DESCRIPTION

Technical Field

The present invention generally relates to a mechanism for quickly and securely connecting an attachment to a construction machine.

Background Prior Art

Attachments for construction machines, such as excavators, back hoes, and earth drills, are typically interchangeable. These machines are used extensively in civil engineering and construction work. An attachment is typically secured at a head of a machine arm. The arm and attachment are controlled by hydraulic power to dig or make grooves in the ground.

Construction machines can be used for many purposes by changing attachments. For example, by securing different width buckets to the machine, it can be used to dig various types of holes in the ground. Similarly, a grip can be attached for loading or unloading work, or a breaker can be attached for destroying a building. Unfortunately, changing attachments has historically taken significant time and manpower. Pins connecting the attachment to the machine arm must be pulled, and the attachment removed by a ground crew. Then, another heavy attachment must be aligned with the head of the arm and secured in place by reinserting the pins. This procedure takes several workers nearly one half hour to complete and is a very inefficient use of the site work force.

Hooks have also historically been used to secure attachments to the head of the machine arm. The problem with this type of securement is that only one pair of hooks is provided, and this type of securement is too weak to hold and firmly secure the attachment to the head of the machine arm.

The present invention is provided to solve these and other problems.

Summary of the Invention

The present invention provides a mechanism for firmly connecting an attachment to a construction machine. Generally, the mechanism comprises two pair of opposite facing hooks for engaging the pins of the attachment. Preferably, two stationary, downwardly facing hooks project from a base, and two movable, upwardly facing hooks project from a joining member. A

hydraulic cylinder moves the hooks together to catch and surround the attachment pins. When the attachment has a pair of pins, one stationary and one movable hook surround each pin. When the attachment has three attachment pins, one stationary and one movable hook surround the central attachment pin. A second stationary and a second movable hook engage the inside surfaces of the outer attachment pins.

One advantage of the present invention is that a machine operator can single handedly change the attachment on the head of the machine arm. This greatly reduces the number of workers needed for the operation and increases the overall efficiency of the work force.

Another advantage of the present invention is that it is unnecessary to remove and install the pins that connect the attachment and the machine arm. This reduces the time needed to change attachments and provides for more efficient use of the construction machine.

A further advantage of the present invention is that workers need not lift the heavy attachments or come near them when the machine is moving. No pins need be removed and reinserted, and workers do not have to pick up and align the heavy attachments with the head of the machine arm. This provides a safer working environment by reducing the risk of injury to workers.

A still further advantage of the present invention is that it provides a mechanism with two pair of hooks which greatly increases the holding power of the mechanism. Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawing.

Brief Description of Drawings

Figure 1 is a diagonal view of an excavator equipped with the invention.

Figure 2 is a perspective view of the invention mounted on the head of a machine arm.

Figure 3 is a sectional view of the mechanism and an attachment base.

Figure 4 is a sectional view showing the mechanisms in the open and closed positions. Figure 5 is a side view showing the mechanism prior to being connected to an attachment.

Figure 6 is a side view showing a completed connection with the machine arm raised.

Figure 7 is a perspective view of a second embodiment of the mechanism installed at the head of a machine arm.

Figure 8 is a sectional view of a second embodiment of the mechanism and an attachment base.

Figure 9 is a sectional view of a second embodiment of the mechanism showing it in the open and closed positions.

Detailed Description

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail, preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiments illustrated.

The present invention is a mechanism for remotely connecting an attachment to an excavation or construction machine. As shown in Figure 1, a typical construction machine has a main body 1 consisting of an engine and two crawlers 2 by which the main body is able to move forward and reverse, and left and right. A boom 3 is pivotally attached to the front of the main body 1. Hydraulic boom lift cylinders 4 are typically provided for raising and lowering boom 3. An arm 5 is connected to boom 3 and an arm cylinder 6 is provided for raising and lowering the arm. A bucket cylinder 7 is located near the middle of arm 5. A cylinder rod 8 is located at one end of bucket cylinder

7. A first pair of links 9 are joined on both sides of rod 8 and connected near the head of arm 5. A second pair of links 10 are connected on both sides of an end of cylinder rod 8. Links 9 and 10 are pivotally connected at one end of cylinder rod 8. Lower ends of links 9 are preferably pivotally connected to the head of boom 5 with a pin 24. Mechanism 11 is mounted between a head of links 10 and the head of arm 5. Arm 5, links 9 and 10, and mechanism 11 form a link mechanism which looks somewhat like a warped square.

Mechanism 11 generally comprises two pair of opposite facing hooks. In one embodiment of the invention, the mechanism is intended for use with an attachment having a pair of attachment pins. Attachments, such as the bucket 17 shown in Figure ι, are typically provided with an attachment base 18. A pair of parallel attachment pins 19 and 20 can be installed horizontally on an upper and a lower side of bucket base 18. Pins 19 and 20 are preferably installed in the existing attachment holes.

In this embodiment, a pair of upper stationary hooks 12 project from upper right and left sides of mechanism 11. A pair of lower stationary hooks 14 project from lower right and left sides of mechanism 11. Upper movable hook 13 is preferably located between upper stationary hooks 12 and lower stationary hooks 14. Lower movable hook 15 is preferably located below lower stationary hooks 14. Stationary hooks 12 and 14 are preferably downwardly facing. Movable hooks 13 and 15 are preferably upwardly facing. Mechanism 11 is also provided with a means for moving movable hooks 13 and 15, such as a hydraulic cylinder 16. Hydraulic cylinder 16 moves hooks 13 and 15 so that attachment pins 19 and 20 are captured and surrounded by hooks 12-15. Mechanism 11 preferably has a base 25 constructed of a "U" shaped piece of steel. Ends of mechanism base 25 cover links 10 and the head of machine arm 5. A top side of base 25 is pivotally connected to links 10 by pin 26. Similarly, a bottom side of base 25 is pivotally

connected to the head of arm 5 by pin 27. An opening 28 is located on a front flat surface of mechanism base 25. Opening 28 is preferably rectangular in shape.

Upper stationary hooks 12 are preferably "L" shaped and project from right and left sides of an upper end of opening 28. Lower stationary hooks 14 are also preferably "L* ¹ shaped and project from a bottom side of base 25. Hooks 12 and 14 preferably form downwardly facing concave surfaces 29 and 33 respectively. As shown in Figure 3, a joining member 30 is preferably used to connect movable hooks 13 and 15. Joining member 30 is preferably rectangular in shape and adjacent to nearly the same length as base 25. Joining member 30 is shown to move linearly with respect to base 25, although it should be understood that the joining member could rotate or move in some other manner.

Movable hooks 13 and 15 project from joining member 30, and preferably combine to form one integral piece. Upper movable hook 13 projects through opening 28. Hooks 13 and 15 form upwardly facing concave surfaces 31 and 32 respectively. Concave surfaces 31 and 32 face opposite concave surfaces 29 and 33.

A support plate 34 is preferably attached to lower stationary hooks 14. One end of hydraulic cylinder 16 is mounted to plated 34. Cylinder 16 has a cylinder rod 35 that is preferably connected to upper movable hook 13.

The distance between a deepest point of concave surfaces 29 and 33 of stationary hooks 12 and 14 is the same as the distance between bucket pins 19 and 20. Similarly, the distance between a deepest point of concave surfaces 31 and 32 of movable hooks 13 and 15 is the same as the distance between pins 19 and 20.

Figure 5 shows connective mechanism 11 in its open position, prior to attachment to bucket 17. To open the mechanism, cylinder rod 35 is contracted by hydraulic cylinder 16 so that movable hooks 13 and 15 are lowered. This separates stationary hooks 12 and 14 from movable hooks 13 and 15. The spaces formed between the two pair

of hooks, (12 and 13) and (14 and 15) respectively, are capable of receiving pins 19 and 20.

Once in its open position, mechanism 11 is moved toward bucket 17. This can be done by controlling hydraulic cylinders 4 and 6 which move boom 3 and arm 5 respectively. Pin 19 goes between upper stationary hook 12 and upper moveable hook 13, and moves into a preferably elliptical space formed by these hooks. Pin 20 goes between lower stationary hook 14 and lower movable hook 15, and moves into another preferably elliptical space formed by these hooks. A top surface of pins 19 and 20 preferably settle into and contact concave surfaces 29 and 33 respectively, as shown in Figure 4.

Once aligned in the above manner, cylinder rod 35 is extended. This causes movable hooks 13 and 15 to move upwardly. Upper movable hook 13 comes in contact with a bottom of pin 19. At the same time, lower movable hook 15 comes in contact with a bottom of pin 20. Pin 19 is captured between upper stationary hook 12 and upper movable hook 13. Pin 20 is captured between lower stationary hook 14 and lower movable hook 15. This closed position is shown in Figure A by dotted lines. Bucket 17 is now firmly connected to arm 5 and can be raised as shown in Figure 6. To disconnect bucket 17, it should first be lowered onto the ground. Cylinder rod 35 is then retracted. Movable hooks 13 and 15 move down and no longer surround bucket pins 19 and 20. Arm 5 can now be disengaged from bucket 17 by use of hydraulic cylinders 4 and 6. By following the above steps, the head of machine arm 5 can be remotely changed from one attachment to another by a machine operator.

Figures 7, 8 and 9 show a second embodiment of the invention. In this embodiment mechanism 11 is provided with hooks 43, 45, 52 and 54 for engaging an attachment having three parallel pins 57, 58 and 59. Attachment pins 57, 58, and 59 are again preferably parallel and horizontal.

In this embodiment, mechanism 11 has a base 41 preferably constructed of a • ^• U" shaped steel plate. Mechanism base 41 is joined to the head of second links 10 and the head of arm 5 as shown in Figure 7. Base 41 has a flat front surface and two sides that cover the heads of links 10 and arm 5. The top side of base 41 and the head of links 10 are pivotally joined by a pin 26. A bottom of base 41 and the head of arm 5 are also pivotally joined by a pin 27. The flat surface of mechanism base 41 is provided with an opening 42 that is preferably rectangular in shape. Rectangular opening 42 preferably spans from a top to a middle of base 41. A pair of upper stationary hooks 43 are preferably located at the middle of base 41, one hook on each side of opening 42. A pair of lower stationary hooks 45 are preferably located on both sides of a bottom of base 41. Hooks 43 and 45 preferably form downward facing concave surfaces 44 and 46 respectively. As shown in Figure 8, an "L" shaped bracket 47 is located inside the bottom of mechanism base 41. Hydraulic cylinder 48 is positioned on bracket 47 and moves a cylinder rod 49 in an upward direction. Another bracket 50 is located at a top of cylinder rod 49 and is connected to a joining member 51. An upper movable hook 52 is preferably attached to a top of interlock 51 and projects in a right angle through hole 42. A lower movable hook 54 is preferably attached to a bottom of joining member 51 and also projects in a right angle through hole 42. Hooks 52 and 54 preferably form upwardly facing concave surfaces 53 and 55 respectively. Upper movable hook 52 is located above upper stationary hook 43. Lower movable hook 54 is located between upper stationary hook 43 and lower stationary hook 45.

As shown in Figures 8 and 9, hooks 43, 45, 52 and 54 are positioned relative to attachment pins 57-59. Hooks 43, 45, 52 and 54 form two sets of opposite facing hooks. A first set is formed by hooks 43 and 54. A second set is formed by hooks 45 and 52. The distance between the centers of attachment pins 58 and 59 should be the same

as the distance between the deepest parts of stationary hooks 43 and 45. The distance between the center of pins 57 and 58 should be the same as the distance between the deepest parts of movable hook 52 and 54. When cylinder rod 49 is retracted by hydraulic cylinder 48, upper and lower movable hooks 52 and 54 simultaneously move downward as shown in Figure 8. In this open position, the distance between an edge of upper movable hook 52 and an edge of lower stationary hooks 45 is shorter than the distance between a highest point of bucket pin 57 and a lowest point of bucket pin 59. The distance between edges of upper stationary hook 43 and lower movable hook 54 is greater than the diameter of bucket pin 58. Mechanism 11 can now be moved to engage attachment 17 as in Figure 9. Upper movable hook 52 and upper stationary hook 43 are inserted into a space between pins 57 and 58. Lower movable hook 54 and lower stationary hook 45 are inserted into a space between pins 58 and 59. Bucket pin 58 is inserted into a preferably elliptical space formed by upper stationary hook 43 and lower movable hook 54.

Once hooks 43, 45, 52 and 54 have been inserted between attachment pins 57-59, mechanism base 41 is preferably moved so that stationary hooks 43 and 45 touch the top of pins 58 and 59 respectively, as shown in Figure 9. While in this position, cylinder rod 49 is extended by applying hydraulic pressure to the cylinder 48. Hooks 52 and 54 move upwardly as shown by arrow B. Upper movable hook 52 touches a lower side of pin 57 and lower movable hook 54 touches a lower side of pin 58.

Mechanism 11 is now in its closed position. Attachment pin 58 is captured and surrounded by hooks 43 and 54, and pins 57 and 59 are engaged and partially surrounded by hooks 52 and 45. In this way, pins 57-59 are firmly held by hooks 43, 45, 52 and 54.

Although Figures 7, 8 and 9, show the bottom of attachment pin 57 being engaged by upper movable hook 52 and the top of attachment pin 59 being engaged by lower

stationary hook 45, it should be understood that hooks 43, 45, 52 and 54 could be positioned in other ways. For example, upper movable hook 52 could be adapted to engage the top of attachment pin 57, and lower stationary hook 45 could be adapted to engage the bottom of pin 59.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.