FI116189B - drawing arm - Google Patents

Description

116189

VE TOWAR I

The invention relates to a drawbar for a three-point attachment of a vehicle comprising: - an elongated arm portion, - a ball joint at one end for attaching the drawbar to a vehicle having a hinged ball and corresponding sleeve with sliding surfaces, and - on the link arm, the ball joint shell portion is integrated into the shaft portion and the ball joint is removably mounted on the shell portion.

Much of the drawbar according to the preamble is described, for example, in Finnish patent application 20025008. The drawbar 15 in question is part of a three-point linkage used in vehicles and especially in tractors. The drawbar is an elongated body with opposite ends having means for attaching the drawbar to the vehicle and in turn for attaching the implement to the drawbar. The shown link arm is manufactured by first machining and quenching the arm portion 20, and then welding separately manufactured members such as a ball joint and a clutch grapple at the ends of the arm portion.

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'/ ·' · Normally the coupling grapple can be securely welded to: · 25 parts without fear of damage or deformation. The coupling grapple also lacks the actual lubricated sliding surfaces.

.. *. Instead, the ball joint is in fact a bearing which, ···. additional parts include a ball joint and a shell part. Compared to the coupling grapple, the ball joint shell portion is thin and may be deformed by welding. The articular ball can also be damaged * ;;; Tua. The ball joint is also normally lubricated, whereby the heat of the · ··· welding may burn off some of the lubricating grease. In addition::: Welding is a separate step of its own and the weld seam forms a point of discontinuity in the finished drawbar, which is - ,, · 35 disadvantageous to femininity.

»116189 2 U.S. Patent No. 6352123 discloses a draw bar having a detachable articulated ball. The articulation ball is threaded into the shell part of the shaft and turned into place. However, the core invention relates to the sliding surfaces of the ball joint shell part and to their hardening. Due to its removability, the articulation ball has only a narrow sliding surface and the shell part must be open. This weakens the structure of the ball joint and may cause the ball to detach during use. In addition, lubrication of the ball joint is difficult and incomplete.

10

The object of the invention is to provide a new type of drawbar which is more durable and simpler to manufacture and operate. Characteristic features of the present invention will be apparent from the appended claims. In the drawbar of the invention 15, the ball joint is provided as a part of the shaft portion, thereby avoiding the use of separate ball joints and especially welding. At the same time, the ball joint becomes more durable. In addition, in order to enable the manufacture of such a ball joint, the joint ball has unexpectedly been arranged to be removable. In this case, the shaft portion with the shell portion can be made to the end and only then finally the articulation ball is inserted into the • shell portion of the drawbar. The design also allows for a ball joint • · ·. * '! checking the condition and even replacing the articulation ball. The shell part of the ball joint and the joint ball are arranged such that the joint ball; 25 can be installed or removed without tools. Nonetheless, the impact of the solution on the function of the ball joint or the durability. is non-existent. Instead, the end result is a stronger and easier-to-produce drawbar.

'1) 30 The invention will now be described in detail with reference to • · ·; attached drawings illustrating some embodiments of the invention,::: where: • · * ·

Fig. 1a is a side view of the drawbar according to the invention;

Figure Ib shows a view from above of the drawbar la, 3 116189

Figure le shows a modification of the end of the drawbar of Figure Ib,

Fig. 2a is a view of the ball joint side end of the link arm of the invention without the articulation ball,

Figure 2b shows the first 5 steps of installing the articulated ball of the invention,

Figure 3a shows the second step of installing the articulated ball of the invention,

Figure 3b shows the third step of installing the articulated ball of the invention.

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Figures 1a and Ib show a drawbar according to the invention, generally designated by the reference numeral 1. The drawbar is intended for three-point attachment of a vehicle and comprises as main structures an elongated arm portion 3, a ball joint 2 at a first end 15 and a coupling member 4 at the other end. most commonly to the mounting pin on the tractor (not shown). Correspondingly, the coupling means is provided with a working machine, the position and position of which with respect to the vehicle is changed by means of a three-point 20-point bracket. In Fig. 1a, the coupling members 4 consist of a coupling groove 4 'which enables quick attachment of the implement. Here, the coupling grapple 4 'is secured to the arm portion 3 by welding. In addition, the arm portion may have various attachment openings 5 and, if necessary, other members such as a support flange (not shown). 25 In practice, the drawbar is made of good quality flat steel with machining holes for lifting rods and side guides and other members.

The ball joint is functionally a bearing. In practice, the ball joint 2 of the traction arm 30 1 has a hinged ball member 8 having a hinged ball 6 and a corresponding sliding surface 7. Thus, in addition to the height direction, the drawbar fitted to the fixing pin can also be moved laterally. Hereby, for example, the distance between two parallel arms can be varied.

4, 116189

According to the invention, the shell part 8 of the ball joint 2 is unexpectedly integrated into the shaft part 3 and the joint ball 6 is removably mounted in the shell part 8. That is, the shell part is an integral part of the shaft part, thereby avoiding the use of a separate ball joint. In addition, the formation of a discontinuity at the end of the drawbar, where the stresses are high, is avoided. Furthermore, damage to the articular ball is avoided and at the same time easy maintenance is achieved, which is impossible in the prior art.

Figure 2a shows the end of a draw bar according to the invention in which a ball joint is provided. According to the invention, the shaft part 3 is an induction hardened metal body, the integral shell part 8 of which comprises sliding surfaces 7 before the shaft part 3 is hardened. In other words, the sliding surfaces are machined into flat steel, after which the shaft portion can be induction hardened. Then the ball joint area is equally strong compared to the rest of the arm. In addition, the sliding surfaces can be easily hardened, which means that their wear is minimal. In this case, the joint ball is mainly worn, which allows the ball joint to be renewed by simply replacing the ball joint 20. If necessary, after the induction hardening of the shaft portion, the sliding surfaces may be machined or otherwise treated. With rapid induction hardening and subsequent targeted cooling, the surface portions and sliding surfaces of the shaft portion can be precisely hardened to the desired hardness. Nevertheless, the inside of the shaft portion 25 is tough, which improves the strength of the shaft portion.

The integrated shell is facilitated by the ability to detach the articular ball. According to one embodiment, the articulation ball 6 consists of two parts 9, and 9 ', which are arranged to be detached 30 alternately from the housing part 8. Thus, in practice, the parts together form a articulation ball which is securely held inside the housing. Nevertheless, a single portion of the hinged ball may be removed from the shell portion, whereby the entire hinged ball may be removed. Naturally, the same principle is implemented in the articulation of a ball joint.

116189 5

For attachment to the retaining pin, the articulation ball 6 includes a through hole 10 shown in Figure 1a. According to the invention, each part 9, and 9 'of the hinged ball 6 is a rotational body relative to the through hole 10, forming a hemisphere. The parts are thus symmetrical, which improves their durability and facilitates their installation. Further, the parts 9 and 9 'are substantially similar to each other, whereby their order of installation is insignificant.

10 In known ball joints, the shell portion is uniform and covers the entire ball joint. However, according to the invention, the articular ball is removable. To allow removal, at least one edge of the sliding surface 7 of the shell portion 8 has two bevels 11 and 11 '. The bevels 11 and 11 'are disposed on opposite sides of the portion 9 or 9' to mount it on the shell portion 8 or to remove it from the shell portion 8. In a suitable position, the bevels allow the hinged portion to be removed from the shell portion simply without tools. The chamfering can also be performed on both sides of the shell portion, whereby the articulated ball parts can be removed on both sides of the stem portion.

The required bevels are small and have no impact on ball joint function or durability. Preferably: the bevels are disposed on the shell portion such that the portion is mountable or removable when rotated to a position where the centerline of the through hole is substantially parallel to the plane defined by the stem portion. This embodiment is illustrated in Figures 2a to 3b. In practice, the length of the bevel 11 and 11 'is equal to or greater than the dimension parallel to the through hole of the parts 9 and 9'. In this case, the part fits snugly into the housing part, with the bevels guiding the part, especially during installation. On the other hand, the bevels can be machined::: on any side of the arm and at any angle, also in the longitudinal axis.

Figures 2a to 3b illustrate the formation of a ball joint according to the invention. Figure 2a shows only the end of the draw bar 116189 6, which forms the shell portion 8 with its sliding surfaces 7. In addition, the shell portion 8 is machined with bevels 11 and 11 'and the draw bar is tempered. Next, the first portion 9 is positioned at the bevels inside the shell portion 8. This is illustrated in Figure 2b. When the first part 9 is inside the shell part, it is turned to the position shown in Fig. 3a, whereby the second part 9 'can be mounted inside the shell part 8 in a first way. This is illustrated in Figure 3b. With both parts inside the shell part 8, the articulated ball thus formed can be rotated to the position shown in Fig. 1a and mounted on 10 vehicles. The through hole is then transverse to the longitudinal axis of the drawbar. The removal of the articular ball is performed in the reverse order. Before fitting the link arm, the ball joint can be lubricated through the grease nipple 12 (Fig. 1a and Ib). The grease nipple can also be mounted above or below the drawbar. Thus, a lubricant assembly 13 is provided in the shell 8 integrated into the crown member 3 to lubricate the ball joint 2. The lubricant assembly 13 is shown in dotted lines in Figure 1a.

Fig. 1c shows another embodiment of the drawbar 20 according to the invention, in which the coupling members 4 consist of a ball joint 2 'integrated into the shaft portion. That is, both ends of the shaft portion have ball joints. Thus, the drawbar can be made completely without welding.

• · * * »i I * * · I · l. ·. 25 Examples are the 't · drawbar made of flat steel described above. However, the cross-sectional shape of the shaft may vary '!!! and may be, for example, square, rectangular, or elliptical. The drawbar may also be telescopically extendable in a known manner.

··: 30 i <t

The drawbar of the invention is easier to manufacture.

; However, the traction arm and, above all, the ball joint strength is better. The ball joint is also easy to maintain and • replace if necessary.

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Claims (10)

A towing arm, which is intended for a three-point attachment of a vehicle, and which towing arm (1) comprises 5. an elongated arm portion (3), - a ball joint (2) at the first end of the arm portion (3) for attaching the towing arm (1) to the vehicle, in which there is in the ball joint (2) a hinge ball (6) and a housing part (8) including against this swiveling sliding surfaces (7), and 10. clutch means (4) at the other end of the arm part (3), where in the pull arm the sheath portion (8) of the ball joint (8) is integrated into the arm portion (3) and the hinge ball (6) is removably arranged in the sheath portion (8), characterized in that the hinge ball (6) consists of two parts (9,9 '), which are arranged to alternately be mounted or dismounted in the housing part (8). 2. A towing arm according to claim 1, characterized in that the articulation ball (6) comprises a through-going shark (10), relative to which the bed parts (9,9 ') of the articulation ball (6) are a rotary body which forms a half of the ball. A tension arm according to claim 1 or 2, characterized in that the parts (9,9 ') are substantially the same. • «· i i i •« »· 4. A towing arm according to any one of claims 1-3, characterized in. provided that at least at one edge of the sliding surface (7) of the housing portion (7) there are two bevels (11,11 ') which are arranged; on the opposite side of the part (9,9 ') for its mounting in the housing part • * · Ien (8) or disassembly from the housing part (8). 5. A tensioning arm according to claim 4, characterized in that the bevels (11,11 ') are arranged in the housing part (8) so that the part (9,9') can be mounted or removed when it is rotated to a position where the throughline of the heel (10) is substantially 1 in the direction determined by the level of the arm portion (3). ίο 116189 A tensioning arm according to claim 4 or 5, characterized in that the length of the bevel (11,11 ') is equal to or greater as measured on the part (9,91) in the direction of the through-going heel (10). 57. A tensile arm according to any one of claims 1-6, characterized in that the arm part (3) is an induction hardened metal piece, where the sliding surfaces (7) of the input continuous housing (8) are arranged before the induction hardening of the arm part (3). A tensioning arm according to any of claims 1-7, characterized in that a lubricant connection (13) for lubricating the ball joint (2) is provided in the housing part (8) integrated in the arm part (3). 9. A tensioning arm according to claim 8, characterized in that a lubricating nipple (12) or the like is provided for the lubricant connection (13). 10. A towing arm according to any one of claims 1-9, characterized in that the coupling means (4) are made of it in the arm part (3). , ·. integrated ball joint (2 '). »1 · t · *» · »· · · · · 1 111» • »· • · • I> I 1 1» »·» t 1 · • · • · t (1 • 1 <* · • · · »» * ·