Clip control system for walk reel mower

A method of controlling and selecting clip in a reel cutting unit having a reel with a plurality of circumferentially spaced blades that are cooperable with a bedknife to cut grass therebetween, the clip comprising a forward distance of travel of the reel cutting unit over the ground in a time interval determined by the length of time that it takes for successive blades on the reel to contact a predetermined reference spot on the bedknife, which comprises:

• (a) providing a drive system for rotating the reel, wherein the drive system comprises:
• (i) a flexible endless transmission member;
• and
• (ii) first, second and third circular members arranged in drive, driven and idler positions in engagement with the flexible transmission member, the circular member in the drive position being operatively connected to an input drive shaft and the circular member in the driven position being operatively connected to the reel for rotating the reel, wherein the first, second and third circular members have different diameters from one another and may be interchangeably used in any of the drive, driven and idler positions to provide six different possible clips when arranged in six different arrangements as follows:
• (1) a first arrangement in which the first circular member is in the drive position, the second circular member is in the driven position, and the third circular member is in the idler position;
• (2) a second arrangement in which the first circular member is in the drive position, the third circular member is in the driven position, and the second circular member is in the idler position;
• (3) a third arrangement in which the second circular member is in the drive position, the first circular member is in the driven position, and the third circular member is in the idler position;
• (4) a fourth arrangement in which the second circular member is in the drive position, the third circular member is in the driven position, and the first circular member is in the idler position;
• (5) a fifth arrangement in which the third circular member is in the drive position, the first circular member is in the driven position, and the second circular member is in the idler position;
• and
• (6) a sixth arrangement in which the third circular member is in the drive position, the second circular member is in the driven position, and the first circular member is in the idler position;
• (b) selecting and arranging the first, second and third circular members in one of the six different arrangements to select the clip that is provided by the one selected arrangement;
• and
• (c) conducting a grass mowing operation while propelling the reel cutting unit over the ground at a substantially constant ground speed and while rotating the input drive shaft at a substantially constant rotational speed.