SE1651112A1 - Suspension device for mounting of a work apparatus on a vehicle - Google Patents

Description

10 15 20 25 30 35 forces are large, the ploughshare may either cut down into the underlying surface and damage both the plough and the surface. At the same time, this can exert forces on the carrier that damage its strength properties in that the front wheels of the carrier/vehicle lose their road grip. Existing plough suspension devices do not have sufficient movement and degrees of freedom to allow the plough travel relative to the underlying surface such that it gives sufficient control/degrees of freedom about six axes, i.e., movement along three linear axes and rotation about three axes.

Similar considerations apply also as regards, e.g., snow blowers or general work implements that are to follow the underlying surface and that are mounted to the front of a vehicle.

On earlier plough lifts, i.e., devices used to fasten the implement to a vehicle, the ploughs have a tendency to hang to one side when the plough is lifted. The reason for this is that the swinging movement is designed as a part of the swivel function of the plough, which causes unstable swinging.

General description of the invention The object of the present invention has in general been to eliminate or at least reduce the disadvantages of the prior art as mentioned above.

It has further been an object to improve an implement's possibility to travel across the underlying surface when it is used to clear a substance such as, for instance, SHOW.

It has also been an object to achieve a stable position of the tool when it is lifted from the surface.

These objects are achieved with a suspension device for an implement as defined in claim l. Additional features of the suspension device are defined in dependent claims 2-1 l.

The invention will be explained below with reference to the embodiment that relates to snowploughs. However, the suspension device according to the invention can also be used for other implements that are carried by a vehicle and are to follow the contours of the ground whilst they are subjected to both vertical and horizontal load forces during use as described above.

According to the present invention, a new type of suspension device has been designed for such tool/implements, for example, a snowplough suspension device, which provides unique properties with a view to the ability of the tool/plough to follow the underlying surface, gives flexible movement without the push/thrust forces together with the varying surface resulting in large, varying vertical forces on the carrier/vehicle. At the same time, this allows control of the ground pressure whilst having a stable construction when the implement/plough is lifted from the surface. Another advantage of the suspension device according to the present 10 15 20 25 30 35 invention is that by manipulating the suspension device, it Will be possible to raise or lower the forward edge of the implement/plough more than the rear edge of the implement/plough when it is raised, or when it passes over irregularities in the surface, e.g., speed humps.

By “larges forces” in meant, in this connection, forces that have sufficient strength to damage elements associated with the work implement, such as the implement itself and/or the vehicle and/or the suspension device by which the tool is supported. Such forces are therefore related not only to one of these elements, but usually to two or more of them. Such damage can be related to, inter alia, the strength of the material that is used in the suspension device and the implement, the robustness of the construction of the implement and/or the suspension device and/or the operating characteristics of the implement, the suspension device and/or the vehicle.

The plough suspension device according to the invention comprises rods of different length and direction, and which are mounted in spherical bearings that provide stability and ?exibility beyond what existing and known solutions for plough suspension devices have had to date.

Accordingly, there is provided a suspension device for mounting a tool/implement on a vehicle, the suspension device comprising: - a mounting frame for securing the suspension device on the vehicle; - an attachment frame for attachment of the work implement; - at least two lower arms which at their ends are attached to respectively the mounting frame and the attachment frame; - at least two upper arms which at their ends are attached to respectively the mounting frame and the attachment frame.

Each of the at least two lower arms is fastened to the mounting frame by a spherical bearing and to the attachment frame by a spherical bearing, and each of the at least two upper arms is attached to the mounting frame by a spherical bearing and to the attachment frame by a spherical bearing. As a spherical bearing allows rotational movement about all axes, the result of fastening all the arms that connect the mounting frame and the attachment frame by spherical bearings at both ends of all the arms, is that the tool is given especially good properties as regards following the surface across which the tool is pushed or drawn.

The at least two lower arms are preferably angled inwards from the mounting frame towards the attachment frame. Further, the distance between the attachment of the lower arms to the fastening frame can be greater than the distance between the attachment of the lower arms to the attachment frame. The upper arms are preferably shorter than the lower arms. 10 15 20 25 30 35 The suspension device can further comprise a torsion bar for controlling the swinging movement of the attachment frame and to centre the toolwhen it is lifted from the surface. Both ends of the torsion bar are preferably fastened to the attachment frame. In an embodiment, the torsion bar can comprise two end portions that extend backwards from the attachment frame and a centre portion that eXtends between the two end portions.

The mounting frame may comprise two fixing plates for securing the suspension device to the vehicle. The mounting frame can also be equipped with other types of attachment depending on corresponding attachments with which the vehicle is equipped. There are different standard brackets in use (Norwegian Public Road Administration, DIN standard, Volvo BM etc.), and therefore a type must be chosen depending on the vehicle to which the suspension device is to be secured.

The suspension device can further comprise a system for controlling vertical forces and controlling the lifting height of the attachment frame. The system preferably comprises a rod which at a first end is secured to the mounting frame at a first attachment point and at a second end is secured to the mounting frame at a second attachment point such that the rod has a substantially upright position. The first attachment point is preferably adjustable for regulating the ground pressure of the tool and for controlling the lifting height of the tool when a fixed snowplough bracket is used.

The solution that the suspension device according to the present invention represents has a plurality of degrees of freedom including swinging, where swing motion is obtained without using a conventional swing bolt. The solution reduces the danger of underrun and the variation in the vertical forces as a consequence of thrust forces and variations in height differences. This results in more stable pressure on the carrier°s steering axle, which in turn gives safer driving and less danger of incidents and accidents.

Smaller vertical forces mean that the plough is not forced down into surface beyond need, which results in it being easier to push, lower fuel consumption and more efficient snow clearing.

The great flexibility that is incorporated into the suspension device according to the invention means that the plough will follow the surface better, such that the result of the clearing by the plough is better without a “double run”, which in turn results in efficient snow clearing.

On a number of earlier plough lifts, the ploughs have had a tendency to hang to one side when the plough was lifted. The reason for this was that the swinging movement was designed as a part of the swivel function of the plough, which resulted in unstable swinging. 10 15 20 25 30 35 The suspension device according to the present invention also solves the problem seen with earlier plough lifts where the ploughs have had a tendency hang to one side when the plough was lifted because it is constructed of independent rods arranged systematically and balanced by a double-acting torsion bar pos 3.

To obtain improved control of the movement of the work implement/plough, one of the main points about the suspension device according to the invention is that the lower rod is longer than the upper rod. It is thus preferred that the length ratio between the upper rod and the lower rod is such that the upper rod is shorter than the lower rod, and preferably the lower rod is between 1 to 3 times longer than the upper rod, more preferably between 1 to 2 times longer than upper rod 1, for example, between 1 to 2.5 or between 1 to 1.5, such as 1.5, 1.75, 2, or 2.25 times longer than upper rod 1.

Brief description of the figures A non-limiting embodiment of the present invention will now be explained in detail below with reference to the attached figures, wherein: Figure 1 shows a three-dimensional partial front view of an embodiment of a suspension device according to the present invention assembled with a V-plough.

Figure 2 shows a three-dimensional partial rear view of the plough suspension device as shown in Figure 1 and assembled with the same V-plough as in Figure 1.

Figure 3 shows a top view of the plough suspension device that is shown in Figures 1 and 2, assembled with the same V-plough as shown in Figures 1 and 2.

Figure 4 shows a vertical section through the plough suspension device which is shown in Figures 1-3, assembled With the same V-plough as shown in Figures 1-3.

Detailed description of the invention An embodiment of a suspension device for mounting a tool/implement on a vehicle is shown in the attached figures. It should be noted that the same reference numerals are used in all the figures to designate the same technical features.

The figures show a suspension device 30 according to the present invention. The suspension device 30 comprises a mounting frame 17 for securing the suspension device to a vehicle (not shown) and an attachment frame 6 to which a tool /implement 12 can be attached. In the figures, a snowplough is shown attached to the attachment frame 6.

The attachment frame 6, which is shown in the figures, comprises a first attachment 8 for attaching the snowplough and a second attachment 9 for attaching a first rod 13 and a second rod 14. Both rods 13, 14 are fastened to the snowplough 12 at their respective second ends. 10 15 20 25 30 35 40 The mounting frame 17 comprises a plurality of transverse bars 18 and vertical bars 19. The vertical bars also include fixing plates 2 on the sides of the mounting frame.

The fixing plates 2 that are shown in the figures are illustrated with standard fastening hooks 21 and fastening holes 22 for attachment to the vehicle. Depending on what type of attachment the vehicle has, the attachment frame 17 can be provided with different types of standardised devices for fastening the suspension device to the vehicle. This may be an attachment on the carrier vehicle such as, for example, Norwegian Public Roads Administration, DIN standard, Volvo BM, 3 point or other alternatives.

Between the attachment frame 6 and the mounting frame 17 are arranged two heavy-duty bottom arms 5, attached by spherical bearings 24 at the ends and preferably angled inwards to take thrust and lateral forces. The bottom arms 5 are long in order to reduce variation in vertical forces in the carrier vehicle as a consequence of push/thrust forces and differences in height, i.e., direction of the thrust line through bottom arms 5, seen from the side, when there are substantial irregularities and/or changes in height in the surface. By “long” is meant in this connection a length that is in relation to the outer ends of the implement supported by the suspension device such that the bottom arms 5 run from the centre of the suspension device to an outer edge of the implement supported by the suspension device.

Further, two heavy-duty top arms 1 are positioned in the direction of travel between the attachment frame 6 and the mounting frame l7 to take torsional forces from the implement/plough and reduce the vertical forces as a consequence of the thrust forces, and thereby prevent “overrun”. These top arms 1 are fastened to respectively the mounting frame 17 and the attachment frame 6 by a spherical bearing 24 at both ends so as to be able to handle swinging movements. The top arms 1 are preferably substantially shorter than the bottom arms 5 in order to give good following properties on uneven surfaces, and to give good lifting properties when the implement/plough is lifted.

The suspension device 30 further comprises a torsion bar 3 which restrains and controls swinging motion and centres the implement/plough when the implement/plough is lifted from the surface. This torsion bar 3 is supported in such a way that it has a two-way action (double-acting), and at the same time the solution has the same functionality regardless of the lifting height of the plough (the direction of the top arms seen from the side). The torsion bar 3 as shown in the figures, comprises a first end 28 and a second end 29. Both ends 28, 29 are fastened to the attachment frame. The torsion bar 3 may further be fastened to the mounting frame, for example, to the fixing plates 2, or to the top arms 1. ln the centre of the plough suspension device is arranged a system 4 for regulating and controlling, i.e., reducing or increasing, vertical forces (ground pressure), and 10 15 20 for regulating and controlling the lifting height of the implement/plough When a fixed snowplough bracket is used (e.g., Norwegian or German standard snowplough bracket).

The structure of the system 4 is so configured that the space between the carrier/vehicle and the implement/plough is optimally utilised, such that the distance to the toolis as small as possible. In this case, it is the plough”s pivoting angle that provides the basis for the distance between implement/plough and carrier vehicle. Small distance means less torque arm in towards the carrier vehicle, and the carrier/vehicle has better “grip” on the implement/plough.

As shown in the figures, the attachment frame 6 is provided with a fastening element 7 whilst the mounting frame 17 is provided with fastening element 20. The fastening element 20 is adjustable in height as indicated in the figures. The system 4 further comprises a rod 26 which at one end is rotatably fastened to the fastening element 7 on the attachment frame 6 and at the other end is rotatably fastened to the fastening element 20 on the mounting frame 17.

Lastly, it should be noted that the embodiment shown in the figures is only an example of how a suspension device can be configured in practice and a person of skill in the field will understand that different features of the invention, such as the mounting frame and the attachment frame, could be configured in many different ways depending on the type of tool that is fastened to the attachment frame and the vehicle to which the mounting frame is secured, requirements of strength and rigidity of the suspension device and other factors.

Claims (7)

10 15 20 25 30 PATENT CLAIMS 1. A suspension device for mounting a work implement to a vehicle, which suspension device comprises: - amounting frame for securing the suspension device to the vehicle; - an attachment frame (6) for attachment of the work implement; - at least two lower arms (5) which at their ends are fastened to respectively the mounting frame and the attachment frame; - at least two upper arms (1) which at their ends are fastened to respectively the mounting frame and the attachment frame, wherein each of the at least two lower arms (5) is attached to the mounting frame by a spherical bearing and to the attachment frame (6) by a spherical hearing, and that each of the at least two upper arms (1) is attached to the mounting frame by a spherical bearing and to the attachment frame by a spherical bearing, characterised in that the at least two lower arms (5) are angled inwards from the mounting frame towards the attachment frame (6) such that the distance between the attachment of the lower arms to the mounting frame is greater than the distance between the attachment of the lower arms to the attachment frame, that the at least two upper arms are positioned in the direction of travel and that the at least two upper arms (1) are shorter than the at least two lower arms (5). A suspension device according to claim 1, characterised in that the suspension device comprises a torsion bar (3) for controlling the swing motion of the attachment frame (6) and for centring the tool when it is lifted from the surface. A suspension device according to claim 2, characterised in i n that both ends of the torsion bar (3) are fastened to the attachment frame (6). A suspension device according to claim 2 or 3, characterised in that the torsion bar (3) comprises two end portions that extend backwards from the attachment frame and a centre portion that extends between the two end portions. A suspension device according to one of the preceding claims, characterised in that suspension device comprises a system (4) for controlling vertical forces and controlling the lifting height of the attachment frame.

6. A suspension device according to claim 5, characterised in that the system (4) comprises a rod that at a first end is fastened to the mounting frame at a first attachment point and at a second end is fastened to the attachment frame (6) at a second attachment point such that the rod has a substantially upright position.

7. A suspension device according to claim 6, characterised in that the first attachment point is adjustable for regulating the ground pressure of the tool and for controlling the lifting height of the tool When a fixed snoWplough bracket is used.