A CRIMPING ROTOR HAVING PLASTICS FINGERS

Abstract: A rotor for crimping straw material has a plurality of axial rails (11), which each carry a plurality of conveyors in the form of moulded plastics fingers (14) having a certain elasticity. The rails have two oppositely disposed flanges (21 and 23), and each finger is secured in two oppositely disposed openings (27 and 33) in these flanges. A pawl projection (20) on the finger cooperates with a rail part (26) such that the rail part is pressed into an opening in the finger during its introduction into the rail openings and then springs back to its normal position in which it engages said rail part and prevents withdrawal of the finger. Release of the finger with a view to replacement can be effected by imparting such a stroke to the pawl that it is pushed clear of the rail part, and that the entire finger is pushed slightly outwardly, following which it can be removed by hand.

Description: A crimping rotor having plastics fingers Various forms of rotors for crimping straw crops in connection with harvesting are known. In the past, most crimping rotors have been manufactured with steel fingers, frequently Y-shaped, which may be pivotable individually or in groups. A common drawback of crimping rotors having steel fingers is that a rupture of one finger involves a serious risk of damage to the subsequent cutter. Known are also several embodiments of crimping rotors having plastics fingers, which may likewise be stationarily or pivotably mounted. The fingers may e.g. be formed in a plastics plate which is fixedly or resiliently mounted on axial rails in the form of angle irons on the rotor. However, the known plastics fingers have one or more of the following drawbacks : 1) they are relatively expensive, 2) they are difficult to mount, 3) they are not sufficiently sturdy. The invention concerns a crimping rotor of the type defined in the introductory portion of claim 1, and the object of the invention is to provide such a crimping rotor which is not vitiated by the above-mentioned draw¬ backs, and which thus combines an inexpensive and sturdy structure of the plastics fingers and ease of replacement. This object is achieved in that the crimping rotor is constructed as stated in the characterizing portion of claim 1, since this structure enables attachment of the plastics fingers by a single introduction movement which just requires overcoming of the resistance offered by the pawl means during its elastic deformation, just as removal of the finger may be effected solely by a stroke so imparted to the pawl means as will cause it to be pressed downwards, and the finger is simultaneously affected by a force which moves it away from the fixing means and out of the opening in the flange. The fingers may be of a both simple and sturdy structure which may be obtained by an uncomplicated moulding process. The pawl means may be integral with the finger, as stated in claim 2, without this complicating the manufacturing process. A simple embodiment of the fixing means, which also imparts good support to the finger and thus ensures effective attachment of it, is stated in claim 3, and this effect is enhanced by the position of the opening which is stated in claim 4. An additional increase in the face contact area between the finger and the rail may be obtained when the crimping rotor is constructed as stated in claim 5, and this structure involves an improved distribution of the forces by which the rail acts on the finger when the finger is subjected to bending stresses. The rear edge of the bent, plate-shaped flange part may expediently be used for cooperation with the pawl projection of the finger, as stated in claim 6. The invention will be explained more fully below with reference to the drawing, in which fig. 1 in perspective view shows the parts of an embodiment of the crimping rotor of the invention which are necessary to understand the invention, fig. 2 is a vertical section through part of the crimping rotor , fig. 3 is a rear view of a plastics finger, and fig. A is a section along the line IV-IV in fig. 3. In the drawing, the numeral 10 designates one of two or more rings forming part of a crimping rotor. A plurality of axial rails 11, only one is shown in the drawing, is attached to these rings by means of bolts 12 and nuts 13, said rails being evenly distributed circumferentially A plurality of plastics fingers 14 is attached to each rail 11 at regular intervals and in a manner which will be described below. The fingers 14 are moulded of a strong plastics material with a certain elasticity and have the form of a relatively thick plate forming, in the mounted state, a projecting conveying part 15 and an attachment part 16 disposed in the substantially U-shaped rail 11. The conveying part 15 has an outwardly decreasing width, and its outermost portion has an outwardly increasing thickness so that its front side, as seen in the direction of rotation of the rotor indicated by an arrow, will consist of two plane faces which intersect each other at an obtuse angle. The attachment part has an inwardly decreasing width and termi¬ nates in a rectangular fixing part 17. At the root of this fixing part and at both sides thereof, the attachment part is formed with a shoulder 18 projecting slightly in the same direction as the fixing part. The inwardly directed end faces of the finger extend obliquely with respect to the side faces. The attachment part 16 is additionally form¬ ed with a substantially rectangular opening 19 as well as with a pawl projection 20, which extends obliquely outwardly and rearwardly from the innermost and rear edge portion of the opening so that, in its shown unaffected position, it projects somewhat from the rear side of the finger, from which position it may be pressed elastically resiliently into the opening and thus be caused to be essentially flush with the rear side of the finger. The rails 11, to which the fingers are attached, have, as mentioned, a substantially U-shaped cross-section with an inner flange 21 attached to the rings 10, a forwardly directed bottom member 22 forming an obtuse angle with the flange 21, and an outer flange 23 at right angles to the bottom member 22. The inner flange 21 has moreover a bent edge flange 24 which serves to reinforce the profile For each finger, the outer flange accommodates a rectangular opening 25 which adjoins the bottom member 22 and has a size corresponding to the cross-sectional area of the finger at the transition between the conveying part 15 and the attachment part 16. This opening is formed by punching of the plate from which the rail is made, prior to bending. This punching process is performed so that cuts are produced along the bending line between the flange 23 and the bottom member 22 and along the edges of the opening at right angles thereto, and the material member 26 defined by these cut lines is bent so as to be perpen- dicular to the flange 23 and thus parallel with the bottom member 22. The opening 25 serves to receive the wide intermediate part of the plastics finger 14. An opening 27 in the inner flange 21, adjoining the bottom member 22, serves to receive the inner end of the finger, more particularly its fixing part 17. Mounting of a finger 14 on a rail 11 is performed simply by inserting the finger into the outer opening 25 until it is stopped by the pawl projection 20, and a stroke, which causes the pawl projection to yield, then moves the finger further on until the shoulder 17 abuts and is compressed slightly by the inner flange 21 of the rail. This takes place while the pawl projection passes the inner edge of the bent plate member 26 and therefore springs back to its normal position in which, as shown, it engages said edge and effectively prevents withdrawal of the finger. The pawl is kept engaged with the plate edge by the elastic force of the compressed shoulders 18. Removal of a damaged finger is performed by imparting an obliquely outwardly directed stroke to the pawl projection 20 by means of a suitable tool, e.g. a screw driver, such that the pawl projection is forced into the opening 19, and then pushing the entire finger slightly outwardly, following which it can readily be withdrawn completely by hand. The details of both the fingers and the retaining rails may be modified in many ways within the scope of the invention.

Claims: P a t e n t C l a i m s 1. A crimping rotor having plastics fingers carried by axial rails which are distributed along the circumference of the rotor, c h a r a c t e r i z e d in that for each finger each rail has a flange having an opening adapted to receive an intermediate portion of the finger and means spaced somewhat from the flange to fix a rearwardly disposed part of the finger, each finger having an elastically resilient pawl means which cooperates with a part of the rail such that the pawl means permits introduction of the finger into the opening with the rear end first, but prevents withdrawal. 2. A crimping rotor according to claim 1, c h a r a c t e r¬ i z e d in that the fingers consist of a plastics material with a certain elasticity, and that the pawl means is formed by a projection which is so disposed over a depression in the finger that it may be pressed elastically resiliently into the depres ion. 3. A crimping rotor according to claim 1 or 2, c h a r a c t e r i z e d in that each rail further has a second flange which is disposed opposite the first flange and forms a substantially U-shaped profile in combination with said first flange and an intermediate bottom member, and that said fixing means are formed by an opening in the second flange, disposed opposite said first opening, to receive the rear end part of the finger. 4. A crimping rotor according to claim 3, c h a r a c- t e r i z e d in that the fingers are so positioned in the profile flanges at the profile bottom that the fingers engage the bottom member of the profile. 5. A crimping rotor according to claim 4, c h a r a c- t e r i z e d in that the opening in the first flange is formed by a U-shaped cut, and that the plate-shaped part defined by it is bent in an inwardly extending direction about a line, which forms the upper edge of the opening, in a position which is substantially parallel with the bottom member of the profile. 6. A crimping rotor according to claim 5, c h a r a c- t e r i z e d in that the pawl projection on each finger is so disposed that it can cooperate with the rear edge of the bent plate-shaped part of the first flange.

Inventors: LARSEN BOERGE, PEDERSEN PEDER, LARSEN, BOERGE, PEDERSEN, PEDER
Applicants: TAARUP AS MASKINFAB, MASKINFABRIKEN TAARUP A/S
Application year: 1988
Main classification: A01D82
IPC codes: A01D80, A01D82