The present disclosure relates generally to a counterweight attachment and removal system, and more particularly to a counterweight attachment and removal system including a rotate cylinder for pivoting a lift pin and a slide cylinder for axially moving the lift pin.
Heavy duty machines, such as hydraulic excavators, loaders, and the like, frequently have a counterweight attached to the back end of the machine to counterbalance the weight of an implement or work tool mounted on the front end of the machine. The counterweight may vary from a few hundred pounds on small machines to several tons on larger machines, and enables the machines to lift heavier loads and increases the stability of the machine during operation. The weight of the counterweight adds significantly to the total weight of the machine and, as such, may prove problematic when transporting the machine. For example, it may be necessary to remove the counterweight from the machine and transport the counterweight separately from the machine to comply with regulations regarding vehicle loads.
U.S. Pat. No. 7,669,898 to Hamaguchi et al. teaches an apparatus for detaching and attaching a counterweight that includes two links and three cylinders. Specifically, a proximal end of a first link is pivotally supported by a machine frame. A distal end of the first link supports a proximal end of a second link and distal ends of two cylinders. Proximal ends of the two cylinders are attached to the machine frame. A third cylinder has a proximal end attached to the first link and a second end attached to a distal end of the second link. A counterweight moves between detached and attached positions by pivoting the first link using the first and second cylinders. The counterweight may be raised and lowered by pivoting the second link using the third cylinder. The Hamaguchi et al. solution may be overly complex by the need for three separate hydraulic cylinders and associated moving parts.
The present disclosure is directed toward one or more of the problems set forth above.
In one aspect, a counterweight attachment and removal system includes a machine mounting bracket and a link having two spaced apart arms. A proximal end of the link is pivotably coupled with the machine mounting bracket. A rotate cylinder has a proximal end pivotably coupled with the machine mounting bracket and a distal end pivotably coupled with a distal end of the link. A slide cylinder has a proximal end pivotably coupled with the link and a distal end pivotably coupled with a lift pin. The lift pin is positioned through slots defined by the two spaced apart arms. The counterweight attachment and removal system includes a first configuration in which the link is pivoted away from the machine mounting bracket, the rotate cylinder is refracted, the slide cylinder is extended, and the lift pin is positioned through distal portions of the slots. According to a second configuration, the link is pivoted toward the machine mounting bracket, the rotate cylinder is extended, the slide cylinder is refracted, and the lift pin is positioned through proximal portions of the slots.
In another aspect, a method of operating a machine having a counterweight attachment and removal system includes loading a counterweight onto the machine by pivoting a link away from the machine and positioning a lift pin through distal portions of slots, wherein the slots are defined by two spaced apart arms of the link. Lift hooks of the counterweight are engaged with the lift pin. The link is then pivoted toward the machine, and the lift pin is moved from the distal portions of the slots to proximal portions of the slots.
In yet another aspect, a machine includes a frame and a pair of platforms supported on the frame. The machine also includes a counterweight attachment and removal system, which includes a machine mounting bracket supported on the frame and a link having two spaced apart arms. A proximal end of the link is pivotably coupled with the machine mounting bracket. A rotate cylinder has a proximal end pivotably coupled with the machine mounting bracket and a distal end pivotably coupled with a distal end of the link. A slide cylinder has a proximal end pivotably coupled with the link and a distal end pivotably coupled with a lift pin. The lift pin is positioned through slots defined by the two spaced apart arms. The counterweight attachment and removal system includes a first configuration in which the link is pivoted away from the machine, the rotate cylinder is retracted, the slide cylinder is extended, and the lift pin is positioned through distal portions of the slots. The counterweight attachment and removal system also includes a second configuration in which the link is pivoted toward the machine, the rotate cylinder is extended, the slide cylinder is refracted, and the lift pin is positioned through proximal portions of the slots.
An exemplary embodiment of a machine 10 is shown generally in
The counterweight 28, as should be appreciated, may be attached to the back end 30 of the machine 10 to counterbalance the weight of the implement system 22 mounted on the front end 20 of the machine 10. As shown in
Turning now to
As shown more clearly in
Preferably, the counterweight attachment and removal system 44 includes exactly two cylinders (i.e., the rotate cylinder 60 and the slide cylinder 82), as shown in the exemplary embodiment. Further, the two cylinders 60 and 82 are preferably positioned between two planes defined by the arms 54 of link 52. Each of the cylinders 60 and 82 may be hydraulic cylinders of conventional design including a tube portion and a piston portion arranged to form two separated pressure chambers. The pressure chambers may be selectively supplied with pressurized fluid and drained of the pressurized fluid to cause the piston portion to displace within the tube, thereby changing an effective length of the cylinders. The flow rate of fluid into and out of the pressure chambers may relate to a speed of cylinders, while a pressure differential between the two pressure chambers may relate to a force imparted by cylinders on the associated linkage members. The expansion and retraction of the cylinders 60 and 82 may function to assist in repositioning the counterweight attachment and removal system 44, as will be described below.
The link 52 may then be pivoted toward the machine 10, as shown in a second stage of the load operation in
It should be appreciated that “refracted” and “extended,” as used herein, may refer to cylinder positions that are fully refracted or extended, or may refer to cylinder positions that are substantially, but not fully, refracted or extended. For example, it may be desirable to only substantially retract the slide cylinder 82 such that, when the counterweight 28 is loaded, or attached, to the machine 10, it may be supported by the support platforms 40 rather than the slide cylinder 82 and other components of the counterweight attachment and removal system 44. Similarly, it may be desirable to only substantially retract or extend the rotate cylinder 60, rather than fully retracting or extending the cylinder 60.
At a fourth stage of the load, or attachment, operation, depicted in
To unload, or remove, the counterweight 28 from the machine 10, a reverse operation from that described above may be performed. Specifically, the lift pin 90 may be moved from the proximal portions 102 of the slots 92 to the distal portions 104 of the slots 92 by extending the slide cylinder 82. The link 52 may then be pivoted away from the machine 10 by retracting the rotate cylinder 60. It should be appreciated that the rotate cylinder 60 may be retracted to varying lengths, thus providing multiple unloading positions. For example, the rotate cylinder 60 may be fully, or substantially, retracted to unload the counterweight 28 to the ground. However, the rotate cylinder 60 may be only partially retracted to unload the counterweight 28 to a trailer or other platform. Once the counterweight 28 is supported on the ground or other desired surface, the lift pin 90 may be disengaged from the lift hooks 112 of the counterweight 28.
Turning now to
The present disclosure may be applicable to machines, such as work machines, utilizing a counterweight to counterbalance a load of the machine. Further, the present disclosure may be applicable to machines utilizing counterweights that must be unloaded from the machines, such as for separate transport or maintenance, and then loaded back onto the machines. Yet further, the present disclosure may be applicable to a counterweight attachment and removal system that has minimal components, occupies a limited amount of space on the machine, and requires minimal operator assistance.
Referring generally to
The counterweight attachment and removal system 44 disclosed herein may be supported on the rear end 30 of the machine 10 and may be used to load, or attach, the counterweight 28 onto the machine 10, and unload, or remove, the counterweight 28 from the machine 10. The back end 30 of the machine 10 may include a pair of support platforms 40 supported on the upper frame 16 for supporting the counterweight 28. The counterweight attachment and removal system 44 generally includes a machine mounting bracket 46 positioned between the two support platforms 40. A proximal end 56 of a link 52, which includes two spaced apart arms 54, is pivotably coupled with the machine mounting bracket 46. A rotate cylinder 60 has a proximal end 62 pivotably coupled with the machine mounting bracket 46 and a distal end 66 pivotably coupled with a distal end 68 of the link 52. A slide cylinder 82 has a proximal end 84 pivotably coupled with the link 52 and a distal end 88 pivotably coupled with a lift pin 90. The lift pin 90 is positioned through slots 92 defined by the two spaced apart arms 54, with opposing ends 94 and 96 of the lift pin 90 supporting the counterweight 28.
The counterweight 28 may be loaded onto the machine 10 by moving the counterweight attachment and removal system 44 to a first configuration, such as by using hydraulic controls, which may be positioned at the back end 30 of the machine 10, in the operator control station 26, or at another desired location. In the first configuration, the link 52 may be pivoted away from the machine 10 by retracting the rotate cylinder 60. The lift pin 90 may be positioned through distal portions 104 of the slots 92 by extending the slide cylinder 82. Next the lift hooks 112 of the counterweight 28 may be engaged with the lift pin 90. Alternatively, according to the embodiment of
To unload the counterweight 28 from the machine 10, a reverse operation may be performed. The reverse operation may be controlled using hydraulic controls positioned at a convenient location on the machine 10. Specifically, the lift pin 90 may be moved from the proximal portions 102 of the slots 92 to the distal portions 104 of the slots 92 by extending the slide cylinder 82. The link 52 may then be pivoted away from the machine 10 by retracting the rotate cylinder 60. When the counterweight 28 is moved to the desired supporting surface, such as, for example, the ground or a trailer, the lift pin 90 may be disengaged from the lift hooks 112 of the counterweight 28. According to the alternative embodiment of
The counterweight attachment and removal system disclosed herein may be provided on new machines or may be provided as a retrofit on current machines, and is an effective system for loading and unloading a counterweight relative to a machine. The counterweight attachment and removal system requires the use of a counterweight having structures, such as, for example, hooks or openings, configured to engage corresponding structures of the counterweight attachment and removal system, such as, for example, a lift pin or linkage. The counterweight attachment and removal system, which requires minimal operator assistance, comprises a relatively minimal number of components and occupies a relatively limited amount of space on the machine. Further, the counterweight attachment and removal system may be stowed entirely within a recessed area of the counterweight when the counterweight is loaded on the machine.
It should be understood that the above description is intended for illustrative purposes only, and is not intended to limit the scope of the present disclosure in any way. Thus, those skilled in the art will appreciate that other aspects of the disclosure can be obtained from a study of the drawings, the disclosure and the appended claims.