Patent ID: 6883999

Claim:
A gearbox for a rotary concrete finishing trowel, comprising: (A) a housing; (B) a rotary input element that is supported by said housing and that is configured to be operatively connected to an output element of a prime mover of the trowel; (C) a rotary output element that is supported by said housing and that is configured to be operatively connected to a rotor of the trowel; (D) a torque transfer system that is supported by said housing and that is configured to transfer torque from said input element to said output element, said torque transfer system being constructed such that delivery of torque thereto by said input element imposes an axial thrust on at least one component thereof that drives said component to move axially from a first position thereof to a second position thereof; and (E) a brake that cooperates with said torque transfer system so as to automatically 1) release when said component is in said second position thereof, thereby permitting torque transfer from said input element, through said torque transfer system, and to said output element, and 2) engage when said component is in said first position thereof, thereby resisting torque transfer from said output element, through said torque transfer system, and to said input element.