A blade assembly for an earthworking implement has a set of teeth that are independently slideable within guides. The teeth slide to conform to an undulating surface and permit scraping of the surface.

FIELD OF THE INVENTION

The present invention relates to a blade assembly for an earthworking implement for use in excavating.

SUMMARY OF THE INVENTION

The majority of excavation is performed by a vehicle equipped with a bucket, blade or the like, collectively referred to as an earthworking implement, that engages the soil and removes it to either a truck or to a storage area. Typically, such implements have a blade assembly with a leading edge for engagement with the soil. The leading edge may be either a single smooth edge or a toothed edge depending on the ground conditions.

The operators of the earth moving machines exhibit great dexterity in manipulating the implements so that the removal of the soil is accomplished with a minimal disturbance. However, in some operations the configuration of the leading edge prevents the efficient removal of the soil and turns the task into a relatively time consuming operation.

One such operation is removal of soil from an irregular surface such as a rock. The rock invariably has a contoured outer surface and the fixed linear leading edge found on the implement essentially establishes a single point contact. Even where a toothed edge is provided, multiple point contact is difficult to achieve and the net result is that the surface of the rock cannot be easily cleared of the soil. This hampers removal of the soil overburden, makes it difficult to ascertain the physical limits of the rock and leads to extraneous material being removed with the rock.

It is therefore an object of the present invention to provide a blade assembly for an earthworking implement in which the above disadvantages are obviated or mitigated.

In general terms the present invention provides a blade assembly for earthworking implement in which a soil engaging leading edge is segmented into a plurality of individual segments. Each segment can slide relative to the adjacent segment. The individual segments may then adopt a relative configuration that conforms to the contours of the surface over which the bucket is traversed.

Preferably, a biasing element such as a spring is used to bias the segments beyond the leading edge of the bucket.

In a further embodiment, the segments are hydraulically connected to link relative movements of the segments and accommodate the contours of the surface over which the edge is moved.

DETAILED DESCRIPTION OF THE INVENTION

Referring therefore toFIG. 1, an earthworking implement shown as an excavator bucket and generally indicated at10is arranged to be attached through lugs12,14to a boom of an earth moving machine (not shown) in a conventional manner. It will be appreciated that the exact form of the implement may vary according to the earth moving machine and maybe configured as a bucket to fit on the end of a 360° excavator boom, as a bucket for a front end loader or other commonly used configurations of bucket or as a blade of a dozer.

The bucket10has sidewalls16and a bottom wall18. Mounted to the underside of the bottom wall18is an attachment in the form of a blade assembly generally indicated at20that provides individual segments in advance of the leading edge of the bucket10.

The blade assembly20includes a plurality of teeth22, each of which has a shank24extending rearwardly from the tooth22. Each off the shanks24is slidably received within a respective tube26conveniently formed from a square section tubing welded to the underside of the base18. The shank24has a slot26that receives a pin28extending laterally through the tube26to limit movement. The pin28retains the shank24within the tube26and the square section inhibits rotation of the shank24relative to the tube26.

A spring32acts between an end wall34of the tube26and the shank24to bias the tooth22forwardly in advance of the base18.

It will be appreciated that each of the teeth22is independently movable against the force of the respective spring32. The tubes26act as guides for the shanks to constrain the teeth for sliding movement. The tubes26maintain the teeth24in generally planar alignment with the edges of the teeth defining a linear edge. The independent relative movement of the teeth22enables the teeth slide relative to one another to conform to the surface over which the teeth are moved, as indicated in chain dot lines and thereby perform a scraping action that is effective to remove the majority of the soil from the surface. Movement of the bucket is controlled by the boom operating cylinders in a normal manner and the independent movement allows a relatively smooth arc or wiping motion to be achieved with movement of the shank24within the tube26accommodating the irregularities of the surface over which the teeth22are moved.

An alternative embodiment is shown inFIGS. 4 through 6in which like components will be identified with like reference numbers with a suffix “a” added for clarity. In the embodiments ofFIGS. 4 through 6, the shanks26aconnected to the teeth22aare formed as piston rods that slide within hydraulic cylinders40. The shanks26aare connected to pistons42and each of the cylinders40is connected to a manifold44. The manifold44allows hydraulic communication between the cylinders40so that retraction of one of the teeth22acauses a corresponding extension of one or more of the other teeth22. Initially, the manifold44is filled such that each of the pistons42is positioned approximately half way along the cylinder40.

In use, the normal loads placed upon the teeth22amaintain the pistons42at a retracted position within the cylinder40. In this condition the teeth are aligned and present a linear edge. As the teeth22atraverse an irregular surface, the teeth will adjust through the hydraulic connection of the manifold to conform to the surface over which they are traversed. Thus, in the event that one of the teeth passes over a relatively shallow or concave portion, that tooth will extend and the adjacent teeth retract so that the teeth22aconform to the surface.

It will be seen therefore that in both embodiments, the teeth22aare allowed to conform to an irregular surface and thereby facilitate removal of soil from that surface.

A further embodiment of the blade assembly is shown inFIGS. 7 through 11where like components will be identified with like reference numerals with the suffix b added for clarity. In the embodiments ofFIGS. 1 through 6, the blade assembly20is mounted directly to the base18of the implement. In the embodiment ofFIGS. 7 through 11, the blade assembly is made as a separate unit that can be mounted to the base18in either a permanent or dismountable manner.

Referring therefore toFIG. 7, the blade assembly20bincludes a set of teeth22beach of which has a square section shank24b. The shank24bis slidably mounted within tubes26b, also of square cross section. The tubes26bare mounted in parallel spaced relationship to a mounting plate50such that the teeth22bform a substantially continuous transverse edge. As can be seen fromFIG. 8, a brace52extends across the opposite face of the tubes26band mounting arms54project outwardly for connection to the bucket10through suitable mounting pins. Pins may also be used to connect the plate50to the base plate18or the plate50may be welded directly to the base plate15if the connection is to be permanent.

A hydraulic cylinder40bis located within each of the tubes26band secured by a pin56that extends through each of the tubes26b. A piston rod42bprojects from each of the cylinders40bwithin the tubes26band is connected by way of a pin58to the shanks24b.

The cylinder40bhas a head side port46that is connected to the manifold44b. The manifold44bincludes T-couplings48and hoses49that form a continuous connection between each of the head side ports46such that cylinders40bare connected in parallel. One end of the manifold includes a check valve that allows the cylinders40bto be charged with hydraulic fluid.

As in the embodiment ofFIGS. 4 through 6, the cylinders40bare filled such that the pistons42bare approximately one half of the travel along the cylinder40b.

In use, the teeth22bare initially aligned to present a linear cutting edge. The resistance to flow of the hydraulic fluid and the sliding connection of the shanks24bwithin the tubes26benable the teeth22bto remain aligned during normal digging operations. In the event that a surface is to be cleaned, one or more of the teeth22bwill extend relative to the other teeth22band allow the teeth22bto conform generally to the uneven surface. Such an arrangement is indicated more clearly inFIG. 11. The teeth22bmay then pass across the surface and adjust continually to the undulations of the surface and thereby allow soil to be removed from the surface.

As noted above, the attachment shown inFIG. 7 through 11may be permanently connected to the bucket10or may be selectively mounted on the implement when cleaning operations are to be performed.

It will be apparent that moderate biasing of the pistons to a retracted position through the use of coil springs within the rod side of the cylinder40bmay assist in avoiding the teeth from extending under the influence of gravity during transport or the like. Such springs would not affect the ability of the teeth to accommodate undulations in the surface.

It will also be apparent that the blade assemblies shown inFIG. 1 to 3,4,7through11may be mounted on to the blade of a dozer allowing the lower edge of the blade to conform to the surface or an other earthworking machine to permit efficient cleaning operations.