A TEDDER

Abstract: A tedder has a main frame (10) adapted for suspension from the three-point suspension of a tractor, a carrier beam (11) for a plurality of rake rotors (21) being pivotally suspended from said main frame in a manner such that the angle of the rotor axes with the vertical can be changed by rotation of a screw spindle (17) from the cab of the tractor, said screw spindle being engaged with a nut (16) on a bracket (15) on the beam. A height adjustment mechanism is activated by an angle lever (54, 67) which is pivotally arranged in the beam, or a member firmly connected therewith, one arm (67) of said angle lever being so connected with the stationary end of the screw spindle (17) that said spindle rotates when the inclination of the rotor shafts is changed.

Description: A tedder The invention concerns a tedder of the type defined in the introductory portion of claim 1. In such a tedder the angle adjustment mechanism for pivoting the carrier beam makes it possible to change the inclination of the rake rotors with respect to the travelling direction to obtain optimum spreading of the mown grass crop. Height adjust¬ ment means for the travelling wheels make it possible to change the inclination of the rake rotors such that the desired height of the rake springs above the ground is maintained constantly in the direction of forward travel. In the known tedders of the present type the angle adjust- ment and the height adjustment are effected independently of each other, e.g. by means of hydraulic cylinders as shown and described in DE-B2-26 13 027, or by means of screw spindles and cord drives as shown and described e.g. in DE-C2-25 45 712. The object of the invention is to provide a tedder of the present type which is so adapted that adjustment of the angle of the rake rotors is automatically accompanied by a corresponding height adjustment of the travelling wheels. This object is achieved in that the tedder is constructed as stated in the characterizing portion of claim 1, since in this structure the axis of rotation of the angular lever is displaced when the carrier beam is pivoted to change the angle, and is rotated because of the connection of one arm with a point fixed with respect to the main frame such that the height adjustment means is displaced to change the wheel height. This adjustment can be per¬ formed from the cab of the tractor in the operation of the tedder. The embodiment of the tedder defined in claim 4 entails that the height of the wheels can be adjusted indepen¬ dently of the angular position. Other expedient details in the tedder of the invention are defined in claims 5-9. Claim 10 defines an embodiment of the tedder in which the rake rotors are driven by a shaft extending through the carrier beam, while claim 11 defines an embodiment in which the drive shaft in the carrier beam is divided into sections between the rotor shafts. The invention will be explained more fully below with reference to the drawing, in which fig. 1 is a vertical, partially sectional view of an em¬ bodiment of the tedder of the invention with a divided drive shaft r fig. 2 is a corresponding vertical view of a second embo¬ diment having a through-going drive shaft, and fig. 3 is a vertical section through an amended embodiment of a part of the tedder. In fig. 1, 10 is a part of a main frame which is adapted to be suspended from the three-point suspension of a trac¬ tor in a generally known, not shown manner. A hollow carrier beam 11, which has a substantially rectangular cross-section and extends perpendicularly to the travel¬ ling direction in the entire length of the tedder, is pivotally suspended from the main frame 10 by means of arms 12, which are rotatable about a shaft 13 extending between nose members 14 on the main frame. An upwardly extending, angular bracket 15 is secured on the upper side of the carrier beam 11, and a nut 16 is rotatably arranged at the outer end of the bracket. A screw spindle 17, which can be rotated from the cab of the tractor in a manner not shown, extends smoothly through a sleeve 18 which is ro- tatably mounted in an upstanding bracket 19 secured to the main frame 10. A lock disc 20 is secured on both sides of the sleeve 18 on the screw spindle 17, preventing axial displacement of the screw spindle which extends threadedly through the nut 16. The advantage of the mechanism des- cribed above is that the carrier beam 11 can pivot about the shaft 13 by rotation of the screw spindle 17. A plurality of rake rotors, only one of which is shown in the drawing, are rotatably suspended from the carrier beam. The rake rotor, which is generally designated by 21, has a hub disc 22 mounting, e.g. by means of screws or rivets 23, a plurality of arms 24 which carry rake means 25. The hub disc 22 is secured on a hollow shaft 26 which is rotatably mounted by means of ball bearings 27 and 28 on another hollow shaft 29, whose uppermost part located inside the carrier beam 11 is rotatably, but axially im¬ movably arranged on the lower, pin-shaped end of a carrier block 30, which is in the form of a body of revolution and whose upper part forms a flange which is secured to the top wall of the beam. Also the upper end of the hollow shaft 26 extends through an opening in the beam bottom, and this end part mounts a crown wheel 31 which is located inside the beam and which is engaged with a bevel pinion (not shown) on drive shaft sections (not shown) extending in the longitudinal direction of the beam to their respec¬ tive adjacent rotors. One of the drive shaft sections is drivingly connected with the power take-off of the tractor through a transmission mechanism (not shown) so that the rake rotors can be driven from this. The lower end of the inner hollow shaft 29 mounts an arm 32 on whose outer end a wheel fork 33, which carries an air rubber wheel 34, is pivotally secured. The wheel fork 33 is connected through a link 35 with the lower end of a rod 36, which extends through and is slidable in the hollow shaft 29 and a central bore in the carrier block 30 as well as a sleeve 37 rotatably mounted in a cylindrical recess in the upper side of the block. The upper end of the rod 36 positioned above the carrier beam 11 is con- nected through a link 38 with one arm 39 of an angle lever, which is pivotally mounted on the bracket 15 at a pivot 40, and whose other arm 41 is provided with a slot 42 which rotatably and slidably receives a pin 43 which is rotatably mounted on the end of the screw spindle 17. When the inclination of the rake rotors is changed by ro¬ tating the screw spindle 17, e.g. in a direction such that the nut 16 is moved outwardly on the spindle, the carrier beam 11 pivots about the shaft 13 so that the angle of the rotor axes with the vertical is reduced. Since the pivot 40 of the angle lever participates in the pivotal movement of the beam, while the pin 43 connected with the angle lever 41 is stationary, the angle lever is simultaneously rotated clockwise, thereby lifting the rod 36 and the wheel 34. This compensates for the increase in the minimum distance a of the rake means 25 from the ground, which is caused by the change in the angle of the rotor axes with the vertical. The rotatable sleeve 37 mounts a disc 44 which is posi¬ tioned on the carrier block 30 and which is firmly con¬ nected with the upper end of the hollow shaft 29 through a bolt 45 which is parallel with the rotor axis and extends through a curved slot in the carrier block 30, the carrier arm 32 of the travelling wheel 34 being mounted on the hollow shaft 29. One end of a Z-shaped control arm 46, which extends through an opening in the beam wall, is welded on the upper side of the rotatable disc 44, and the other end of the control arm 46 is rotatably connected with a control rod 47 extending along the beam. Axial movement of this control rod thus causes the disc 44 to rotate and thereby the hollow shaft 29 carrying the wheel, which is thus steerable. In fig. 2 the parts corresponding to those in fig. 1 are designated by the same reference numerals as in fig. 1. In the embodiment shown in fig. 2 the hub disc 22 is se¬ cured on a round member 48 which is slidable, but fixed against rotation on a hollow rotor shaft 49, which is in turn rotatably, but axially immovably mounted on a center shaft 50, whose upper end mounts the crown wheel 31 posi¬ tioned in the bottom of the carrier beam 11. The upper end of the center shaft 50 extending through the crown wheel mounts a disc 51, which is firmly connected with the ro- tatable disc 44 upwardly in the carrier beam and thereby with the control mechanism 46, 47 through the bolt posi¬ tioned in the vicinity of the periphery. A drive shaft 52, which is driven by the tractor in a known manner (not shown), here extends uninterruptedly through the carrier beam 11 and carries a bevel pinion (not shown) adjacent each crown wheel, said bevel pinion being engaged with the crown wheel in question to drive the hollow shaft 49 and the rake rotor 21 through the round member 48. A control shaft 53, which extends in parallel with the drive shaft 52, is rotatably journalled in the carrier beam 11, said control shaft carrying at each rotor shaft an arm 54, which emerges through an opening in the rear wall of the beam and is thus connected with a preferably hexagonal rod 55, which is parallel with the rotor axis and is axially slidably controlled in control projections 56 on the beam, such that this rod is displaced in paral¬ lel with the rotor axis when the control shaft 53 rotates. An inwardly extending angle arm 57 on the lower end of the rod 55 carries a rotatable roller 58 on its inner end, said roller being positioned between a flange 59 on the round member 48 and the upper side of the rotor hub disc. Another roller 60 is located between two radial shoulder surfaces on the round member 48 below the rotor hub disc 22 and is rotatably mounted on an angle arm on the upper end of another preferably hexagonal rod 61, which is pa¬ rallel with the rotor axis and is axially slidably guided in a cross-sectionally U-shaped guide fitting 62 on an arm 63, which is secured to and extends forwardly from the lower end of the center shaft 50. This arm 63 pivotally mounts a wheel fork 64, which carries the air rubber wheel 34 and has an angle arm 65 so connected with the rod 61 through a link 66 that the wheel fork pivots when the rod is displaced. An additional arm 67 is secured on the guide shaft 53 opposite the screw spindle 17, said arm 67 defining to¬ gether with the arms 54 an angle lever and extending down through an opening in the bottom of the carrier beam. The outer end of this arm is rotatably connected with the lower end of a double-curved articulated rod 68, which extends externally of the drive shaft 52 up through an opening in the top wall of the beam, and whose upper end is rotatably connected with the stationary end of the screw spindle 17. If the screw spindle is rotated e.g. in such a direction that the nut 16 moves outwardly on the spindle, the car- rier beam 11 pivots about the shaft 13 so that the angle of the rotor axes with the vertical is reduced. Also the distance between the nut 16 and the upper end of the arti¬ culated rod 68 is reduced, causing the lower end of said rod to exert a pull in the arm 67 and to rotate the con¬ trol shaft 53 counterclockwise. The arms 54 then press the rods 55 downwards, and this movement is transferred through the rollers 58, the rotor hub discs 22, the round members 26 and the rollers 60 to the rods 61, which there¬ by pivot the wheel fork 64 counterclockwise through the link 66. This compensates for the increase in the minimum distance a of the rake means 25 from the ground, which is caused by the change in the angle of the rotor axes with the vertical. In both of the two structures described above the wheel height is automatically changed as the rotor axis angle changes, the reason being that the end of the screw spindle 17 is stationary. Fig. 3 shows an amended embodi¬ ment of a part of the adjustment mechanism, enabling the wheel height to be changed independently of the rotor in- clination. In this amended embodiment the screw spindle 17 is hollow and surrounds another screw spindle 70 having the same pitch, which is threadedly engaged with a nut 77 mounted on the end of the screw spindle 17. In this struc¬ ture it is the end of the inner, axially adjustable screw spindle 70 which is connected with the angle lever arm 41 in fig. 1 and with the link 68 in fig. 2. This connection point is thus stationary here too, as long as the inner spindle does not rotate, but is adjustable. The details of the structures shown and described can 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 tedder having a main frame (10) intended for suspen- sion from a tractor and a carrier beam (11) which is pivo¬ tally connected with a main frame about a horizontal axis (13), a plurality of rake rotors (21), which are rotatable about their respective substantially vertical axes, being suspended from said carrier beam, each of said rake. rotors being supported by a travelling wheel (34) whose height position with respect to the carrier beam is adjustable by means of a height adjustment means slidable in parallel with the rotor axis, said tedder having an angle adjust¬ ment mechanism (15-20) preferably activatable- from the driver's seat of the tractor to pivot the carrier beam, c h a r a c t e r i z e d by an angle lever (39, 41; 54, 67) which is rotatable about an axis (40; 53) stationary with respect to the carrier beam (11), one arm (41; 47) of said angle lever being so connected with a member (17) stationary with respect to the main frame (10) that move¬ ment of the carrier beam with respect to the main frame causes rotation of the angle lever, whose other arm (39; 54) is so connected with the height adjustment means (36; 55-63) that said means is displaced upon rotation of the angle lever. 2. A tedder according to claim 1, c h a r a c t e r ¬ i z e in that the connection between the first arm (67) of the angle lever (54, 67) and the member (17) stationary with respect to the main frame (10) is established by means of a link (68) arranged between the arm and the point. 3. A tedder according to claim 1, c h a r a c t e r - i z e d in that the connection between the first arm (41) of the angle lever (39, 41) and the member (17) stationary with respect to the main frame is established in that the arm (41) is provided with a slot (42) receiving a pin (43) which is firmly connected with the stationary member (17). 4. A tedder according to claim 1, 2 or 3, c h a r a c ¬ t e r i z e d in that the location of the point articu¬ lated to the first arm of the angle lever is adjustable by means of a height adjustment mechanism (70, 71) activat- able from the driver's seat of the tractor. 5. A tedder according to any of the preceding claims, c h a r a c t e r i z e d in that the angle adjustment mechanism is formed by a screw spindle (70) which is ro¬ tatable from the cab of the tractor and cooperates with a nut (71) connected with the carrier beam. 6. A tedder according to claim 5, c h a r a c t e r ¬ i z e d in that the screw spindle (70) is blocked against displacement in its longitudinal direction, and that the end of said spindle forms the point articulated to the first arm of the angle lever. 7. A tedder according to claim 5, c h a r a c t e r ¬ i z e d in that the angle adjustment mechanism further includes a screw spindle (17) rotatable from the cab of the tractor, and that this second screw spindle cooperates with a nut (16) connected with the carrier beam such that said nut is displaced by rotation of the screw spindle, and that the end of said second spindle forms the point connected with the first arm (41; 67) of the angle lever. 8. A tedder according to claim 7, c h a r a c t e r ¬ i z e d in that the screw spindle (17) of the angle ad¬ justment mechanism is hollow, and that the screw spindle (70) of the height adjustment mechanism is arranged inside and coaxially with the hollow spindle and cooperates with a nut (70) firmly mounted on the end of said spindle. 9. A tedder according to any of the preceding claims, c h a r a c t e r i z e d in that the carrier beam (11) is secured on one end of a first arm (12), whose other end is pivotally secured to the main frame (10, 14), and that a second upwardly extending arm (15) is additionally se¬ cured to the carrier beam, said arm (15) rotatably mount¬ ing the nut (16) cooperating with the screw spindle (17) of the angle adjustment mechanism. 10. A tedder according to any of the preceding claims, wherein the carrier beam (11) contains a through shaft (52) for operating the rake rotors (21), c h a r a c - t e r i z e d in that the first arm (67) of the angle lever (54, 67) is firmly mounted on a control shaft (53), which is rotatably journalled in the carrier beam and extends in parallel with the drive shaft past all the rotor shafts and carries a second arm (54) opposite each of these, which is connected with a rod (55), which is preferably arranged on the exterior of the carrier beam and is slidable in parallel with the rotor axis, so that said rod (55) is displaced by rotation of the control shaft, said rod carrying a roller (58) which is in rolling contact with one or the other of two flanges (59) on a sleeve (48), which carries the rotor arms (24) and is slidable on, but fixed against rotation with respect to the rotor shaft (49), said flanges being located above a rotor hub disc (22), a second pair of flanges being pro- vided below this disc on the sleeve, said second pair of flanges having interposed between them a second roller (60) whose shaft is connected with the height adjustment means (61) . 11. A tedder according to any of claims 1-9, wherein the drive shaft for the rake rotors (21) contained in the carrier beam (11) is divided into sections between the rotor shafts (26), c h a r a c t e r i z e d in that the rotor shafts (26) are hollow, and that the height adjust¬ ment means are formed by a slidable rod (36), which is arranged in each rotor shaft and whose upper end protrudes from the carrier beam (11), and are firmly connected with each other and articulated to the second arm (39) of the angle lever (39, 41), which is common to all rotors (21).

Inventors: HANSEN JENS CHRISTIAN, HANSEN, JENS, CHRISTIAN
Applicants: TAARUP AS MASKINFAB, MASKINFABRIKEN TAARUP A/S
Application year: 1993
Main classification: A01D78
IPC codes: A01D78