GB2224559A

GB2224559A - Drivers station of a construction machine with control lever movable to an out-of-the-way position

Info

Publication number: GB2224559A
Application number: GB8922071A
Authority: GB
Inventors: Masahiko Kobayashi
Original assignee: Kubota Corp
Current assignee: Kubota Corp
Priority date: 1988-11-08
Filing date: 1989-09-29
Publication date: 1990-05-09
Anticipated expiration: 2009-09-29
Also published as: DE3932600A1; GB8922071D0; DE3932600C2; GB2224559B; FR2638770A1; FR2638770B1; JPH0266861U

Abstract

The lever mount (11), eg for an implement control lever (9, 10), is tiltable between an approximately upright rest position and a tilted operational position which partially blocks the passage (R) provided in front of the driver's seat. The lever mount (11) is normally biased toward the rest position by a biasing element (16). Thus the upright rest position facilitates the driver's access. A bidirectionally operable locking mechanism (50) is provided for the lever mount (11) for reliably holding the lever mount (11) in position at its tilted position. The locking action of the mechanism (50) is effective not only in the rising direction of the lever mount (11) but in its tilting direction. The mechanism action in the former direction resists an over-tilting movement of the lever mount (11) beyond its permissive operation range, thereby protecting the mount (11) from damage. <IMAGE>

Description

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2ri ') /-1-4559 1 1 DRIVER'S SECTION OF A CONSTRUCTION MACHINE The present invention relates to a structure of a driver's section of a construction machine, and more particularly to a structure of a driver's section of the above type including a lever mount attached with a control lever, the mount being tiltable between an approximately upright home position and a tilted operational position inclined toward and overlapping, in a plan view, a driver's passage provided in front of a driver's seat and an urging member for urging the lever mount to the home position.

In such a driver's section of a construction machine as described above, the lever mount is tiltable because this makes it easier for a driver seated at the driver's seat to pivotably operate the control lever attached to the top portion of the mount. That is, if the mount were untiltable and remained always upright, the control lever would be located too close for the driver to operate with comfort. On the other hand, it is desirable that the lever mount be rested at the upright home position when unused so as to permit an unobstructed and easy passage of the driver who enters or exits the driver's section by way of the driver's passage. The urging member is used for facilitating a return operation of the lever mount to the upright home position.

One such construction machine is known from e.g.

a Japanese utility model laid open under No. 62-81665. In this machine, a hook type locking mechanism is provided for locking the lever mount at its tilted operational position by preventing the mount from pivoting back to the home position. This locking mechanism serves to prevent the pivot motion of the mount in only one direction, namely, its motion from the tilted position to the home position. Hence, the lever mount is maintained at the tilted operational position by the locking mechanism and the urging force of the urging member. That is, the lever mount is constantly urged by the urging member toward the upright home position and the locking mechanism cancels the urging force of this direction acting on the lever mount positioned at the tilted operational position. On the other hand, an extreme, i.e. further -3tilting movement of the lever mount beyond the operational position against the urging direction is restricted solely by the urging force of the urging member.

However, such over-tilting operation of the control lever, i.e. beyond its operational position may take place in actual construction work operations. For instance, the driver tends to apply an increasingly strong tilting force on the control lever when the earth is too hard for the bucket to dig into or when the implement receives a very strong resistance from the object and cannot move smoothly. Then, if such operation does take place, the driver's excessive force can result in damages such as undesirable looseness in all or some of the control lever, lever mount and the locking mechanism.

One conceivable method to prevent the above problem is to provide the urging member with a greater urging force strong enough to resist such excessive tilting force applied by the driver. However, this only necessitates a greater physical effort from the driver when he carries out a normal tilting operation.

In view of the above state of the art, the primary object of the present invention is to provide an improved structure which can reliably and firmly maintain the lever mount at its tilted operational position even if an excessive tilting force is applied to the mount and yet which permits the driver to carry out a normal tilting operation easily and effortlessly.

For accomplishing the above-described object, a structureof ilriver's sectinn cf a coils truct.; on inachine is Drovided,, .a--core.ing to the present invent-inn, the structure having a lever mount attached 4---oa control lever, the lever mount being pivotable between an approximately upright home position and a tilted op erational position inclined toward and overlapping, in a plane view, a driver's passage provided in front of a driver's seat and an urgingor biasing member for urging the lever mount to the home or rest position, wherein a locking mechanism for locking the lever mount by bidirectionally restricting pivotal movements thereof in both rising direction toward the home position and tilting direction opposite to the home position, the locking mechanism being releasable by releasing means.

According to the above feature of the invention, a return operation of the lever mount can be effortlessly carried out with the aid of the urging force of the urging member, as is the case with the aforementioned conventional structure. Further, even if the lever mount locked at the tilted operational position by the locking mechanism receives an excessive force for further tilting the mount from this position, the locking mechanism effectively prevents the lever mount from being tilted any further. As a result, the locking mechanism can effectively protect the lever mount from such excessive operational force, thereby to prevent damage or undesirable looseness of the lever mount. Moreover, unlike the aforementioned convention where the urging member needs to have a significantly strong urging force to prevent such excessive tilting movement of the lever amount, the structure of the invention permits use of an urging member having a moderate urging force and thus easier to operate for a normal tilting operation.

Further and other objects, features and effects of the invention will become apparent from the following more detailed description of the embodiments of the invention with reference to the accompanying drawings.

1 Accompanying drawings illustrate one preferred embodiment of the invention; in which, Fig. 1 is a side view showing an entire backhoe vehicle equipped with a dozer implement, the vehicle being one example of a construction machine in which a structure of the invention is utilized, Fig. 2 is a plan view showing the.

driver's section of the vehicle of Fig. 1.

Fig. 3 is a partially cutaway side view of the driver's section of Fig. 2, Fig. 4 is a partially cutaway side view showing a vicinity of a control lever mount included in the driver's section, and Fig. 5 is a perspective view showing a structure for operating steering control valves.

In Fig. 1, there is shown a backhoe vehicle equipped with a dozer implement. The vehicle includes a crawler-propelled vehicle body mounting a dozer implement 1, a swivel deck 4 pivotably mounted on the vehicle body and having a driver's section 2 and an engine housing 3 and a backhoe implement 6 connected 2.5 to the swivel deck 4 via a swing bracket 5. This backhoe implement 6 includes a boom 6b, an arm 6a and 1 1 -7a bucket 6c and is freely pivotable about the bracket 5 relative to the swivel deck 4.

Fig. 2 is a plan view showing the driver's section 2 in detail. As shown, this driver's section 2 includes a driver's seat 8, a right and left pair of control levers 7a and 7b disposed in front of the driver's seat 8 across a driver's passage R and used for independently controlling a right and left pair of crawler propelling units, a cross-pivotable lever 9 disposed at a left side of the seat 8 vehicle travelling direction, the lever 9 constantly connected with an unillustrated arm control in the being control valve and being selectively connectable with an unillustrated turn control valve and an unillustrated swing control valve thereby moving the arm 6a together with the swivel deck 4 or the arm 6a together with the swing bracket 5, and a further cross-pivotable control lever 10 disposed at a right side of the driver's seat 8 and used for operating the boom 6b and the bucket 6c.

The pair of control levers 9 and 10 are substantially identical to each other in their mounting construction and are mounted respectively on a right and left pair of box-shaped lever mounts 11 and 11 attached on portions 4a of the swivel deck 4, as shown in Fig. 3. Then, the mounting construction c X -8of these levers 9 and 10 will be described by taking the one lever 9 for example. Fig. 3 particularly shows the mounting construction of the control lever 9. As shown, the lever mount 11 is pivotable on a pivot shaft 12 in the fore and aft direction of the krehilcle by means of a control handle 13 provided at a rear side of the lever mount 11. More particularly, referring now to Fig. 4, with a forward manual operation of the control handle 13, the lever mount 11 is pivoted counterclockwise from an approximately upright home position thereof drawn with solid lines in Fig. 4,,into a tilted operational position drawn with dashed lines in Fig. 4 in which latter position the lever mount 11 comes to overlap the driver's passage R as viewed from above.

Next, a stopper-locking mechanism 23 will be described with reference to Figs. 3 and 4.

This stopper-locking mechanism 23 essentially includes a fan-shaped engaging member 14 as a first engaging member fixedly attached to a lower portion of the lever mount 11 and defining a plurality of engaging cutouts 20a, 20b in one peripheral edge of the member 14, and a wedge-shaped stopper 19 as a second engaging member selectively.engageable with one of the engaging cutouts 20a, 20b of the engaging member 14. The stopper 19 is slidably received in a stopper support 18 via an urging spring 24 interposed between a bottom face of the stopper 19 and an opposing bottom face of the stopper receiver 16, with the spring 24 urging the stopper 19 to project out of the receiver 18. Then, the selective engagement between the wedgeshaped stopper 19 and one engaging cutout 20a or 20b of the engaging member 14 is realized and maintained by a projecting motion of the stopper into the cutout 20a, (20b) urged by the spring 24. That is, an engagement between the stopper 19 and the uppermost cutout 20a provides the above-described upright home position; whereas, an engagement between the stopper 19 and one of the lower cutouts 20b provides the tilted operational postion. These lower cutouts 20b provide a plurality of tilted operational positions of the lever mount 11 each selectable by the driver for his maximum convenience.

For releasing the stopper-locking mechanism 23 having the above-described construction, there is provided a lock-releasing mechanism 50 which essentially includes a manually operable release control lever 21 and an arcuate-shaped lock release element 22 operatively connected via a pivot shaft 25 to one end of the release control lever 21. The 2.5 arcuate release element 22 has a peripheral working edge substantially extending along the peripheral edge 1 1 2.5 -10of the fan-shaped engaging member 14. The release control lever 21 is attached to a rear face of the lever mount 11 at a position which permits an easy operation by the driver seated at the driver's seat 8. Also, the release control leviepr 21 is pivotable between a lock releasing position OFF and a locking position ON and normally urged toward the locking position ON by an urging fr..r--e of a return spring 26 attached to the distant end of the release element 22.

Then, referring to Fig. 4, if this release control lever 21 is manually pivoted about the support shaft 25 from the locking position ON toward the control handle 13 and brought into the lock release position OFF, the lock release element 22 is moved from an inoperative position B located inwardly in the peripheral direction of the fan-shaped engaging member 14 into an operative position A located outwardly in- the peripheral direction, whereby the lock release element 22 comes into contact with and pushes, with its peripheral working edge, a leading end of the stopper 19 presently engaged deeply into the cutout 20a or 20b out to a shallow engaging position. At this shallow engaging condition, a complete disengagement between the stopper 19 and the cutout 20a ^(20b) has not yet taken place since the lock release element 22 at its operative position A acts to loosely receive the k -11stopper 19 in such a manner as to prevent a new engagement between the stopper 19 and the adjacent cutout 20b (20a). On the other hand, at the above lock release position OFF, the release control lever 21 is operable together with th'p control handle 13 with one hand of the driver's. Then, as the driver operates these lever 21 and the control handle 13 by gripping these together with his hand with an operating force exceeding a predetermined value, by a cam effect of a curved edge portion 14a of the engaging member 14, the stopper 19 exits completely from the cutout 20a (20b). In this condition, the locked condition of the lever mount 11 is completely released and the lever mount 11 becomes freely pivotable into a new position, i.e. the home position or one of the tilted operational positions.

After tilting the lever mount 11 to a desired position, if the driver releases his hand from the control lever 21 thereby to allow the latter to return to the locking position ON by the urging force of the return spring 26, the release element 22 moves back to the inoperative position B to allow a deep engagement of the stopper 19 into the new cutout 20a (20b), whereby the lever mount 11 is locked at this new position.

Summarizing the above operation procedure, first, 1 1 -12the release control lever 21 is operated into the lock releasing position OFF. Then, the control lever 21 at this position is operated together with the control handle 13 by one hand operation, thereby to move the lock release element 22 into the perative position A.

At this operative postion A, while the stopper 19 acts as a detent for preventing a return motion of the lever mount 11 in the manner desrcribed before, the lever mount 11 can be moved into a desired tilted operational position which is conveniently distant from the driver seated at the driver's seat 8 who is to operate the control lever 9 or 10 attached on the lever'mount 11.

After the lever mount 11 has been set at the desired position, the lock releasing lever 21 is released thereby to return the lock release element 22 to its inoperative position B by the urging force of the return spring 26, and the stopper 19 comes into complete and firm engagement with the new cutout 20b.

With this, the lever mount 11 is firmly locked at this new position and cannot move in either of the rising and tilting direction regardless of the magnitude of an operational force applied by the driver on the lever mount 11.

When the driver mounts or dismounts from the driver's section via the driver's passage R, the x; W ( 1 stopper-locking mechanism 23 is released to allow the lever mount 11 to return to its upright home position by the urging force of the spring 16. Thus, the lever mount 11 is completely cleared from the space above the driver's passage, thereby' facilitating the driver's mounting or dismounting action. This upright home position is determined by the cutout 20a, whereas the fan-shaped engaging member 14 is held in position by the stopper 15 also. Further, the spring 16 has one end thereof secured to a spring retainer 17 disposed below the pivotal center, i.e. pivot shaft 12 of the lever mount 11.

The vehicle-propelling control levers 7a and 7b are identical to each other in construction and only one lever 7a is shown in Fig. 5. As shown, the control lever 7a is detachably and pivotably connected with a pivot element 27 operatively connected via attaching bolts 28, 28 with a vehicle-propelling control valve V. As shown in Figs. 3 and 5, the operational end of the control lever 7a (7b) is bent towards the driver's seat so as to be positioned close to the operational end of the control lever 9 mounted on the lever mount 11 at its tilted operational position. This bending lever arrangement further improves the operation efficiency of the structure of the invention. Further, the pivot element 27 and the A control lever 7a or 7b are exchangeable with a detachable pedal 29, such that the propelling operation of the vehicle can be effected by either a hand operation of the lever 7a or 7b or a foot operation of the pedal 29.

In place of the spring 16, other various types of urging means such as a gas spring can be used. That is, the urging member 16 is to be understood as generically including all such urging means.

The invention may be embodied in various other types of construction machines such as a shovel loader.

In the foregoing embodiment, the tilting motion of the lever mount 11 takes place in parallel with the driver's seat 8. Instead, it is conceivable to adapt the lever mount 11 to tilt forwardly with a slight lateral displacement relative to the driver's seat 8 if such tilted position is more convenient for the driver's lever operation.

The invention may be embodied in other specific forms without departing from the sprit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all h ( 1 1 2.5 changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

1

Claims

CLAIMS lever approximately operational A driver's section of a

construction machine, wherein a lever mount is attached to a control lever, the mount being pivotable between an upright rest position and a tilted position inclined towards a driver's passage provided in front of a driver's seat.and a biasing member for urging the lever mount to the rest position, and wherein a locking mechanism is provided for locking said lever mount by restricting pivotal movement thereof, said locking mechanism being releasable by releasing means.
2. A driver's section as claimed in claim 1, wherein the locking mechanism restricts pivotal movement bidirectionally, in both a rising direction toward the rest position and a tilting direction opposite to the rest position.
3. A driver's section of Claim 1, wherein said locking mechanism includes a first engaging member fixedly attached to a lower portion of said lever mount and defining a plurality of engaging portions and a second engaging member attached to a swivel deck via a support and normally urged toward an engaging direction thereof.

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4 4. A driveris sec.,tion Of Claim 3, wherein said first engaging member has a fan-like configuration, said engaging portions of the first engaging member being a plurality of cutouts defined in one peripheral edge of said first engaging member while 4a ' id second engaging member comprises a wedge-shaped stopper selectively engageable with one of said cutouts.
- A driver's section of Claim 4, wherein said cutouts include a first cutout corresponding to said upright rest position and a second cutout corresponding to said tilted operational position.
6. A driver's section ef Claim 5, wherein said cutouts include at least one further cutout corresponding to at least one another tilted operational position.
7. A driver's section of Claim 4, 5 or 6 including a lock rel".se mechanism associated with the second engaging member and. having an arcuate-shaped lock release element with a peripheral working edge corresponding toa peripheral edge of'said fan-shaped first engaging member, whereby a lock release action is affected bya movement of said lock release element in the radial direct.ion of said fan-shaped first engaging member.

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8. A driver's section of Claim 7, wherein each of said cutouts has a curved edge portion for permitting a partial disengagement of said first engaging member from said cutout thereby enabling a pivotal movement of said lever mount with a release operation of said lock releasing mechanism.
9. A driver's section of Claim 7 or 8, wherein a control handle is provided adjacent an upper end of said lever mount, said control handle being operable with a single hand-gripping operation together with said release control lever after a lock releasing operation.
10. A driver's section substantiallv as hereinbefore described with reference to the accompanying drawings.

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