Harvesters – Gang – Rotating cutting reel
Patent
1988-01-19
1989-11-07
Hirsch, Paul J.
Harvesters
Gang
Rotating cutting reel
56DIG15, A01D 3444, A01D 3458
Patent
active
048783382
DESCRIPTION:
BRIEF SUMMARY
This invention relates to grass cutting machines with particular emphasis on machines for cutting golf greens.
When cutting golf greens, it is desirable for the cutting unit to be raised and lowered with precision at the margins of the green. With a single cutting unit, this can be simply achieved by the manual operation of a lifting handle. Where the machine carries more than one unit (and there are usually three cutting units) it is necessary for a mechanical lifting mechanism to be provided. As will be well understood, three cutting units cannot be positioned in a single transverse line since the total width of each unit exceeds the cutting width. A transverse in-line arrangement would therefore leave strips of grass uncut. To overcome this problem, three cutting units are typically arranged as a pair of wing cutters and a single central cutter positioned either in front of or behind the wing cutters.
If the spacing of the wing and central cutting units in the direction of motion is kept to a minimum, all three cutting units can be lowered or lifted simultaneously without significant degradation of the boundary between cut and uncut grass at the green edge. There are, however, problems in having all three cutting units so close together and for this reason prior art designs have often incorporated a significant spacing between the units in the direction of motion. Simultaneous lowering or lifting of all units would then tend to degrade the cut green boundary since the points on the ground at which the front and rear cutting units started or stopped cutting would be a significant distance apart. It has been proposed to introduce a time delay between the lowering of the front and rear units and between the lifting of the front and rear cutting units. This has not however, satisfactorily resolved the problem.
It is an object of this invention to provide an improved grass cutting machine in which cutting operations of cutting units spaced in the direction of motion of a moving machine are started at substantially the same reference point on the ground and, similarly, halted at substantially the same reference point. It will be understood that cutting operations of a unit can be started by lowering the unit to the ground or by engaging drive to an already lowered unit. Similarly, cutting operations can be halted by lifting a unit or by disengaging drive to the unit.
The present invention consists, in one aspect, in a grass cutting machine having spaced forward and rearward cutting units; respective unit control means for starting and stopping cutting operations of the units and common control means adapted to actuate said unit control means in response to a common cutting start signal or a common cutting stop signal, wherein there are provided distance transducer means adapted to supply the common control means with a distance signal indicative of the distance travelled by the machine, the common control means being adapted to space actuation of the respective unit control means by a time interval computed in response to said distance signal and the known separation of the cutting units in the direction of motion such that, when the machine is moving, the cutting units start cutting operations at substantially the same point on the ground and stop cutting operations at substantially the same point on the ground. Preferably, there are further provided speed threshold means adapted to supply the common control means with a speed signal indicative of whether the ground speed of the machine is above or below a pre-set threshold; the common control means being switched between a service mode corresponding to zero or very low ground speeds and a cutting mode corresponding to significant ground speeds in dependence on said speed signal and adapted in said service mode, to actuate said unit control means simultaneously in response to a common cutting start signal or a common cutting stop signal and, in said cutting mode, to space actuation of the respective unit control means by said time interval.
It will be unders
REFERENCES:
patent: 3177638 (1965-04-01), Johnson
patent: 3511035 (1967-10-01), Strasel
patent: 3563011 (1971-02-01), Bramley
patent: 3918290 (1975-11-01), Haffner et al.
patent: 4130980 (1978-12-01), Fardal et al.
patent: 4142348 (1979-03-01), Jordan et al.
patent: 4296409 (1981-10-01), Whitaker et al.
patent: 4458471 (1984-07-01), Herwig
patent: 4487002 (1984-12-01), Kruse et al.
patent: 4548027 (1988-10-01), Maeoka
Aldred Edward J.
Lloyd David J.
Hirsch Paul J.
Ransomes Sims & Jefferies PLC
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