Dual-mode pusher box attachment

Abstract

A dual-mode pusher box attachment for a powered material-handling machine includes:(a) a frame detachably mountable to the machine; and (b) a pusher box pivotably mounted to the frame for pivoting between a first position and a second position. When the pusher box is in the first position, a working face of the pusher box faces generally forward for pushing material, with sidewalls of the pusher box positioned to laterally retain material in a material collection space adjacent the working face during the pushing. When the pusher box is in the second position, the working face faces rearward for back-dragging material, with the sidewalls positioned to laterally retain material in the material collection space during the back-dragging.

Description

FIELDThe present application claims the benefit of U.S. Provisional Patent Application No. 63 / 792,570 filed Apr. 22, 2025, which is hereby incorporated herein by reference in its entirety.

[0002] The teachings disclosed herein relate generally to material handling, and more particularly, to pusher box attachments mountable to powered material-handling machines.INTRODUCTION

[0003] U.S. Pat. No. 9,885,160 (Stone) discloses a snow pusher, also known as a box plow, having a blade that is configured to be disposed in a first position for pushing snow forwardly, as is typical of snow pushers, and is further configured to be disposed in a second position for pulling snow rearwardly. The blade of the snow pusher may be contained within a snow plow box that may be reversible, allowing the blade to be disposed at a rear of the box for pushing the snow forwardly and at a front of the box for pulling snow rearwardly.

[0004] U.S. Pat. No. 7,448,453 (Tobin) discloses a vehicle-mounted tool, such as a blade, that may be disposed in an upright position for dozing or other pushing functions when the vehicle moves forwardly and then flipped over into an inverted position for back-dragging or the like when the vehicle moves in reverse. Flipping of the blade is accomplished using a cylinder operated from the seat of the vehicle. The blade is mounted on a swivel head that is controlled by a pair of oppositely actuating swivel cylinders from the operator's seat so that whether the blade is upright or inverted, it may be swivelled left or right into any number of obliquely disposed positions.

[0005] U.S. Pat. No. 6,470,604 (Foster et al.) discloses a snowplow attachment for mounting to the front end of a vehicle that includes both a push blade operable during forward movement of vehicle and a pull blade operable during reverse movement of the vehicle. The pull blade drops down in front of the push blade such that pushed snow can then be pulled back. During the push mode, the pull blade is raised to avoid interference with pushed snow. The snowplow can include side plates located on the ends of the blades for containing the snow and prevent snow from escaping out the sides, thereby increasing the volume of snow moved by the plow during one sweep.SUMMARY

[0006] The following summary is intended to introduce the reader to various aspects of the applicant's teaching, but not to define any invention.

[0007] According to some aspects, a dual-mode pusher box attachment for a powered material-handling machine includes (a) a frame having a frame axis between a rear and a front of the frame, the frame including a mounting portion at the rear for detachably mounting the attachment to the machine, and a pair of arms spaced laterally apart from each other and projecting along the frame axis from the mounting portion to the front of the frame; and (b) a pusher box laterally between and pivotably mounted to the pair of arms for pivoting about a lateral pivot axis relative to the frame between an upright pusher position and a pivoted back-drag position. The pusher box includes a blade wall having a working face extending vertically between opposed top and bottom cutting edges fixed relative to the working face and oriented parallel to the lateral pivot axis. The working face extends laterally between a pair of sidewalls fixed relative to and projecting from the working face. The sidewalls have respective inboard surfaces directed toward each other for laterally enclosing a material collection space adjacent the working face. Each inboard surface extends vertically along the working face between opposed first and second sidewall edges of the sidewall. The first and second sidewall edges project from the working face adjacent respective first and second cutting edges. When the pusher box is in the pusher position, the working face of the blade wall faces generally forward away from the machine for pushing material received in the material collection space forwardly along a substrate surface below the attachment, with the bottom cutting edge at an elevation below the top cutting edge and adjacent the substrate surface for material engagement to facilitate the pushing, and the first sidewall edge of the sidewalls adjacent and generally parallel with the substrate surface to inhibit material from spilling laterally from the material collection space during the pushing. When the pusher box is in the back-drag position, the working face of the blade wall faces generally rearward toward the machine for back-dragging material received in the material collection space rearwardly along the substrate surface, with the top cutting edge at an elevation below the bottom cutting edge and adjacent the substrate surface for material engagement to facilitate the back-dragging, and the second sidewall edge of the sidewalls adjacent and generally parallel with the substrate surface to inhibit material from spilling laterally out from the material collection space during the back-dragging.

[0008] In some examples, each first sidewall edge comprises a respective first skid shoe for sliding engagement with the substrate surface when the pusher box is in the pusher position. In some examples, each second sidewall edge comprises a second skid shoe for sliding engagement with the substrate surface when the pusher box is in the back-drag position.

[0009] In some examples, the pair of sidewalls are pivotably supported by respective arms of the frame for pivoting of the pusher box about the pivot axis, the pivot axis intersecting the sidewalls and fixed relative to the frame.

[0010] In some examples, the attachment includes one or more actuators coupled between the pusher box and the frame, the one or more actuators energizable to urge pivoting of the pusher box between the pusher position and the back-drag position. In some examples, the attachment includes a pair of the actuators coupled between respective sidewalls of the pusher box and the frame.

[0011] In some examples, the attachment includes an integrated trip system permitting limited pivoting of the pusher box from the pusher position toward the back-drag position to accommodate swinging of the bottom cutting edge rearwardly and upwardly upon impact with an obstacle on the substrate surface, and urging the pusher box back toward the pusher position when the obstacle is cleared.

[0012] In some examples, the trip system comprises one or more spring-loaded trip mechanisms coupled between the pusher box and the frame. In some examples, the one or more spring-loaded trip mechanisms are operable independent of the one or more actuators.

[0013] In some examples, each actuator comprises a hydraulic cylinder having a rod slidable in a cylinder housing between a first position corresponding to the pusher position and a second position corresponding to the back-drag position.

[0014] In some examples, the attachment comprises a hydraulic coupling assembly for fluidly connecting the hydraulic cylinder to a hydraulic system of the machine, and the trip system comprises a hydraulic accumulator integrated with the hydraulic coupling assembly, the hydraulic accumulator permitting limited movement of the rod from the first position toward the second position in response to hydraulic pressure exceeding a threshold activation pressure of the hydraulic accumulator.

[0015] In some examples, the blade wall has a window for visibility of the material collection space through the blade wall by an operator of the machine when operating the pusher box in the pusher position.

[0016] In some examples, the pusher box has a pair of stops fixed relative to and projecting laterally outwardly from respective outboard surfaces of the sidewalls, the pair of stops positioned for engagement with respective abutment surfaces fixed relative to the pair of arms of the frame to limit pivoting of the pusher box past the back-drag position.

[0017] In some examples, the frame is spaced vertically above the substrate surface when the attachment is mounted to the vehicle.

[0018] According to some aspects, a dual-mode pusher box attachment for a powered material-handling machine includes: (a) a frame detachably mountable to the machine; (b) a pusher box pivotably mounted to the frame for pivoting about a lateral pivot axis relative to the frame between a first position and a second position, the pusher box including a blade wall having a working face extending vertically between opposed first and second cutting edges of the blade wall. The working face extends laterally between a pair of sidewalls fixed relative to and projecting from the working face for laterally enclosing a material collection space adjacent the working face. When the pusher box is in the first position, the working face of the blade wall faces generally forward away from the machine for pushing material received in the material collection space along a substrate surface, with the first cutting edge at an elevation below the second cutting edge and adjacent the substrate surface for material engagement, and the sidewalls adjacent the substrate surface to inhibit material from spilling laterally from the material collection space during the pushing. When the pusher box is in the second position, the working face of the blade wall faces generally rearward toward the machine for back-dragging material received in the material collection space, with the second cutting edge at an elevation below the first cutting edge and adjacent the substrate surface for material engagement.

[0019] In some examples, when the pusher box is in the second position, the sidewalls are positionable adjacent the substrate surface to inhibit material from spilling laterally out from the material collection space during the back-dragging.

[0020] In some examples, each sidewall has a first skid shoe for sliding engagement with the substrate surface when the pusher box is in the first position, and a second skid shoe spaced apart from the first skid shoe for sliding engagement with the substrate surface when the pusher box is in the second position.

[0021] In some examples, the attachment includes a pair of actuators coupled between respective sidewalls of the pusher box and the frame, the pair of actuators energizable to urge pivoting of the pusher box between the pusher and back-drag positions.

[0022] In some examples, the frame has a pair of arms spaced laterally apart from each other and projecting forward from the mounting portion, and the pusher box is laterally between and pivotably mounted to the pair of arms.

[0023] According to some aspects, a method of moving material includes: (a) mounting a frame of a pusher box attachment to a powered material-handling machine, the frame pivotably supporting a pusher box of the attachment; and (b) pivoting the pusher box relative to the frame about a lateral pivot axis between a pusher position and a back-drag position. In the pusher position, a working face of the pusher box faces generally forward away from the machine with a pair of sidewalls of the pusher box projecting from the working face to laterally enclose a material collection space adjacent the working face. In the back-drag position, the working face of the pusher box faces generally rearward toward the machine. The method further includes (c) when the pusher box is in the pusher position, pushing material received in the material collection space of the pusher box with the working face during forward operation of the machine, with the sidewalls positioned to laterally retain the material in the material collection space during the pushing; and (d) when the pusher box is in the back-drag position, back-dragging material received in the material collection space with the working face during reverse operation of the machine, with the sidewalls positioned to laterally retain the material in the material collection space during the back-dragging.DRAWINGS

[0024] For a better understanding of the described examples and to show more clearly how they may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

[0025] FIG. 1 is a front perspective view of an example pusher box attachment in a pusher configuration;

[0026] FIG. 2 is a side elevation schematic showing the attachment of FIG. 1 mounted to an example vehicle and used in a pusher mode;

[0027] FIG. 3 is a front perspective view of the attachment of FIG. 1, but showing the attachment in a back-drag configuration;

[0028] FIG. 4 is a side elevation schematic showing the attachment of FIG. 3 mounted to the vehicle and used in a back-drag mode;

[0029] FIG. 5 is a rear perspective view of the attachment of FIG. 1;

[0030] FIG. 6 is a rear perspective view of the attachment of FIG. 3;

[0031] FIG. 7 is a side elevation view of the attachment of FIG. 1;

[0032] FIG. 8 is a side elevation view of the attachment of FIG. 3;

[0033] FIG. 9 is a cross-sectional view of the attachment of FIG. 1, taken along line 9-9 in FIG. 5; and

[0034] FIG. 10 is another side elevation view of the attachment of FIG. 1, but showing a trip mechanism of the attachment activated.DESCRIPTION OF VARIOUS EXAMPLES

[0035] Various apparatuses, systems, or processes will be described below to provide an example of each claimed invention. No example described below limits any claimed invention and any claimed invention may cover processes, systems, or apparatuses that differ from those described below. The claimed inventions are not limited to apparatuses, systems, or processes having all of the features of any one apparatus, system, or process described below or to features common to multiple or all of the apparatuses, systems, or processes described below. It is possible that an apparatus, system, or process described below is not an example of any claimed invention. Any invention disclosed in an apparatus, system, or process described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors, or owners do not intend to abandon, disclaim, or dedicate to the public any such invention by its disclosure in this document.

[0036] Moving particulate material (e.g. snow, soil, gravel, etc.) can involve mounting a blade to a powered material-handling machine (e.g., mini-skid loaders, full-size skid loaders, tractors with a front-end loader, compact wheel loaders, full-size wheel loaders, backhoe loaders, telehandlers, other vehicles, etc.) and pushing the material forward with the blade during forward operation of the machine (e.g. by operating a vehicle forward or advancing a boom or arm of the vehicle forward). In some situations, some of the material may lie adjacent a structure (e.g. wall, garage door, etc.) in the area being cleared of the material, and the machine may be unable to effectively operate parallel to the structure to push the adjacent material. In such situations, it can be desirable to back drag the material away from the structure with the blade by pulling the blade during reverse operation of the machine (e.g. by operating the vehicle in reverse or retracting a boom or arm of the vehicle).

[0037] Some existing material handling systems capable of switching between pushing and back dragging modes can be overly complex and costly. Some can also suffer from notable disadvantages for the pusher and / or back-dragging mode. These disadvantages can include, for example, requiring use of a rear surface of the blade that lacks preferred curvature for material movement, the inability to stop material from easily spilling out from the sides, and / or requiring the operator to exit the vehicle to switch modes.

[0038] According to some aspects of the present disclosure, a dual-mode material-handling attachment is disclosed that can help address some of the shortcomings of existing material handling systems, and / or provide for reduced cost and complexity relative to some existing systems. The material-handling attachment of the present disclosure can be in the form of a pusher box attachment having a frame detachably mountable to the vehicle and pivotably supporting a pusher box. The pusher box is pivotable relative to the frame between a pusher position and a back-drag position. The pusher box is pivotable to the pusher position for operating the attachment in a pusher mode, in which a first cutting edge of the pusher box is positioned for engagement with a substrate surface (e.g. ground surface or material layer) beneath the attachment for pushing material along the substrate surface with a working face of the pusher box facing generally forward during forward operation of the machine. The pusher box is pivotable to the back-drag position for operating the attachment in a back-drag mode, in which an opposite second cutting edge of the pusher box is positioned for engagement with the substrate surface for back-dragging material along the substrate surface with the working face of the pusher box facing generally rearward during reverse operation of the machine. The pusher box has a pair of side plates fixed relative to and projecting from the working face. The pair of side plates laterally enclose a material collection space adjacent the working face, and laterally retain material in the material collection space when operating the attachment in both the pusher mode as well as in the back-drag mode.

[0039] Referring to FIGS. 1 and 2, an example of a dual-mode pusher box attachment 100 for a powered material-handling machine 10 is illustrated. The attachment 100 includes a frame 102 having a frame axis 104 between a rear 106 and a front 108 of the frame 102. The frame 102 includes a mounting portion 110 at the rear 106 for detachably mounting the attachment 100 to the machine 10. In the example illustrated, the frame 102 further includes a support portion 112 projecting along the frame axis 104 from the mounting portion 110 to the front 108 of the frame 102. In the example illustrated, the support portion 112 comprises a pair of arms 114 spaced laterally apart from each other and projecting along the frame axis 104 from the mounting portion 110 to the front 108 of the frame 102.

[0040] In the example illustrated, the attachment 100 includes a pusher box 116 pivotably supported by the support portion 112. In the example illustrated, the pusher box 116 is laterally between and pivotably mounted to the pair of arms 114 for pivoting about a lateral pivot axis 118 relative to the frame 102 between a pusher position (shown in FIGS. 1 and 2) and a back-drag position (shown in FIGS. 3 and 4). The lateral pivot axis 118 is oriented perpendicular to the frame axis 104. The pusher box 116 includes a blade wall 120 having a working face 122 for material engagement. In the example illustrated, the working face 122 extends vertically between a bottom cutting edge 124 and a top cutting edge 126 opposite the bottom cutting edge 124. The bottom and top cutting edges 124, 126 are fixed relative to the working face 122 and oriented parallel to the lateral pivot axis 118. In the example illustrated, the bottom and top cutting edges 124, 126 comprise respective cutting blades removably mounted to the pusher box 116 (e.g. to facilitate replacement thereof when worn).

[0041] In the example illustrated, the working face 122 extends laterally between a pair of sidewalls 128 of the pusher box 116. The pair of sidewalls 128 are fixed relative to and project from the working face 122. The sidewalls 128 have respective inboard surfaces 130 directed toward each other for laterally enclosing a material collection space 132 adjacent the working face 122. In the example illustrated, each inboard surface 130 extends vertically along the working face 122 between opposed first and second sidewall edges 134, 136 of a respective sidewall 128. The first sidewall edge 134 projects from the working face 122 adjacent the bottom cutting edge 124. The second sidewall edge 136 projects from the working face 122 adjacent the top cutting edge 126. In the example illustrated, each inboard surface 130 projects from the working face 122 to a distal edge 138 of the sidewall 128 spaced apart from the working face 122. The first sidewall edge 134 extends generally linearly from the working face 122 to a lower end of the distal edge 138, and the second sidewall edge 136 extend generally linearly from the working face 122 to an upper end of the distal edge 138.

[0042] Still referring to FIGS. 1 and 2, when in the pusher position, the pusher box 116 is oriented generally upright. The working face 122 of the blade wall 120 faces generally forward away from the machine 10 (and mounting portion 110 of the frame 102) for pushing material 11 received in the material collection space 132 forwardly along a substrate surface 12 below the attachment 100. The bottom cutting edge 124 is at an elevation below the top cutting edge 126 and adjacent the substrate surface 12 for material engagement to facilitate the pushing. The first sidewall edges 134 of the sidewalls 128 are adjacent and generally parallel with the substrate surface 12 to inhibit material from spilling laterally from the material collection space 132 during the pushing.

[0043] Referring to FIGS. 3 and 4, when in the back-drag position, the pusher box 116 is pivoted about the pivot axis 118 relative to the pusher position. In the example illustrated, when in the back-drag position, the pusher box 116 is generally inverted relative to the upright pusher position. In the back-drag position, the working face 122 (FIG. 6) of the blade wall 120 faces rearward toward the machine 10 (and mounting portion 110 of the frame 102) for back-dragging material 11 received in the material collection space 132 (FIG. 6) rearwardly along the substrate surface 12, and away from, for example, an adjacent structure 14 such as a building wall or garage door. The top cutting edge 126 is at an elevation below the bottom cutting edge 124 and adjacent the substrate surface 12 for material engagement to facilitate the back-dragging. The second sidewall edges 136 of the sidewalls 128 are adjacent and generally parallel with the substrate surface 12 to inhibit material from spilling laterally out from the material collection space 132 (FIG. 6) during the back-dragging.

[0044] Referring to FIG. 5, in the example illustrated, each first sidewall edge 134 comprises a respective first skid shoe 140 for sliding engagement with the substrate surface when the pusher box 116 is in the pusher position. In the example illustrated, each second sidewall edge 136 comprises a second skid shoe 142 for sliding engagement with the substrate surface when the pusher box 116 is in the back-drag position. In the example illustrated, each sidewall 128 comprises a sidewall plate 144 and each of the first and second skid shoes 140, 142 are mounted to the sidewall plate 144. In the example illustrated, the first skid shoe 140 is securable to the sidewall plate 144 in any one of a plurality of heights relative to the bottom cutting edge 124 in the pusher position, to permit selective raising and lowering of the first sidewall edge 134 relative to the bottom cutting edge 124 for adjusting cutting action of the bottom cutting edge 124.

[0045] In the example illustrated, the pair of sidewalls 128 are pivotably supported by respective arms 114 of the frame 102 for pivoting of the pusher box 116 about the pivot axis 118, with the pivot axis 118 intersecting the pair of sidewalls 128 and fixed relative to the frame 102. In the example illustrated, the pair of sidewalls 128 have respective outboard surfaces 146 laterally opposite the inboard surfaces 130. A pair of pivot pins 147 are fixed relative to and project laterally outwardly from the outboard surfaces 146 of respective sidewalls 128 coaxial with the pivot axis 118. The pair of pivot pins 147 are pivotably supported by respective arms 114 of the frame 102.

[0046] Referring to FIGS. 7 and 8, in the example illustrated, the pivot axis 118 is vertically intermediate the bottom and top cutting edges 124, 126 in the pusher position (FIG. 6) and in the back-drag position (FIG. 7). Referring to FIG. 7, in the pusher position, the bottom cutting edge 124 is at an elevation below and rearward of the pivot axis 118, and the top cutting edge 126 is at an elevation above and forward of the pivot axis 118. The pusher box 116 pivots about the pivot axis 118 from the pusher position toward the back-drag position in a first circumferential direction 143. When the pusher box 116 is pivoted from the pusher position toward the back-drag position in the first circumferential direction 143, the bottom cutting edge 124 initially swings rearward and upwardly about the lateral pivot axis, and the top cutting 126 edge initially swings forward and downwardly about the pivot axis 118.

[0047] Referring to FIG. 8, in the back-drag position, the top cutting edge 126 is at an elevation below and forward of the pivot axis 118 and the bottom cutting edge 124 is at an elevation above and rearward of the pivot axis 118. In the example illustrated, the pusher box 116 pivots about the pivot axis 118 from the back-drag position to the pusher position in a second circumferential direction 145 opposite the first circumferential direction 143. When the pusher box 116 is pivoted from the back-drag position toward the pusher position in the second circumferential direction, the top cutting edge 126 initially swings forward and upwardly about the pivot axis 118, and the bottom cutting edge 124 initially swings rearward and downwardly about the pivot axis 118.

[0048] Referring to FIG. 7, in the example illustrated, the pusher box 116 has a pair of stops 148 fixed relative to and projecting laterally outwardly from respective outboard surfaces 146 of the sidewalls 128. The pair of stops 148 are positioned for engagement with respective abutment surfaces 150 fixed relative to the pair of arms 114 of the frame 102, to limit pivoting of the pusher box 116 in the first circumferential direction 143 past the back-drag position. In the example illustrated, the pair of stops 148 are spaced transversely apart from the pivot axis 118. The pair of stops 148 are spaced circumferentially apart from respective abutment surfaces 150 when the pusher box 116 is in the pusher position (FIG. 7), and the stops 148 are brought into engagement with respective abutment surfaces 150 when the pusher box 116 is moved into the back-drag position (FIG. 8).

[0049] Referring to FIG. 1, in the example illustrated, the pusher box 116 includes a cross-brace 152 extending laterally through the material collection space 132 between the inboard surfaces 130 of the sidewalls 128 for rigidly coupling the sidewalls 128 to each other, which can help inhibit deflection and increase structural rigidity of the sidewalls 128. In the example illustrated, the cross-brace 152 is spaced apart from the working face 122 and positioned toward the distal edges 138 of the sidewalls 128. The cross-brace 152 is vertically intermediate and spaced apart from the first and second sidewall edges 134, 136 of the sidewalls 128 to provide vertical clearance between the substrate surface and the cross-brace 152 for receiving material in the material collection space 132 when the pusher box 116 is in the pusher position and the back-drag position. In the example illustrated, each sidewall 128 is further reinforced by a respective gusset 154 in the material collection space 132 at the intersection between the inboard surface 130 of the sidewall 128 and the working face 122 of the blade wall 120.

[0050] Referring to FIG. 5, in the example illustrated, the blade wall 120 has a window 156 for visibility of the material collection space 132 through the blade wall 120 by an operator of the machine when the pusher box 116 is in the pusher position. When the pusher box 116 is in the pusher position, the window 156 is positioned to provide the operator of the machine 10 with a generally unobstructed sightline 16 (FIG. 2) through the window 156 from within a cab 18 (FIG. 2) of the machine 10 during operation of the attachment 100 in the pusher position. In the example illustrated, the blade wall 120 has an upper panel portion 158 at an elevation above the pivot axis 118 when the pusher box 116 is in the pusher position, and the window 156 is on the upper panel portion 158. In the example illustrated, the window 156 comprises one or more window openings 160 in the upper panel portion 158 of the blade wall 120. In the example illustrated, the window 156 comprises a plurality of window openings 160 spaced laterally apart from each other. The window 156 has at least one transparent window panel 162 covering the window openings 160. The at least one transparent window panel 162 can be formed of an impact-resistant material (e.g. polycarbonate). The at least one window panel 162 can be detachably mounted to the upper panel portion 158 to facilitate replacement thereof.

[0051] Referring to FIG. 9, in the example illustrated, in the pusher position, the working face 122 of the blade wall 120 has a lower portion 164 extending rearwardly and upwardly from the bottom cutting edge 124. The lower portion 164 cooperates with an upper portion 166 of the working face 122 that slopes forwardly from the lower portion 164 to the top cutting edge 126 to approximate the profile of a curved moldboard for pushing the material. In the example illustrated, the lower portion 164 of the working face 122 projects downwardly to an elevation below the pivot axis 118 (FIG. 7) and the pair of arms 114 of the frame 102, and the upper portion 166 is at an elevation above the pivot axis 118 (FIG. 7) and the pair of arms 114 of the frame 102.

[0052] Referring to FIG. 6, in the example illustrated, the mounting portion 110 of the frame 102 has a mount 168 (e.g. a quick-attach mount plate) at the rear 106 of the frame 102 for attachment to the machine. In the example illustrated, the mount 168 is fixed relative to the pair of arms 114 of the frame 102 and configured to interface with a complementary coupler 20 (FIG. 2) of the machine 10 (e.g. a skid steer quick-attach mechanism). In some examples, the mount 168 can optionally have an adjustable height for accommodating various couplers of different machines.

[0053] In the example illustrated, the attachment 100 includes an actuator system having at least one actuator assembly 170 for pivoting the pusher box 116 between the pusher and back-drag positions. In the example illustrated, the actuator system includes a pair of actuator assemblies 170, one on each side of the attachment 100 laterally outboard of the pusher box 116. In the example illustrated, the pair of actuator assemblies 170 couple respective sidewalls 128 of the pusher box 116 to respective arms 114 of the frame 102. Each actuator assembly 170 is generally in lateral alignment with a respective arm 114 of the frame 102.

[0054] Referring to FIG. 7, in the example illustrated, each actuator assembly 170 has at least one actuator 172 energizable to urge pivoting of the pusher box 116 between the pusher and back-drag positions. In the example illustrated, each actuator 172 comprises a linear actuator in the form of a hydraulic cylinder 174. Referring to FIG. 8, each hydraulic cylinder 174 has a rod 176 slidable in a cylinder housing 178. The hydraulic cylinder 174 comprises a double-acting hydraulic cylinder energizable to slide the rod 176 between a first position (FIG. 7) corresponding to the pusher position and a second position (FIG. 8) corresponding to the back-drag position. Referring to FIG. 7, in the example illustrated, the rod 176 is retracted into the cylinder housing 178 when moved into the first position to pivot the pusher box 116 to the pusher position. Referring to FIG. 8, when moved into the second position, the rod 176 is extended from the cylinder housing 178 relative to the first position to pivot the pusher box 116 to the back-drag position. In the example illustrated, the cylinder housing 178 has a cap end 180 pivotably coupled to the frame 102, and the rod 176 has a rod end 182 pivotably coupled to the pusher box 116. The rod end 182 is pivotably coupled to the pusher box 116 at a pivot joint spaced transversely apart from the lateral pivot axis 118 and attached to the stop 148 projecting from a respective sidewall 128 of the pusher box 116.

[0055] Referring to FIG. 10, in the example illustrated, the attachment 100 includes a trip system permitting limited pivoting of the pusher box 116 from the pusher position toward the back-drag position, to accommodate swinging of the bottom cutting edge 124 rearwardly and upwardly upon impact with an obstacle on the substrate surface, and urging the pusher box 116 back toward the pusher position when the obstacle is cleared.

[0056] In the example illustrated, the trip system comprises one or more spring-loaded trip mechanisms 186 having at least one return spring 188. When the pusher box 116 is in the pusher position, the at least one return spring 188 biases the pusher box 116 to the pusher position and permits limited pivoting of the pusher box 116 from the pusher position toward the back-drag position. In the example illustrated, the trip system includes a pair of spring-loaded trip mechanisms 186 integrated with respective actuator assemblies 170. In the example illustrated, the cap end 180 of each hydraulic cylinder 174 is coupled to the frame 102 through a respective spring-loaded trip mechanism 186. In the example illustrated, the spring-loaded trip mechanism 186 and respective actuator 172 are operable independently. The return spring 188 of each spring-loaded trip mechanism 186 is coupled to a respective cap end 180 through a linkage 190 configured to permit the rod 176 of each hydraulic cylinder 174 to remain in the first (retracted) position (corresponding to the pusher position) during activation of the trip mechanism.

[0057] In the example illustrated, portions of a hydraulic coupling assembly 192 are shown schematically in FIG. 10 for fluidly connecting the hydraulic cylinders 174 to the hydraulic system of the machine 10 through hydraulic lines. In some examples, the trip system can alternatively or in addition include an optional hydraulic accumulator 194 integrated with the hydraulic coupling assembly 192. The hydraulic accumulator 194 can be configured to permit limited sliding of the rod 176 from the first (retracted) position toward the second (extended) position in response to hydraulic pressure exceeding a threshold activation pressure of the hydraulic accumulator 194, thereby permitting limited pivoting of the pusher box 116 from the pusher position toward the back-drag position upon impact with an obstacle on the substrate surface, and return of the pusher box 116 back to the pusher position when the obstacle is cleared.

[0058] Referring to FIGS. 3 and 4, in the example illustrated, the pusher box 116 includes a pair of marker poles 196 on laterally opposite sides of the pusher box 116. When the pusher box 116 is in the back-drag position, the marker poles 196 project upwardly from the pusher box 116 at the front of the attachment 100 to serve as visual indicators of the position of the front and sides of the attachment 100. During back-dragging, the marker poles 196 can assist the operator in positioning the pusher box 116 in the back-drag position relative to an obstacle (e.g. structure 14 in FIG. 4) and determining clearance during operation (e.g. to avoid contacting or damaging structures in the operating area being cleared during a back-drag operation).

Claims

1. A dual-mode pusher box attachment for a powered material-handling machine, comprising:a) a frame having a frame axis between a rear and a front of the frame, the frame including a mounting portion at the rear for detachably mounting the attachment to the machine, and a pair of arms spaced laterally apart from each other and projecting along the frame axis from the mounting portion to the front of the frame; andb) a pusher box laterally between and pivotably mounted to the pair of arms for pivoting about a lateral pivot axis relative to the frame between an upright pusher position and a pivoted back-drag position, the pusher box including a blade wall having a working face extending vertically between opposed top and bottom cutting edges fixed relative to the working face and oriented parallel to the lateral pivot axis, and the working face extending laterally between a pair of sidewalls fixed relative to and projecting from the working face, the sidewalls having respective inboard surfaces directed toward each other for laterally enclosing a material collection space adjacent the working face, each inboard surface extending vertically along the working face between opposed first and second sidewall edges of the sidewall, the first and second sidewall edges projecting from the working face adjacent respective first and second cutting edges,c) when the pusher box is in the pusher position, the working face of the blade wall faces generally forward away from the machine for pushing material received in the material collection space forwardly along a substrate surface below the attachment, with the bottom cutting edge at an elevation below the top cutting edge and adjacent the substrate surface for material engagement to facilitate the pushing, and the first sidewall edge of the sidewalls adjacent and generally parallel with the substrate surface to inhibit material from spilling laterally from the material collection space during the pushing, andd) when the pusher box is in the back-drag position, the working face of the blade wall faces generally rearward toward the machine for back-dragging material received in the material collection space rearwardly along the substrate surface, with the top cutting edge at an elevation below the bottom cutting edge and adjacent the substrate surface for material engagement to facilitate the back-dragging, and the second sidewall edge of the sidewalls adjacent and generally parallel with the substrate surface to inhibit material from spilling laterally out from the material collection space during the back-dragging.

2. The attachment of claim 1, wherein each first sidewall edge comprises a respective first skid shoe for sliding engagement with the substrate surface when the pusher box is in the pusher position.

3. The attachment of claim 2, wherein each second sidewall edge comprises a second skid shoe for sliding engagement with the substrate surface when the pusher box is in the back-drag position.

4. The attachment of claim 1, wherein the pair of sidewalls are pivotably supported by respective arms of the frame for pivoting of the pusher box about the pivot axis, the pivot axis intersecting the sidewalls and fixed relative to the frame.

5. The attachment of claim 1, further comprising one or more actuators coupled between the pusher box and the frame, the one or more actuators energizable to urge pivoting of the pusher box between the pusher position and the back-drag position.

6. The attachment of claim 5, wherein the attachment includes a pair of the actuators coupled between respective sidewalls of the pusher box and the frame.

7. The attachment of claim 5, further comprising an integrated trip system permitting limited pivoting of the pusher box from the pusher position toward the back-drag position to accommodate swinging of the bottom cutting edge rearwardly and upwardly upon impact with an obstacle on the substrate surface, and urging the pusher box back toward the pusher position when the obstacle is cleared.

8. The attachment of claim 7, wherein the trip system comprises one or more spring-loaded trip mechanisms coupled between the pusher box and the frame.

9. The attachment of claim 8, wherein the one or more spring-loaded trip mechanisms are operable independent of the one or more actuators.

10. The attachment of claim 7, wherein each actuator comprises a hydraulic cylinder having a rod slidable in a cylinder housing between a first position corresponding to the pusher position and a second position corresponding to the back-drag position.

11. The attachment of claim 10, further comprising a hydraulic coupling assembly for fluidly connecting the hydraulic cylinder to a hydraulic system of the machine, and the trip system comprises a hydraulic accumulator integrated with the hydraulic coupling assembly, the hydraulic accumulator permitting limited movement of the rod from the first position toward the second position in response to hydraulic pressure exceeding a threshold activation pressure of the hydraulic accumulator.

12. The attachment of claim 1, wherein the blade wall has a window for visibility of the material collection space through the blade wall by an operator of the machine when operating the pusher box in the pusher position.

13. The attachment of claim 1, wherein the pusher box has a pair of stops fixed relative to and projecting laterally outwardly from respective outboard surfaces of the sidewalls, the pair of stops positioned for engagement with respective abutment surfaces fixed relative to the pair of arms of the frame to limit pivoting of the pusher box past the back-drag position.

14. The attachment of claim 1, wherein the frame is spaced vertically above the substrate surface when the attachment is mounted to the vehicle.

15. A dual-mode pusher box attachment for a powered material-handling machine, comprising:a) a frame detachably mountable to the machine;b) a pusher box pivotably mounted to the frame for pivoting about a lateral pivot axis relative to the frame between a first position and a second position, the pusher box including a blade wall having a working face extending vertically between opposed first and second cutting edges of the blade wall, and laterally between a pair of sidewalls fixed relative to and projecting from the working face for laterally enclosing a material collection space adjacent the working face, andc) when the pusher box is in the first position, the working face of the blade wall faces generally forward away from the machine for pushing material received in the material collection space along a substrate surface, with the first cutting edge at an elevation below the second cutting edge and adjacent the substrate surface for material engagement, and the sidewalls adjacent the substrate surface to inhibit material from spilling laterally from the material collection space during the pushing, andd) when the pusher box is in the second position, the working face of the blade wall faces generally rearward toward the machine for back-dragging material received in the material collection space, with the second cutting edge at an elevation below the first cutting edge and adjacent the substrate surface for material engagement.

16. The attachment of claim 15, wherein when the pusher box is in the second position, the sidewalls are positionable adjacent the substrate surface to inhibit material from spilling laterally out from the material collection space during the back-dragging.

17. The attachment of claim 15, wherein each sidewall has a first skid shoe for sliding engagement with the substrate surface when the pusher box is in the first position, and a second skid shoe spaced apart from the first skid shoe for sliding engagement with the substrate surface when the pusher box is in the second position.

18. The attachment of claim 15, further comprising a pair of actuators coupled between respective sidewalls of the pusher box and the frame, the pair of actuators energizable to urge pivoting of the pusher box between the pusher and back-drag positions.

19. The attachment of claim 15, wherein the frame has a pair of arms spaced laterally apart from each other and projecting forward from the mounting portion, and the pusher box is laterally between and pivotably mounted to the pair of arms.

20. A method of moving material, comprising:a) mounting a frame of a pusher box attachment to a powered material-handling machine, the frame pivotably supporting a pusher box of the attachment;b) pivoting the pusher box relative to the frame about a lateral pivot axis between a pusher position and a back-drag position, and when the pusher box is in the pusher position, a working face of the pusher box faces generally forward away from the machine with a pair of sidewalls of the pusher box projecting from the working face to laterally enclose a material collection space adjacent the working face, and when the pusher box is in the back-drag position, the working face of the pusher box faces generally rearward toward the machine;c) when the pusher box is in the pusher position, pushing material received in the material collection space of the pusher box with the working face during forward operation of the machine, with the sidewalls positioned to laterally retain the material in the material collection space during the pushing; andd) when the pusher box is in the back-drag position, back-dragging material received in the material collection space with the working face during reverse operation of the machine, with the sidewalls positioned to laterally retain the material in the material collection space during the back-dragging.

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