Running travel maneuvering apparatus for an engineering work vehicle

An earth handling vehicle is proposed which is capable of traveling forwardly or rearwardly to accomplish digging and loading operations, said vehicle having a chassis supported for movement on the earth by a track mechanism. The vehicle is further provided with an engine, transmission, a gearshift lever and a main clutch and further includes a maneuvering apparatus comprising front and rearwardly disposed interconnected actuators associated with steering clutches and lever mechanisms for operation of the actuators. Also, included is a supplemental clutch actuator lever which includes a portion that is operably interconnected with at least one actuator lever.

BACKGROUND OF THE INVENTION 
This invention relates in an engineering work vehicle comprising an 
operator's seat changeable to face forward and rearward for performing the 
work; an engine unit with engine, main clutch and transmission gearing; 
and a running apparatus on each lateral side of the vehicle, each with a 
steering clutch, for independently connecting and disconnecting the drive; 
to a running travel maneuvering apparatus comprising: dual actuators for 
the said main clutch, one on forward side and the other on rearward side 
of the operator's seat; a gearshift lever on forward side of the seat; and 
dual steering levers for actuation of said independent connecting and 
disconnecting of each of the steering clutches, thus for commanding 
thereby travel direction of the vehicle, with one steering lever on 
forward side and the other on rearward side of the seat with respect to 
each steering clutch, thus two steering levers for the right and left 
running apparatuses in all on each of the forward and rearward sides of 
the seat. 
In operation of the vehicle of such type, it is desirable for maintaining 
safe running travel that the operator maneuvers the vehicle with both 
hands gripping the two steering levers, in the posture proper to the 
maneuvering. However, in the case for instance of digging a frequently 
bending or meandering ditch with a backhoe apparatus provided on rearward 
side of the vehicle, the operator's seat should face rearward and when 
required to operate the gearshift lever provided only on the forward side 
of the seat then the operator must be in a posture twisted aside for 
gripping the gearshift lever with one hand and for gripping with the other 
hand the main clutch actuator on the rearward side of the seat, which 
latter is compulsorily in such lever type upstanding at a position remote 
from both of the steering levers if there is no sufficient space available 
around the seat as is actually the case in small or medium size vehicle. 
Returning to stable rearward facing posture after the gearshifting, the 
operator should change the gripping of both hands to grip the two steering 
levers from the said gearshift position, i.e. one from the gearshift lever 
and the other from the main clutch actuator lever. In such changing over 
of the gripping, the operator is apt to carelessly release for a period of 
time the clutch actuator free to connect the drive, and in view of narrow 
and poky construction around the seat, the free released time may 
considerably be long and there is thus a danger of accidentally starting 
the travel of the vehicle. In order to prevent such accidental running 
travel, it often becomes imperative that the gripping of the clutch 
actuator should intermediately be passed from one hand to the other, i.e. 
both hands should first grip the clutch actuator after releasing one hand 
from the gearshift lever and securely gripping the clutch actuator with 
the said one hand the other hand should only in that state be released to 
move near one steering lever for that hand, which is however rather a 
troublesome operation. 
SUMMARY OF THE INVENTION 
In view of the actual situation as above, this invention has as its object 
to prevent the said accidental running travel and to make the operation 
easy, only by applying simple improvement, even in the case where there is 
no ample space available around the operator's seat and so the clutch 
actuator on the rearward side of the seat is compulsorily in lever type 
upstanding at a position remote from both of the steering levers. 
To attain the object, the running travel maneuvering apparatus for an 
engineering work vehicle of the type as described hereinbefore has 
according to this invention the clutch actuator on rearward side of the 
operator's seat, which has grip or handling portion extended transversely 
to the vehicle so as to be near the handling portions of the two steering 
levers both on the same rearward side of the seat. 
Thus, by means of applying the improvement only of extending in transverse 
direction to the vehicle the handling portion of the clutch actuator so as 
to be near the handling portions of both of the steering levers, it has 
now been made possible to maintain the clutch operation during the time of 
changing from the posture for operating the gearshift lever to the posture 
proper for operation of both of the steering levers, even in the case 
where the clutch actuator is compulsorily in lever type upstanding at a 
position remote from both of the steering levers, by sliding the hand 
gripping the clutch actuator, and to make it rapid to change the gripping 
from the clutch actuator to the steering lever, so making the time very 
short when the clutch actuator is released free and preventing the 
accidental starting of the travel and at the same time making the 
operation easy. Other objects and advantages of this invention will be 
clear from the detailed description given hereunder with reference to the 
accompanying drawings.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
An embodiment of this invention is now described hereunder with reference 
to the drawings. 
An earth handling vehicle is constructed with: operator's seat 2 freely 
changeable to face forward and rearward, provided on vehicle body equipped 
with crawler running apparatus 1; and a shovel apparatus 4 and a backhoe 
apparatus 5 provided on forward and rearward sides of the vehicle body, 
respectively; thus adapted to selectively maneuver each of the two 
apparatuses 4, 5 by changing the direction of the seat 2 to face forward 
and rearward. 
The shovel apparatus indicated generally at 4 is of such construction that 
an arm 7 is pivotally connected, as shown, to the vehicle body, for free 
up-and-down movement by a lift cylinder 6. A shovel 10 is mounted on the 
extremity of the arm 7, for free up-and-down movement by a tilt cylinder 8 
and the link mechanism indicated at 9. 
The backhoe apparatus 5 is of such construction that an arm bracket 12 is 
pivotally connected to the vehicle body and arranged to oscillate, about 
an upright shaft means by a rotation mechanism indicated generally at 11. 
The backhoe comprises a mechanism for its operation and further includes 
an arm 13 comprising a boom portion 13a pivotally connected to the bracket 
12. These elements are motivated by a boom cylinder 14. The free end of 
the boom portion, i.e., 13a, is operable in a usual manner and to the free 
end is attached an arm portion 13b and a cylinder 16 for operating the 
bucket 17 through a link mechanism 17, all of which will be understood by 
those skilled in this art. 
By referring at this time, particularly to FIG. 2, it will be seen that 
there are disposed toward the front of the vehicle body, with respect to 
the operator's seat 2; a gearshift lever 19 for actuation of the 
transmission gearing 18 which is operatively connected with engine 27. In 
relative proximity thereto are provided two steering levers 21 spaced 
apart from each other and supported on the same shaft which are 
operatively connected with the respective steering clutches 20 and thereby 
are arranged to control directional travel by disengaging operation of the 
respective clutches 20. Beyond these elements and positioned toward the 
front is a pedal type actuator 23 for a clutch 22 which is associated with 
the transmission system. With further reference to FIG. 2, and to the rear 
of the vehicle there are disposed: two upstanding steering levers 24 that 
are spaced apart from each other which are operatively connected with the 
aforementioned two frontal steering levers 21. Also positioned to the rear 
is lever-type clutch actuator 25 operatively connected with the 
aforementioned pedal-type forwardly mounted clutch actuator 23. The front 
and rear steering levers 21, 24 respectively each have hand portions 21a, 
24a, respectively. The clutch actuator lever 25 is shown in FIG. 2 as 
being disposed near to and laterally outwardly of one steering lever 24 
and on the same side of the vehicle as the gearshift lever 19. This clutch 
actuator lever 25 is constructed of L-shape rod, and its lower portion is 
pivotally supported on a horizontal shaft which extends transversely 
relative to the vehicle. As shown, the rod 25 includes a horizontally 
disposed grip portion 25a which extends transversely of the vehicle and in 
close proximity to the two steering levers 24 for convenience in 
operation. 
It is believed to be apparent that with the cooperation of the elements 
discussed above, one skilled in the art can appreciate the facility and 
ease with which the operator of the vehicle which includes these controls 
can cause the vehicle to maneuver. Accordingly, when changing from a 
gearshift position with one of the operator's hands gripping the gearshift 
lever 19 and the other gripping the clutch actuator lever 25, one can 
quickly change to a steering operation with both hands gripping the 
steering levers 24. Thus, the operator may maintain the standstill state 
of the vehicle by sliding the hand which grips the clutch actuator lever 
25, along the horizontally extending bent lever portion thereof designated 
as the handling portion 25a, to a portion near one steering lever 24 on 
the remote side from the upright stem portion of the clutch actuator lever 
25, then take a posture proper to grip both of the steering levers 24. It 
is believed to be clear that one can slide one hand on the rod 25a so as 
to be able to grip said one steering lever 24, while changing at the same 
time the gripping of the other hand from the gearshift lever 19 to the 
other steering lever 24. In this manner it is thus possible to perform the 
changeover of the operator's hands instantaneously and thereby prevent 
accidental operation or movement of the vehicle through an unintended 
connection of the drive means with a freely and unintended release of the 
clutch actuator. 
The crawler of the mechanism indicated at 1 is, as usual, arranged on each 
side of the vehicle and on each is provided with brakes 26--26 in each 
line of the driving system. It will also be observed from FIG. 2 that each 
of the steering levers 21, 24 is operatively connected with the brakes 
26--26 via a pin-in-slot type link mechanism, and thus are adapted to 
actuate the brakes subsequent to a disengaging operation of the steering 
clutch 20. 
Further, FIG. 2 also illustrates a link mechanism 27 connected on the one 
hand to the clutch actuators 23, 25 and on the other hand to the brakes 
26--26, thus making it possible to have the clutch actuators 23, 25 
perform the dual function of actuating the clutch 22 and further the 
brakes 26 as well. In addition as also shown in FIG. 2, a pedal 28 
positioned toward the front of the operator's seat 2 is also operatively 
connected to the brakes 26--26 via pin-in-slot type link mechanism. Thus, 
the brakes 26--26 may be actuated either by a disengaging operation of the 
clutch actuator 23 or 25, subsequent to disconnecting the drive, or else 
by operating the pedal 28. 
The foregoing relates to a preferred exemplary embodiment of the invention, 
it being understood that other embodiments and variants thereof are 
possible within the spirit and scope of the invention, the latter being 
defined by the appended claims.