Patent · US Expired

Clutch-brake mechanism for rotary mower engines

US4205737A · kind A · utility

16Cited by
3References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 2, 1977
Grant dateJun 3, 1980
Priority date
Expiry dateSep 2, 1997

Classification

  • Technology area (CPC A)Human Necessities
  • CPC primaryA01D2101/00
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A completely enclosed combination clutch and brake mechanism permanently mounted at the bottom of a vertical shaft internal combustion engine of the type used to power rotary lawn mowers, is interposed between the crankshaft of the engine and a coaxial blade shaft projecting down from the bottom of the enclosed clutch and brake mechanism to have the cutting blade of the mower fixed thereto. A rotatable driving member fixed to the engine crankshaft and a rotatable driven member fixed to the blade shaft are drivingly coupled by radially outwardly movable clutch elements carried by the driven member and frictionally engaged with a radially inwardly facing circular surface on the driving member. Such frictional engagement results from the application to the clutch elements of both spring force and centrifugal force. The spring-force-produced frictional engagement effects transmission of rotation to the driven member from stand still to the speed at which the centrifugal-force-produced frictional engagement is capable of transmitting full engine torque to the blade shaft, but is incapable--due to slippage--of stopping the engine when the brake is applied, in which event rotation of the …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.