EP0625613B1 - Coupling device for attaching an implement to an arm of an excavator - Google Patents

Abstract

The invention relates to a device for interchangeably attaching an implement to the front end of an arm 3 of an excavator. The implement is provided with a first, transversely running rod 12 as well as with a first locking element. The exchange device 1 is provided with a first recess 7, by means of which the exchange device 1 can be slipped onto the first rod 12, as well as with a second, displaceable locking element which can be brought into engagement with the first locking element and as a result the implement is held by positive locking on the exchange device 1. In order to provide a technically simple and universally usable device for interchangeably attaching an implement to the front part of an arm of an excavator, it is proposed with the invention that the first locking element of the implement be a second rod 12' parallel to the first rod 12, that the exchange device 1 be capable of being slipped onto the second rod 12', and that the second, displaceable locking element block the escape of the second rod 12' from the second recess 7' in a positive-locking manner in the locking state. <IMAGE>

Description

The invention relates to a device for the interchangeable attachment of a tool-like attachment to the front end of an excavator arm of an excavator, the attachment with two parallel, transverse rods, the exchange device with a first pair of recesses, by means of which the exchange device can be pushed onto the first rod, and with a second pair of recesses, by means of which the exchange device can be pushed onto the second rod, and finally with two displaceable locking elements, which in the locked state block the exit of the second rod from the second pair of recesses in a form-fitting manner.

With the fastening device according to the invention, a wide variety of tools can be attached to the front end of an excavator arm, for example digging vessels (spoons or grabs) or other attachments, such as hammers. Each excavator usually has different types of attachments available depending on the application.

In the basic version of an excavator bucket, this has two bolt receptacles in a row. A bolt is then inserted therethrough, so that the bucket is pivotably arranged on a corresponding mechanism of the excavator arm. In this standard version, the spoons are replaced by hand using the appropriate auxiliary personnel, by removing the corresponding two bolts, so that the spoon that is no longer required is released, and then a new spoon or a gripper or other attachment can be added by inserting the to attach two bolts to the excavator arm. Although this version is inexpensive due to the bolt attachment, it is cumbersome to use because the excavator operator cannot change the bucket himself, but only with the help of a second person. With a frequent change, this is cumbersome and uneconomical.

To remedy this problem, there are automatic mounting devices for the attachments. With these it is possible for the excavator operator to change the appropriate bucket without the help of an additional person. For this purpose, the receiving device is arranged pivotably at the front end of the excavator arm. This device has a slot-shaped recess at one end, by means of which the receiving device can be pushed onto a corresponding transverse pin of the spoon. With the other end, the receiving device extends a bolt in its longitudinal center line, which engages in a corresponding opening in the spoon. The bolt is conical and has a certain reserve play. This conical bolt is thus pressed into the opening, thus creating a positive connection between the receiving device and the spoon. A disadvantage of this is that the corresponding add-on parts have to be converted so that the receiving device can be adapted. This is done in such a way that the old standard equipment is removed and replaced with a new adapter device. If several attachments are assigned to the excavator (which is the rule), this is very expensive because each attachment has to be converted. In addition, the known adapter is subject to a relatively large amount of wear. Another disadvantage is that the respective spoon can only be picked up in one direction, that is, either only as a spoon or as a spoon. It is therefore not possible to change one and the same spoon from a backhoe to a backhoe and vice versa.

EP-A-0 506 604 discloses a quick coupling for temporarily mounting work tools on a boom of a construction machine of the type specified at the outset. For this purpose, the work tool has two parallel and transverse rods, which are arranged in a kind of frame made of two side frame walls. The quick coupling has two half-shells corresponding to the rods, which are formed in two box walls of a box. The quick coupling works in such a way that the one half-shell is first pushed onto the one rod, in order to then slide the other half-shell onto the second rod after the rotary coupling has rotated around the rod as the axis of rotation. The positive locking takes place by means of a slide. This is under the force of a spring and is moved into the locking position by means of this spring in such a way that the rod cannot emerge from the half-shell. When changing the work tool, the slide is moved backwards against the force of the spring by means of a hand lever, so that the rod can emerge from its half-shell. As an alternative to the hand lever, a pneumatically or hydraulically operable slide unlocking and locking device can also be provided. However, it is not described how this facility should work.

WO-A-85/04440 discloses a device for exchangeably attaching a tool-like attachment to the front end of an excavator arm of an excavator. For this purpose, the attachment has a transverse rod between two side walls, in which two openings are also formed. The excavator arm has a pair of recesses at the front end, which is formed in pairs of side plates of the changing device and by means of which the quick coupling can be pushed onto the transverse rod. The final fixation of the attachment on the excavator arm is achieved by inserting a bolt through the openings in the attachment part and through openings in the excavator arm corresponding to it. The pair of recesses of the quick coupling has such a length that attachments with different distances between the crossbar and the openings can be accommodated. As a length compensation, the quick coupling has an eccentric in the area of the openings.

The invention has for its object to provide a device for interchangeably attaching a tool-like attachment to the front end of an excavator arm of an excavator of the type specified above, which works trouble-free with regard to the displacement of the locking elements.

As a technical solution , the invention proposes that an omega-shaped bracket is provided for moving the two locking elements, which is fixed to the respective locking element with its outwardly directed legs.

This creates a device for the interchangeable attachment of a tool-like attachment to the front end of an excavator arm of an excavator, which works largely trouble-free with regard to the displaceability of the locking elements. The fastening device or connecting device according to the invention of the displacement device on the two locking elements by means of the omega-shaped bracket has the advantage that the specially designed bracket creates a certain amount of play in the connecting mechanism, which reduces malfunctions to a minimum due to the forces occurring . In addition, the omega-shaped bracket has a certain guiding and spring function, which also minimizes the forces that occur. For example, no tilting occurs during the displacement movement of the locking elements.

An advantageous development proposes that the bracket consists of two Z-shaped bracket elements which are attached to one another in a dot-shaped manner in the region of the central axis of the device and which are fixed to the respective locking element with the other legs. This enables simple installation in the device.

A further development suggests that a double-acting cylinder / piston unit is provided for displacement. This can preferably be operated hydraulically and represents a technically simple and reliable way of moving the wedges.

In a further development of the replacement device according to the invention, the two pairs of recesses are aligned with respect to one another in such a way that the second pair of recesses can be pushed onto the second rod if the first pair of recesses has been pushed onto the first rod and held in place by a positive fit after a pivoting movement is. This has the advantage that the pivoting movement creates a positive connection between the first recess and the first rod such that additional locking elements in the region of the first recess can be dispensed with. This is a constructive simplification.

In a further development of the recesses, it is proposed that the first pair of recesses be of such a length that attachments with differently spaced rods can be fastened with the same replacement device. This allows add-on parts with different axial dimensions of the rods to be accommodated with regard to their spacing.

A further development suggests that the locking elements are wedges. This represents a technically simple possibility for locking the replacement device on the corresponding add-on part, in that the wedges are preferably extended hydraulically in a simple manner. The wedge shape also ensures that the locking elements rest firmly on the associated rod and a game is avoided, which could lead to increased wear. The locking and unlocking of the wedges can be controlled electrically and hydraulically from the cab and is done at the push of a button. Unlocking can be signaled to the driver by two red control lamps and an acoustic buzzer. Unintentional unlocking is therefore impossible. Preferably, the locking wedges are always under pressure so that wear on the wedges is minimal.

A further development suggests that a spring is additionally provided, which forcibly displaces the locking elements into the locking position. This additional spring forms a kind of redundancy if the cylinder / piston unit should ever be defective. In this case, the wedges are held in their locking position by the spring pressure, so that the attachment cannot fall off the fastening device.

A further development suggests that the attachment with its two rods can be attached to the exchange device both from one side and from the other side. This means that the original bucket can be used as a bucket or a bucket without additional conversion measures, which further increases the possible uses.

Finally, it is proposed in a further development that the replacement device consists of an upper part for the articulation on the excavator arm and a lower part for the recesses and for the displaceable locking element. This represents a structurally simple structure of the replacement device.

Fig. 1

eine schematische Seitenansicht der Befestigungsvorrichtung;

Fig. 2

eine schematische Draufsicht auf die Befestigungsvorrichtung in Fig. 1;

Fig. 3a bis d

die Anwendung der Befestigungsvorrichtung in Fig. 1 und 2 bei einem Tieflöffel, wobei die verschiedenen Stufen des Befestigungsvorganges dargestellt sind;

Fig. 4a bis d

die Anwendung der Befestigungsvorrichtung in Fig. 1 und 2 bei einem Hochlöffel, bei dem es sich um den um 180° gedrehten Tieflöffel in Fig. 3a bis d handelt und wobei die verschiedenen Stufen des Befestigungsvorganges dargestellt sind.

An exemplary embodiment of a device according to the invention for the interchangeable fastening of a digging vessel at the front end of an excavator arm of an excavator is described below with reference to the drawings. In these shows:

Fig. 1

a schematic side view of the fastening device;

Fig. 2

is a schematic plan view of the fastening device in Fig. 1;

3a to d

the application of the fastening device in Figures 1 and 2 in a bucket, the different stages of the fastening process are shown.

4a to d

the application of the fastening device in Fig. 1 and 2 in a spoon, which is the 180 ° rotated bucket in Fig. 3a to d and the different stages of the fastening process are shown.

The interchangeable device 1 for the interchangeable fastening of a digging vessel 2 at the front end of an excavator arm 3 of an excavator consists of an upper part 4 'and a lower part 4 ". The upper part 4' is used for articulation on the excavator arm 3 while the lower part 4 "serves for the actual fastening of the digging vessel 2 to the excavator arm 3. As can be seen in FIGS. 1 and 2, the upper part 4 'and the lower part 4" consist of pairs of side elements which are connected to one another by corresponding transverse elements.

The upper part 4 'has a bore 5 at each of the two ends. The upper part 4 'is articulated directly to the front end of the excavator arm 3 by means of one bore 5, while a coupling 6 in the form of a double lever is articulated in the other bore 5. The other end of this coupling 6 is articulated on the excavator arm 3, while a pivoting device, in particular in the form of a cylinder / piston unit, acts on the pivot point between the two levers of the coupling 6. This is indicated by dash-dotted lines in FIGS. 3 and 4. As a result, the exchange device 1 and thus the grave vessel 2 attached to it can be pivoted.

The lower part 4 "has slot-shaped recesses 7, 7 'formed in the side elements. The recess 7 extends essentially in the longitudinal direction of the exchange device and the recess 7' at an acute angle transversely thereto, as can be seen in particular in FIG. 1 and the purpose of these different orientations of the recesses 7, 7 'will be described in connection with Figures 3 and 4. The two recesses 7' are each assigned a displaceable wedge 8 such that in the locking position the wedges 8 into the recesses 7 ' The wedges 8 are actuated by means of a schematically indicated hydraulic cylinder / piston unit 9. In addition, the wedges 8 are forced into the locking position by means of a spring 10 which is only indicated schematically The mechanical connection between the cylinder / piston unit 9 and the wedges 8 are carried out via a bracket 11, as can best be seen in Fig. 2. This B gel 11 is formed shaped essentially omega-and consists of two bracket members 11 ', 11 ", the Z-shape are formed substantially in each case, wherein the two legs at right angles from the base member and projecting in opposite directions. While the one corresponding leg of the two bracket elements 11 ', 11 "are connected to one another in a substantially punctiform manner in the region of the piston axis, the other, outwardly directed legs of the two bracket elements 11', 11" engage in indicated wedge holders and which carry the wedges 8 establish the operative connection. This type of mechanical connection between the cylinder / piston unit 9 and the wedges 8 creates a flexible structure which gives the bracket 11 a certain amount of play within the exchange device 1, which counteracts deterioration in wear.

The grave vessel 2 finally has two transverse rods 12, 12 'on the top, as are known from standard grave vessels. The diameters of these rods 12, 12 'correspond to the widths of the recesses 7, 7'.

The exchange device 1 works as follows:

While a backhoe bucket is shown in FIGS. 3a to d, a backhoe bucket is shown in FIGS. 4a to d. These two applications do not differ in terms of the basic principle, only the orientation of the grave vessel 2 is different.

In the embodiment in FIGS. 3a to d (backhoe bucket), it can be seen in FIG. 3a how the excavator arm 3 is located above the digging vessel 2 without any attachment having already taken place. The excavator arm 3 is thus intended to accommodate the digging vessel 2. For this purpose, the exchange device 1 is transferred into the extended position by means of the coupling 6 and the recess 7 is pushed onto the rod 12, as can be seen in FIG. 3b. In the next step (FIG. 3c), the exchange device 1 is then pivoted by actuating the coupling 6 in such a way that the second recess 7 'is pushed onto the rod 12'. The center of rotation is the rod 12. The wedges 8 are then moved into the recess 7 'by means of the cylinder / piston unit 9, so that the rod 12' can no longer emerge from the recess 7 'by means of a corresponding form fit (see also FIG . 1). At the same time, the wedges 8 are held in this locking position by the spring 10, even if the cylinder / piston unit 9 should fail. In this pivoting position, as shown in Fig. 3c and in Fig. 1, the rod 12 can not come out of this recess 7 due to the corresponding orientation of the recess 7, so that overall a positive connection for attaching the digging vessel 2 to the replacement device 1 is created. This makes it possible to operate the burial vessel 2, i.e. to pivot, as shown in Fig. 3d. In addition, the recess 7 is lengthened such that rods 12, 12 ′ at different distances can be received with one and the same exchange device 1. Correspondingly, the differently positioned center points of rods 12 are drawn in.

The embodiment in FIGS. 4a to d differs from the embodiment in FIGS. 3a to d only in that the same grave vessel 2 is rotated through 180 ° without any structural changes being made either to the exchange device 1 or to the grave vessel 2 had to. The attachment is carried out in a manner corresponding to that described in connection with the embodiment in FIGS. 3a to d has been.

Reference list

1

Exchange device

2nd

Grave vessel

3rd

Excavator arm

4 '

Top

4 "

Lower part

5

drilling

6

Paddock

7, 7 '

Recess

8th

wedge

9

Cylinder / piston unit

10th

feather

11

hanger

11 ', 11 "

Bracket element

12, 12 '

pole

Claims (9)

1. Device for interchangeable fixing of a tool-like attachment to the front end of an excavator arm (3) of an excavator, the attachment having two transverse rods (12) parallel to each other, the interchange device (1) having a first pair of recesses (7) by means of which the interchange device (1) can be pushed onto the first rod (12), and a second pair of recesses (7') by means of which the interchange device (1) can be pushed onto the second rod (12'), and finally two sliding locking elements which in their locked state tightly block the emergence of the second rod (12') from the second pair of recesses (7'),
   characterised in that
   to slide the two locking elements, an omega-shaped bracket (11) is provided which is attached by its outward-pointing legs to each locking element.
2. Device according to claim 1, characterised in that the bracket (11) consists of two Z-shaped bracket elements (11', 11'') which are fastened together by one leg essentially at a point in the area of the centre axis of the device and which are attached by the other leg to the respective locking element.
3. Device according to any of the previous claims, characterised in that a double acting cylinder/piston unit (9) is provided for the movement.
4. Device according to any of the previous claims, characterised in that the two recess pairs (7, 7') are aligned to each other such that the second recess pair (7') can be pushed onto the second rod (12') when the first recess pair (7) has first been pushed onto the first rod (12) and, after a swivel movement, held there by an interference fit.
5. Device according to any of the previous claims, characterised in that the first pair of recesses (7) are sufficiently long that attachments with rods at different spacings (12, 12') can be attached with the same interchange device (1).
6. Device according to any of the previous claims, characterised in that the locking elements are wedges (8).
7. Device according to any of the previous claims, characterised in that a spring (10) is also provided which forces the locking elements into their locking position.
8. Device according to any of the previous claims, characterised in that the attachment can be fastened with its two rods (12, 12') on either side of the interchange device (1).
9. Device according to any of the previous claims, characterised in that the interchange device (1) consists of an upper part (4') for the coupling on the excavator arm (3) and a lower part (4") for the recesses (7, 7') and the sliding locking element.

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