EP0656086B1 - Snowplough - Google Patents

Abstract

The snowplough described has a blade (1), which scrapes the snow up from the ground, and an upper plough element (2) with a flexible plate designed to deflect the stream of snow. The curvature of the flexible plate (3) can be adjusted by means of a mechanism (7.1, 7.2, 9, 11, 14, 40). The invention calls for the plate (3) to be held by the mechanism by means of a floating mounting (17). In this way, the plate (3) is not affected by direct internal stresses caused by temperature or other reasons. The flexible plate (3) is held at its upper and lower edge, the two edges being controlled so that they are always parallel to each other.

Description

Technical field

The invention relates to a snow plow with a the flow of the snow deflecting flexible plate which is adjustable with a mechanism in its curvature. The The invention further relates to a method for changing the Curvature of the flexible plate in a snow plow.

State of the art

A snow plow of the type mentioned is e.g. B. from the JP-Y-56 17 543, FR-A-1 254 965 or EP-A-0 365 436.

The advantage of variable plates is that one and the same snow plow in different working conditions can be used. This allows a reduction of the variety of types: Where previously several device types only one can now be made available Type are sufficient. Depending on the type of variability of the curvature can - based on the idea of variable curvature - the direction of snow flow can be set without the plow would have to be turned (see e.g. EP 0 365 436).

The plate to be deformed preferably consists of a elastic material. It will be special these days Plastic plates used. The problem now is that the plastic plate has a different coefficient of expansion than the metallic frame construction has and that the plate bulges undesirably when bent.

A snow plow with a flexible plate is known from US-A-5,079,866 which the curvature is adjusted by the fact that the upper edge with a Mechanism is pushed diagonally forward. The snow plow is on his open to both sides to different degrees. At the top edge the plate is held that it can avoid the pressure that occurs during plowing. The bottom of the The plate is firmly clamped.

Presentation of the invention

The object of the invention is to provide a snow plow at the beginning Specify the type in which the flexible resp. elastic Plate regardless of temperature changes and set Free from unwanted bulges and curvature Deformations.

The solution to the problem is defined by the features of claim 1. According to According to the invention, the plate is kept floating by the mechanism.

The essence of the invention is that the plate is given the opportunity evade internal tensions. With temperature changes or local It can shift loads (normal forces) in its holder.

The plate is held at its upper and lower edges, the two Edges are always held or guided parallel to one another by the mechanism. Unlike the snow plow according to EP-A-0 365 436, the plate does not become one subjected to uneven curvature. So viewed in vertical section is Curvature curve the same across the entire width of the plow.

The mechanism is designed so that the position and direction the upper edge of the plate when adjusting it is specified that the bending force is mainly local acts perpendicular to the plate. The normal forces (i.e. the Forces in the resp. parallel to the local plate level), the to a plate expansion resp. - compression (bulge in extreme cases) can lead through the correct "leadership" of the Avoided plate edge. Incidentally, normal forces are also largely avoided due to the floating storage.

It should be noted that for a clean guide, both the Position of the plate edge in the room as well as its direction must be defined. With a plate holder like this e.g. B. from EP-A-0 365 436 is known by the actuating mechanism an uncontrolled on the platemark Torque exerted to a locally inflated Load on the plate. In contrast, the Invention the bending moment in an optimal way on the plate transferred (no "kinking" of the plate edge).

The mechanism includes, for example, a two-lever system, where two levers of different lengths with each other spaced axes of rotation the position and direction of the specify the upper margin. With the two levers, the bracket of the upper plate edge not only in terms of position, but also be guided in the right direction. Instead of one Two-lever system is also a construction with cables conceivable.

A hydraulic system operates the levers of the two-lever system synchronously. For this purpose, they are advantageously on the same cylinder piston attached.

For optimal parallel guidance of the two plate edges there are at least two two-lever systems, each with at least one hydraulic cylinder can be actuated. The two Hydraulic cylinders are connected via flow dividers. Thereby can be prevented in particular in the case of unequal sides Load on the top of the plow in the transverse direction the positions of the hydraulic cylinders and thus the Change two-lever systems in the opposite direction can (e.g. open on the left and close on the right at the same time).

The ploughshare, which is arranged below the top of the plow and scrapes the snow off the ground. picks up, preferably has several, adjoining one another laterally, individually foldable elements. Because of their mobility they can avoid obstacles on the ground. Thereby, that several independently foldable elements are provided, the mass to be moved per element smaller.

The elements are stored in such a way that they can be hit to an obstacle - without lifting off the ground - around the impact point turn to a negative position then to jump over the obstacle. The swivel movement takes place not - as with the Tecnnik stand - around the top, but a horizontal one at a medium height Axis of rotation. So the top part of the element is moving - relative to the upper part of the plow - to the front and the lower to the rear behind. The foldable elements are preferably on one at rest essentially horizontal, vertical swiveling lever rotatably mounted. So the element can dodge up to a certain extent. Overall, that has As a result, the element has a large cushioning path.

The element is preferably with one above the connection between lever and element attacking cable in one positive rest position pulled. The cable pull includes a pulley and a more or less vertically aligned one Spring (especially a hollow rubber spring). The cable is less problematic than a tie rod, because jamming of the force-transmitting elements (rope instead of rod) do not occur can. Furthermore, the designer has more freedom when arranging the spring element (due to the force deflection through the role mentioned).

The lever pivotable in the vertical direction is preferred stored in eccentric bushes to fine-tune the Gap between the foldable element and the plow top to enable. In this way, e.g. B. Manufacturing tolerances or age-related changes will.

To adapt optimally to the local ground slope to be able to, the elements are small in the transverse direction tiltable. The corresponding bearings and joints of the elements resp. the horizontal lever arms have an elastic material, which is a wobble of the joint and thus - besides swiveling - also a slight sideways tilting of the element enables.

The method according to the invention for changing the curvature the flexible plate for a snow plow of the type mentioned Art is characterized in that the plate on two opposite edges always parallel in brackets is held and that the brackets when adjusting the curvature is guided in position and direction in such a way that the bending force is essentially only locally perpendicular to the Plate works.

From the following description and the entirety of Claims result in further advantageous embodiments and combinations of features of the invention.

Brief description of the drawings

Fig. 1

Eine schematische Darstellung des Pflugoberteils im Schnitt;

Fig. 2

eine Schnittdarstellung der erfindungsgemässen Plattenhalterung;

Fig. 3

eine schematische Darstellung der Pflugschar im Schnitt.

The invention will be explained in more detail below on the basis of exemplary embodiments and in connection with the drawings. Show it:

Fig. 1

A schematic representation of the upper part of the plow;

Fig. 2

a sectional view of the plate holder according to the invention;

Fig. 3

a schematic representation of the ploughshare in section.

Basically, the same parts are in the drawings provided with the same reference numerals.

Ways of Carrying Out the Invention

A snow plow according to the invention (cf. FIG. 1) has one Ploughshare 1, which scrapes the snow off the ground, and one Plow top part 2, which the snow to the side redirects. Apart from a gap 38, the front sides close of ploughshare 1 and plow head 2 flush with each other with the inclinations of the two front surfaces are coordinated (optimal snow flow).

The plow top 2 has a flexible, respectively. elastic Plate 3 made of plastic or other suitable material on. It is essentially rectangular and is attached to it top and bottom of a bracket of the in Fig. 2 shown floating type.

Along the entire upper edge 21 of the plate 3 is on a recess 20 is provided on its front edge, so that a Gradation is formed. At the back of the plate 3 (and set back with respect to the recess 20) several z. B. oval wells respectively. Recesses 22 are provided. The plate holder 17 has a z. B. triangular Profile 41 and a clamping rail screwed to the latter 39, which - spanning the upper edge 21 - in the recess 20 engages. For each recess 22 is on Profile 41 also formed a nose 23 which in the (corresponding) Recess 22 engages.

The floating storage now results from the fact that the Nose 23 not completely, but only the recess 22 partially filled and that the clamping rail 39 with their Not directly to the face through the recess 20 formed gradation bumps. The plate 3 can thus in Towards their local "plate axes" (i.e. towards the x and y axes) in the local plate plane) the bracket 17 respectively. between clamping rail 39 and profile 41 move resp. move. The nose 23 prevents that the plate 3 from the (by clamping rail 39 and profile 41 formed) can slide out. The floating one Storage prevents excessive normal forces (in the plate 3) can build.

Plow top 2 and ploughshare 1 are directly resp. indirectly supported on a transverse support beam 4. This is in turn on a (not shown Frame), which is used to open the snow plow in front to put on a vehicle.

On the support beam 4, several support elements are attached. One of which is shown in the figures and with the reference symbol 5 marked. The support element 5 projects among other things diagonally downwards and backwards away in a joint 6 one Support hydraulic cylinder 7.1. The piston 7.2 of the hydraulic cylinder 7.1 is on the one hand with a joint 8 a long-armed lever 40 and on the other hand - via one Transfer arm 9 - connected to a short-armed lever 11.

The lever 11 is rotatable about a pivot point 12, which arranged more or less centrally above the support beam 4 is. (The corresponding support structure is in the figures not shown.) He has two arms 11.1 and 11.2, those with the transmission arms 9 and 14 at their ends, respectively a knee joint 10 respectively. 13 form. The transmission arm 14 is via a hinge 15 with a plate holder 17 supporting head part 16 connected.

Arm 11.2 is longer than arm 11.1. It is also curved (concave from the plate), so when "closing" (position B) the plow head for the curved plate has enough space.

The two knee joints 10 and 13 are in the present example with respect to the pivot point 12 at an angle of approx. 110 to 120 degrees. Arm 11.1 also has a turning radius of about 15 cm and the arm 11.2 one of about 35 cm Transmission arms 9 and 14 are about 20 cm respectively. 15 cm long (Joint axis to joint axis).

The long lever 40 is mounted in the fulcrum 19, which e.g. B. 15 to 20 cm vertically below the pivot point 12 on Support element 5 is formed. The lever 40 is on the one hand via the joint 8 with the piston 7.2 and on the other hand a joint 18 is connected to the head part 16. The joint 18 has a turning radius of 60 to with respect to the pivot point 19 65 cm and the joint 8 such a 15 to 18 cm. Regarding Curvature of one arm and opening angle with respect the fulcrum 19, the lever 40 is similar like the lever 11.

The described two-lever mechanism is used for the curvature disc 3 to be adjusted by changing the (spatial) Position and direction of the plate holder 17. To a To ensure parallel guidance, the plate 3 of held two lever systems arranged side by side. The two two-lever systems are each operated by a hydraulic cylinder operated synchronously. The hydraulic system is like this interpret that the same positions also in different Load are observed. This can e.g. B. happen with a known flow divider, which the fluid exchange between the cylinders if necessary can prevent.

In Fig. 1 the plow top 2 is in the open position A. (solid lines) and in the closed position B (dashed lines).

In the open position, the piston 7.2 is fully retracted. The plate 3 has a slight curvature. Now the Piston 7.2 extended, then the levers 11, 40 to Pivots 12 resp. 19 rotated, the head part 16 after moved forward and according to the selected leverage ratios inclined forward to the closed position B.

Of course, any intermediate position can be done by the hydraulics can be set. How strong the plow top 2 must be opened or closed depends on the Driving speed, the snow mass to be removed desired throw distance and other conditions to be set by the user on a case-by-case basis.

Fig. 3 shows the ploughshare 1 together with the associated cushioning mechanism. The ploughshare 1 has a plate-shaped Swivel element 26 with a replaceable at its lower edge attached knife 24 on. The knife 24 engages the Snow from floor 25 on. Regarding the bottom edge of the knife 24 and the upper edge of the swivel element 26 is in the middle the pivot element 26 with a pivot axis 27 Lever arm 28 connected. This is essentially at rest horizontal. It is in one at its rear end Pivot 29 (pivotable in the vertical direction). The pivot point 29 is at the lower end of a support element 30 provided.

A rubber hollow spring 32, on the one hand in a point of attack 31 attached to the lever arm 28 and on the other hand on the support element 30 is supported, holds the lever arm 28 in its essentially horizontal rest position.

At a point of attack 33 (on the back of the swivel element 26) between the upper edge of the swivel element 26 and pivot axis 27 is provided, attacks a cable. This has a rope deflected via a deflection roller 35 34 on that at the top (rope attachment 37) one vertically aligned hollow rubber spring 36 is attached. The hollow rubber spring 36 is in turn z. B. supported on the support beam 4. Likewise the pulley 35. The cable pull mechanism holds the pivoting element 26 elastically in its positive rest position C.

If the knife 24 hits an obstacle, it will Swivel element 26 pivoted into a negative avoidance position D. It is about (in space) Impact point, the pivot axis 27 and the lever arm 28 accordingly (overcoming the spring force of the hollow rubber spring 32) are pushed upwards. Moved at the same time the upper edge of the swivel element 26 with respect to the (lower edge) of the plow top 2 to the front. The Swiveling takes place while overcoming the spring force the hollow spring 36.

As soon as the pivot element 26 is sufficiently strong in the negative Is rotated, it can detach itself from the obstacle and skip this as it were. The two hollow springs 32 and 36 bring it back to rest position C at lightning speed back.

The advantage of the mechanism just described lies in large cushioning resp. Evasion path (see evasion x and crossing height y in Fig. 3). The geometry and the spring elements are largely chosen so that evasion with constant thrust is possible.

About the width of the gap 38 between ploughshare 1 and plow top 2 To be able to adjust as precisely as possible is the lever arm 28 stored in eccentric bushes. By turning the same can the fine-tuning resp. the correction of the manufacturing tolerance be made.

So that the pivot element 26 adapts to the inclination of the floor surface can adjust across the direction of travel are the Bearings of the pivot axis 27 and the pivot point 29 (to the respective Axis of rotation) easily tiltable (e.g. by 1 °). The optimal one Snow removal from uneven floors is also guaranteed that the ploughshare 1 is not a single, itself element extending over the entire plow width, but several individually pivotable, arranged side by side Has elements. Each of these elements can dodge individually and adapt to the slope of the ground.

The invention is of course not limited to the one described Embodiment. Instead of hollow rubber springs e.g. B. coil springs or other elastic elements are used will. In principle, the cable pull mechanism can also can be replaced by a spring-loaded pull rod.

Instead of a hydraulic drive, an electric one be provided. In some circumstances, it can even be beneficial be using a crankshaft mechanism which can be operated by the vehicle by means of a crankshaft is (widespread principle in agricultural machinery).

As already mentioned, the correct guidance of the plate edge can not only with the described advantageous two-lever system, but also with different types of lever and / or Cable mechanisms are accomplished.

In principle, the cushioning system (ploughshare 1) is independent from the top of the plow 2. D. h. if necessary, one or the other part should be different.

In summary, it can be said that the invention created a versatile snow plow has been improved guidance of the snow flow allowed.

Claims (11)

1. Snowplough having a flexible plate (3) which diverts the snow mass and the curvature of which can be adjusted with a mechanism, characterised in that the mechanism (7.1, 7.2, 9, 11, 14, 40) holds the plate (3) at its top edge and its bottom edge in a manner such that it floats in the direction of the x and y co-ordinates situated in its local plate plane, and that the mechanism (7.1, 7.2, 9, 11, 14, 40) always keeps the two edges parallel to one another, with the result that during adjustment the position and direction of the top edge of the plate (3) are always predetermined in such a way that the bending force essentially only operates locally perpendicularly to the plate (30).
2. Snowplough according to claim 1, characterised in that the mechanism includes a dual-lever system (11, 40) in which two levers (11, 40) of different lengths and whose rotational axes (12, 19) are spaced apart from one another predetermine the position and direction of the top edge of the plate (3).
3. Snowplough according to claim 2, characterised in that the mechanism (7.1, 7.2, 9, 11, 14, 40) includes a hydraulic system (7.1, 7.2) which synchronously actuates the two levers (11, 40) of the dual-lever system.
4. Snowplough according to claim 3, characterised in that at least two dual-lever systems are provided which are adapted to be actuated with at least one hydraulic cylinder in each case, and that the various hydraulic cylinders are connected via flow dividers.
5. Snowplough according to any of claims 1 to 4, having a plough blade (1) which scrapes the snow from the ground (25) and which is joined on beneath the plough's upper part (2), characterised in that the plough blade (1) has a plurality of individually hinged elements (26) joined on laterally one alongside the other.
6. Snowplough according to claim 5, characterised in that the elements (26) are mounted in such a way that whenever they hit an obstacle they turn around the impact point and - without being lifted off the ground - assume a negative position (D) in order to then clear the obstacle.
7. Snowplough according to claim 5 or 6, characterised in that the hinged elements (26) are respectively mounted for rotation on a lever (28) which in the rest position (C) is substantially horizontal and is adapted to swivel vertically.
8. Snowplough according to claim 7, characterised in that the element (26) is drawn into a positive rest position (C) by a cable (34, 35, 36) whose point of application is above the joint (27) between the lever (28) and the element (26), and the cable includes a deflection roller (35) and a substantially vertically aligned spring (36).
9. Snowplough according to claim 7 or 8, characterised in that the lever (28) is mounted in eccentric bushes for precisely setting a gap (38) between the element (26) and the plough's upper part (2).
10. Snowplough according to any of claims 5 to 9, characterised in that the elements (26) are adapted to be tilted slightly in the transverse direction, so as to enable them to adapt locally to the slope of the ground.
11. Method for varying the curvature of a flexible plate (3) which diverts the snow mass in the case of a snowplough, the flexible plate (3) being adjustable in its curvature by means of a mechanism, characterised in that the plate (3) is held at its top edge and its bottom edge in a manner such that it floats in the direction of the x and y co-ordinates in its local plate plane and that the two edges are always kept parallel to one another, with the result that during adjustment the position and direction of the top edge of the plate (3) are always predetermined in such a way that the bending force essentially only operates locally perpendicularly to the plate (3).

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