(1) Field of Invention
This invention relates to a metering device for dispensing granular material in a predetermined regular manner. In particular it relates to a metering device particularly useful in conjunction with a chisel-coulter for seeding and/or dispensing granular fertilizer.
(2) Description of the Prior Art
It is known, for example, in New Zealand specification No. 126,307, to employ a rotatable disc having resilient facing material thereon to frictionally engage granular material at an orifice in a substantially flat surface and to urge the granular material across the flat surface to a discharge area. In so doing the individual granules compress the resilient material enhancing its carrying capacity. While such a device is satisfactory for somewhat uneven delivery for granular material it suffers from the disadvantage that the discharge orifice can be rather easily blocked thus cutting off delivery or, on the other hand, the granular material might be discharged in a rush and spread out unevenly over the face against the resilient material is rotating. In either case, metering is unequally controlled. With rapidly escalating costs of seeds and fertilizer, inefficient metering of these materials can be highly detrimental to economic farming.
It is also known from U.S. Pat. No. 3,172,574 that a roller having a resilient surface can be positioned to close the open bottom of a V-shaped trough and delivery of seeds, for example grass seeds, or fertilizer in a curtain at the bottom of the trough can be effected by rotation of the roller. The surface against which the roller rotates and over which material is transported is a substantially non-resilient flat surface. While delivery of the granular material can be effected, consistently metered delivery cannot be achieved for similar reasons as suggested as hereinabove with respect to the other embodiment described.
It is an object of this invention to provide a device for metering granular material in a regular manner.
It is a further object to overcome the disadvantages discussed hereinabove by at least to provide the public with a useful choice.