High-security quick-release fastener

Abstract

A device forming a coupler including a coupler, or quick-release fastener, and a connection device; the connection device including at least one, preferably two, trunnions, front and back respectively; the coupler including a base body from which, on a front side, at least one hook originates having a region forming a rod and a region forming a hook head extending upwards from the region forming a rod to form, with the base body, at least one receiving cavity for the trunnion or trunnions, having an opening at the top extending between the base body and the region forming the respective head of the respective hook. When the trunnion or trunnions in the receiving cavity comes into contact with the region forming a rod, the region forming a head extends upwards beyond the centre of the circular section of the trunnion.

Claims

1. A device forming a coupler comprising a coupler (1), or quick-release fastener, which is intended to be attached to a construction machine, such as a mechanical shovel, and a connection device (2), which is intended to be attached to a tool such as a bucket; the connection device comprising at least one trunnion (5; 6; 5, 6), preferably two trunnions (5, 6); the coupler comprising a base body from which, on a front side, at least one hook originates, the or each hook (7) having a part forming a rod and a part (72) forming a hook head, which extends upwards from the part forming a rod to define at least one receiving cavity (200) for the trunnion or one of the trunnions, having an opening (201) at the top which extends between the base body and the part forming the respective head of the respective hook: characterised in that, when the trunnion or one of the trunnions in the receiving cavity comes into contact with the part forming a rod, the part forming a head extends upwards beyond the centre of the circular section of the trunnion, the or each receiving cavity comprising, on the rear side, a recessed area created in the base body in which the trunnion can penetrate at least in part, the or each hook (7) not being mobile in relation to the base body.

2. The device according to claim 1, characterised in that the part forming the head extends upwards beyond the trunnion.

3. The device according to claim 1, characterised in that the recessed area has a shape that, in longitudinal section, complements substantially at least half of the circular section of the trunnion.

4. The device according to claim 1, characterised in that the connection device (2) comprises a lower base plate and on the upper side two lateral flanks, two trunnions spaced apart from one another being attached to the two flanks so as to extend between them, at a distance from the base plate, to allow the or each front hook of the quick-release fastener to pass between them and the base plate.

5. The device according to claim 1, characterised in that the coupler (1) or quick-release fastener, comprises an upper base plate (101) from which two lateral flanks (102) protrude downwards, each flank (102) terminating on the front side in a respective hook (7).

6. The device according to claim 1, characterised in that, in longitudinal section, the highest point of the part forming the hook head is beyond the trunnion when said trunnion is located in the cavity, in contact with the part forming a rod.

7. The device according to claim 1, characterised in that, in longitudinal section, the highest point of the inner wall of the part of the cavity formed by the part forming the hook head is beyond the centre of the trunnion section, and in particular substantially at a level between the radius and diameter of the trunnion section.

8. The device according to claim 1, characterised in that the connection device comprises two trunnions and, in the base body of the coupler, at least one second rear cavity for receiving the trunnion is defined, intended to receive the other trunnion once the first trunnion is attached to the hook or to each hook, said second rear cavity being open at the bottom, i.e. in the opposite direction to the direction towards which the opening of the first front receiving cavity faces.

9. A quick-release fastener forming part of a device according to claim 1.

Description

[0022] By way of example only, a preferred embodiment of the invention will now be described with reference to the drawings in which:

[0023] FIG. 1 is a side view showing, on the one hand, the coupler or quick-release fastener and, on the other hand, the bucket to which a connection device has been attached, said device comprising two trunnions, the figure showing the coupler at a distance from the bucket, i.e. in a position in which attachment or coupling has not yet started;

[0024] FIG. 2 is a larger-scale view of part of FIG. 1 showing the hook of the coupler which has been inserted beneath one of the two trunnions of the connection device;

[0025] FIG. 3 is a view that is substantially identical to the view in FIG. 2, in which the hook is attached to the trunnion and the bucket has been raised above the ground;

[0026] FIG. 4 is a view showing the relative position of the coupler and the bucket when the operator has activated the coupler to swing in the wrong direction, i.e. in the figure, pivoting the top part of the coupler with respect to the bottom part in the clockwise direction;

[0027] FIGS. 5, 6 and 7 show the same coupler and bucket from FIGS. 1 to 4, but in a configuration in which the first coupling stage takes place by means of the other of the two trunnions, the coupler being oriented, with respect to the bucket, inverted through 180 compared to FIGS. 1 to 4;

[0028] FIG. 8 shows an identical situation to that shown in FIG. 4 but with the reverse orientation of the quick-release fastener shown in FIGS. 5 to 7;

[0029] FIG. 9 is an exploded perspective view of the various elements forming the quick-release fastener;

[0030] FIG. 10 is a longitudinal sectional view of the quick-release fastener from FIG. 9, showing how the fastener is locked once coupling of the hook to one of the connection device trunnions has been achieved;

[0031] FIG. 11 is a similar view to FIG. 10 in which the second trunnion has penetrated the inside of the quick-release fastener;

[0032] FIG. 12 is a similar view to FIGS. 10 and 11, showing the locked position of the quick-release fastener;

[0033] FIGS. 13, 14, 15, 16 show the relative positions of the various elements involved in locking the fastener at various moments of the locking action;

[0034] FIG. 17 shows the unlocking wrench and its position in relation to the fastener in order to unlock said fastener;

[0035] FIG. 18 shows the relative position of the lever axle in relation to the oblong opening in which it is able to move in translation when the fastener is in the position shown in FIG. 11; and

[0036] FIG. 19 shows the relative position of the lever axle in relation to the oblong opening in which it is able to move in translation when the fastener is in the position shown in FIG. 12; and

[0037] The figures show a quick-release fastener 1 which engages with a connection device 2, which is itself attached to a bucket 3.

[0038] The connection device 2 comprises a base plate from the upper face of which two lateral flanks 4 extend in a perpendicular manner. Two parallel, cylindrical-circular-shaped trunnions, top 5 and bottom 6 respectively (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 hooks 7 originating from the quick-release fastener to pass between them and the base plate.

[0039] The quick-release coupler is shown in detail, in an exploded view, in FIG. 9. The only items missing from this figure are the two lateral wings 8 supporting the axles enabling the quick-release fastener 1 to be attached to the arm of the lever of a construction machine such as the arm of a mechanical shovel.

[0040] The quick-release fastener 1 comprises a bottom body comprising an upper base plate 101 and two lower lateral flanks 102 (only one is visible on FIG. 9) originating from the upper plate 101, each flank 102 terminating, on a side subsequently referred to as the front side, in a respective front hook 7.

[0041] A component 103 forming a lever is mounted such that it pivots with respect to an axle 104 parallel to the axle of the trunnions when the quick-release fastener and the connection device are locked together. The axle 104 is connected to the quick-release fastener but is able to undergo a limited movement through the oblong openings 109 formed by the lateral flanks 102.

[0042] Two rollers 120 which are able to roll from one side to the other of the oblong openings 109 are attached by bolts (shown in the figure but not referred to by reference numerals) on each side of the axle 104. However, this attachment does not prevent relative rotation of the rollers around the axle 104, thus allowing the axle 104, and thus also the lever 103, to be driven in translation, even if said lever does not pivot.

[0043] The lever 103 comprises two upper left and right branches 105 and two lower left and right branches 106, which extend backwards from the axle 104. 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.

[0044] Two right and left front branches 107 extend forwards from the axle 104. They each consist of a proximal portion 108 followed by a distal portion 111, which extends in an inclined manner in relation to the proximal portion 108, in particular substantially at 90. The two distal portions 111 pass through two through openings 112, left and right respectively, formed through the base plate 101 of 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 400, left and right respectively, while the other respective ends of each spring 400 are attached to two left and right studs 113 in the form of hooks originating from the upper face of the base plate 101, substantially in the region of the rear edge of the base plate 101. The springs 400 are tension springs that tend to draw the front ends of the distal portions backwards. Two left and right covers 114 are attached by bolts (shown but not referred to in the figure) against the lateral flanks 102 to conceal and/or protect the openings 109 from the exterior, in particular to prevent earth getting lodged in the oblong openings 109 and impeding movement of the rollers 120.

[0045] A rear plate 500 which substantially takes the shape of a rectangular parallelepiped extends transversely between the two lateral flanks 102, substantially in the region of the rear edge of the base plate 101. The rear plate 500 is attached to the flanks by bolts and holes, shown in FIG. 9 but without reference numerals. A rear notch 501 is formed centrally in the upper edge of the rear plate 500, on the rear side of the plate.

[0046] In longitudinal section, the rear face of the rear plate 500 is substantially rectilinear and vertical. The front face of the rear plate 500 in turn comprises a first substantially vertical lower portion, followed by an upper portion inclined upwards towards the rear.

[0047] A component 502, referred to as a lug, is mounted on the lever 103, between the left and right upper branches 105, being able to pivot with respect to the lever 103, with respect to an axle 503, parallel to the axle 104 and which extends into the space between the two upper branches 105 of the lever 103. The axle 503 of the lug 502 is attached to the lever 103 by means of a support component 504 in the form of a bridge attached to the upper face of the upper branches 105 by corresponding bolts and holes shown on FIG. 9 but not referred to by reference numerals. A torsion spring 505 is attached such that it acts on the lug 502. The lug 502 comprises, on either side of the axle 503, a rear part 506 and a front part 507, the front part 507 having smaller dimensions than the rear part 506, 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 spring 505 is mounted such as to act on the lug 502 in a manner that also loads the rear part downwards. The rear part 506 comprises an upper protrusion 508 and terminates in a rear tooth 509, which projects towards the bottom of the remainder of the rear part and which has dimensions enabling it to penetrate the rear notch 501 of the plate 500. A groove 510 which is intended to receive the upper protrusion 508 is formed in the lower face of the base plate 101 when the upper branches 105 of the lever 103 are positioned such that they are abutted against the lower face of the base plate 101.

[0048] On the front side, the quick-release fastener 1 defines two respective receiving cavities 200 for one or other of the two trunnions 5 and 6 of the connection device 2. Two receiving cutouts 300 for the other of the two axles 5 and 6 of the connection device are formed in the lateral flanks 102 on the rear side of the plate 101.

[0049] Each hook 7 comprises a part 71 forming a rod that extends at the front end of one of the respective flanks 102, parallel to the plane of the plate 101, and terminates in a part 72 forming a coupling head, which extends upwards from the end of the part 71 forming a rod. Each hook 7 thus defines, with the front edges of the lateral flanks 102, two cavities 200 in which one or other, depending on the direction in which they are inserted in relation to the bucket, of the two axles 5 and 6 originating from the connection device 2 attached to the bucket 3 are intended to be inserted through respective upper openings 201. The cavity 200 comprises a respective recessed area 202 created in the front edge of each lateral flank 102 and with a shape that complements at least half of the circular transverse cross-section of the axles 5 and 6 such that, when the axle 5 or 6 originating from the bucket is inserted in the receiving cavities 200 through the openings 201, the axle can be inserted in the recess 202 over at least half of its transverse cross-section, i.e. over a sector with an angle of at least 180.

[0050] In relation to the lower, or bottom, surface 210 of each cavity 200, the uppermost end 203 of the part 72 forming the head extends in the vertical direction at least in the region of the centre of the cross-section of the axle 5 or 6 when this is located in the cavity 200, in particular above the centre, and in particular substantially in the region of the diameter, or even above the diameter. Similarly, the uppermost end 204 of the surface of the part forming the head of the side of the cavity 200 extends above the centre of the axle 5 or 6, 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.

[0051] The respective dimensions of the axles of the trunnions of the connection device attached to the bucket and the cavities 200 formed by the hooks 7 are selected such that once the head 72 part has been inserted beneath the axle 5 or 6 of the bucket, as shown on FIG. 4 for example, and the operator of the lifting machine causes the coupler to turn in the wrong direction, i.e. in the clockwise direction in FIGS. 1 to 4, the shoulder formed between the edge 205 of the opening 201 and the upper edge 206 of the plate 101 of the quick-release fastener 1 will abut against the edges of the flanks 4 of the connection device originating from the bucket 3 such 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 200. This stop comes into play beyond a rotation in the wrong direction of approximately 15.

[0052] If the bucket operator causes the quick-release fastener to turn in the right direction (in the anticlockwise direction in FIGS. 1 to 4) to lock the coupler to the connection device of the bucket, the cutouts 300 cover the other axle 5 of the bucket from above.

[0053] As the operator causes the quick-release fastener to pivot to insert the second axle 5 in the cutouts 300, the second axle 5 of the bucket comes to bear against the upper branches 105 of the lever 103, causing said lever to pivot and retreat (towards the front). At the limit of travel, the upper faces of the two upper branches 105 are parallel with the lower face of the base plate 101 and, at the same time, the lug 502, which is mounted such that it pivots in relation to the lever 103 is pushed by the springs 400 towards the rear such that its tooth 509 passes over the upper edge of the rear plate 500 and penetrates the notch 501.

[0054] This backwards movement, under the effect of the springs 400, also drives the rear lower branches of the lever, which thus pass beneath the trunnion, trapping it in the cavity 300.

[0055] Thus, as shown on FIGS. 12 and 16, the quick-release fastener is locked to the bucket. This is a well secured locking mechanism, and, in particular, even if one or more springs 400 were to break or become detached, the quick-release fastener of the bucket would not become unlocked, thus being held in a secure manner.

[0056] The tooth 509 has a rear surface that is inclined upwards and backwards such that when the springs 400 push the lever 103 backwards 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 tooth 509 to pass into the notch 501.

[0057] FIG. 17 shows a wrench 600 enabling the fastener to be unlocked once said fastener has been locked, i.e. once the tooth 509 has swung into the notch 501 of the plate 500.

[0058] The wrench comprises an extended handle 601 (only part of said handle is shown in the figure) terminating in a head part comprising two upper 603 and lower 604 lateral arms and a central projection 605. A stud 606 extends transversely from the end of the upper arm 603, in a direction perpendicular to the handle such that it can penetrate an eyelet formed in a stud 700 originating from the upper face of the plate 101 of the fastener. A nose 609 originates from the lower lateral arm, said nose extending towards the upper arm.

[0059] In order to unlock the fastener, the user inserts the stud 606 in the eyelet and causes the end of the nose 609 to move against the rear face of the protrusion 508 of the tooth 502, the dimensions of the nose 609 being such that it can penetrate the groove 511 in which the protrusion 508 is 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 spring 605 and causing the tooth 509 to come out of the notch 501, thus unlocking the quick-release fastener.

[0060] In this description, the vertical direction is defined as being perpendicular to the plane of the upper face of the base plate 101 of the quick-release fastener, the top side being the side towards which the opening of the cavity 200 is turned. The terms proximal and distal are defined in relation to the centre of the quick-release fastener.

[0061] 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.