Patent Application
20060120843
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The present invention pertains generally to apparatus for moving loads between lowered and inclined positions, and more specifically to such an apparatus comprising a load-carrying body pivotally supported on a base for selective pivotal movement between a lowered position and an inclined position by a four-pivot axis linkage mechanism comprising at least first and second pivotal linkages.
Dumping vehicles have long been known as a means of moving cargo, including refuse such as dirt, sand, etc., from one location to another. It has also long been known that a quick way to discharge the contents of a loaded dumping vehicle is to move the load-containing body to an inclined position, thus causing the contents to move downwardly along the inclined body by the force of gravity. Most essentially, the means for accomplishing inclined positioning of the load body comprise a pivotal connection between that body and a supporting framework, and means for selectively pivoting the cargo body between lowered and inclined positions thereof. Such means for selective pivoting are known to include manually operable means as well as powered means including, for example, hydraulic mechanisms. An exemplary dumping vehicle comprising powered means for the inclined positioning of the load body is shown in Day, U.S. Pat. No. 2,542,799.
Over the years, various mechanisms have been devised for pivotally connecting a load body to a supporting framework in a dumping vehicle. Inter alia, these have included the mechanism of Frazier, U.S. Pat. No. 1,658,236, which discloses a dumping wagon having an automatic dumping body connected to a frame by a double toggle joint comprising a plurality of pivotal links. As specified in that patent, the double toggle joint includes a pair of forward pivotal links disposed just ahead of the center of gravity of the dumping body, and a pair of pivotal links disposed rearward of the center of gravity. Both pairs of links are pivotally connected to the frame in coplanar pivot axes. According to the disclosure of Frazier, the foregoing arrangement results in the automatic movement of the dumping body to the inclined position thereof when a load is carried in the dumping body, and, conversely, automatic movement of the empty dumping body to the lowered position thereof.
Notwithstanding this and other modifications to the basic mechanism for inclining a cargo body in a dumping vehicle, there has not, to date, been provided a simple mechanism for facilitating the movement of a load between lowered and inclined positions under conditions where the relative force required to move a load-carrying body to the inclined position has been significantly reduced for both manual and powered inclining means.
The present invention addresses and solves the problems discussed above, and encompasses other features and advantages, by providing an apparatus comprising a load-carrying body having a center of gravity, the load-carrying body pivotally supported on a base for selective pivotal movement between a lowered position and an inclined position by a four-pivot axis linkage mechanism comprising at least first and second pivotal linkages. The apparatus is characterized by a fully lowered position of the load-carrying body, wherein the center of gravity of the load-carrying body is positioned approximately above the at least first linkage, a fully inclined position of the load-carrying body, wherein the entire load-carrying body is shifted rearwardly in relation to the base and the center of gravity of the load-carrying body is positioned rearwardly of both of the at least first and second pivotal linkages, and an intermediate position, wherein the center of gravity of the load-carrying body is positioned intermediate of the at least first and second linkages. The linkage mechanism is operative to carry the load-carrying body rearwardly in relation to the base along a path of travel between the fully lowered, intermediate, and fully inclined positions of the load-carrying body, during which path of travel the center of gravity of the load-carrying body is lowered between the fully lowered and intermediate positions thereof, and raised between the intermediate and fully inclined positions thereof. In this manner, the present invention functions to utilize the energy of a load to move the cargo body to the inclined position thereof, while dissipating excess energy.
According to one feature hereof, the first pivotal linkage comprises at least one pivot arm having a fixed first length defined between upper and lower ends, the upper end of the at least one pivot arm being connected to the base for pivotal movement relative thereto about a first pivot axis, and the lower end of the at least one pivot arm being pivotally connected to the body for pivotal movement relative thereto about a second pivot axis. The second pivotal linkage comprises at least one pivot arm having a fixed second length defined between upper and lower ends, the upper end of the at least one pivot arm being connected to the base for pivotal movement relative thereto about a third pivot axis, and the lower end of the at least one pivot arm being pivotally connected to the body for pivotal movement relative thereto about a fourth pivot axis. The first length of the at least one pivot arm of the first pivotal linkage is greater than the second length of the at least one pivot arm of the second pivotal linkage, the first pivot axis is defined vertically above the third pivot axis, and the first pivotal linkage is positioned closer to the front end of the body than the second pivotal linkage.
According to another feature of this invention, the load body further comprises downwardly extending, laterally spaced-apart struts, each of the struts defining one of the second and fourth pivot axes.
According to still another feature hereof, a reinforcing member is provided which extends between the spaced-apart struts, providing torsional rigidity thereto.
Per yet another feature of the present invention, means are provided for assisting the powered or manual movement of the body between the lowered and inclined positions thereof. Such means may include, by way of non-limiting example, a manually graspable arm provided on the cargo body, an hydraulic piston, a powered or manually operable jack-screw, etc.
According to one feature of this invention, the base comprises a pair of laterally spaced-apart frame members, the at least one pivot arm of the first pivotal linkage comprises a substantially planar, rigid member disposed between the spaced-apart frame members, and the at least one pivot arm of the second pivotal linkage comprises a substantially planar, rigid member disposed between the spaced-apart frame members.
Per still a further feature hereof, the apparatus comprises a wheeled base, according to which the invention may be employed as a dumping vehicle.
Referring now to the drawings, wherein like or corresponding numerals indicate like or corresponding parts throughout the several views, the present invention will be seen to most generally comprise an apparatus for facilitating the movement of a load between lowered and inclined positions.
More particularly, and with reference being had first to
But while the present invention is shown in use in a dumping trailer, it will be appreciated from this written specification and the accompanying drawings that the apparatus of this invention may be adapted to numerous other operational environments where it is desired to facilitate the selective assisted movement of a load from a lowered to an inclined position. Thus, by way of non-limiting example, the apparatus may be mounted as a bucket on an earth-moving vehicle, such as a front-end loader, may be incorporated into a conveyor system employed to transport loads from one place to another, or may be incorporated into powered vehicles, such as a dump truck.
Still referring to
Base 30 may likewise take a number of forms. In the illustrated embodiment of this invention, base 30 comprises a rigid metal, trailer-style framework including, in conventional fashion, a pair of frame members 31 which are laterally spaced-apart and disposed approximately parallel to each other proximate the rear half of the framework. These frame members 31 are angled inwardly and come together towards the front of the framework where, in the illustrated embodiment, a trailer hitch 32 is provided for securing the base 30 to a conveying vehicle, such as an automobile. One or more transverse frame members (not depicted) spanning the frame members 31 may be provided for rigidity, as known. Proximate the forward end-wall 18 of the cargo body 15 the base 30 is provided with the striker portion 33 of a latch mounted upon an upwardly projecting support 34. In corresponding position on the lower portion of the forward end-wall 19 of the load body 15 is disposed the locking portion 35 of the latch. As shown, the base 30 includes one or more wheels 36, either free-spinning or motor-driven, as desired, connected to the framework 31.
Referring now to
As best depicted in
Pivot arms 42 and 52 are, according to the illustrated embodiment, defined by rigid, substantially planar shear plates oriented transversely of the longitudinal axis of the base 30. Pivot arms 42 and 52 are formed of a suitable material, such as, for instance, metal, so as to resist planar stresses. In the illustrated form, each such pivot arm 42, 52 is particularly defined by a pair of sheets of suitably strong metal, such as steel plate, one of which plates is bent proximate its lateral ends to define reinforcing end-walls, as shown, and to provide exact spacing against a trim edge for sleeves or tubes 45, 55 described elsewhere herein. But while this configuration of the pivot arms 42 and 52 is advantageous in providing pivoting linkages well-suited to withstanding flexing, the present invention is not intended to be so limited. Thus, by way of example, it is contemplated that the at least first and second pivotal linkages 41 and 51 may comprise four separate pivot arms, two disposed on each of the two opposing frame members 31 and each pivoting about one of the pair of pivot axes A1, A2 or A3, A4 in a more traditional four-bar style linkage.
In order to facilitate pivotal attachment to the body 15 and base 30 according to the illustrated embodiment, each pivot arm 42 and 52 is provided at the opposite upper and lower ends (43, 44 and 53, 54, respectively) thereof with a sleeve or tube 45, 55, respectively, each such sleeve having a bore therethrough dimensioned to rotatably receive therein one of the four axles or rods 60 defining pivot axes A1-A4.
Referring also to
Referring specifically to
The pivot axle 60 defining pivot axis A3 is secured to spaced-apart frame members 31. The first pivot axis A1 is defined vertically above the third pivot axis A3. In the illustrated embodiment more particularly, the first pivot axis A1 is defined approximately 3½ inches above the third pivot axis A3. To achieve the foregoing configuration, one of a pair of rigid mounting plates 37 may be fixed to each of the frame members 31 as depicted, each mounting plate 37 defining a point of attachment for an end of the pivot axle 60 defining the pivot axis A1. Of course, those of skill in the art will, with the benefit of this disclosure, appreciate that alternate means of positioning the first pivot axis A1 above the third pivot axis A3 may be employed. Thus, for instance, it is contemplated that pivot axle 60 defining the axis A1 may be secured directly to the frame members 31, with the mounting plate 37 depending downwardly therefrom to provide a vertically lower point of attachment for the pivot axle defining the pivot axis A3. And while the mounting plates 37 are shown as separate elements affixed to the frame members 31, it is contemplated that the same could be formed integrally with other components of the base 30.
As desired, the apparatus of this invention may include means for assisting the manual or powered movement of the body 15 between the lowered and inclined positions thereof. According to the illustrated embodiment, depicting manual movement means, there may, for example, be provided an arm 27 connected to the load body 15 and projecting therefrom. As will be appreciated, the arm 27 is of suitable size and shape to be manually grasped by a user, who may then use the same to effect the pivotal movement of the load body 15. Optionally, the arm 27 may further be operatively connected to the locking portion 35 of the aforementioned latch in order to selectively effect the locking engagement thereof with the striking portion 33, as well as locking and unlocking the tail gate, if provided. Alternatively, powered means may be provided. Such means may, for instance, comprise an inclined linear actuator provided between the base 30 and load body 15, a scissors mechanism operating between base 30 and load body 15, straight line generators designed to amplify the stroke of a linear actuator, etc. In addition, a linear actuator may be attached between pivot arms 41 and 51 to provide assistance by reacting one arm against the other.
Turning now to
Referring first to
The intermediate position (
In the fully inclined (
As shown best in
Those skilled in the art will of course appreciate that while pivoting movement of the cargo body 15 is described in relation to the pivot axes A1-A4, the first 41 and second 51 linkages are interdependent and function to in fact move the cargo body 15 about an infinite series of imaginary points.
By virtue of the foregoing arrangement, it will be appreciated that the apparatus of this invention facilitates the movement of a load from a lowered to an inclined position with significantly less— or, in the case of a balanced load, even no—force than is required to move a comparable load from a lowered to an inclined position in a dump vehicle wherein the load body is simply pivotally connected to a supporting frame at a single pivot axis.
It will be appreciated from the above disclosure that the present invention improves upon the prior art by providing simple mechanism for facilitating the selective assisted movement of a load between lowered and inclined positions under conditions where the relative force required to move a load-containing cargo body to the inclined position has been significantly reduced for both manual and powered pivoting means.
Of course, the foregoing is merely illustrative of the present invention, and those of ordinary skill in the art will appreciate that many additions and modifications to the present invention, as set out in this disclosure, are possible without departing from the spirit and broader aspects of this invention as defined in the appended claims. For instance, it will be appreciated that any of the absolute distances of the linkage mechanism provided herein are not intended to be limiting of the present invention, and may be modified without departing from the spirit and broader aspects hereof.
