GB2025191A - Device for turning the plough frame of a multiple share plough - Google Patents

Abstract

A device for turning the plough frame about an axis or turning shaft 2 includes two double-acting piston-cylinder units 6, 10 which are pivotably mounted on chassis members of the plough and which act on crank arm 3 and slotted guide 8 of the turning shaft and turn the plough frame in two pressure phases which become effective in succession in opposite directions from one working position through the dead centre position into the other working position. In the second pressure phase the point of application of the piston-cylinder unit 10 on the guide 8 can be shifted in a freely running manner along slot 8' towards the crank arm 3 almost into the dead centre position. Alternatively (Fig. 4, not shown) 8 is replaced by a freely rotating crank 25 and piston and cylinder units 6 and 10 are linked by compression spring 26 to push 10 over the dead centre position. <IMAGE>

Description

SPECIFICATION Device for turning the plough frame of a multiple share plough about an axis or turning shaft The invention relates to a device for turning the ptough frame of a multiple share plough about an axis or turning shaft by means of at least two double-acting piston-cylinder units which are pivotally mounted on chassis members of the plough, and which act indirectly or directly in crank arms of the turning shaft of the plough frame and turn the plough frame in two pressure phases which become effective in succession in opposite directions, from the one working position through the dead centre position into the other working position.

In known multiple share ploughs which are equipped with such a turning device, there is some difficulty in bringing the piston-cylinder units securely through the dead centre position into the other working position. In order to accomplish this, automatically acting reversing appliances for the pressure means have already been provided on the pistoncylinder units, but these are complicated and subject to disturbance.

Furthermore, a requirement has been made that the plough be retained in the half-turned position or in the almost half-turned position, to be brought into the new working position on the preliminary turn of the plough. The advantage of this is that the plough exerts no tilting moment or only a slight tilting moment on the tractor. Stopping of the plough in the half-turned position or in the almost half-turned position necessitates a further control procedure on the part of the operator.

The invention is intended to solve the problem of so constructing a multiple share plough with the device hereinbefore mentioned for turning a plough frame, that the plough frame is brought into the half-turned position and automatically retained by a single control procedure, and that the plough comes into the new working position merely by a second control procedure.

This is achieved by the invention, in that the piston-cylinder units each act on a crank arm of the turning shaft, and that in the second pressure phase the point of application of at least one pistoncylinder unit on the coordinated crank arm can be shifted towards the other crank arm or the other crank arms in a freely-running manner, almost into the dead centre position. In this way, the pistoncylinder unit with the free-runningly shiftable point of application returns almost to the dead centre position after each complete turn of the plough. With a repeated turning procedure, it brings the other piston-cylinder unit or the other piston-cylinder units in a non-positive mannerthrnugh the dead centre position.Furthermore, as a result of the measure of the invention, the piston-cylinder units after the first pressure phase are in a blocking position which corresponds to the almost half-turned position, and the operator can complete the turn art a point which seems appropriate to him.

There are many possibilities of shifting the point of application of a piston-cylinder unit in a free-running manner back into the dead centre position. One advantageous contruction of the device as per the invention consists in that the turning shaft of the plough has an annular groove in which the end of one piston-cylinder unit is free-runningly shiftably led.

In this case, the end of the piston-cylinder unit, when the turn is completed following reversal of the pressure means, is led back until it is almost in the dead centre position, in which it remains ineffective until the commencement of the next turning procedure.

In order to make quite sure that the end of the free-runningly shiftable piston-cylinder unit at the commencement of the turning procedure passes through the dead centre position in the turning direction, the invention provides that the inner defining wall of the annular groove have an inwardly pointed chamfer at each end. Afurther possibility of shifting the point of application of one piston-cylinder unit free-runningly into the dead centre position, consists according to the invention in that one piston-cylinder unit acts on a crank arm which is rotatably mounted on the turning shaft of the plough and that a stop for the crank arm is provided on the turning shaft for each turning direction.

The invention also permits the angle through which the plough frame is turned through the dead centre position and held to be varied, since the maximum length of the free-runningly shiftably led piston-cylinder unit is variable. Afurther solution of the problem according to the Application consists, according to the invention, in that a spring element led to another piston-cylinder unit is connected up on the free-runningly shiftable piston-cylinder unit, which spring element moves the first-mentioned piston-cylinder unit at any given time through the dead centre position in the respective turning direction of the turning shaft, against a stop.In this shaping of the device, the spring ensures that the point of application of the free-runningly shiftable pistoncylinder unit passes through the dead centre position and ensures that the other piston-cylinder unit or the other piston-cylinder units necessarily pass through the dead centre position.

One advantageous construction of the device according to the invention consists in that the inflow pipes of the pressure means are connected together to pressure chambers of the piston-cylinder units, each of which are equally-acting. The control device for the pressure means is simplified in the usual way by this means.

The device according to the invention can be used both in hitched ploughs and also easily detachable mounted ploughs.

The invention is illustrated in the drawing in three exemplified embodiments, Fig. 1, Fig. 2 and Fig. 3 show the rear connecting rod of a three-point hitching device viewed from the The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy. rear, having two piston-cylinder units in three differ ent positions, Fig. 4 show another arrangement of the piston cylinder units, Fig. 5 show another exemplified embodiment with an easily detachable mounted plough in top plan view, Fig. 6 shows another position for Fig. 5.

In the exemplified embodiments as per Figures 1, 2 and 3, the rear connecting rod is marked with 1, on which the turning shaft 2 of the unillustrated plough frame is rotatably mounted on a fixed axis 1a of the rear connecting rod 1. Connected to the turning shaft 2 is a crank arm 3, on which at point 4 acts the piston rod 5 which is slidingly led in the cylinder 6. The cylinder 6 is pivotably mounted in the rear connecting rod 1 at point7.

A slotted guide 8 with the slot 8' is firmly connected to the turning shaft 2. In the slot 8' is slidingly led the end of the piston rod 9 of the cylinder 10, which is pivotably mounted at the point 11 on the rear connecting rod 1. The hydraulic or pneumatic pressure means is fed to the cylinders 6 or 10, at the one end of the cylinder through the pipes 12 or 13, and at the other end of the cylinder through the pipes 14Or 15. The pipes 12 and 13 or 14and 15are led together to one pipe 16 or 17, which are after nately actuated with the pressure means at 18 or 19 by a common unillustrated control valve. A limit stop 20 or 21 is provided for the crank arm 3 on the rear connecting rod 1, for each turning direction.

During working, the crank arm 3 in the position as per Fig. 1 rests against the stop 20, and the pistoncylinder unit9 and 10 is in the position indicated in dotted lines, i.e. in the dead centre position. If pressure means is brought into the cylinders 6 or 10 by means of the control valve at 18 indicated by the plus sign, which circumstances are shown by shading, the point of application 4 of the piston rod 5 on the crank arm 3 begins to move in the direction of the arrow. Simultaneously, the end of the piston rod 9 of the cylinder 10 presses against the inner defining wail of the slot 8'.By the rotating movement of the crank arm 3 and the inner defining wall of the annular groove 8 connected thereto, the piston-cylinder unit 9 and 10 is brought by friction closure through the dead centre position in the turning direction, after which the hydraulic pressure becomes effective and the end of the piston rod 9 is pressed against the final limit of the slot 8'. Whilst at the of the turning movement the torque of the pistoncylinder unit 9 and 10 is very small, the torque of the piston-cylinder unit 5 and 6 is at its maximum. The further the turning movement has progressed, the smaller becomes the torque exerted on the crank arm 3, and it is equal to zero when the crank arm 3 has come into the dead centre position illustrated in Fig. 2.The torque exerted by the piston-cylinder unit 9 and 10 is greater the further the turning procedure has progressed. The torque of the piston-cylinder unit 9 and 10 in the position shown in Fig. 2 is sufficient to bring the piston-cylinder unit 5 and 6 through dead centre. The two piston-cylinder units are then in the position as per Fig. 3, in which the piston-cylinder unit 9 and 70 is in the final position, whereas the torque of the piston-cylinder unit 5 and 6 is already so large that the turning movement can be completed. This, however, is oniy possible if the second pressure phase is initiated via the control valve at 19 indicated by a plus sign.Before this is initiated by the operator, the turning movement is blocked in the position as per Fig. so that the trac tor driver can carry out the driving movements which are necessary on the preliminary turn. When these are terminated, the turning procedure is comp leted by reversing the pressure means current until the crank arms 3 rests against the stop 21. It should also be mentioned that in order to assist the movement of the piston-cylinder unit 9 and 10 from the dead centre position into the position as per Fig. 1 which is shown in inked-in lines, the inner defining wall of the annular groove 8 has an inwardly pointed chamfer 8" at each end.

In the exemplified embodiment as per Fig. 4, the reference numbers used in Figures 1 to 3 are used for similar parts. Differing from the exemplified embodiment already described, a stop member 22 is connected to the turning shaft 2 carrying the crank arm 3, which stop member has two stops 23 and 24 facing each other. Furthermore, on the turning shaft 2 there is freely rotatably seated a crank arm 25, on which the piston rod 9 of the piston-cylinder unit 9 and 10 acts flexibly. The drawing shows the device in its working position. Here, the piston-cylinder unit 9 and 10 is in the dead centre position or almost in the dead centre position. Between the two cylinders 6 and 10 there is connected up a compression spring 26 which endeavours to bring the piston-cylinder unit 9 and 10 into the position indicated by dotted lines, in abutment against the stop 23.In order to initiate the turning procedure, the control valve is actuated with the pressure means at 18, whereby the piston-cylinder unit 5 and 6 acts with decreasing torque, and the piston-cylinder unit 9 and 10 acts with increasing torque on the turning shaft 2. If the crank arm 3 has come into the dead centre position, the torque exerted by the piston-cylinder unit 9 and 10 ensures that the crankarm 3 is brought through the dead centre position.

Figs. and 6 show the use of the invention on an easily detachable mounted turn wrest plough, such as is described, for example, in German Patent 1 211 012, according to which, when the working direction is changed, the plough frame 2a is brought in hori zontal direction out of the position illustrated in inked-in lines into the position illustrated in dotted lines, and heraturns through approximately 1 80" about a bearing axis 27 which is supported by an unillustrated supportwheel. This turning is produced by the rear connecting rod 1b being provided with a perpendicular pin 28, on which an intermediate part 29 is horizontally pivotably mounted, whose free end is formed into a bevel wheel 30 which is in engagement with a bevel wheel 31, which is connected to the end of the plough frame 2a rotatably mounted on the bearing axis 27.

The latter has a crank arm 32, on which the one piston-cylinder unit 5 and 6, which is universally movably mounted on the rear connecting rod 1 b, acts. The other piston-cylinder unit 9 and 10 is mounted on the intermediate part 29 and engages with its piston rod 9 in an annular groove 8', whose defining walls 8 are connected to the bearing axis 27.

If, in order to change the working direction, the two piston-cylinder units 5 and 6 and 9 and 10 are actuated with the pressure means, the piston rod 5 of the piston-cylinder unit 5 and 6 which is moving out covers the angle which the intermediate part 29 forms with the plough frame 2a and the bearing axis 27, whereby, at the same time, the bevel wheel 30 connected to the intermediate part 29 necessarily turns the plough frame 2a via the bevel wheel 31 which is connected to the plough frame 2a.Here, if the two fulcrum points of the intermediate part 29 and the point of application 33 of the piston rod 5 lie in a straight line, i.e. are in the dead centre position, the end of the piston rod 9 rests against the end of the annular groove 8' and forms a lever arm, so that the force acting on the piston rod 9 brings the parts 29 and 27 through the dead centre position into the position as per Fig. 6.

After the reversal of the pressure means, the end of the piston rod 9 moves in a freely-running manner back in the annular groove 8' and the piston-cylinder unit 5 and 6 becomes effective with an extending lever arm, whereby the intermediate part 29 and also the plough frame 2a are forced into the position illustrated in dotted lines, with which the turning movement is terminated.

The turning device is intended for a multiple share plough. It is essentially composed of two doubleacting piston-cylinder units, which are pivotably mounted on chassis members of the plough and act indirectly or directly on crank arms of the axis or turning shaft of the plough frame. The plough frame is turned about the turning shaft in two pressure phases becoming effective in succession in opposite directions, from one working position through the dead centre position into the other working position.

With the aid of the invention, the plough frame is intended to be able to be stopped in the half-turned position, i.e. in the dead centre position of the one piston-cylinder unit at the end of the first pressure phase. This is made possible by the fact that the point of application of at least one piston-cylinder unit on the crank arm coordinated therewith, via which it acts upon the turning shaft, can be shifted in a freely running manner almost into its dead centre position, towards the other crank arm or the other crank arms.

In the first pressure phase, the piston-cylinder unit with the point of application which is shiftable in a freely running manner in the second pressure phase, brings the other piston-cylinder units in a forceclosed way through the dead centre position. The first pressure phase is automatically terminated shortly after the dead centre position is exceeded. In the second pressure phase, which has to be controlled separately, the piston-cylinder units turn the plough frame into the new working position, in which the piston-cylinder unit swivels back into its dead centre position with the free runningly located point of application.

Claims (9)

1. A device for turning the plough frame of a multiple share plough about an axis or turning shaft by means of at least two double-acting piston-cylinder units which are pivotably mounted on chassis members of the plough, and which act indirectly or directly on crank arms of the turning shaft of the plough frame and turn the plough frame in two pressure phases which become effective in succession in opposite directions, from the one working position through the dead centre position into the other working position, the piston-cylinder units each acting on one crank arm of the turning shaft, and in the second pressure phase the point of application of at least one piston-cylinder unit on the coordinated crank arm can be shifted in a freely running manner towards the other crank arm or the other crank arms, almost into the dead centre position.

2. A device as claimed in claim 1, in which the turning shaft of the plough has an annular groove in which the end of one piston-cylinder unit can be shifted in a freely running manner.

3. A device as claimed in claim 2, in which the inner defining wall of the annular groove has an inwardly pointed chamber at each end.

4. A device as claimed in claim 1, in which one piston-cylinder unit acts upon a crank arm which is rotatably mounted on the turning shaft of the plough, and a stop for the crank arm is provided on the turning shaft for each turning direction.

5. A device as claimed in any of claims 1 to 4, in which the maximum length of the free-running shiftably led piston-cylinder unit is variable.

6. A device as claimed in any of claims 1,2,4 or 5, in which a spring element is connected on the free-running shiftable piston-cylinder unit the element being led to another piston-cylinder unit which moves the piston-cylinder unit at any given time through the dead centre position against a stop in the respective turning direction of the turning shaft.

7. A device as claimed in any of claims 1,2,3, or 5 for a turn wrest plough, in which the plough frame which is mounted on a bearing axis supported at the free end by means of a supporting wheel has a bevel wheel segment which meshes with a bevel wheel segment which is located at the end of an intermediate part pivotably mounted about a perpendicularly standing pin of the rear connecting rod, one pistoncylinder unit being universally movable mounted on the rear connecting rod and acting upon a crank arm of the plough frame, the free-running piston-cylinder unit being pivotably mounted on an intermediate part and the piston rod being free-running shiftably led in an annular groove, which is connected to the end of a bearing axis.

8. A device as claimed in any preceding claim, in which inflow conduits for the pressure medium are connected together in each case to equally-acting pressure chambers of the piston-cylinder units.

9. A device for turning the plough frame of a multiple share plough about an axis or turning shaft substantially as hereinbefore described with reference to and as shown in the drawings.