SCRAPER BLADE HAVING TRIP EDGE AND FLOATING EDGE

Description

BACKGROUND

Scraper blades such as snowplows are typically mounted directly to a vehicle to remove debris such as dirt, snow and ice from the ground surface directly in front of the vehicle. Snowplows with fixed cutting-edge sections often strike obstacles during clearing operations, such as frozen debris, rocks, road curbs, and manhole covers. As a result, the lowermost cutting-edge section of the plow blade may become damaged and need to be replaced. Further, roads having crowned or uneven surfaces may cause some portions of the blade to contact the road while other portions of the blade are raised above the road leaving unplowed snow or other debris to pass under the blade.

Several different mechanisms have been developed in attempts to overcome the problems set out above. Instead of being fixed, some scraper blades have individual cutting-edge section sections that are slidingly received within guide pockets on the moldboard and are biased downwardly by springs. The cutting-edge sections retract upwardly into the pockets when adjusting to the contour of the ground or striking an obstacle. Other scraper blades are mounted to plow bodies with a resilient trip mechanism that allows the cutting-edge section to pivot rearwardly upon striking an obstacle and to be restored to an operative position after moving over the obstacle. U.S. Pat. No. 9,611,604 (Vigneault) describes an exemplary snowplow having both a retracting edge mechanism and a trip edge mechanism and the disclosure is incorporated by reference.

While scraper blades having movable cutting-edge sections tend to do a better job of removing snow from uneven surfaces than conventional blades with a fixed cutting-edge section, there remains a need for improved cutting-edge systems. One problem with existing scraper blade systems having a movable cutting edge (e.g., retracting and/or trip edge features) is the complexity of the mechanisms necessary to move the cutting-edge section between its various positions. Some existing mechanisms require multiple springs, one spring to bias the retracting mechanism in its downward position and another spring to bias the trip edge in its forward position. Other existing mechanisms require a plurality of linkages connected by pins or gears between the spring and the movable cutting-edge section. These complex mechanisms are expensive to manufacture and include many parts, which makes them more prone to failure.

There is therefore a need for an improved scraper blade which overcomes these and other problems in the art.

SUMMARY

One aspect of the present invention relates to a scraper blade assembly configured to be carried by a vehicle over a ground surface. The scraper blade assembly comprises a moldboard combined with a plurality of surface engaging assemblies extending from a lower portion of the moldboard in side-by-side relationship with one another. Each surface engaging assembly has a linkage assembly and a cutting-edge section. Each surface engaging assembly is movable about a trip pivot axis relative to the moldboard between an operational position and a tripped position. Each cutting-edge section is linearly movable between an extended position and a retracted position. The linkage assembly is configured to move the surface engaging assembly between the operational position and the tripped position and the cutting-edge section between the extended position and the retracted position. A biasing member is combined with the linkage assembly and configured to provide a biasing force to urge the surface engaging assembly toward the operational position and the cutting-edge section toward the extended position. The linkage assembly includes a first linkage having a body portion, a first portion movable around a first linkage pivot axis, and a second portion operatively engaged with the cutting-edge section, and a second linkage having a body portion, a first portion movable around a second linkage pivot axis (which may be the same as the trip pivot axis), and a second portion operatively combined with the biasing member.

Another aspect of the present invention relates to a scraper blade assembly having a moldboard combined with a plurality of surface engaging assemblies, wherein each assembly is configured to trip rearward to pass obstacles underneath and float upwardly to contour to the ground. The plurality of surface engaging assemblies extend from a lower portion of the moldboard in side-by-side relationship with one another. Each surface engaging assembly includes a cutting-edge section configured to contact the ground during operation and a linkage assembly configured to allow the surface engaging assembly to move between its various positions. Each surface engaging assembly is movable around a trip pivot axis relative to the moldboard between an operational position and a tripped position wherein obstacles are allowed to pass underneath the cutting-edge section. In addition, each cutting-edge section is linearly movable between an extended position and a retracted position wherein the cutting-edge section floats linearly (generally upward) to contour to the ground. The linkage assembly is operatively combined with a biasing member. In one embodiment, the biasing member provides a biasing force to urge the surface engaging assembly toward the operational position and the cutting-edge section toward the extended position. The linkage assembly includes a first linkage and a second linkage. The first linkage includes a body portion, a first portion movable around a first linkage pivot axis relative to the moldboard, and a second portion operatively engaged with the cutting-edge section. The second linkage includes a body portion, a first portion movable around a second linkage pivot axis (which may be the same as the trip pivot axis) relative to the moldboard, and a second portion operatively combined with the biasing member. The body portion of the first linkage is configured to engage the body portion of the second linkage, either directly or indirectly, so the biasing force of the biasing member causes the second linkage to urge the surface engaging assembly toward the operational position and the cutting-edge section toward the extended position.

Another aspect of the present invention is similar to the ones described above, except there are two biasing members, each acting on different linkage assemblies which are operatively engaged with different portions of the cutting-edge section.

Another aspect of the present invention relates to a method of operating the scraper blade assembly described above. The method includes attaching the snowplow to a prime mover vehicle, such as a truck or skid steer loader, and operating the prime mover vehicle over the ground surface with the cutting-edge section engaging the ground surface. Upon encountering an obstacle, moving the surface engaging assembly rearward around a trip pivot axis relative to the moldboard from an operational position to a tripped position so the obstacle can pass underneath the cutting-edge section. After the obstacle is behind the cutting-edge section, the biasing member urging the linkage assembly to move the surface engaging assembly back to the operational position. Upon encountering a change in the contour of the ground, floating one or more cutting-edge sections linearly (generally upward) from the extended position to the retracted position to match the contour of the ground. The biasing member urging the linkage assembly to move the cutting-edge section toward the extended position engaging the ground surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of the scraper blade wherein the surface engaging assembly is in the operational position and the cutting-edge section is in the extended position.

FIG. 2 is a rear perspective view of the scraper blade wherein the surface engaging assembly is in the operational position and the cutting-edge section is in the extended position.

FIG. 3 is a side view of the scraper blade wherein the surface engaging assembly is in the operational position and the cutting-edge section is in the extended position.

FIG. 4 is a side view of a section of the surface engaging assembly with some components hidden for better visibility of the linkages.

FIG. 5 is a rear exploded view of a section of the surface engaging assembly.

FIG. 6 is a rear perspective view of the scraper blade wherein one of the surface engaging assemblies is in the tripped position.

FIG. 7 is a side view of a section of the surface engaging assembly wherein the surface engaging assembly is in the tripped position.

FIG. 8 is a front perspective view of the scraper blade wherein one of the cutting-edge sections is in the retracted position.

FIG. 9 is a side view of a section of the surface engaging assembly wherein the cutting-edge section is in the retracted position.

DETAILED DESCRIPTION

FIGS. 1-3 generally show an embodiment of the scraper blade described herein, which may be a snowplow in some embodiments. The scraper blade includes a moldboard 10 having a generally curved plowing face. The scraper blade includes a plurality of surface engaging assemblies 12, each assembly 12 configured to move in two directions in response to different ground conditions. Each assembly 12 is configured to trip/pivot rearwardly to pass obstacles underneath and also allowing the cutting-edge section 14 to float linearly (generally upwardly) to contour to the ground. The plurality of surface engaging assemblies 12 extend from a lower portion of the moldboard 10 in side-by-side relationship with one another. Each assembly 12 is movable between its various positions independent from the position of the other assemblies 12. Each surface engaging assembly 12 includes an edge carrier 15, a cutting-edge section 14, and a linkage assembly 19. The edge carrier 15 provides support and rotates with the surface engaging assembly 12. The cutting-edge section 14 includes a lowermost edge configured to contact the ground during operation. The cutting-edge section 14 rotates with the surface engaging assembly 12 and also floats linearly to contour the ground. A mounting assembly 18 is configured to attach the scraper blade to a prime mover vehicle, such as a truck, skid steer, or UTV.

FIGS. 4 and 5 show a surface engaging assembly 12 and biasing member 16 separate from the other components of the scraper blade. The surface engaging assembly 12 includes a linkage assembly 19 having a first linkage 20 and a second linkage 22. Each surface engaging assembly 12 is movable around a trip pivot axis A relative to the moldboard 10 between an operational position (FIGS. 3 and 4) and a tripped position (FIGS. 6 and 7) wherein obstacles are allowed to pass underneath. The trip pivot axis A extends in a direction generally parallel to the width (long axis) of the moldboard 10 so the surface engaging assembly 12 can pivot rearward relative to the normal/forward direction of travel during plowing operations. Each cutting-edge section 14 is also linearly movable between an extended position (FIGS. 3 and 4) and a retracted position (FIGS. 8 and 9) within channel 17 as described below in more detail.

The biasing member 16 is operatively combined with the linkage assembly 19 to provide a biasing force on the linkage assembly 19. In some embodiments, each biasing member 16 serves multiple functions. First, each biasing member 16 urges the surface engaging assembly 12 forward toward the operational position (FIGS. 3 and 4). Second, each biasing member 16 urges the cutting-edge section 14 downward toward the extended position. Having a single biasing member 16 serve both functions simplifies the assembly. As shown in FIGS. 2 and 5 and described below in more detail, some embodiments include multiple biasing members 16 acting on a single surface engaging assembly 12 through separate linkage assemblies 19. In these embodiments each biasing member 16 of the multi-biasing member 16 assembly is configured to perform both of the functions described above.

The biasing member 16 may be a spring or any other suitable member capable of exerting a biasing force. As shown in the figures, the biasing member 16 is a spring that is compressed when the cutting-edge section 14 encounters an obstacle and trips the surface engaging assembly 12 to the tripped position or when the contour of the ground raises and the cutting-edge section 14 floats upward to the retracted position. The spring urges the components back to their biased position by pushing downwardly on the second linkage 22. In an alternate embodiment (not shown) the components are configured so a biasing member 16 such as a tension spring is extended or pulled upon when encountering an obstacle or adjusting to the contour of the ground and urges the components back to their biased position by retracting back to its original position.

As shown in FIG. 5, the first linkage 20 includes a body portion 20a, a first portion 20b, and a second portion 20c. The first portion 20b is pivotally combined with the surface engaging assembly 12 so the first linkage 20 is movable around a first linkage pivot axis B relative to the moldboard 10. The second portion 20c is operatively engaged with the cutting-edge section 14. The second linkage 22 includes a body portion 22a, a first portion 22b, and a second portion 22c. The first portion 22b is pivotally combined with the surface engaging assembly 12 so the second linkage 22 is movable around a second linkage pivot axis relative to the moldboard 10. The second linkage pivot axis is the same as the trip pivot axis A in the illustrated embodiments, but may be another pivot axis generally parallel to trip pivot axis A in other embodiments. The second portion 22c is pivotally combined with the biasing member 16. It should be noted that combining one element of the assembly described herein to another element of the assembly described herein may be done indirectly with an intermediate component (not shown) between the two elements. Direct connection/contact between the components is not required as long as there is operative connection.

FIGS. 4, 7, and 9 show side views where some components of the assembly have been removed to better show the first linkage 20 and the second linkage 22. The body portions 20a, 22a of each linkage 20, 22 have curved surfaces. The opposing curved surfaces are configured to engage and roll/slide along each other as the surface engaging assembly 12 moves to the various positions. Each linkage 20, 22 has a portion that pivots about an axis A, B, and the pivot axis B of the first linkage 20 is generally parallel to the pivot axis A of the second linkage 22 so the body portions 20a, 22a of each linkage 20, 22 can move generally in the same direction and the same plane. This allows the linkages 20, 22 to engage and act on each other as each moves around its pivot axis A, B either in the direction of the biasing force or against the biasing force.

In another embodiment, the linkages 20, 22 are positioned in separate but parallel planes and indirectly connected by gears, pins, or other fasteners. In this embodiment the motion of one linkage 20 causes movement of the other linkage 22 via the fasteners connecting the linkages 20, 22 rather than by direct content between the linkage body portions 20a, 22a.

The surface engaging assembly 12 is configured to trip rearward from an operational position (FIGS. 3 and 4) to a tripped position (FIGS. 6 and 7) upon encountering a sudden discontinuity/obstacle. The biasing member 16 exerts a biasing force (generally downward toward the ground surface in some embodiments) on the second linkage 22 causing the second linkage 22 to pivot the surface engaging assembly 12 forward around trip pivot axis A toward the operational position. Upon encountering an obstacle, the surface engaging assembly 12 (edge carrier 15, cutting-edge section 14, and linkage assembly 19) rotates rearward around trip pivot axis A until the obstacle is able to move under the cutting-edge section 14. The tripped position is not a single set position since it may change depending on the size of the obstacle encountered. For smaller obstacles the tripped position will require less rotation around trip pivot axis A and for larger obstacles the tripped position will require more rotation around trip pivot axis A. Once the obstacle is no longer acting on the cutting-edge section 14, the biasing member 16 urges the assembly 12 back to the operational position. As mentioned above, each surface engaging assembly 12 operates independently so one or more surface engaging assemblies 12 may trip while the others remain in the operational position.

The cutting-edge section 14 is configured to float linearly (generally upward) from an extended position to a retracted position to contour to gradual changes of the ground surface/elevation without tripping rearward. Each cutting-edge section 14 is linearly movable within a channel 17 formed in the surface engaging assembly 12 between an extended position (FIGS. 3 and 4) and a retracted position (FIGS. 8 and 9). The cutting-edge section 14 moves relative to the edge carrier 15. The biasing member 16 exerts a biasing force (generally downward toward the ground surface in some embodiments) on the second linkage 22. The body portion 22a of the second linkage 22 is configured to engage the body portion 20a of the first linkage 20 so the biasing force is transferred through the second linkage 22 to the first linkage 20 to urge the second portion 20c of the first linkage 20 and the cutting-edge section 14 downward toward the extended position (FIG. 4). Upon encountering an increased ground elevation, the cutting-edge section 14 is forced upward in the channel 17 causing the first linkage 20 to move in the same direction. Since the first linkage 20 is not directly combined with the biasing member 16, the first linkage 20 engages the second linkage 22 against the biasing force of the biasing member 16 such that both linkages 20, 22 rotate around their respective axis A, B against the biasing force as the cutting-edge section 14 moves to the retracted position. While the linear float of the cutting-edge section 14 causes the second linkage 22 to pivot about the second linkage pivot axis A, it does not cause the entire surface engaging assembly 12 to pivot as described in the previous paragraph. For this reason, the second linkage pivot axis may be different from the trip pivot axis A for the surface engaging assembly 12 in some embodiments. The retracted position is not a single set position since it may change depending on the contours of the ground. For small elevation changes the cutting-edge section 14 will require less linear motion, and as such the first linkage 20 less rotation around first linkage pivot axis B. For larger elevation changes the retracted position will require more rotation of the first linkage 20 around first linkage pivot axis B. As mentioned above, each surface engaging assembly 12 operates independently so one or more may float upwardly at different elevations depending on the contour of the ground surface.

As mentioned above and shown in FIGS. 2 and 5, some embodiments include more than one biasing member 16 and linkage assembly 19 acting on a single surface engaging assembly 12. A first biasing member 16 and first linkage assembly 19 act on a first portion of the surface engaging assembly 12 and a second biasing member 16 and linkage assembly 19 act on a second portion of the surface engaging assembly 12. The first portion may be near a first end of the cutting-edge section 14 and the second portion may be near a second end of the cutting-edge section 14. The second portions 20c of the first linkages 20 for each of the first linkage assembly 19 and the second linkage assembly 19 are combined with the respective portions of the cutting-edge section 14. Applying a biasing force to each side of the assembly 12 allows the cutting-edge section 14 to tilt laterally as it floats upward to contour to the ground surface. In other words, the first side of the cutting-edge section 14 may float to a different elevation than the second side of the cutting-edge section 14 since each side is urged toward the engaged position by a separate biasing member 16 and moves to the retracted position by a separate linkage assembly 19.

Having thus described the invention in connection with the preferred embodiments thereof, it will be evident to those skilled in the art that various revisions can be made to the preferred embodiments described herein without departing from the spirit and scope of the invention. It is my intention, however, that all such revisions and modifications that are evident to those skilled in the art will be included within the scope of the following claims.

Claims

1. A scraper blade assembly configured to be carried by a vehicle over a ground surface, said scraper blade assembly comprising: a moldboard combined with a plurality of surface engaging assemblies extending from a lower portion of the moldboard in side-by-side relationship with one another, wherein each surface engaging assembly has a linkage assembly and a cutting-edge section;each surface engaging assembly is movable about a trip pivot axis relative to the moldboard between an operational position and a tripped position;each cutting-edge section is linearly movable between an extended position and a retracted position; anda biasing member combined with the linkage assembly and configured to provide a biasing force to urge the surface engaging assembly toward the operational position and the cutting-edge section toward the extended position;wherein the linkage assembly is configured to move the surface engaging assembly between the operational position and the tripped position and the cutting-edge section between the extended position and the retracted position.
2. The scraper blade assembly of claim 1 wherein the linkage assembly includes: a. a first linkage having a body portion, a first portion movable around a first linkage pivot axis, and a second portion operatively engaged with the cutting-edge section; andb. a second linkage having a body portion, a first portion movable around a second linkage pivot axis, and a second portion pivotally combined with the biasing member.
3. The scraper blade assembly of claim 2 wherein the first linkage pivot axis and the second linkage pivot axis are generally parallel so the first linkage and the second linkage are configured to rotate in the same plane.
4. The scraper blade assembly of claim 2 wherein the body portion of the first linkage engages the body portion of the second linkage so that movement of the first linkage against the biasing force causes movement of the second linkage against the biasing force.
5. The scraper blade assembly of claim 2 wherein the trip pivot axis is the same as the second linkage pivot axis.
6. The scraper blade assembly of claim 1 wherein the second portion of the first linkage is directly combined with the cutting-edge section and the second portion of the second linkage is directly combined with the biasing member.
7. The scraper blade assembly of claim 2 wherein the body portion of the first linkage has a curved surface and the body portion of the second linkage has a curved surface, and the curved surface of the first linkage engages and is configured to engage along the curved surface of the second linkage as the surface engaging assembly moves.
8. A scraper blade assembly configured to be carried by a vehicle over a ground surface, said scraper blade assembly comprising: a moldboard combined with a plurality of surface engaging assemblies extending from a lower portion of the moldboard in side-by-side relationship with one another, wherein each surface engaging assembly has a linkage assembly and a cutting-edge section;each surface engaging assembly is movable about a trip pivot axis relative to the moldboard between an operational position and a tripped position;each cutting-edge section is linearly movable between an extended position and a retracted position;wherein the linkage assembly has a first linkage operatively engaged with the cutting-edge section and pivotally movable around a first linkage pivot axis, and a second linkage combined with a biasing member and pivotally movable around a second linkage pivot axis;wherein the biasing member is configured to transmit a biasing force to the second linkage thereby biasing the surface engaging assembly toward the operational position, and wherein the second linkage is configured to transmit the biasing force to the first linkage thereby biasing the cutting-edge section toward the extended position.
9. The scraper blade assembly of claim 8 wherein the first linkage has a body portion, a first portion movable around the first linkage pivot axis, and a second portion operatively engaged with the cutting-edge section; and the second linkage has a body portion, a first portion movable around a second linkage pivot axis, and a second portion pivotally combined with the biasing member.
10. The scraper blade assembly of claim 8 wherein the first linkage pivot axis and the second linkage pivot axis are generally parallel so the first linkage and the second linkage are configured to rotate in the same plane.
11. The scraper blade assembly of claim 9 wherein the body portion of the first linkage engages the body portion of the second linkage so that movement of the first linkage against the biasing force causes movement of the second linkage against the biasing force.
12. The scraper blade assembly of claim 9 wherein the first linkage is indirectly combined with the second linkage by a fastener.
13. The scraper blade assembly of claim 8 wherein the second portion of the first linkage is directly combined with the cutting-edge section and the second portion of the second linkage is directly combined with the biasing member.
14. The scraper blade assembly of claim 9 wherein the body portion of the first linkage has a curved surface and the body portion of the second linkage has a curved surface, and the curved surface of the first linkage engages and is configured to engage along the curved surface of the second linkage as the surface engaging assembly moves.
15. A scraper blade assembly configured to be carried by a vehicle over a ground surface, said scraper blade assembly comprising: a moldboard combined with a plurality of surface engaging assemblies extending from a lower portion of the moldboard in side-by-side relationship with one another, wherein each surface engaging assembly includes a cutting-edge section configured to contact the ground during operation;each surface engaging assembly is movable about a trip pivot axis relative to the moldboard between an operational position and a tripped position;each cutting-edge section is linearly movable between an extended position and a retracted position, wherein each cutting-edge section has a first portion and a second portion;a first linkage assembly combined with the first portion of the cutting-edge section, wherein the first linkage assembly is configured to move the surface engaging assembly between the operational position and the tripped position and the first portion of the cutting-edge section between the extended position and the retracted position;a first biasing member combined with the first linkage assembly and configured to provide a first biasing force to urge the surface engaging assembly toward the operational position and the first portion of the cutting-edge section toward the extended position;a second linkage assembly combined with the second portion of the cutting-edge section, wherein the second linkage assembly is configured to move the surface engaging assembly between the operational position and the tripped position and the second portion of the cutting-edge section between the extended position and the retracted position;a second biasing member combined with the second linkage assembly and configured to provide a second biasing force to urge the surface engaging assembly toward the operational position and the second portion of the cutting-edge section toward the extended position.
16. The scraper blade assembly of claim 15 wherein the first linkage assembly and the second linkage assembly each have a first linkage and a second linkage, each of the first linkages having a body portion, a first portion movable around a first linkage pivot axis, and a second portion operatively engaged with the cutting-edge section; and each of the second linkages having a body portion, a first portion movable around a second linkage pivot axis, and a second portion pivotally combined with the biasing member.
17. The scraper blade assembly of claim 15 wherein the first linkage pivot axis and the second linkage pivot axis are generally parallel so the first linkage assembly and the second linkage assembly are configured to rotate in the same plane.
18. The scraper blade assembly of claim 16 wherein the body portion of the first linkages engages the body portion of the second linkages so that movement of the first linkages against the biasing forces causes movement of the second linkages against the biasing forces.
19. The scraper blade assembly of claim 16 wherein the first linkages are indirectly combined with the second linkages by fasteners.
20. The scraper blade assembly of claim 15 wherein the second portions of the first linkages are directly combined with the cutting-edge sections and the second portions of the second linkages are directly combined with the biasing members.

SCRAPER BLADE HAVING TRIP EDGE AND FLOATING EDGE

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Description

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