Quick-Hitch for Construction Vehicle Tools

Abstract

A quick-hitch for coupling a tool to an excavator arm or to a similar tool manipulator, including two hitch halves that can be latched together and that comprise at least one pair of latching parts with which a displaceable latch is associated, an actuating cylinder being provided for actuating the latch. The actuating cylinder has a mechanical blocking unit for locking the latching position of the bolt, having a lead screw which is in a threaded engagement with the piston and/or the piston rod of the actuating cylinder, so that the piston is only displaceable by turning the lead screw, as well as a releasable anti-rotation device for the lead screw.

Claims

1. A quick-hitch comprising: a first hitch half comprising a first latching part; a second hitch half comprising a second latching part; a latching element actuator configured to actuate a latching element between a latched position where the first hitch half and the second hitch half are latched together, and an unlatched position where the first hitch half and the second hitch half are unlatched; and a blocking device that, upon threadable activation, is configured to: lock the latching element in the latched position; and block actuation of the latching element actuator.

2. The quick-hitch of claim 1, wherein the latching element actuator comprises actuator parts selected from the group consisting of a piston, a piston rod, and a combination thereof; and wherein the blocking device comprises a lead screw that can be placed into threaded engagement with one or more of the actuator parts so that each threadedly engaged actuator part is displaceable only by turning the lead screw.

3. The quick-hitch of claim 2 further comprising a releasable anti-rotation device for the lead screw.

4. The quick-hitch of claim 3, wherein the latching element comprises a bolt configured to be retractable and extractable from one or both of the first latching part and the second latching part by the latching element actuator.

5. The quick-hitch of claim 4, wherein the quick-hitch is configured to couple a tool to a tool manipulator.

6. The quick-hitch of claim 5, wherein either: the releasable anti-rotation device is arranged within a cylinder of the latching element actuator, and the releasable anti-rotation device and the lead screw are mounted so as to be axially adjustable relative to each other and can be brought into and out of latching engagement by axial adjustment relative to each other; or the releasable anti-rotation device is mounted on the latching element actuator so as to be axially movable but rotationally fixed, and the lead screw is mounted in the latching element actuator so as to be rotatable but axially fixed.

7. A quick-hitch for coupling a tool to a tool manipulator comprising: two hitch halves that are latchable to one another by a latching element comprising a bolt that is retractably and extractably associated with the two hitch halves, wherein a first hitch half of the two hitch halves comprises a first latching part and a second hitch half of the two hitch halves comprises a second latching part; a latching element actuator comprising an actuating cylinder, the actuating cylinder configured to actuate the bolt between a latched position where the first hitch half and the second hitch half are latched together, and an unlatched position where the first hitch half and the second hitch half are unlatched; a blocking device for locking the bolt in the latched position; and anti-rotation device; wherein the actuating cylinder comprises a piston and a piston rod; wherein the blocking device comprises a lead screw that can be placed into threaded engagement with a piston and/or a piston rod of the actuating cylinder so that the piston can only be displaceable by turning the lead screw; and wherein the anti-rotation device comprises a releasable anti-rotation device for the lead screw.

8. The quick-hitch of claim 7, wherein the releasable anti-rotation device comprises a locking ring that extends in a plane transverse to a longitudinal axis of a cylinder of the actuating cylinder and is guidedly axially movably in a longitudinal direction of the actuating cylinder, fixed in rotation on the cylinder.

9. The quick-hitch of claim 7, wherein the releasable anti-rotation device is arranged within a cylinder of the actuating cylinder; and wherein the releasable anti-rotation device and the lead screw are mounted so as to be axially adjustable relative to each other and can be brought into and out of latching engagement by axial adjustment relative to each other.

10. The quick-hitch of claim 7, wherein the releasable anti-rotation device is mounted on the actuating cylinder so as to be axially movable but rotationally fixed; and wherein the lead screw is mounted in the actuating cylinder so as to be rotatable but axially fixed.

11. The quick-hitch of claim 7, wherein the releasable anti-rotation device is configured to lock on one side only in one direction of rotation.

12. The quick-hitch of claim 7 further comprising a preloading device for biasing the releasable anti-rotation device in a latching position where the bolt is in the latched position.

13. The quick-hitch of claim 7 further comprising an adjusting device for axially adjusting the releasable anti-rotation device; wherein the adjusting device comprises at least one separate adjusting element that can be driven axially and axially adjusts the releasable anti-rotation device.

14. The quick-hitch of claim 7, wherein the actuating cylinder is accommodated in an interior space of the first hitch half and is enclosed by hitch walls when the first hitch half and the second hitch half are latched together.

15. The quick-hitch of claim 7, wherein the first hitch half further comprises a third latching part; wherein the second hitch half further comprises a fourth latching part; wherein the two hitch halves are couplable to each other at the third and fourth latching parts; wherein the first and second latching parts are engageable and/or lockable by pivoting the two hitch halves together about the third and fourth latching parts; and wherein the bolt is associated with the first and second latching parts.

16. The quick-hitch of claim 7 further comprising two receiving jaws, a first receiving jaw of the receiving jaws being formed open to a side opposite to the other receiving jaw, and a second receiving jaw of the receiving jaws being formed open in a circumferential direction on an arc around the first receiving jaw.

17. The quick-hitch of claim 8, wherein the locking ring has a circumferential contour deviating from a circular shape and is received in an installation space in an interior of the actuating cylinder; and wherein the actuating cylinder has an inner circumferential wall deviating from a circular shape and adapted in shape to the locking ring on which the locking ring is guided axially displaceably and is secured against rotation.

18. The quick-hitch of claim 8, wherein the locking ring comprises locking ring latching elements selected from the group consisting of latching claws, latching recesses, and combinations thereof, the locking ring latching elements distributed in a circumferential direction, which in the case of latching claws project towards the lead screw, and in the case of latching recesses are recessed away therefrom.

19. The quick-hitch of claim 12, wherein the preloading device comprises spring elements that act on the releasable anti-rotation device with axially acting spring forces.

20. The quick-hitch of claim 13, wherein the at least one separate adjustment element comprises a plunger piston received in a bore in a cylinder wall and adjustable by pressurization.

21. The quick-hitch of claim 15, wherein the actuating cylinder is arranged at an acute angle inclined with respect to a plane defined by two pairs of latching parts, one pair being the first and second latching parts, and another pair being the third and fourth latching parts; and wherein a longitudinal axis of the actuating cylinder passes opposite sides of the two pairs of latching parts.

22. The quick-hitch of claim 18, wherein the latching claws comprise a lock on one side and have latching flanks that are directed in a circumferential direction towards opposite sides and which are differently formed.

23. The quick-hitch of claim 12, wherein the latching flanks are perpendicular towards one circumferential direction and have flanks that rise in a wedge shape towards the opposite circumferential direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying Figures, which are incorporated in and constitute a part of this specification, illustrate several aspects described below.

[0061] FIG. 1 is a schematic side view of a quick-hitch according to an advantageous embodiment of the invention, which quick-hitch is attached to a jib arm of an excavator and a grab bucket is coupled as an add-on tool.

[0062] FIG. 2 is a perspective view of the quick-hitch from FIG. 1 in an uncoupled position in which the two hitch halves that can be coupled together are shown shortly before being hooked onto the hook portion.

[0063] FIGS. 3A and 3B are each a perspective view of the two hitch halves, showing energy coupling parts attached to each hitch half, wherein partial view FIG. 3A shows the hitch half which is mounted on the excavator arm and on which a coupling carrier is rigidly mounted, and partial view FIG. 3B shows a tool-side hitch half on which a coupling carrier is mounted in a rubber-elastic manner.

[0064] FIG. 4 is a perspective view of the two hitch halves in the state when coupled together but not yet pivoted together.

[0065] FIG. 5 is a perspective, partially cutaway view of the quick-hitch showing the arrangement of the actuating and locking cylinder for actuating the latch for the second latching bolt, wherein partial view a shows the actuating and locking cylinder in interaction with the quick-hitch halves and the grab bucket attached thereto, and partial view b is an enlarged, cutaway view of the actuating and locking cylinder.

[0066] FIG. 6 is a perspective longitudinal sectional view of the actuating and locking cylinder of the preceding FIGS.

[0067] FIG. 7 is a partial, enlarged perspective longitudinal sectional view of the anti-rotation device for the lead screw of the actuating and locking cylinder.

[0068] FIG. 8 is a perspective view of the anti-rotation element for locking the lead screw.

DETAIL DESCRIPTION OF THE INVENTION

[0069] To facilitate an understanding of the principles and features of the various embodiments of the invention, various illustrative embodiments are explained below. Although exemplary embodiments of the invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways.

[0070] As used in the specification and the appended Claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include a composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named.

[0071] In describing exemplary embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

[0072] Ranges may be expressed as from “about” or “approximately” or “substantially” one value and/or to “about” or “approximately” or “substantially” another value. When such a range is expressed, other exemplary embodiments include from the one value and/or to the other value.

[0073] Similarly, as used herein, “substantially free” of something, or “substantially pure”, and like characterizations, can include both being “at least substantially free” of something, or “at least substantially pure”, and being “completely free” of something, or “completely pure”.

[0074] “Comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.

[0075] The characteristics described as defining the various elements of the invention are intended to be illustrative and not restrictive. For example, if the characteristic is a material, the material includes many suitable materials that would perform the same or a similar function as the material(s) described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, for example, materials that are developed after the time of the development of the invention.

[0076] As shown in FIG. 1, the quick-hitch 1 can be mounted between the free end of the jib arm 5 of an excavator 30 and the add-on tool 4 that is to be attached thereto, wherein the add-on tool 4 can be designed for example as a grab bucket, as is shown in FIG. 1, but which can, in a manner conventional per se, also comprise other construction, handling or demolition tools, for example in the form of clamshell buckets, demolition jaws, pincers, or the like.

[0077] In this case, the quick-hitch 1 can be able to be mounted on the jib arm 5, by means of the (arm-side) hitch half 2, so as to be pivotable about a horizontal pivot axis that is oriented transversely to the longitudinal axis of the jib arm 5, such that the quick-hitch 1, together with the add-on tool 4 attached thereto, can be pivoted relative to the jib arm 5 for example by means of a pressure medium cylinder 36 and an interposed pivot piece 37.

[0078] A (tool-side) hitch half 3 (cf. FIG. 2) can be attached to the add-on tool 4 and/or an interposed rotary drive.

[0079] As shown in FIG. 2, the two hitch halves 2 and 3 comprise two pairs of latching parts that can be latched together and that allow for a two-stage coupling or latching process. Firstly, one pair of latching elements is hooked in or coupled, in order to then pivot the two hitch halves together about the coupled first latching pair. In the pivoted-together coupling position, the second pair of latching parts are then latched together, cf. a comparison of FIGS. 4 and 5.

[0080] As shown in FIG. 2, one hitch half, in particular the (arm-side) hitch half 2, can comprise, as latching parts, a coupling receptacle 6 and a latch 11 that can be moved in front of the opening of a latching receptacle 10, wherein the latching receptacle 10 can have a different opening direction from the coupling receptacle. In particular, the coupling receptacle 6 can be open in the direction facing away from the latching receptacle 10, while the latching receptacle 10 can be designed so as to be open towards the (tool-side) hitch half 3. However, as an alternative to the embodiment shown in the FIGS., according to FIG. 2, the second latching part of the hitch half 2 could also comprise a latching jaw that is displaceable as a whole, as is known per se. The latch 11 can be displaceable approximately in a direction transversely to the opening of the latching receptacle 10, in order to be able to be pushed in front of the opening. For example, the latch 11 can be moved into the latching receptacle 10 from above, so as to be slightly obliquely inclined.

[0081] The other hitch half, in particular the (tool-side) hitch half 3, can comprise two transverse bolts 33 and 34 as latching parts which can be oriented so as to be in parallel with one another and mutually spaced to such an extent that they fit into the openings of the coupling and latching receptacles 6 and 10.

[0082] In order to couple the two hitch halves 2 and 3 together, firstly the coupling receptacle 6 is suspended on the transverse bolt 33, wherein a securing element 7 can capture or secure the transverse bolt 33 in the coupling receptacle 6 in order to prevent the bolt from inadvertently slipping out when the two hitch halves 2 and 3 are pivoted together. The securing element 7 can for example be spring-preloaded and opened by a pressure actuator when the quick-hitch is intended to be decoupled.

[0083] If the coupling receptacle 6 is suspended on the transverse bolt 33, as is shown in FIG. 4, the two hitch halves 2 and 3 can be pivoted towards one another about the pivot axis formed by the suspended coupling receptacle 6 or the transverse bolt 33 captured therein, as far as the coupling position shown in FIG. 5. In the mentioned coupling position according to FIG. 5, the second transverse bolt 34 is inserted into the latching receptacle 10 such that the latch 11 can be moved into the latching position in order to secure or fix the transverse bolt 34 in the latching receptacle 10. The latch 11 is actuated by actuating cylinder 8, being a pressure fluid cylinder 8, which will be discussed in further detail below.

[0084] As shown in FIGS. 4 and 5, energy coupling parts 12 and 13 can be provided on a portion of the hitch halves 2 and 3 that is spaced apart from the coupling receptacle 6, which energy coupling parts can in particular be arranged on an end portion of the hitch halves 2 and 3 that is opposite the coupling receptacle 6.

[0085] The energy coupling parts 12 and 13 can be hydraulic couplings for example. Irrespective thereof, the energy coupling parts 12 and 13 can be designed as plug-in couplings which can be moved into one another and can comprise coupling sleeves and coupling pins that can be inserted therein.

[0086] As FIG. 5 shows, it may be advantageous for the actuating cylinder 8 to be connected by its piston rod 9 to the latch 11 and to be supported and/or fixed to the hitch half 2 by its cylinder 12, from which the piston rod 9 is extractable. For example, the hitch half 2 may comprise the energy coupling part 13 comprising a receiving pocket 13 in which the energy coupling part 12 comprising a cylinder 12 is seated, wherein a support 14 may be provided at one end of the receiving pocket 13 against which the cylinder 12 may be axially supported. In principle, however, the actuating cylinder 8 could alternatively or additionally be bolted to the hitch half 2, for example, whilst a corresponding bearing eye could be provided on the cylinder 12.

[0087] As FIG. 5 shows, the actuating cylinder 8 may be inclined at an acute angle to a plane defined by the two coupling and latching receptacles 6 and 10, in particular transverse pin axes passing therethrough, so that the longitudinal axis of the actuating cylinder 8 passes on opposite sides of the coupling and latching receptacles 6 and 10. In particular, the actuating cylinder 8 may have an end portion positioned above the coupling receptacle 6, while the latch-side end of the cylinder 12 or the latch 11 may be positioned below the latching receptacle 10.

[0088] Overall, the actuating and locking cylinder 8 has a protected receptacle in an interior of the hitch half 2 and, in the coupled state of the quick-hitch 1, is enclosed by the outer peripheral contours or walls of the hitch halves 2 and 3 and is thereby protected. In particular, the lateral frame plates of the hitch halves 2 and 3 may laterally enclose the actuating cylinder 8.

[0089] As shown in FIGS. 5 to 8, a blocking or locking unit 15 is integrated into the actuating cylinder 8, which can fix the actuating cylinder 8 in one or more extension positions and, in particular, arrest the latch 11 in its latching position.

[0090] In this respect, the blocking or locking unit 15 can comprise a mechanical blocking device 15 of the actuating cylinder 8 comprises a lead screw 16 which can be housed in the interior of the cylinder 12 and can be in threaded engagement with the piston 17 and/or the piston rod 9 of the actuating cylinder 8. For example, as FIG. 7 illustrates, the piston 17 may have an internal screw thread which is in screw engagement with an external thread of the lead screw 16 so that axial movement of the piston 17 involves rotation of the lead screw 16. The piston 17 is moved in the cylinder 12 in a manner known as such by pressurization, wherein the actuating cylinder 8 can advantageously be of double-acting design. Depending on whether the annular chamber 18 surrounding the piston rod 9 or the pressure chamber 19 facing away from the piston rod 9 is pressurized with pressure medium, the piston 17 retracts or extends. The piston 17 is guided in a non-rotatable manner, for example via the piston rod 9, which can be secured against rotation by its attachment to the latch 11 or also by the corresponding configuration of the outlet opening on the cylinder collar. Hereby an axial movement of the piston 17 leads to a rotation of the lead screw 16.

[0091] The lead screw 16 may be axially fixed but rotatably mounted in the cylinder 12, for example by means of a lead screw head 20 which may be non-rotatably connected to the lead screw 16 and rotatably mounted in the cylinder 12.

[0092] Due to the screw engagement between piston 17 and lead screw 16 and their bearings, piston 17 can only be moved axially if lead screw 16 can rotate. In order to lock the actuating cylinder 8, i.e. to freeze the piston 17 in its respective axial position, the lead screw 16 can be fixed against rotation by means of an anti-rotation device 21 which can block the rotational degree of freedom of the lead screw 16.

[0093] For this purpose, the anti-rotation device 21 comprises an anti-rotation element 22 which is also received in the cylinder 12 and is axially displaceable therein, but is rotationally fixed, so as to be brought into and out of latching engagement with the lead screw 16 or the lead screw head 20 connected thereto by axial displacement.

[0094] As FIG. 8 shows, the anti-rotation element 22 may advantageously comprise an at least approximately plate-shaped locking ring 23 which may embrace the lead screw head 20 and extend transversely to the longitudinal direction of the actuating cylinder.

[0095] In this regard, the locking ring 23 is axially slidably received in an installation space 24 which may form part of the cylinder 12. In order to secure the locking ring 23 against rotation, but to keep it axially displaceable, the locking ring 23 may have an outer contour deviating from the circular shape, for example by having one or more flattenings at the circumference and/or an overall oval and/or elliptical or polygon-like multi-angular design. In a corresponding manner, the installation space 24 may have an inner circumferential contouring deviating from the circular shape, for example having one or more flattenings and/or having an oval or elliptical or polygon-like multi-angular corresponding to the contouring of the locking ring.

[0096] Advantageously, the pairing of the outer and inner circumferential surfaces of the locking ring 23 and the installation space 24 simultaneously forms a displacement guide and an anti-rotation device, and in particular a (not circular) cylindrical contouring in the manner of a prism can be provided.

[0097] However, as an alternative or in addition to anti-rotation via the circumferential walls, separate longitudinal sliding guide elements could also be provided, for example in the form of longitudinal rods parallel to the longitudinal axis of the cylinder, which can engage in guide recesses 25 on the anti-rotation element 22, for example in the form of guide grooves open towards the outer circumference, as shown in FIG. 8.

[0098] The anti-rotation element 22, which may be in the form of the locking ring 23 shown, could in principle be axially adjusted by the application of pressure, a corresponding pressure chamber being formed by the installation space 24. Alternatively, however, separate displacement elements may be provided, for example in the form of plunger pistons, the displacement of which results in an axial displacement of the locking ring 23 or the anti-rotation element 22. For this purpose, for example, bores can be provided in a cylinder wall, in which the plunger pistons 27 are accommodated, so that they can be moved by pressurizing the bores in order to thereby axially displace the locking ring 23.

[0099] In this regard, the anti-rotation element 22 may be biased into the latching position by a preloading device, wherein the preloading device may comprise, for example, one or more spring means for urging the locking ring 23 axially into the latching blocking position by spring force.

[0100] In order to lock the threaded screw 16, provision can be made on the latching element and the lead screw head 20 for interlocking latching contours, in particular in the form of latching claws 29 and latching recesses adapted thereto in terms of shape, into which the latching claws 28 can retract. The latching claws 28 and the cooperating latching recesses may be provided on the locking ring 23 and the lead screw head 20, in particular projecting or machined in the axial direction. For example, provision can be made on the locking ring 23 for a plurality of axially projecting latching claws 28 distributed in the circumferential direction, which can enter latching recesses in an end face of the lead screw head 20 facing the locking ring 23.

[0101] As FIG. 8 shows, the latching contours can be configured to lock reliably on one side or in one direction only, wherein the latching claws 28 can have flanks which rise in a wedge shape towards one side and can thus be driven over, while locking flanks, for example perpendicular to the circumferential direction, can be provided on the opposite side. This makes it possible to continue turning the lead screw in one direction even when the locking ring 23 is actually preloaded into the latching position, wherein the latching connection continues slipping. In the opposite direction, however, the lead screw is reliably locked.

[0102] Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structure and function. While the invention has been disclosed in several forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions, especially in matters of shape, size, and arrangement of parts, can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims. Therefore, other modifications or embodiments as may be suggested by the teachings herein are particularly reserved as they fall within the breadth and scope of the claims here appended.