Mechanical Excavator Or Loader Vehicle

Abstract

In a mechanical excavator or loader vehicle having a rotary turret carrying a counterweight, jib, and scoop or bucket the invention consists in supporting said turret on the vehicle chassis by parallel linkage means whereby said turret and the parts carried thereby can be moved bodily in a direction longitudinally of the jib to vary the position of the center gravity of the vehicle.

Description

This invention relates to a mechanical earthworking machine, such as a mechanical excavator or mechanical loader, of the kind having a rotary turret provided with a jib carrying an earthworking implement, such as a scoop or bucket, and provided with a counterbalancing weight.

It is well known that with such machines it is necessary, for satisfactory operation of the machine, to provide the turret with such counterbalancing weight remote from the bucket or scoop to counterbalance the weight of the jib and the scoop or bucket when the jib is in a substantially horizontal position and the scoop or bucket is filled with earth or other material. Under other conditions, for example when the machine is being used for excavation work in which the scoop or bucket is being drawn rearwardly it is necessary that the counterweight be repositioned nearer to the jib to assist the bucket or scoop to penetrate the material to be excavated. Furthermore when the machine is not in use but being transported from one site to another it is desirable to reposition the counterweight at or nearer the center of the machine, to ensure more even balance of the jib and turret assembly between the axles of the machine.

Having regard to the circumstances above described it is desirable to provide an arrangement whereby the counterweight and turret can be used for counterbalancing loads on the jib when raising a loaded bucket or scoop, or for increasing forces on the bucket or scoop when used for excavating purposes or for balancing or trimming the machine as a whole during transportation.

The object of the invention is to provide such an arrangement and in accordance with the invention the mechanical earthworking machine comprises a chassis, a turret rotatably mounted on said chassis, a jib articulated to said turret and carrying an earthworking implement such as a bucket or scoop, and a counterweight mounted on said turret, wherein said turret is supported on said chassis by parallel linkage means whereby said turret and the parts carried thereby can be displaced bodily in a direction substantially longitudinally of the jib.

In order that the invention may be more clearly understood two particular embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic side elevation of an earthworking machine or excavator according to the invention;

FIG. 2 is a perspective view showing one form of parallel linkage for connecting the rotary turret with a platform or like member carried by or forming part of a rotary turntable (not shown) on the machine chassis;

FIG. 3 is a view similar to FIG. 1 showing the jib and bucket or scoop in different positions in full and broken lines respectively; and

FIG. 4 is a view similar to that of FIG. 2 showing a modified form of the parallel linkage mechanism.

Referring now to FIGS. 1 and 2 the machine according to the invention comprises a wheeled chassis 1, a turret support or platform 2 mounted on or forming part of a turntable 12 for rotating a turret 4 about a vertical axis x-x, and parallel linkage means 5, 6 by which the turret is supported on the turret support or platform 2. The counterweight 4 a is fixed on the turret 4.

Articulated to the turret 4 in any known manner is a jib 8 and pivotally connected to the outer free end of said jib is an arm 9 which at its free end is pivoted an earthworking implement which in the embodiment shown is a scoop or bucket 10. Pivotal movement of the jib 8, arm 9 and scoop or bucket 10 is effected in known manner by suitable rams.

The parallel linkage means comprises a pair of parallel arms 5 and 6 each of which is pivotally connected at one of its ends to the turret at 5b and 6b respectively and its other end is pivotally connected at 5a and 6a respectively to the turret support or platform 2. On the arm 5 of the parallel linkage means one end of a ram 7 is pivoted at 7a whilst the opposite end of said ram is pivotally connected to the turret 4 at 7b. The arm 5 as shown in FIG. 2, is in the form of a relatively wide platelike member to ensure correct guiding and to reduce as far as possible the effects of torsion forces. The other arm 6 is in the form of a rod.

In a modification of the invention as illustrated in FIG. 4 the operating ram 7 instead of being connected between the arm 5 of the parallel linkage means and the turret 4 (as in FIG. 3) is connected between the arm 5 and the turret support or platform 2 but in this embodiment ram 7 is pivoted to arm 5 at 7a near the upper end thereof instead of near the lower end as in the embodiment according to FIG. 3.

The parallel linkage means for effecting counterbalancing under various conditions and for various reasons operate as follows:

Assuming the machine is being used, for example, for loading work when a load is to be lifted by the scoop or bucket 10 and the jib is to be advanced as far forward as possible in a substantially horizontal position, to reach the load to be lifted, it is necessary for the center of gravity of the machine to be positioned as far back as possible, that is as far rearwardly as possible relative to the load to be lifted by the scoop or bucket 10, not only to counterbalance the load but to prevent the load causing the machine to tip forwardly when the scoop or bucket 10 is raised by the jib. In such circumstances the ram 7, preferably an hydraulic ram, is operated to cause the parallel linkage means to displace the turret 4 and the counterweight carried thereby, and consequently also the jib 8, arm 9 and scoop or bucket 10, in a direction parallel to the jib into the full line position shown at A in FIG. 3 so that the center of gravity of the machine is shifted rearwardly.

Assuming now that the machine is to be used for excavating work the ram 7 is operated to move the turret, counterweight, jib and scoop or bucket bodily into the broken line position shown at B in FIG. 3 whereby maximum weight is applied to the jib to cause suitable excavating penetration of the bucket or scoop 10 into the ground.

In circumstances in which the machine is not being used but merely transported from one site to another the ram 7 can be operated to shift the turret 4, and all the parts carried thereby, to a position intermediate positions A and B shown in FIG. 3 so as to distribute the load more evenly between the axles of the wheels of the chassis 1.

From the above description it will be understood that by virtue of the present invention the center of gravity of the machine can be shifted and the reach of the jib varied in dependence of the conditions under which the machine is used. A further advantage of the invention is that, unlike conventional machines of this type the counterbalancing of the machine is not dependent solely on the position of the counterweight itself but on the suitable positioning of the turret and all the parts carried thereby.

It will be understood that the invention is not limited to the particular embodiments herein described but various modifications can be made without departing from the scope of the invention as defined in the appended claims.

Claims

We claim:

1. A mechanical earthworking machine, such as a mechanical excavator or loader, comprising a chassis, a turret rotatably mounted on said chassis, a jib articulated to said turret and carrying an earthworking implement such as a bucket or scoop, and a counterweight mounted on said turret, wherein said turret is supported on said chassis by parallel linkage means whereby said turret and the parts carried thereby can be displaced bodily in a direction substantially longitudinally of the jib.

2. A mechanical earthworking vehicle according to claim 1, wherein said parallel linkage means comprises a pair of parallel arms each pivotally connected at one of its ends to the turret and each connected at its other end to a turret support rotatably mounted on the machine chassis, and wherein a ram is connected between one of said arms and said turret support.

3. A mechanical earthworking vehicle according to claim 2, wherein one of said arms of the parallel linkage means is in the form of a relatively wide platelike member and said ram is connected with said platelike member.