GB2083110A - Ripper Attachment for excavator - Google Patents

Abstract

In order to provide an articulated arm bucket excavator 10-11-18 with a remotely controlled ripper attachment, a ripper tooth 20 is rigidly secured on the web of a link 17 having end mounting sleeves so that the conventional bucket-tipping link can be replaced by the ripper link (17,20). In use the ripper link (17,20) connects the crowd arm (16) to the excavator bucket (18) so that the ripper (20) and bucket (18) are simultaneously attached to the end of the excavator arm (10,11). In the fully "crowded" position of the bucket (18) the ripper (20) is in its operational position for ripping the ground (24). Thus, bucket (18) or ripper (20) can be selected at will from the cab of the excavator by movement of the crowd arm (16). <IMAGE>

Description

SPECIFICATION Ripper attachment for excavator The present invention relates to a ripper link for use on an excavator provided with an articulated excavation arm.

The excavators are fitted with a hydraulicallydriven articulated excavation arm to the end of which may be fitted any one of a number of implements which include buckets, fork lift tines, rippers and blades. The excavator may be used for excavating material to form slots or holes in the ground.

Thus, a bucket is often fitted to the arm in order to scoop out soft material. However, where the ground is relatively hard, it is impossible to use the bucket in the way described. In this case, the bucket may be detached from the arm and replaced with a ripping tool or ripper tooth which has a sharp point capable of penetration into the hard ground to break it up.

Then, the bucket may be refitted to the arm and used to clear away the material broken up using the ripper.

To overcome the problem of the time and effort involved in changing implements fitted to the arm with conventional techniques, a system of quickchange implements has been devised. This system enabled the machine operator to swap implements with less effort than was required when changing implements fitted with the conventional technique.

However, it still required the operator to dismount his machine to effect the change.

A further development to help avoid the difficulty of swapping implements was made when a combined ripper-bucket was developed. This combined implement comprised a ripper hook fitted to the arm in the usual way, though with the added feature of a bucket pivotally mounted to the arm adjacent to and when desired in registration with the ripper. The ripper and the bucket were arranged so that in one mode of operation the ripper could be secured within the bucket, thus enabling the use of the bucket in the usual way. If, however, it was desired to use the ripper as such, a pin which was provided in the implement could be removed allowing the bucket to swing freely about a pivotal mount free of the ripper.

Thus, in this second mode of operation, as the implement was brought into engagement with the ground to be excavated the bucket, on engaging the ground, swung away exposing the ripper for engagement with the ground to be broken up. Once the breaking was complete the pin could be reengaged into the implement allowing the operator to use the bucket in the normal way to collect the broken material.

The disadvantage of this latter adaptation was that the operator still had to dismount his machine whenever he wished to change the mode of operation of the implement.

Prior art articulated arms of this type usually comprise a rigid boom pivotally mounted to a prime mover which may be a tracked or tyred vehicle. A dipper stick is pivotally mounted at an end portion thereof to an end portion of the free end of the boom, the angular disposition of the dipper stick in relation to the boom being controlled by a hydraulic cylinder referred to in the trade as a "stick cylinder".

The implement to be used in conjunction with the articulated arm is secured to the free end of the dipper stick. In order to control the angle of the implement in relation to the dipper stick, a hydraulic cylinder termed a "bucket cylinder" or "crowd" cylinder is provided. At one end the cylinder is secured to the dipper stick while at the other it is pivotally secured to a pivotable linkage which is termed "a crowd arm". To complete the connection to the bucket, a "tipping link" (or "crowd link") is pivotally secured at one end to the crowd arm and at the other end to a point on the bucket. Accordingly, operation of the crowd cylinder which works through the crowd arm and the tipping link changes the angle of the bucket in relation to the dipper sticks.A more complete appreciation of the interrelation between the various integers described above may be gained by reference to Figures 1 to 3 of the accompanying drawings which are discussed later in the specification in more detail.

The present invention seeks to mitigate some of the disadvantages of the prior art described above and in particular to provide an improvement or adaptation of existing excavation machinery to provide a ripper and a bucket or like implement on the same excavation arm simultaneously, the use of which may be achieved without the operator dismounting his machine.

The present invention relates to an appendage in the form of a ripper which replaces the tipping link.

According to one aspect ofthe present invention there is provided a ripper link for use with an articulated excavation arm, which comprises first securing means at a first end portion to allow pivotal securing of the link to a crowd arm provided on the excavation arm, second securing means at a second end portion to allow pivotal securing of the link to an implement pivotally attached to the excavation arm, and a pointed ripping head connected between said first and second securing means and extending away from a line joining said first and second securing means; the dimensions of the ripper link being such that when the implement is in relatively crowded positions the ripping head projects for engaging and ripping hard ground.

Preferably, the angle of the point of the ripping head is such that the point lies substantially parallel with the line joining the two connection points of the ripper link.

The ripping head may be provided with a detachable boot or tip made of a relatively hardened material to reduce the wear of the ripping head in use.

The ripper link may be installed on an excavator in place of the conventional tipping link. A conventional "ripper tooth" supplied as an implement for attachment to the end of the dipper stick cannot be attached between the crowd arm and the implement (as in the case of the ripper link of the present invention) since the mounting points are the wrong size. In general, presently available ripper tooth implements do not have suitable mounting points to enable them to be used in place of a conventional tipping link.

In the drawings Figure 1 to 3 illustrate the prior art.

An embodiment ofthe invention is described in conjunction with Figures 4 and 5.

Figure 1 (prior art) shows a backhoe loader fitted with a backhoe bucket and a loader bucket, Figure 2 (prior art) shows a portion of an excavator also fitted with a backhoe bucket, Figure 3 (prior art) shows a portion of a face shovel, Figure 4 shows a boom which may be fitted to any one of the three machines described above and which includes a ripper link embodying the invention, and Figure 5 is a perspective view of a ripper link embodying the invention.

Referring first to Figures 1,2 and 3 it can be seen that in each instance the apparatuses include a boom 10 pivotally connected to a dipper stick 11 which is in turn connected pivotally to some type of implement. In each case a boom cylinder 12 is fitted to the machine to effect controlled vertical movement of the boom about a pivot point on the machine. Further, in each case a second hydraulic cylinder or stick cylinder 13 is fitted between the boom and the dipper stick to achieve controlled pivotal movement of the dipper stick about a point 14 on the boom.

Again in each case a bucket or crowd cylinder 15 is fitted to the dipper stick to facilitate pivotal movement of the bucket or like implement about a point 19 on the dipper stick. It should be noted that a crowd arm 16 is pivotally connected to the dipper stick and arranged to transmit the reciprocating motion generated by the crowd cylinder via tipping link 17 to the implement 18.

A preferred embodiment of the present invention as illustrated in Figure 4 shows the provision of a ripping head 20 on tipping link 17. This ripping head is brought into play by "crowding" bucket 18 by extending cylinder 15, thus exposing the ripping head for horizontal movement thereof through the material to be broken up. For convenience the combination of the tipping link provided with a ripping head may be termed a ripper link.

Should relatively vertical ripping be required, for example in scraping of a vertical wall, less crowding of the bucket may be provided by adjusting the crowd cylinder appropriately and the ripping head may then be moved vertically to scrape such a wall.

Figure 4 illustrates with ground level line 24 that in the crowded position of bucket 18 it is clear that in this embodiment ripping head 20 may readily engage hardened ground below the bucket.

It should be noted that the ripping link of the invention can be used with any one of the machines described or any machine of similar type so long as a conventional tipping link is presently being used.

Finally, Figure 5 is a perspective view of a ripper link embodying the invention. In particular, this Fig ure illustrates the front sleeve 21 and rear sleeve 22 by which the link is connected to the implement and crowd arm respectively. Further, web portion 23 which is welded to the respective sleeves, is also iilustrated. This Figure shows more clearly the shape of the preferred form of the ripping head 20 as illustrated in earlier drawings. Also, a hardened boot 25 is shown in its position fitted to the ripping head. In this preferred form of the invention the ripping head was butt-welded to the underside of web portion 23.

In the alternative, apertures may be provided in web 23 and tabs provided on ripping head 20 for engagement within the apertures to enable the provision of a stronger welded joint between the two -' members. Of course, if desired the ripper link could be cast in one piece.

The material from which this preferred embodiment is made is an appropriately hardened steel.

The installation of the ripper link of the present invention is shown in greater detail in FigureS. First the pivot pin at each end of the tipping link 17 is withdrawn and the tipping link removed. Then a ripper link is inserted between opposed flanges 26 and 26' at the free end of the crowd arm 1 so that circular apertures 27 line up with the rear sleeve 22.

Finally the pivot pin 28 is passed through the apertures 27 and sleeve 22 and secured in place by means of a nut attached to the end of the pivot pin.

Similarly, the other end of the ripper link is attached by means of a pivot pin to flanges (analogous to flanges 26 and 26' of the crowd arm) provided on the bucket 18.

Thus, it will be clear that a conventional ripper tooth implement could not be employed in the practice of the present invention as it would lack suitable means for securing between the bucket and the crowd arm.

Claims (5)

1. A ripper link for use with an articulated excavation arm, which comprises first securing means at a first end portion to allow pivotal securing of the link to a crowd arm provided on the excavation arm, second securing means at a second end portion to allow pivotal securing of the link to an implement pivotally attached to the excavation arm, and a pointed ripping head connected between said first and second securing means and extending away from a line joining said first and second securing means; the dimensions of the ripper link being such that when the implement is in relatively crowded positions the ripping head projects for engaging and ripping hard ground.

2. A ripper link according to claim 1, wherein the ripping head is so dimensioned that its pointed end points in a direction substantially parallel with the line joining the first and second securing means.

3. A ripper link according to any preceding claim, wherein the pointed end of the ripping head is in the form of a detachable tip of a material harder than tbe rest of the link.

4. A ripper link according to any preceding claim, wherein the first and second securing means each comprise sleeve means for accepting a pivot pin, the ends of each sleeve means being separated by a distance such as to enable the first securing means to be secured to the crowd arm and to enable the sec ond securing means to be secured to the implement.

5. An excavator including a ripper link according to any preceding claim, which further comprises a dipper stick, a crowd arm pivotally attached at one end thereof to the dipper stick, and an implement pivotally attached to the dipper stick; the ripper link being secured at the first securing means to the other end of the crowd arm and being secured at the second securing means to the implement.

6 A ripper link or excavator including a ripper link substantially as described in conjunction with Figures 4 and 5.