# US 2021/0274711 A1 · Rotary mower with cutting deck with bidirectional cutting blades > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0274711 A1 - Document ID: US20210274711A1 - Status: Published application - Kind: A1 - Application number: 17/195,113 - Filed: 2021-03-08 - Published: 2021-09-09 - Earliest claimed: 2020-03-09 - Assignees: The Toro Company - Applicants: The Toro Company - Inventors: Jason J. Henry; Chris A. Wadzinski - Web page: https://patentgrep.com/patent/US20210274711A1 ## CPC - A01D 42/005: {Mulching (shredders or like cutting implements for comminuting plant waste per se A01G3/002)} - A01D 34/667: {Means for directing the cut crop} - A01D 34/71: with means for discharging mown material (A01D57/26 - A01D57/30 take precedence; combined with means for gathering or loading mown material A01D43/06) - A01D 34/73: Cutting apparatus - A01D 34/76: Driving mechanisms for the cutters - A01D 34/81: Casings; Housings (A01D34/71 takes precedence) - A01D: HARVESTING; MOWING ## Abstract A rotary lawn mower has one or more grass cutting blades that are rotatable in opposite directions about a vertical axis or axes. Each blade is double edged having front and rear cutting edges on each end of the blade. Each blade end has a front sloped face inboard of the front cutting edge and a rear sloped face inboard of the rear cutting edge. These faces create air flow within the cutting chamber when cutting grass regardless of the direction of rotation of the blade. The direction of rotation of each blade is reversed to switch between discharge and mulching modes of operation. A flow director has a curved vertical guide wall that guides the grass clippings through a discharge opening in the discharge mode and that guides the flow of grass clippings away from the discharge opening in the mulching mode. ## Claims ### Claim 1 A rotary lawn mower, which comprises: (a) a cutting deck comprising a top wall and a peripheral skirt extending downwardly from the top wall, the top wall and peripheral skirt forming a cutting chamber having an open bottom face, the cutting chamber having a discharge opening located at least partially in the peripheral skirt of the deck for allowing grass clippings to exit from the cutting chamber; (b) at least one cutting blade located within the cutting chamber with the at least one blade being rotatable about a substantially vertical axis of rotation, each end of the at least one blade comprising: (i) a front cutting edge and a rear cutting edge, and (ii) an upwardly raised, front sloped face inboard of the front cutting edge and an upwardly raised, rear sloped face inboard of the rear cutting edge; and (c) a reversible blade drive for allowing a user to select either: (i) a discharge mode of operation in which the at least one blade rotates in a first direction about the axis of rotation with the front cutting edges being leading edges and the rear cutting edges being trailing edges, or (ii) a mulching mode of operation in which the at least one blade rotates in a second opposite direction about the axis of rotation with the rear cutting edges being leading edges and the front cutting edges being trailing edges. ### Claim 2 (depends on 1) The mower of claim 1, wherein each end of the at least one blade comprises at least one opening extending through a thickness of the at least one blade to permit the passage of air through the at least one opening, wherein the at least one opening in each end of the blade is located between the front and rear cutting edges on each end of the blade. ### Claim 3 (depends on 2) The mower of claim 2, wherein the at least one opening comprises a radial slot. ### Claim 4 (depends on 3) The mower of claim 3, wherein the front and rear sloped faces on each end of the at least one blade are inboard of the front and rear cutting edges. ### Claim 5 (depends on 2) The mower of claim 2, wherein the front and rear sloped faces have substantially the same angle of inclination as one another. ### Claim 6 (depends on 2) The mower of claim 2, wherein the front and rear sloped faces have a substantially constant height relative to the front and rear cutting edges. ### Claim 7 (depends on 1) The mower of claim 1, wherein the front sloped face has an inclination of at least approximately 60° at a tip of each end of the at least one blade. ### Claim 8 (depends on 1) The mower of claim 1, wherein the front sloped face is steeper than the rear sloped face. ### Claim 9 (depends on 8) The mower of claim 8, wherein the front sloped face is at least approximately three times steeper than the rear sloped face at a tip of each end of the at least one blade. ### Claim 10 (depends on 9) The mower of claim 9, further including a raised ridge on each end of the at least one blade located between the front and rear cutting edges, wherein the front sloped face is formed by a surface extending between the front cutting edge of the at least one blade and a crest of the ridge and the rear sloped face is formed by a surface extending between the rear cutting edge of the at least one blade and the crest of the ridge. ### Claim 11 (depends on 10) The mower of claim 10, wherein the ridge gradually decreases in height relative to the cutting edges as the ridge extends radially inwardly from the tip of each end of the at least one blade. ### Claim 12 (depends on 11) The mower of claim 11, wherein the ridge disappears at radial inner ends of the cutting edges. ### Claim 13 (depends on 1) The mower of claim 1, wherein the at least one blade comprises two or more blades with each blade being rotatable about its own separate substantially vertical axis of rotation. ### Claim 14 (depends on 1) The mower of claim 1, wherein the cutting chamber has a substantially vertical, curved guide wall therein adjacent the discharge opening, the guide wall presenting an outward curvature to grass clippings that have been generated in the discharge mode to direct such clippings outwardly through the discharge opening, and the guide wall further presenting an inward curvature to grass clippings that have been generated in the mulching mode to direct such clippings inwardly in the cutting chamber away from the discharge opening. ### Claim 15 (depends on 14) The mower of claim 14, wherein the cutting chamber has a substantially horizontal floor along a bottom edge of the curved guide wall extending between the curved guide wall and the peripheral wall of the cutting chamber. ### Claim 16 (depends on 14) The mower of claim 14, wherein the guide wall and the floor are formed as part of a single piece flow director that is separate from the cutting deck, and further including fasteners for removably mounting the flow director to the cutting deck adjacent the discharge opening. ### Claim 17 A rotary lawn mower, which comprises: (a) a cutting deck comprising a top wall and a peripheral skirt extending downwardly from the top wall, the top wall and peripheral skirt forming a cutting chamber having an open bottom face, the cutting chamber having a discharge opening located at least partially in the peripheral skirt of the deck for allowing grass clippings to exit from the cutting chamber; (b) at least one cutting blade located within the cutting chamber with the at least one blade being rotatable about a substantially vertical axis of rotation, each end of the at least one blade comprising a front cutting edge and a rear cutting edge; (c) a reversible blade drive for allowing a user to select either: (i) a discharge mode of operation in which the at least one blade rotates in a first direction about the axis of rotation with the front cutting edges being leading edges and the rear cutting edges being trailing edges, or (ii) a mulching mode of operation in which the at least one blade rotates in a second opposite direction about the axis of rotation with the rear cutting edges being leading edges and the front cutting edges being trailing edges; and (d) wherein the cutting chamber has a substantially vertical guide wall therein adjacent the discharge opening, the guide wall presenting an outward side to grass clippings that have been generated in the discharge mode to direct such clippings outwardly through the discharge opening, and the guide wall further presenting an inward side to grass clippings that have been generated in the mulching mode to direct such clippings inwardly in the cutting chamber away from the discharge opening. ### Claim 18 (depends on 17) The mower of claim 17, wherein the cutting chamber has a substantially horizontal floor along a bottom edge of the guide wall extending between the guide wall and the peripheral wall of the cutting chamber. ### Claim 19 (depends on 18) The mower of claim 18, wherein the guide wall and the floor are formed as part of a single piece flow director that is separate from the cutting deck, and further including fasteners for removably mounting the flow director to the cutting deck adjacent the discharge opening. ### Claim 20 (depends on 17) The mower of claim 17, wherein the at least one blade comprises two or more blades mounted within the cutting chamber with each blade being rotatable about its own separate substantially vertical axis of rotation.