Quick-release fastener for construction machinery

The present invention relates to a construction machine, for example a mechanical shovel, to which a tool, such as a bucket, is attached in a movable manner, by means of a device forming a quick coupler consisting of a coupler, also known as a quick-release fastener, attached to the machine, particularly to an arm of the machine, and a connection device attached to the tool to engage with the coupler. The present invention also relates to a device forming a quick coupler of this kind and a coupler or quick-release fastener of this kind and a connection device of this kind.

The term ‘bucket’ will be used below. However, the term ‘bucket’ must be understood to also cover any other tool or equipment intended to be mounted on a construction machine by means of the quick-release fastener and connection device.

Traditionally, the connection device that is intended to be attached to the bucket comprises at least one coupling trunnion or hook, in particular, in the case of what are known as reversible devices, two parallel, cylindrical, circular trunnions or axles, the coupling trunnion or hook being arranged such as to each be able to engage with a respective hook or trunnion originating from the coupler to create a coupling between the coupler or quick-release fastener and the connection device to thus achieve coupling of the bucket to the arm of the construction machine.

These couplers of the prior art are dangerous in use. In particular, once the coupling has been carried out, it needs to be locked and before locking it is possible that the coupling may become disconnected and the bucket may then fall onto the construction site where people are present, which may prove extremely dangerous.

The object of the present invention is to overcome the disadvantages of the prior art by proposing a device forming a coupler, in particular a so-called reversible coupler, as well as a coupler or quick-release fastener and/or a connection device to be used in a device forming a coupler of this kind, which are safer to use.

According to a first aspect of the invention, a device forming a coupler comprising a coupler, or quick-release fastener, which is intended to be attached to a construction machine, such as a mechanical shovel, and a connection device, which is intended to be attached to a tool, such as a bucket, comprising at least one coupling trunnion, or hook respectively, which is intended to be coupled to at least one associated coupling hook, or trunnion respectively, of the quick-release fastener, and locking means intended to lock the quick-release fastener to the connection device, is characterised in that it comprises guide means intended to guide the movement, in particular the pivoting movement, of the quick-release fastener in relation to the connection device after coupling in order to lock the device, in particular self-centring means intended to allow relative self-centring of the quick-release fastener and the connection device, the guide means also guiding the trunnion towards the cavity of the hook.

Thanks to the presence of these guide means, this thus ensures that, after the trunnion and the hook have been coupled together and until they are locked, the quick-release fastener and the connection device are well positioned in relation to one another and, in particular, that the quick-release fastener is not obstructed, or even stopped, in its movement abutting against the connection device and can thus reach their correct position in which locking can take place expediently, thus ensuring that the bucket is connected more securely to the machine.

According to a favourable embodiment, the guide means comprise at least one support pin, in particular protruding laterally from at least one lateral flank of the connection device, and at least one associated guide section of the at least one support pin, in particular formed in the quick-release fastener, in particular in a lateral flank of the quick-release fastener, the guide section being open at least towards the bottom and towards the outside of the quick-release fastener, in particular towards the bottom, towards the outside and towards the rear of the quick-release fastener.

According to another favourable aspect of the invention, which is independent from the first aspect described above, but which may be combined favourably with the latter, a device forming a coupler comprising a coupler, or quick-release fastener, which is intended to be attached to a construction machine, such as a mechanical shovel, and a connection device, which is intended to be attached to a tool, such as a bucket, comprising at least one coupling trunnion, or hook respectively, which is intended to be coupled to at least one associated coupling hook, or trunnion respectively, of the quick-release fastener, and locking means intended to lock the quick-release fastener to the connection device, is characterised in that it comprises guide means intended to guide the movement, in particular the pivoting movement, of the quick-release fastener in relation to the connection device after coupling in order to lock the device, in particular self-centring means intended to allow relative self-centring of the quick-release fastener and the connection device, the guide means comprising at least one support pin, in particular protruding laterally from at least one lateral flank of the connection device, and at least one associated guide section of the at least one support pin, in particular formed in the quick-release fastener, in particular in a lateral flank of the quick-release fastener, the guide section being open at least towards the bottom and towards the outside of the quick-release fastener, in particular towards the bottom, towards the outside and towards the rear of the quick-release fastener, the or each guide section comprising a lower region, the lengthwise dimension of which, i.e. in the front-to-back direction of the quick-release fastener, tapers towards the top, followed by an upper region, the lengthwise dimension of which is substantially constant up to its top, the two regions being separated by an elbow formed in the front wall of the section.

Preferably, seen in longitudinal section, the or each section comprises a longitudinal wall forming a substantially horizontal top, followed by a substantially vertical upper front wall, which is itself followed by a lower front wall that extends up to the lower opening of the section such as to form the elbow with the upper front wall.

According to a preferred embodiment, the quick-release fastener comprises at least one coupling hook and the connection device at least one coupling trunnion, and the or each hook comprises a part forming a rod and a part forming a coupling head which extends upwards from the end of the part forming a rod to thus define a respective cavity in which a trunnion of the connection device is intended to be inserted via a respective upper opening.

Preferably, the cavity comprises a respective recessed area, in particular created in the front edge of the or each lateral flank of the quick-release fastener such that, when the trunnion is inserted in the receiving cavity or cavities through the upper opening or openings, the trunnion may be inserted in the or each recessed area, preferably over at least half of its transverse cross-section, i.e. over a sector with an angle of at least 180°.

Preferably, when the or each hook is beneath the front trunnion, the or each support pin abuts against the lower front wall.

Preferably, as the driver of the bucket causes the quick-release fastener to turn in the correct direction in relation to the connection device, the pin moves along the lower front wall until the trunnion reaches its position in the or each recessed area of the or each cavity of the or each hook.

Preferably, when the trunnion reaches the recessed area, the pin reaches the elbow formed between the upper and lower front walls of the guide section.

The present invention also relates to a construction machine comprising a lifting element, in particular a lifting arm, and a tool, in particular a bucket, and a device forming a quick coupler according to the invention, the coupler or quick-release fastener being attached to the machine, and the connection device being attached to the tool.

The present invention also relates to a connection device of a device forming a coupler, comprising a coupler, or quick-release fastener, which is intended to be attached to a construction machine, such as a mechanical shovel, and the connection device comprising attachment means intended to allow it to be attached to a tool, such as a bucket, and at least one coupling trunnion, or hook respectively, intended to be coupled to at least one associated hook, or trunnion respectively, of the quick-release fastener, characterised in that it comprises guide means intended to guide the relative pivoting movement of the quick-release fastener, in particular self-centring means intended to allow relative self-centring of the quick-release fastener and the connection device, for example at least one pin, in particular protruding laterally from the inner surface of at least one lateral flank of the connection device, in particular two pins, left and right respectively, protruding laterally from the respective inner surfaces of two left and right lateral flanks of the connection device.

The present invention also relates to a coupler or quick-release fastener of a device forming a coupler, comprising the coupler, or quick-release fastener, which is intended to be attached to a construction machine, such as a mechanical shovel, and a connection device intended to be attached to a tool, such as a bucket, the coupler or quick-release fastener comprising at least one coupling hook, or trunnion respectively, which is intended to be coupled to at least one associated trunnion, or hook respectively, of the connection device, characterised in that it comprises guide means intended to guide the relative pivoting movement of the connection device, in particular self-centring means intended to allow relative self-centring of the quick-release fastener and the connection device, for example at least one guide section, in particular formed in a lateral flank of the quick-release fastener, the guide section being open at least towards the bottom and towards the outside of the quick-release fastener, in particular two guide sections formed in two left and right lateral flanks of the quick-release fastener.

The figures show a quick-release fastenerwhich engages with a connection device, which is itself attached to a bucket.

The connection devicecomprises a base plate from the upper face of which two lateral flanksextend in a perpendicular manner. Two parallel, cylindrical-circular-shaped trunnions, topand bottomrespectively (when the bucket is placed on the ground), are attached to the two flanks such as to extend from one to the other at a distance from the base plate to allow two front hooksoriginating from the quick-release fastener to pass between them and the base plate.

The quick-release coupler is shown in detail, in an exploded view, in. The only items missing from this figure are the two lateral wingssupporting the axles enabling the quick-release fastenerto be attached to the arm of the lever of a construction machine such as the arm of a mechanical shovel.

The quick-release fastenercomprises a bottom body comprising an upper base plateand two lower lateral flanks(only one is visible on) originating from the upper plate, each flankterminating, on a side subsequently referred to as the front side, in a respective front hook.

A componentforming a lever is mounted such that it pivots with respect to an axleparallel to the axle of the trunnions when the quick-release fastener and the connection device are locked together. The axleis connected to the quick-release fastener but is able to undergo a limited movement through the oblong openingsformed by the lateral flanks.

Two rollerswhich are able to roll from one side to the other of the oblong openingsare attached by bolts (shown in the figure but not referred to by reference numerals) on each side of the axle. However, this attachment does not prevent relative rotation of the rollers around the axle, thus allowing the axle, and thus also the lever, to be driven in translation, even if said lever does not pivot.

The levercomprises two upper left and right branchesand two lower left and right branches, which extend backwards from the axle. The upper branches extend further backwards than the lower branches. The left upper and lower branches define a left-hand, C-shaped space, the opening of which is turned towards the back and in the same manner, the right upper and lower branches define a right-hand C-shaped space, the opening of which is turned towards the back.

Two right and left front branchesextend forwards from the axle. They each consist of a proximal portionfollowed by a distal portion, which extends in an inclined manner in relation to the proximal portion, in particular substantially at 90°. The two distal portionspass through two through openings, left and right respectively, formed through the base plateof the quick-release fastener to emerge from the upper surface of the base plate and are each fixed to a front end of a spring, left and right respectively, while the other respective ends of each springare attached to two left and right studsin the form of hooks originating from the upper face of the base plate, substantially in the region of the rear edge of the base plate. The springsare tension springs that tend to draw the front ends of the distal portions backwards. Two left and right coversare attached by bolts (shown but not referred to in the figure) against the lateral flanksto conceal and/or protect the openingsfrom the exterior, in particular to prevent earth getting lodged in the oblong openingsand impeding movement of the rollers.

A rear platewhich substantially takes the shape of a rectangular parallelepiped extends transversely between the two lateral flanks, substantially in the region of the rear edge of the base plate. The rear plateis attached to the flanks by bolts and holes, shown inbut without reference numerals. A rear notchis formed centrally in the upper edge of the rear plate, on the rear side of the plate.

In longitudinal section, the rear face of the rear plateis substantially rectilinear and vertical. The front face of the rear platein turn comprises a first substantially vertical lower portion, followed by an upper portion inclined upwards towards the rear.

A component, referred to as a lug, is mounted on the lever, between the left and right upper branches, being able to pivot with respect to the lever, with respect to an axle, parallel to the axleand which extends into the space between the two upper branchesof the lever. The axleof the lugis attached to the leverby means of a support componentin the form of a bridge attached to the upper face of the upper branchesby corresponding bolts and holes shown onbut not referred to by reference numerals. A torsion springis attached such that it acts on the lug. The lugcomprises, on either side of the axle, a rear partand a front part, the front parthaving smaller dimensions than the rear part, and thus a lower weight, such that the lug tends, under the effect of its own weight, to swing in a direction such as to cause its rear part to fall downwards (anticlockwise direction in the figures). The torsion springis mounted such as to act on the lugin a manner that also loads the rear part downwards. The rear partcomprises an upper protrusionand terminates in a rear tooth, which projects towards the bottom of the remainder of the rear part and which has dimensions enabling it to penetrate the rear notchof the plate. A groovewhich is intended to receive the upper protrusionis formed in the lower face of the base platewhen the upper branchesof the leverare positioned such that they are abutted against the lower face of the base plate.

On the front side, the quick-release fastenerdefines two respective receiving cavitiesfor one or other of the two trunnionsandof the connection device. Two receiving cutoutsfor the other of the two axlesandof the connection device are formed in the lateral flankson the rear side of the plate.

Each hookcomprises a partforming a rod that extends at the front end of one of the respective flanks, parallel to the plane of the plate, and terminates in a partforming a coupling head, which extends upwards from the end of the partforming a rod. Each hookthus defines, with the front edges of the lateral flanks, two cavitiesin which one or other, depending on the direction in which they are inserted in relation to the bucket, of the two axlesandoriginating from the connection deviceattached to the bucketare intended to be inserted through respective upper openings. The cavitycomprises a respective recessed areacreated in the front edge of each lateral flankand with a shape that complements at least half of the circular transverse cross-section of the axlesandsuch that, when the axleororiginating from the bucket is inserted in the receiving cavitiesthrough the openings, the axle can be inserted in the recessover at least half of its transverse cross-section, i.e. over a sector with an angle of at least 180°.

In relation to the lower, or bottom, surfaceof each cavity, the uppermost endof the partforming the head extends in the vertical direction at least in the region of the centre of the cross-section of the axleorwhen this is located in the cavity, in particular above the centre, and in particular substantially in the region of the diameter, or even above the diameter. Similarly, the uppermost endof the surface of the part forming the head of the side of the cavityextends above the centre of the axleor, in particular at a height between the radius and the diameter, or could even extend substantially to a height equal to the diameter of the axle.

The respective dimensions of the axles of the trunnions of the connection device attached to the bucket and the cavitiesformed by the hooksare selected such that once the headpart has been inserted beneath the axleorof the bucket, as shown onfor example, and the operator of the lifting machine causes the coupler to turn in the wrong direction, i.e. in the clockwise direction in, the shoulder formed between the edgeof the openingand the upper edgeof the plateof the quick-release fastenerwill abut against the edges of the flanksof the connection device originating from the bucketsuch that even though the operator has started to raise the bucket away from the ground, the quick-release fastener and the connection device can no longer pivot in relation to one another, the top part of the hook thus still remaining beneath the axle and preventing this axle, and thus also the bucket, from falling back to the ground, the stop in the region of the shoulder preventing any sudden withdrawal of the axle from the cavities. This stop comes into play beyond a rotation in the wrong direction of approximately 15°.

If the bucket operator causes the quick-release fastener to turn in the right direction (in the anticlockwise direction in) to lock the coupler to the connection device of the bucket, the cutoutscover the other axleof the bucket from above.

As the operator causes the quick-release fastener to pivot to insert the second axlein the cutouts, the second axleof the bucket comes to bear against the upper branchesof the lever, causing said lever to pivot and retreat (towards the front). At the limit of travel, the upper faces of the two upper branchesare parallel with the lower face of the base plateand, at the same time, the lug, which is mounted such that it pivots in relation to the leveris pushed by the springstowards the rear such that its toothpasses over the upper edge of the rear plateand penetrates the notch.

This backwards movement, under the effect of the springs, also drives the rear lower branches of the lever, which thus pass beneath the trunnion, trapping it in the cavity.

Thus, as shown on, the quick-release fastener is locked to the bucket. This is a well secured locking mechanism, and, in particular, even if one or more springswere to break or become detached, the quick-release fastener of the bucket would not become unlocked, thus being held in a secure manner.

The toothhas a rear surface that is inclined upwards and backwards such that when the springspush the leverbackwards again once this is in position with the rear upper branches in the horizontal direction, the pushing force, in conjunction with the inclined shape of the rear face of the tooth, causes the lug to pivot away from the torsion spring and allows the toothto pass into the notch.

shows a wrenchenabling the fastener to be unlocked once said fastener has been locked, i.e. once the toothhas swung into the notchof the plate.

The wrench comprises an extended handle(only part of said handle is shown in the figure) terminating in a head part comprising two upperand lowerlateral arms and a central projection. A studextends transversely from the end of the upper arm, in a direction perpendicular to the handle such that it can penetrate an eyelet formed in a studoriginating from the upper face of the plateof the fastener. A noseoriginates from the lower lateral arm, said nose extending towards the upper arm.

In order to unlock the fastener, the user inserts the studin the eyelet and causes the end of the noseto move against the rear face of the protrusionof the tooth, the dimensions of the nosebeing such that it can penetrate the groovein which the protrusionis received, then exerts a rotation movement such that the proximal end of the handle (the opposite end to the head) is moved downwards, which has the effect of causing the lug to pivot away from the torsion springand causing the toothto come out of the notch, thus unlocking the quick-release fastener.

As shown in, when the hookscome below the front trunnionby their ends, each support pincomes in abutment against the lower front wall(). As the controller of the bucket makes the quick release fastener to rotate in the correct direction in relation to the connection device, the pinmoves along the wallup to the point when the trunnionreaches its position in the recessed areaof the cavitiesof the hooks, as shown in. The pinis then positioned at the entrance of the upper regionand passes therefore over the elbow, in contact with lower front wall. As the rotation keeps going on, pinreaches the top wall. In this final position, the quick release fastener and the connection device can then be mutually locked.

The quick release fastener ofis identical to the one of, except that two left and right guiding cut-outs are formed in the external surfaces of the left and right lateral flanks, the right guiding cut-outbeing visible in, while the left guiding cut-outis visible in.

in, the right lateral flankcomprises a right guiding cut-outformed in the external wall of the lateral flank. The left lateral flank, visible in, comprises a same guiding cut-out formed in its external wall. Guiding cut-outis open toward the bottom, towards the outside and towards the rear and comprises a lower region, the longitudinal dimension of length of which, that is in the front-rear direction of the quick release fastener, narrows toward the top, followed by an upper region, the length dimension of which is substantially constant up to the top.

Thus, as seen in longitudinal cross section, cut outcomprises a longitudinal top forming wall, substantially horizontal, followed by a upper front wall, substantially vertical, followed by a lower front wallwhich extends up to the lower opening of the cut out, being inclined in respect of the upper front wall, notably of an angle of around 45°, so as to form an elbow.

A right support pinprojects toward the inside of the right lateral flankof the connection deviceand is intended to cooperate with the right cut out. A left support pin, identical to the right support pin, projects from the left lateral flankand is intended to cooperate with the left cut out.

As shown in, when the hookscome below the front trunnionby their ends, each support pincomes in abutment against the lower front wall(). As the controller of the bucket makes the quick release fastener to rotate in the correct direction in relation to the connection device, the pinmoves along the wallup to the point when the trunnionreaches its position in the recessed areaof the cavitiesof the hooks, as shown in. The pinis then positioned at the entrance of the upper regionand passes therefore over the elbow, in contact with lower front wall. As the rotation keeps going on, pinreaches the top wall. In this final position, the quick release fastener and the connection device can then be mutually locked.

In, only pinis shown, the right lateral flank having been omitted for sake of clarity concerning the interaction between the pin and the quick release fastener.

In this description, the vertical direction is defined as being perpendicular to the plane of the upper face of the base plateof the quick-release fastener, the top side being the side towards which the opening of the cavityis turned. The terms proximal and distal are defined in relation to the centre of the quick-release fastener.

In particular, the terms top and bottom and lower and upper are defined in relation to this vertical direction, the connection device, which is attached to the bucket, being located beneath the quick-release fastener in the locked position.