WO1991015635A1

WO1991015635A1 - Rock tongs for excavators

Info

Publication number: WO1991015635A1
Application number: PCT/CH1990/000090
Authority: WO
Inventors: Peter Ruf
Original assignee: Schweisswerk Gischig Ag
Priority date: 1990-04-04
Filing date: 1990-04-04
Publication date: 1991-10-17
Also published as: JPH04506237A

Abstract

These rock tongs for excavators solve an old problem, namely that large rocks which are exposed when earth is removed cannot be lifted with the normal excavator shovel. This problem is solved in the present patent with two additional gripper arms or tongs parts (1), which can be mounted on the normal excavator shovel (2) and controlled hydraulically. As a result, very large rocks exposed in the course of excavation can be gripped in a tongs-like manner and removed.

Description

S T E I N Z A N G E N U E R B A G G E R

The object of the present invention was to solve the following problem:

With normal excavator shovels, it is difficult to grasp larger stones. Stones or boulders can only be moved from one place to another with great effort. They can hardly be gripped with a normal excavator shovel. If the stone is to be lifted out of a trench, problems always arise. However, the exact placement of such stones or boulders always presents difficulties without a special device.

Larger stones or boulders must be able to be lifted, moved and placed without any problems.

So far, the problem has been avoided by first crushing large stones and then moving them with a sufficiently large shovel or with muscle power. This is a tedious, cumbersome, and time-consuming task that has to be neglected when placing large embankment or decorative stones. Here only the method of attaching the stone to the dipper stick with a rope comes into question. The great risk of slipping is combined with the great expenditure of time. There is also the option of using a shovel designed for gravel mining. It consists of two blade halves that complement each other and can be opened and closed like a pair of pliers. Unfortunately, this shovel poorly suited for excavation work. In addition, the size of the liftable stones is greatly limited by the maximum opening angle of the blade.

According to the current state of the art, the following three solution variants are made:

1 . Variant:

An already known possibility is to attach an additional gripper operated by the hydraulic system of the machine to the dipper arm itself. This means that it is no longer necessary for the stone to be loaded and fixed on the excavator bucket using other tools. The additional gripper can now exert the clamping effect that is required to lift stones or boulders. Unfortunately, with this variant, the gripper has to be traversed by hand in synchronism with the bucket, which in practice poses problems and considerably complicates the control.

2nd variant:

The spoon ^" is replaced by a special stone gripper. It essentially consists of three to five circularly arranged, hydraulically operated arms. The stones or boulders can thus be gripped and clamped. Unfortunately, such a special gripper is possible with its arms Digging trenches or holes completely, so it only makes sense for work where practically only stones have to be lifted, otherwise a constant reassembly of this stone fer to the normal excavator bucket and vice versa would not be debatable.

The inventor of the present patent was able to overcome these disadvantages in a clever manner. This is because he significantly improved variant 1 by replacing the individual gripper arm with two gripper arms, which are also no longer attached to the dipper arm 3 but to the bucket 2. By virtue of the fact that these gripper arms 1 are attached to the movable part , namely attached to the blade, it is achieved that they automatically participate in all movements with the blade 2 and no longer have to be tracked separately. In addition, they will adapt to the shape of the stone. Since they are hydraulically controlled, they will change the angle of rotation until they hold the stone with the necessary pressure. The left and right rotary arms therefore do not need to have the same angle of rotation. These two gripper arms 1 thus form a pair of pliers with the shovel 2, which offer a much better guarantee than the variant 1 that the stones do not fall out immediately. These gripping arms 1 are thus a useful addition to the conventional excavator buckets 2.

The advantage of this invention compared to variant 2 is that we have a universal solution here that is suitable for both excavating and picking up stones.

FIG. 1 shows a side view on which the gripper arms 1 attached to the excavator bucket can be seen. Figure 2 shows the whole arrangement from above. The basic innovations are now as follows: due to the optimal arrangement of the two gripper arms 1 and a corresponding construction, the stone tongs arms 1 can be pivoted completely upwards, so that the stone tongs 1 can remain on the shovel even during normal excavation work and do not represent a disability. The assembly of the stone tongs 1 on the rotating part (blade) 2 ensures that the stone tongs arms 1 follow all the movements of the blade 2. With the patent described here, the inventor has succeeded in finding a practical, practical and at the same time safe and comfortable solution to the problems mentioned at the beginning. The simple construction method used at the same time guarantees a cost-effective production. Because of this practicality mentioned, this stone pliers will find a quick spread.

Claims

PATENT CLAIMS

.. Backhoe, with a bucket which is pivotally connected to a dipper stick and with two gripper arms which can be pivoted independently of one another in order to press a boulder into the bucket, characterized in that each of the gripper arms by one with respect to the Spoon fixed axis is pivotable.

2. Backhoe according to claim 1, in which each of the two gripping arms can be pivoted by a hydraulic cylinder-piston unit, characterized in that the cylinder-piston units are each supported on the bucket or on a part rigidly connected thereto.