Attachments for digger buckets

Abstract

 An attachment is provided for mounting on a digger bucket having projecting teeth. The attachment includes a jaw (10) which can be fitted over an edge of the bucket, a locking assembly (18) for holding the jaw (10) in engagement with the edge of the bucket, and load transfer means (27, 31) for transferring a significant proportion of the weight of an object being lifted to the digger teeth.

Description

Field of the Invention

[0001] This invention relates to attachments for digger buckets.

[0002] The buckets of diggers used for carrying out civil engineering and other operations have projecting teeth and it is not unknown for a digger operator to use the bucket on the front of his digger or excavator as a carrying device for heavy objects, such as manhole covers, by balancing an object to be carried on one or more of the bucket teeth.

[0003] The carrying of heavy objects in this way is hazardous and it is accordingly an object of the present invention to provide an attachment which can be mounted on a digger bucket so that heavy objects can be carried safely.

Summary of the Invention

[0004] According to the present invention there is provided an attachment for mounting on a digger bucket having projecting teeth, the attachment comprising a jaw which can be fitted over an edge of the bucket, means for holding the jaw in engagement with the edge of the bucket, a hook assembly with which an object to be carried can be engaged, and load transfer means whereby a significant proportion of the weight of the object engaged with the hook assembly is applied to the bucket teeth.

[0005] The load transfer means preferably includes a cross bar attached to the jaw and arranged so that, in use, its longitudinal axis extends parallel to the edge of the bucket, and a pair of channel-section elements carried on the cross bar at or adjacent the ends thereof, with the spacing between the channel-section elements corresponding to the spacing between adjacent teeth of the bucket.

[0006] The bucket is preferably drilled to provide an aperture spaced from the edge of the bucket and the means for holding the jaw in engagement with the edge of the bucket preferably comprises a pin carried by the jaw and arranged to pass through the aperture in the bucket.

Brief Description of the Drawings

[0007] 

Figure 1 is a plan view of an attachment for a digger bucket,

Figure 2 is a side view of one of the components of the attachment of Figure 1, and

Figure 3 shows another component of the attachment of Figure 1.

Description of the Preferred Embodiment

[0008] The attachment shown in the drawings is intended to be mounted on a bucket on the front of a digger or excavator for use in the carrying of heavy objects, for example, manhole covers.

[0009] The attachment includes a main jaw 10 (Figure 2) which is formed as a metal casting and fits over the edge of the bucket. The main jaw 10 is positioned, in use, midway between two of the projecting teeth of the digger bucket at a position in which an aperture has been drilled. The aperture is spaced from the edge of the bucket and is positioned midway between two of the projecting digger teeth.

[0010] The main jaw 10 includes a pair of parallel upper and lower limbs 11 and 12, each of which is formed with a lozenge-shaped aperture 13. The upper limb 11 is formed with a reinforcing flange 14 which extends around the apertures 13, and an anchorage 15 is positioned at one end of the aperture 13. The limbs 11 and 12 are connected by a bifurcated portion 16, the two arms of which are formed with cored holes 17.

[0011] A locking mechanism assembly 18 (Figure 3) is carried by the jaw 10 and includes a sleeve 19 formed with a bore in which a pair of springs 20 and 21 are fitted. The springs 20 and 21 act on a pin 22 which is held in engagement with the sleeve 19 by means of a collar 23 which has threaded engagement with an externally threaded formation of the sleeve 19. The springs 20 and 21 surround a reduced diameter portion of the pin 22 which is formed, adjacent its end, with a transverse bore. The locking mechanism assembly 18 also includes a handle 24 which passes through the transverse bore in the reduced diameter portion of the pin 22. The handle 24 is fitted in position after assembly of the sleeve 19, springs 20 and 21, pin 22 and collar 23.

[0012] A linch pin 25 is attached to the handle 24, and the linch pin 25 is connected by a chain 26 to the anchorage 15 on the main jaw 10.

[0013] The locking mechanism assembly 18 is normally held in permanent engagement with the main jaw 10 with the sleeve 19 within the lozenge-shaped apertures 13. When it is desired to attach the main jaw 10 to the digger bucket (not shown), the locking mechanism assembly 18 is moved out of the way and the main jaw 10 is moved so that the edge portion of the digger bucket passes between the upper and lower limbs 11 and 12 of the main jaw 10. The locking mechanism assembly 18 is then moved downwardly so that the pin 22 and sleeve 19 pass through the aperture which has been drilled in the digger bucket, thereby holding the jaw 10 in engagement with the digger bucket.

[0014] The jaw 10 is attached to a cylindrical cross bar 27 which passes through (and is fixed to) the eye 28 of a hook assembly 29. The bar 27 passes through the cored holes 17 in the bifurcated portion 16 of the main jaw 10 and is restrained from axial movement relative to the main jaw 10 by means of grub screws 30 which engage with reduced diameter portions of the cross bar 27.

[0015] Channel-section elements 31 are fixed to the ends of the cross bar 27 with their channels arranged to fit over the projecting bucket teeth. The channel-section elements contain (or can contain) spacing plates (not shown) to ensure that, when the channel-section elements 31 are fitted over the projecting bucket teeth, a close fit is obtained.

[0016] Cylindrical spacers 32 are fitted over the cross bar 27 between the main jaw 10 and the channel-section elements 31, which are held in position on the bar 27 by means of slotted nuts 33 which are tightened on to threaded end portions of the bar 27. Washers 34 are disposed between the nuts 33 and the adjacent faces of the channel-section elements 31 and cotter pins 35 are fitted outside the nuts 33.

[0017] In use, the attachment is moved into a position adjacent the edge of the bucket with the channel-section elements in register with two adjacent teeth. The operator then pulls on the handle 24 to lift the locking mechanism assembly 18 clear of the main jaw 10. The jaw 10 is then fitted over the edge of the bucket, the channel-section elements 31 are fitted over the teeth and the locking mechanism assembly 18 is then replaced so that the pin 22 and sleeve 19 pass through the aperture drilled in the bucket and the free end of the pins 22 enters the lozenge-shaped aperture 13 in the lower limb 12 of the jaw 11. The attachment is thus firmly and positively attached to the edge of the bucket.

[0018] An object to be lifted can now be attached to the hook assembly 29. As the cross bar 27 passes through the eye 28 of the hook assembly 29, the weight of the object to be lifted will be applied to the cross bar 27. The load being supported will then be transferred to the two channel-section elements 31 and thence to the projecting bucket teeth. It is thus to be noted that no significant load is applied to the jaw 10, the sleeve 19 and the pin 22. There is thus no danger of the jaw 10 becoming separated from the edge of the bucket under the action of the load being transported. The attachment of the present invention thus enables heavy objects to be transported without the hazards which can arise as a result of "hanging" a heavy object on one of the digger bucket teeth.

Claims

1. An attachment for mounting on a digger bucket having projecting teeth, the attachment comprising a jaw which can be fitted over an edge of the bucket, means for holding the jaw in engagement with the edge of the bucket, a hook assembly with which an object to be carried can be engaged, and load transfer means whereby a significant proportion of the weight of the object engaged with the hook assembly is applied to the digger teeth.

2. An attachment as claimed in Claim 1, in which the load transfer means includes a cross bar attached to the jaw.

3. An attachment as claimed in Claim 2, in which the cross bar is arranged so that, in use, its longitudinal axis extends parallel to the edge of the bucket.

4. An attachment as claimed in Claim 2 or Claim 3, in which the load transfer means also includes a pair of channel-section elements carried on the cross bar.

5. An attachment as claimed in Claim 4, in which the channel-section elements are carried on the cross bar at or adjacent the ends thereof, with the spacing between the channel-section elements corresponding to the spacing between adjacent teeth of the bucket.

6. An attachment as claimed in any one of the preceding claims, in which the bucket is drilled to provide an apertures spaced from the edge of the bucket and the means for holding the jaw in engagement with the edge of the bucket comprises a pin carried by the jaw and arranged to pass through the aperture in the bucket.

Drawing