travel halting means 22 is thus adapted to be automatically actuated responsive to sensed outputs of said first and second sensing means 20 and 21, for securing the operator's safety.

Looking further thereinto, the first switch 17 is a gang type duai switch with first and second componentswitch elements 17a and 17b, respectively.

When the handle 7 is set to extend out rearwardly of the vehicle body, then the first switch element 17a is closed and the second switch element 17b is open, and vice versa when the handle 7 is set to extend out forwardly of the vehicle body, then the first switch element 1 7a is open and the second switch element 17b is ciosed. The first switch element 17a and the third switch 19 are connected in series to constitute a first circuit portion 23, and the second switch element 17b and the second switch 18 are similarly connected in series to constitute a second circuit portion 24. Thusly constituted two circuit portions 23,24 are connected in parallel to make up a circuit block which is connected in series with the fourth switch 21 and said engine stopping means 38, for ultimate connection to the power source.With such provision, it is only when the running-direction shifter is set for running the vehicle towards the extending-out direction of the handle 7 that either one of the first and second circuit portions 23,24 is closed for free passing-through of the current, and it is only under such state that the entire actuation circuit for said engine stopping means 38 is closed for introducing thereto the current from the power source upon bringing the fourth switch 21 in its closed state, thus for automatically stopping the engine 1 and as a matter of course the rotary tiller implement 5 as well. Designated at 25 is a switch which is normally kept in its open state and which is provided to be manually operated into its closed state to thus actuate said engine stopping means 38, independently of the automatic actuation circuit as mentioned above, whenever such actuation is needed.The operator is supposed to accompany the vehicle, walking backwards, always properly pressing down the fourth switch 21 when the vehicle is travelling towards the operator no matter in which direction the handle 7 is set to extend out, forwardly or rearwardly relative to the vehicle. When such backwardly walking operator stumbles and falls down, getting momentarily incapable of escaping from the travelling path of the vehicle, dangerous consequences are securely avoided by automatically halting the vehicle responsive to releasing the gripping portion 6 of the handle 7 from the operator's gripping, or more directly, to releasing the push button type fourth switch 21.

As for the fourth switch 21, it should be noted that the same may as well be substantially accommodated within the gripping portion 6 or may be replaced by any suitable means for sensing the pressure exerted on the gripping portion 6, what is essential being only that the same must be capable of sensing out the state of the operation handle 7 released of the proper gripping by the operator. In the wide scope of all of such possibilities, the same is generally referred to as second sensing means 21, for sensing whether or not the handle 7 is properly gripped by the operator, as has already been mentioned hereinbefore.

Also as already described hereinbefore, the running direction shifter was supposed in the embodiment described above to be capable also of shifting the speeds, but it may be constructed only for selectively shifting the forward and rearward running directions. Figures 5 and 6 show a maneuvering apparatus designated generally at 9 for such simple running direction shifter, and running-directionshifter-state sensor means modified accordingly and therefore designated here generally at 20b' as well as handle-direction sensor means substantially the same as before and therefore designated generally still at 20a.Figure 7 is a wiring diagram of the circuit for actuation of running-travel halting means in this case, as remains the same as before and is thus designated generally at 22 and in fact illustrated, also the same as before, as a specific embodiment thereof at a rectangular block 38 considered to designate engine stopping means.

The maneuvering apparatus 9 comprises: a slidable shifter shaft 26 provided to extend out through the wall of the transmission case 4; an engagement pin having an upright axis P2, securely fixed to tip end portion of the slidable shaft 26; a slidable-shaftmaneuvering lever 27, with one end thereof pivotally engaged with the engagement pin, the lever 27 itself being pivotally provided for free rocking movement about an upright axis P1; and a lever-maneuvering member 29 having an arm 28 engaged with the other end portion of the lever 27, pivotally provided for free rocking movement about an upright axis Y. The lever-maneuvering member 29 also has another arm 31 made to move integrally therewith, and designated generally at 30 is slidable-shaft-position setting means made to properly engage with the arm 31.Thus, when the operator maneuvers the operation lever 8 in rocking movement about the upright axis Y, the slidable-shaft-maneuvering lever 27 is moved, via the first-mentioned arm 28, in rocking movement about its pivotal support upright axis P1, and the slidable shaft 26 may be shifted between forward and rearwardly diring positions thereof for the corresponding rotation of the rotary tiller implement 5, with the neutral position interposing therebetween.

Looking in detail into said running-directionshifter-state sensor means 20b', it comprises: a switch-maneuvering arm 32 securely fixed to the slidable-shaft-maneuvering lever 27 to move integrally therewith; and a snap switch 34 with stable center neutral state, equipped with a snap lever 33 kept in operative engagement with the switchmaneuvering arm 32.The snap switch 34 has such a pair of snap-shifted contacts A,B that the contact A is closed and the contact B is open when the shifter is set for running the vehicle in the direction with the engine 1 as installed in Figure 1 facing ahead of the running travel, that the contact A is open and the contact B is closed when the shifter is set for running the vehicle in the direction with the transmission case 4 as installed in Figure 1 feeling ahead of the running travel, and that both of the contacts A,B are kept open when the shifter is in non-transmitting neutral state.As already mentioned, handledirection sensor means 20a remains same as in the former embodiment of Figures 2 - 4, and the first switch element 17a, of the first switch 17, and the contact 3, of the snap switch 34, are connected in series to constitute a modified first circuit portion 23', while the second switch element 17b of the switch 17 and the contact A of the switch 34 are connected in series to constitute a modified second circuit portion 24'. Thusly constituted two circuit portions 23',24' are connected in parallel to make up a circuit block which is connected in series with the fourth switch 21 and said engine stopping means 38.

In this embodiment of Figures 5 and 6, the operation handle 7, handle-direction sensor means 20a, lever-maneuvering member 29 and runningdirection-shifter-state sensor means 20b' are all attached to the transmission case 4 via a support member 35. The support member 35 itself is pivotal lysupported on the transmission case 4 for free rocking movement about a transverse shaft 36 but lockable by a fixing bolt 37 to hamper the rocking movement. Thus by selective setting of the bolt 37 in a proper rocking posture of the support member 35, it is possible to selectively set the tilting posture of the handle 7.

Still further modifications are possible with respecs to the running-direction shifter, and shown in Figures 8 and 9 with wiring diagram of Figure 10 therefor is an embodiment of the apparatus for maneuvering a specific example of the runningdirection shifter modification possibilities.

Designated at 107 and 108 are first and second slidable shafts in this embodiment, respectively, both extending out through the wall of the transmission case designated in this embodiment at 104. The first slidable shaft 107 may be pushed in and also pulled out from its neutral position and is supposed to have the function of setting the running-direction shifter for forward low speed running travel of the vehicle when pushed in from the neutral position and for rearward low speed when pulled out from the neutral position. The second shifter 108 may be pushed in from its neutral position and is supposed to have the function of setting the running-direction shifter for forward high speed, when pushed in from the neutral position. Designated at 113 is a member pivotally supported on the transmission case 104 for free rocking movement about a transverse axis X.

Pivotally attached to this rockable member 113, for free rocking movement relative thereto about an upright axis Y, is a slidable-shaft maneuvering member 112 having an arm 111 adapted to be selectively engageable with any of mating engager members 109 and 110 provided as securely fixed to the first and second slidable shafts 107 and 108, respectively, to extend towards this arm 111. A recess is formed in top or upper end portion of this maneuvering member 112, for receiving base or lower end portion of the operation lever designated in this embodiment at 114 as fitted thereinto.Thus, when the operator maneuvers the lever 114 first in rocking movement about the transverse axis X, the arm 111 may selectively be put in operative engagement with either one of the shafts 107, 108 and when the operator then maneuvers the lever 114, in such selected engagement actuation, in rocking movement about the upright axis Y, the selected slidable shaft 107 or 108 in engagement with the arm 111 may be actuated for shifting the speed as desired.

The operation handle, designated in this embodiment at 106, has at its lower end an attachment sleeve 115 as securely fixed thereto, and a cam plate 118 (shown in full lateral view, not in section, though the sleeve 115 is shown there in vertical section), with circumferential surface 11 8a to function as the cam surface, is again securely fixed directly under the attachment sleeve 115, so that the handle 106, the sleeve 115 and the cam plate 118 make up an integral entirety.The attachment sleeve 115 is fitted on a mating supporter sleeve 116 which is securely fixed to an upper end portion of the transmission case 104, for free swinging around about an upright axis Z common to both of these sleeves 115, 116so that the handle 106 may extend out either rearwardly or forwardly relative to the vehicle body, and for selectively securing in either of the handle extending-out directions. The lever 114 is attached, to the maneuvering member 112, for free detachment and for free setting either to extend out rearwardly or forwardly relative to the vehicle body. Thus, when the vehicle is maneuvered by the operator standing in front of the vehicle body, the operation handle 106 and the lever 114 are both set to extend forwardly of the vehicle body.In such state, the cam plate 118 is in its position rotated 180' from the state of Figure 9 which represents the rearwardly extending-out handle 106, and even if the lever 114 is then maneuvered in the direction of lowering the arm 111 of the maneuvering member 112, a blocking arm 117 securely fixed to the maneuvering member 112 is accordingly then lowered so that free tip end thereof comes close to the cam surface 118a, to almost abut thereagainstthus to block up any active actuation, i.e. pushing-in, of the second slidable shaft 108 and therefore that in such state of the handle 106 extending forwardly of the vehicle body the only maneuvering mode permitted is to actuate the first slidable shaft 107, namely to selectively set the running-direction shifter for low speed running travel of the vehicle either forwardly or rearwardly of the vehicle body, with the neutral state interposed therebetween.

Designated generally at 150 in Figure 8 is first sensing means and it comprises handle-direction sensor means 120 and running-direction-shifterstate sensor means 122. Said handle direction sensor means 120 includes a switch 119 which is a gang type dual switch, as seen in the wiring diagram of Figure 10, with parallely interconnected first and second component switch element 11 9a and 119b, respectively. When the handle 106 is set to extend out rearwardly of the vehicle body, then the first switch element 11 9a is closed and the second switch elements 1 19b is open, and vice versa when the handle 106 is set to extend out forwardly of the vehicle body, then the first switch element 119a is open and the second switch element 1 19b is closed.

Said running-direction-shifter-state sensor means 122 includes a switch 121 having a contact 121a on one hand and such a mating pair of contacts 121b,121c on the other hand that the contact 121a is connected with the contact 121 b when the shifter is set for running the vehicle rearwardly of the vehicle body (in the low speed which is the only possibility no matter in which direction the handle 106 is set to extend out, as has been mentioned herein before) and that the contact 121 a is connected with the contact 121 c when the shifter is set for running the vehicle forwardly of the vehicle body in the low speed (which is the only possibility when the handle 106 is set to extend forwardly of the vehicle body, as has been mentioned hereinbefore with respect to the function of the blocking arm 117).Designated at 123 in Figure 10 is a switch substantially the same as the fourth switch 21 of the embodiment of Figures 2 - 3, thus a specific example of said second sensing means 21 which is for sensing whether or not the handle 106 is properly gripped by the operator, just as was mentioned at the end of describing the said former embodiment. Similarly, corresponding to running-travel halting means 22 shown in Figure 4 as a specific embodiment thereof at a rectangular block 38 considered to designate engine stopping means, substantially the same running-travel halting means 126 is shown in Figure 10 as a specific embodiment thereof at a rectangular block 125 considered to designate engine stopping means. As seen in Figure 10, the three switches 119,121,123 and the engine stopping means 125 are connected in series for ultimate connection to the power source.

With such provision, it is only when the vehicle is running towards the extending-out direction of the handle 106 that the vehicle travel is automatically halted upon releasing the handle 106 from proper gripping by the operator. thus, no matter in which direction the handle 106 is set to extend out, vehicle travel is automatically halted when the operator simply releases proper gripping of the handle 106 either consciously or unintentionally, upon such emergency that the vehicle is travelling towards the backwardly walking operator and that the operator stumbles and falls down or else by some other reason wants to halt the vehicle travel but can not perform any complicated manual operation for such halting.Designated at 127 in Figure 10 is a switch substantially the same as the switch 25 in the embodiment of Figure 4, namely a switch which is normally kept in its open state and which is provided to be manually operated into its closed state to thus actuate said engine stopping means 125, independently of the automatic actuation circuit as mentioned above, whenever such actuation is needed.

Looking further into said handle-direction sensor means 120, the switch 119 has an actuator 128 resiliently urged to protrude out but retractable when pushed against the resilient urging force, and is securely attached to the attachment sleeve 115 in which a through hole is bored in axial alignment with the actuator 128. Outer peripheral surface of the supporter sleeve 116 has a cam surface 129 formed for actuating the switch 119. Within the hole of the attachment sleeve 115 there is fitted a ball 130 for free rolling rotation. The ball 130 is thus interposed between the actuator 128 and the cam surface 129, and functions as the actuation-transmitting member, namely an intermediary to transmit the camming movement to the actuator 128 for actuating same as the handle 106 is swung around, integrally with the attachment sleeve 115.With provision of this intermediary, frictional jamming force in the peripheral rotating direction as would otherwise occur during such swinging movement is quite effectively reduced to thus very smoothly actuate the actuator 128. The attachment and supportersleeves 115and 116, respectively, provided primarily for rotatably attaching the handle 106 to the vehicle body, are thus utilized dually to serve as the members for supporting the switch 119 and for actuating same, respectively.As is seen in Figure 9, the cam surface 129 consists of two portions, one for pushing the ball 130 towards the switch 119 against the resilient urging force of the actuator 128 when the handle 106 is set to extend forwardly of the vehicle body, and the other for releasing the ball 130 from such constraining pushing when the handle 106 is set to extend rearwardly of the vehicle body.

Looking now further into said running-directionshifter-state sensor means 122, the switch 121 has a rocking lever type actuator 132, and is securely attached to the transmission case 104. Provided as an integral extension of the first slidable shaft engager member 109 is a switch-maneuvering arm 131 kept in operative engagement with the actuator 132 which is thus moved in rocking as the first slidable shaft 107 is maneuvered.

Repeating the remarks, this particular embodiment of Figures 8 and 9 has thus the advantages in that simple and compact structure of the handledirection sensor means 120 is realized by the utilization of the handle attachment and supporter sleeves 115 and 116, anyhow needed and provided in the vehicle as the handle accessories, to serve as the switch supporting and actuating members, respectively, and also in that provision of the switchactuation-transmitting member 130, interposed between the switch 119 and the acutating cam surface 129, realizes quite smooth acutation of the switch 119 effectively reducing the frictional jamming as might otherwise occur and even lead to deformation of the component parts in the case of direct contact of the switch actuator with the came surface.

Claims (6)

1. A walking-operator-accompanying type work vehicle comprising: an operation handle (7,106), attached to the vehicle free to alter the direction to extend out relative thereto either rearwards or forwards, so that the operator may selectively be either on rearward on forward side of the vehicle, and a running-direction shifter, provided for free selection of either forward or rearward travel of the vehicle, Wherein THE IMPROVEMENT comprising: first sensing means (20,150) for sensing the selected extending out direction or sense of the operation handle (7,106) and the selected state of the running direction shifter, second sensing means (21,121) for sensing whether or not the handle (7,106) is properly gripped by the operator, and running-travel halting means (22,126) adapted to be automatically actuated responsive to sensed outputs of first and second means (20,150 and 21,121) for automatically stopping the vehicle travel when the handle (7,106) is released from the operator's gripping, so actuated automatically only if the vehicle is travelling to the extending-out direction of the handle (7,106), thus towards free extremity of the handle (7,106).

2. The vehicle of claim 1, wherein said first sensing means (20,150), second sensing means (21,123) and travel-halting means (22,126) comprise electrically functioning components and are electrically interconnected.

3. The vehicle of claim 1 or 2, wherein the travel-halting means (22,126) is constructed as en ginestopping means (38,125).

4. The vehicle of claim 3, wherein: the vehicle has: working implement means (5) rotatable in forward or rearward vehicle travel direction, a first slidable shaft (10) provided for shifting the forward rotation of the implement means (5) in high and low speeds deviating from the neutral position, and a second slidable shaft (11) provided for shifting the rearward rotation of the implement means (5) in high and low speeds deviating from the neutral position, and said first sensing means (20) comprises: handle-direction sensor means (20a) comprising: a cam plate (16) provided to be stationary relative to the vehicle body, and a first switch (17), attached to the handle (7) to swing around integrally therewith, equipped with a camfollower adapted to cooperate with the cam plate (16) to alter the state of being actuated and released as the handle (7) is sung around integrally herewith, and running-direction-shifter-state sensor means (20b) comprising: a second switch (18), a first switch actuator (1 0a), securely attached to the firstslidable shaft (10) in such a manner that when the first slidable shaft (10) is kept in the nertral position then the second switch (18) is actuated to be in open state by abutment of this actuator (10a) thereon and that when the first slidable shaft (10) is set in any active speed-changing position then the said abutment is released to thus keep the second switch (18) in closed state, a third switch (19), and a second switch actuator(lla), securely attached to the second slidable shaft (11) in such a manner that when the second slidable shaft (11) is kept in the neutral position then the third switch (19) is actuated to be in open state by abutment of this actuator (1 la) thereon and that when the second slidable shaft (11) is set in any active speed-changing position then the said abutment is released to thus keep the third switch (19) in closed state.

5. The vehicle of claim 4, wherein: the operation handle (7) has at its tip extremity a gripping portion (6), and said second sensing means (21) is constructed as a push-button type fourth switch (21) fixed to the gripping portion (6) of the handle (7) in such a manner that when the vehicle is travelling towards the operator, who is thus walking backwards gripping the handle tip portion (6), then this switch (21) is actuated by the operator's gripping hand pushing the same into its open position and that extraordinary non-gripping state of the handle (7) is sensed by releasing of the pushing acutation of this switch (21) back into its non-actuated closed state.

6. The vehicle of claim 3, wherein: a first sleeve (115) is fixed to the handle (106) to swing around integrally therewith, a second sleeve (116) is provided to be stationary relative to the vehicle body, for fittingly receiving the first sleeve (115) for free relative rotation therebetween, and said first sensing means (150) comprises handledirection sensor means (120) comprising in turn: a cam surface (129) provided to be operatively integral with one of the first and second sleeves (115,116), a switch (119), securely attached to the other one of the first and second sleeves (115,116), and an actuation-transmitting member (130) interposed between the cam surface (129) and the actuator (128), free to move as a cam-follower to thus actuate the switch (119) responsive to camming movement of this member (130) caused by the cam surface (129).