CA1258827A

CA1258827A - Excavator/loader

Info

Publication number: CA1258827A
Application number: CA000483712A
Authority: CA
Inventors: Ridley Stokoe
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-06-12
Filing date: 1985-06-12
Publication date: 1989-08-29
Also published as: DE3563229D1; EP0168946A1; AU4345485A; AU583513B2; EP0168946B1; ATE35007T1; GB8414960D0

Abstract

ABSTRACT

The invention is an earth-moving vehicle which performs the functions of excavator and loader.
Conventional such means are an excavator at one end and a loader at the other. The invention is a vehicle in which the alternative functions are both carried out at the same end, thereby avoiding duplication of operator seating and controls. The excavator/loader has an operating arm in two sections, the first of which may be pivoted into a position which is roughly vertical or inclined rearwardly, for the loading function. The first arm section can be pivoted forwards for the excavating function.

Description

~X5~7 ~XCAVA ~ LOAD~R
___ ~__ ~he present inven-tion is a novel vehicle which combines the functions of excavator and loader and displays important ad~antages over prior vehicles of this general t~pe A mlmber of vehicles areavailab].e which are described ~ariously as excavator/loaders, digger/loaders or bacl~oe/
loaders and which are designed to perform two main functions. First].y, an articulated arm at one end of the vehicle, usually the rear, carries a bucket designed to lo dig below ground level and -thereby excavate a trench or hole. ~his excavator.bucket is normally narrower -than the overall width of the vehicle and digs back towards the vehicle. Secondly, the vehicle carries, usually at its front end, a loading bucket for lifting excavated material from ground level upwards in-to lorries for transport awa~ from the excavation site. ~he loader bucket is usually at least as wide as the vehicleO Vehicles are also available which perform onl~ one of these func-tions, or which perform a second function b~ the provision of special secondary attachments.
A major di~iculty in designing vehicles of this general t~pe is that of providi-ng ade~uate counter-balancing to balance -the effect of the respective operating bucket under load. ~hus the unbalancin~ moment of a full loader bucket at the end of the loader arm has to be off-set by a consider-able weight rearward of the adjacent vehicle wheels, especially when the loader is operating on a sloping site and/or at the /~

;3827 limits of its reach. This weight must either take the ~orm o~ heavy b~last built into the vehicle or be provided by the weight of a di~ger arm and bucket fitted to the other end of the vehicle~ This normally means that eithe~ the vehicle carries undesirable excess weight in its design or the two functions must be performed at opposite ends of the vehicle.
A significant disadvantage of such prior excavator/
loaders is that, since the two functions are per~ormed separately at opposite ends of the vehicle, seating and controls have to be provided for the operator facing each end of the vehicle as desired. Such duplication adds to both the cost and dimensions of the vehicle, In German Published Patent ~pplication (D0~) No.
3331516, an excavator/loader is illustrated in which both functions are carried out at the same end of the machine.
In order to achieve this result, the operating ~ib is ~ormed in three sections, described respectively as a pre-jib,a main jib and an arm. When the machine is to function as a loader~thelmain jib and the arm are set essentially at right angles to each other and remain in that position throughout the loading operation. When the machine is to function as an e~cavator, the pre-jib and the main jib are set in approx-imate relative alignment and remain in that position through-out -the excavating operation. Controls are provided to achieve the relative movements o~ the three jib sections, as well as the movement o~ the aib overall relative to the 3~ 27 turntable upon which it is mounted and the movement of -the operating bucket relative to the jib.
It is an object of the present invention to provide an improved excavator/loader in which both f11nctions are performed at the same end of the vehicle, which none-theless is stable in both modes of operation and which is of a more simple design, and is therefore easier to operate and maintain, than p~or forms of excavator/loader.
The excavator/loader according to the present invention comprises a chassis carrying an articulated operating arm having only two sections, a first arm section supported at one end thereof upon said chassis for pivotal movement relative thereto about a horizontal axis, and a second arm section pivoted to the other end of said first arm section for pivotal movement relative to said first arm section about a horizontal axis, said first arm section being pivotable into a position (the "stowed"posi~on) in which the point of pivoting ~gether of the two arm sections lies above or rearwa~d of the point of pivoting of the first arm section upon the chassis.
~ virtue of the above-defined features, the excavator/loader of the present invention is ableto function, in a stable manner, both as an excavator when the first arm section is in use and also as a loader when said first arm sectDn is in its stowed position~ No third arm section is necessar~. ~he duplication of controls associated with a vehicle having the two functions at opposite ends is rendered unnecessary. Thelocating of L ~2S~8~

the fi.rst arm section as speci.fied during theloading operation reduces or removes the need for counter-balance weighting in the vehicle~ In spite of its diversity, the excavator/loader is a relatively simple vehiclé~
~he point at which the first axm section is pivoted to the vehicle (hereinafter referred to as the first pivot point) depends upon other features of -the overall design o~ the vehicle but in general it will normally lie towards the forward end of the vehicle. It is about this pivot point that the arm operates when in its excavating mode~
Preferably it is located in the general region of the front end of the wheel-base or other ground-contacting area (as for example when the vehi.cle is mounted on tracks)~
~hus~ for example, when -the vehicle is wheel-mounted, the first pivot point preferably lies in the region of the axis of the front wheels or slightly forward or rearward thereof.
The first pivot point i.s preferably set low on the v~hicle. ~hus, for example, in the case of a wheel~mounted vehicle, the first pivot point preferably lies below the

2 height of the upper circumference of the front wheels of the vehicle~ When the overall vehicle geometry does not allow the pivot point to be set between the front wheels or in the corresponding position in the case of a track-la~ing vehicle, as for example when the operating ar~ is 2~ ~ounted upon a turn-table, then the pi.vot point may be set forward of that position, for example low on an overhanging forward extension of the chassis.

` ~L2~827 ~ he rnountin~ of the first pivot point i9 such as -to allow pivoting about a hori~ontal axis, to permit the excavating function to be carried out and also to enable the first arm section to be stowed. In addition, it is advantageous to provide for pivoting of the arm about a vertical axis 7 to allow -the vehicle to excavate to at least a limited extent generally sideways of the vehicle~ ~he mounting at -the first pivot point may therefore comprise two separate pivots, of which it is preferred that the vertical-axis pivot is towards the rear.
If desired, the first pivot point may be so mounted as to be displaceable laterall~ relative to the length of the vehicle so that the latter may more effectively operate close to an obstruction when in it~ excavating mode.
~his may be achieved by mounting the pivot point upon a laterally displaceable carriage or bracket or, less conveniently, upon a turntable~
In the stowed position of the first arm section, the point at which the latter is pivoted to the second arm section (hereinafter referred to as the second pivot point) lies above or rearward of the first pivot point. In order not undul~ to limit the outreach of the arm in its loading function, the second pivot point preferably lies at most onl~ a short distance, measured ina horizontal direction, behind the first pivot point. ~or example, the horizontal distance may be of the general order of about 25 per cent o~ the len~th of the wheelbase or other ground-contacting area of the vehicle, ~hus, in its stowed position, the fir3t arm section may be vertical or more pre~erably may - 6- 3L25~3~3~7 have a rearward orientation, inclined -to the vertical by an angle of the order of 5 to 45 degrees, e.g. 20 to 40 de~rees, although the angle may be greater i~
desired.
~he first arm section may be lockable in its stowed position, but need no-t be so. For example, an electrical, hydraulic or mechanical locking device may be provided so that, when the vehicle is being used in its loading mode, the operating lever which controls the pivo-ting of the first arm section, or a ram which brings about that pivoting, is rendered inoperative.
To gain the maximum benefit of the vehicle of the present invention, it is desirable that the bucket be of a quick-release variety in order that, when the operator changes from a~ excavating to a digging operatlon or vice versa, a bucket appropriate to the relevant operation can rapidly be fitted. Thus the attachment fitting may be of a type which permits a quick interchange by conventional manual methods, for example of the nut-and~bolt type.
Alternatively, an attachment mechanism of the claw type, optionally operable by the operator without descending from the vehicle, may be pre~erred.
~ he stability of the vehicle, especially in the excavating mode, may be enhanced by the provision of out-riggers or other ground-contacting stabilisers, which may be used merely to brace the vehicle against the ground or may, by jac~ing, lift two or all of the wheels clear of the ground. Manoeuvrability of the vehicle may be enhanced b~ providing a skid-steer drive arrangemen-t.
~he inventian will now be further described with re~erence -to the accompan~ing drawings, in which:-~ ~ig. 1 is an elevation ~rom the side of one form of excavator/loader according to the present invention; and ~ig~ 2 is a plan view of the excavator/
loPder of ~ig. 1.
More specifically, in ~ig. 1 the excavator/loader is illustrated with the vehicle in loading mode shown in full line and with the excavating mode operation shown in chain-dotted`line. In ~ig. 2, the excavator~
loader is shown in excavator mode and with outriggers and stabiliser extended.
~he illustrated embodiment is a particularl~ compact form of the invention. ~he vehicle has a wheelbase (that is, the horizontal distance between ~ront and rear axles) of about 1.3 metres and an overall maximum dimansion, with the operating arm and bucket retracted, of less than 3 metres~
The illustrated vehicle has front wheels 3, 3 and rear wheels 4, 4 and carries a single, forward-~acing seat 5 fo~ the operator.
The operating arm consists of a first arm SeCtiQn ~5 6, pivoted about a horizontal pivot 7 which in turn is linked to the vehicle body about a vertical pivot 8~ and a second arm section 9, pivo-~ed at 10 to the outer end ~5~38 -- 8 ~
of -the ~irst arm section 6. The ve~-tical pivot 8 lies about 0.2 metres -to the rear of the axis o~ rotation of the ~ront wheels 3, 3 and the horizontal pivot 7 lies approximate]~ in line with that axis.
At the outer end of second arm section 9, a bucket (11 or 12) appropriate to the operating mode is carried.
The bucket 11 is the loading bucke-t and the bucket 12, mounted the opposite wa~ round from bucke-t 11, is the excavating bucket. Each bucket is secured to the arm at just two moun-ting points (as ~iewed from the side), namely a pivot mounting 13 and a con-trol link mounting 14, by means of which latter the tipping action is transmitted to each bucket. Alternatively, the mounting points 13 and 14 may support an intermediate carrier plate on the end of the operating arm, the alternative buckets then being detachably secured on the carrier plate by a quick-release mounting.
Operation o~ the arm and bucket is effected by means of four double-acting hydraulic ram5, A first ram 15 controls the pi~oting of the ~irst arm sec~on 6 about the firs-t pivot point 7; a pair of rams 16, 16 effect relative pivoting of the arm sections about the second pivot pOilit 10; a fourth ram 17 controls the bucket tipping.
The excavator/loader is also provided with out-riggers 18, 18 and a rear stabiliser 19, which may be lowered into contact with the ground to give increased stabilit~ o~ operation of the vehicle in the excavating mode.

9 ~ ~5~32~
As i.s most clearly shown in Fig~ 1, the vehicle may function as a convention.al excavator (the chain-dotted feature) by operation of the four rams as desired.
However, the design is such that, by operatio~ of the ram 1~, the first arm section 6 may be swung upwards and backwards until the pivot point 10 is in the position illustrated in full line, in which position the pivot point 10 lies about 0.3 metres to the rear of pivot point ~ With the first arm section 6 in this position, where it is incli.ned backwards at an angle of the ord.er of 30 degrees to 40 degrees to the vertical, the vehicle ma~ be used as a conventional . loader, by operation of -the rams 16 and 17 only.
~hus the vehicle of the present invention is a true excavatorJloader, in which the two primary functions may be carried out using a single set of controls b~ an operator i.n a single forward-facing seat.

Claims

1. A vehicle which can function alternatively as a loader and as an excavator and which comprises a mobile chassis having a ground-contacting area defined by wheels or tracks, a first generally horizontal pivot upon said chassis in the region of one end of said ground-contacting area, an articulated operating arm having only two sections, a first said arm section being pivoted at a first end thereof about said first pivot whereby said first arm section may pivot between an outer position wherein said arm section extends away from said ground-contacting area and an inner position wherein said first arm section is inclined generally inwardly with respect to said ground-contacting area with the second end of said arm section disposed above said area, a second generally horizontal pivot at the second end of said first arm section, a second section of said operating arm being pivoted about said second pivot at a first end of said second arm section, and bucket attachment means at the second end of said second arm section, whereby the vehicle is able to function as a loader when said first arm section is in said inner position thereof and the vehicle is able to function as an excavator when said first arm section is in said outer position thereof.

2. A vehicle according to claim 1, wherein said inner position of said first arm section is inclined at an angle of from 5 to 45 degrees to the vertical.

3. A vehicle according to claim 2, having locking means selected from the group comprising electrical, hydraulic and mechanical locking devices, to retain said first arm section in said inner position thereof.

4. A vehicle according to any of claims 1 to 3, wherein the distance between said first pivot and said second pivot, measured in a horizontal direction, is of the order of 25 per cent of the length of said ground-contacting area when the first arm section is in its inner position.

5. An excavator/loader comprising a chassis mounted upon respective forward and rearward wheel axles, a first generally horizontal pivot located upon said chassis in the region of said forward wheel axle, a first operating arm section pivoted upon said first pivot at one end of said first arm section, a second generally horizontal pivot located upon the other end of said first arm section, a second operating arm section pivoted at one end of said second section upon said second pivot, first hydraulic ram means for moving said first operating arm section between an outboard position wherein said section extends from the area defined between said two axles in a direction beyond said forward axle and an inboard positon wherein said section lies above said area in a direction rearwardly inclined at an angle between 5 and 45 degrees to the vertical, second hydraulic ram means for swinging said second operating arm section about said second pivot relative to said first arm section, and bucket attachment means at the other end of said second operating arm section.

6. An excavator/loader according to claim 5, having a loader bucket and an excavator bucket, said buckets having means for interchangeable engagement with said bucket attachment means.

7. An excavator/loader according to claim 5 or claim 6, wherein said first arm section is mounted upon both said first generally horizontal pivot and also a generally vertical pivot.