QUICK COUPLING ASSEMBLY

Abstract: A method to connect and disconnect a push-pull coupling in a push-pull assembly and a push-pull assembly for mounting a tool on a work machine, whereby the tool comprises several attachment bushings (8) for fitting of fulcrum pins, by means of which the tool is attached to the work machine, into the same. The fulcrum pins are fixed to the work machine and the fulcrum pin of the attachment line is formed of two pins (20, 22) opposite each other and horizontally movable in opposite directions.

Description: Quick coupling assembly. This invention relates to a push-pull assembly and a method for automatic connection of the push-pull coupling of the assembly as presented in the introduction chapter of patent claim 1 . Previously known are pull-push assemblies for attaching scoops, bulldozer blades or other tools on work machines. Generally known is a connecting piece adapted to the work machine and furnished with hooks and a locking device. By means of the hooks the tool can be picked up, for instance, from the ground on fulcrum pins in the work machine, which match with the hooks in the tool and round which the hooks are wound. The connecting piece has also a locking device to secure the tool at least from anothere spot to the con¬ necting piece. The attachment of a tool is carried out from the work machine cabin. On using a connecting piece a disadvantage is the fact that the tool must be furnished with counter-pieces matching with the hooks. The connecting piece means increased weight, especially at the head of an excavator boom, and especially a decrease of the breaking strength of the excavator scoop while lengthening the scoop torque arm. By means of a push-pull assembly according to this invention, these disadvantages are eliminated and the invention is char¬ acterized in what is presented in the enclosed patent claims 1 and 6. The advantages of this invention are that the tools can be quite normal scoops, bulldozer blades or percussion devices with usual mounting holes for fulcrum pins. No separate conneting piece is needed that would increase weight and lengthen the boom arm. Further, as by other push-pull means, mountings and tool replace¬ ments can be carried out from the work machine cabin. This push- pull assembly allows automatic coupling of pressure connectors and electric connectors. In the following the invention is disclosed with reference to the enclosed drawing, where F ig. 1 is a side view of an excavator boom head and a scoop. Fig. 2 is the inverted image of the details in figure 1. Fig. 3 is a sectional view of a fulcrum pin assembly. Fig. 4 is a sectional view of another embodiment. Fig. 5 is automatic connection of a pressure connector. Fig. 6 is a sectional view of a third embodiment of the invention. Figure 1 shows the head of an excavator 2 boom to which scoop 9 is attached. Scoop 9 has two attachment lines 17 to which bushings 8 are applied. In the head of boom 2 there is an immobile mounting hole 5 matching with the pins of the assembly of this invention. Further, at the head of boom 2 there is a mobile mounting hole 4, into which the inventional assembly also fits. The mobile joint 4 is in one end of arm 3 and effected by cylinder 1. In addition, the boom 2 has a steering mechanism comprising an arm 7 and hole 6 to control the cylinder 1 head and allowing the scoop 3 greater clearance by means of arm 3. Figure 2 shows a boom 2 head in a position from where it is lower¬ ed to the attachment line 17 in scoop 9 in order to fit the pins 10 of mounting hole 5 into bushings 8. In the near vicinity of the of bushings 8 there can be control surfaces to facilitate the alignment of boom head and mounting hole 5 with attachment line 17. When the boom head has reached its proper position, the ful¬ crum pins 10 are pushed out from the mounting hole 5, whereat they are guided into bushings 8 and the tool 9 is locked in the boom head. Then the mounting hole 4 is secured in the same manner to the other scoop bushings 8 in pushing out the corresponding ful¬ crum pins 10 into the open ends of bushings 8 by means of com¬ pressed air or hydraulic pressure. Disconnection of tool is easily carried out simply by pulling in the fulcrum pins 10 by means of compressed air or hydraulic pressure. Figure 3 shows a simple example of the push-pull assembly, where fulcrum pins 10 can be moved in and out. Fulcrum pins 10 are bush¬ ings moving on a shaft pin 13 supporting them from the inside. The immobility of shaft pin 13 is secured by fixing it by means of a support 14 to an outer bushing 11 that functions as a frame. Support 14 is a ring almost enveloping shaft pin 13 and preventing shaft pin 13 from bending in situations of stress. Pressure push¬ ing out fulcrum pins 10 is conveyed along channel" 15 to the ring space that is formed between the fulcrum pins 10. Pressure pulling in the fulcrum pins is conveyed along channel 16 to the smaller ring spaces, where a force is generated by pressure against the fulcrum pin 10 collars and pushing them against each other. Separ¬ ate bushings 12, which also have ring packings, are very important with respect to the composition of the assembly. The assembly is attached from its outer bushing 11 to boom head 2 and likewise to the arm 3 end. On using traditional tools, scoops for example, two assemblies are needed. Figure 4 shows an advanced pin, which is a part of this push-pull assembly and operated by pressure medium, the advantage of which is, referred to the figure 3 version, that the pushed-out pins 20, 22 need not to be tightened to frame 11 or to guide bushings 21. In fact, the pressure of the medium does not have any impact on the gliding surface between them and no leakage occurs if the sur¬ faces are damaged, which can be the case in the figure l version. The pushing-out force of pins 20, 21 is conveyed through the inlet 28 into tube 30 and to the rear of piston 23. Piston rod 24 pushes out pin 20 against the conical stopper surface between bushing 21 and ring 19. Due to pressure, both pins travel out and it is ad¬ vantageous to leave the pressure active, whereat pins 20, 21 are supported by the conical surfaces of bushings 21. The pressure feeding unit connected to pin 20 and support 27 of piston rod 24 move along with pin 20. In the middle of frame 11 there is a stop ring, due to which both pulled-in pins end up on both sides of the ring. The pulling-in of pins is carried out by conveying pressure through inlet 29 to cylinder space 25 in pin 22, whereat the pins travel to a position as per figure 4. Figure 5 shows an automatic pressure tube coupling that is added to the embodiment presented in figure 4, where the sideward motion of pin couples the hydraulic connection 37, 38 as the pins travel out. The connector 37 is arranged to move along with pin 22 and is fixed by means of a special support frame 33 to pin 22. The motion of pins 20, 22 is guided by pressure medium flowing through tubes 34,35. The connector 38 is fixed to the work machine by means of support 32. To make the connector 37 hit connector 38, the assemby can be furnished with special guides to guide the connectors into interconnection. A necessary number, i.e. several connector pairs, can be coupled simultaneously. Pins 20 and 22 are forced outward by means of continuos pressure, whereat the coupling of connectors 37,38 remains connected. In addition to the continuos pressure effect, locking of couplings 38,37 can also be made otherwise, a.o. by mechanical means. Figure 6 shows a version, where movable pins 46 cannot rotate. Their heads are furnished with bushings 39 that rotate, if needed, round pins 46. Buhshings 39 can be easily replaced, for instance, if worn out. Rotation of bushings 39 is prevented by a stopper 44 fitted between bushings 21 in the bottom part of the frame. At this stopper the pins 46 have no conical extension. Instead, these conical extensions are on side portions of the pins that take sup¬ port from the matching bevel face of bushings 21 by the said por¬ tion of their sides. Also the upper edge of the pins is without an extension so that in the pulled-in position of the pins it stays in the slot between pins 46. In the stopper end there are notches for the pressure feeding unit 45. The stopper has also a bracket 47 to control the position of the pins when they are pulled-in. The pins are pulled in till their rear edges hit the bracket. Piston rod 40 comprises pressure channels 42 for pushing out pins and its travel can also be utilized to couple one or several pres¬ sure connectors. Lubrication to the glide face of pins 46 can be conveyed over channels 49.

Claims: PATENT CLAIMS 1 . A push-pull assembly for mounting a tool (9) on a work machine, whereby the tool (9) comprises several pairs of attachment bush¬ ings (8) for fitting of fulcrum pins, by means of which the tool is attached to the work machine, into the same and each pair of bushings corresponding to a pair of fulcrum pins, which is fixed to the work machine and formed of two horisontally movable pins (20,22), (39) arranged opposite each other, characterized in that at least one of the pins (22), (39) in the fulcrum pin pair is a double-acting with pressure medium operated cylinder (22);(39) with an in-built piston (23) moving with regard to the cylinder. 2. An assembly according to patent claim 1 characterized in that one pin (20) of the fulcrum pin pair is fastened to the piston rod (24) that is moved by piston (23) inside the other pin (22). 3. An assembly according to patent claims 1 and 2 characterized in that in the ' rear part of the fulcrum pin (20,22,46) there is a conical expansion or an expansion part (19) with a counter-face in frame (11) restricting the travel of the pin to the outward. 4. An assembly according to any of the patent claims 1 and 3 characterized in that the assembly includes a steering device (44) that prevents rotation of fulcrum pins (46) during axial movement. 5. An assembly according to patent claim 4 characterized in that there are replaceable bushings (39) in the fulcrum pin ends. 6. A method for automatic connection of coupling (37,38) between pressure tubes and electric cables in a push-and pull assembly of a tool (8) as per patent claim 1 characterized in that one part (38) of the coupling is connected to the tool which is to be mounted and the other part (37) is connected to pin (22) or piston rod (40) in the said assembly, either directly or by means of an auxiliary frame (33), (45), and that the coupling is arranged to switch on and off by means of the longitudinal travel of pin (22) or piston rod (40). 7. A method according to patent claim 6 characterized in that the pins of the push-pull assembly are forced to the outward by means of pressure medium when, for instance, the tool is coupled by the pins to work machine.

Inventors: RAUNISTO YRJOE, RAUNISTO, YRJOE
Applicants: RAUNISTO AIRI, RAUNISTO YRJOE, RAUNISTO, AIRI, RAUNISTO, YRJOE
Application year: 1995
Main classification: E02F3
IPC codes: E02F3