MARTIKAINEN, Unto (Kihmulankatu 58, Iisalmi, FI-74130, FI)
Claims
1. A release mechanism, characterized in that it comprises:
- levers (5, 7) coupled in series by means of joints (9, 10), through which levers a force is transferred to a returning spring member (3), when said levers are moved by the force, and
- a blade structure (6) coupled by means of a joint (12), a force effective on the blade structure being transferred to the levers (5, 7), when an impact force effective on the blade structure (6) moves the blade structure (6) and the levers (5, 7) coupled to the same.
2. The release mechanism according to claim 1 , characterized in that the levers (5, 7) are connected by means of a movable joint (10).
3. The release mechanism according to claim 1 or 2, characterized in that the force caused by an impact with an obstacle is transferred by the levers (5, 7) to the returning spring member (3).,
4. The release mechanism according to any of the claims 1 to 3, characterized in that the spring member (3) is arranged to return the blade structure (6) to the normal position after the impact.
5. The release mechanism according to any of the claims 1 to 4, characterized in that the force required for releasing the blade structure (6) is adjustable.
6. The release mechanism according to any of the claims 1 to 5, characterized in that the position of the levers (5, 7) is adjustable to adjust the force required for releasing the blade structure (6).
7. The release mechanism according to any of the claims 1 to 6, characterized in that the force returning the spring member (3) is adjustable.
8. The release mechanism according to any of the claims 1 to 7, characterized in that it is fitted in an apparatus comprising a frame structure
(1 , 2, 4), to which the levers (5, 7) and the blade structure (6) are coupled by means of joints (11 , 12).
9. The release mechanism according to any of the claims 1 to 8, characterized in that the spring member (3) is a spring.
10. The release mechanism according to any of the claims 1 to 9, characterized in that it is fitted in a plough.
11. The release mechanism according to claim 2, characterized in that the spring member (3) is connected to said movable joint (10).
12. The release mechanism according to claim 2, characterized in that the spring member (3) is connected to one of the levers (5, 7).
13. The release mechanism according to claim 2, characterized in that the spring member (3) is connected to an extension (5a) of the lever.
14. The release mechanism according to. claim 11 or 12, characterized in that the movable joint (10) is placed higher in relation to the ground than a straight line (8) extending via the joints (9; 11) at the ends of the levers (5, 7). ■
15. The release mechanism according to claim 13, characterized in that the movable joint (10) is placed lower in relation to the ground than a straight line (8) extending via the joints (9, 11) at the ends of the levers (5, 7).
16. The release mechanism according to claim 14 or 15, characterized in that the distance between the movable joint (10) and said straight line (8) is adjustable.
17. The release mechanism according to claim 1 , 11 or 12, characterized in that one of the levers (5) is coupled by means of the joint (11) to a rigid lever
(4) having a curved shape, inside which one of the joints (10) in said lever (5) can be received.
18. The release mechanism according to any of the claims 1 to 17, characterized in that one of the levers (5) is coupled by means of the joint
(11) to the rigid lever (4), wherein said joint (11 ) is higher than the joint (10) between said joints (5, 7), and the joint (9) between the second joint (7) and the blade structure (6).
19. The release mechanism according to any of the claims 1 to 18, characterized in that as the levers (5, 7) are moved by the impact force, the moment arm produced by the effective force is changed so that a greater and greater portion of the effective force is effective on the spring member (3).
20. The release mechanism according to any of the claims 1 to 19, characterized in that the moment arm of the effective force in relation to the joint (10) between the levers (5, 7) is increased in the impact. |
RELEASE MECHANISM
The present invention relates to a release mechanism.
The release mechanism is intended for turning the blade of a wing intended for the ploughing of solid material.
In known release mechanisms, the turning of the blade is based on a single rigid joint and a single axial joint in a blade holder. This principle is used in ploughs, in which the angle between the blade and the ground is about 90°.
In a structure where the blade angle deviates from this, it is not possible to release the blade. When a conical wing is used, i.e. the known wing shape, the angle of the blade against the ground deviates from 90°. When applying a conical wing and a blade angle of less than 90°, the plought becomes throwing, wherein the blade is tilted backwards.
The blades are fixed to a blade holder with a swing for the case of impacts. The release mechanism refers to the return of the blades of the plough to the initial position after an impact. The blade must "yield" when the plough hits, for example, well covers and curbs. The return to the initial position may be effected e.g. by means of a spring member. The release method is a safety factor affecting the user and the working environment. Above all, it affects the ease of use and the serviceable life of the basic machine. Without the releasing of the blades, the structure of the basic machine is subjected to excessive loading. The plough does not prod during driving, and the release method enables driving at higher speeds.
The aim of the invention is to articulate the blade so that the blade of a plough equipped with a blade angle smaller than 90° can be released when it hits an obstacle. The returning is effected by a spring member.
The releasing force of the blade can be adjusted by changing the linear deviation of the pivots or by changing the thrust of the spring member. Particularly the mutual position of the pivots affects the force required for turning the blade. On one hand, the blade must not move and yield during normal ploughing, but on the other hand, the blade must move when it is
subjected to a sufficiently great force. A corresponding function cannot be achieved by adjusting the spring member if it is, for example, a coil spring that is compressed or stretched by a force.
The blade can be articulated by means of two separate levers which move the spring member and are moved when the blade holder moves. The levers are articulated to each other by movable joints. The lowermost of the levers is articulated to the blade holder, and the uppermost lever is articulated to a frame structure, such as the wing, the wing support or another support structure integrated in the frame structure. In a first example, the spring member is articulated between the lowermost and the uppermost levers, and it moves with the levers upwards, away from the surface to be ploughed. Preferably, the joints of the spring member and the levers and their rotation axes are joined at and mounted to the lower end of the spring member. The upper end of the spring member is movably supported to the frame structure, for example the wing support, in a suitable way. In another example, the spring member is articulated to the uppermost lever so that when the levers move downwards, the spring member is compressed upwards. The spring member is fixed to such a part of the uppermost lever which has a movement upwards.
The thrust/release force of the spring member can be altered. When the spring member is a compressible spring, its rigidity can be altered by pretensioning of the spring, that is, by changing the length of the spring. In particular, the rigidity can be altered by changing the angle between the levers. The greater the angle, the greater the force initially required for turning the levers and moving the spring member, i.e., for releasing the mechanism. The adjustment is made, for example, by moving the spring member higher or lower, wherein the position of the related joint is also changed.
More precisely, the release mechanism according to the invention is characterized in what will be presented in claim 1. More detailed embodiments will be presented in the other claims.
In the following, the invention will be described in more detail by means of examples and with reference to the appended drawings, in which
Figs. 1 a and 1b show a first example of the invention in a reduced principle,
Figs. 2a and 2b show a second example of the invention in a reduced principle,
Fig. 3 illustrates the application of the invention in a plough,
Fig. 4 shows an embodiment of the first example of the invention, and
Fig. 5 shows an embodiment of the second example of the invention.
In the appended drawings, the same reference numerals refer to the same parts of the apparatus.
As shown in Figs. 4 and 5, the frame 1 of the apparatus constitutes, for example, a concave wing, which in this case constitutes a side-throwing wing. The radius of curvature of the wing is smaller at one end and greater at the other end of the wing. Figures 1a and 2a show the same structures in a reduced manner.
The frame 1 is supported from the back by frame structures or a support profile 2, to which a number of other parts are coupled as needed, for example the means for coupling the apparatus to a working machine. The support profile 2 simultaneously supports a spring member 3 which is connected to the frame 1 , for example by means of the support profile 2. The spring member 3 is vertical or slightly slanted, also in relation to the line 8. An arm 4, which in this case is horizontal and extends backwards, is rigidly mounted to the frame structure, the frame 1 and/or the support profile 2, for example the lower surface of the support profile 2. The shape of the arm 4 may vary as needed. The arm 4 has, for example, a curved shape as shown in Fig. 4, to receive the joint 10, wherein the structure can be made lower and the levers shorter. A first lever 5 is coupled to the arm 4 by a joint 11 , to rotate around a horizontal axis by means of the joint 11. The joint 1 1 is at a distance from a joint 12 in the frame 1. A joint 10 is placed between the joints 1 1 and 12. The joint 12 is used to mount a blade holder 6 and a blade fixed in it to the frame 1. The blade and the blade holder are also jointly called the
blade structure, whose more detailed structure may vary. The blade holder 6 can rotate by means of the joint 12 around a horizontal axis of rotation. By these means, the blade holder 6 can be returned to the normal position. A second lever 7 is coupled to the blade holder 6 by a joint 9, to rotate around a horizontal axis by means of the joint 9.
The levers 5 and 7 in series are coupled to each other by the joint 10, to which the spring member 3 is also coupled in the example of Fig. 4. By means of the joint 10, the different parts can rotate around a horizontal axis of rotation. The lever 7 is coupled to the frame 1 by means of the blade holder 6 and the lever 5. The mutual position between the levers and the joints, as well as their numbers may vary, depending on the design. In Fig. 4, the angle between the levers 5 and 7 on the side of the spring member 3 is slightly greater than 180°, for example 182° to 184°. In the embodiment of Fig. 1 a, the joint 10 is placed higher than the straight line extending via the joints 9 and 11 , so that the force of the obstacle effective on the blade holder 6 and on. the arm 7 pushes the joint 10 upwards controlled by the lever 5, that is, it releases the blade. The joint 10 is displaced off the ground or the surface to be ploughed when the plough is in the. operating position. The joint 11 is higher than the joint 9 and, for example, at the same level as the joint 12. The joint 12 is typically between the joints 9 and 10, seen in the horizontal direction. If the spring member 3 is a coil spring, it is compressed. The coil spring is typically equipped with a guide, around which the coil spring is placed and which is connected to both the joint 10 and the support profile 2. The coil spring returns the blade holder 6 to its initial position.
In the embodiment shown in Fig. 2a, the joint 10 is placed lower than the straight line extending via the joints 9 and 11 , so that the joint moves downwards. However, the lever 5 comprises an extension 5a extending past the joint 11 and turning upwards and compressing the spring member 3 connected to the extension by means of a joint 13. The joint 11 is between the joints 10 and 13, seen in the horizontal direction. Thus, the spring member 3 can be placed upright behind the frame 1.
The spring member can also be a spring that is extended as a result of an impact, in which case it is coupled to such a point in a lever or a joint that causes extension of the spring when moved. Typically, it is a coil spring that
is commonly available and has a simple design. The spring member can also be a cylinder and an accumulator coupled to it, which receives and stores the medium coming from the cylinder and returns it to the cylinder to restore the position of the blade. The cylinder and the accumulator make up a more complex system.
The force required for releasing the blade can be adjusted by deviating the position of the joint 10 between the levers 5 and 7 in relation to the line 8, that is, by adjusting the distance of the joint 10 from the line 8. In the example of Fig. 1a, the spring member 3 can be mounted solely to the lever 5 or the lever 7 by a joint.
The normal position refers to the position of the blade during ploughing (for example, tilted backwards at an angle of 60°).
Figure 3 shows a plough in which the invention is applied. The parts and levers of several release mechanisms are normally arranged pairwise next to each other, and a desired number of them is provided for each blade, for example two pairs, to achieve sufficient control. Two or more levers of the same blade (lever 5 or lever 7) are connected to each other by a beam, to increase the rigidity.
In conventional systems, the resisting force of the spring member increases continuously as the blade is turned, which loads the structures significantly even after an impact with an obstacle. If the blade is not to move all the time, for example the spring must be sufficiently tense, which, in turn, causes increasing loads on the structure as the blade turns and affects the spring member. If the maximum allowed load of the structure is 1.5 F, the spring member must be selected so that the blade starts to turn already at a force of 0.5 F 1 depending, for example, on the spring constant.
The presented examples and lever systems, in turn, provide that the force in the force/time coordinate system has a clear short maximum peak at the beginning when the blade starts to turn, and after the releasing, the required force is considerably reduced and facilitates the turning of the blade, and the structures are not subjected to further loading. Thus, the loading caused by the obstacle can be 1.5 F at the moment of releasing, because after that, the
loading is reduced, for example to the level of 0.5 F. The operation is based on a changing moment arm when the lever system is turned, wherein a greater and greater proportion of the force is also subjected to the spring member and not almost solely from one lever to another. The moment arm increases when the angle between the levers increases. The blade does not move unnecessarily during the operation, because the force required for the releasing is sufficiently great.
As shown in Figs. 1 b and 2b, when the blade hits an obstacle 14, the blade holder 6 turns backwards. By means of the joints 9, 10 and 11 , the force effective on the blade can be directed to the spring member 3, wherein the spring member 3 is tensioned. After the obstacle 14 has passed, the spring member 3 returns the blade holder 6 back to the normal position shown in
Figs. 1a and 2a. Most expediently, the energy stored in the spring member 3 is used for returning the position.
Within the scope of the invention, also arrangements different from the above-described situation are feasible; consequently, the apparatus to be used may be another apparatus in which a blade must avoid obstacles, such as a snow-plough or an apparatus intended for the ploughing of solid material, fixed in a ploughing automobile.