Rotary feed cup having a spacer and a pivoted seal

Abstract

A feed cup mechanism, of the type generally used in grain drills, includes interchangeable feed wheels of various seed metering circumferential surfaces, of various tooth sizes or surface irregularities, and of various thicknesses. Interchangeable spacers of various thicknesses and of various peripheral sizes complement respective ones of the feed wheels to provide a metering passage having a suitable radial thickness for a particular type of seed and having a suitable width for metering a suitable quantity of seed. A pivoted seal is provided which cooperates with the various sizes of the feed wheels and with complementary ones of the spacers to prevent seed from passing from a receiving opening to a discharge spout except through the metering passage. Optionally, the pivoted seal is oscillated to agitate the incoming seed and thereby to provide more uniform metering of the seed. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to material fielding mechanism, and more particularly to feed cup mechanisms of the type which are commonly used on grain drills. 2. Description of the Prior Art The prior art in feed cup mechanisms of the type generally used on grain drills includes U.S. Patents as follows: U.S. Pat. Nos. Jessup 32,627; Jessup Re 2,782; Jessup Re 5,917; Westcott 176,719; Regan Re 8,819; Keedy 337,268; Bozard 899,711; Kirschmann 3,489,321; and Patterson et al. 3,680,742. Of particular interest is Westcott, U.S. Pat. No. 176,719, in which various widths of a seed wheel can be exposed to the grain to change the feeding rate. A movable gate moves in and out of the feed cup to complement the width of the feed wheel that is exposed to the interior of the feed cup. This type of feed cup mechanism is still used in a variation in which the movable gate may be rotated 90 degrees to allow rapid emptying and cleaning of the feed cup. Westcott's device has the advantage of ease in modifying the rate of seed being sown; but it has the disadvantage of a constant tooth size on the feed wheel, wheras smaller teeth are needed for small seeds and larger teeth are needed for large seeds. Also there is no provision for changing the radial thickness of the metering passage, so small seeds are not accurately metered and large seeds tend to be broken as they traverse the metering passage. Kirschmann, U.S. Pat. No. 3,489,321, is also of particular interest in that Kirschmann moves the drive shaft to effect a change in the radial thickness of the metering passage to provide more accurate metering of fine seed and to reduce the breakage of large seed. SUMMARY OF THE INVENTION In accordance with the broader aspects of this invention, there is provided a feed cup mechanism which includes a feed cup having a receiving opening for receiving seed, having a discharge spout for gravity discharging of seed, and having drive shaft apertures through the side walls thereof that are intermediate of the receiving opening and the discharge spout. A drive shaft is rotatably inserted through the drive shaft aperture and carries a feed wheel thereupon that includes a seed metering surface. A pivoted seal is mounted in the feed cup intermediate of the receiving opening and the discharge spout, and includes a swinging end that is gravity pressed proximal to the seed metering circumferential surface of the feed wheel to prevent seed from passing from the receiving opening to the discharge spout except through a metering passage that is provided between the seed metering circumferential surface of the feed wheel and a curvilinear inner surface of the feed cup. Feed wheels of various seed metering circumferential surfaces, of various surface irregularities of the respective seed metering circumferential surfaces, and of various widths, are provided for handling different sizes of seeds and for selectively adjusting the feed rates. Interchangeable spacers, having various thicknesses and various outer peripheral sizes, are provided to complement respective ones of the feed wheels to make up a total width which is substantially equal to the inside width of the feed cup. The pivoted seal has a width which is substantially equal to the combined width of paired ones of the feed wheels and spacers; and the swinging end of the pivoted seal cooperates with both the seed metering circumferential surface of a feed wheel and with a portion of the outer periphery of the paired spacers to effectively provide a seal between the receiving opening and the discharge spout. In one embodiment, the swinging end of the pivoted seal rests against the outer periphery of the spacer and does not touch the seed metering circumferential surface of the feed wheel, but is proximal thereto for effective sealing. In another embodiment, the swinging end of the pivoted seal rides against the seed metering circumferential surface of the feed wheel and is actuated upwardly by surface irregularities of the seed metering circumferential surface, thereby agitating the seed that is above the pivoted seal to prevent seed from bridging across the receiving opening, and thereby improving the accuracy of seed metering. It is a first object of the present invention to provide a feed cup mechanism having interchangeable feed wheels of various diameters to provide metering passages of larger radial size for larger seeds and of smaller radial size for smaller seeds. It is a second object of the present invention to provide complementary width feed wheels and spacers to change the width of the metering passage and thereby to change the rate of seed metering therethrough. It is a third object of the present invention to provide a self-adjusting seal that cooperates with the seed metering periphery of various diameters of feed wheels to prevent seed from flowing from the receiving opening to the discharge spout except through the metering passage. It is a fourth object of the present invention to provide a pivoted seal that cooperates with both the seed metering periphery of the feed wheel and with the outer periphery of the spacer to prevent seed from flowing from the receiving opening to the discharge spout except through the metering passage. It is a fifth object of the present invention to provide means for agitating the seed that is proximal to the receiving opening of the feed cup to prevent seed from bridging thereacross. It is a sixth object of the present invention to cam actuate the pivoted seal by contact with surface irregularities of the circumferential metering surface of the feed wheel and thereby to agitate the incoming seed. These and other advantages and objects of the present invention will be readily apparent by referring to the following detailed description wherein:

Dependencies are inferred from the claim text.