EP0609176B1 - Coupling device for coupling an implement to a back-hoe arm - Google Patents

Abstract

The coupling comprises a male end piece (1) intended to be coupled to the end of the arm of the machine, and a female piece (2) integral with a tool. These two pieces are engaged in one another by means of a ramp system (4, 5, 14, 15) which presses the two pieces against each other. This engagement is maintained without play by a wedge-shaped bolt (24) urged by a spring (31) acting on a crank (297) equipped with a pawl (32, 33). The bolt is further mounted on a sliding shaft (26) making it possible laterally and vertically to move the bolt away from the limit stop (22), the bolt being fastened to a finger (38) to allow the engagement and disengagement of the pieces (1, 2) of the device. <IMAGE>

Description

The subject of the present invention is a device for rapidly fixing a tool to the end of a construction machine arm, comprising a terminal piece intended to be fixed to the end of said arm and provided with two pairs of lateral projections. having ramps coming to hang on corresponding ramps of two pairs of corresponding lateral projections formed on the opposite faces of two parallel walls of the tool, and locking means exerting and maintaining an engagement thrust on said projections of so as to apply the tool against the end piece and keep it applied.

Such a device, known as a quick coupler, is described in the applicant's patent application EP 0 467 837. In this patent application, three locking devices are described which simultaneously provide compensation for the play due to wear by exerting a permanent engagement thrust on the hooking projections. The first two devices described use locking parts which it is necessary to remove when fixing and removing the tool at the end of the arm of the machine. These locking parts, as well as the screws which keep them under tension, are also exposed to shocks during the working of the machine. The third device, intended to be actuated by means of an unlocking cylinder, did not give the expected results. It is also delicate and bulky.

The object of the present invention is to produce a quick fixing device comprising locking means with no parts to disassemble when attaching or removing the tool at the end of the arm of the construction machine, easy to use, well protected against impact and making the best use of available space .

The device according to the invention is characterized in that the locking means comprise a lock mounted movable in translation and in rotation on the end piece, on a transverse shaft perpendicular to the two parallel walls of the tool, the radial end, relatively to the shaft of this lock having an oblique axis profile relative to said shaft, a stop integral with the tool and having a profile of shape combined with that of the lock and of axis parallel to the axis of the profile of the lock, the lock coming to engage, in the manner of a wedge, between one side of the end piece and the stop and to lock in rotation by its profiled side in the profile of the stop, in the locked position, a shaped piece of a crank journaled on the bolt and the arm of which extends transversely to said shaft, a tension spring acting on the arm of the crank parallel to said shaft and pulling the bolt in the direction of the stop, the ext remitted from the hub of the crank being shaped so as to be able to be driven in rotation by means of a key, the hub of the crank having on its periphery teeth cooperating with a pawl opposing rotation of the crank under the effect of said spring, and means for temporarily holding the bolt raised above the stop and laterally moved away from its locking position.

By means of a simple key it is possible to lock and unlock the device. To lock on drives the means of the crank so as to tension the spring which permanently maintains traction on the bolt, the component of the reaction of the stop in the direction of engagement of the male and female parts of the device ensuring the maintenance of the fastener and catching up on the game.

To unlock, it suffices to slightly turn the means of the crank in the same direction and to spread the pawl with your finger to release the crank and allow the spring to relax. It is then easy to push or pull the bolt laterally, to lift it and to hang it laterally to keep it away from and above the stopper, so as to allow the removal of the tool and the engagement of another tool without the bolt interfering with this engagement.

The design of the locking means makes the best use of the space available between the end piece of the machine arm and the tool and these means are relatively well protected against impact.

The accompanying drawing shows, by way of example, an embodiment of the invention.

Figure 1 is a perspective view of the end piece secured to the machine, without the locking means.

Figure 2 is a perspective view of the female part integral with the tool.

Figure 3 is a perspective view of the assembled parts of the fastener showing the locking means in the locked position.

Figure 4 is a perspective view, from a perspective different from that of Figure 3, showing the locking means in the unlocked position.

Like the fastener described in document EP 0 467 837, the fastener shown here comprises on the one hand a male end piece 1, intended to be fixed to the end of the arm of a construction machine. The means of attachment to this arm have not been shown. They are of the same type as those described in document EP 0 467 837. The fastener is also composed of a female part 2, shown in FIG. 2, secured to the tool, for example a shovel bucket .

The end piece 1 is in the form of an openwork box, the side walls of which are provided externally with two pairs of projections, the projections 3, 4 and 5 of which are visible in the drawing. these projections have oblique ramps 6 and 6 'used for fixing and locking. The projections 3 and 4 also have ramps 7 and 8 opposite to the ramps 6 and 6 'and serving to guide the end piece 1 when it engages in the female piece 2. The floor of the end piece has a cut limited by a side 41 on which the locking thrust is exerted.

The female part 2, in the form of an open box, has two parallel lateral walls 9 and 10. The wall 9 has internally three projections 11, 12, 13. The wall 10 internally has three projections 14, 15, 16 located respectively opposite the projections 11, 12, 13. The projections 11 and 12 have ramps 17 and 18, as do the projections 14 and 15. These ramps are intended to cooperate with the ramps 6 and 6 'of the part. terminal 1 for applying the piece 1 against the bottom of the piece 2. The piece 13 has a ramp 19 parallel to the ramp 18. The piece 16 has a similar ramp 20. The spaces between, on the one hand, the projections 12 and 13 and, on the other hand, the projections 15 and 16 are used to guide the projections 4 and 5 during the engagement of the end piece 1 in the female piece 2. During this engagement, the ramps 8 slide on the ramps 19 and 20. When it is engaged in part 2, part 1 comes to bear on the bottom of part 2. It is held laterally by a boss 21 engaging in a corresponding depression formed in part 1.

We will now describe, by means of FIGS. 3 and 4, the locking means of the parts 1 and 2. On the bottom of the part 2, at the entry thereof, a stop 22 is formed. This stop 22 has a cylindrical surface profile 23 with an oblique axis relative to the walls 9 and 10.

On the end piece 1 is mounted a lock 24 having, seen in plan, a wedge shape and an oblique side 24a of cylindrical profile similar to the profile 23 of the stop and whose axis is parallel to that of the stop. This lock 24 is fixed, by a bent radial arm 25, to a shaft 26 rotatably mounted in two bearings 27 and 28 fixed in the floor of the end piece 1. The shaft 26 is furthermore movable in translation in the bearings 27 and 28. On the latch 24 is journalled a crank 29 about an axis perpendicular to the arm 25. The end of the arm of the crank 29 is provided with a crank pin 30 to which is hooked one of the ends of a spring 31 extending parallel to the shaft 26 and the other end of which is attached to the workpiece 1. The spring 31 works in traction. The hub of the crank 29 is provided with radial teeth 32 cooperating with a pawl 33 journalled on the latch 24 around an axis 34 and held in abutment against the teeth of the crank by a light spring. The end of the hub of the crank 29 is in the form of a standardized hexagon 35. The lock 24 is further provided laterally with a ring 36. The side wall of the end piece 1 opposite this ring 36 is provided with 'a perpendicular arm 37 at the end of which is formed a cylindrical finger 38 whose diameter is less than the inner diameter of the ring 36. The latch 24 is further provided with a protuberance 39 having a flat protruding above the stop 22 in the locked position. The role of this protuberance will appear during the description of the unlocking. The end 26a of the shaft 26 projecting from the bearing 28 in the locked position can be pierced with a diametrical hole 40 intended to receive a safety pin.

The device having been described in the locked position, its use will be described from the locked position shown in position 3.

In this locked position, the end piece 1 is fully engaged in the female part 2 and the latch 24 is fully engaged, in the manner of a wedge, between the front face 41 of the end piece and the stop 22 with its rounded part 24a engaged in the groove 23 of the stop 22. By means of a key, the user has turned the axis of the crank 29 by its hexagon 35 counter-clockwise, which has had the effect to give a certain tension to the spring 31. The spring thus pulls on the crank 29, that is to say on the latch 24 in the direction of the bearing 28. The hub of the crank is retained by the pawl 33. The reaction of the stop 22 on the face 41 maintains a permanent thrust in the direction of engagement of the parts 1 and 2. It will be noted that the forces to which the shaft 26 is subjected and its bearings 27 and 28 are very weak.

To remove the tool, parts 1 and 2 are unlocked. By means of the key, the hub of the crank 29 is slightly turned by its hexagon 35 anticlockwise so as to allow the release of the pawl 33 teeth 32. This release is easily done with the finger, the pawl spring offering little resistance. The spring 31 can thus relax, which makes it possible to easily move the latch 24 to the left so as to disengage it from the groove 23 of the stop. If necessary, one or two hammer blows are given on the protuberance 39 to take off the lock 24 from the stop 22. As soon as this clearance is sufficient, the lock 24 is raised and hung by its ring 36 on the finger 38, as shown in Figure 4. In this position a slight tension on the spring 31 ensures the maintenance in the hooked position. It is then possible to remove the part 1 from the female part 2, the latch 24 passing over the stop 22.

Conversely, the lock 24 being in the hooked position shown in Figure 4, it is possible to engage the end piece 1 in the female part 2 of a tool. Once in the position shown in Figure 4, the latch 24 is released from the finger 38 and pushed or pulled by the spring 31 in the groove 23 of the stop 22. By means of the key, the spring 31 is given the desired tension. We find ourselves in the position shown in Figure 3.

The profile of the stop and the lock could of course be different from the profile shown. The latch and the stop could for example be supported by pependicular faces at the bottom of the part 2 or slightly oblique relative to this bottom. The lock could be kept in the raised position and removed from the stop by any other means.

Claims (6)

1. Device for fast fixing of a tool to the end of the arm of a construction machine, comprising a terminal piece (1) to be fastened to the end of said arm and provided with two pairs of lateral protrusions (4,5) with ramps (6,6') which cling to corresponding ramps (17,18) of two pairs of corresponding protrusions (11,12,14,15) formed on the opposite faces of two parallel walls of the tool, and locking means exerting and maintaining an engaging thrust on said protrusions for applying and maintaining the tool against the terminal piece, characterised in that the locking means comprise a latch (24) mounted mobile in translation and in rotation on the terminal piece, on a transversal shaft (26) perpendicular to said parallel walls, the radial extremity, with respect to the shaft, of said latch having an oblique axis profile relatively to said shaft, an abutment (22) fixed to the tool and presenting a profile (23) with a shape matching the shape of the latch and having an axis parallel to the axis of the profile of the latch, the latch being engaged, as a wedge, between a side (41) of the terminal piece and the abutment (22) and locked in rotation through its profiled side (24a) in the profile of the abutment, in a locking position, a crank-shaped piece (29) pivoted on the latch, the arm of which extends transversally to said shaft, a draw spring (31) acting on the crank handle parallel to said shaft and pulling the latch towards the abutment, the crank hub extremity being formed to be rotationally driven by a key, the crank hub having, on its periphery, teeth co-operating with a ratchet (33) opposed to a rotation of the crank caused by said spring, and means (36,38) for temporarily maintaining the latch raised above the abutment and remote from its locking position.
2. Device as claimed in claim 1, characterised in that the latch (24) and the abutment (22) present a rounded profile (24a,23).
3. Device as claimed in claim 1 or 2, characterised in that the means for maintaining the latch raised and remote from the abutment are constituted by a ring (36) fixed to the latch and a finger (38) fixed to the terminal piece, on which the ring is placed in raised and in remote position.
4. Device as claimed in any of claims 1, 2 or 3, characterised in that the locking means are situated in the space comprised between the terminal piece and the tool, the height of said space being determined by the height of the clinging protrusions.
5. Device as claimed in one of claims 1 to 4, characterised in that the latch (24) is fixed to the shaft (26) and in that said shaft is mounted rotating and sliding in two bearings (27,28).
6. Device as claimed in claim 5, characterised in that the part of shaft which exceeds the bearing (28) on the tension side has at least a diametral hole in which a removable safety pin is engaged.

Images