GB1570061A

GB1570061A - Beater mill

Info

Publication number: GB1570061A
Application number: GB16859/78A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-04-29
Filing date: 1978-04-28
Publication date: 1980-06-25
Also published as: IT7849128A0; FR2388598A1; NL7804639A; DE2719266C2; PL206455A1; DE2719266A1; DK186478A; BE866538A; ES469311A1; YU101878A; AT356487B; PL114328B1; ATA303578A

Description

(54) BEATER MILL (71) I, JOHANN NAGY, a German citizen of Kleebergerstrasse 10, 8399 Kleeberg, West Germany, do hereby declare the invention for which I pray that a Patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a beater mill of the kind in which a rotor with beater arms on it rotates within a drum having an inlet shaft, a pivoting flap capable of obtruding into the inlet shaft being urged clear of the shaft by energy-storing means and being urged into the shaft, to restrict the flow of material to the drum, by means responsive to the quantity of flowing material.

Such a beater mill has already been proposed. In this mill a first flap has a pivoted curved plate with its centre of curvature on its pivotal axis, the plate being carried by two arms on a spindle. On the spindle there is a lever arm for receiving a weight that serves to provide a restoring force, and a further arm coupling this first flap to a second flap, which also pivots. The curved closure plate is provided with deflecting strips on that side which is towards the flow of materials to be ground, in such a way that in the event of a large flow of material the first flap is pivoted towards its closed position, to reduce the flow of material, against the restoring force of the weight.

The second flap, mounted on that side of the inlet shaft which trails in the direction of rotation of the rotor, is made of plate-like shape and is coupled to the first flap in such a way that on movement of the first flap away from that position of it which leaves the inlet shaft free, i.e. in a direction to obtrude into the shaft, the second flap is turned towards the first flap and moved into the path of the circulating flow of material in the drum.

This has the effect that the circulating material within the drum is thrown towards the mouth of the inlet shaft thereby additionally restricting the entry of further material.

A particular drawback of this previously proposed mill is that on alteration of the inflow of material it only reacts when the excessive or deficient quantity of material fed to the inlet shaft reaches the first flap, which is only after a complete rotation of the beater rotor. Furthermore it only reacts to a relatively large quantity of circulating material and even then only relatively insensitively.

It is therefore the aim of the invention to provide a beater mill of the kind stated in the introductory paragraph above which is still further improved, in particular with regard to the magnitude of the control range, the accuracy of the control and the speed of response to changes in the input of material, whilst maintaining a simple construction.

According to the invention, in such a mill the said flap is coupled to a second flap for simultaneous movement in such a way that when the first-mentioned flap moves in a direction away from the drum to obstruct the shaft the second flap swings clear of the path of material circulating within the drum and vice-versa.

Beater mills of the kind in question are employed chiefly in agriculture for the preparation of fodder. In this connection it must be borne in mind that the operating personnel are mostly non-technical and that therefore operation must be as simple as possible and furthermore no breakdowns or damage should arise as these would have to be dealt with by a trained man who is not always readily available in country districts.

This requirement is taken into account by the relatively simple construction of the beater mill according to the invention and further by the fact that the possibility of overloading and consequent damage to the driving motor, for example an electric motor, is reduced by the rapid speed of response to excessive quantities of material.

Another important point is that such beater mills have to pulverise effectively a wide range of materials and indeed also those that are difficult to pulverise, for example fibrous materials. This is achieved by the beater mill according to the invention because it not only has a wide range of control, so that even a small flow of material into the interior of the drum can be controlled, but also it is furthermore possible to control such a small flow of material accurately.

Finally, by virtue of the high speed of response and accuracy of control of the beater mill according to the invention, uniform grain size of the reduced material is achieved, as well as outstanding efficiency.

The invention is described by way of example in the following in conjunction with the accompanying drawing, the single figure of which shows a cross-section through a beater mill according to the invention.

Mounted in a drum 1 is a beater rotor which comprises a carrier or hub 3 mounted to rotate about an axis 2 and beaters 5 mounted on it, each able to swing about a pivot 4. The rotor is driven by an electric motor (not shown).

Each of the beaters 5 has on its free end three hardened impact members 6, by means of which it co-operates with deflecting strips 7 as the rotor turns in the direction of the arrow, these strips being mounted on the inside face of the drum 1 between an outlet shaft 8 and an inlet shaft 9.

The outlet shaft 8 is placed at one side of the drum 1, in fact on the same side as the inlet shaft 9. A sieve 10 is provided between the shaft 8 and the interior of the drum.

The inlet shaft 9 extends over the upper quadrant of the periphery of the drum which lies immediately downstream of the outlet shaft 8 (looking in the direction of rotation of the rotor) and comprises a passage 11 leading from a feed hopper 12 to the interior of the drum 1.

At the lower end of that side of the passage 11 which is nearest the outlet shaft, the upstream side there is a first pivoting flap 13 mounted on a spindle 14 which is parallel to the axis of rotation of the beater rotor 2. This first pivoting flap 13 is in the form of a flat plate.

At the other side of the inlet shaft 9, or rather of the passage 11, i.e. the downstream side, there is a second pivoting flap 15 which is likewise rotatably mounted by means of a spindle 16 about an axis parallel to that of the rotor 2, and is likewise in the drum 1. The second flap 15 is curved to an arc of a circle such that the concave surface is facing opposite to the direction of rotation of the rotor.

The second flap 15 is connected to a weight 17 forming energy-storing means to provide a restoring force. For this purpose a lever arm 18 is secured to the spindle 16 and carries the second flap 15, whilst there is another lever arm 19 on which the weight 17 is adjustably mounted.

Furthermore the second flap 15 is coupled to the first flap 13 to link their movements together. For this purpose a lever arm 20 is mounted on the spindle 14 with the first flap 13 and a lever arm 20 is secured to the spindle 16 on which the second flap 15 is secured by means of the lever 18. The arms 20 and 21 are connected together by a coupling link 22, the two ends of which are pivotally connected to the free ends of the arms 20 and 21. The coupling link 22 in its turn is made up of two arms of about the same length connected by a joint 23.

Ahead of the second flap 15 and at the downstream side of the inlet shaft 9 or rather its passage 11, there is a third pivoting flap 24 secured to a spindle 25 and thereby likewise rotatable about an axis parallel to that of the rotor 2. Like the first flap 13 the third flap 24 is also flat in the shape of a flat plate.

On the spindle 25, for coupling the third flap 24 to the first flap 13 and the second flap 15, there is a lever arm 26 of which the free end is pivoted to the coupling link 22 and in fact to the joint 23 between the two arms of the link 22.

With reference to the longitudinal sectional plane of the passage 11 of the inlet shaft that is parallel to the axis of the rotor 2, the spindle 14 is arranged offset away from the axis of the rotor 2 as compared with spindle 25 that carries the third flap 24.

The linkage 20, 21, and 26 is, like the arm 19 and the weight 17, mounted outside the drum 1. The spindles 14, 16 and 25 are rotatably mounted in the two side walls of the drum or rather in the two side walls of a radial extension 27 serving to receive in particular the second flap 15. In addition a fixed guide plate 28 is secured to the inside of the extension 27 and extends substantially tangential to the direction of rotation of the rotor, between the second flap 15 and the spindle 25 that carries the third flap 24.

Provided at the lower end of the hopper 12 there is a cut-off slide 29 by means of which the passage 11 of the inlet shaft 9 can be closed off when the mill is to be put out of action altogether.

In the drawing the three flaps 13, 15 and 24, the linkage 18, 20, 21, 22 and 26 and the arm 19 carrying the weight 17 are shown in full lines in that position in which the inlet passage 11 of the shaft 9 is fully open, i.e.

unobstructed. The first flap 13 extends radially away from its spindle 14 into the interior of the drum, i.e. into the path of material circulating in the drum, the second flap 15 has its lower portion directed towards the axis 2 of the rotor and the third flap 24 has its free end projecting upwards away from the rotor. Shown in broken lines is the other end position of the three flaps 13, 15 and 24 and the linkage 18, 20, 21, 22 and 26, that is to say the position in which the passage 11 of the shaft 9 is obstructed. The first flap 13 and the third flap 24 then extend almost perpendicular to the longitudinal axis of the passage 11 and the lower portion of the second flap 15 is swung away from the axis 2 of the rotor, the arcuate profile of the second flap 15 approaching a position in which it is concentric to the axis 2.

With the flaps 13, 15 and 24 in the positions shown in full lines the material to be ground can flow freely into the drum 1 and be reduced to powder in it. If the flow of material through the passage 11 of the shaft 9 and meeting the second, curved, pivoting flap 15 becomes too large it pivots this flap, against the action of the weight 17, away from the rotor to the position shown in broken lines, thereby causing the first and third flaps 13 and 24, arranged below the passage 11, to be pivoted into the closing position illustrated in broken lines, obstructing the passage 11 and reducing the flow of incoming material.

This happens as soon as the quantity of material reaching the interior of the drum through the inlet shaft 9 is larger than has been pre-set by corresponding adjustment of the weight 17; thus extremely rapid control of the entry of material to be ground is achieved.

Also with the parts in the positions shown in broken lines in the drawing, the third flap 24 is arranged offset inwards towards the axis 2 of the rotor, as compared with the first flap 13, with the first flap 13 extending in the direction of the circulating flow of material being ground, i.e. downstream, and the third flap 24 extending opposite to the direction of the flow i.e. upstream. The entry of material from the passage 11 is thereby further reduced in that circulating material from the drum is thrown towards the gap between the first flap 13 and the third flap 24, producing an obstruction to impede the incoming material.

The concave surface of the second flap 15, facing against the direction of flow of material, together with the guide plate 28, further ensures that even small departures from the pre-set inflow of material lead to pivotal movement of the second flap 15 and thereby to regulation of the material by means of the first flap 13 and the third flap 24. In this way the desired input of material is adjustable accurately within very narrow limits and this therefore further improves the accuracy obtained by the extremely rapid response.

On the downstream side of the free lower edge of the second flap 15, there is secured a plate 30 extending substantially parallel to it.

The plate 30 exerts a stabilising effect on the second flap 15, preventing it vibrating or fluttering.

Accurate adjustment of the input of material to be ground is desirable for several reasons. On the one hand a sudden, even though brief, excessive inflow of material can lead to overloading and consequent damage to the driving motor. Furthermore variations in the input of material cause variations in the size of the ground material, which not only acts against the desire for a grain size that is as uniform as possible but also, in the case where the input of material is too small, it leads to excessive reduction in size and consequently to a reduced efficiency of the mill, in that it is doing more work than is called for.

All these requirements and consequences certainly come into particular importance in the case of material that is difficult to pulverise, in particular fibrous material. Accordingly the extreme accuracy obtainable with the mill according to the invention in the control of the input of material, represents a significant technical advance.

In the drawing each beater 5 has three plate-shaped impact members 6 arranged spaced apart and parallel to one another. The three impact members 6 ar connected on each side to a pair of arms 31 which is pivotally mounted on the carrier 3 about the respective pivot 4. The members 6 of each beater 5 therefore define between them two mutually parallel clearance passages extending in the direction of the length of the beater arm.

When the rotor is turning these pairs of passages in the beaters 5 cause a flow of air which cools the material being ground.

The beater mill according to the invention is suitable in particular for pulverising agricultural products, for example cereal grains, peas, lentils, chestnuts, acorns and lucerne, and furthermore for reducing fibrous materials, in particular for the preparation of cattle fodder. In this connection as far as possible there should be no excessive heating of the material in the mill as a result of friction or the like, as this adversely affects the quality, in particular when the incoming material has already been treated with temperature-sensitive additives or where these are to be added directly after reduction.

Such additives are generally added primarily for veterinary purposes.

Furthermore in view of the abovementioned field of use, it is to be noted that the operation is as far as possible fool-proof, and damage through operator's errors are to a large extent eliminated. This is valuable because on the one hand the operating personnel generally have no technical knowledge or experience and on the other hand repairs in the agricultural field are generally expensive anyway on account of the long journey time involved. The mill is generally able to reduce equally well goods of various kinds and varying conditions, for example moist grains of maize which have a tendency to collect in lumps on the one hand and smooth snall polished grains of wheat on the other hand.

Even these requirements are fulfilled in the mill according to the invention, being fulfilled in fact in a simple manner but very effectively.

WHAT I CLAIM IS: 1. A beater mill in which a rotor with beater arms on it rotates within a drum having an inlet shaft, a pivoting flap capable of obtruding into the inlet shaft being urged clear of the shaft and into a position in which it projects into the path of material circulating in the drum by energy-storing means and being urged away from the drum and into the shaft, to restrict the flow of material to the drum, by means responsive to the flow quantity of flowing material, in which the said flap is coupled to a second flap for simultaneous movement in such a way that when the first-mentioned flap moves in a direction away from the drum to obstruct the shaft the second flap swings clear of the path of material circulating within the drum and vice-versa.

2. A mill according to claim 1 in which the drum has its axis horizontal and the inlet shaft opens into the interior of the drum in the upper quadrant of the periphery of the drum, immediately downstream of the outlet shaft looking in the direction of rotation of the rotor.

3. A mill according to claim 1 or claim 2 in which the first flap and the second flap are connected together by a mechanical linkage.

4. A mill according to claim 3 in which on each of the flaps is connected to a lever arm and the two lever arms are connected together by a coupling link.

5. A mill according to any one of claims 1 to 4 in which, looking in the direction of rotation of the rotor, ahead of the second flap and at the trailing edge of the inlet shaft there is a third flap pivoting about an axis this third flap being held by the energystoring means force in an end position in which it projects away from the circulating flow of material in the drum and is coupled to the second flap in such a way that when the second flap swings out of the path of circulating flow of material the third flap is moved away from its end position and into the path of circulating flow of material in the drum.

6. A mill according to claim 5 in which the third flap is connected to a mechanical linkage that connects together the first and second flaps.

7. A mill according to claim 6 in which a lever arm is provided on the third flap and is pivotally connected to a coupling link that couples together arms connected to the first and second flaps.

8. A mill according to claim 7 in which the coupling link comprises two arms connected together by a joint and the lever arm of the third flap engages that joint.

9. A mill according to claim 3 or claim 6 in which the mechanical linkage and the lever arm on the third flap, if present, are arranged outside the drum and the inlet shaft.

10. A mill according to any one of claims 1 to 9 in which that surface of the second flap which lies opposed to the direction of the circulating flow of material within the drum is concave.

11. A mill according to claim 10 in which the second flap is curved in the shape of an arc of a circle.

12. A mill according to any one of claims 1 to 11 in which on the side of the second flap which trails looking in the direction of rotation of the rotor there is a plate spaced from it and extending substantially parallel to it and extending beyond the free edge of the second flap.

13. A mill according to any one of the claims 5 to 9 in which the first flap and the third flap are flat.

14. A mill according to any one of claims 5 to 9 or 13 in which between the second flap and the axis of rotation of the third flap there is provided inside the drum a fixed guide plate which extends substantially tangential to the direction of rotation of the beater rotor.

15. A mill according to any one of claims 5 to 9 or 13 or 14 in which, with respect to the longitudinal central plane of the inlet shaft that is parallel to the axis of rotation of the rotor, the pivotal axis of the third flap is offset inwards towards the axis of rotation of the rotor as compared with the pivotal axis of the first flap.

16. A beater mill constructed and operating substantially as described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. mill according to the invention, being fulfilled in fact in a simple manner but very effectively. WHAT I CLAIM IS:

1. A beater mill in which a rotor with beater arms on it rotates within a drum having an inlet shaft, a pivoting flap capable of obtruding into the inlet shaft being urged clear of the shaft and into a position in which it projects into the path of material circulating in the drum by energy-storing means and being urged away from the drum and into the shaft, to restrict the flow of material to the drum, by means responsive to the flow quantity of flowing material, in which the said flap is coupled to a second flap for simultaneous movement in such a way that when the first-mentioned flap moves in a direction away from the drum to obstruct the shaft the second flap swings clear of the path of material circulating within the drum and vice-versa.