A device in excavating-machine buckets

Abstract

 A device in excavating-machine buckets. The bucket (10) is pivotally mounted in a yoke part (12) and is operated to perform pivotal movements by means of a pair of piston-and-cylinder units (26) mounted in the bucket.
In order to rotate the bucket the device comprises two tube blanks (28, 30) which are mounted in nesting relationship, the inner one of said tubes being secured to the yoke part (12) and to a lid (32). The device also comprises an attachment member (44), allowing the device and the bucket (10) to be mounted on a crane arm (46). Two piston-and-cylinder units (40) are mounted on said attachment member and secured to the lid (32) to operate the movements of the latter. Turning movement of the lid results in a turning movement of the inner tube blank (28) and of the yoke part (12) and the bucket (10). The outer tube blank (30) is secured to the attachment member (44). Wheels (36,38) are provided about the outer tube blank (30) to take breaking stress exerted on the tube blanks (28,30).

Description

[0001] The subject invention concerns a device in excavating--machine buckets. More precisely, the invention concerns a device for operating the bucket relative to the crane arm on which the bucket is mounted.

[0002] It is preferable that buckets mounted on excavating--machines can be operated in as many ways as possible. For instance, the bucket should be able to perform turning movements relative to the crane arm as well as tilting and tipping movements, that is, lateral pivoting movements.

[0003] Prior-art techniques provide several examples of constructions that allow versatile operation and control of excavating-machine mounted buckets. However, these constructions suffer from several drawbacks of a practical nature. As one example may be mentioned a construction allowing the bucket to perform turning movements, which construction functions according to the principle that a shaft which is provided with cogs and supports the bucket proper is operated by a rack. However, this construction has proved to be too weak as in operation the shaft is exposed to considerable breaking stress which may cause the shaft to buckle.

[0004] The purpose of the subject invention is to provide an arrangement in excavating-machine buckets according to which the bucket may be operated to perform turning and tilting movements. A bucket which is provided with the device in accordance with the invention is light and may be operated in a smooth and convenient manner. The device occupies but a small space between the bucket and means securing the bucket to the crane arm. The purposes of the device in accordance with the invention are achieved in that the bucket is pivotally mounted on a yoke part, that one or several piston-and-cylinder units are mounted both on the bucket and on the yoke part to operate the bucket movements relative to the yoke part, that the yoke part is mounted for movement about a rotational centre comprising two parts which are arranged to turn relative to each other, that one of these parts is rigidly secured to an attachment member to secure the device to a crane arm and that the second one of said parts is attached to the yoke part and that one or several piston-and-cylinder units are provided to control the relative movements of the two parts forming said rotational centre.

[0005] The invention will be described in closer detail in the following with reference to the accompanying drawings, wherein

Fig. 1 is a partly sectional view though the device in accordance with the invention,

Fig. 2 is a cross-section along line 11-11 of Fig. 1, and

Fig. 3 is a cross-section along line III-III of Fig. 1 through various details designed for the operation of the bucket turning movements,

Fig. 4 is a cross-section along line IV-IV of Fig. 1 of a mechanism devised to perform tilting movements, and

Fig. 5 is a cross-sectional view through the same mechanism in the position showing the bucket in the turned position.

[0006] A bucket 10 is provided with a device in accordance with the invention (see Fig. 1) at its upper edge. The rest of the bucket is of a conventional design and not shown in the drawings. It should be pointed out, however, that the opening of the bucket faces to the left in Fig. 1.

[0007] The bucket 10 is mounted on a yoke part 12 which consists of sheet-metal which is formed with two downwardly extending yoke members 14 which together with two lugs 16 on the bucket 10 and trunnions 18 form pivot mountings allowing the bucket to perform pivotal movements. Furthermore, the yoke part 12 is formed at one of it edges with a flange 20 which is arranged to extend into and be received in a slot 22 formed in the top wall of the bucket 10.

[0008] At the upper rear edge of the bucket and around the slot 22 there is formed a compartment with inner walls 24 in the bucket. A pair of hydraulic piston-and-cylinder units 26 are housed inside this compartment. These units are arranged for mutual cooperation and are attached to the flange 20 in the manner appearing from Figs. 4 and 5. These piston-and-cylinder units 26 allow the bucket 10 to be pivoted about its mounting shafts 18, e.g. from the position illustrated in Fig. 4 to the position illustrated in Fig. 5. This movement of the bucket 10 is known as tilting. Owing to the walled-in mounting of the hydraulic piston-and-cylinder units 26 the latter will be well protected. The connecting means of the hydraulic piston--and-cylinder units 26 are of a conventional kind and are not shown in the drawings.

[0009] The device in accordance with the invention also comprises a mechanism designed to effect the turning movements of the bucket 10. For this purpose, the yoke part 12 is secured to an inner tube blank 28, preferably by means of welding. This inner tube blank 28 is mounted for movement inside an outer tube blank 30. Between the tubes 28, 30 there is a bearing means allowing the tubes to turn relative to each other. The inner tube 28 is secured at its upper edge to a lid 32, preferably by means of bolts 34. The lid 32 also extends above and beyond the outer tube 30.

[0010] Three wheels 36 are mounted on the outer tube 30 (see Fig. 3) with an angular spacing of 90⁰ between the wheel axles so that two wheels will be positioned diametrically opposite each other and the third one towards the rear of the bucket. Diametrically opposite this third wheel, that is, towards the front of the bucket, a wheel 38 is mounted. The three wheels 36 travel in contact with the upper face of the yoke part 12 whereas the front wheel 38 is arranged to run in contact with the lower face of the lid 32. The function of the wheels is to take the breaking stress which is exerted on the rotational shaft formed by the two tubes 28, 30 , which breaking stress may be considerable during certain loading conditions and movements of the bucket.

[0011] Two hydraulic piston-and-cylinder units 40 are provided to operate and control the turning movements of the bucket 10. These units are attached at either side of a plate 42, which is part of the attachment member 44 of the device by means of which the latter is attached to the crane arm 46. The piston-and-cylinder units 40 are arranged so as to diverge in the direction of the piston rod and are attached to the lid 32 at the piston rod ends (see Fig. 2).

[0012] Turning movement of the bucket 10 is effected in the following manner. Outwards and inwards movements, respectively, of the hydralic piston-and-cylinder units 40 result r a rotational movement of the lid 32, which in turn results in a turning movement of the inner tube 28. The outer tube 30 is secured to the attachment member 44 (it may, for instance, be attached to the plate 42) and consequently it does not take part in the turning movement of the inner tube. The inner tube 28 is secured to the yoke part 12 and consequently the latter is also turned and with it the bucket 10.

[0013] As mentioned in the aforegoing the wheels 36 and 38 are arranged to absorb breaking stress which may affect the turning shaft formed by the tubes 28, 30. This breaking stress arises when the bucket digs intc- the ground or when it lifts heavy objects which may be unevenly distributed in the bucket, such as may be the case e.g. when single large boulders and the like are supported in the bucket close to one edge thereof. The possibility of performing tilting movements also results in the possible occurrence of breaking stress in ditch-digging operations which are performed with the bucket assuming an angled position. The wheels 36 and 38 are evenly distributed around the outer tube circumference in order to take breaking stress in any one direction.

[0014] The device in accordance with the invention is functionally reliable, since all sensitive components, such as piston-and-cylinder units, wheels and the like, are well protected. The device is compact - the distance from the bucket to the attachment member on the crane arm will be appr. 45 cm.

[0015] The embodiment of the invention described in the aforegoing is to be regarded as one example only and a variety of modifications and other embodiments are possible within the scope of the appended claims. The device in accordance with the invention comprises a large number of mechanical components of a conventional nature which obviously could be replaced by other components of alike function.

Claims

1. A device in buckets (10) for excavating machines, characterised therein that the bucket (10) is pivotally mounted in a yoke part (12), that one or several piston-and-cylinder units (26) are mounted both on the bucket (10) and on the yoke part (12) to operate the bucket movements relative to the yoke part, that the yoke part (12) is mounted for movement about a rotational centre comprising two parts (28, 30) which are arranged to turn relative to each other, that one of these parts is rigidly secured to an attachment member (44) to secure the device to a crane arm (46) and that the second one of said parts is attached to the yoke part (12) and that one or several piston-and-cylinder units (40) are provided to control the relative movements of said two parts (28, 30) forming said rotational centre.

2. A device as claimed in claim l, characterised therein that the rotational centre is formed by two tube blanks (28, 30) which are arranged in nesting relationship and so as to be able to perform relative turning movements, that the outer one (30) of said blank tubes is attached to the attachment member (44) and that the inner one (28) of said tube blanks is attached to the yoke part (12).

3. A device as claimed in claim 2 och 3, characterised therein that wheels (36, 38) are secured to the outer one (30) of said tube blanks and that these wheels serve as support wheels to take breaking stress exerted on said tube blanks (28, 30).

4. A device as claimed in claim 2 or 3, characterised therein that the inner one (28) of said tube blanks is attached to a lid (32), that said lid (32) extends above and projects beyond the outer tube blank (30) and that at least one support wheel (38) is provided at the outer tube blank (30) so as to abut against the lid (32).

5. A device as claimed in any one of the preceding claims, characterised therein that the yoke part (12) is provided with a flange (20) projecting into a slot (22) extending along the upper face of the bucket (10) and that the piston-and--cylinder unit or units (26) which are mounted on the bucket (10) are provided in the bucket for the purpose of operating the latter relative to the yoke part (12).

Drawing