COUPLING UNIT FOR MACHINERY

Abstract

 The current invention pertains to a coupling unit designed for tool exchange that can be connected to a machine. The coupling unit comprises a frame (4) and an actuator device (6). The frame (4) includes a first side (14) with a hook-shaped cutout (26) for receiving a front axle (10) of the tool (2) and a second side (16) with a recess (28) for receiving a rear axle (12) of the tool. The actuator device (6) consists of a housing (20) with a first set of adapters (34) that can connect to a second set of adapters (8) on the tool (2). The housing (20) also contains at least one actuator (22) embedded on one side that can extend and retract along an actuator axis (a). At least one lock finger (24) connected to the housing (20) on a second side opposite the first side moves along the actuator axis (a) upon retraction or extension of the actuator (22). This movement changes the shape of the recess (28) and locks the rear axle (12) of the tool upon extension of the actuator (22). The height (h) and width (w) of a cross section of the lock finger (24) upfill the equation w < h and h is measured in a direction perpendicular to a plane (p) defined by the frame (4).

Description

Technical Field

[0001] The present invention pertains to the field of machinery, such as forestry machines, constructions machines or industrial machines, and specifically to a coupling unit designed for the exchange of tools. This coupling unit, which can be connected to a machine, for example a machine arm, includes a frame and an Actuator device. The frame is designed to accommodate the front and rear axles of the tool, while the actuator device includes a housing with hydraulic adapters for connection to corresponding adapters on the tool. The actuator device also features at least one hydraulic cylinder and lock finger, which work in coordination to lock the tool's rear axle in place and therewith lock the tool to the machine.

Background of the Invention

[0002] The construction industry has seen a myriad of advancements in technology and machinery. Machines used in this field are often multi-purpose, able to carry out various tasks by changing the tool or attachment at the arm or end of the machine. For instance, a single machine might be capable of digging, lifting loads, drilling, hammering, compacting and more based on the tool attached to it. To enable this functionality, these machines need an efficient coupling unit that can swiftly and securely connect different tools to the machine.

[0003] Conventionally, such coupling units comprise a frame which can be connected to the machine. The frame generally includes two sides: a first side equipped with a hook-shaped cutout designed to receive a front axle of the tool, and a second side comprising a recess configured to receive a rear axle of the tool. These two sides are typically arranged opposite one another to match the arrangement of front - and rear axle of the tool.

[0004] In addition to this basic structure, prior art coupling units also incorporate hydraulic systems for automated control and manipulation of tools and for locking the tool to the machine. An actuator device is commonly included as part of this hydraulic system. The actuator device typically includes a housing that contains a set of hydraulic adapters meant for connection with a corresponding set of adapters on the tool.

[0005] The actuator device typically also comprises a pair of hydraulic cylinders lodged within a pair of apertures in the housing. This pair of hydraulic cylinders is configured such that one side of each cylinder is embedded in the aperture while a rod side end attaches to the frame structure. This allows for extension and retraction along one side of the housing and thereby moving the housing and the hydraulic adapters along a cylinder axis.

[0006] In order to lock a rear axle of the tool a pair of lock finger is attached on one side of the housing so that they moves along the cylinder axis with changes in position by the hydraulic cylinder (extension or retraction). Upon extension of the pairs of hydraulic cylinders the pair of lock fingers change the shape of the recess thereby locking the rear axle of the tool in a form fitting manner.

[0007] Despite these functional features, conventional technologies have often been limited due to their specific designs or material properties leading to difficulties during application such as inefficient lock-in mechanisms or conflicts during adapter alignment, which will now be described referring to figures 1 to 3b.

[0008] Typically, tools are connected to machines following a pre-defined coupling sequence, which might be the following sequence (exemplary):

1. Extend the pair of hydraulic cylinders,

2. Connect front axle of the tool to a hook shaped cutout,

3. Tilting coupling unit so that the lock fingers come to rest on the rear axle,

4. Retracting the pair of hydraulic cylinders,

5. Tilting coupling unit so that the rear axle is snug embedded in the recess,

6. Extension of the pair of hydraulic cylinders for locking the rear axle and therewith the tool in place.

[0009] A decoupling sequence may follow the above steps but in reverse order.

[0010] The prior art will now be described referring to figures 1 to 3b.

[0011] Figure 1 illustrates a coupling unit 1' according to the prior art connected to a tool 2 and a machine arm 3 or the like. The coupling unit 1' is fixedly connected to the machine arm 3 using bolts 5 that are part of the machine arm 3 and holes or openings 32 in a flange 18 of the coupling unit 1'. Figure 1 further illustrates a rear axle 12 and a front axle 10 of the tool 2. In the example of figure 1 the tool 2 is connected to the coupling unit 1' but parts of the tool 2 are cut off for illustrative purposes. Hydraulic lines 11 of the tool 4 extend into the coupling unit 1' for connection with the latter and therewith for connection with the adapters of the coupling unit 1'. In the illustration in figure 1 the tool 2 may for example be a hydraulic hammer or the like.

[0012] The coupling unit 1' comprises a frame 4' and an actuator device 6' at least partially embedded in the frame 4'.

[0013] Turning now to figures 2a and 2b the coupling unit is explained in more detail referring to the frame 4' and the actuator device 6'. The frame 4' comprises a first side 14' and a second side 16'. At the first side 14' a recess 28' is arranged, whereby the recess 28' comprises a feed through 30' for receiving lock fingers 24' of the actuator device 6'. The lock fingers 24' are designed to extend and retract through the feed throughs 30' in order to thereby change the shape of the recess 28'. The actuator device 6' comprises a housing 20' having a first set of hydraulic adapters 34'. The hydraulic adapters 34' are embedded in a machined block of the housing 20'. From figures 2a and 2b it can be seen that the lock fingers 24' have a circular cross section.

[0014] Figures 3a and 3b illustrate cross sectional side views, along a direction of arrow III of figure 2b, of the coupling unit 1' with some parts removed for illustrational purposes.

[0015] Figure 3a illustrates part of the tool 2 with its front axle 10 and rear axle 12, whereby the front axle 12 is already connected to the hook shaped cutout 26' (figure 3b) of the coupling unit 1'. The Actuator device 6' comprises actuators 22', which are hydraulic cylinders in the examples of figures 1 to 3b. In the illustration in figure 3a the actuators 22' are in the extended state and the coupling unit 1' is in the sequence 3 of the above-described coupling sequence, namely the lock fingers 24' rest on the rear axle 12 while the front axle 10 is engaged in the hook shaped cutout 26'. From figure 3a it is well visible how the housing 20' or the H-cylinder device 6' in general gets in conflict with a second set of hydraulic adapters 8 on the tool 2 during this coupling sequence. In other words the housing 20', in particular that part of the housing 20' that comprises the first set of hydraulic actuators 34' is in conflict with the first set of hydraulic actuators 8 and may destroy them or bend them during this coupling sequence step. This may in particular be the case if many hydraulic adapters need to be fitted into the first set of hydraulic adapters and space for such a number of hydraulic adapters needs to be provided.

[0016] For the sake of completeness figure 3b illustrates the coupling unit 1' being securely coupled to the tool 2 or vice versa with the first set of hydraulic adapters 8 and the second set of hydraulic adapters 34' being connected to one another.

Summary of the Invention

[0017] In view of the above an object of the present invention is to provide a coupling unit 1' that is more versatile and efficient.

[0018] Another object of the present invention may be to provide a coupling unit that can accommodate a higher number of adapters for connecting to adapters of the tool.

[0019] In view of the above-mentioned problems the inventor of the present invention has discovered that it is possible to change the cross-sectional shape of the actuators and/or the lock fingers in order to provide more space, in particular more height, for either a higher number of adapters or bigger adapters in a housing of the actuator device, without creating a potential conflict and therewith destruction of adapters during a coupling between the tool and the coupling unit. The inventor further realized that this is beneficial when using hydraulic adapters, since greater dimensions of hydraulic adapters provide better efficiency and less loss in system pressure during coupling. The gained space for adapters may however also be useful when electric adapters or the like are used, making space for extra equipment such as for example cameras or redundancy adapters/connections of electric or hydraulic nature.

[0020] Disclosed herein is a coupling unit for exchanging a tool, the coupling unit being connectable to a machine and comprising a frame and an actuator device, the frame comprises:

• a first side comprising a hook shaped cutout, the hook shaped cut out being arranged to receive a front axle of the tool, and
• a second side comprising a recess, the recess being arranged to receive a rear axle of the tool, the first side and the second side being arranged opposite one another and the second side further comprising a feed through at the recess.

[0021] The actuator device comprises:

• a housing comprising a first set of adapters arranged to connect to a second set of adapters arranged on the tool, the housing further comprising a at least one aperture,
• at least one actuator embedded with one side in the at least one aperture and connected to the frame with a free end, so that the actuator can extend and retract on a first side of the housing along an actuator axis (a), whereby the first set of adapters are arranged to connect with the second set of adapters along the actuator axis (a),
• at least one lock finger connected to the housing on a second side opposite the first side of the housing so that the at least one lock finger moves along the actuator axis (a) and within the feed through upon retraction or extension of the at least one actuator cylinder, so that the at least one lock finger can change the shape of the recess and thereby lock the rear axle of the tool upon extension of the at least one actuator upon movement.

[0022] A height (h) and a width (w) of a cross section of the at least one lock finger as seen in a plane perpendicular to the actuator axis (a) upfill the equation w < h, thus the width (w) is smaller than the height (h) and wherein the height (h) is measured in a direction perpendicular to a plane (p) defined by the frame.

[0023] In view of the above the frame is designed with two sides. A first side incorporates a hook-shaped cutout, primed to receive a front axle of the tool, while a second side accommodates a recess for the rear axle of the tool. The two sides are positioned opposite each other with an additional feed-through at the recess on the second side.

[0024] The actuator device forms an integral part of the coupling unit. It comprises a housing which houses a set of adapters that connect with corresponding adapters on the tool. The housing also includes at least one opening or aperture where one end of an actuator embeds itself while its free end connects to the frame allowing it to extend and retract on one side of the housing, aligning its motion along a cylinder axis. This arrangement allows for seamless connection between sets of adapters upon coupling of a tool to the coupling unit.

[0025] The actuator device also comprises at least one lock finger attached to and expending from another side of the housing, ensuring it moves in sync with any extension or retraction movement made by the actuator. This design allows for changes in shape at the recess thereby locking the rear axle upon actuator's extension.

[0026] As explained above a distinguishing feature here lies in dimensions namely height and width pertaining to cross section area, seen from plane perpendicular to the actuator axis, for the at least one lock finger, whereby the width measured is lesser than height with height being measured in direction perpendicular to plane defined by frame.

[0027] The actuator device may be an H-cylinder device.

[0028] The above-described coupling unit has the advantage that it can be used with bigger or a higher number of adapters in the housing of the actuator device. Similarly, the adapters of the tool may be formed and designed accordingly and bigger adapters or adapters with greater cross section may be employed and used without the risk of leading to conflicts and damages during the coupling and decoupling sequence. This is no possible today with the state of the art coupling units.

[0029] The coupling unit may be a quick coupling unit or a tilt rotator unit/tilt rotator.

[0030] The above may increase efficiency usability of the coupling unit.

[0031] In an embodiment a free end of the at least one lock finger may comprise a lock finger recess arranged to change the shape of the recess upon extension of the at least one actuator.

[0032] The lock finger recess may be designed to have at least one flat surface intended to engage the rear axle of the tool. This may improve the coupling between the coupling unit and the tool.

[0033] Further in an embodiment some thought has been given when considering distance measurement from free end of lock finger towards set of adapters provided on housing's first side so as not cause conflict when aligning both sets adapters, thus the ones on the tool and the ones on the coupling unit during coupling process.

[0034] In particular a distance as measured from a free end of the at least one lock finger to the first set of adapters may be chosen so that the first set of adapters can move into an aligned position with the second set of adapters without getting in conflict with the second set of adapters upon coupling of the coupling unit to the tool.

[0035] The above may reduce the risk of damages and conflicts during coupling and decoupling between coupling unit and tool.

[0036] In embodiments the lock finger's cross-sectional shape deviates from circularity.

[0037] For example the cross-sectional shape or form may have a rectangular form with rounded edges or even an oval shape in some instances.

[0038] In particular the lock finger may have a non-circular cross section.

[0039] In another embodiment the lock finger may have an oval shape.

[0040] According to the above the cross-sectional shape of the feed through in the second side of the frame may be adapted to the cross-sectional shape of the lock fingers.

[0041] In an embodiment there may be variations in the frame and Actuator device designs, where the frame includes two feed throughs, and the Actuator device incorporates two actuators and lock fingers. The housing on these versions has an H-shaped design where each leg of the 'H' includes an opening for accommodating one of the two actuators.

[0042] In particular the frame may comprise two feed throughs and the actuator device may comprise two actuators and two lock fingers, whereby the housing has an H-shape and wherein each leg of the H-shape comprises an aperture for receiving one of the two actuators.

[0043] A leg of the of the H-shape is basically defined by one actuator whereby the two legs are interconnected by a web, in which web the first set of adapters are arranged.

[0044] The above design improves stability and robustness of the coupling unit.

[0045] In an embodiment herein the adapters on both the coupling unit and the tool can be hydraulic in nature. In this scenario, the first set of hydraulic adapters may exhibit female characteristics and the second set of hydraulic adapters may exhibit male characterises or vice versa.

[0046] In light of the above each set of adapters may have blended adapters male and female ones, with corresponding female and male ones on the other set.

[0047] Moreover, actuators could either be hydraulic cylinders or electrically charged ones or in a wider variant even pneumatic cylinder.

[0048] The adapters may also be electric adapters (of female and male type), similar to the above description of the first - and second set of hydraulic adapters.

[0049] In summary, the inventive design addresses problems faced by existing systems. By altering cross-sectional shapes of actuators and/or lock fingers more space is made available for accommodating a higher number of adapters or larger ones within the actuator device's housing without potential conflicts or destruction during tool-unit coupling process. This proves beneficial particularly while using hydraulic adapters as bigger dimensions contribute towards improved efficiency and lesser loss in system pressure during coupling process. The additional space created may also accommodate additional equipment like cameras or redundancy adapters/connections of electric or hydraulic nature which adds to versatility of this invention.

[0050] The invention will now be described in more detail referring to figures 4a to 6c.

Brief Description of the Drawings

[0051] The present invention will now be described, for exemplary purposes, in more detail by way of an embodiment(s) and with reference to the enclosed drawings, in which:

Fig. 1

illustrates a coupling unit according to the prior art mounted to a machine arm and connected to a tool,

Fig. 2a

illustrates a coupling unit according to the prior art with some parts removed for illustrative purposes,

Fig. 2b

illustrates an orthogonal front view of the coupling unit of figure 2a,

Fig. 3a

illustrates a cross sectional view of the embodiment shown in figures 2a and 2b during coupling of the coupling unit to a tool,

Fig. 3b

illustrates a similar view as figure 3a with the tool firmly coupled to the coupling unit,

Fig.4a

schematically illustrates a coupling unit with removed parts according to the invention,

Fig. 4b

schematically illustrates an orthogonal front view of the coupling unit of figure 4a,

Fig. 5a

schematically illustrates an actuator device according to the invention, with the actuators in a retracted position,

Fig. 5b

schematically illustrates the actuator device of figure 5a with the actuators in an extended position; and

Fig. 6a to 6c

schematically illustrate the coupling sequence of the coupling unit according to the invention to the tool.

Detailed Description

[0052] The invention will now be described referring to figures 4a to 6c. In figures 4a to 5b, the basic structure and features of the coupling unit 1 will be described and in figures 6a to 6d a coupling sequence is schematically illustrated including beneficial technical effects of the invention.

[0053] Figure 4a illustrates a coupling unit 1 according to the invention comprising a frame 4 and an actuator device 6. The frame 4 comprises a first side 14 and a second side 16, at the first side 14 a hook shaped cutout 26 is arranged, the hook shaped cutout 26 being designed to receive a front axle 10 of the tool 4 (not illustrated in figure 4a) and at the second side 16 a recess 28 is arranged, the recess 28 being designed to receive a rear axle 12 of the tool 4 (not illustrated in figure 4a). The second side 16 further comprises feed throughs 30 in which locking fingers 24 are movable embedded. The lock fingers 24 form part of the actuator device 6, which is explained in more detail referring to figures 5a and 5b. In figure 4a the lock fingers 24 are illustrated in their extended position.

[0054] The lock fingers 24 arranged so that they are embedded on peripheral sides of the frame 4, which leaves space for a housing 20 of the actuator device 6 in between the lock fingers 24. The housing 20, in particular the part that is visible in figure 4 interconnecting the two lock fingers 24 may be called web and comprises a first set of adapters 34, in the illustrated example a set of hydraulic female adapters 34. The first set of adapters 34 is configured to connect to a second set of adapters 8 on the tool 2 (c.f. figures 5a to 6d).

[0055] From figures 4a and 4b it can be seen that the lock fingers 24 do not have a circular cross section as the ones according to the prior art illustrated referring to figures 1 to 3b. The lock fingers have an oval cross section or a cross section in which a height h is greater than a width w, when the height is measured perpendicular to a plane p defined by the frame 4 of the coupling unit 1. The cross-sectional shape of the lock fingers 24 may have straight sides and rounded tops and bottoms as illustrated in figure 4b.

[0056] Turning now to figures 5a and 5b, which illustrate an actuator device 6 or an H-cylinder device 6, the actuator device 6 is explained in more detail. Further, figures 5a and 5b illustrate a part of a hydraulic system of the tool 2 with hydraulic lines 7 and hydraulic adapters 8 connected thereto. These hydraulic lines 7 and the second set of hydraulic adapters 8 are illustrated for understanding purposes, with the rest of the tool removed. Figures 5a and 5b illustrate how the connection between the first set of hydraulic adapters 34 and the second set of hydraulic adapters 8 take place.

[0057] Figure 5a illustrates the actuator device 6 comprising a housing 20 and a pair of actuators 22 embedded in apertures 22 of the housing 20. The housing 20 is shaped in a H-shape with a web 20a with two legs 20b. In the web 20a of the housing a first set of hydraulic adapters 34 are arranged. In figure 5a it is well I visible how the first set of adapters or hydraulic adapters 34 are not connected to the second set of adapters 8 or hydraulic adapters yet, since the actuators 22 are in the retracted position. On a first side of the housing 20, a piston rod 40 is arranged for extension and connection to the frame (not shown in figures 5a and 5b) with its free end 44. On a second side of the housing 20 the lock fingers 24 are arranged and embedded in the feed throughs 30 (illustrated in figures 4a and 4b).

[0058] Barrels 42 of the actuators 22 are arranged in apertures 38 of the housing 22, and fixedly connected thereto so that the entire housing 20 is moving along an actuator axis a (figure 5b) upon extension and retraction of the actuators 22. In this manner figure 5b illustrates the actuators in the extended state with the piston rods 40 extended and the first set of adapters 34 connected to the second set of hydraulic adapters 8 of the tool. In this configuration as illustrated in figure 5b, the lock fingers 24 change the shape of the recess 28 for locking a rear axle 12 of the tool 2 (c.f. figure 6d). The lock fingers 24 may comprise a lock finger recess 46 or surface 46, which is designed to interact with the rear axle 12 upon locking of the tool 2 in the coupling unit 1.

[0059] Turning now to figures 6a and 6d, which illustrate a coupling sequence between the coupling unit 1 and the tool 2, the invention is further explained.

[0060] Figure 6a illustrates the actuators 22 in the extended position with the front axle 10 of the tool 2 snug embedded in the hook shaped cut out 26. The lock fingers 24 thereby rest on the rear axle 12 of the tool 2 and due to the increased height (h) of the lock fingers 24 the first set of hydraulic adapters 34 and/or the web 20b of the housing 20 does not get into conflict with the second set of adapters 8 on the tool 2 and thereby damages are prevented. As explained previously, this either enables to position a higher number of adapters in the web 20b of the housing 20 or adapters, in particular hydraulic adapters 8, 34 with greater diameter for efficiency purposes.

[0061] Figure 6a further illustrates a first distance d1 as measured from a free end of the lock fingers 24 to the web 20b or the second set of adapters 34, which first distance d1 is smaller than a second distance d2 illustrated in figure 6b. The second distance d2 as measured from the rear axle 12 to a free end of the second set of adapters 8 may chosen to be smaller than the first distance d1 to ensure that the tilting of the coupling unit 1, upon full retraction of the actuators 22 (c.f. figure 6c), towards the rear axle 12 for embedding the rear axle 12 in the recess 28 does not lead to damages in the second set of adapters 8 of the tool 2.

[0062] Figures 6b and 6c illustrate the coupling sequence in which the actuators 22 are slowly retracted thereby allowing the tilting or pivoting of the coupling unit 1 for embedding of the rear axle 12 in the recess 28. Once the rear axle 12 of the tool 2 is snug embedded in the recess 28, the actuators 22 are extended again and the housing 20 of the actuator device 2 is therewith moving towards the second set of adapters 8 for connection of the first set of adapters 34 with the second set of adapters 8. Upon that extension, the lock fingers 24 are changing the shape of the recess 28 for locking the rear axle 12 firmly in place, as illustrated in figure 6d.

[0063] Referring to figure 6c it is further to be noted that the second set of adapters 8 are arranged in between the lock fingers 24 (c.f. figures 4a to 5b) and that therewith a smooth connection between the adapters 8, 34 takes place.

[0064] It is to be noted that figures 6a to 6d are cross sectional views with parts of the actuator device and the tool partially removed for illustrative purposes.

[0065] Finally, in figure 6d the first set of adapters 34 and the second set of adapters 8 are in an aligned position along the actuator axis a or at least parallel with it.

[0066] The invention has now been explained referring to hydraulic adapters and hydraulic actuators 22. It is however within the scope of the invention to install electric adapters or other devices such as cameras or the like in the web 20a of the housing 20 and/or to use electric actuators instead of hydraulic ones.

[0067] The present invention encompasses various embodiments and their variations that would be apparent to a skilled person. These variations include, but are not limited to, the replacement of features, elements, and/or acts with equivalent ones, the mixing and matching of features, elements, and/or acts from different embodiments, the combination of features, elements, and/or acts from embodiments described herein with those from other technologies, and the omission of certain features, elements, and/or acts from described embodiments.

[0068] While specific embodiments are shown and described in detail in the drawings and the accompanying description, it is understood that these embodiments are provided by way of example and do not limit the scope of the invention. The intention is to cover all modifications, equivalents, and alternatives that fall within the technological realm of the present invention, as defined by the appended claims.

[0069] The headings used throughout this application are for organizational purposes and do not serve to limit the scope of the description. The terms "may," "include," "including," and "includes" are used in a permissive sense, indicating that the invention has the potential to encompass all possible variations, rather than mandating specific requirements. Similarly, the terms "have," "having," and "has" indicate open-ended relationships, meaning that the invention may have additional features beyond those explicitly mentioned.

[0070] The use of ordinal terms such as "first," "second," "third," etc., is for labeling purposes only and does not imply any specific ordering unless explicitly indicated. For example, a "third component mechanically connected to a frame" does not preclude the possibility of a "fourth component mechanically connected to a frame" being connected prior to the third component, unless otherwise specified.

[0071] Components described as "configured to," "arranged to," or "designed to" perform a task or function are understood to have the necessary structure or features to fulfil that task or function during operation. This includes situations where the component is not currently performing the task or function but has the capability to do so. The use of such phrases may also encompass a broad recitation of structure that has the necessary features to perform the task or function, even when the component is not currently in use.

[0072] Throughout the description, specific details are provided to facilitate a thorough understanding of the invention. However, these details are not essential and the invention may be practiced without them. In some instances, well-known elements or components may be omitted or briefly mentioned to avoid obscuring the invention unnecessarily. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive.

[0073] When referring to a component, unless otherwise indicated, the term should be interpreted as including any equivalent component that performs the same function, whether or not it is structurally identical to the one described. The invention should not be limited to the specific embodiments shown and described, but instead should encompass any combination of features disclosed herein, either explicitly or implicitly, as well as any generalization thereof within the realm of the skilled person.

[0074] Various features may be described as present in "some embodiments" or "in another embodiment" or "in still another embodiment" or "in an embodiment." These features are not mandatory and may not be present in all embodiments. The invention may include zero, one, or any combination of two or more of these features. The inventors contemplate embodiments that combine such features, unless otherwise stated or if the features are fundamentally incompatible.

[0075] The appended claims and claims introduced subsequently should be interpreted to include all modifications, permutations, additions, omissions, and subcombinations that are reasonably inferred. The scope of the claims should not be limited by the preferred embodiments or examples described but should be given the broadest interpretation consistent with the description as a whole and the terminology used in the relevant field.

[0076] Specific examples of systems, methods, and apparatus have been provided for illustrative purposes, but the technology disclosed herein can be applied to other systems as well. There are numerous possibilities for alterations, modifications, additions, omissions, and permutations within the practice of this invention.

Claims

1. A coupling unit for exchanging a tool (2), the coupling unit being connectable to a machine and comprising a frame (4) and an actuator device (6), the frame (4) comprising:

- a first side (14) comprising a hook shaped cutout (26) being arranged to receive a front axle (10) of the tool, and

- a second side (16) comprising a recess (28), the recess (28) being arranged to receive a rear axle (12) of the tool, the first side (14) and the second side (16) being arranged opposite one another and the second side (16) further comprising a feed through (30) at the recess (28),

the actuator device (6) comprising:

- a housing (20) having a first set of adapters (34) configured to be connectable to a second set of adapters (8) arranged on the tool (2), the housing (20) further comprising a at least one aperture (38),

- at least one actuator (22) embedded with one side in the at least one aperture (38) and connected to the frame (4) with a free end (44), so that the actuator (22) can extend and retract on a first side of the housing (20) along an actuator axis (a),

- at least one lock finger (24) connected to the housing (20) on a second side opposite the first side and movably embedded in the feed through (30), so that the at least one lock finger (24) moves along the actuator axis (a) upon retraction or extension of the at least one actuator (22), so that the at least one lock finger (24) can change the shape of the recess (28) and thereby lock the rear axle (12) of the tool (2) upon extension of the at least one actuator (22),

characterized in that a height (h) and a width (w) of a cross section of the at least one lock finger (24) as seen in a plane perpendicular to the actuator axis (a) upfill the equation w < h, thus the width (w) is smaller than the height (h) and wherein the height (h) is measured in a direction perpendicular to a plane (p) defined by the frame (4).

2. The coupling unit according to claim 1, wherein a free end of the at least one lock finger (24) is comprising a lock finger recess (46) arranged to change the shape of the recess (28) upon extension of the at least one actuator (22).

3. The coupling unit according to any of claims 1 or 2, wherein a distance (d1) as measured from a free end of the at least one lock finger (24) to the first set of adapters (34) is chosen so that the first set of adapters (34) can move into an aligned position with the second set of adapters (8) without getting in conflict with the second set of adapters (8) upon coupling of the coupling unit to the tool.

4. The coupling unit according to any of the preceding claims, wherein the at least one lock finger (24) has a non-circular cross section.

5. The coupling unit according to any of the preceding claims, wherein the at least one lock finger (24) has a rectangular cross section with rounded edges.

6. The coupling unit according to any of the preceding claims, wherein the at least one lock finger (24) has an oval cross section.

7. The coupling unit according to any of the preceding claims, wherein the frame (4) comprises two feed throughs (30) and wherein the actuator device (6) comprises two actuators (22) and two lock fingers (24), wherein the housing (20) has an H-shape and wherein each leg (20b) of the H-shape comprises an aperture (38) for receiving one of the two actuators (22).

8. The coupling unit according to any of the preceding claims, wherein the adapters (22) of the coupling unit and the adapters of the tool are hydraulic adapters.

9. The coupling unit according to any of the preceding claim, wherein the first set of hydraulic adapters (34) are of the female type.

10. The coupling unit according to any of the preceding claims, wherein the actuator(s) (22) are hydraulic cylinders.

11. The coupling unit according to any of the preceding claims, wherein the actuator(s) (22) are electric actuators.

Drawing