Gravity feed grading unit

A grading unit divides a supply of objects into constituent portions and directs the divided portions to various predefined locations. At least one passageway is defined, being sufficiently inclined so that the supply of objects flows through the unit solely under the force of gravity. Diverting gates disposed along the passageway selectively divert objects from the passageway toward and through an associated secondary opening located adjacent the passageway. A dividing chute associated with each secondary opening is provided to direct the diverted objects to one of a plurality of different predefined locations.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a device for grading a supply of objects 
which flow through the device under the force of gravity. 
2. Description of the Related Art 
Conventional grading units employ conveyor belts to transfer a supply of 
objects to be graded through the unit. Push-off or pull-off gates are 
provided on one or both sides of the conveyor belt to selectively divert 
objects from the supply of objects off of the conveyor belt to be 
transmitted to another location. 
Such conventional systems are of limited speed and efficiency. Conveyor 
belts typically move at relatively low speeds. In addition, where pull-off 
gates are employed, only two conveyor belts carrying a supply of objects 
to be sorted can be used, and where push-off gates are employed, only one 
conveyor belt can be used. Also, with pull-off or push-off gates, there is 
a minimum required distance between objects moving on the conveyor. 
Moreover, the necessary motors, rollers, and belts of a conveyor belt 
system contribute considerable cost and complexity to the system and 
further require excessive space to accommodate the conveyor system. 
SUMMARY OF THE INVENTION 
It is an object of the present to overcome the above-described shortcomings 
present in conventional grading units. In accordance with this objective, 
the grading unit of the present invention is faster than conventional 
conveyor belt systems because the supply of objects moves through the unit 
more quickly and because the construction of the unit is such that it can 
be configured to accommodate several parallel streams of objects flowing 
through the unit. The present invention does not employ a conveyor belt 
and therefore eliminates the necessary motors, rollers, and belts that 
accompany a conveyor belt system. Accordingly, the cost, complexity, and 
spatial requirements of the present invention are reduced as compared to 
conventional conveyor belt based grading units. 
In accordance with the principles of the present invention this objective 
is achieved by a grading system for dividing a group of objects into 
constituent portions having structure defining at least one passageway 
having an exit and oriented to receive a supply of objects and through 
which the supply of objects flows toward the exit. The passageway is 
inclined so that the supply of objects flowing therewithin flows 
substantially solely due to gravitational forces. The system further 
includes means for selectively diverting objects flowing within the 
passageway into any of a plurality of different predefined branch 
passageways or locations. 
By employing gravity to move the objects down the passageway in which the 
objects can be selectively diverted, instead of a conveyor belt, the 
system is faster, less complex, more cost effective, and less space 
consuming. By employing vertically arranged diverting means, it is not 
necessary to maintain a minimum spacing between objects flowing through 
the passageway, thus further simplifying and expediting the sorting 
process. 
Other objects, features, and characteristics of the present invention, as 
well as the methods of operation and functions of the related elements, 
and of the combinations of parts and economies of manufacture, will become 
apparent upon consideration of the appended claims with reference to the 
accompanying figures, all of which form a part of this specification.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EXEMPLARY EMBODIMENT 
A grading system 10 according to the present invention, as depicted in FIG. 
1, includes a structural support frame 12 preferably including inner 
vertical members 14, outer vertical members 16, and various horizontal 
members 18. 
An infeed apparatus 20, typically a conveyor belt from a processing unit 
(not shown), carrying a stream of objects 22 to be divided, or sorted, by 
the grading system 10 is disposed generally directly above the grading 
system 10. The end of conveyor 20 is disposed substantially directly over 
grading system 10 so that a stream of objects 22 falling off the end of 
conveyor 20 will be received in the grading system 10 and divided into 
constituent parts in a manner to be described below. 
A plurality of take-away conveyor belts 24 can be provided below the 
grading system 10 to receive from the grading system 10 divided 
constituent portions of the supply of objects in a manner to be described 
more fully below and to carry the divided constituent portions to other 
predefined locations for further processing or the like. 
As shown in FIG. 1, a number of flap mechanisms 26, or gates, are arranged 
in a vertically spaced relation along the inner vertical members 14. 
Although the depicted embodiment shows the flap mechanisms 26 arranged in 
3 opposing pairs, the present invention contemplates other configurations 
of the flap mechanisms, such as more or fewer flap mechanisms, or having 
the flap mechanisms arranged orthogonally to one another. A preferred 
embodiment of the present invention includes 3-9 opposing pairs of flap 
mechanisms. 
The flap mechanism 26 includes a flap door 28 and an actuator 30. The flap 
doors 28 are pivotably coupled at a lower end thereof to the top of an 
outwardly sloping dividing chute 32 associated with each flap mechanism 
26. Each actuator is pivotably coupled at one end thereof to the flap door 
28 and at the opposite end thereof to a portion of the structural support 
frame 12. 
The inner vertical members 14 and the flap doors 28 disposed vertically 
along the inner vertical members 14 define a passageway 34 having an 
infeed opening 35 and an outfeed opening 36 and which is positioned to 
receive a supply of objects 22 falling off the end of conveyor 20 and into 
the infeed opening 35. The outfeed opening 36 of passageway 34 empties 
into one of a group of predefined locations, in the illustrated 
embodiment, one of the seven take-away conveyors 24. 
Passageway 34 is inclined so that the supply of objects 22 received from 
the end of conveyor 20 proceeds through passageway 34 propelled solely by 
the force of gravity. In the preferred embodiment of the present 
invention, passageway 34 is vertical. 
As shown in FIG. 1, each flap mechanism 26 can be opened (i.e., moved to an 
operative position) by extending the associated actuator 30 to pivot flap 
door 28 outwardly and into the passageway (as shown by the top right-hand 
flap mechanism 26 in FIG. 1) to selectively divert a portion of the supply 
of objects flowing through the passageway 34 from its normal undiverted 
path toward exit 36. Flap door 28 can also be moved back into its 
inoperative, or closed, position in which it does not divert objects 
flowing through the passageway. As can be appreciated from FIG. 1, when a 
flap mechanism 26 is opened, the objects flowing through passageway 34 
which contact the flap door 28 are diverted through a secondary opening 37 
associated with the flap mechanism into the outwardly sloping chute 32 to 
which the flap door 28 is pivotably connected. The sloping chute has a 
receiving end 31 and a drop-off end 33. Upon being diverted to the chute 
32, the diverted objects will slide along the chute 32 from the receiving 
end 31 to the drop-off end 33 and will be directed to a one of the seven 
take-away conveyors 24 or another predefined location. It will be 
appreciated that by selectively opening flap mechanisms 26 one at a time 
as a supply of objects flows down passageway 34, the supply of objects is 
divided among the take-away conveyors 24, or other predefined locations, 
into constituent portions. 
The flap mechanisms shown and described represent the preferred method of 
selectively diverting objects from passageway 34. The present invention 
contemplates, however, other means for accomplishing the diversion as 
well, such as shown in FIG. 3 for example, blasts of air from nozzles 50 
directed across passageway 34 to blow objects which encounter the blast to 
one side or the other into an associated secondary opening. 
With the flap mechanisms 26, or other diverting means, arranged along 
mutually opposed sides of the passageway 34, as shown, or along a single 
side of the passageway, it is possible to arrange any number of similar 
passageways in parallel, side-by-side fashion. In FIG. 1, flap mechanisms 
38 of a passageway adjacent to passageway 34 are shown in both an 
operative and inoperative position. In a preferred embodiment, side by 
side parallel passageways are provided with coincidentally positioned flap 
mechanisms, as shown in FIG. 1. 
Parallel arrangement of multiple passageways is not feasible with 
conventional, substantially horizontal conveyor belt grading systems which 
employ pull-off or push-off gates because the gates would merely divert 
the objects from one passageway to an adjacent passageway. 
This invention has been described with reference to what is currently 
considered to be the most practical and preferred embodiment. This is not 
meant, however, to limit the present invention. Rather, various 
modifications and arrangements are intended to be included within the 
spirit and scope of the appended claims.