Rotary mower spindle brake

Claim 2

In a rotary lawnmower including an engine, a housing for said engine, a drive shaft having a portion depending from said engine and said housing, said drive shaft depending portion including screw means thereon, a cutting blade, a hub attached to said blade and being provided with an internal passage screw threaded complimentary to said screw means, means for retaining said hub on said shaft with said internal passage threadably engaged with said screw means; and said hub having its upper surface provided with a friction material forming a brake with said housing when said engine is shut off and said hub moves upwardly along said screw means and into contact with said housing.

Claim 3

In a rotary mower as recited in claim 1 and wherein spring means are interposed between said hub and said retaining means for biasing said hub to move to braking position when said engine is shut off.

Claim 4

In a rotary mower belt driven from a tractor engine, a housing for said mower, a plurality of spindles rotatably mounted in said housing, cutting blades attached to the lower ends of said spindles for rotation therewith, sheaves attached to upper portions of said spindles, a V-belt operatively positioned about said sheaves for driving same, one of said spindles having a second sheave mounted on the upper end thereof for driving said spindle and said sheaves, said second sheave being drivenly connected to said tractor engine, said second sheave having a screw connection to said one of said spindles, a stationary member carried by said housing adjacent to said second sheave, said second sheave having a lower surface frictionally engaging said stationary member as a result of said tractor engine being declutched from said second sheave and said second sheave being screwed down into breaking relation with said stationary member as a result of the inertia of rotation of said blades.

Claim 5

In a rotary mower belt driven from a tractor engine, a housing for said mower, a plurality of spindles rotatably mounted in said housing, cutting blades attached to the lower ends of said spindles for rotation therewith, sheaves attached to upper portions of said spindles, a V-belt operatively positioned about said sheaves for driving same, one of said spindles having a second sheave mounted on the upper end thereof for driving said spindle and said sheaves, said second sheave being drivenly connected to said tractor engine, said second sheave having a screw connection to said one of said spindles, a stationary member carried by said housing adjacent to said second sheave, said second sheave having a lower surface frictionally engaging said stationary member as a result of said tractor engine being declutched from said second sheave and said second sheave being screwed down into breaking relation with said stationary member as a result of the inertia of rotation of said blades.

Claim 6

In a rotary mower as recited in claim 3 and wherein said screw connection comprising a collar member attached to the upper portion of said one spindle and having a screw configured periphery, said second sheave having a threaded passage therethrough with said screw configured periphery engaged with said threaded passage so that a difference in revolution per minute of said sheave relative to said spindle results in a movement of said sheave towards or away from said stationary member.

Claim 7

In a rotary mower as recited in claim 3 and wherein spring means are interposed between said second sheave and said drive sheave for preventing said drive sheave from becoming jammed against said stationary surface.

Claim 8

In a rotary lawnmower including an engine, a housing for said engine, a drive shaft depending from said engine and said housing, a cutting blade, a hub attached to said blade and being threadably engaged with said drive shaft, means for retaining said hub on said shaft, and said hub having its upper surface provided with a friction material forming a brake with said housing when said engine is shut off and said hub moves upwardly on said drive shaft and into contact with said housing.

Claim 9

In a rotary lawnmower including an engine, a housing for said engine, a drive shaft depending from said engine and said housing, a cutting blade, a hub attached to said blade and being threadably engaged with said drive shaft, means for retaining said hub on said shaft, and said hub having its upper surface provided with a friction material forming a brake with said housing when said engine is shut off and said hub moves upwardly on said drive shaft and into contact with said housing.