GB2234487A

GB2234487A - Lift trucks

Info

Publication number: GB2234487A
Application number: GB8917669A
Authority: GB
Inventors: Peter Wooldridge
Original assignee: NARROW AISLE Ltd
Current assignee: NARROW AISLE Ltd
Priority date: 1989-08-02
Filing date: 1989-08-02
Publication date: 1991-02-06
Also published as: GB8917669D0

Abstract

A lift truck has a chassis (10) with a front axle having front wheels (12) at its opposite ends, a carriage (14) traversable over and above the front axle, a vertical pivot carried by the carriage and carrying a mast structure (15), which has a carrier (16) movable up and down and also transversely thereon, the carrier supporting a load fork (17). The truck can handle loads forward and to the sides thereof, can operate in narrower aisles than conventional trucks and doesn't require a heavy chassis counterweight. <IMAGE>

Description

'LIFT TRUCKS' This invention relates to fork lift trucks, particularly for use in narrow aisles.

According to the present invention a lift truck comprises a wheeled chassis, a mast structure movable transversely of the chassis, means for angularly moving the mast structure about a vertical or substantially vertical axis, in use, and a load fork movable up and down the mast structure and also transversely thereof.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic plan view of a lift truck of the invention, with its load fork directed forwardly, Figure 2 is a schematic plan view of a lift truck of the invention and of substantially the same form as the truck of Figure 1, with its load fork directed sidewardly and positioned substantially within the width of the truck chassis, and Figures 3 and 4 show alternative arrangements respectively of the load fork directed to opposite sides of the truck.

Figure 1 shows a lift truck having a chassis 10 with a steerable rear wheel 11, which, in use, is driven by the motive means of the truck, and a pair of front wheels 12 at opposite ends of a front axle of the truck.

However, the truck could have four wheels and the driving and steering arrangements could be varied as required.

At a rear corner of the chassis is an operator's cab 13 containing a seat, a steering wheel and other controls for operating the truck. This part of the truck is raised above the remainder of the upper chassis surf ace, which is flat or generally so.

Across the front of the chassis a carriage 14 is traversable, the carriage movement being over and above the front axle of the truck. The carriage carries a vertical pivot for a mast structure 15 so that the mast structure can move angularly about the carriage 14 between the two extreme positions, 1800 apart, shown in Figures 3 and 4 respectively, where it is directed to opposite sides of the truck. The mast structure can be of any suitable form, such as telescopic, the nature of the mast structure forming no part of the present invention.

The mast structure has a carrier 16 which is arranged to travel up and down on the mast structure, and which supports a conventional load fork 17. As well as its up and down movement, the carrier is arranged to move transversely across the mast structure. Figures 3 and 4 show the carrier, and thus the load fork, in extreme right and left positions respectively relative to the mast structure.

All movements of the carriage, mast structure and carriage are controllable from the cab 13 and the means of carrying out such movements can be conventional.

Figure 1 shows the carriage 14 positioned slightly away from one side of the chassis, with the mast structure 15 directed forwardly and the carrier 16 at the lift hand side of the mast structure. The load fork can be used, in this position, to pick up from the ground by lowering the carrier on the mast structure to ground level. The figure shows at 18 the travel of the centre of the load fork at the extreme carrier positions.

Figure 2 shows for a similar truck, with a slightly shorter front axle, the carriage at the left hand side of the chassis, with the mast structure at 900 from its Figure 1 position and facing towards the right hand chassis side. The load fork is still at its left hand position on its carrier, and Figure 2 shows how it can carry a long load 19, part of which extends inboard of the truck. With a short load, the load fork can pick it up from the ground and move it transversely forward of the truck.

Figure 4 shows schematically at 20 how the centre of the load fork moves if it is held in position relative to the mast structure whilst the mast structure rotates through 900 The truck of the invention is thus very versatile in its ability to pick up and handle loads from ground level and to the front and sides of the chassis, as a result of a traversing and pivoting mast structure, and a traversing carrier for the load fork.

According the truck has the following benefits: i) It allows the aisles of conventional trucks to be reduced to widths not much greater than the pallet width.

ii) It can handle loads (pallets) forward of the truck and to each side.

iii) It can handle long loads.

iv) It is more flexible for outside use i.e. on uneven surfaces.

v) It combines the benefits of a counterbalance truck, a side loader truck and a very narrow aisle truck.

As illustrated, the mast structure pivot point is over the wheelbase, i.e., further back than with conventional trucks, so that the load can be positioned less forward, and obviating the need for a large counterweight on the chassis. The load fork 17 could be connected to the carrier 16 by an extending/retracting linkage if required.

Claims

1. A lift truck comprising a wheeled chassis, a mast structure movable transversely of the chassis, means for angularly moving the mast structure about a vertical or substantially vertical axis, in use, and a load fork movable up and down the mast structure and also transversely thereof.

2. A lift truck as claimed in Claim 1, wherein the chassis includes a front axle, over and above which is traversable a carriage which does not extend rearwardly of said front axle.

3. A lift truck as claimed in Claim 2, wherein the carriage carries a vertical pivot about which the mast structure is angularly movable, the mast structure having a carrier movable up and down thereon and also transversely thereof, the carrier supporting said load fork.

4. A lift truck as claimed in Claim 3, wherein said front axle of the chassis defines the front or forward end of the truck, and said carriage does not extend beyond said end so that the pivot is always within the boundary of the front axle, which defines a wheelbase of the truck.

5. A lift truck substantially as hereinbefore described with reference to and as shown in the accompanying drawings.