US2275724A - Grain separating chaffer - Google Patents

Description

March 10, 1942. c. M. BREMNER GRAIN' SEPARATING CHAFFER 2 Sheets-Sheet 2 Filed July 3l. 1939 C M. BRE/mm2 Patented Mar. 10, 1942 Nr orFicE GRAIN SEPARATING CHAFFER Claude M. Bremner, Regina, Saskatchewan, Canada, assignor of'fty percent to Andrew McLatchie, Tuberose, Saskatchewan, Canada Application July 3l, 193,9, Serial No. 289,687

4 claims.

My invention relates to improvements in chaifer-screens for use in association'with grain threshing machines or combines, an object of this invention being to provide a device of the character herewithin described which in propor tion to its over-all dimensions provides a greater perforated area than is to be found in threshing machines of conventional design for deecting an air blast therethrough.

A further object of my invention is to provide. a chaiiing screen of the character herewithin described in which there are no horizontal surfaces upon which grain may slide uselessly while the associated machine is in operation and the screen oscillating. L

A further object of my invention is to provide a chaing screen of the character herewithin described in which there are no surfaces, pockets or recesses upon or in which kernels of grain may jump about idly without gravitating downwardlyV to the conveyor trough.

A further object of my invention is to provide a chaing screen of the character herewithin described by the use of which, due to the deflector design thereof, it is possible for a forced:

draught of air to penetrate a deeper bed of material above the screen than is possible by the use cf chaii'ing screens of conventional design thereby preventing loading or drifting and the consequent loss of grain caused thereby.

A further object of my invention is to provide a chaing screen of the character herewithin described by the use of which in association with a combine, greater eiliciency is obtained during a deviation of the machine from the horizontaly or during movement thereof over uneven ground.

A further object of my invention is to provide a chaing screen of the character herewithin described by the use of which in association with a combine and when engaged in straight com-f 1 bining less trouble is experienced with sap from green weeds travelling through the combine with the ripe grain.

A further object'of my invention is to provide a chatting screen in which frame-spanning, strengthening members of thick section are eliminated, such members reducing considerably the Cil effective area and accordingly, separating efand such other minor objects as may appear as the specification proceds, my invention consists essentially in the arrangement and construction of parts all as hereinafter more particularly described, reference being had to the accompanying drawings, in which:

Figure 1` is a perspective view of my improved chaing screen.

Figure 2 is a side View of the chafng screen illustrated in Figure 1.

Figure 3 is a side View of my chaing screen in situ within a threshing machine andv showing the adjacent'parts of a threshing machine to indicate the relative positionof my screen therein.

Figure 4 is a full sized'dimensioned section of one of my air draught deflectors.

' In the drawings like characters of reference indicate corresponding parts in the different figures.

My invention comprises a rectangular frame I designed to oscillate in the direction of the longer sides 2 in the conventional manner, the speed of such oscillation being approximately two hundred and twenty-five throws per minute, each of about three inches in length.

Spanning the sides 2 `and therefore normal to the direction of oscillation of the frame, is a plurality of parallel air stream deflectors 3, each of which comprises what I term as a steep draught over-plate 4, a shallow draughtunder-plate" 5 and a low pressure, connecting'shelf 6, the deectors being preferably manufactured of one f piece sheet metal. It will be noted that my overplate l is of greater'width than the under-plate 5, the approximate width of the former being two and one-eighth inches while that of the latter is approximately one 'and three-eighths so that the over-plate projects upwardly beyond the underplate and hoods the same.

It will be `noticed that the obtuse angulation above the horizontal,` of vmy shallow draught under-surface 5 (considered from the fan side of my vchaiiing screen) is greater than that of the over-plate 4, the angulation which the former makes with the horizontal being approximately 152, while that which the latter makes is approximately 134. v

The width of my low pressure shelf 6 is approXima-tely three-eighths of an inch while the width of the upper portion of my over-plate, or in other words, the width from the upper edge thereof down to the line where it meets the inner edge of the low pressure shelf, is seven-eighths I of an inch.

By reference again to the accompanying Figure 4, it will be noted that when my air stream deiiectors are manufactured from one piece sheet metal that the under-plate and shelf 6 are maintained in their correct relative positions to the over-plate 4 by angulating the sheet metal again to form the lining strip 1, around the edge of which the sheet metal is formed to provide a beaded edge 8.

It will be noted that the over-plate 4 and the under-plate 5 converge to form a wind screen cutting edge 9 and at this point I would state that the edges 9 of each of my wind screen deectors are spaced three inches apart, from which it will be seen that since the throw of the screen during operation is vthree inches also, the deectors will move back and forth and noporf tion of the area withinthe frame can escape being traversed by my deilectors.

I would finally mention in connection with my wind stream deectors that extending through the triangulated hollow center of each, is a tierod I9, to assist in holding theisides 2 together and although various methods maybe resorted to to maintain my wind stream deflectors at the correct degree of angulation with respect to the horizontal, the most satisfactory-and economical is probably to provide a rivet head II .at one end of each tie-rod while screw-threading the opposite end and then wrenching a nut I2 tight over the screw-threaded portion and against the sides so that each deflecter is cramped into position.

Spanning the'end members I2 are a number of straw and chaff intercepters I3.in the form of parallel round wiresA spaced half an inch apart and thus running in the direction of oscillation of the cha'ing screen. VIt is immaterial whether each of these wires is a separate wire and secured at each end as by means of .a staple for instance, in the end members, or whether a continuous wire is employed and threaded back and-,forth between the end members but it should be noted that the wires extend through a plurality of aligned holes punched through the steep-draught over-plate 4 of my wind screen deiiectors slightly above the point where the inner edge of the low pressure shelf 6 meets it.

By reference to the accompanying Figure 3 wherein I have shown thel adjacent parts of a threshing machine in order to assist inexplaining the position occupied by a chafling screen therewithin, that a wind screen from the fan housing I4 of the threshing machine passes through or around the conventional lower screen I5 and is then split or divided by the edges 9 into a plurality of steep draughts of air indicated by the arrows I8 and also into a plurality of shallow draughts of air indicated by the arrows I1.

Thus it will be seen that between the .steep and shallow draughts there are areas of low pressure above each of the pressure shelves 6, through which grain maydrop into the conveyor trough I9 prior to being elevated by the convey- I ors 20.

arrows 2l and 22, represent the path of straw and chaff from the straw-Walkers 23 and the tray 24. In this iigure also it will be understood that the portion designated by the numeral 25 represents the sheaf intake conveyor while the numeral 26 designates a conventional threshing cylinder through which material is deposited onto the corrugated tray 21. Finally I would mention thatthe path generally designated by the numeral 28 represents the conventional tailing trough and tailing elevator, such parts being illustrated solely for the purpose of locating my novel chaing screen within a threshing machine.

`Since various modilications can be made in the above invention, and many apparently widely diierent embodiments of same, made within the scope of the claims without departing from the spirit and scope thereof, it is intended that all matter contained in the accompanying speciiication shall be interpreted as illustrative only and notin a limiting sense and I .desire onls7 such limitations placed thereon asl are specifically expressed in the4 accompanying claims.

What I claim as my invention is:

l. A chafng screen for use in combination with a grain threshing machine or combine comprising an oscillating rectangular frame and a plurality of wind stream deflectors .spanning said frame, each of said wind stream deflectors having a shallow draught under-plate and a steep draught over-plate, said over-plate projecting upwardly beyond said under-plate and hooding they same, said under-plate and said over-plate being positioned at an obtuse angle to the horizontal with respect to the source of said Wind stream, the obtuseangulation of said shallow draught. under-.plate ibeng greater than the obtuse angulation of saidsteep K.draught over -plate,

said plates'convergingdownwardly to form an air stream cutting edge, and a connecting shelf extending between the upper edge of said underplate and a line extendingmedially of the width of said over-plate.

2. The chafiing screen as defined in claim l which includes a plurality of straw and chai intercepters in the form of parallel wire stringers spanning said frame.

3. 'I'he chafing screen as defined in-claim 1 in which said wind stream delectors span said frame at right anglesto the direction of oscillation thereof and which includes a plurality of straw and chaff intercepters taking the form of parallel wire stringers spanning said frame in its direction of oscillation.

4. A charting screenfor use in combination with a grain threshing machine or combine comprising an oscillating rectangular frame and a plurality of wind stream deflectors spanning said frame, each of saidwind stream deflectors having a shallow draught under-plate and a flat steep draught over-plate projecting upwardly beyond said under-plate, each of said under-plates and each of said over-plates being positioned at an obtuse angle to the horizontal with respect to the source of said wind stream, said over-plate hooding said under-plate, the obtuse angulation of said under-plate being greater than the obtuse angulation of said over-plate, said plates converging downwardly to form an air stream cutting edge.

CLAUDE M. BREMNER.

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