DE2333636C2 - Device for raising and lowering the cutting table of a combine harvester - Google Patents

Description

The invention relates to a device for raising and lowering the cutting table of a combine harvester a horizontal axis by means of a pressure medium-actuated piston-cylinder device connected to a pressure medium source is connected via a valve, which by means of an operating handle., Between two end positions (Raised position and lowered position) and a neutral position in between is adjustable, a stop is provided which limits the lowering movement of the cutting table.

In a known device of this type (DE-OS 21 09 330) the driver must when lowering the cutting table, after he has brought the operating handle into the lowering position, follow the lowering process and after reaching the lowered position of the cutting table the operating handle back into the Bring back normal position. The driver must therefore devote his full attention to the lowering process. In addition, in the known device, the stop limiting the lowering movement of the cutting table is a pressure medium which limits the movement of the piston rod of the piston-cylinder device Piston, the pressure medium line of which is connected to a separate switching valve, which in turn with the pressure medium line leading to the piston-cylinder device and that by means of the operating handle adjustable valve is connected. This design requires a complicated hydraulic Control device, in addition, the adjustment of the stop is cumbersome.

The object of the invention is to design a device of the type mentioned in the introduction in such a way that, with a simple design, convenient adjustment of the stop and lowering of the cutting table are made possible without special attention from the driver. This object is achieved according to the invention in that an electromagnet is arranged in front of the operating handle, which is spring-loaded in the direction of the neutral position of the valve, to hold the handle in the position in which the valve is lowered of the cutting table allows pressure medium to be discharged from the piston-cylinder device, and that the coil of the electromagnet is connected in series with a switch which lies in the path of movement of a stop which is attached to a stubble height indicator connected to the cutting table.
The invention provides a device for lifting and lowering the cutting table of a combine harvester, in which the driver only needs to bring the operating handle into the lowering position to lower the cutting table, after which he can turn his attention to other things. This results from the fact that, after reaching the lowered position of the cutting table, the operating handle spring-loaded in the neutral position automatically returns to the neutral position, which is achieved by the operative connection of the stop limiting the lowering movement of the cutting table and the electromagnet holding the operating handle in the lowering position. The entire control device can be formed with simple and inexpensive mechanical and electrical means, in particular the stop limiting the lowering movement of the cutting table being designed as a simple mechanical stop as a result of its attachment to the cutting table. This stop is preferably connected to the stubble height indicator in an adjustable manner by means of a screw connection.

The invention is explained below with reference to the drawing, for example, the single figure of which is a Figure 3 is a schematic representation in side view of the front part of a combine harvester.

The drawing shows the front part of a combine harvester 1 with a cutting table 2, which by means of a piston is pivotable on a piston rod 4 about an axis 3, the piston in a pressure medium cylinder 5 is, which is rotatably connected to the frame 6 of the combine, while the piston rod is rotatably connected to the cutting table. The combine harvester has a driver's seat 7, and in front of this there is an operating handle 8 for a valve 9, which is through a pipe 10 with a not shown Pressure medium reservoir is in communication. The valve 9 is still through a pipe 11 with the Cylinder 5 connected. In front of the operating handle 8, an electromagnet 12 is arranged, the current through a switch 13 is supplied, and the operating handle 8 must suitably be made of magnetic material be made or provided with a stop piece of such material, so that the electromagnet 12 can hold the operating handle in the position shown with 8 '.

The handle is also connected to a return spring 14. There is a stop height indicator on the cutting table 2 15 arranged with a stop 16 which interact with the switch 13 to open it can, and this stop is on the height indicator 15 adjustable so that it can be screwed up and down.

If it is assumed that the cutting table 2 is in the raised position, it suffices. for closing

ken to pivot the handle 8 into the position shown in the drawing in dashed lines. In this position, the handle of the then energized electromagnet 12 held so that the cutting table 2 s is lowered until the finger or the like of the switch 13 comes into engagement with the stop 16. By then subsequent actuation of the switch 13, the electromagnet 12 is de-energized and the handle 8 is through the spring 14 returned to its neutral position.

The switch 13 can be connected such that it is only affected by the stop 16. In principle, however, a switch can also be provided which is actuated when pivoting the operating handle 8 in the position shown in dashed lines to the To excite electromagnet 12.

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Claims (2)

Patent claims: 1. Device for raising and lowering the cutting table (2) of a combine harvester {') around a horizontal axis by means of a pressure medium-actuated piston-cylinder device (4,5) which is connected to a pressure medium source via a valve (9) which is in the middle an operating handle (8) is adjustable between two end positions (raised position and lowering position) and an intermediate neutral position, a stop being provided which limits the lowering movement of the cutting table, characterized in that in front of the operating handle (8), which is in the direction of the Neutral position of the valve corresponding position is spring-loaded (djrch 14), an electromagnet (12) for holding the handle is arranged in that position in which the valve (9) for lowering the cutting table (1) a pressure medium discharge from the piston-cylinder device (4,5) allowed, and that the coil of the electromagnet is connected in series with a switch (13) which is in the Be trajectory of a stop (16) which is attached to a stubble height indicator (15) connected to the cutting table 2. Apparatus according to claim 1, characterized in that the stop (16) with the stubble height indicator (15) is connected adjustable by means of a screw connection.