FI92366C - Control mechanism for the inclination of a tractor's towing arm - Google Patents

Description

S TOM ΚΑΝΙ SMI 92566 ON THE TRACTOR TILT TILT

The invention relates to a mechanism for adjusting the inclination of a tractor drawbar, comprising a screw lifter comprising a drawbar carrying a drawbar and 5 threaded counter-sleeves, the second component of which is arranged to be rotated by means of a ratchet. for using and sååtåmiseksi 10 the height of the drive shaft, and wherein koteion and ensiohammaspyorån the ballot is mååråttyå angle suureraman rotation of eståvå lock member kåsittåen axially movable lock tongue tied ensiohammaspyoråån and SITA corresponding to the column bound to the housing, and wherein the mechanism includes a kiertåmållå kåytettåvå 15 woodwork transfer member lock the tongue to release the kåsittåen axis positioned pin and an oblique surface fitted thereto bound to the primary gear and a rotating member comprising said pin on the shaft and opposite responses mol on both sides of the oblique surface.

20

The adjustment mechanisms for tilting the tractor drawbar are described in German patent publications DE 3714496 (= US 4,712,445), 4022343 and 2656337. Generally, the gearbox of a screw hoist is locked by locking it in place with a suitable latch 25. However, this has the disadvantage that the telescopic arm between the crank and the gear unit wears out and most often fails in use when the torque-loaded extension is used telescopically in connection with the lifting and lowering of the drawbar. Indeed, the former German patent publication 30 discloses as a solution a locking device arranged in the gear itself, which leaves said shaft of the gear drive shaft unloaded when it is not rotated by hand from the crank.

Said locking device comprises a locking member formed between the primary gear and the housing, comprising a collar part arranged on the shaft and provided with a locking tongue which is moved in the axial direction. In the rest position, the spring presses the locking tongue into the recess in the housing, which prevents the primary gear from rotating, so that the forces do not transfer from the primary gear to the shaft driving it 92366. The same collar part is provided with oblique surfaces which are driven by a pin on the shaft, whereby thanks to the oblique surfaces the collar part moves in the axial direction, pulling the locking tongue out of its recess, whereby the pin 5 can be rotated from the primary gear.

The above-mentioned known locking member is remarkably complex, comprising a large number of parts for carrying out the function. The object of the present invention is to provide a considerably simpler and more technically advantageous adjusting mechanism by means of which the primary gear can be locked in a corresponding manner without the drive shaft and the telescopic arm being loaded. The characteristic features of the delivery mechanism according to the invention are set out in the appended claims. The invention 15 is based, firstly, largely on the realization that the locking can only be unidirectional, since the torque produced by the screw hoist via the gearbox is always parallel due only to the weight of the load on the drawbars. As a result, the direction 20 opposite to the locking direction can be utilized by forming a lifting member operating in this direction. This can be formed by means of an inclined surface formed on the primary gear and the shaft pin used by it, whereby the locking member is made very short in the axial direction.

The invention will now be described with reference to the accompanying drawings, in which a control mechanism for tilting a tractor drawbar according to the invention is shown.

Figure 1 shows an overview of the tilting adjustment mechanism of the tractor drawbar.

Figure 2 shows the gear mechanism of the gear mechanism with its locking devices in partial section.

Figure 3 shows two other operating modes of the locking member with respect to Figure 2.

Figure 4 shows the main components of the locking member as an exploded view.

Figure 5 shows the mentioned operating modes schematically.

3 92366 Referring now to the drawings, Figure 1 shows a part of an agricultural tractor comprising body and body parts as well as a drive arm adjustment mechanism. Each drawbar 1 is raised and lowered by the lift arm 12 by means of suitable intermediate arms, one of which is provided with a screw lifter 9 for adjusting its height and thus further the relative inclination of the drawbars 1. Figure 1 thus shows only this height-adjustable drawbar 1, the main components of which are a screw lifter 9 and a gearbox 3 arranged below it, the lower part 23 of which is attached to the drawbar 10 by a bolt 24. The screw nozzle 3 rotating, whereby the length of the screw lifter 9 changes. The gear 3 is driven by a crank 22 which rotates through a cross joint 21 a telescopic arm 19 which further rotates the tooth 15 from the primary gear shown below via the second cross joint 20.

The gearbox 3 is built into its housing, which comprises an upper part 5 and a lower part 6, which includes the above-mentioned fork-like fastening part 23.

As mentioned above, the weight caused by the load on the drawbar 1 pulls the screw lifter 9, which causes a torque in the sleeve 10. This must be locked in the gearbox 3 itself if the telescopic arm 19 is to be unloaded.

• Referring to Fig. 1, Fig. 2 shows the gear mechanism 3 and the associated components of the only drive mechanism. The housing is in two parts comprising an upper part 5 and a lower part 6, to which 30 the above-mentioned fastening part 23 is shown as cut away. The screw sleeve 10 is rotated by an outgoing shaft 11 connected to a secondary gear 8. This is driven by a primary gear 7, which is rotated by a shaft 2 by means of a special mechanism. The axle 2 is rotated via a cross joint 20 by the above-mentioned tele-35 scoop arm 19.

In Fig. 2, the gearbox is shown in the locking position, i.e. no rotational torque is applied to the shaft 2 via the telescopic arm 19, and the telescopic arm is thus free. The torque rotating the shaft 11 due to gravity 4 92366 is transmitted to the secondary gear 8, which tends to rotate the primary gear 7. However, it is pressed downwards by the spring 28 so that the locking tongue 30 therein is located in the lower part of the housing 5 whereby the torque is canceled in the housing via the mating surfaces 31 and 33.

The primary gear 7 is otherwise freely rotatable on the shaft 2, but the spring 28 and the pin 26 together with the abutment surfaces 10 33 and 35 limit its rotation about the shaft 2.

The spring 28 is attached to the flange 40 on the shaft 2 and at one end to the primary gear 7. It tends to both rotate the primary gear and push it down to the locking position. The primary gear 7 moves out of the locking position when the 15 shafts 2 are rotated, whereby the pin 26 causes a movement from the primary gear 7.

In Fig. 3a, the shaft 2 is rotated in the working day, whereby the pin 26, when sliding along the oblique surface 34, at the same time forces the first gear 20 and with it the locking tongue 30 up to the Kolosta formed by the surfaces 31 and 32 in the lower part 6 of the housing. 35, whereupon it begins to rotate from the primary gear 7, which further rotates from the secondary gear 8 to lower the screw lifter. 25

In the case of Fig. 3b, the shaft 2 is rotated counterclockwise, whereby the pin 26 pushes the upper part of the locking surface 33, whereby the locking tongue 30 can slide along the inclined surface 32 of the lower part 6 of the housing. When rotating counterclockwise, the primary gear 7 is allowed to move 30 back and forth in the axial direction as the spring 28 is compressed. In this way, the screw lifter can be extended.

The parts of the locking mechanism are shown in detail in an exploded view in Fig. 4. The shaft 2 is axially positioned in the housing as the flange 40 rests on the upper part 5 of the housing and the lower part of which protrudes up to the bottom of the hole in the lower housing 6. The shaft 2 has a transverse hole 25 into which a pin 26 is inserted to transmit force from the shaft forward.

5,92636

Said surfaces 32 and 31 are milled into the lower part 6 of the housing, forming said recess and locking abutment surface 31 and a second oblique surface 32. The primary gear 7 comprises a lower part with a locking tongue 30. On this other side there is a abutment surface 33 33 which acts as a locking surface 31 against that as a mating surface when the pin 26 rotates from the primary gear 7. On the opposite side, at the very bottom of the cam 30, there is a mating surface 35 for rotating the primary gear 7 by means of the pin 26 in the opposite direction. Here, the sprocket includes two lock-10 tongues 30, the openings between which each form mating surfaces 33 and a first oblique surface 34 for lifting the primary gear upwards.

Figure 5 further schematically shows the operation of the locking mechanism 15. Figure 5c corresponds to the case of Figure 2 and cases a and b correspond to cases 3a and b of Figure. In the figures, the circumferential surfaces are thought to be opened in a straight line, whereby the operation shows the linear array movement in the plane of the paper. In Fig. 5c, the primary gear 7 tends to rotate in its working day, during which it transmits a force 20 to the lower part 6 of the housing via the surfaces 33 and 31. No torque is transmitted to the pin 26 and thus to the shaft 2.

If it is desired to operate the screw lifter by means of the crank 22, its rotational movement causes a force on the pin 26. In the case of Fig. 5a the pin 25 26 starts to move to the left along the surface 34, finally ending on the abutment 35 as shown, the locking tongue 30 can be pushed forward from the primary gear. When rotated in the opposite direction, the pin 26 is pushed through the abutment-30 surface 33 from the primary gear 7 in the other direction, allowing the locking tongue 30 to slide along the oblique surface 32 of the housing. In particular, it is clear from Fig. 5c that with this construction the inclined surfaces 32 and 34 necessary for raising the locking tongue 30 of the primary gear 7 are obtained almost overlapping, whereby the construction height remains low.

Claims (8)

A tilt adjustment mechanism for a tractor drawbar (1) comprising a screw lifter (9) comprising a screw rod (4) and a threaded counter sleeve (10) carrying the drawbar (1), the second component of which is arranged to be rotatable via a gear (3) 6) located primary and secondary gears (7, 8), of which the primary gear (7) is connected to a shaft (2) rotated by a crank (22) for operating the screw lifter (9) and adjusting the height of the drive arm (1), and wherein (5, 6) and the primary gear (7) include a locking member (30, 31) preventing anti-rotation beyond a predetermined angle, comprising an axially displaceable locking tongue (30) connected to the primary gear (6, 32) and a corresponding recess (31). ), and wherein the mechanism includes a rotatably operable transfer member (26, 34) for disengaging the locking tongue (30) from the recess (31, 32) comprising a pin (26) disposed on the shaft and an oblique surface (34) disposed thereon. ) connected to a primary gear (7) and a rotating member (26, 33, 35) comprising said pin (26) on a shaft (2) and opposite stops (33, 35) on both sides of an oblique surface (34), characterized in that the locking member (30, 31) is adapted to be unidirectional by forming in the recess (31, 32) only one-way locking surfaces (31, 33) corresponding to the torque generated by the 2nd draft of the screw lifter (9) and providing the recess with a second oblique surface (32) which lifts the locking tongue (30) from the recess (31, 32) in the opposite direction, and that said axial transfer member formed by the pin (26) and the oblique surface (34) is likewise formed unidirectionally in the locking direction of the locking member (30, 31). The actuating mechanism according to claim 1, characterized in that the recess (31, 32) is formed in the lower part (6) of the housing (5, 6) open upwards and the locking tongue (30) in the lower part of the primary gear (7), respectively. A setting mechanism according to claim 1 or 2, characterized in that the inclined surface (34) of the primary gear (7) and the pin (26) driving it 7 92566 are arranged below the primary gear (7). Adjusting mechanism according to claim 1, 2 or 3, characterized in that the shaft (2) comprises a spring (28) adapted to press the locking tongue (30) into its recess (31, 32) and further rotate it in the locking direction. Release mechanism according to one of Claims 1 to 4, characterized in that the recess (31, 32) is machined directly into the structure of the housing (5, 6). Actuating mechanism according to one of Claims 1 to 5, characterized in that the first oblique surface (34) and the stops (33, 15 35) are machined directly into the structure of the primary gear (7). 6 92366 Adjustment mechanism according to one of Claims 1 to 6, characterized in that the first oblique surface (34) in the primary harrow sprocket (7) and the second oblique surface (32) in the housing (5, 6) are arranged axially partially overlapping. 8 92366