Patent Application
20050047898
The invention relates to supports for linkages for manipulating work tools such as, for example, buckets on loaders and other work vehicles. More specifically, it relates to a system and method of attaching the linkages to work vehicles.
On many work vehicles such as, for example, loaders, the mechanical performance of the linkage mechanism for manipulating a work tool, such as a bucket, is optimized, in part by the anchor position of the linkage on the frame, i.e., linkage pin location. It is sometimes difficult to gain the necessary optimal linkage pin location on the conventional frames on which these linkages are attached as the required locations may not be conducive to ease of frame manufacture.
In order to gain a desired or optimal performance from a linkage mechanism of a work vehicle it is sometimes necessary to place linkage pin supports in positions that are less than optimal with respect to the manufacturing process for a conventional frame. This, can lead to undesirable increases in the time and cost for manufacture of the frame with less than optimal linkage performance. Additionally, during the life of the work vehicle, there may be occasions when an alternate linkage pin location may be desired for optimal performance of the same or of a different linkage. With conventional vehicles, such a change would require another frame or another vehicle either of which would significantly increase costs.
The inventors recognize that the problems above have resulted from the use of conventional one-piece frames which include the linkage pin supports and have solved the above problems by providing a removable linkage pin support. This arrangement makes it possible to achieve optimal linkage performance without the concomitant increases in the time and cost for manufacture associated with conventional frames. The invention replaces the complex linkage pin support area of the conventional frame with a linkage pin support system which includes a removable linkage pin support and a load support area of the frame suitable for the rigid attachment of the removable linkage pin support to the frame. In practice, the frame and the removable linkage pin support are separately manufactured and, afterwards, rigidly assembled using attaching bolts or some other suitable method of attachment.
During the life of the work vehicle conditions may arise where changes in linkage pin support locations are desirable such as, for example, a change in terrain or a desire to use a linkage of a different configuration. As noted earlier, the costs for such a change on a work vehicle with a conventional frame would be substantial as a change of vehicle or, at the least, a change of frame would be required. The invention makes it possible to modify linkage pin locations on a work vehicle without incurring the associated time and cost difficulties of replacing the entire frame or vehicle as the removable linkage pin support may be replaced by another removable linkage pin support of a different configuration.
Embodiments of the invention will be described in detail, with reference to the following figures, wherein:
Mounted on the front frame 20 is a boom 50 that is partly formed by right and left arms 50a and 50b respectively. The right and left arms 50a and 50b are connected by a transverse cross tube 52 that is welded to each of the right arm 50a and the left arm 50b. The rear end of the boom 50 is connected to the mast 21 by transverse pivots 61 and 63 and a loader bucket 70 is mounted on the forward end of the boom 50 by transverse pivots 62 and 64. The boom 50 is rotated about transverse pivots 61 and 63 by hydraulic lift cylinders 65a and 65b, first ends of which are, respectively, connected to the front frame 20 at transverse pivots 65 and 67. Second ends of hydraulic lift cylinders 65a and 65b are, respectively, connected to the right and left arms 50a and 50b at transverse pivots 66 and 68.
The rotational location of the bucket 70 about the pivots 62 and 64 is controlled by a linkage 80 which, in this particular configuration, includes: a hydraulic tilt cylinder 81; left and right leveling links 82a and 82b; a bell crank 83, a guide link 84; and a bucket link 85. The hydraulic tilt cylinder 81 powers the linkage 80 and is connected to the bucket by the bell crank 83 which is mounted on a transverse pivot 90 at the front end of the leveling links 82a and 82b. The hydraulic tilt cylinder 81 is connected to a first end of the bell crank 83 by a transverse pivot 91 and a second end of the bell crank 83 is connected to a first end of the bucket link 85 by a transverse pivot 92. The bucket link 85 is mounted on a transverse pivot 93 at a second end of the guide link 84 and a first end of the guide link 84 is connected to the cross tube 52 via a transverse pivot 94 carried in a support 54 welded to the cross tube 52. A second end of the bucket link 85 is pivotally connected to the loader bucket 70 via a transverse pivot 95. As shown in
In practice, the locator bushings 123 are placed in the countersunk portions 121b′ and the linkage pin support 100 is assembled to the front frame 20 by placing the matching attachment holes 109b directly over the exposed areas of the locator bushings 123 and pressing the linkage pin support 100 down. The linkage pin support 100 is then rigidly attached to the front frame 20 via bolts 130a and 130b.
Having described the illustrated embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
