US 4,048,788 AGranted

Rotary power mower with improved clutch and brake mechanism

AssigneeBriggs & Stratton Corporation

InventorsIgor Kamlukin, Joseph R. Harkness

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Abstract

A rotary power mower in which the cutter blade is fixed to the bottom of a cup-shaped rotor, freely rotatably suspended from a carriage that is slidably mounted for fore and aft movement beneath the deck of the mower chassis. The carriage is spring-urged to a position in which the outer face of the side wall of the cup-shaped rotor is frictionally engaged with a brake shoe fixedly carried by the mower chassis, to hold the cutter blade against turning; and a deadman control mounted on the handle of the mower and operatively connected with the carriage enables the operator to move the carriage against the force of the spring to a position in which the inner face of the side wall of the cup-shaped rotor is tangent to and frictionally engaged with the periphery of a drive wheel fixed to the engine drive shaft.

Claims12

Dependent claims

In a rotary power lawn mower having a wheeled chassis with a deck, a prime mover mounted on the deck with a drive shaft thereof projecting downwardly into the space below the deck, and a rotary cutter blade below the deck, improved clutch mechanism for drivingly connecting the cutter blade with said drive shaft, comprising:

A. a drive wheel drivingly connected with and driven by said drive shaft, said drive wheel being located below the deck of the chassis and constrained to rotate about a substantially vertical axis that is fixed with respect to the chassis;
B. a ring fixed with respect to the cutter blade, said ring having internal and external circular surfaces, the diameter of each of which is larger than that of the drive wheel;
C. a carriage;
D. means movably mounting said carriage on the chassis and constraining the same to bodily movement in opposite directions along a defined path transverse to the axis of the drive wheel;
E. bearing means freely rotatably mounting the ring on said carriage with the ring encircling the drive wheel and its axis parallel to that of the drive wheel, so that upon bodily movement of the carriage in one direction the internal circular surface of the ring is tangentially and frictionally engaged with the periphery of the drive wheel to establish a torque transmitting connection between the prime mover and the cutter blade;
and
F. manually operable means for effecting bodily movement of the carriage in said direction.

4 more elements

In a rotary power lawn mower having a wheeled chassis with a deck, a prime mover mounted on the deck with a drive shaft thereof projecting downwardly into the space below the deck, and a rotary cutter blade below the deck, the mower having a handle projecting from its chassis, an improved combination clutch and brake mechanism including a deadman control on the handle, for drivingly connecting the rotary cutter blade with the prime mover as long as the operator holds the deadman control in its operative position and for automatically stopping rotation of the cutter blade without stopping the prime mover when the operator releases the deadman control, said improved clutch and brake mechanism being characterized by:

A. a drive wheel located below the deck of the chassis, drivingly connected with said drive shaft and constrained to rotation about a fixed vertical axis;
B. a rotor fixed with respect to the cutter blade, said rotor having a substantially cylindrical wall larger in diameter than that of the drive wheel;
C. means freely rotatably mounting said rotor below the deck of the chassis with its axis parallel to that of the drive shaft and its substantially cylindrical side wall encircling the drive wheel, and for bodily movement thereof radially with respect to the axis of the drive wheel;
D. a brake shoe fixed at the underside of the chassis deck in position to be engaged by the outer surface of the substantially cylindrical wall of the rotor when the latter is bodily moved in one direction;
E. spring means reacting between the chassis and the means mounting the rotor for bodily movement, yieldingly urging the latter in the direction to effect braking engagement of the rotor with the brake shoe;
and
F. motion transmitting means operatively connecting the deadman control with the means by which the rotor is freely rotatably mounted, through which maintenance of the deadman control in its operative position restrains the rotor from contact with the brake shoe and drivingly connects it with said drive wheel.

4 more elements

Dependencies are inferred from the claim text.