GB2267887A

GB2267887A - Device for reversible attachment of a work tool to an earth moving machine.

Info

Publication number: GB2267887A
Application number: GB9312565A
Authority: GB
Inventors: Gerard Lacaze
Original assignee: SACMI SAVOYARDE
Current assignee: SACMI SAVOYARDE
Priority date: 1992-06-18
Filing date: 1993-06-18
Publication date: 1993-12-22
Anticipated expiration: 2013-06-18
Also published as: ITTO930438A0; GB2267887B; FR2692613A1; FR2692613B1; IT1261056B; ES2088343B1; GB9312565D0; BE1008200A3; DE4320101A1; ITTO930438A1; ES2088343A2; ES2088343R

Abstract

A device for the reversible attachment of a work tool, such as the bucket 1 of a mechanical shovel, is characterised in that the rear face 16 of the tool comprises two parallel and symmetrical sets I and II of fitting and coupling means, each comprising two coaxial pins 81, 82 forming filling elements, and a fixing bar 111, 112 aligned with and joining said pins and forming a coupling element. Locking mechanisms are shown in Figs 2, 3, 5 and 6. <IMAGE>

Description

2267887 DEVICE FOR THE AUTOMATIC AND REVERSIBLE ATTACHMENT AND REMOVAL OF

A WORK TOOL OF A MACHINE, PARTICULARLY AN EARTH MOVING MACHINE The present invention concerns the fitting of a tool at the end of the working element of a machine and it applies, more particularly, to the means for automatically fitting such a tool to the arm of an earth moving machine, such as an excavator, loader or mechanical shovel.

The prior art reveals a certain number of devices for the automatic attachment and removal of a work tool, such as a bucket or a shovel, fittable to a tool holder mounted, for example, on the articulated arm of an earth moving machine.

US patents 2 963 183, 3 512 665, 4 067 567 and French patent 1 504 892 may be cited in this respect, and, even more particularly, French patent 2 631 052 (88-06 248).

The technical solution provided-by the last cited publication gives full satisfaction by offering a device for automatic attachment and removal capable of providing an effective support on the tool holder, being able to withstand thrust or tensile stress and offering automatic compensation for structural clearance or clearance due to wear between the complementary parts of the tool and the tool holder.

The requirements of earth moving work have revealed that there were, however, limits on the use of such a device, because of the fact that it imposes a preferential direction of mounting on the tool which, in the case of a bucket, for example, is mounted either in the shovel position or in the reverse position.

In certain applications, such a preferential direction prevents the execution of special work, unless the tool is changed whenever required by the earth moving operation.

Thus, devices for automatically fitting tools do not allow excavations with vertical parallel walls and flat bottoms, as is for example necessarily required when digging vaults and tombs, to be executed precisely, in a rapid manner and without intervention by the operator.

In order to execute such an operation, it is necessary to have two tools which must be changed in order to execute each vertical face, as well as to execute the bottom.

Similarly, the remote execution of certain ditches, which pass under the foundation of a wall, without damaging said wall, cannot be envisaged properly with the articulated arm of a shovel, because of the prior orientation which is given to the tool.

The requirement to change the tool implies, as a consequence, having access to two items of equipment which must be capable of being changed on site. In practice, and because of the progress of the earth moving machinery, it is certain that, at the time of each necessary change, the desired tool is not immediately accessible to the operator.

In all cases, it is also necessary for the operator to intervene physically in order to effect the tool change, leading to significant fatigue, which is often the cause of accidents, sometimes serious ones.

one aim of the invention is to bridge the existing gap by making improvements to the device for automatic attachment and removal, of the type revealed in French patent application 2 631 052, so as to provide the means of enabling a single tool to be automatically and reversibly attached and removed, without subjecting the operator to hard work requiring significant physical effort.

Another aim of the invention is to provide a reversible character, whilst retaining the advantages of a device for automatic attachment and removal capable of ensuring compensation for structural clearance and clearance due to wear.

To this end, according to the invention there is provided a device for automatic and reversible attachment and removal of a work tool by the tool holder of an arm of a machine, particularly an earth moving machine, of the type comprising, firstly, on the rear face of the tool, fitting elements constituted by two coaxial pins extending horizontally at a distance from the rear face, and at least one coupling element forming a fixing bar extending horizontally and parallel at a distance from the rear face of the tool, and, secondly, on the tool holder, holding means which complement the fitting elements and are formed by housings which are open towards the top, and locking means for cooperating with the fixing bar, the locking means comprising a forked socket designed to receive the fixing bar and the horizontal plane of symmetry of which is situated at a distance from the bottom of the housings which is substantially equal to the distance separating the pins from the bar, and a wedge having an inclined face and driven by an actuator in order to engage or disengage it, through slots formed in the legs of the socket, behind the fixing bar, characterised in that the rear face of the tool comprises two parallel and symmetrical sets of f itting and coupling means, each comprising two coaxial pins forming fitting elements, and a fixing bar aligned with and joining said pins and forming a coupling element.

The invention also provides a reversible work tool, one of the faces of which comprises the two sets of fitting and coupling means of a device for automatic and reversible attachment and removal in accordance with the invention.

Various embodiments of the invention will now be described, by way of example only, with reference to the attached drawings, in which:

Figure 1 is an exploded view of one embodiment of the invention; Figure 2 is a section along the plane II-II of Figure 1; Figure 3 is a section along the broken line III-III of Figure 2; Figure 4 is a top view showing a further embodiment of the invention; Figures 5 and 6 are sectione levat ions along the lines V-V and VI-VI of Figure 4; Figure 7 is a sect ion/elevation of a tool using another embodiment of the invention; and Figure 8 is a diagram showing certain advantages of the invention.

Figure 1 shows, in diagrammatic form, the device of the invention designed to enable a tool 1 to be automatically attached and removed by a machine, particularly an earth moving machine. Such a machine comprises, for example, an articulated arm 3, at the end of which is fitted a tool holder 4, also linked to an orienting jack 5. The machine may be of any suitable type, such as a loader, an excavator or a mechanical shovel. Similarly, the tool 1, represented in the form of a bucket, is given by way of example only, the means of the invention also being fittable to a tool constituted by a shovel or to any other accessory.

The tool 1 comprises, on a supporting wall or face 6, generally designated as a rear face or wall, two upper fitting elements 7 which are constituted by two pins 8 supported by the cheeks 9. The pins 8 are coaxial and extend horizontally, at a distance from the supporting wall 6.

The tool 1 also comprises, at the lower portion of the supporting wall 6, a lower coupling element 10 forming a bar 11, known as a fixing bar, extending, horizontally and parallel, at a distance from the wall 6. As is revealed more precisely in Figure 2, the bar 11 is shaped to comprise, on its front face oriented to face the wall 6, a slope 12 inclined in a divergent manner from the top lla towards the bottom llb.

The tool holder 4 may be implemented in different possible ways to support the means of the invention which complement the elements 7 and 10 and to enable fitting at the end of the arm 3 and of the j ack 5. By way of example, the tool holder 4 comprises a supporting panel 13, on the rear face of which are attached rear side plates 14 which are parallel to each other. The side plates 14 delimit the bearings 15 and 16, designed for mounting the holder, via fixed pins, on the arm 3 and on the shaft 5 of the jack respectively.

On its front face, the panel 13 has two front side plates 17, the upper portions of which have means 18 of holding and of cooperating with the means 7. The means 18 are preferentially constituted by housings which are open from the top of the front side plates 17. The opening of each housing 18 is at least partly delimited by an inclined slope 19 assuming the function of a guide slope, able to direct the corresponding pin 8 appropriately into the housing 18 which takes the form of a half -cylindrical plain bearing. The thickness of the front side plates 17 is close to, but in all cases, less than the length of the pins 8 between the cheeks.

Together, the front side plates 17 and the panel 13 provide the support for a connection fork 20, the legs 21 of which extend horizontally in order to define a passage 22 between them. The horizontal plane of symmetry E of the passage 22 is arranged at a distance from the open housings 18 equal to the vertical measurement separating the coaxial pins 8 from the bar 11. The passage 22 has two sides which converge in the direction of the web 24, which extends parallel to the panel 13. The passage 22 is delimited so that its tranverse measurement, in the plane of the internal face of the web 24 is, in all cases, greater than the height separating the faces lla and llb of the bar 11.

The connection fork 20 is part of a locking element 25 which further comprises a wedge-shaped bolt 26, supported by an actuator 27 fitted to the tool holder 4. The actuator 27 is preferentially constituted by a power transformer, of the double-acting linear type, advantageously constituted by a hydraulic jack, the body 28 of which is mounted on the tool holder 4 in order to extend vertically. The jack 27 has a shaft 29 extending vertically and at the end of which is fitted the bolt 26 designed to be engaged with or disengaged from guide slots 30 provided in the legs 21 of the connection fork 20. The width of the slots 30, in transverse section perpendicular to the plane of the panel 13, is slightly greater than the thickness of the wedge 26. On its face oriented in the direction of the web 24, the wedge-shaped bolt 26 has a slope 31 inclined in a convergent manner in the direction of the end, at a gradient equal to that of the slope 12 of the bar 11.

In accordance with the invention, in the embodiment shown in Figures 1 to 3 the f itting 7 and coupling 11 means are constituted in the form of two parallel and symmetrical series I and II. The series I comprises the two coaxial pins 8 1 which are joined by a fixing bar 11 1 substantially conforming to the structural characteristics listed above. The series II is constituted by the fixing bar 11 2 at the ends of which are provided the pins 8 2 ' conforming to the characteristics of the pins 81r by being arranged in alignment with said pins 8 1 Thus, each series has a fixing bar which is aligned with two coaxial fitting pins 8 formed at the end and linked to the rear f ace 6 by the cheeks 9 1 or 9 2/ or their equivalent. According to an arrangement of the invention, which is shown in Figure 2, the fixing bars 11 and 11 2 are produced so as to comprise two slopes 12 and 12 2 which are undercut in two inclined orientations which converge from the rear face of the tool towards a median plane of symmetry x-x', parallel to the two series 1 and II.

The two bars also each have a transverse straight section which is greater than that of the coaxial pins 8, so as to delimit, for said pins and with respect to the cheeks 9, annular rims or shoulders which define the useful axial fitting length of each means 8.

As can be seen f rom Figure 1, the device of the invention enables the tool 1 to be fitted, oriented as illustrated in Figures 5 and 6, by ensuring that the pins 8 1 are engaged in the housings 18 in order to allow the bar 11 2 to fit in the passage 22 in which the bar is maintained by the engaging of the wedge 26, the slope 31 of which comes to cooperate with the slope 12 2 However, the tool 1 may also be fitted reversibly by being turned over on itself, so that the pins 8 2 fit in the housings 18 and the fixing bar 11 1 is positioned in the passage 22, where it is immobilised by the engaging of the wedge 26, the slope 31 of which is brought to cooperate with the slope 121 Thus, the same tool, such as a bucket, may be f itted in one direction or the other, in order to work, either as a shovel, or as mounted in reverse, without the operator being obliged to have two suitable tools and to execute physical fitting operations at the end of the arm 3. In fact, a tool is removed automatically by controlling the actuator 27 and the tool holder 4 may then be used to turn round the tool 1, so as to present the series I and II inversely to allow reversible automatic fitting.

Figures 4 to 6 show an embodiment in which each bar 11 1 or 11 2 is connected to the rear face 6 of the tool 1 via a plate 50 in which, in order to allow the passage of the wedge 26, a window 51 is provided which is partly defined or delimited by the slope 12 1 or 12 2 In this way, absorption of the load between the rear wall 6 and the bar 11, via the cheeks 9, may occur in order to reinforce the structure of the tool which may then, advantageously, be produced with shaped plates of reduced thickness in order to lessen the weight without reducing its mechanical strength characteristics.

Figure 7 shows an advantageous arrangement consisting of using, for the two series I and II, common cheeks 52 which, with the plates 50, enable a sort of load absorbtion frame to be constituted in both the vertical plane and the horizontal plane. Figure 7 also shows that the plates 50 may each be constituted by a small bar 53 and by a second small bar 54 forming an integral part of the bar and the wall 6 respectively. In this way, it is possible to produce, practically, rapidly and at a low cost, a tool such as 1, whilst observing the requirement for alignment and parallelism between the series I and II which form intergrdl parts of the cheeks 52.

The linking of the cheeks 52, particularly by welding to the wall 6, enables them to be placed facing each other covering the small bars 53 and 54 of each plate 50 and to fix them by welding, whilst assuring that the series I and II are in alignment parallel to the wall 6, without a further machining operation.

The example in Figure 7 illustrates a tool of the shovel type which may be fitted in one direction or the other, reversibly, to the arm 3 of a machine 60 which may be used, as illustrated in Figure 8, to produce excavations F with vertical walls 61 and orthogonal flat bottom 62, with depth and width characteristics which take account of the displacement diagram E likely to be given to the tool by the structure of the articulated arm 3.

The property of reversible assembly also enables excavations to be produced starting from the supporting ground and passing under an obstacle, such as a wall, a small wall or a low wall, without having to partially demolish said wall.

Claims

1 A device for automatic and reversible attachment and removal of a work tool by the tool holder of an arm of a machine, particularly an earth moving machine, of the type comprising, firstly, on the rear face of the tool, fitting elements constituted by two coaxial pins extending horizontally at a distance from the rear face, and at least one coupling element forming a fixing bar extending horizontally and parallel at a distance from the rear face of the tool, and, secondly, on the tool holder, holding means which complement the fitting elements and are formed by housings which are open towards the top, and locking means for cooperating with the fixing bar, the locking means comprising a forked socket designed to receive the fixing bar and the horizontal plane of symmetry of which is situated at a distance from the bottom of the housings which is substantially equal to the distance separating the pins from the bar, and a wedge having an inclined face and driven by an actuator in order to engage or disengage it, through slots formed in the legs of the socket, behind the fixing bar, characterised in that the rear face of the tool comprises two parallel and symmetrical sets of fitting and coupling means, each comprising two coaxial pins forming fitting elements, and a fixing bar aligned with and joining said pins and forming a coupling element.

2. A device according to claim 1, in which the f ixing bars of the two sets have, facing the rear face of the tool, respective sloping faces which are inclined and undercut in directions converging away from said rear face towards a median plane of symmetry parallel to the two sets.

3. A device according to claim 1 or 2, in which the bars are each rigidly. .fixed to the rear face of the tool by means of a plate having an opening for the passage of the wedge and partly defined by the undercut sloping face.

4. A device according to claim 3, in which the plate is constituted by two small bars (53, 54), rigid with the bar and the rear face respectively, and joined together by welding.

5. A device according to any one of claims 1 to 3, in which the bars have a transverse straight section which is greater than that of the pins which each of them forms at the end and which are supported by cheeks rigid with the rear face of the tool.

6. A device according to claim 5, in which the cheeks are common to the pins of the two sets and, with the plates, constitute a load absorption frame in relation to the rear face of the tool.

7. A device according to claim 1, substantially as described with reference to Figures 1 to 3, Figures 4 to 6, or Figure 7 of the accompanying drawings.

8. A reversible tool, particularly for earth moving machines, in which the rear of the tool is provided with the two sets of fitting and coupling means of a device according to any one of the preceding claims.