BACKGROUND OF THE INVENTION

The invention relates to apparatus for crushing or cracking tough materials, such as all types of rock, concrete, slag and cast iron, the apparatus being mounted in use on an hydraulically-powered arm of a excavating vehicle. the term "excavating vehicle" as used herein means a vehicle having wheels or which is track-laying having an arm of one or more articulated portions, said arm being powered wholly or partially by hydraulic power and usually having mounted at an extremity of the arm a bucket for earth excavation or some other tool, for example a pneumatic or hydraulic percussion device, or means for manipulating objects such as telegraph poles, posts and the like.

Apparatus of the present invention is particularly suited for secondary breaking in a quarry i.e. after blasting but before static crushing. This is often required, or at least preferable, to permit transportation of the material. Conventionally such breaking has been accomplished using a drop ball or hydraulic hammer which presents various disadvantages and does not provide for uniform crushing of material.

The present invention seeds to provide crushing apparatus for attachment to existing vehicles, which apparatus is powerful enough to crush substantial volumes of tough material. The invention also seeks to provide a vehicle having such apparatus fitted thereto.

SUMMARY OF THE INVENTION

The invention provides therefore crushing apparatus adapted for attachment to an arm of an excavating vehicle, the apparatus comprising a first member having a jaw on an end thereof and, remote from said jaw, fixing means by which the first member may be mounted on the vehicle arm, a second member movably mounted on said first member and having a jaw co-operable with the jaw of said first member to crush material located therebetween, and a piston and cylinder assembly mounted on one of said first and second members and connected to the other of said first and second members and operable to cause relative movement between said jaws.

The piston and cylinder assembly provided on the apparatus is preferably hydraulically driven and may be driven by the hydraulic compressor of the vehicle to which it is, in use, attached.

Preferably the second member is pivotally mounted on the first member.

Desirably the first member comprises a pair of spaced apart limbs between which the second member is mounted. Corresponding bearing surfaces are preferably provided on the inner faces of said limbs and on the second member to prevent relative sideways or twisting movement between the first and second members

Preferabaly at least one of the jaws is provided with means for engaging with material to be crushed. The engaging means may comprise a plurality of projections which are desirably spikes.

Preferabaly the cylinder of the piston and cylinder assembly is mounted for limited pivotal movement on the first member at a point between the ends of said first member and the piston is pivotally connected at its end to the second member.

The fixing means desirably comprises a pair of pivotal mountings, one of said mountings being co-operable with the mounting provided on the vehicle arm for use normally with an excavating bucket, the second of said mountings being co-operable with the mounting provided on the piston or cylinder of an excavating-bucket-tilting ram provided on said vehicle arm. A plurality of fixing means may be provided to allow the apparatus to be transferred from one vehicle to another different vehicle having different fixings.

The present invention also provides an excavating vehicle, as hereinbefore defined, fitted with apparatus according to any of the preceding seven paragraphs.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a crushing apparatus attachment;

FIG. 2 is a perspective view of the attachment of FIG. 1; and

FIG. 3 is a diagrammatic side view on a reduced scale of an excavating vehicle fitted with a further crushing apparatus attachment.

FIG. 4 is a side view of the crushing attachment with the jaws in their closed position showing the relatively large material holding space between the first and second jaws.

DETAILED DESCRIPTION

The attachment shown in the drawings comprises a first member 10 comprising a jaw portion 12 at one end from which extends two spaced parallel mounting members 14. A pivot 16 is provided between the members 14 and on this pivot is mounted a second member 18. The member 18 has a jaw portion 20 at one end which connects with a mounting portion 22 rotatable about the pivot 16. Both of the jaw portions 12, 20 are provided with a plurality of spikes 24 on their inner edges. A kidney shaped projection 26 extends from each side of the mounting portion 22 and contactingly engages with a projection 28 on the inside of each of the mounting limbs 14. The engagement of the projections 26, 28 for all relative positions of the members 10, 18 restricts relative sideways or twisting movement therebetween.

A cylinder 30 of a relatively short stroke hydraulic ram 32 is mounted, by means of a beam (not shown) fixed to the cylinder between its ends, for limited pivotal movement about an axis 38 on trunnions provided on a cradle 36 welded on either side of the mounting members 14. An end region of a piston 40 of the ram 32 is pivotally connected to a yoke 42 fixed to the mounting portion 22 of the second member 18. By adopting a short stroke cylinder mounted on the first member 12 at a point between the ends thereof the overall length of the apparatus is kept to a minimum and a fast operating cycle is achieved. The length of the piston 40 and the distance between the yoke 42 and the pivot 16 are carefully selected so that as the jaws arrive at a normal crushing position the piston is substantially tangential to the arc defined by the yoke 42 as the member 18 pivots about the axis 16. This means that the maximum force is transmitted to the jaws at the time of crushing.

As is shown in FIG. 4, when the jaws 12 and 20 are in the closed position, they abut at the free ends and define a relatively large material holding space. This permits the rock to be broken and to fall out of the jaws without being pulverized into very small sand-like particles which substantially reduces the breaking action of the crusher.

An arraangement is provided for connecting the apparatus to the arm 54 of an excavating vehicle 56 for pivotting about a pivot 44 provided for the excavating bucket of the vehicle. A further pivotal fixing 46 is provided between the apparatus and the piston of the arm's bucket tilting ram 58. The apparatus is also connected for pivotting about an axis transverse to the pivot axis of the jaw portions 12, 20 comprising pivot pins 52 engaging in corresponding brackets on the cradle 36 and plate 48. The connecting arrangement comprises a mounting plate 48 pivotally mounted on the vehicle arm 54 and on the piston of the arm's bucket-tilting ram 58 by fixings 50, 46 respectively, and pivotally supporting attachment pivot pins 52 whose axes are parallel to the longitudinal axis of the apparatus. A further ram 53 is connected between the first member 10 (through the cradle 36) and the plate 48 to cause pivotal movement about the mounting pins 52 when desired. This means that the operation of the jaws is not restricted to movement in a substantially vertical plane. The jaws can operate at any angle making the attachment particularly suitable for loading crushed material directly into open topped vehicles or containers.

Various modifications may be made within the scope of the invention. For example the jaw portions 12, 20 may be differently shaped and may have a different arrangement of spikes 24, and projections other than spikes may be used. The apparatus shown in FIG. 3 has no spikes. The projection 26 could be differently shaped or a different method of preventing sideways or twisting movement could be used.

It should be realised that by providing the apparatus with its own jaw actuating ram and mounting this ram on one of the jaws, rather than by utilising, say, the bucket operating ram of the excavator which is mounted on the excavator arm, a relatively compact, lightweight and consequently inexpensive crushing apparatus in which all the crushing forces are resisted by the components of the apparatus and are not trasmitted to the arm of the excavator is provided.