Lawn cutting device in particular lawn edge cutter

Claim 1

A lawn mower machine, in particular a lawn edge cutter, comprising: a base frame secured to a bearing axle, an immovable fork-shaped lower knife mounted immovably to said base frame, an upper knife means for cooperating with said lower knife being pivotally connected to said base frame, a rotatable roller rotatably mounted on said bearing axle in said base frame behind said upper knife means and longitudinally arranged in said base frame and adapted to roll in the ground, a lateral cam disc integrally connected to said rotatable roller on each side thereof and coaxially spaced therefrom for joint rotating movement therewith and each having a control curve constituting an undulating cam shaped peripheral edge, and said undulating cam shaped peripheral edges of said cam discs are phase off-set with respect to each other, a control fork means resiliently and tiltingly pivotally supported at a first pivot axle on said base frame in front of said rotatable roller and having a pivot plate and two lateral arms each extending rearwardly from said pivot plate on lateral sides of said rotatable roller, a roll disposed on each lateral arm and rollingly engaging one of said control curves, and said rolls disposed in a horizontal plane and extending inclined from said lateral arms toward said first pivot axle, said first pivot axle being inclined upwardly slightly from the vertical in a direction away from said rolls, said pivot plate forms a control slot, a driver member disposed in said control slot and rigidly connected with said upper knife means, a spring wound about said driver member between said pivot plate and said upper knife means and supporting said pivot plate adjacent to said driver member, thereby providing for adjustment of a cutting pressure, and, a protective cap arrestably and swingably disposed about said roller and said bearing axle and including an integral insert sleeve adapted to receive a pusher means, whereby, a pushing of said machine effects a rolling of said rotatable roller and a turning of said control curves which cooperatively oscillatingly pivots said control fork about said first pivot axle via said rolls, and said control fork in turn oscillatingly pivoting said upper knife means effecting a cutting cooperation with said lower knife.