HK1025611B - Tooth arrangement - Google Patents

Description

The present invention relates to a tooth arrangement used in excavators, for example, attached to the lower edge of the bucket. The tooth arrangement consists of two parts, one part being attached to the excavator bucket by welding or some other means, and constituting a male part. The other part of the tooth arrangement which is to constitute the part actually working the ground is the female part. The two parts are joined together and, when joined, produce a transverse aperture running through the arrangement. A locking body is then placed in said aperture. It has been found that when the exchangeable working part of the tooth arrangement becomes worn, it becomes unstable due to the properties of the transverse aperture and the locking body.

A prior art tooth arrangement of the type here concerned is known from SE-A-429 051 , c f. also US-A-2 716 822 and DE-A-3 315 024 .

The object of the present invention is to eliminate said instability and this is achieved by using an aperture composed of an intermediate part and two identical end parts of the same width, the intermediate part, however, having greater width. A locking body is developed for this aperture, said body comprising two elongate parts located parallel with each other and having flat surfaces opposite each other. The width of the locking body is adapted along its length to fit said aperture. The two flat surfaces are provided with one or more outwardly directed spacers restricting the approach of the two flat surfaces. The space between the two flat surfaces is filled with a resilient material such as vulcanized rubber. It has been found advantageous to provide each of the two parts of the locking body with a spacer at each end and a spacer between them. In this way the approach of the surfaces towards each other is restricted, thereby eliminating the drawback of an unstable working part of the tooth arrangement.

It is advisable for the tip of the male part to have a cross section in the shape of a T, for the tip to be as stable as possible and for the innermost end of the female part to be designed to fit the tip of the male part so that the two parts assume a position in relation to each other which is as immovable as possible. Instability of the exchangeable part in relation to the fixed part is thus also reduced.

The present invention will be described in more detail with reference to the accompanying drawings, in which

Figures 1-2

show a complete tooth arrangement viewed from two different directions,

Figures 3-4

reveal the relationship between the locking body and the transverse aperture, certain parts of the exchangeable part having been removed,

Figures 5-6

show the exchangeable part in the tooth arrangement,

Figures 7-8

show the non-exchangeable part of the tooth arrangement,

Figure 9

shows the locking body with resilient material,

Figure 10

shows the locking body without resilient material,

Figures 11-12

show the two fixed parts in the locking body,

Figure 13

shows a cutter provided with tooth arrangements in accordance with the present invention,

Figure 14

shows the aperture in the female part,

Figure 15

shows the tip of the male part, and

Figures 16-18

show the female and male parts joined together.

The drawings show a tooth arrangement 5 comprising a male part 2 intended to be welded to a cutter or the edge of an excavator bucket 6. Said male part is provided with a tip 26 for insertion into an aperture 24 in the female part 1. The female part 1 is a part for working the ground, which can be exchanged when it has become worn. The male and female parts form an aperture 3 situated on each side of the inserted tip 26. Between these two apertures 3 is an intermediate aperture. The two apertures 3 are identical and are arranged immediately opposite each other in two side walls of the female part. Between the two apertures the upper surface of the tip 26 of the male part 2 forms part of the intermediate aperture 25 and the remaining part of the intermediate aperture 25 is formed by the intermediate wall parts situated between the side walls of the female part 1. The two apertures 3 are narrower than the aperture 25. The apertures 3 are formed in the wall parts 22 and 23. A locking body 4 is placed in the aperture 3 and 25, this body comprising two metal parts 7 and 8, each having opposing flat surfaces. Each part 7 and 8 is provided with an intermediate part 9 and 10, respectively, and two end parts 11, 12 and 13, 14, respectively. The two flat surfaces are provided with spacers. Thus the part 7 has spacers 16 and 17 at its ends 11 and 12 and a spacer 15 at its intermediate part 9. As to part 8, it is provided with spacers 18 and 19 at its ends 13 and 14 and with a spacer 20 at its intermediate part 10. The space between the surfaces of the bar-like parts shown in Figure 10 is filled with a resilient material which may consist of vulcanized rubber. The locking body 4 shown in Figure 9 can thus be influenced in such a way that both flat surfaces of the parts 7 and 8 can move towards and away from each other. However, the parts 7 and 8 can never approach each other so far as to come into contact. The spacers ensure that, at maximum compression, the two flat surface will still be a certain distance from each other.

If the locking body 4 according to Figure 9 is inserted in the aperture 3 and 25, the two parts 7 and 8 will be pressed together so that the locking body can be inserted through the aperture 3. When the locking body is fully inserted into the aperture 3 and 25 the two parts 7 and 8 will move apart so that the intermediate part of the locking body adjusted to the aperture 25 and the ends to the apertures 3.

When a tooth arrangement is in operation the parts 7 and 8 will of course approach each other. However, thanks to the spacers, the locking body will have such a width than any instability in the exchangeable part of the tooth is avoided.

Another contribution to avoiding instability in the exchangeable part is that the tip 26 of the male part has a cross section in the form of a T and that the cross section has been made as solid as possible. This can be achieved, for instance, by making the upright of the T as long as possible and as wide as possible and suiting the innermost end 24 of the aperture of the female part to the tip 26 of the male part so that the walls of the female part at the tip of the male part abut the tip of the male part as tightly as possible.

Since the tip of the male part has a cross section in the form of a T and the innermost part of the aperture in the female part is shaped to fit this T-shaped cross section it is obvious that the transverse parts of the bar of the T will be clamped between two surfaces inside the innermost part of the female part and the actual tooth can be worn rather considerably from below without it falling off the male part.

Figures 14-18 show the actual core of the tooth arrangement, i.e. both attachment parts to a cutter and the tooth part itself have been removed. The actual core part can be used in any type of attachment part and together with any type of tooth part. The Figures thus show only the region of the tooth arrangement containing the tip of the male part and the aperture of the female part, and the transverse aperture with locking body.

It has already been explained that the male part 26 has a cross section in the form of a large T. The cross section thus has an upright and two outwardly directed cross bars which may be considered to form a yoke. The lower side of each cross bar is machined in such a way as to acquire the character of an inclined surface forming an angle with the centre line of the two bars in such a way that the surface has a shorter distance to said centre line at the upright and a longer distance at the outermost end of the bar. The interior of the female body is shaped correspondingly so that when male and female parts are joined these inclined surfaces will function as a locking device for the male and female body, thereby allowing increased wear on the actual tooth from below, without the male and female parts becoming separated from each other. These two inclined surfaces can of course be replaced with other types of surfaces filling the same function, i.e. preventing the male and female parts becoming separated from each other due to wear.

Claims (1)

1. A tooth arrangement consisting of a male part (2) and a female part (1) for attachment to a movable body (6) such as a cutter, the edge of an excavator or the like, wherein the female part (1) is exchangeable, wherein the male part (2) is attached to the movable body, wherein the male part (2) and the female part (1) together form a transverse aperture (3 and 25) where the two outer parts of the trough-running aperture are arranged in the walls of the female part (1) and where the intermediate part (25) of the transverse aperture (3 and 25) is arranged in the male part (2) wherein the male part (2) and the female part (1) are held together by an elongate locking body (4) placed in the through-running aperture, whereby the outer parts (3) of the aperture have the same dimension, which is less than the dimension of the intermediate aperture (25), and which three holes are concentric, whereby the locking body (4) comprises two, parallel and equal parts (7 and 8), each with a flat surface, said flat surfaces being opposite each other and provided with one or more outwardly directed spacers (16-19) and that resilient material (21) such as vulcanized rubber is arranged between the opposite flat surfaces, whereby the ends of the locking body (4) have a dimension for cooperation and contact with the outer apertures (3) with its both parts, and whereby the intermediate part of the locking body has a dimension cooperating with and in contact with the intermediate part (25), characterized in that the two parallel parts (7 and 8) have equal length, in that the opposite flats are of the same length too, in that the outwardly directed spacers (15-20) are placed at the flat surfaces ends and at their middle ensuring that, at maximum compression, the two flat surfaces will still be at a certain distance from each other, and in that the tip of the male part (2) is in close contact with the walls of the female part (1), thereby avoiding instability in the exchangeable part of the tooth and also that the said tip has a cross section in the form of a T with outwardly directed crossbars shaped to fit the aperture in the female part allowing increased tooth wear from below and still preventing separation of the male and female parts due to wear while the crossbars will be clamped inside the female part.