GB2230709A

GB2230709A - Farinaceous mixer

Info

Publication number: GB2230709A
Application number: GB9008319A
Authority: GB
Inventors: Barrie Dawson
Original assignee: Tweedy of Burnley Ltd
Current assignee: Tweedy of Burnley Ltd
Priority date: 1989-04-14
Filing date: 1990-04-12
Publication date: 1990-10-31
Anticipated expiration: 2010-04-12
Also published as: GB2230709B; GB9008319D0; GB8908436D0

Abstract

A mixing element is rotated in an anti-clockwise direction in order to urge farinaceous material downwardly by the helical mixing blades 26, 28, during mixing. In order to discharge mixed material the container 12 housing the mixing element is tipped about pivot shafts 32 until the rotational axis of the element extends downwardly, and the direction of rotation of the element is reversed such that the mixing blades urge the farinaceous material in the opposite direction relative to the rotational axis of the implement to that in which material is urged during mixing in order to assist in the discharge of material from the now tilted container. <IMAGE>

Description

FARINACEOUS MIXER.

The present Invention relates to a method of operating a farinaceous mixer and to a farinaceous mixer.

In a known method of dough mixing using apparatus as disclosed in U.K. Patent No. 1 035 314, a scroll plate is made to rotate in a mixing drum in which are mixed the ingredients for the bread. The scroll plate is made to rotate in a particular direction so as to push the dough downwardly towards the base of the drum during mixing.

Movement of the material in this downwards direct Ion during mixing provides an efficient mixing of the products.

In order to discharge the dough the drum is tipped, but continued rotation of the scroll plate encumbers this operation and acts to retain the material within the container.

According to one aspect of the present invention a method of operating a mixer of farinaceous material comprises rotating a mixing element in a first direction during mixing to urge farinaceous material in one dIrectIon, and then rotating the mixing element In a second direction to urge farinaceous material In another direction, opposed to the one direction, during discharge of the farinaceous material. Preferably the method includes re-orientating, for instance by tipping a mixing vessel of the far I naceous mater i a I , from when the material Is being mixed to when it is being discharged.

When the material is being discharged from the mixing vessel, the rotation of the mixing element In the second direction may cause farinaceous material to move towards a discharge opening.

During the mixing of the farinaceous material the rotational axis of the mixing element may extend upwardly, and durIng discharge of the farlnaceous material the rotational axis may extend downwardly.

Preferably the method includes changing the direction of rotation of the mixing element automatical ly.

The method may comprise urging far I naceous material towards one end of a vessel when the mixing element is rotating in the first direction, but urging farinaceous material towards the other end when the mixing element Is rotating In the second direction.

According to a second aspect of the present invention a mixer of far I naceous material Includes control means arranged to reverse the direction of rotation of a mixing element. The means to reverse the direction of the mixing element may comprise an electrical switching circuit. The control means may be arranged to alter the direction of rotation automat icaily. The mixing element may Include a plurality of blades which may comprise generally helical blades.

The invention also Includes a mixer of farinaceous material when used with a method as herein referred to.

The invention may be carried into practice in various ways, but various embodiments will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 Is a plan view of a mixer Including a first embodiment of a mixing element; Figure 2 is a vlew of the mixer of Figure 1 in the mixing position wlth the wall of the vessel partially cut away to reveal the mixing element; Figure 3 shows a mixer In the discharge position as viewed from along the direction of arrow A in Figure 2, and Figure 4 is a perspective view of a second embodiment of a mixing element.

Referring particularly to Figure 1, Inside the wall 12 of the mixer 5 is a mixing element 7. The mixing element 7 comprIses a plate 10 which is substantlally octagonal In shape, and has a central hub for mounting the rotor on the upper end of a driving shaft within a cylindrical chamber of the mixing machine (the chamber being indicated by chain dotted line 12). An axially short cyl Inder 14 is secured on the under side of the plate 10 concentric with the hub, and four radially disposed blades 16 also secured to the under side of the plate proJect outwardly from the cylinder 14 and beyond the octagonal periphery of the plate. Each blade projects from a position approximately midway along one of the flats of the octagon.The plate has triangular extensions or fillets 18 disposed between the projecting portions of the blades and the plate at the trailing sides of the blades In the sense of the direction of rotation of the mixing element during mixing.

A conical column 20 extends upwardly from the top surface of the plate, the column being concentric with the axis of rotation of the mixing element, and the base of the column having a dlameter approxlmately one quarter the distance across the flats of the octagon. Two top blades 22 and 24 are provided on the top surface of the plate, these top blades being arranged diametrically opposite each other, and each extending from the column to the periphery of the plate. Each top blade Is curved In plan vlew, and Joins the foot of the column In a radial plane which is just in advance of a corner of the hexagon Immediately In front of one of the radial blades 16 on the under side of the plate, and reaches the periphery of the plate at the corner immediately to the rear of that radlal blade.

A palr of scroll blades 26 and 28 are also provided fluxed to the column. Each scroll blade Is substantially helical and at Its lower end blends into one of the top blades 22 and 24. The angle of the helix alters, however, so that one portlon of each scroll blade (between the positions marked "x" and "y" In Figure 2) has only a small helix angle, and the parts on each side of this portlon have much larger helix angles. The direction of inci inatlon of each scrol I blade Is such that, as the mixing element rotates during mixing, material on the blade Is pressed downwardly by the scroll blades. In particular, during mixing, the portlons of small helix angle help to compact material on the plate.

An electric motor 30 drives the mixing element 7.

Figure 2 shows the mixer in the mixing position and the mixing element rotating In the antl-clocicwlse direction of arrow B. Dough Is forced downwards agalnst the plate 10 by the act ion of the scroll blades to provide the mixing actlon.

Referring to Figure 3 the mixer has been tipped about Its pivotal mountings 32 to a discharge position.

The mixing element rotates In the clockwise direction of the arrow C so that the scroll blades urge the dough towards the open end of the mixing drum.

The reversal of the rotation of the mixing element may be achieved automatically for instance elther after a predetermined time delay or Independence upon the orientation of the mixer.

The mixing element 34 shown in Figure 4 is arranged to be located In the same container 12 as that shown in Figures 2 and 3 and to extend to generally the same height as the element 7. Thus the top of the element is a considerable distance below the top of the container when in the upright mixing position.

In order to mlx farinaceous material, the implement is rotated in an anti-clockwise direction, when viewed In Figure 4, such that farinaceous material Is urged downwardly by the mixing blades 36 to give a good and efficient mixing action. During discharge, the direction of rotation is reversed and the blades 36 act to push the mixed material out of the container. The orlentatlon of the container and the control of the mixing element may be as descrlbed wlth reference to or as shown In the mixing element shown in Figures 1 to 3.

Claims

1. A method of operating a mixer of farinaceous material comprlsing rotating a mixing element In a first direction during mixing to urge farinaceous material In one direction relative to the rotational axis and then rotating the mixing element in a second direction to urge farinaceous material in another direction relative to the rotational axis, opposed to the one direction, during discharge of the mixed farinaceous material.

2. A method as claimed In Claim 1 including reorientating a container of farinaceous material from when the material is being mixed to when it Is being discharged.

3. A method as claimed in Claim 2 comprising tipping the container in order to reorientate the container.

4. A method as claimed In any preceding claim In which rotation of the mixing element in the second direction causes farinaceous material to move towards a discharge opening.

5. A method as claimed In any preceding claim In which, during the mixing of the farinaceous material, the rotational axis of the mixing element extends upwardly and, during discharge of the farinaceous material, the rotational axis extends downwardly.

6. A method as claimed In any preceding clalm comprising changing the direction of rotation of the mixing element automatically.

7. A method as claimed In any preceding claim comprising urging farinaceous material towards one end of a vessel, when the mixing element is rotating in the first direction, but urging farlnaceous material towards the other end when the mixing element Is rotating in the second direction.

8. A method of operating a mixer substantially as herein described with reference to, and as shown In Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings.

9. A farinaceous material mixer Including a rotatable mixing element and means for causing rotation of the mixing element in either rotational direction.

10. Apparatus as claimed in Claim 9 including control means arranged to reverse the direction of rotation of the mixing element.

11. Apparatus as claimed in Claim 10 In which the control means comprlse an electricai switching circuit.

12. Apparatus as claimed in Claim 10 or Claim 11 In which the control means are arranged to alter the direction of rotation of the mixing element automatically.

13. Apparatus as claimed in any of Claims 9 to 12 in which the mixing element Includes a plurality of blades.

14. Apparatus as claimed in any of Claims 9 to 13 in which the mixing element includes at least one generally helical blade.

15. Apparatus as claimed in any of Claims 9 to 14 in which the mixer includes a container which is movable between one position when material Is being mixed and another position where material Is being discharged.

16. A farinaceous material mixer substantial ly as herein described with reference to, and as shown in Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings.

17. A farinaceous material mixer as claimed in any of Claims 9 to 16 when used In a method of mixing farinaceous material as claimed in any of Claims 1 to 8.