Power transmission device for power-operated lawn mowing machine

Claim 1

A power transmission device for power-operated lawn mowing machine, which comprises in combination: (a) a machine body; (b) a prime mover mounted on one part of said machine body; (c) a rotational shaft for said prime mover; (d) a concentric shaft rotatably fitted around said rotational shaft for the prime mover at the bottom part thereof; (e) a cutting blade fixedly secured to said concentric rotational shaft; (f) a pair of frictional clutch means, one of which is fixedly secured to said prime mover shaft, and the other of which is fixed onto the concentric rotational shaft around said prime mover shaft in a manner to be integrally rotatable with said concentric rotational shaft and movable in the axial direction of said shaft; (g) spring means to urge said rotational clutch means upward toward said fixed clutch means; (h) disc brake means fixedly secured to said movable engaging member of said pair of clutch means; (i) a cam plate fixed around said prime mover shaft in a rotatable manner; (j) a fixed braking disc secured to said cam plate; (k) a plurality of circumferential grooves formed in the surface part of said cam plate facing said disc brake means; (l) retainer means to hold therein a plurality of protruded members to be engaged with said cam grooves, said retainer means being provided between said cam plate and said rotational disc brake means, and being connected with an operating lever through a flexible wire for engaging and disengaging said clutch means; (m) a drive pulley provided on said prime mover shaft and a driven pulley provided on one part of a wheel axle; and (n) a pulley belt extended between said drive and driven pulleys.