IE45835B1 - Improvements in or relating to a lift-mast assembly - Google Patents

Abstract

A. Lifting mast assembly intended to be mounted on a materials handling vehicle. and b. Assembly characterized by a means for fastening the support in two parts which constitutes both the transverse support and the fixing support, the base of the locking fastener means the movement between the masts, a fastening means being mounted on the pivoting member close to the poles so that the center of gravity of the attachment means and that of the load are in close proximity of the masts and give a stable assembly. the C. The invention applies in particular to forklift trucks. [FR2369994A1]

Description

This invention relates to a lift-mast assembly for location on load-handling vehicles such as fork-lift vehicles.

Herebefore a lift-mast assembly has been provided of the type including a pair of upright parallel masts between which an attachment carrier is constrained for upright movement relative thereto, load-handling attachments Being mounted, one at a time, on to the carrier, as required.

Also, herebefore,a two-part carrier attachment has been provided for mounting on the attachment carrier to provide for .easy and quick hitching and unhitching of attachments, ' i ) said carrier attachment comprising a’..base part attachable on one side to the attachment carrier and having on the opposite side a pivotedpart comprising two spaced arms pivoted at or adjacent to their lower ends to said base pivot mounting and being pivoted relative thereto in a controlled manner. The tops .of sgid arms are adapted to hitch on to the attachment, for example, a fork carriage having two tines extending at right angles away therefrom.,or a bucket attachment. While such a carrier attachment·, when .mounted on an attachment carrier, is advantageous in reducing the time formerly required to hitch and. unhitch attachments on to an attachment carrier, the carrier attachment suffers from disadvantages in that difficulty is experienced in uniformly manipulating the two • separate pivotal arms, and' in that the load centre, that is the centre of gravity, of the attachment plus any load thereon, is - 2 45833 some distance from the centre of gravity of the vehicle to which the lift-mast assembly is connected and therefore the weight of loads to be lifted, transported or moved, is limited if tipping of the vehicle is to be prevented. The weight of loads to be lifted can be increased if the opposite end of the vehicle is counterbalanced. This, however, strains the vehicle and is damaging to the chassis.

It is an object of the present invention to obviate or mitigate the aforesaid disadvantages.

According to one aspect of the present invention there is provided a base part having a transverse plate for location between the masts and a pivotal part having a transverse plate for receiving a load-handling attachment, each said part having side walls extending from the respective transverse plate with the side walls of each part extending towards the other part and having at their lower ends nose portions which overlap with the nose portions of the side walls of the other part, the base part nose portions flanking or being flanked by the pivotal part side plates and being pivotally interconnected therewith in a manner enabling pivotal movement of the pivotal part relative to the base part about a transverse axis, piston and cylinder means extending between the base part side plates down between the pivotal part nose portions and being pivotally connected at opposite ends to both, whereby extension and retraction of the piston' means determines the degree of tilt of a load-handling attachment mounted on the pivotal part. - 3 4 5 8 3 5 Preferably the base part is provided with rollers at opposed lateral ends for engaging the masts.

According to a further aspect of the present invention there is provided a base part having a transverse plate for location between the masts and a pivotal part having a transverse plate for receiving a load-handling attachment, each said part having, side walls extending from the respective r transverse plate with the side walls-of each part extending towards the other part and having at their lower ends nose portions which overlap with the nose portions of the side walls of the other part, the base part nose portions flanking or being flanked by the pivotal part side plates and.being i pivotally interconnected therewith in a manner enabling pivotal movement of the pivotal part relative to the base part about a transverse axis, piston and cylinder means extending between the base part side plates down between the pivotal part nose portions and being pivotally connected at opposite ends tp both, whereby extension and retraction of the piston means determines the degree of tilt of a loadhandling attachment mounted on the pivotal part.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in whichrFig. 1 is a diagrammatic side elevation of a liftmast assembly, according to the present invention, showing, - 4 45835 in-chain dotted formation, a fragmentary view of a front part of a fork-lift vehicle on which the lift-mast assembly is mounted,, and a fork carriage for mounting on said carrier; Fig. 2 is a diagrammatic front elevation of the lift-mast assembly; Fig. 3 is a diagrammatic side elevation of the carrier to a larger scale than shown in Figs. 1 and .2, .and showing, in chain-dotted formation, the outer extent of pivotal movement of an outer part thereof; and Fig. 4 is a diagrammatic front elevation of the carrier as shown in Fig. 3.

Referring to the drawings, a lift-mass assembly includes two spaced parallel telescopic masts each comprising a stationary mast section 10 and a movable mast section 11 which is carried in and lAovable relative to the stationary mast section 10. The mast sections 10, 11 of each mast are constituted by a pair of uprightly inwardly facing channel members which are parallel and the two members of one mast are braced to the.corresponding members of the other mast.

An attachment carrier 13 is constrained for upright movement between the two channel members of the movable mast sections 11, and comprises a base part 14 movable in an upright direction relative to the masts 10, 11, and a pivotal part 15 pivoted at 12 to said base part 14 for pivotal movement relative to said base part 14. The part 14 comprises a - 5 45835 pair of upright rectangular back plates, 16 from the front face of each of which a pair of spaced side plates 17 extend forwardly. Each of the outer lateral side plates 17 of the four is substantially flush with the respective edge of the respective back plate 16. - The inner side plates 17 nf the four are braced together by webs 18, and a top plate 19 extends forwardly from the back plates 16 over all four side plates 17 and is secured by welding thereto. The side plates 17 are of similar shape and in side elevation have an upright portion 17A and a downwardly and forwardly inclined nose portion 17B extending from the root of the upright portion 17A.

The pivotal part 15 comprises two pairs of side plates 20 positioned to fit partly within the pairs of side plates 17 on the base part 14. The side plates 20 of the outer part 15 are of similar shape and in side elevation have an upright portion 20A with a straight front edge and a nose portion 20B extending rearwardly from the root of the upright portion 20A,, the pivotal connection 12 between the carrier parts 14,15 being located in the portion 17B of each side plate 17 and near the bottom of the upright portion 20A of each side plate 20.

A front plate 21 extends transversely between and beyond the two pairs of side plates 20 of the pivotal part 15 at the top of the upright portion 20A thereof and with the face of said front plate 21 being flush with and attached to the ‘straight front edge of the side plates 20. The plate 21 provides a means for engaging an attachment, and thus the pivot part isof unitary construction. Hooks 22 are provided on an attachment, for example, a fork carriage 23 having tines 24 (as shown in Fig. 1), the hooks 22 being engagable by the top of the front plate 21. An anchor pin hole 25 is provided in a bottom corner of each outer lateral side plate 20, corresponding holes 26 being provided in lugs 27 on said attachment. After an attachment is hooked on to the front plate 21, the attachment is lifted off the ground and the attachment moves into a position, under gravity, in which the holes 26 align with the holes 25.

An anchor pin (not shown) may be passed through the holes 25, in each pair of side walls and in the attachment for positive anchoring if required, otherwise the weight of the attachment and any load therein holds it in position. Two hydraulic rams (Figs. 3 and 4) are provided to control movement of the pivotal part 15 relative to the base part 14. Each ram is located between a pair of side plates 17 of the base part 14 and between corresponding side plates 20 of the pivotal part 15. A cylinder 28A of each ram 28 is pivotally mounted adjacent to the top of the upright portions 17A of the side plates 17 and extends downwardly therefrom. The outer end of a piston 28B of each ram is pivotally mounted to the rear end of the rearward portion 20B of the associated side plate 20, whereby on retraction of the rams 28, the pivotal part 15 is pivoted forwardly and downwardly relative to the base part 14. On extension of the rams 28, the outer part 15 - 7 835 is pivoted upwardly and inwardly relative to the part 14.

In order that the base part 14 can constitute the attachment carrier, each outer lateral side plate 17 is provided adjacent to the top and bottom thereof with a lowfriction rotatable roller 30 mounted on a stub shaft 29, the axes of the stub shafts being at right angles to the said side plates 17. The rollers 30 serve to mn along the inner limbs of the channels of the masts 10,11, Two low-friction rotatable wheels 33 intended to run along the webs of the channels of the masts 10, 11 are carried on axles 32 in mountings 31 on the outer faces of the outer side plates 17, the axes of said wheels 33 being at right angles to the axes of the rollers 30.

In use, a lift-mast assembly according to the invention, is mounted on a load-lifting and carrying vehicle such as a fork-lift vehicle 34 (Fig. 1). Different attachments can be hooked on to the carrier 13 with the attachment to be hooked upstanding from the ground or from a surface, such as a platform or scaffolding. The vehicle is positioned so that the hooks 22 of the attachment are close to and face the carrier 13. The rams 28 are retracted causing the pivotal part 15 to pivot forwards and downwards towards the attachment. The front plate 21 is engaged I under the hooks 22 and the rams 28 are extended to cause the . part 15 to pivot upwards and rearwards. This action - 8 45835 lifts the attachment off the ground, platform or the like, and it swings by gravity about the plate 21 so that the brackets align with holes 25. Anchor pins (not shown) are than located in the anchor pin holes 25,26, if required. The g attachment can then be moved up or down the masts. The attachment can be detached by reversing the above steps.

Alternatively, hooks may be provided on the outer part of the carrier and a plate mounted on the attachment. Other interlocking means between the outer part of the carrier and each attachment may be provided without departing from the scope of the invention as defined in the appending claims.

The above-described lift-mast assembly is advantageous over known assemblies in that it provides easy coupling and uncoupling of attachments due to the unitary construction of the pivot part 15 of the carrier 13. Also it enables the centre of gravity of a load on the attachment to be nearer to the lift-mast assembly than herebefore, due to the fact that the attachment carrier of known assemblies has been replaced by the base part, suitably modified, of the known carrier attachment, thereby reducing the distance of the attachment from the masts of the assembly. This is important and has the effect that greater loads can be handled than heretofore without creating undue strain on the vehicle or the liklihood of tipping. - 9 4-5 8 3 5

Claims (5)

1. CLAI24S: 1. A lift-mast assembly for location on a load-handling ’ vehicle, comprising a pair of upright parallel masts then to be spaced transversely relative to the direction of travel 5 of the vehicle, a transverse tiltable carrier mounted between the masts for constrained movement in an upright direction relative to the masts, said carrier comprising a base.part having a transverse plate for location between the masts and a pivotal part having a transverse plate for receiving a 10 load-handling attachment, each said part having side walls extending from the respective transverse plate with the side walls of each part extending towards the other part and having at their lower ends nose portions which overlap with the nose portions of the side walls of the other part, the base part 15 nose portions flanking or being flanked by 'the pivotal part side plates and being pivotally interconnected therewith in a manner enabling pivotal movement of the pivotal pa.rt relative to the base part about a transverse axis, piston and cylinder means extending between the base part side plates down between 20 the pivotal part nose portions and being pivotally connected at opposite ends 'to both, whereby extension and retraction of the piston means determines the degree of tilt of a loadhandling attachment mounted on the pivotal part.

2. A lift-mast assembly as claimed in Claim Γ, wherein 25 the base part is provided with rollers at opposed lateral ends for engaging the masts.

3. A carrier for a lift-mast assembly having a pair of upright parallel masts, said carrier comprising a base part having a transverse plate for location between the masts and ib 45835 a pivotal part having a transverse plate for receiving a load-handling attachment, each said part having side walls extending from the respective transverse plate with the side walls of each part extending towards the other part and 5 having at their lower ends nose po.-.’tions which overlap with the nose portions of the side walls of the other part, the base part nose portions flanking or being flanked by the pivotal part side plates and being pivotally interconnected therewith in a manner enabling pivotal movement of the pivotal 10 part relative to the base part about a transverse axis, piston and cylinder means extending between the base part side plates down between the pivotal part nose portions and being pivotally connected at opposite ends to both, whereby extension and retraction of the piston means determines the 15 degree of tilt of a load-handling attachment mounted on the pivotal part.

4. A lift-mast assembly for location on a load-handling vehicle substantially as hereinbefore described with reference to the accompanying drawings. 20

5. A carrier for a lift-mast assembly substantially as hereinbefore described with reference to the accompanying drawings. F. R. KELLY & CO., AGENTS FOR THE APPLICANTS. - Π 45835