GB1559378A - Mechanism for metering particulate material - Google Patents

Description

(54) MECHANISM FOR METERING PARTICULATE MATERIAL (71) We, MASSEY-FERGUSON PERKINS LIMITED, a British Company, of 33 Davies Street, London, WIY 2EA do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the followng statement: This invention relates to a mechanism for metering particulate material, and in particular to an adjustment or control mechanism therefor.

In the case of seed drills, it is quite a common practice to provide a common control shaft extending the length of the drill, to simultanteously control a movable gate member or flap on each of a series of seed metering mechanisms. However, problems arise where such a common control shaft is provided, in that whenever a service problem arises in relation to the gate member, it is necessary to dismantle all the seed metering mechanisms, at least partiallv.

We have appreciated that these problems can be alleviated by eliminating the common control shaft and providing individual controls for each of the gate members.

However the consequential problem then arises that some simple inexpensive means is needed whereby a farmer can easily set all the individual controls, of which there may be as manv as 30 or more. at the same setting. It is an aim of the present invention to provide means for meeting, at least in part, this need.

According to a first aspect of the invention there is provided a mechanism for metering particulate material as defined in claim 1 of the claims of this specification, and according to a second aspect of the invention, there is provided a planter or drill as defined in claim 14 of the claims. Further preferred features of the invention are set forth in claims 2 to 13.

The provision of first and second pairs of formations as defined in claim 1 enables three adjusted positions of the gate member to be obtained with only two formations on each side. In general, with 2 formations on one side and n formations on the other side, a total of 2n-1 adjusted position can be achieved in this way. The need for less than one formation on each side for each adjusted position means that the formations can be made larger whereby visual setting is made easier, and the possibility of making the formations by punching or pressing out of sheet metal arises.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which : Figllre I shows a perspective view of a combined seed and fertilizer drill ; Figure 2 shows a section through the seed and fertilizer metering mechanisms of the drill of Figure 1) in the plane indicated by arrows 11-11 therein ; Figure 3 shows a section through one of the metering mechanisms on the line indicated by arrows 1II-II1 in Figure 2; Figltre v shows an end view of the metering mechanism of Figure 3, the direction of viewing being indicated by arrow IV in Figure 2; Fignre 5 shows a perspective view of a housing, a gate member and a manually operable movable control member for the gate member, these items forming part of the metering mechanisms shown in Figures to to-1 ; Figltre ó shows a side view of the manually operahle movable control member of Figure 5 ; Figure 7 shows an end view of said control member as indicated by arrow VII in Figure 6; Figure 8 shows a plan view of said control member as indicated by arrow VIII in Figure 6; and Figure 9,10 and 11 illustrate diagrammatically the general principle of the invention.

As shown in Figure 1, a combined seed and fertilizer drill 10 comprises a frame 12 mounted on wheels 14 and carrying a combined seed and fertilizer hopper 16. A drawbar 18 is provided whereby the drill is trailed by a tractor. A series of seed and fertilizer metering mechanisms 20 and 22 respecitively, to be more fully described below, are provided to meter seeds and fertilizer through respective flexible rubber tubes 24 to a series of disc coulters 26. The coulters are actuated by a single-acting hydraulic ram 28 and four return springs 30.

Metering mechanisms 20 and 22 are identical in construction, constitute mechanisms for metering particulate material, and will be described in greater detail below.

As shown in Figure 2, the seed and fertilizer metering mechanisms 20 and 22 are secured by bolts 32 to the underside of hopper 16 on the forward and rearward sides thereof, respectively. A vertical internal flange 34 and a divider wall 36 mounted thereon divide hopper 16 into a forward seed compartment 38 and a rear fertilizer compartment 40. Apertures (not shown) are formed in the walls of these compartments to allow the passage of seed and fertilizer to the metering mechanisms and a throat plate 42 is provided for each metering mechanism to guide the flow of particulate material through the aperture in the desired direction.

A slidable blanking plate 44 is provided for each fertilizer metering mechanism to allow its aperture into fertilizer compartment 40 to be blanked off if desired.

Referring now to Figures 2 to 8, each of the seed and fertilizer metering mechanisms 20 and 22 comprises a somewhat box-like housing 46 (best seen in Figure 5) formed with apertured flanges 48 whereby it is secured by bolts 32 to the hopper 16.

Housing 46 has side walls 50, 52 linked by integral end walls 54, 56 and is formed by bending a single piece of sheet metal.

A movable gate member 58 comprising a curved tongue or flap is pivotally mounted in housing 46 between walls 50, 52. The gate member is connected to a manually operable movable control member or lever 60.

A rotatable metering member in the form of a fluted roller 62 is mounted on a square section drive shaft 64 to co-operate with gate member 58. Roller 62 has formed integrally therewith a sleeve (not shown) through which drive shaft 64 extends. At one end of the sleeve a colar 66 having a grub screw 68 (which extends through a hole in the sleeve) locks fluted roller 62 to shaft 64. Between ftuted rotter 62 and cottar 66 is a cylindrical blanking roller 70 mounted on the sleeve of fluted roller 62 so as to be freely rotatable with respect thereto. The blanking roller fits closely into an outwardly flanged aperture 72 in side wall 50 of housing 46. A stop bar 74 on the blanking roller is provided to engage housing 46 to prevent rotation of the blanking roller with the fluted roller and the shaft 64.

Fluted roller 62 projects through an aperture 76 in wall 52 of housing 46, with clearance. The gap between the edge of aperture 76 and the fluted roller is closed by a pair of washers, that is to say by an internally fluted sealing washer 78 into which the fluted roller fits closely (but so as to be free to slide therethrough lengthwise of shaft 64) and a flanged bearing washer 80.

The fluted washer necessarily rotates with the fluted roller 62. The bearing washer 80 is proportioned to fit closely into aperture 76 and has flanges 81 which abut the outer surface of side wall 2 of housing 46 and which also prevent rotation of the bearing washer. The fluted washer 78 nests inside an annular flange 82 (see Figure 3) on bearing washer 80.

A U-shaped retaining spring 84 bears against flange 82 to retain the washer assembly 78. 80 in position. The depth of flange 82 is such that there is a nominal clearance between spring 84 and the rotatable fluted washer 78. The closed end of spring 84 is located in a hook 86 (see Figure 2) pressed out of side wall 52 of housing 46.

The free ends of spring 84 resiliently hold themselves in noches 88, 90 formed in end walls 54,56.

Gate member 58 is connected to control lever 60 so as to be pivotable thereby. A coiled compression spring is provided to allow movement of the gate member relative to the control lever under overload conditions (e. g. if a hard lump of fertilizer should pass through the metering mechanism). The connection between the gate member and the control lever will now be described with reference to Figures 2 to 5.

As shown in Figure 2, gate member 58 comprises a curved tongue or flap 92 formed integrally with a generally D-shaped (as seen in Figure 2) flap support portion 94 carrying a first spring location stud 95. Flap support portion 94 is (as shown in Figure 3) channel shaped in cross-section and fits between side walls 50, 52 so as to be freely movable between them. The flap support portion is apertured and pivotally mounted on a pair of interfitting sleeve members 96, 98 which are themselves pivotally mounted in apertures formed in the housing side walls 509 52. Sleeve members 96, 98 are secured by a bolt 100 and a nut 102 to control lever 60 and are located laterally with respect to side walls 5O, 52 by a shoulder 104 on sleeve member 98 and by control lever 60 itself.

Control lever 60 fits into a slot (see Figure 5) formed in the end of sleeve member 98 and is thereby located in fixed angular relationship to the sleeve member. A second spring location stud 106 is connected to and formed integrally with sleeve member 98 by a neck 108. A shoulder 110 on nech 108 abuts the inner end 112 of flap 92.

A coiled compression spring 114 fits between studs 95 and 106. Thus it can now be seen firstly that flap 92 is free to pivot downwards (clockwise as seen in Figure 2) relative to control lever 60 (while compressing spring 114). Secondly, upward movement of lever 60 moves flap 92 upwards (by moving stud 106 downwards and transmitting thrust through spring 114 to stud 95).

Thirdly, downward movement of lever 60 moves flap 92 downwards by direct abutment of shoulder 110 with the end 112 of the flap.

Adjustment means 118 for providing stepwise adjustment of control lever 60 and hence of gate member 58 relative to housing 46 comprises a first pair of spaced formations 120,122 carried by the control lever and four spaced formations 124,126,128, 130 (any consecutive two of which constitute a pair of spaced formations for the purpose of the definition of this invention) carried by side wall 50 of housing 46. Side wall 50 constitutes (for the purpose of the definition of the invention) structure carrying the second pair of formations.

The four spaced formations 124,126,128 and 130 are formed by being punched or stamped out of the sheet metal of housing side wall 50. The shape of each of these formations is approximately a semi-circle and the four formations are positioned on an imaginary arc of a circle centred on the pivot axis (defined by bolt 100) of control lever 60, so as to be able to co-operate with the first pair of spaced formations 120, 122 carried by the control lever.

The structure of control lever 60 is shown in Figures 5 to 8 and comprises a shank portion 132 formed with an aperture 134 to receive bolt 100, a central portion 136 which is curved to avoid contact with blanking roller 70, and a handle portion 138.

Formations 120, 122 are located between the handle portion 138 and central portion 136 of lever 60. The lever itself is formed of sheet metal, and the formations 120, 122 are formed by bending projecting tapering portions of the sheet metal, through one right angle.

As can best be deduced from Figure 7, the said projecting portions of the sheet metal of control lever 60 are. before being bent into formations 120, 122, of unequal lengths. However they are bent at positions along their lengths so as to project laterally of the control lever by equal distances and so as to define a slot 140 between them to receive formations 124 to 130 on housing 46, as will be explained more fully below.

As shown in Figure 8, shank portion 132 of control lever 60 includes a cranked portion 142. The sheet metal of the control lever is itself inherentlv springy, and the angle between cranked portion 142 and the remainder of shank portion 132 is such that formations 120,122 are resiliently biased against the formations 124 to 130 on housing 46.

The formations 120 and 122 on control lever 60 and the formations 124 to 130 on housing 46 are proportioned and spaced so that each of the four formations 124 to 130 can fit one at a time between the formations 120 and 122, thereby providing four adjusted positions of the control lever relative to housing 46. Furthermore the formations 120 and 122 can jointly fit between each pair of consecutive formations on housing 46 (124 and 126,126 and 128, 128 and 130) thereby providing three more (giving a total of seven) adjusted positions of the control lever relative to housing 46, these positions being obtained with only four formations on the housing.

The seven selectable positions of control lever 60 provide seven corresponding posi- tions of flap 92 relative to fluted roller 62.

The appropriate setting is chosen by a farmer having regard to the size of the seed or fertilizer particles to be metered. The flap setting is not itself intended to be used as a means of adjusting the rate of seed or fertilizer flow.

The general principle of the invention is illustrated somewhat diagrammatically in Figures 9,10 and 11, in which there are shown a first pair of spaced formations 144, 146 and a second pair of formations 148, 150. The formations of each of these pairs are proportioned and spaced firstly so that each formation 148 and 150 of the second pair can fit one at a time (see Figures 9 and 10) between the formations of the first pair (l44 and 146), thereby providing two adjusted positions. Secondly, the first pair of formations 144. 146 can jointly fit between the second pair of formations 148,150 (as shown in Figure 11) thereby providing a third adjusted position.

In use, the metering mechanisms 20 and 22 meter seed and fertilizer respectively from hopper compartments 38 and 40 to the furrows opened by coulters 26.

Drive shafts 64 are set by the farmer before commencing work by means of a hand operated lever mechanism (not shown) which can shift the shafts and the fluted rollers 62 and the blanking rollers 70 mounted thereon axiallv. Such axial movement changes the rate of supply of particulate material by the metering mechanism.

When the blanking rollers are positioned between side walls 50, 52 of housing 46 with the fluted roller outside the housing the rate is zero, and when fluted roller 62 is fully exposed to the particulate material and extends between the side walls with the blanking roller outside, the rate is a maximum. The rate is steplessly variable between these limits.

Each tongue 92 of the metering mechanism is set by means of its control lever 60 according to the particle size of the seed or fertilizer being metered. Of course, all the seed metering mechanisms are set with a common tongue position and likewise for the fertilizer metering mechanisms (though probably with a different tongue position from the seed mechanisms). For this purpose the seed metering mechanisms (and likewise the fertilizer metering mechanisms) are mounted on the drill in a line extending transverse to the direction of forward movement of the drill and the control levers 60 project therefrom so as to be all simultaneously visible when the line of said mechanisms is viewed endwise. This enables a control lever which is not at the desired common setting to be instantly visually identified.

In the above embodiment, the metal components of the metering mechanism (housing 46 and control lever 60) are coated with a plastics material, for example, nylon (lever 60 being in a bright colour such as yellow or white).

More of the other components of the metering are moulded from nylon. This inclues gate member 58 including flap 92, sleeve members 96, 98, fluted roller 62 and blanking roller 70.

The above-described embodiment of the invention has the advantage that precise control of flap 92 is achieved without the use of a common flap control shaft. Furthermore the precision of control is achieved without using high tolerance components in, for example, the interengaging formations on the housing and the control lever.

It would of course be possible to provide a formation on the control lever for engagement with a component on the housing formed by a precision moulding technique or by machining and giving seven adjusted positions of the control lever. However such a component would add significantly to the cost of the metering mechanism whereas the four pressed-out formations in the above embodiment do not add any appreciable cost at all to the assembly.

Furthermore whereas in the above embodiment any chosen position of the control lever is easily identifiable visually e. g. as "between the second and third formations" or"over the fourth formation", where seven or more formations are used it is more difficult to visually identify a desired position except by counting, since the sheer number of formations tends to confuse the eye. That is to say, because the invention provides 2n-1 adjusted positions from n formations on the housing, less formations are needed and therefore setting the control member is a simpler matter.

Among modifications which could be made in the above embodiment without departing from the scope of the invention are the use, in place of fluted roller 62, of a rotatable metering member having outward lv projecting pegs and the use of multiple formations on control lever 62 and only two formations on housing 46.

Claims (14)

WHAT WE CLAIM IS:

1. A mechanism for metering particulate material comprising : a movable gate member ; and a manually-operable movable control member connected to said gate member characterized by a first pair of spaced formations carried by the control member; a second pair of spaced formations; structure carrying the second pair of spaced formations at a position so that they can co-operate with the first pair of said formations; and the formations of each of said pairs of spaced formations being proportioned and spaced firstly so that each formation of one of the pairs can fit, one at a time, between the formations of the other pair, thereby providing two adjusted positions of the control member relative to said structure, and secondly so that said other pair of spaced formations can jointly fit between said one pair of formations, thereby providing a third adjusted position of the control member relative to said structure.

2. A mechanism according to claim 1 characterized in that a total of at least three formations are provided on said structure carrying the second pair of spaced formations.

3. A mechanism according to claim 2 characterized in that said structure carrying the second pair of spaced formations is a housing in which the movable gate member is mounted and in which a rotatable metering member is mounted to co-operate with the gate member.

4. A mechanism according to claim 3 characterized in that the rotatable metering member is in the form of a fluted roller.

5. A mechanism according to claim 3 characterized in that the rotatable metering member has a series of outwardly-projecting pegs for engagement with particulate material.

6. A mechanism according to any of claims 3 to 5 characterized in that the manually operable movable control member is pivotally mounted on the housing and that the formations provided on the housing are located on an arc of a circle centred on the pivot axis of the control member.

7. A mechanism according to any of the preceding claims characterized in that the formations of at least one of said pairs of formations are formed by being punched or stamped out of sheet metal.

8. A mechanism according to claim 7 characterized in that the shape of each formation of said one pair of formations is a semi-circle.

9. A mechanism according to any of the preceding claims characterized in that the control member is formed of sheet metal and the formations on the control member are formed by bending projecting portions of the sheet metal.

10. A mechanism according to claim 9 characterized in that said projecting portions are, before being bent, of unequal lengths but are bent at positions along their lengths so as to project laterally of the control member by equal distances and so as to define a slot between them to receive one formation of said second pair of formations.

11. A mechanism according to any of the preceding claims characterized in that the control member is formed of springy material and is shaped and mounted so as to resiliently bias the pair of formations thereon towards the other pair.

12. A mechanism according to any of the preceding claims characterised in that said formations are formed of metal coated with a plastics material.

13. A mechanism for metering particulate material constructed and arranged substantially as described herein and as illustrated in Figures 2 to 8 of the accompanying drawings.

14. A planter or drill comprising a series of mechanisms as claimed in any of claims 1 to 13 characterized in that said mechanisms are mounted on the planter or drill in a line extending transverse to the direction of forward movement of the planter or drill, and that the control members of said mechanisms project therefrom so as to be all simultaneously visible when the line of said mechanisms is viewed generally endwise.