Low speed rotary mower
First Claim
1. Rotary mowing and bagging apparatus, comprising, in combination:
- (a) a cutting blade mounted for rotation about a substantially vertical axis, said blade having a pair of cutting tips at opposite ends thereof, with each tip having a body including a leading cutting edge and a trailing sail portion having a front surface thereon, each of said front surfaces being substantially inwardly raked at an angle substantially in the range of ten degrees (10°
) to sixty degrees (60°
) with respect to the blade center line measured in the plane of rotation, said front surfaces being substantially upwardly raked at an upward rake angle substantially in the range of fifteen degrees (15°
) to fifty degrees (50°
), said upward rake angle being defined as the angle between said front surface and a line perpendicular to the body of said tips;
(b) a mower housing in which said blade is mounted, having an expansion portion with an expansion top wall with a substantial rise therein leading to a discharge opening, said housing also having a continuous exterior side wall surrounding said blade at the height thereof and extending above said cutting portions;
(c) means for rotatably driving said blade at a predetermined tip speed below 14,000 FPM, yet sufficient to cause the cutting edges of said blade to cleanly cut blades of grass, clear cut grass particles from the edges, and to impart sufficient momentum to the cut grass particles to allow collection thereof;
(d) front and rear wheels mounted on said housing to enable movement of said mower over a ground surface at a controlled height thereabove; and
(e) a grass-catching bag attached to said housing at said discharge opening.
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Accused Products
Abstract
A rotary mower in which grass cutting and collection of cut grass particles is achieved with a relatively low blade tip speed. A cutting blade is mounted for rotation about a vertical axis within a symmetrical expansion type mower housing in which the expansion top wall has a substantial rise to a discharge opening vertically above the cutting blade. The housing has a continuous exterior side wall surrounding the cutting blades and extending above the sail portion thereof. The sail portions of the blade trailing the cutting edges have substantial inward and upward rake angles which result in mechanical throwing of the grass and a pumping effect results from the housing and blade configuration. In certain embodiments, the cutting edges may be swept back at an angle with respect to the blade center line and the blade diameter may be selected to aid in effective cleaning of cut grass particles from the blade.
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Citations
17 Claims
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1. Rotary mowing and bagging apparatus, comprising, in combination:
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(a) a cutting blade mounted for rotation about a substantially vertical axis, said blade having a pair of cutting tips at opposite ends thereof, with each tip having a body including a leading cutting edge and a trailing sail portion having a front surface thereon, each of said front surfaces being substantially inwardly raked at an angle substantially in the range of ten degrees (10°
) to sixty degrees (60°
) with respect to the blade center line measured in the plane of rotation, said front surfaces being substantially upwardly raked at an upward rake angle substantially in the range of fifteen degrees (15°
) to fifty degrees (50°
), said upward rake angle being defined as the angle between said front surface and a line perpendicular to the body of said tips;(b) a mower housing in which said blade is mounted, having an expansion portion with an expansion top wall with a substantial rise therein leading to a discharge opening, said housing also having a continuous exterior side wall surrounding said blade at the height thereof and extending above said cutting portions; (c) means for rotatably driving said blade at a predetermined tip speed below 14,000 FPM, yet sufficient to cause the cutting edges of said blade to cleanly cut blades of grass, clear cut grass particles from the edges, and to impart sufficient momentum to the cut grass particles to allow collection thereof; (d) front and rear wheels mounted on said housing to enable movement of said mower over a ground surface at a controlled height thereabove; and (e) a grass-catching bag attached to said housing at said discharge opening. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. In combination with a rotary lawn mower:
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(a) a mower housing having a cutting region thereof with a continuous closed vertical side wall, and a transport and discharge region spaced above said cutting region and defining a channel extending circumferentially about said housing, said channel having a top wall of progressively increasing height generally defining a circular helix in form and terminating at a discharge opening in said housing, said discharge opening being positioned entirely vertically above said cutting region; (b) a cutting blade mounted for rotation about a nearly vertical axis within said cutting region, said blade having a pair of leading cutting edges thereon; (c) mechanical throwing means defining impact surfaces trailing said cutting edges and rotating therewith to impact grass particles severed by said edges and direct said particles inward and upward into said transport and discharge region, said impact surfaces being located entirely within said cutting region and having substantial upward rake less than a right angle to the cutting plane defined by rotation of said cutting edges about said axis, also having substantial inward rake; (d) means rotatably driving said blade at a tip speed less than 14,000 FPM, yet sufficient to cause the cutting edges of said blade to cleanly cut blades of grass, clear cut grass particles from the edges, and to impart sufficient momentum to the cut grass particles to allow collection thereof; and (e) pumping means rotating with said blade and combining with said vertical side wall for drawing air inwardly around the bottom edge thereof and pumping said air circumferentially and axially to said discharge opening by means of said channel to aid in transport of said particles. - View Dependent Claims (11, 12, 13, 14)
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15. Rotary mowing and bagging apparatus, comprising, in combination:
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(a) a cutting blade mounted for rotation about a substantially vertical axis, said blade having a pair of cutting tips at opposite ends thereof, with each tip having a body including a leading cutting edge and a trailing sail portion having a front surface thereon, each of said front surfaces being substantially inwardly raked, said front surfaces each having substantial upward rake less than a right angle to the cutting plane defined by rotation of said cutting edges about said axis, said upward rake angle being defined as the angle between said front surface and a line perpendicular to the body of said tips; (b) a mower housing in which said blade is mounted, having an expansion portion with an expansion top wall with a substantial rise therein leading to a discharge opening, said housing also having a continuous exterior side wall surrounding said blade at the height thereof and extending above said sail portions; (c) means for rotatably driving said blade at a predetermined tip speed below 14,000 FPM, yet sufficient to cause the cutting edges of said blade to cleanly cut blades of grass, clear cut grass particles from the edges, and to impart sufficient momentum to the cut grass particles to allow collection thereof; (d) said cutting edges having sufficient sweep back and said blade having a predetermined blade diameter which is sufficiently small so as to develop sufficient centrifugal force at the predetermined tip speed so as to achieve cleaning of severed grass filaments from said cutting edges; (e) front and rear wheels mounted on said housing to enable movement of said mower over a ground surface at a controlled height thereabove; and (f) a grass-catching bag attached to said housing at said discharge opening. - View Dependent Claims (16, 17)
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Specification