COUPLING DEVICE

Abstract

 A coupling device (1) for a quick coupler (100) prearranged for coupling to an adapter member (200) of a tool for a mechanical arm; the quick coupler (100) has a moving element (108), which is mobile in a direction (D) and is provided with at least one elongated member (110) mobile with reciprocating motion against the thrust of a spring (111) between a retracted position (P1) and an advanced position (P2) for engagement of the adapter member (200); an actuation assembly (112) being provided for switching each elongated member (110) between the retracted position (P1) and the advanced position (P2); the actuation assembly (112) comprising an annular cam (1120) carried by the frame (102), which is rotatable about an axis (103) transverse to the first plate (106); the actuation assembly (112) comprising a cam-follower (1126) transverse to the first plate (106) carried by the moving element (108) inside the cam (1120); a toothed arrest assembly (114) being provided for blocking each elongated member (110) longitudinally and the cam (1120) angularly with respect to the frame (102).

Description

[0001] The present invention relates to a quick coupler. In particular, the present invention refers to a quick coupler that can be used for connecting a tool to a mechanical arm of a heavy-duty machine. In greater detail, the present invention refers to a quick coupler that can be used for connecting a tool to a mechanical arm of a heavy-duty machine and is provided with a rotatable actuation device.

DESCRIPTION OF THE PRIOR ART

[0002] In the sector of heavy-duty machinery provided with mechanical arms it is known to use mechanical interfaces for quick connection and release of tools to/from the free ends of said arms. These interfaces are made up of an adapter member provided with fixed coupling elements, said adapter member, stably coupled to the tool, rendering the latter compatible with a device provided with mechanisms prearranged for selective coupling to the coupling elements of the adapter member. This device is normally referred to as "quick coupler". Consequently, manufacturers of quick couplers habitually also provide appropriately designed adapter members, which, once applied to the portions for engagement of the tools, render the latter interfaceable with their own quick couplers.

[0003] In particular, each adapter member has a boxlike seat, which is laterally delimited by respective parallel sides that are prearranged for coupling with the tool and is longitudinally delimited by a pair of shafts, which are at times built in a substantially identical way but arranged symmetrically with respect to a transverse median plane of the adapter member so that the latter can be used in a reversible way to enable use of the respective tool with two opposite orientations. The quick coupler comprises a frame having a pair of sides that define an engagement portion shaped like a fork prearranged for coupling with any one of the shafts. The quick coupler further comprises at least one elongated member carried centrally and mobile between an operatively neutral retracted position and an advanced position of interference with the bottom portion of the other shaft of the adapter member in such a way as to stabilise connection between the quick coupler and the adapter member, and hence between the mechanical arm and the tool that is to be used.

[0004] Described in the European patent application No. 15156149.5 filed in the name of the present applicant is a quick coupler of a mechanical type, the frame of which carries two elongated members set alongside one another, prearranged for interacting with the respective shaft of the adapter member through a moving element that moves longitudinally against the thrust of a spring for each elongated member. The axial position of the elongated members with respect to the frame of the quick coupler, and hence with respect to the shafts of the adapter member, is controlled by an actuation mechanism provided with an internal cam, rotatably carried by the frame of the quick coupler, and with a roller cam-follower, which internally engages the cam and is associated to the moving element. The longitudinal position of the elongated members with respect to the frame of the quick coupler is hence controlled through the cam, which has a cusp portion that connects a concave portion and a convex portion, and is distinct from the latter by a step-like blocking element, for identifying a parking seat for the cam-follower, operatively corresponding to which is a retracted position of the moving element and a retracted position of the elongated members, which are operatively neutral. As soon as the blocking element of the cam-follower is switched into a position of non-interference with the step-like blocking element, the springs are released from the cam and free to move the moving element into the operatively active advanced position, suited for interfering with the shaft set at the front. Once again according to the European patent application No. 15156149.5, the cam has a plurality of housings provided in the respective concave portion, where each housing is shaped for receiving the roller of the cam-follower in such a way as to counter accidental retraction of the moving element (due to application of excessive stresses on the tool, which have repercussions on the shaft of the adapter member engaged by the elongated members that are associated to the moving element, or consequent upon yielding of at least one of the springs that are coupled to the elongated members) and so as to keep the moving element with the elongated members extracted by a given amount with respect to the frame. In the case in question, the roller is free to turn about its own axis, and hence, in the presence of high speeds of exit of the elongated members, the roller can roll on the surface of at least one housing before being restrained in one of the adjacent housings. The presence of more than one housing has precisely the purpose of increasing safety of the actuation device, which otherwise might not be able to oppose an action that causes retraction of the elongated members, thus causing accidental detachment of the adapter member and hence of the tool. The housings occupy a considerable radial dimension of the concave portion of the inner profile of the cam, so that the degree of adjustment of the position of the cam-follower and of the amount of extraction of the elongated members is modest, with the result that the solution described can be decidedly improved from the standpoint of safety. A possible solution could be to reduce the transverse dimension of the roller cam-follower in order to lengthen the path that the roller should cover to exhaust the energy applied to the elongated members that brings about retraction of the latter, but this solution would reduce the shear strength of the cam-follower and hence risks jeopardising the sturdiness of the quick coupler, rendering use thereof highly risky for operators.

[0005] In the light of what has been described above, the problem of having available a quick coupler of a mechanical type that will be intrinsically safe and in which the degree of extraction of the elongated members can be controlled gradually has so far remained unsolved and represented an interesting challenge for the present applicant.

[0006] Considering the situation described above, it would be desirable to have available a quick coupler provided with an actuation device that, in addition to limiting and possibly overcoming the drawbacks described above typical of the prior art, will define a new standard for these types of devices that can be used for coupling tools to mechanical arms of heavy-duty machinery.

[0007] Considering the situation described above, it would be desirable to have available a quick coupler provided with an actuation device that will enable fine adjustment of the position of the respective elongated members and will make it possible to exert an effective action of control of said position with respect to the frame, to the advantage of operating safety of the quick coupler, in order to improve resistance in regard to release of the elongated members from the corresponding shaft of the adapter member in the presence of vibrations or dynamic or inertial stresses.

SUMMARY OF THE PRESENT INVENTION

[0008] The present invention relates to a quick coupler. In particular, the present invention refers to a quick coupler that can be used for connecting a tool to a mechanical arm of a heavy-duty machine. In greater detail, the present invention refers to a quick coupler that can be used for connecting a tool to a mechanical arm of a heavy-duty machine and is provided with a rotatable actuation device.

[0009] The aim of the present invention is to provide an actuation device for a quick coupler that will enable fine adjustment of the position of the respective elongated members and will make it possible to exert an effective action of control of said position with respect to the corresponding frame, to the advantage of operating safety, in a simple and economically advantageous way.

[0010] According to the present invention, an actuation device for a quick coupler is provided, the main characteristics of which will be described in at least one of the ensuing claims.

[0011] A further aim of the present invention is to provide a quick coupler equipped with an actuation device that will enable fine adjustment of the position of the respective elongated members and will make it possible to exert an effective action of control of said position with respect to the corresponding frame, to the advantage of operating safety, in a simple and economically advantageous which.

[0012] According to the present invention a quick coupler is moreover provided, the main characteristics of which will be described in at least one of the ensuing claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Further characteristics and advantages of the quick coupler and of the respective actuation device according to the present invention will appear more clearly from the ensuing description, with reference to the attached figures, which illustrate at least one non-limiting example of embodiment thereof and in which parts that are identical or equivalent are identified by the same reference numbers. In particular:

• Figure 1 is a schematic perspective view of a quick coupler according to the present invention coupled to an adapter member;
• Figure 2 is an exploded view of the quick coupler of Figure 1;
• Figure 3 is a schematic perspective view of the quick coupler of Figure 1 at an enlarged scale and with parts removed for clarity;
• Figure 4 is a schematic perspective view obtained from Figure 3, with parts removed for clarity;
• Figure 5 is a longitudinal sectioned view of a central portion of the quick coupler of Figure 1 at an enlarged scale and with parts removed for clarity;
• Figure 6 is a top plan view of the quick coupler of Figure 1 in a first operative configuration, with parts removed for clarity;
• Figure 7 is a longitudinal sectioned view of a detail taken from Figure 6 at an enlarged scale and with parts removed for clarity;
• Figure 8 is a top plan view of the quick coupler of Figure 1 in a second operative configuration, with parts removed for clarity;
• Figure 9 is a top plan view of the quick coupler of Figure 1 in a third operative configuration, with parts removed for clarity;
• Figure 10 is a top plan view of the quick coupler of Figure 1 in a fourth operative configuration, with parts removed for clarity; and
• Figure 11 is a longitudinal sectioned view of a detail taken from Figure 10 at an enlarged scale and with parts removed for clarity.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0014] In Figure 1, designated as a whole by 1 is a coupling device 1 for a quick coupler 100 prearranged for coupling to an adapter member 200 of a tool for a mechanical arm of a heavy-duty machine, without this implying any limitation of the scope of the present invention. In particular, the quick coupler 100 has a frame 102, which comprises two first parallel sides 104 (of which just one is visible in Figure 2) connected by a plate 106 and, at the front (on the left in Figure 2), by a first block (known and not illustrated) set between two hook-shaped seats 107 (of which just one is visible in Figure 2). Each seat 107 is provided at the front on a respective side 104 for housing a shaft 206 of the adapter member 200, which will be described more fully hereinafter. The quick coupler 100 has, at the rear (on the right in Figure 2), a block 109 set between the sides 104 and, at the centre, a moving element 108, which is mobile in a longitudinal direction D of the quick coupler 100 itself. The moving element 108 carries at least one elongated member 110, which, together with the moving element 108 itself, can be driven with reciprocating motion against the thrust of a spring 111 between a retracted position P1 (i.e., a position retracted with respect to the frame 102) and an advanced position P2 (once again with respect to the frame 102) in the direction D of engagement of the shaft 206. Each elongated member 110 is axially delimited by a wedge-shaped free end 1100 on the side opposite to that of the moving element 108, and the block 109 has a guide hole 1090 for each elongated member 110. The position P1 is visible only in Figure 6, whereas the position P2 is visible in Figures 8, 10, and 11, and will be discussed more fully hereinafter.

[0015] The quick coupler 100 further comprises an actuation assembly 112 prearranged for switching each elongated member 110 between the retracted position P1 and the advanced position P2. The actuation assembly 112 comprises an annular cam 1120, which is carried by the frame 102 in such a way that it is able to rotate about a fulcrum axis 103 by means of a pivot 1030, which in turn is set transverse to the plate 106. The cam 1120 has a slot 1122 shaped like a cashew nut in top plan view. In particular, with reference to Figure 6, the cam 1120 has a concave portion 1121 and a convex portion 1123 facing one another and connected by a slightly curved stretch 1125. The slot 1122 has a radiusing portion 1127 between the concave portion 1121 and the convex portion 1123, on the side opposite to the stretch 1125, which terminates with a step 1129 on the side of the convex portion 1123, the function of which will be explained more fully hereinafter. On the outside of the stretch 1125, the cam 1120 is delimited by an active stretch 11201. Moreover, the actuation assembly 112 has a spring 11202, which connects the frame 102 on the left of the axis 103 with the radiusing portion 1127 to counter clockwise rotation of the cam 1120.

[0016] With particular reference to Figure 3, the slot 1122 is delimited by an annular surface 1124 parallel to the axis 103, and the actuation assembly 112 comprises a cam-follower 1126 carried by the moving element 108 inside the slot 1122. The cam-follower 1126 is provided with a roller 11262, with its rolling surface facing the surface 1124. The coupling device 1 comprises an arrest gear pair 114, the function of which is to block any accidental longitudinal recession of the ensemble comprising the moving element 108 and the elongated members 110 (from the advanced position P2 to the retracted position P1), and rotation of the cam 1120, following upon an anomalous action exerted on the elongated members 110 that, in use, tends to cause displacement of said members from the position P2 to the position P1.

[0017] With reference to Figure 3 and in particular to Figure 4, the arrest gear pair 114 comprises a C-shaped member 1142, which is fixedly coupled to the concave portion 1123 of the cam 1120, hence on the same side as the moving element 108. The C-shaped member 1142 is splined on the pivot 1030 in a position underlying the roller 11262, and has a toothed portion 11420, provided with a plurality of teeth 114200 (Figure 4).

[0018] With particular reference to Figure 5, the cam-follower 1126 comprises the pin 11260, carrying the coaxial roller 11262, with axis parallel to the fulcrum axis 103, which faces the surface 1124. The arrest gear pair 114 further comprises at least one toothed sector 1140, which projects from a lowered cylindrical member 1142, the longitudinal extension of which approximates the longitudinal extension of the roller 11262, and is carried by the pin 11260 in an angularly fixed way in a position facing the toothed portion 11420 and underneath said roller 11262. The toothed portion 11420 has an angular extension of at least 10° so as to present, in use, at least one respective tooth 114200 positioned in such a way as to enable selective meshing with at least one tooth 11400 when the cam 1120 is in any one of the angular positions comprised between the position P1 and the position P2. The sector 1140 has a plurality of teeth 11400, each of which develops substantially in the direction D and is shaped and proportioned like the teeth 114200. In particular, each tooth 11400 is rigidly carried by the pin 11260 so that it partially overlaps the roller 11262 in the longitudinal direction.

[0019] The coupling device 1 comprises a feeler member 40, which is carried by the block 109 in a position eccentric with respect to the axis 103. It should be pointed out that said feeler member 40 has a head 42 visible in Figures 6, 7, 9, and 10, the function of which is to interact like a cam-follower with the stretch 11201 of the outer profile of the cam 1120. Consequently, the feeler member 40 is carried by the block 109 in an axially free way and is constrained so as to assume an axial position uniquely determined by the angular position of the cam 1120.

[0020] With particular reference to Figure 2, the adapter member 200 has a housing 202 for the quick coupler 100, where the housing 202 is delimited by two second sides 204 connected by a plate 208 and by a pair of shafts 206. Said shafts 206 are carried between the two sides 204 above the elongated members 110 and extend, in use, transverse to the direction D so that they can be engaged by each elongated member 110 underneath. The shafts 206 both have an inclined face 206' facing upwards in a symmetrical way to render the adapter member reversible. On the other hand, the block 109 of the quick coupler 100 has a face 1092 inclined downwards prearranged for interacting with any one of said faces 206' for gripping like a vice a corresponding shaft 206, together with the free ends 1100 of the elongated members 110.

[0021] It may be pointed out that the coupling device 1 has been designed in such a way that it can be actuated mechanically, without this implying any limitation of the scope of the present invention. In particular, according to Figures 1 and 2, the actuation assembly 112 comprises a crank 112' splined on the pivot 1030 prearranged for turning the pivot 1030 about the axis 103. On the other hand, rotation of said pivot 1030 could be governed by an electric motor (known and not illustrated) carried by the quick coupler above a lid 106', with its own drive shaft mechanically coupled to the head of the pivot 1030 in a way known and not illustrated.

[0022] Use of the coupling device 1 is easy to understand from what has been described above, even though the following description, with reference to Figures 6-11, may prove useful. In particular, in Figure 6 the coupling device 1 is set with the moving element 108, and hence with the elongated members 110, in a position P1. This position is longitudinally retracted with respect to the frame 102 and is hence operatively neutral, given that the ends 1100 of the two elongated members 110 are detached from the shaft 206 facing them. It should be pointed out that the function of the spring 11202 is to limit the movement of retraction of the elongated members 110, so as to set an arc of teeth 114200 of a given angular extension facing the teeth 11400 of the sector 1140 in such a way that, in the case of retraction of the moving element 109/elongated members 110, the probability of stable meshing between the teeth 114200 and the teeth 11400 will be maximum. It should be pointed out that, in the absence of the spring 11202, in the case where the elongated members 110 were to undergo a displacement/recession from the position of interference with the shaft 206 of the adapter member 200, the cam 1120 would be free to turn about its own axis 103. The consequence would be that the position of blocking of the elongated members 110 in a gripping position would not be guaranteed in the presence of vibrations or dynamic or inertial stresses acting on the shaft 206 engaged by the elongated members 110 or as a result of failure of at least one of the springs 111. Consequently, in this position, the cam 1120 houses the roller 11262 in its own radiusing portion 1127, to the left of the step 1129, and the feeler member 40, the head 42 of which interacts with the stretch 11201, is pushed downwards by said stretch and kept in its own position further extracted from the block 109. It should be noted that the position of the roller 11262 is meta-stable but will remain unchanged until the feeler member 40 is pushed by the shaft 206 towards the seats 107 and hence imposes a counter clockwise rotation on the cam 1120 with a force that overcomes the resistance of the springs 111. This rotation has the effect of rotating the cam 1120 and of bringing the step 1129 to the left of the axis 103. From this moment onwards, the springs 111 will be released from the cam 1120 and will control displacement of the block 108, and of the elongated members 111, on the side opposite to the seats 107 until the configuration of Figure 8 is reached, where the roller 11262 is in contact with the convex portion 1123 on the side of the stretch 1125. This configuration may evolve freely into the configuration of Figure 9 in the presence of external actions exerted on the elongated members 110 that tend to bring the respective ends 1100 back into the block 109. On the other hand, the combined presence of the toothed portion 11420, which is associated to the concave portion 1121 of the cam 1120, and of the teeth 11400 of the sector 1140, which is associated to the pin 11260, will prevent an excessive detachment D of the face 1092 of the block 109 (Figure 11) from the corresponding shaft 206, as well as consequent entry of the respective ends 1100 back into the block 109, and, in operating conditions in which said ends 1100 interact with the bottom portion of the corresponding shaft 206, detachment of the quick coupler 100 from the adapter member 200.

[0023] It may readily be understood that release of the coupling between at least one tooth 11400 of the sector 140 and at least one tooth 114200 of the toothed portion 11420 (Figure 10) is possible only in the condition of longitudinal recession of the moving element 108 from the seats 107 for a length greater than the size of the teeth 114200 of the toothed portion and 11400 of the sector 1140.

[0024] Finally, it is clear that modifications and variations may be made to the coupling device 1 and to the quick coupler 100 that incorporates it that are described and illustrated herein, without thereby departing from the sphere of protection of the present invention.

[0025] On the basis of what has been described above, it may readily be understood that the coupling device 1 and the quick coupler 100 that incorporates it enable the elongated members 110 to be kept in contact with the respective shaft 206 even in the presence of longitudinal displacements imposed on said members that have an extension less than the radial extension of the teeth 11400 of the sector 1140, thus keeping the adapter 200 coupled to the quick coupler 100 to the advantage of operating safety of the quick coupler 100 itself.

Claims

1. A coupling device (1) for a quick coupler (100) prearranged for coupling to an adapter member (200) of a tool for a mechanical arm; said quick coupler (100) having: a frame (102) comprising two first parallel sides (104) connected by a first plate (106); and a moving element (108) provided with at least one member (110) elongated in a direction (D) and mobile with reciprocating motion against the thrust of a spring (111) between a retracted position (P1) and an advanced position (P2) of engagement of said adapter member (200); actuation means (112) being provided for switching each said elongated member (110) between said retracted position (P1) and said advanced position (P2); said actuation means (112) comprising an annular cam (1120) carried by said frame (102), which is able to rotate about a fulcrum axis (103) transverse to said first plate (106); said actuation means (112) comprising a cam-follower (1126) transverse to said first plate (106) carried by said moving element (108) inside said cam (1120); said device being characterized in that it comprises toothed arrest means (114) for blocking, with respect to said frame (102), each said elongated member (110) longitudinally and said cam (1120) angularly.

2. The device according to Claim 1, characterized in that said arrest means (114) comprise a C-shaped member (1142) provided with a toothed portion (11420), fixedly coupled to said cam (1120) on the same side as said moving element (108) in a position underlying said roller (11262); said cam-follower (1126) comprising a second pin (11260), carrying a coaxial roller (11262), with axis parallel to said fulcrum axis (103), that faces said cam (1120); said arrest means (114) comprising at least one toothed element (1140) (11400), which is carried by said pin (11260), faces said toothed portion (11420), and develops substantially in said direction (D).

3. The device according to Claim 2, characterized in that said toothed portion (11420) extends through at least 10° for selective meshing with each said element (1140).

4. The device according to Claim 3, characterized in that each said element (1140) extends radially from a cylindrical member (1142) carried in an angularly fixed way by said second pin (11260) underneath said roller (11262).

5. The device according to Claim 4, characterized in that each said element (1140) (11400) is rigidly carried by said second pin (11260) so that it partially overlaps said roller (11262) in a longitudinal direction.

6. The device according to any one of the preceding claims, characterized in that said adapter member (200) has a housing (202) for said quick coupler (100), where said housing (202) is delimited by two second sides (204), which are connected by a second plate (204), and by a pair of shafts (206), which are arranged between the two said sides (202) above said elongated members (110) and extend, in use, transverse to said given direction (D) so that they can be engaged by each said elongated member (110).

7. The device according to any one of Claims 2-6, characterized in that said actuation means (112) comprise a mechanical element (112') prearranged for turning said cam (1120) about said axis (103).

8. The device according to Claim 7, characterized in that said mechanical element (112') comprises a crank (112') splined on a pivot (1030) sharing said axis (103).

9. A quick coupler (100) prearranged for coupling to an adapter member (200) of a tool for a mechanical arm (M), characterized in that it comprises a coupling device (1) as described in any one of Claims 1-8.

Drawing