A Severing Implement
The present invention relates to a cutting tool specially designed for detaching fodder packed together in round bales. The tool comprises a back-frame designed for securing to a vehicle, for instance to the three-point-linkage of a tractor, a front-frame linked with the back- frame, a support such as a loading fork and a mobile cutting device.
The cutting tool will be used in particular in agriculture with a view to more modern and more environmentally suitable treatment and handling of green fodder such as raw grass, possibly straw, packed together in round bales, Instead of storing this type of fodder in large silos while adding chemicals such as formic acid, it has been found that good results can be achieved by packing together raw grass in tight plastic packages enabling a kind of fermentation without the addition of chemicals. The same method can also be used with straw, but to the latter must be added some chemicals in order to achieve satisfactory .results. When fodder has been packed in such round bales, which may weigh from 150 kg and up to 1 ton, it has been both time- consuming and in part difficult to detach these round bales so that the fodder could be taken to the animals.
From the Norwegian patent 138975 an arrangement is known for detaching fresh fodder, raising it and transporting it to the required point. However, the arrangement is designed for fodder which has been lying in silos or in large accumulations in the open air. The arrangement comprises a cutting unit in the form of a wall structure with cutting edges for pressing into the fresh fodder.
The Norwegian patent 141776 describes a removal device designed for use on a tractor-mounted front loader, for removing packed fodder in like manner as with the above-mentioned arrangement.
GB-2025758A describes a silo-fodder cutter for attachment to a tractor comprising a frame to which the cutting element is secured. This cutting arrangement is used to cut out a block of silo fodder from an accumulation of silo fodder, in which the cutting element is lowered through the mass. Seen from above, the cutting element moves along a rectangular track, cutting out the required block of silo fodder.
As can be seen from the above, the objectives of the previously known technology and the subject matter applied for according to the invention differ to some extent. Whereas the previously known arrangements are used for removing fodder from relatively large accumulations the present cutting tool is used for detaching round bales previously packed together, which appears to be an ever more popular method for treating and storing green fodder. Hitherto it has in fact been customary to detach round bales with the aid of an axe, a tenon saw or tools similar to a motorised saw. This is heavy, labour-intensive and takes a relatively long time.
With the cutting tool according to the invention, the fodder packed together is cut and detached in a quick manner requiring little work. After cutting the round bales are laid out in the manner of a belt and can be transported direct by means of a silo grab or an ordinary hayfork and placed into a fodder conveyor or unloading truck. One may count on a time saving of half an hour per round bale, in addition to the fact that the heavy work is eliminated. It may be possible to remove the packaging material prior to cutting and to use it again, The entire tool can also be used for driving together round bales, and for driving them to the feeding place without damaging the package.
According to the invention this is achieved by means of a cutting tool of the type mentioned initially, which is characterised in that the front-frame is movable in relation to the back-frame in a substantially vertical direction and in that the cutting device is, through a linkage arrangement, connected with the back-frame so that with said relative vertical movement between the frames the cutting device describes an arc, whereas the load on the support exerts the necessary pressure on the cutting device.
The cutting device is advantageously a knife moving to and fro, which is moved with the aid of an eccentric drive and a connecting rod. The eccentric drive may be connected to the power take-off of a vehicle, via an angular transmission and preferably a telescoping cardan shaft. The angular transmission is advantageously in articulated link connection with the front-frame and can be turned about a virtually
horizontal axis with a view to orienting the input shaft of the transmission towards the vehicle's power take-off,
The front-frame is advantageously connected with the back-frame by means of parallel links, preferably located at the top and bottom, respectively, of the frames. The linkage arrangement may consist of a guide rail for the knife, an angled arm, both of these being rotatably linked with the front-frame, and a link rotatably connected to the angled frame and the back-frame, respectively. The front-frame can, in addition, comprise a track for receiving the cutting device when the latter is in the vertical position, Advantageously a locking device should be provided for locking the cutt ing device in the vert ical position,
The cutting device may comprise a hydraulic cylinder for increasing the pressure of the cutting device. Advantageously there may also be a damping device between the guide rail of the knife and a part of the frame so that in case of a possible failure of the locking device the cutting device will not drop instantaneously on to the support.
Other and additional objects, characteristics and advantages will appear from the following specification of a currently preferred embodiment of the invention described by way of illustration without thereby being restrictive, and presented in conjunction with the enclosed drawings, in which
Fig. 1 is a side elevation of the tool according to the invention with the cutting device in the vertical position,
Fig. 2 is a side elevation of the cutting device according to
Fig. 1 with the cutting device partly folded downward, and Fig, 3 is a front elevation of the cutting device according to the invention.
Reference is made to Fig. 1 which shows an embodiment of the cutting tool 1 according to the invention designed for attachment to a vehicle (not shown). Back-frame 3 is attached with the aid of appropriate devices to, for instance, the three-point-linkage of a tractor.
A front-frame 2 is connected with back-frame 3 via parallel links 6 secured at the upper and lower ends, respectively, of frames 2, 3, The parallel links 6 are secured to respective frames 2, 3 with the aid of swivel pins 8. Front-frame 2 is vertically movable in relation to back-frame 3 and will, respectively, move closer to or more further away from back-frame 3 while such a relative vertical motion is in progress. At the lower part of front-frame 2 a support 4 projects, preferably in the shape of a loading fork or pallet fork. A cutting device 5 is, as shown in the figures, designed as a knife arranged for to- und fro-motion in a guide rail 10. A rotating eccentric drive 15 causes, with the aid of a connecting rod 16 between eccentric drive 15 and cutting device 5 said to- and fro-motion. Eccentric drive 15 is secured to an angular transmission 13 with a driving shaft journal 17 which is connected, with the aid of a telescoping cardan shaft (not shown), to power take-off 30 of the vehicle. As a result, the vehicle's power take-off 30 is used to bring about the to- and fromotion of the cutting device. With the aid of link 9, angular transmission 13 is connected in articulated manner with front-frame 2.
The angular transmission 13 can be rotated about a horizontal axis 20. and link 9 is secured at a geometrically correct point to front-trams 2 so that the driving shaft 17 of the transmission always points towards the vehicle's power take-off. This change of direction of shaft journal 17 is intended to avoid large transfer angles of the cardan shaft, which would easily lead to uneven operation owing to compensation between the universal joints of the cardan shaft. An angled arm 12 is firmly connected with guide rail 10, and these parts are again rotatably connected, via a pin 19, with a bracket 18 in turn secured to front frame 2. Angled arm 12 is at its outer end secured to a link 11, by means of a swivel pin 21. Link It is at its other end secured to back-frame 3 by means of yet another swivel pin 22. Guide rail 10, angled arm 12, link 11 end the swivel Dins constitute a linkage arrangement. In addition, the cutting tool comprises a locking device in the shape of a catch 7 capable of locking the cutting device in the vertical position. A spring 23 keeps the catch in position and prevents shaking loose of catch 7.
Fig. 2 shows the cutting device 5 in partly downward-folded position. During use, a round bale is placed on support 4 while cutting device 5 is in the vertical position. As a rule, support 4 is placed on the ground in order thus to facilitate the release of catch 7 by means of e.g. a releasing device 14 such as a line. Cutting device 5 is caused to move to and fro, and by thereafter raising back-frame 3 with the aid of the three-point-linkage, the weight of the round bale will transmit forces through the linkage arrangement, which, owing to its special geometric design, rotates guide rail 10 and thus cutting device 5 about swivel pin 19. As can be seen in Figs, 1 and 2, link 9 between front-frame 2 and angular transmission 13 causes a controlled orientating motion of shaft journal 17 so that the latter always point s in the di rect ion of power take-of f 30, It should however be noted that the distance between power take-off 30 and shaft journal 17 will vary somewhat, and for this reason use is made of a telescoping cardan shaft between these parts. With a conventional tractor the power take-off is about 40 cm above ground level, and angular transmission 13 moves about 15-30 cm up and down, With a view to increasing or reducing this height of movement parallel link 6 can be replaced by longer or shorter links, respectively, and can possibly be of adjustable length. In this manner it is possible better to adapt the cutting tool to different vehicle or tractor types. Cutting device 5 can possibly be equipped with a handle 24 for manually raising it to the vertical position. However, cutting device 15 is normally raised to the vertical position by placing support 4 on the ground and further lowering the three-point-linkage. During use the distance between the ground and support 4 will not be larger than necessary to achieve ground clearance, If this is not necessary, the hydraulic cylinder (not shown) can be located between guide rail 10 and a part of the frame in order to increase the pressure exerted by the cutting device on the round bale. Advantageously a damping device (not shown) can also be provided between guide rail 10 and a part of the frame so as to serve as an additional safety device for the cutting tool, inasmuch as with inadvertent release of locking device 7, cutting device 5 will nevertheless not drop instantaneously on support 4 but carry out a slower and damped downward movement.
Fig. 3 shows the cutting tool seen straight from the front, with an indicated groove 25 for entering or accepting cutting device 5 when the latter is in the vertical position. Front-frame 2 and back-frame 3 are in this figure shown as triangular, but any suitable shape can of course be used. As can also be seen in this Figure, angular transmission 13 is freely supported on angled arm 12 and Its direction is controlled and it is held in position only with the aid of link 9.
In the Figures is shown a cutting device In the shape of a cutting knife, but the invention is not meant to be limited to a cutting knife. It is readily possible to envisage a cutting device in the shape of a rotating blade or a cutting device such as a motorised saw blade.