In recent years, combines have become very large in size, especially for purposes of rendering the same capable of harvesting very wide swaths of crop material, thresh the same, and contain the threshed material in suitable storage compartments included in the combine. Enlargement of the size of the combines also has resulted in the operator being positioned in a cab or platform elevated a substantial distance upon the harvesting portion of the combine supported at the forward end thereof. In a number of combines of this type, the cab or seating platform is mounted above a feeder box in which an elevator is operable to move the material cut by the header at the forward end of the combine to the threshing mechanism rearwardly of the feeder box. In many situations, the operator actually is located several feet above the level of the ground and a number of feet above the mechanism below the cab or platform.
It also is often desirable for the operator to know the relative speed at which the combine is operating, especially for purposes adjusting the speed in accordance with the thickness or density of the crop being harvested and thereby not place a burden upon the operating mechanism of the combine, especially the engine thereof, which generally is a diesel engine. Heretofore, however, there has not been any simple but effective means for visually indicating to the operator of the combine the general speed at which it is functioning. It is old, of course, to employ tachometers associated with engines, especially automobile engines, to indicate the speed of the engine. Therefore, engine speed-indicating means is not practical for a combine, particularly where the principal engine of the combine operates a vari-drive on the forward part of the combine which distributes power, particularly to the cutting means of the header, the elevator of the feeder house and other related operating mechanism associated therewith.
According to the prior art, it is old, for example, to provide visible indicating means, of a relatively simple nature, to permit an operator to observe the amount of the float of a header connected to a combine, but in no way indicating the speed of operation of the combine attachment. Such a device is illustrated in prior U.S. Pat. No. 3,349,747, dated Oct. 31, 1967, to Vande Wiele. Similarly, prior U.S. Pat. No. 3,967,437, to Mott et al, dated July 6, 1976, shows a relatively simple indicating means visible to the operator of the combine and functioning to indicate the position of the uppermost area of the cutter bar in the header of a combine. Again, however, no indicating means are disclosed for purposes of revealing to a combine operator, the speed of the operation of the combine attachment.
It is the principal purpose of the present invention to provide a very simple speed-indicating means to visually indicate readily to the operator of the attachment, the speed of operation of the functioning mechanisms of the combine attachment, details of which are set forth below.