Patent ID: 7971421

Claim:
A reel mower, which comprises: (a) a reel mower frame on which a power source is carried; (b) a traction drive for propelling the reel mower frame across the ground, the traction drive being powered by the power source; (c) at least one reel cutting unit carried on the reel mower frame, the reel cutting unit having a reel cutting unit frame which includes a pair of transversely spaced apart side plates, wherein the cutting unit carrier frame carries: (i) a helically bladed cutting reel extending between the side plates with the cutting reel having opposite ends that are rotatably journalled in the side plates such that the cutting reel is rotatable about a substantially horizontal, transverse axis; (ii) a bedknife extending between the side plates which cooperates with the cutting reel such the rotatable cutting reel sweeps standing grass against the bedknife to cut the grass; and (iii) front and rear ground engaging wheel or roller supports rotatably carried by the side plates for allowing the reel cutting unit to be self supporting and to move over the ground; and (d) a suspension system for pivotally connecting the reel cutting unit frame to the reel mower frame such that the reel cutting unit can pitch about a substantially horizontal, transverse pitch axis and can roll about a substantially horizontal, longitudinal roll axis, wherein the suspension system comprises: (i) a U-shaped, downwardly facing, cutting unit carrier frame that includes a transverse cross member having downwardly extending, vertical support arms at either end thereof, wherein each support arm extends downwardly adjacent to one of the side plates and has a lower end that includes a circular hub located concentrically around the rotational axis of the cutting reel, wherein the support arms are pivotably connected to the reel cutting unit frame by the hubs such that the reel cutting unit frame pitches forwardly and rearwardly relative to the hubs about the rotational axis of the cutting reel with the rotational axis of the cutting reel forming the transverse pitch axis of the suspension system; and (ii) at least one pair of inclined rigid links pivotably connecting the transverse cross member of the cutting unit carrier frame to a portion of the reel mower frame such that the reel cutting unit rolls from side to side about the roll axis by rolling of the cutting unit carrier frame from side to side relative to the reel mower frame though a pivoting motion of the rigid links.