Public works machines

Abstract

A working tool of a public works machine such as an excavation bucket having a leading edge of substantially constant cross-section on which are slidably mounted a plurality of wear parts having openings complementary to the constant cross-section of the leading edge. The wear parts which may be of various configurations are positioned side by side along the leading edge to protect the leading edge from wear and to form digging teeth. The wear parts are retained on the leading edge by a removable stop member at one end of the leading edge and by a fixed or removable stop members at the other end.

Description

The present invention relates to a working tool of a public works machine, such as en excavation bucket.

In the domain of public works machines, a large variety of working tools having a leading or front edge is used. The buckets of excavators or loaders and the cutters of levelling apparatus are included in these tools whose leading edge is subjected to considerable wear and tear.

It has already been thought to protect the tool proper from this abnormally high wear by fixing interchangeable wearing blades to the corresponding leading blades. In the heretofore known tools, the changing of a complete wearing blade already means much work which can only be satisfactorily carried out in repair workshops since, it is necessary to remove the worn blades and replace them by the new blades, very often placed in position by means of rivets.

It is desirable to improve the known devices affording protection against wear, which renders the use thereof easier.

The invention has precisely for its object a working tool of public works machine, such as an excavation bucket having a penetrating or so-called "leading edge", which remedies the above-mentioned drawbacks.

In this working tool, the leading edge is constituted by:

A GUIDE COMPRISING A SECTION OF SUBSTANTIALLY CONSTANT CROSS-SECTION,

A PLURALITY OF WEARING PARTS MOUNTED ON THIS GUIDE,

AND AT LEAST TWO STOPS DISPOSED ON THE LEADING EDGE, AT LEAST ONE OF THEM BEING REMOVABLY FIXED TO SAID LEADING EDGE.

Each wearing part comprises a section which exactly complements that of the guide, whilst said wearing parts are slidingly assembled on this guide and each wearing part is made integral with the guide without interposition of complementary wedges between said guide and wearing part.

In addition, a stop member is disposed at each of the ends of the leading edge, whilst at least one of said stop members is removably fixed, in manner known per se, and that finally, said wearing parts are constituted of a material, known per se, which has a high resistance to wear and tear.

The guide is advantageously constituted by a sectioned bar of constant cross-section which is integral with the leading edge and constitutes a male bead thereof, whilst the wearing parts are shaped as rings, each provided with a slot for introduction onto this male bead and a recess, whose sections are exactly complementary of that of the guide.

Finally, wearing parts are preferably constituted, in manner known per se, by parts of a first type shaped as penetrating teeth, on the other hand by parts of a second type forming spacer parts, at least one spacer part being interposed between two penetrating teeth.

The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which:

FIG. 1 is a view in elevation of an excavation bucket in accordance with the invention;

FIG. 2 is a view in the direction of arrow F of FIG. 1;

FIG. 3 is a section along III--III of FIG. 2;

FIG. 4 is a section similar to that of FIG. 3 of a variant embodiment.

FIG. 5 is a section along V--V of FIG. 2, and

FIG. 6 is a section along VI--VI of FIG. 1

Referring now to the drawings, the working tool described is constituted by a loading bucket defined in particular by a flat base 1 and by two side sheets 2. Forks 3 known per se are intended to support the axes of articulation, on the one hand of the bucket on the dipperstick of the machine provided therewith and on the other hand of the jack manoeuvring said bucket.

The sides 2 and base 1 are themselves delimited towards the outside of the bucket, by a leading edge constituted in the present case by a section 4 of substantially circular and constant cross-section. In addition, it is noted that wearing rings, made of a material, known per se, having a high resistance to wear and tear, such as a special steel, have an internal section 5 and are provided with a slot 6. The section 5 corresponds to the outer section 4a of the section 4, whilst the distance between lips 7 of the slot 6 is slightly greater than the thickness of the sheets of the sides 2 or the base 1. Consequently, these rings are mounted to slide on the section 4.

These rings are of three distinct types 8, 9 and 10.

Ring 8 has a substantially cylindrical outer section, of circular cross-section. It constitutes a part which is particularly capable of having the function of a spacer member. One or more of these rings 8, and in the present case two rings 8, are thus interposed between two rings 9 of a second type which, in fact, each constitute a tooth of the bucket penetrating into the material to be moved.

Rings 9 constituting teeth are generally disposed only in line with the base 1. This is the case of the example shown. However, it is still possible to dispose rings 9 in line with sides 2. In the bucket described previously, only the rings of the first type, 8, are mounted on the part of the section 4 defining said sides 2.

Moreover, it is necessary to limit the slide of the rings 8 and 9 on the section 4. To this end, two rings 10 of a third type have been provided, one of which is disposed at one of the ends of the section 4 and held in this position, the other ring 10 being disposed at the other end of the section 4 and also held in this position. The members for holding the rings 10 are constituted by removable pins 11, it being understood, however, that one of the two rings 10 could be fixed definitely and not removably, according to the preferred embodiment.

It will further be specified that the thickness E of the ring 8 is substantially constant. As a variant, it is possible to adopt a ring 8a similar to ring 8, but in which the thickness is variable. In this ring 8a, the maximum thickness E.sub.2 corresponds to the intersection of said ring by the extension of the median plane 12 of the base 1. The thickness E.sub.1 at another spot is thus smaller than said thickness E.sub.2.

Finally, it will be indicated that, if the most simple embodiment has appeared to consist in making the internal femal section 5 with which rings 8, 9, 10 are provided, slide on the outer male section 4a of the section 4, a variant assembly in accordance with the invention consists in rendering a sleeve integral with each part similar to said rings 8, 8a, 9 and 10, said sleeve being provided with a lug which may slide into a groove of constant cross-section of the section 4.

Furthermore, it is obvious that the section 4 may have a cross-section other than circular, provided that the outer section 4a of said cross-section maintains a substantially invariable form along said section 4.

By adopting the arrangements which have just been described, a certain number of advantages are obtained which will now be indicated.

Firstly, it is possible to make the rings 8, 8a, 9 or 10 easily slide on section 4 and consequently to provide the leading edge, constituted by this section, with a coating which is very resistant to wear and tear. On the one hand, it is sufficient to limit the slide of introduction of said rings by a stop which may be definitively integral with the section 4 and, on the other hand, to prevent any reverse slide, this being effected by a ring 10 which is fixed removably, or more generally by any removable stop such as a simple pin. As soon as it is noticed that certain of the more worn rings are to be replaced, the ring 10 constituting one of the removable stops, at least one of which is always provided, is removed, the various rings are released and the more worn rings are thus replaced by new ones.

It will have been noted that the adoption of the arrangement which has just been described makes it very simple to fix penetrating teeth 9 onto the front edge of the bucket. It simply suffices to have provided a particular type of ring, ring 9, and to interpose it with other wearing rings 8 or 8a.

Finally, the fact of choosing rings 8a instead of rings 8 increases the periods of time between replacements or worn rings by new ones since, where the wear and tear is at a maximum, the thickness of metal E.sub.2 has also been provided to be maximum.

In addition, there are other practical advantages, particularly that of enabling wearing parts to be adopted which are made of steels which are generally difficult to weld, without it being specifically necessary to weld said parts. Similarly, the absence of welding or riveting avoids modifying the form of the corresponding working tool in the course of the successive changes of wearing parts. Finally, the spare parts may very easily be stored, these parts being of relatively small dimensions and, at the most, only of three different types: 8, 9, and 10, or 8a, 9 and 10.

Claims

What is claimed is:

1. A working tool of a public works machine, such as an excavation bucket, comprising a penetrating leading edge, with a guide having a sectioned bar of constant cross-section integral with the leading edge and constituting a male bead thereof, a plurality of wearing parts fabricated of a material having a high resistance to wear and tear and shaped as rings with a slot for introduction on said male bead and with a recess, the sections of which are exactly complementary to and slidably mountable on said guide, and at least two stop members disposed on opposite ends of the leading edge with at least one of said stop members removably fixed to said leading edge wherein each wearing part is rendered integral with the guide.

2. A working tool as defined in claim 1 wherein said wearing parts are of two types, the first type extending outwardly from the leading edge to form penetrating teeth and the second type forming spacer parts wherein at least one spacer part is interposed between two penetrating teeth.