US 3743126 A
A control linkage for articularly mounting a loader bucket on a supporting vehicle. The linkage includes a main boom and a secondary boom, with the main boom pivotally mounted on the vehicle and with links connecting the secondary boom to the main boom and with the bucket pivotally mounted on the secondary boom. A hydraulic cylinder is mounted on the vehicle and is connected to the main boom for raising and lowering the bucket, and another hydraulic cylinder is connected with the bucket for tipping the bucket. The linkage and boom pivot mounting are arranged so that the bucket can be raised in a flatened curve and so that the bucket is in an optimum forward position when raised, and the operator has maximum visability of the bucket. That is, the boom is pivoted on the vehicle at a point lower than that required for achieving the raised forward position of the bucket, and thus the operator has improved visability of the bucket.
Description (OCR text may contain errors)
United States Patent [1 1 Seaberg ] Appl. No.: 221,624
 US. Cl. 214/776, 214/140  Int. Cl E02f 3/00  Field of Search 214/776, DIG. 10,
 References Cited UNITED STATES PATENTS 10/1962 Garske 214/776 Kromer 214/776 Primary ExaminerGerald M. Forlenza Assistant Examiner-John Mannix Attorney-Arthur J. Hansmann [4 1 July 3,1973
[5 7] ABSTRACT A control linkage for articularly mounting a loader bucket on a supporting vehicle. The linkage includes a main boom and a secondary boom, with the main boom pivotally mounted on the vehicle and with links connecting the secondary boom to the main boom and with the bucket pivotally mounted on the secondary boom. A hydraulic cylinder is mounted on the vehicle and is connected to the main boom for raising and lowering the bucket, and another hydraulic cylinder is connected with the bucket for tipping the bucket. The linkage and boom pivot mounting are arranged so that the bucket can be raised in a flatened curve and so that the bucket is in an optimum forward position when raised, and the operator has maximum visability of the bucket. That is, the boom is pivoted on the vehicle at a point lower than that required for achieving the raised forward position of the bucket, and thus the operator has improved visability of the bucket.
10 Claims, 2 Drawing Figures LOADER BUCKET CONTROL LINKAGE This invention relates to control linkage for articularly mounting a loader bucket on a supporting vehicle and, more particularly, it relates to providing a loader bucket mounting wherein the operator has optimum vision of the bucket, the bucket is raised to a forwardmost position for dumping the bucket, and the bucket is raised in a relatively flattened curve or upright path for minimum required clearance of raising the bucket and for optimum balance of the entire machine.
BACKGROUND OF THE INVENTION The prior art has long been concerned with the provision of mountings for loader buckets wherein the buckets have the advantages mentioned in the foregoing paragraph. Many and varied teachings exist to achieve the goal of solving the problems and providing bucket mountings which have the desired features mentioned. Numbers of patents have issued on the subject of control linkage or bucket mountings, but these patents commonly require that the bucket be mounted on one end of a boom which has its other end pivoted to a supporting vehicle. This then results in the bucket swinging on an arc, the midpoint of which are presents the bucket in an undesirable forward position such that the entire machine is unstable, and the single boom type mounting also has the disadvantage of requiring that the boom be pivoted to the vehicle at a relatively high elevation on the vehicle so that the bucket can be swung from a low position to a high raised position. That type of bucket mounting does not achieve the advantages mentioned above.. Additionally, a bucket boom is known to be mounted on a supporting vehicle in a manner wherein the boom is not connected to the vehicle by means of one fixed pivot mounting, but the pivot mounting itself may be movable, such as shown in U. S. Pat. No. 2,538,000. However, that type of construction has the boom which is directly supporting the bucket mounted to the vehicle at a point high on the vehicle, and, in fact, the point is movable to where it even approximates the elevation of the raised bucket, and that type of construction is expensive, complex, and likely to be tempermental in its functioning. Another example of a prior art structure where the boom which supports the bucket is not pivoted on the vehicle on a fixed axis is seen in U. S. Pat. No. 3,209,930, but that teaching also requires a high mounting for the boom, and the actual physical support of the boom is not a stable one in that it depends entirely upon the swinging of the supporting links about their respective arcs as shown in that patent.
Accordingly, it is an object of this invention to provide a control linkage or mounting for a loader bucket onto a vehicle and wherein the linkage, including the booms, is connected at a low elevation on the vehicle so that the operator has optimum vision of the bucket in its working positions.
Still another object of this invention is to provide control linkage or a mounting for a loader bucket and wherein the bucket can be positioned in a forwardmost position when the bucket is raised, and this is for purposes of dumping the bucket into a truck or any other dump spot. In accomplishing this object, it will be understood that the bucket does not simply swing about a fixed axis on the vehicle, but the bucket actually is positioned beyond the arc which would otherwise be scribed if the bucket were supported on a boom fixed to the vehicle.
Still another object of this invention is to accomplish any or all of the aforementioned objectives, and to do so with a bucket control linkage or mounting which is of maximum sturdy character to support maximum loads without overbalancing the machine, and to do so with a minimum of parts and without complicated parts which are not reliable in operation.
Other objects and advantages will become apparent on reading the following description.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a control linkage of this invention, and showing the linkage in the raised position in dotted lines, and also showing the supporting vehicle in dot-dash lines.
FIG. 2 is a schematic view of the control linkage shown in FIG. 1, on a slightly enlarged scale, and also showing the position of the linkage in the raised position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings indicate a tractor type of vehicle 10 which is shown in dot-dash lines, and the loader bucket 11 is articularly mounted on the vehicle 10 by means of the mounting or control linkage generally designated 12. The linkage 12 includes a main boom 13 and a secondary boom 14, and the two booms are articularly connected together by means described later. The boom or arm 13 is pivotally mounted at one end theref on the vehicle 10 and at a fixed pivot pin or the like 16. Lift means inrthe showing of a hydraulically powered cylinder 17 is connected to the vehicle at a pin 18 and is connected to the boom 13 at a pin 19. Thus the extension and contraction of the hydraulic cylinder unit 17 will cause the pivot action of the boom 13 about its fixed mounting pin 16.
A first link 18 and a second link 19 are articularly connected to the booms l3 and 14 by connecting pins 21 and 22, on the link 18 and connecting pins 23 and 24, on the link 19. Thus the links 18 and 19 are described as being connected to the end of the boom 13 opposite from the boom end 26 where the pivot 16 is located. Likewise, the links 18 and 19 are connected to the secondary boom 14 at the end of the boom 14 opposite from the boom end where the bucket 11 is located, and it will be seen that the bucket 1 1 is pivotally mounted on the end 27 of the boom 14 by means of the pivot pin 28.
Thus the links 18 and 19 and the booms l3 and 14 present a four-bar or parallelogram linkage, as shown. To stabilize that linkage, the link 18 has its lower end 29 extending downwardly to where it connects to a link 31 through a pin 32. In turn, the link 31 is pivoted on the vehicle 10 at the pivot pin 33 which is fixed relative to the vehicle 10.
With the control linkage described thus far, it will now be understood that identical linkage exists on the opposite side of the vehicle 10, and the linkage is swingable or pivotal about the fixed pins 16 and 33, for raising and lowering the bucket 11. Thus, from the solid line position shown in FIG. 1, the control linkage thus far described can be moved into the raised position shown by the dotted lines. When the bucket 1.1 is
raised as indicated, it' will be noticed and understood that the bucket 11 is essentially as far forward in the raised position as it is in the lowered position shown in FIG. 1, even though the pivot mountings 16 and 33 are substantially closer to the elevation of the bucket in the lowered position. This is one desirable feature of this control linkage in that the bucket 11 can then be dumped over a truck or any other dump site which requires that the bucketbe high but as far forward as is needed or as is required for stability of the entire machine.
In connection with the feature of the forward position of the bucket 11 when the bucket is raised, FIG. 2, in dotted lines, shows the bucket 11 in lhe raised position, and it also shows an are 34 which traces the swing of the bucket 11 from its lowered solid-line position to its raised dotted line position, and the arc 34 has a center marked C on the vehicle 10. That is, to achieve the forward raised position for the bucket 11 by virtue of a single boom, or like bucket mounting, the mounting would have to be as high as the center designated C in FIG. 2. That height or elevation of location for center C affects the stability of the machine, and it interferes with the operators visability of the bucket and the material being handled by the bucket, since the center C is too high on the vehicle 10, and of course that center C is above the mounting point 16.
Further, FIG. 2 shows the bucket in the substantially half way or horizontal position of lift, by location of the bucket pin 28, and it will again be noted that the pin 28 is inside the are 34 and therefore the bucket 11 does not require the large swing of the path as designated by the are 34, but instead the bucket 11 follows the flatter curve of swing and this provides for the desirable flat or somewhat vertical lift of the bucket 11.
Another observation is that if the bucket 11 were pivoted on the vehicle about one fixed pivot point and through one boom connected to that pivot point and to the bucket 11, that boom would then have the bucket pin 28 scribe the are designated 36 in FIG. 2. It will then be understood that the are 36 would not cause the bucket to be positioned in its desired and actual raised and forwardmost position as shown in FIGS. 1 and 2. The arc 36 is struck about the lower fixed pivot point 16, so that while that arrangement would provide for the desired lower mounting of the boom, it would not position the bucket 11 in the forwardmost position as described.
To understand the forward position of the raised bucket 11, observation is made of the link 18 and its control link 31. Thus, from the lowered position and the orientation of link 18, the raising of the link 18 does not cause the link 18 to become vertically disposed, to say nothing of causing it to be oriented to tilt rearwardly at the top. Instead, the link 18 is oriented to tilt forwardly at the top and in the raised position, and this positions the secondary boom 14 to a forward position. Therefore, the fixed pivot point 33 is located rearwardly and at an elevation lower than the location of the fixed pivot 16.
The bucket has a tilt control which includes a hydraulic cylinder 41 which is connected to the upper end of the-link 18 through the pin 42. A link 43 is pivoted at its lower end on a pin 44 on the secondary boom 14, and the ram end of the cylinder 41 is connected to the link 43 through a pin 46. Finally, a link 47 is connected to the upper end of the link 43 through a pin 48 and is connected to the bucket 11 through a pin 49. Thus there is an articular connection between the control linkage described and the bucket 11 for the tilt action of the bucket 11. Further, the arrangement described in connection with the articular connectors for tilting the bucket is such that the bucket will remain at least substantially horizontal or in the same attitude, whether or not that be horizontal, when the cylinder 41 is not operating but when the lift cylinder 17 is operated so that the bucket is swung from the lowered position to a raised position, all as indicated in FIG. 1. Of course FIG. 2 shows the cylinder unit 41 somewhat extended so that the bucket 11 is tipped somewhat forward and may be considered to be in a digging position when it is in the lower position in FIG. 1, and it has substantially the same position when it is raised, as seen in FIG. 1, though the cylinder 41 had not been extended or contracted.
The links and booms described may exist, and preferably do, on each side of the vehicle 10, in the known arrangement of control linkage or support means for a loader bucket of this nature. Also, the boom or arms 13 may be connected by a cross shaft extending across the vehicle 10 to provide more frame stability, if suchbe necessary or desirable. Also, the control linkage or structure described achieves the result of a high lift for the bucket 1 1 though there is a low profile or mounting of the linkage relative to the vehicle 10, and, the bucket in the lifted position is substantially directly above the bucket in the lowered position, and that lift position is the forward positon described. It will also be noticed that the one link 18 has an action which is not along an arcuate path about either fixed pivot mounting 16 or 33, with respect to the upper end of the one link 18, and, in fact, the link 18 moves substantially vertically upwardly rather than rotate about a pivot axis. Also, the pivot mounting 33 is lower than the elevation of the mounting 16, and it is rearwardly thereof relative to the vehicle 10. Still further, the arc scribed by the articular connection pin 22 is such that it is crossed by the arc scribed by the articular connection 32 when the bucket is lifted, so the link 18 has the action mentioned. That is, the connection pin 32 is rearward of .the pin 22 even when the bucket is in the raised position, as shown by the dotted lines in FIG. 1 and as shown by the pin locations in FIG. 2.
What is claimed is:
1. Control linkage for articularly mounting a loader bucket on a supporting vehicle, comprising a main boom vertically pivotally mounted at one end thereof on said vehicle, a lift means operatively connected with said main boom for vertically pivoting said main boom, a secondary boom having one end articularly connected with said bucket, two links articularly connected between said booms and forming a four-bar linkage with said booms, an additional link pivotally mounted on said vehicle and articularly connected with one of said two links for controlling the attitude of said one link throughout the raising and lowering of said bucket, and bucket pivot-control means connected to said bucket for controlling the pivot of said bucket on said secondary boom in loading and unloading of said bucket.
2. The control linkage as claimed in claim 1, wherein said main boom is disposed at an elevation below that of said secondary boom.
3. The control linkage as claimed in claim 2, wherein said one link extends downwardly to an elevation below that of the pivot mounting of said main boom, and the articulate connection between said one link and said additional link being at said elevation on said one link.
4. The control linkage as claimed in claim 3, wherein said bucket pivot-control means is articularly connected with said one link.
5. The control linkage as claimed in claim 1, wherein said bucket pivot-control means is articularly connected with said secondary boom.
6. The control linkage as claimed in claim 1, wherein said booms are articularly connected together by said two links being connected to said booms at the respective ends thereof opposite said one ends of each said booms.
7. The control linkage as claimed in claim 6, wherein said one link and said bucket pivot-control means are articularly connected together, and said lift means and said bucket pivot-control means are hydraulic cylinder units.
8. The control linkage as claimed in claim 6, wherein the pivot mounting of said additional link is disposed at a location to cause the end of said one link opposite its said one end to move substantially upwardly, rather than in a true arcuate path, during the lifting of said bucket.
9. The control linkage as claimed in claim 8, wherein said location is at an elevation lower than that of the pivot mounting of said main boom.
10. The control linkage as claimed in claim 9, wherein said pivot mountings of said main boom and said additional link, and their respective articular connections with said one link, are located to have the arc of movement of said articular connection for said additional link cross the arc of movement of said articular connection for said main boom, in the lifting of said bucket.