RESONANTLY DRIVEN EARTH MOVER

Abstract: An improved version of applicant's prior bull­ dozer mold board assemblies is disclosed. Such prior assemblies include a mold board (16), a reciprocating cutter blade (18) along the lower edge of the mold board, and a resonant beam mounted aft of the mold board. The vibration of the beam results in a recip­ rocating force at the node, which is undesirable in applicant's prior device. The present invention improves on applicant's former construction by pivotably support­ ing the mold board so that the mold board is pivotable about a transverse axis. The resonant beam is connected at its central node to the mold board. In this fashion, and reciprocating transverse forces on the node of the resonant beam are transmitted to the pivotably mounted mold board to agitate the material in contact therewith.

Description: The present invention relates to a machine for moving earth and other material, such as a bulldozer, front end loader or like machine, according to the precharacterizing part of claim 1. The mold board of such a machine is resonantly driven to both cut and agitate the material to be moved. In this context the term "mold board" includes both the type of mold board used in a bulldozer and a shovle used in a front end loader. U.S. Patent 4,359,102 shows such a bulldozer having a reciprocating cutter blade at the base of the mold board and a resonant beam for driving the cutter blade intermittently forwardly to cut the material to be dozed. With this known bulldozer the mold board is secured to the rigid frame assembly. This bulldozer construction has been found to be quite useful because it loosens the earth to be moved by the bulldozer, substantially reducing the force that must be applied to dislodge the earth and the size of the tractor needed to advance the mold board. However, this construction still is not as efficient as desired, because the earth and other material, once dislodged by the cutter, remains compacted together and is difficult to move. Various prior devices have attempted to break up the earth and make it easier to move. U.S. Patent 3,443,327 shows a front end loader with a shaker for vibrating the entire shovel. U.S. Patent 3,770,322 shows a mold board which is shaken by an oscillator. U.S. Patent 3,367,716 shows a similar arrangement. Unfortunately, these devices provide immense stresses on the mold board, and vibrate the overall system, making them impractical. Also, such devices in effect combine the cutting and agitation functions, and have been found not to be as effective as desired for either task. It is therefore an object of the present invention to provide an improved machine for moving earth and other material which retains all of the advantages of having a cutter blade separate from the mold board which reciprocates to cut the material to be moved and which is further capable of fluidizing the material dislodged by the cutter blade and thus can be used to efficiently move large amounts of material. According to the present invention the problem is solved in that the mold board is pivotably supported by the rigid frame assembly, with the mold board and the cutter blade being independently pivotably suspended from the rigid frame assembly. The vibration of the beam results in a reciprocating force at the node, which was undesirable in the prior device as described in U.S. Patent 4,359,102. The present invention improves this former construction by pivotably supporting the mold board so that the mold board is pivotable about a transverse axis. The resonant beam is connected at its central node to the pivotable mold board. In this fashion, the reciprocating transverse forces on the node of the resonant beam are transmitted to the pivotably mounted mold board to agitate the material in contact therewith. The present invention provides a unique construction which retains all of the advantages of having a cutter blade separate from the mold board which reciprocates to cut the earth to be moved. Using the same resonant beam that drives the cutter blade, the mold board itself is separately and independently agitated, thus fluidizing the material dislodged by the cutter blade. This relatively straightforward construction both cuts the material loose and fluidizes the material, rendering it much easier to move. As a result, a relatively small bulldozer can be used to efficiently move large amounts of material. The invention will be better understood from the following description considered in connection with the accompanying drawings in which a preferred embodiment of the invention is illustrated by way of example. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a bulldozer incorporating a preferred embodiment of the present invention; FIG. 2 is a side elevation view of the mold board assembly of the embodiment of of FIG. 1; FIG. 3 is a top view of the mold board assembly of FIG 2; FIG. 4 is a section view taken along lines 4-4 of FIG. 3 and showing the attachment of the resonant beam; FIG. 5 is a section view taken along lines 5-5 of FIG. 3 and showing the frame support for the mold board and cutter blade; FIG. 6 is a section view taken along lines 6-6 of FIG. 3 and showing the suspension of the cutter blade; and FIG. 7 is a perspective view of a second embodiment of the present invention in which the mold board has a pair of sections forming a V-shaped plow. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring initially to FIG. 1, a bulldozer 10 incorporating a preferred embodiment of the present invention includes a conventional tractor 12 having a pair of beams 14 for operating a mold board 16. A cutter blade 18 is located along the bottom edge of mold board 16. Mold board 16 and cutter blade 18 are manipulated using a pair of lift cylinders 20, and a tilt cylinder 22. Referring in addition to FIG. 2, beams 14 are connected to a transverse box beam 24 by a pin connection 26. Box beam 24 is part of a rigid frame assembly 24, 28, 36 which also includes a plurality of vertical ribs 28, each of which has a curved front surface 30 conformed to the shape of the back side of mold board 16. In the preferred embodiment shown, surface 30 is formed by a transverse pad 32 attached to a flange 34 on the front surface of each rib 28. Each pad 32 is approximately 7,62-15,24 cm (3-6 inches) wide. Referring to FIGS. 2, 3 and 5, a second transverse box beam 36 spans the top ends of rib 28. Box beams 24 and 36 are welded to ribs 28 to form the rigid frame assembly 24, 28, 36. In addition, arms 38 are welded to transverse box beams 36 and extend upwardly and forwardly. A cylindrical sleeve 40 is welded to the top end of each arm 38. A plurality of cylinders 42 complementary to cylinders 40 are welded along the upper edge of the mold board 16. A pin 46 extends through the complementary sleeves 40, 42 to suspend mold board 16 from the top of the frame assembly 24, 28, 36. As illustrated in FIG 4, resonant beams 48 each include a pair of legs 50, 51 joined at a central juncture 52. Leg 50 has an input end 53 which houses an oscillator. The oscillator is driven by a motor 54 coupled to the oscillator by a universal assembly 56. When motor 54 drives the oscillator at near the resonant frequency of beam 48, it vibrates in a near resonant mode (i.e., close to resonance but not so close as to cause structural damage to the beam), with its node at the central juncture 52 and antinodes at the ends of legs 50, 51. Resonant beam 48 also has an enlarged force transmitting end 60 at the end of leg 51. Cutter blade 18 is mounted on a blade support 62 having an aft striking surface 64 in close proximity to force transmitting end 60 of resonant beam 48. As illustrated in FIG. 5, arms 66 depend from transverse box beam 24 of the frame assembly 24, 28, 36, and a pin connection 68 to blade support 62 limits the travel of cutter blade 18. As is evident from FIG. 4, legs 50, 51 of resonant beam 48 have an included angle, directed toward mold board 16, of approximately 90 degrees. Extending inwardly between legs 50, 51 from central juncture 52 is a flange 70 having a pair of ears 71, 72. A mounting plate 74 is attached to the back side of mold board 16 by legs 76-78. Bolts 79, 80 rigidly attach ears 71, 72 to mounting plate 74 so that the central juncture 52 of resonant beam 48 is directly connected to mold board 16. As illustrated in FIG. 6, cutter blade 18 and blade support 62 are suspended on pivot arms 82. Pivot arms 82 are in turn pivotably supported by pin connection 84 to the upper box beam 36 of the frame assembly 24, 28, 36. Cutter blade 18, as well as mold board 16, are thus independently pivotably suspended from the frame assembly 24, 28, 36. When motor 54 rotates the universal assembly 56 comprising a universal shaft, the oscillator in the input end 53 of resonant beam 48 causes the beam to vibrate in near resonance. Force transmitting end 60 of resonant beam 48 strikes the back surface, namely the striking surface 64 of blade support 62, driving cutter blade 18 intermittently forwardly into the earth or other material to be moved to cut the material loose. The vibration of resonant beam 48 causes reciprocating forces to be established at the node located at the central juncture 52 along the axis of flange 70. These reciprocating forces are transmitted directly to mold board 16 to reciprocate the mold board about the pivotal support along its top edge. An alternative embodiment 86 of the bulldozer of the present invention is illustrated in FIG. 7. In this embodiment, a conventional tractor 88 similar to that illustrated in the first embodiment is used. However, in this bulldozer 86, the mold board consists of a pair of mold board sections 89, 90 with separate cutter blade sections 91, 92 at the respective lower edges. A plate 94 extends outwardly between mold board sections 89, 90 to form a plow having a V-shape. As in the first embodiment, mold board sections 89, 90 and cutter blade sections 91, 92 are suspended from a frame assembly, and independently driven by angle beams to both cut the material loose and agitate the material so that it can be moved more readily. For example, the construction illustrated could be adopted to earth moving machines similar to bulldozer, such as a front end loader.

Claims: Machine for moving earth and other material, such as a bulldozer, front end loader or like machine, comprising a tractor (12; 88), a mold board (16; 89, 90), a rigid frame assembly (24, 28, 36) supporting said mold board (16; 89, 90), means (14, 20, 22) for coupling said rigid frame assembly (24, 28, 36) to said tractor (12; 88), a cutter blade (18; 91, 92) along the lower edge of said mold board (16; 89, 90), with said cutter blade (18; 91, 92) being pivotably suspended from said rigid frame assembly (24, 28, 36), and a resonant beam (48) mounted aft of the mold board (16; 89, 90) having an input end (53) at which an oscillator is provided for vibrating said resonant beam (48) near its resonant frequency, a central node at which said resonant beam (48) is connected to said mold board (16; 89, 90), and a force transmitting end (60) proximate said cutter blade (18; 91, 92) for driving said cutter blade (18; 91, 92) intermittently forward into the material to be moved, characterized in that said mold board (16; 89, 90) is pivotably supported by said rigid frame assembly (24, 28, 36), with said mold board (16; 89, 90) and said cutter blade (18; 91, 92) being independently pivotably suspended from said rigid frame assembly (24, 28, 36). Machine according to claim 1, characterized in that said resonant beam (48) includes a juncture (52) at the location of said central node and a pair of legs (50, 51) emanating from said juncture (52) and having an included angle directed towards said mold board (16; 89, 90) of less than 180 degrees. Machine according to claim 2, characterized in that the included angle between said pair of legs (50, 51) directed towards said mold board (16; 89, 90) is approximately 90 degrees. Machine according to claim 2 or 3, characterized in that said resonant beam (48) includes a flange (70) extending inwardly between the legs (50, 51) of said resonant beam (48), and in that said resonant beam (48) is attached to said mold board (16; 89, 90) via said flange (70). Machine according to claim 4, characterized in that the back side of said mold board (16; 89, 90) includes a mounting plate (74), and in that said flange (70) of said resonant beam (48) is attached to said mounting plate (74). Machine according to anyone of the preceding claims, characterized in that said coupling means (14, 20, 22) comprises means (20, 22) for manipulating the position and inclination of said rigid frame assembly (24, 28, 30) relative to said tractor (12; 88). Machine according to claim 6, characterized in that said rigid frame assembly (24, 28, 36) includes a plurality of vertical ribs (28), each rib (28) having a forward edge conformed to the shape of the back surface of said mold board (16; 89, 90) in close abutment therewith to restrict aft movement of said mold board (16; 89, 90) pivotably suspended from said rigid frame assembly (24, 28, 36). Machine according to claim 7, characterized in that the forward edge of each rib (28) includes a pad (32) conformed to the shape of the back surface of said mold board (16; 89, 90). Machine according to anyone of the preceding claims, characterized in that said mold board (16; 89, 90) is pivotably supported proximate the top edge of said mold board (16; 89, 90).

Inventors: GURRIES, RAYMOND A.
Applicants: RENO SALVAGE COMPANY
Application year: 1988
Main classification: E02F3
IPC codes: E02F3, E02F5