DEVICE AT A CUTTING UNIT

Device at a cutting unit This invention relates to a device for liquid application in a clearing unit, especially clearing shears, in order to supply growth-inhibiting liquid to the mantle surface of the remaining plant portion simultaneously with clearing of plants.

FI lay-open print 63 158 discloses clearing shears to which a nozzle can be attached which operates simultaneously with the working motion of the device. The nozzle functions as a sprayer for extinguishing agents. However, spraying is only carried out against a part of the circumference of the remaining plant portion, an insufficient effect of the herbicide being obtained. Moreover, this construction results in that a large part of the herbicide goes to waste and that surrounding vegetation is sprayed.

It is the object of this invention to provide a device for liquid application in a clearing unit where the above-mentioned shortcomings are eliminated. This object is achieved in that the invention has been given the characteristic features defined in the claims.

The invention is described more closely in the following with reference to the enclosed drawings which are given as examples without any limiting sense and in which Fig. 1 is a perspective view of a complete device according to the invention, Fig. 2 is a perspective view of the working unit with cutting members in open position, Fig. 3 is a perspective view of an embodiment of mountings for knife and liquid application means with disassembled parts, Fig. 4 is a perspective view of a first embodiment of the flexible liquid application means with disassembled parts, Fig. 5 is a perspective view of a second embodiment of the flexible liquid application means with disassembled parts, and fig. 6 is a partly sectional view on a larger scale of the enclosed part in Fig. 5 shown by dot- and dash lines.

With reference to Fig. 1 the device consists of a driving unit 1, a carrying unit 2 and a working unit 3. The driving unit 1 comprises a frame of preferably light metal carried on one's back by means of straps. The frame serves as a fluid container 4, working fluid being filled at 5 and a filter inserted at 6. An internal combustion engine 7 is attached to the frame and drives via a centrifugal clutch 8 a pump 9 for working fluid. The pump 9 is in fluid connection with the carrying unit 2 by means of fluid hoses 10, 11. A tank for growth-inhibiting liquid 12 is detachably placed at the frame and connected to the carrying and working unit 2 , 3 via a hose 13.

The carrying unit 2 of preferably light metal supports below the working unit 3 and includes at its top carrying and operating handles 14, 15. The operating handle 15 has the double function of serving as a throttle lever for the engine 7 through a wire 16 connected with the engine and to regulate a valve 17 for working fluid arranged within the carrying unit 2 at the operating handle 15. Working fluid is supplied to the working unit 3 via the valve 17 through passages arranged within the carrying unit 2. The hose 13 is arranged along the carrying unit 2, liquid being supplied to the working unit 3 via a shut-off cock 18 with gravity.

The working unit 3, see Figs. 1, 2, comprises a double-acting piston-cylinder device 19 with hoses 20, 21 for fluid supply. The piston rod 22 is adapted to actuate a first cutting member 23 which is movable relative to a second cutting member 24. The cutting members 23, 24 are shown in open position in Fig. 2, a valve 25 for growth-inhibit mg liquid then being closed. The valve 25 is adapted to be opened as soon as the cutting members 23, 24 are changed from open to closed position, whereby liquid can be supplied to the respective means 26, 27 for liquid application. In Fig. 2 only the hose 28 connected with the means 27 is visible.

The cutting members 23, 24 are identical below, and therefore only the cutting member 23 is described in the following. This comprises an upper and a lower knife mounting 29, 30 with a knife 31 placed between these by attaching means. The lower knife mounting 30 and part of the upper one 29 also serve as fitting for the liquid application means 26.

Fig. 3 shows more clearly the arrangement of the mountings 29, 30 with associated knife 31 and liquid application means 26. There are preferably six attaching means for the knife 31, of which two are also intended for attachment of the means 26.

The means for liquid application (Fig. 4) comprises a substantially partially cylindrical member 32 of a material not absorbing liquid, e.g. cellular rubber, having an upper reduced portion 33 (partly cut in the figure) including a groove 34 which is associated with the hose 28. A recess 35 in the member 32 is adapted to receive an elastic means 36 intended for attachment by attaching means of the liquid application means to the lower knife mounting 30, the upper reduced portion getting into contact with the knife 31. Moreover, the liquid application means comprises preferably two similar disc-shaped members 37, 38 of a material not absorbing liquid which each have a number of passing slots 39, the slots of said member 38 being laterally displaced relative to the slots of the member 37 in o rde r t o pr even t t oo gr ea t a l iqu i d f l ow . The s l o t s 39 are in fluid connection with the grove 34 and a disc-shaped member 40 of liquid absorbing material, e.g. foam rubber. A wearing layer 41, e.g. a nylon cloth, is disposed on the member 41. In mounted state the different members included in the liquid application means are preferably combined with each other by glueing. Another embodiment of the liquid application means is shown in Fig. 5, the parts agreeing with Fig. 4 having the same reference numerals. The liquid application means includes a wearing layer 41, a liquid absorbing disc-shaped member 40 and an elastic attaching means 36. The means 36 is placed in a passage through the partially cylindrical liquid absorbing member 42 or a closed recess 43. An upper reduced portion 44 (partly cut in the figure) is provided with a passage 45 for growth-inhibiting liquid which does not pass through and is in fluid connection with the member 40 by means of a slot 46.

When using the clearing shears with engine in operation the operator carries the driving unit 1 on his back and grasps at the same time the handles 14, 15. The throttle lever is in idle position, the valve 17 being in a position for completely open cutting members. When the throttle lever has been turned to half the maximum position the valve 17 is still uninfluenced whereas the motor 7 reaches maximum speed. When the throttle lever is then turned to maximum position the valve 17 is adjusted to such a position that the cutting members 23, 24 are moved towards each other to closed position. During this cutting motion the liquid application means 26, 27 will enclose the mantle surface of the plant portion remaining in the ground. At the same time the two elastic attaching means 36 are stretched resulting in that the slots 39, 46 are extended and liquid can be supplied to the liquid absorbing members 40 and thus moisten the mantle surface. This extension is proportional to the diameter of the plant so that the amount of supplied liquid increases with increasing diameter of the plant. When the throttle lever is again turned to idle position the valve 17 changes its direction of flow, after which the cutting members 23, 24 are brought to open position. The invention is not limited to the illustrative examples indicated above but it is a matter of course that modifications of the application object and also utilization in other cutting units then clearing shears, e.g. a brush saw, are possible within the scope of the inventive idea.