GB2048702A

GB2048702A - A fodder mixing wagon

Info

Publication number: GB2048702A
Application number: GB8015083A
Authority: GB
Original assignee: Bayerische Pflugfabrik GmbH
Current assignee: Bayerische Pflugfabrik GmbH
Priority date: 1979-05-08
Filing date: 1980-05-07
Publication date: 1980-12-17
Also published as: DE2918519C2; DE2918519B1

Abstract

A fodder mixing wagon comprises a storage hopper 1 having steeply inclined side walls 2, 2' in which a plurality of mixing screws 3, 4 and 4' with closed screw surfaces are disposed substantially horizontally and are mounted to enable them to be driven rotationally, each mixing screw having its circumference located immediately proximate to a wall of said storage hopper, characterized in that said mixing screws are provided with recesses 15 at regular intervals along the circumference of the screw surfaces thereof. <IMAGE>

Description

SPECIFICATION A fodder mixing wagon This invention relates to a fodder mixing wagon, comprising a storage hopper having steeply inclined side walls in which a plurality of mixing screws with closed screw surfaces are disposed substantially horizontally and are mounted to enable them to be driven rotationally, each mixing screw having its circumference located immediately proximate to a wall of said storage hopper.

Such a fodder mixing wagon is already known from German utility model 7,738,430. It has been found, however, that during the operation of such equipment the fuel requirements are much higher than would actually have been expected due solely to the mixing operation itself.

It was also found that, depending on the type and amount of special portions of the fodder, obstructions occur in the material to be mixed. For instance, when grass silage is used, this fodder jams between the screw surfaces and the adjacent wall of the storage container, thereby resulting in especially high frictional losses. Moreover, the fodder itself is undesirably subjected to mechanical stress and, in part, even to thermal stress due to heating. This jamming effect also varies when the two mixing screws adjacent to the side walls of the storage container rotate in the same direction so that the upturning side of the one mixing screw is above and of the other mixing screw below the line at which the circumferences of the screw surfaces of the mixing screws come closest to the side wall.

The object of the invention is to prevent this jamming effect of such mixing screws when mixing in particular fibrous material, thereby diminishing the fuel requirements and obviating the stress applied to the fodder without impairing the mixing operation.

This object is accomplished in accordance with the invention in that said mixing screws are provided with recesses at regular intervals along the circumference of the screw surfaces thereof.

This causes jammed mixing material to be released at regular intervals and allows it to move into the transport zone of the mixing screws.

The desired action is effected in an especially complete manner by positioning the recesses in a spaced relation amounting to at most half of the pitch of the screw surface.

It has proved to be advantageous as a rule to provide three or four recesses at regular intervals along the helix of the screw surface, the greater number being located at the site where the side wall encompasses the screw surfaces over a greater angular area.

In an advantageous development of the invention, friction is reduced and the mixing action is enhanced by designing the recesses to have a steeply inclined edge in respect of the direction of rotation, preferably an edge oriented radially relative to the screw axis, and at least one flat edge connecting internally thereto and returning to the circumference of said screw surface.

As measurements have shown, these measures have resulted in a reduction of the previous, very high peaks in the speed of the device and in the total torque requirements and thus a reduction of 25% in the expenditure of energy while maintaining the speed at a constant value.

Moreover, the required mixing time is reduced by about half and at the same time the mixing action has improved as a check of the equipment has verified.

An embodiment of the fodder mixing wagon according to the invention will be described in more detail in the description and is illustrated in the drawings, in which: Fig. 1 is a longitudinal section through a fodder mixing wagon; Fig. 2 is a transverse section through the fodder mixing wagon.

The fodder mixing wagon includes a storage hopper 1 with steeply inclined side walls 2, 2' in which a lower mixing screw 3 and two upper mixing screws 4, 4' are mounted in bearings 5, 5'; 6, 6' and 7, 7' horizontally in the longitudinal direction of the wagon so as to be driven rotationally. Said bearings are mounted on the front wall 8 and on the rear wall 9. The storage hopper 1 is placed on a wagon frame 10 which is equipped with a draught-bar 11 and a two-wheel undercarriage 12.

Adjacent to the front end of the mixing screw 3, conveyor belts 14, 14' are provided beneath the same on the left and right sides of the wagon.

These conveyor belts 14, 14' are lined with side walls and bottoms outside of the storage hopper and convey outwardly through openings 19, 19' in the side walls 2, 2' of the storage hopper 1.

The openings 19, 19' are adapted to be closed by slides 20, 20'. In order to close the openings 19, 19', the slides 20, 20' are moved downwardly by a single-acting hydraulic cylinder which is not shown in the drawing.

The fodder which is introduced is circulated and mixed by the three mixing screws which rotate in the same direction. The lower mixing screws includes discharging means 24 adjacent to the discharge openings 19, 19' which are mounted at the same time and which are adapted to be closed by the slides 20, 20'. The two upper mixing screws are provided with clearing rakes 25 in the rear section of the storage hopper.

All three mixing screws rotate in the same direction 21; the lower mixing screw 3, however, has a conveying direction opposite that of said upper mixing screws.

The mixing screws are provided in regularly spaced distances with recesses 1 5 on the circumference 22 of the closed screw surface 1 3.

Relative to the direction of rotation 21 of the mixing screws, these recesses 1 5 include an edge 1 6 which extends radially in respect of the screw axis as well as another flat edge 1 7 connecting internally thereto and returning to the circumference 22 of said screw surface 13. The recesses 15 are located on the circumference of the screw surface 1 3 in regularly spaced distances such that they appear four times per screw rotation when the hopper wall extends at least along one fourth of the screw circumference 22, whilst the recesses 1 5 are mounted on the circumference of the screw surface 13 only three times per screw rotation when the hopper wail extends along less than approximately one eight of the screw circumference 22.

Claims

1. A fodder mixing wagon, comprising a storage hopper having steeply inclined side walls in which a plurality of mixing screws with closed screw surfaces are disposed substantially horizontally and are mounted to enable them to be driven rotationally, each mixing screw having its circumference located immediately proximate to a wall of said storage hopper, characterized in that said mixing screws are provided with recesses at regular intervals along the circumference of the screw surfaces thereof.

2. A fodder mixing wagon according to claim 1, wherein said recesses are positioned with at most the spacing of half of the pitch.

3. A fodder mixing wagon according to claim 1, wherein in respect of the direction of rotation of said mixing screws, said recesses have a steeply inclined edge, preferably an edge oriented radially relative to the screw axis, and at least one flat edge connecting internally thereto and returning to the circumference of said screw surface.

4. A fodder mixing wagon according to claim 3, whernin the flat edge of said recesses which returns to the circumference of said screw surface extends perpendicularly to said steeply inclined edge.

5. Afodder mixing wagon substantially as hereinbefore described with reference to the accompanying drawings.