WO1999032729A1

WO1999032729A1 - Snowploughing unit with foldable cutters

Info

Publication number: WO1999032729A1
Application number: PCT/SE1998/002068
Authority: WO
Inventors: Greger Ekenberg
Original assignee: Hysab Ab
Priority date: 1997-12-05
Filing date: 1998-11-17
Publication date: 1999-07-01
Also published as: SE9704534D0; SE521248C2; AU1355599A; SE9704534L

Abstract

Snowploughs known as V-ploughs are provided with a point and each blade (1, 2 and 3, 4, respectively) is provided with a pivotable foldable cutter. Such V-ploughs may cause damage to the snow-covered ground beneath. This is avoided according to the present invention in that, upon encountering an obstacle (22) on the ground, a folding edge (2 and 4, respectively), besides being pivoted, is also displaced outwards from the plough blade (1 and 3, respectively) and in that a spring system (13) returns the cutter (2 and 4, respectively) to its starting position (Fig. 7) when the obstacle (22) has been passed.

Description

SNOWPLOUGHING UNIT WITH FOLDABLE CUTTERS

The present invention relates to a snowploughing unit. Such a unit can be mounted on various types of motor vehicles, e.g. tractors. The unit may consist of a single inclined blade which blade may be provided at its lower edge with a foldable cutter. This cutter has a function to fulfil when the plough encounters an object protruding from the ground which is covered by a layer of snow. The foldable cutter is folded backwards so that the plough can pass without disturbance. In certain cases it may be desirable to have two inclined plough blades which form a point. Such plough blades are usually termed V-ploughs. It is also desirable in these plough units for each plough blade to have a foldable cutter. However, when the plough unit encounters a terrain obstacle, the cutter cannot be folded sufficiently far back again since the inner edges of the two cutters come into contact with each other. This is a considerable drawback inasmuch as, when the vehicle encounters an obstacle it may be retarded, thereby injuring the driver.

The object of the present invention is to provide a V-plough unit wherein the foldable cutter can be influenced in such a manner that the vehicle can without difficulty pass protruding obstacles that are not visible due to the snow covering them. In accordance with the invention this is accomplished in practice by each foldable cutter, when it encounters an obstacle, being given a retrograde turning motion and also an outwardly directed motion parallel with the plough blade. The upper part and foldable cutter of the plough blade cooperate with a spring system which is compressed at the outward movement of the cutter and is so designed that immediately the contact between the obstacle and the cutter has ceased, the spring system forces the cutter back to its starting position. The rear of the cutter is pivotably connected with one end each of two rods, the other ends of the rods being journalled in the upper part of the plough blade. These rods are connected to individual spring systems so designed that, upon lateral movement of the foldable cutter, they are compressed and strive to return the cutter to its starting position in the absence of obstacles on the ground. The present invention will be described in more detail with reference to the accompanying drawings in which

Figures 1 to 3 show schematically from the side three different situations in which a foldable cutter is cooperating with an obstacle,

Figures 4 to 6 show schematically the V-plough seen from above, Figures 7 to 9 show a V-plough unit in three different positions, and Figures 10 and 11 show a plough blade with accessories.

Figures 1-3 show a plough blade seen from the side, the upper part of which is designated 3, and where a foldable cutter arranged at the lower end of the upper part is designated 4. In Figure 1 said foldable cutter encounters a terrain obstacle 22. Figure 2 shows how the foldable cutter 4 is influenced by the obstacle and Figure 3 shows how the cutter passes the obstacle 22. Figures 4-6 show a V-plough unit, seen from above, in the three different situations according to Figures 1-3, where it is clear how the foldable cutters 2 and 4 are folded and displaced outwards during passage of a terrain obstacle 22.

Figures 7-9 show a road plough with upper parts 1 and 3, foldable cutters 2 and 4 and retaining members 5 and 6 in all three positions to which the V-plough unit can be subjected according to Figures 1-3.

Figure 10 shows a plough blade 3 with foldable cutter 4, in which the cutter 4 assumes its starting position, and Figure 11 shows the same plough blade as in Figure 10 but where the foldable cutter has been affected by a terrain obstacle and where the cutter has acquired both a pivoting and an outwardly directed movement. The upper part 3 of the plough blade is provided at its lower edge with two flanges 9 and 10 constituting attachment means for a shaft 8. The cutter 4 is provided with a transverse flange 7 to which two flanges 11 and 12 with openings are welded, the openings being designed for passage of the rod 8 so that the cutter is pivotable about the shaft 8. A helical spring 13 is arranged between the flanges 11 and 12. One end of the helical spring is in contact with the flange 11 , while part of the upper part 3 is in contact with the right-hand end of the spring so that, upon displacement to the right, the spring will be compressed and will endeavour to move the cutter 4 back to its original position. The cutter 4 is provided close to its ends with two transverse flanges 14 and 18, in turn provided with journalling units 15 and 19, respectively for the ends of two rods 16 and 20. The two bearings 15 and 19 may be of ball-and-socket type. The other ends of the rods 16 and 20 are journalled in a unit 6 with a longitudinal part and two transverse parts, a rectangular passage thus being formed for the upper ends of the rods 16 and 20. Each rod 16, 20 is provided with a helical spring 17, 21, respectively. When the cutter 4 assumes its starting position, both rods 16 and 20 are inclined in relation to the two side edges of the upper part and the helical springs 17 and 21 are uncompressed. When the cutter 4 is folded upwards and moves in outward direction, the springs 17 and 21 will be compressed and the two rods 16 and 20 will be substantially parallel with the edges of the plough blade.

Considering Figures 7-9 now, the plough blade 1-2 will be identical to the plough blades described in Figures 10 and 11.

It is thus clear from the above that when a V-plough encounters a terrain obstacle that may be covered in snow, the obstacle with cause a turning movement and also an outwardly directed movement of the cutter, whereupon the spring systems 13 and 17 and 21 will be compressed upon the outward movement and will return the cutters 2 and 4 to starting position when the blades are no longer in contact with the obstacle.

Claims

1. A snowploughing unit such as a V-plough with two blades (1,2 and 3, 4) forming a point, each blade (1, 2 and 3, 4, respectively) having an upper part (1 and 3, respectively) which is provided at the lower edge with a foldable cutter (2 and 4, respectively) that is pivotably journalled at the lower edge of the upper part (1 and 3, respectively), characterized in that the folding edge (2 and 4, respectively) of each blade (1, 2 and 3, 4, respectively) is so journalled as to be displaceable outwards from its cooperating upper part (1 and 3, respectively) from a starting position in which the outer edges of the upper part (1 and 3, respectively) coincide with the outer edges of the folding cutter (2 and 4, respectively) and in that the cooperating upper part (1 and 3, respectively) and the cutter (2 and 4, respectively) are influenced by a spring system (13) which is compressed upon displacement outwards and which strives towards displacement back to said starting position.

2. A snowploughing unit as claimed in claim 1, characterized in that each cutter (2 and 4, respectively) has an inwardly directed flange (14 and 18, respectively) close to its end, at which flange (14 and 18, respectively) a bearing is arranged, preferably in the form of a ball-and-socket joint (15 and 19, respectively), for one end of a rod (16 and 20, respectively), the other end of which is journalled in the upper part (3), and in that the rod (16 and 20, respectively) is influenced by a spring system (17 and 21, respectively) which is tensioned upon outward displacement of the cutter (4) and which strives towards displacement back to the starting position of the cutter (4).