Device for coupling a tool to pivoting arms of an earthmoving machine or the like.

Abstract: Device for connecting an implement to pivoting arms of an earthmoving machine or the like, whereby the device comprises a connecting piece (1), which is provided with coupling ears for pivotally coupling the connect­ ing piece to the arms of the excavator. The connecting piece is also provided with a lock (24) displaceable in its longitudinal direction by means of an adjusting means provided on the connecting piece, and with a coupling bar extending transversely to the longitudinal direction of the lock. The coupling bar fits a cavity bounded by a part of the tool, which is further provided with a recess for accommodating the conical end of the lock remote from the coupling bar. When the end of the lock is pressed into the recess upon coupling the connecting piece to the tool the coupling bar is pressed into the cavity, the part of the connecting piece located near the end of the lock is pushed in the direction of the tool, and wedge faces provided on the connecting piece and the tool are pressed together.

Description: The invention relates to a device for coupling a tool to pivoting arms of an earthmoving machine or the like, whereby the device comprises a connecting piece, which is provided with coupling ears for pivotally coupling the connecting piece to the arms of the excavator, whilst the connecting piece is provided with at least one lock displace­ able in its longitudinal direction by means of an adjusting means provided on the connecting piece, and with a coupling bar extending transversely to the longitudinal direction of the lock, said bar fitting in a cavity bounded by a part of the tool, which is further provided with a recess for accommodating the conical end of the lock remote from the coupling bar, such that when the end of the lock is pressed into the recess upon coupling the connecting piece to the tool the coupling bar is pressed into the cavity and the part of the connecting piece located near the end of the lock is pushed in the direction of the tool. Such a device is disclosed in the British patent specification 1,089,885. In this known device the connecting piece bears with some flat parts, extending parallel to the direction of displacement of the lock, against corresponding flat parts of the tool, whilst in the attached position the coupling bar bears against the bottom of the cavity accommodating the coupling bar and being bounded by a U-profile. In practice it has become apparent, however, that in many cases an insufficient clamping is obtained, and in particular play may occur in a direction perpendicular to the direction of displacement of the locking pin. According to the invention the connecting piece and the tool are provided with wedge faces, which bear against each other in the position where the connecting piece is attached to the tool and which are orientated such that when the lock is pressed down the wedge faces are pressed together and as a result of that the connecting piece is pushed in the direction of the cavity accommodating the coupling bar. When the end of the lock is pressed into the recess not only a force extending substantially perpendicularly to the direction of dis­ placement of the lock will be exerted on the connecting piece, but also a force extending substantially perpendicularly to the longitudinal direction of the lock, as a result of which a particularly tight clamping of the connecting piece to the tool can be achieved by using this construction. According to a further aspect of the invention the cavity, which accommodates the coupling bar having a round section, has an unround section along at least part of its circumference, such that when the coupling bar is located in the cavity the coupling bar butts against two longitudinal boundary lines in the cavity, the size of whose cross-­ section gradually decreases from said longitudinal boundary lines in a direction remote from the connecting piece. On account of said configuration of the cavity and in co-­ operation with the force exerted on the connecting piece and extending at least substantially in the longitudinal direction of the lock, a particularly good clamping of the drawbar in the cavity will be ef­ fected. Fig 1 is a view of a connecting piece of the device according to the invention. Fig 2 is a side view of fig 1, seen according to the arrow II in fig 1. Fig 3 is a section of fig 1, seen according to the line III-III in fig 1, whereby, however, one lock is only partly illustrated and further parts have been left out for convenience of comparison. Fig 4 is a section of fig 1, seen according to the line IV-IV in fig 1, whereby, however, parts have been left out for convenience of comparison. Fig 5 is a diagrammatic side view of a tool in the shape of an excavator bucket. Fig 6 is a view of the tool illustrated in fig 5, seen according to the arrow VI in fig 5. Fig 7 diagrammatically illustrates the connection between the connecting piece and the parts attached to the tool, whereby the tool has been left out. Fig 8 illustrates on a larger scale the position of the coupling bar of the connecting piece in a cavity accommodating said bar. Fig 9 illustrates on a larger scale the end of the lock with the means accommodating said end and being connected to the tool. The connecting piece 1 illustrated in the figs 1 - 4 comprises an upper coupling bar 2, having a round section, and a lower bar 3, extending parallel to the bar 2, said bar 3 being a little shorter than the bar 2. Near their centres the two bars 2 and 3 are mutually connected by means of a pair of plate-shaped parts 4 and 5 extending perpendicularly to the bars 2 and 3. On both sides of said pair of plate-shaped parts 4 and 5 the bars 2 and 3 are further mutually connected by strip-shaped parts 6, 7, and 8, 9 respectively extending parallel to said plate-shaped parts 4 and 5. The ends of the bar 3 are further connected to the bar 2 by means of plate-shaped parts 10 and 11 extending parallel to the plate-­ shaped parts 4 and 5. To the ends of the bar 2 there are attached plate-­ shaped parts 12 and 13 extending parallel to the plate-shaped parts 10 and 11, whereby the plate-shaped parts 10 - 13 all have the same shape. The bottom ends of the plate-shaped parts 10, 12, and 11, 13 respectively are mutually connected by connecting blocks 14, 15 respect­ ively. In the plate-shaped parts 10 - 13 there are provided holes 16, being in line, for passing through pins by means of which the free ends of arms of an earthmoving machine, not shown, such as e.g. a shovel loader or the like, may be coupled such, that one end of an arm is located between the plates 10 and 12 and is coupled to said plates by means of a pivot pin, and the end of an other arm is located between the plates 11 and 13 and is coupled to said plates 11 and 13 by means of a pivot pin. Holes 17 are provided in the two plates 4 and 5 at some distance above the holes 16, seen in side view (fig 2), through which holes 17 a pin may be passed in order to pivotally couple the end of a further arm of said earthmoving machine located between the plates 4 and 5 to the connecting piece 1. Between the plates 4 and 5 there is furthermore arranged a hydraulic setting cylinder 18, whose casing at its bottom end is pivotally coupled to the connecting piece by means of a pivot pin 18′. The free end of the piston rod 19 of the setting cylinder 18 is pivotally coupled to a yoke 20 by means of a pin 19′ extending parallel to the pin 18′. The yoke 20 extends through slotted holes 21 and 22 provided in the plate shaped parts 4 and 5 and in the strip-­ shaped parts 6 and 9, and the ends of the yoke 20 are coupled to the upper ends of locks 24 by means of pins 23 extending parallel to the pin 19′, said locks 24 being arranged displaceably in their longitudinal direction between guide plates 25 and 26, which are provided between the plate-shaped parts 6, 7, and 8, 9 respectively. As is furthermore illustrated in figs 5 and 6 a tool, e.g. an excavator bucket 27, which is to be coupled to an earthmoving machine or the like by means of the connecting piece 1 illustrated in the figs 1 - 4, is provided with a pair of coupling means 28 fixed to the tool 27 and being arranged at a distance from each other. Each coupling means thereby comprises an elongated strip-shaped part 28′, to whose bottom side there is attached a block 29, which has a recess 30 open at its upper side and at its lower side, the section of said recess gradually becoming smaller in downward direction, as appears from fig 5, and being shaped to correspond with the conical end of the locks 24. At its upper side each coupling means is provided with a hooked part 31 defining a cavity 32 for accommodating the coupling bar 2. As appears in particular from fig 8 the cavity 32 is thereby partly bounded by a boundary face 33 in the form of a circular arc, and by a flat face 34, the purpose of which will be further explained hereinafter. When using the construction according to the invention the connecting piece 1 will be coupled, in the manner described above, to the arms of an earthmoving device, such as e.g. an shovel loader, bulldozer or the like. Of course it will also be possible to couple such a connecting piece 1 to the end of the jib of an excavator. For coupling the connecting piece to a machine provided with coupling means 28 the connecting piece will be manipulated such that the parts of the coupling bar 2 located between the plates 6, 7, and 8, 9 respectively will lie in the cavities 32 bounded by the hooked parts 31, whilst the bar 3 is thereby located at some distance from the blocks 29. Then, by suitably manipulating the connecting piece by means of the arms of the earthmoving device or the like, the connecting piece can be pivoted about the central axis of the coupling bar 2 into a position, in which the conical bottom ends of the locks 24 are located above the recessed in the blocks 29. Subsequently the locks can be pressed downwards by means of the setting cylinder 18 in order to press the conical ends of the locks into the correspondingly shaped recesses 30. As appears in particular from fig 9 the parts of a block 29 bounding the recess 30 at its sides are provided with an upper face, which has a part 35 extending at least substantially perpendicularly to the longitudinal direction of the locks, and a part 36 joining said part 35 and sloping upwards in the direction of the tool 7, seen in fig 9. The lower boundary face 37, co-operating therewith, of the plate 26 guiding the lock is similarly bevelled, whilst the bottom end of the other guide plate 25 is located at some distance above the block 29. As is furthermore quite apparent from fig 9 the outer boundary face of the plate 26 extending parallel to the lock is not in contact with the tool 17 in the coupled position. Using this construction, it will be apparent, that when the lock is pressed downwards in the direction according to the arrow A (fig 9) the two wedge faces 36 and 37 will be pressed together in a direction perpendicular to the direction of displacement of the lock and, because said wedge faces 36 and 37 slope upwards from the right to the left, seen in fig 9, a force will be exerted on the connecting piece in the opposite direction of the arrow A. As a consequence the coupling bar 2 will be pressed strongly against the boundary wall of the cavity 32. The coupling bar 2 will thereby butt against said boundary face along a pair of longitudinal boundary lines 38 and 39, the boundary line 39 being located on the oblique face 34. Because the cross-sectional dimension of the cavity 32, due to the oblique face, decreases from said boundary line in the direction of the bottom of said cavity, in upward direction in fig 8, therefore, at the same time a tight clamping of the coupling bar in the relevant cavity will be effected when the coupling bar 2 is pressed into the cavity 32. Consequently it will be apparent that when the locks 24 are pressed downwards, seen in figs 1 and 9, by means of the setting cylinder 18 a rigid, but easily effected and also easily detached connection can be effected between the connecting piece 1 and the tool 27. As will furthermore be apparent from the figures the position of the coupling bar 2 is staggered relatively to the locks in the direction of the tool, seen in side view, as a result of which a compact construction of the coupling mechanism is obtained.

Claims: 1. Device for coupling a tool to pivoting arms of an earthmoving machine or the like, whereby the device comprises a connecting piece, which is provided with coupling ears for pivotally coupling the connect­ ing piece to the arms of the excavator, whilst the connecting piece is provided with at least one lock displaceable in its longitudinal direction by means of an adjusting means provided on the connecting piece, and with a coupling bar extending transversely to the longitu­ dinal direction of the lock, said bar fitting in a cavity bounded by a part of the tool, which is further provided with a recess for accom­ modating the conical end of the lock remote from the coupling bar, such that when the end of the lock is pressed into the recess upon coupling the connecting piece to the tool the coupling bar is pressed into the cavity and the part of the connecting piece located near the end of the lock is pushed in the direction of the tool, characterized in that the connecting piece and the tool are provided with wedge faces, which bear against each other in the position where the connecting piece is attached to the tool and which are orientated such that when the lock is pressed down the wedge faces are pressed together and as a result of that the connecting piece is pushed in the direction of the cavity accommodating the coupling bar. 2. Device according to claim 1, whereby the coupling bar has a round section, characterized in that the cavity accommodating the coupling bar has an unround section along at least part of its circum­ ference, such that when the coupling bar is located in the cavity the coupling bar butts against two longitudinal boundary lines in the cavity, the size of whose cross-section gradually decreases from said longitudinal boundary lines in a direction remote from the connecting piece. 3. Device according to claims 1 or 2, characterized in that two locks are arranged parallel to each other and are mutually connected by a crosshead on which there acts a setting cylinder. 4. Device according to any one of the preceding claims, charac­ terized in that the cavity accommodating the coupling bar is staggered relatively to the face accommodating the locks, in the direction of the tool. 5. Device according to any one of the preceding claims, charac­ terized in that the wedge faces are provided on plates of the connecting piece guiding the locks, and on the faces bounding the recesses that accommodate the ends of the locks.

Inventors: DE HAAN, DIRK
Applicants: METAALWARENFABRIEK A.P. VERACHTERT B.V.
Application year: 1988
Main classification: E02F3
IPC codes: E02F3