GB2276144A - Stacker vehicle - Google Patents

Abstract

A mechanical handling vehicle 1 having forks 11 movable on a mast 10 to which is in turn movable on the chassis 1 is provided with grids 17 - 21 which run on rails 15, 16 or the like of a warehouse with racks for storing goods. In order to stabilise and guide the upper part of the mast, irrespective of the position of the mast, the guides are pivotally attached to the mast and moved by levers 22, 28 and control roller 24 moving in a slot 25 of the vehicle on the mast reciprocates. Thus guide rollers 21 are held against the rails 15, 16. <IMAGE>

Description

This invention relates to equipment for stabilising and guiding the masts of mechanical handling vehicles.

In many cases it is desirable, or essential, to guide or stabilise the mast of a mechanical load handling vehicle. This is especially the case when the height of mast and the height of lift is great in relation to the width or length of the chassis of the vehicle. Guiding and stabilising means are often required for stability and safety of the vehicle and the load. In certain cases accurate positioning and guiding of the mast is required to ensure the load may be placed with the required accuracy and that any load retrieval device may be engaged accurately with the said load.

There are many well known devices for guiding and stabilising the masts of such mechanical vehicles. For example, the top of a fixed mast may be guided by means of rollers engaging with an overhead monorail fixed to the storage building or the storage racks or other structure. Alternatively, the mast may be guided part way up by means of rollers abutting a rail, or rails fixed to an appropriate structure. Such means are often applied to machines with fixed masts, or with a substantial proportion of the height of the mast fixed.

It is well known that there is a range of load handling vehicles wherein the mast, or a substantial proportion of the mast, is fixed relatively to the chassis of the said vehicle. In addition to the said range of fixed mast machines, it is well known that there is a range of machines wherein the mast must move in order for the machine to place and retrieve a load. The movement of the mast is often in the transverse direction relative to the normal direction of travel of the chassis. This is the case where machines running in narrow aisles between rows of racks are involved.

Such machines with moving masts could well benefit from stabilising means applied to the said mast. However, the very movement of the mast renders the provision of such stabilising devices difficult.

The present invention relates to the provision of stabilising, locating and guiding equipment for use on machines and vehicles fitted with masts that move relatively to the chassis of the vehicle.

According to the present invention there is provided a number of guiding elements attached to the mast of a load handling vehicle. Said guiding elements co-operate with rails, or similar features, attached to the storage racks, or similar structure, or to the building. Said guiding elements are so mounted upon the said mast so that relative movement between the guiding elements and the mast is possible. In particular, the relative movement is so controlled as to ensure any movement of the mast causes an opposed movement of the guiding elements relative to the mast. In this manner, the spatial position of the guiding elements are maintained in a fixed, or substantially fixed, relationship to the equipment to which the mast is slideably connected. In a preferred embodiment a number of guiding elements are disposed in a substantially symmetrical arrangement about the mast.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing, referenced Figure 1, which is an isometric projection showing the essential elements of a complete vehicle incorporating the specific embodiment of this invention.

The vehicle comprises a chassis assembly 1 running on a number of wheels 2. The wheels may run directly upon the floor or be so formed as to run on rails 3. The vehicle chassis 1 incorporates diving means in order that the vehicle may move along the floor on rails in the direction of the arrows 4 and 5. The chassis may be formed with a well 6 within which runs a mast carriage 7. The said mast carriage is slideably connected to the chassis 1 and provided with means to drive the said mast carriage across the chassis in both directions shown by arrows 8 and 9. To the mast carriage there is fitted a mast assembly 10. To this mast assembly there is slideably connected a lifting carriage 11. This lifting carriage is provided with driving means so that it may move in both the directions shown by arrows 12 and 13.To the lifting carriage there is fitted a number of load engaging forks 14, or equivalent devices (not shown).

At high level there are a pair of rails 15 and 16 fixed to a suitable part of the racks (not shown) or to the building (not shown). For illustrative purposes a section of rail 16 is not fully shown.

To the mast assembly 10 there is attached a vertical shaft 17 which is pivotally connected to the said mast assembly by a number of collinear pivots 18. At high level, near the top of the mast, there is a guide arm 19 connected to the vertical shaft. Near the free end of the guide arm there is a stub axle 20 fitted, upon which a guide roller 21 is rotationally mounted. This guide roller is so positioned that it is constrained by the inner side faces of rails 15 and 16.

At low level, near the base of the mast, there is a control arm 22 connected to the vertical shaft 17. The end of the control arm remote from the vertical shaft is filled with a stub axle 23 and control roller 24 in the same manner as for the guide roller.

The distance from the axis of the upper stub axle 20 to the axis of the vertical shaft 17 is the same, or almost the same, as the distance from the axis of the lower stub axle 23 to the axis of the vertical shaft. That is, the operating radii of the guide arm and of the control arm are the same, or almost the same.

It should be noted that the operating radii can be made unequal to give the mast an inclination at certain parts of the transverse movement which counteracts the normal deflections induced by the load.

The guide roller 24 is constrained to run between guides 25 and 26 fixed to the chassis 1. In a preferred embodiment these guides are equally disposed about the longitudinal centre line of the chassis.

Hence, in the case where both the guide arm and the control arm have identical operating radii, when the mast carriage 7 and the mast assembly 10 is caused to move across the chassis, the movement of the assembly of the vertical shaft and arms causes the guide roller to remain above the area of the chassis 1 bounded by the guides 25 and 26.

That is, in the preferred embodiment, the axis of the guide roller 21 remains directly above the longitudinal centre line of the chassis. In the preferred embodiment the high level rails would also be equally disposed about a vertical plane passing through the longitudinal centre line of the chassis. In this case the mast would be constrained to remain in a vertical orientation whatever position it may take up relative to the chassis over the working range of the mast traverse movement.

In a preferred embodiment there would be two mast guiding assemblies, one on each side of the mast. The second assembly is shown at 27, which number it should be understood, applies to the whole assembly and not the single item to which the number is linked.

It should be understood that the means for constraining the end of the control arm 22 remote from the vertical shaft 17 need not be of the same form or construction as that for the guiding means attached to the end of the guide arm 19 remote from the vertical shaft 17.

The constraint for the control arm 22 could, for example, take the form of a pivoting block sliding between the rails, or guide bars 25 and 26.

In a further embodiment the control arm 22 could, for example, be pivotally connected to one end of a link 28 (shown in dashed outline). The other end of the link would be pivotally connected to the chassis 1 at 29.

Claims (8)

1 Equipment for stabilising and guiding the masts of vehicles used for mechanical handling and other purposes comprising a number of guiding elements attached to the mast of the said vehicle said guiding elements co-operate with rails or similar features attached to the storage racks or to other structures or to the associated building wherein said guiding elements are so mounted upon the said mast that relative movement between the guiding elements and the mast is possible.

2 Equipment as claimed in CLAIM 1 wherein the relative movement between the guiding elements and the mast is controlled in such a manner as to ensure any movement of the mast relative to the chassis or body of said vehicle causes an opposed movement of the guiding elements relative to the mast which causes the relative position between the guiding elements and the chassis or body of the vehicle to remain fixed or substantially fixed.

3 Equipment as claimed in CLAIM 2 wherein the mast is slideably connected to the chassis or body of the vehicle.

4 Equipment as claimed in CLAIM 3 wherein the said guiding elements are disposed in a symmetrical or substantially symmetrical arrangement about the mast.

5 Equipment as claimed in either CLAIM 3 or CLAIM 4 wherein the device or devices which cause the relative movement between the guiding elements and the mast comprise a guide or guides attached to the chassis or body said guides constrain guiding means attached to the sub-assembly supporting the said guiding elements.

6 Equipment as claimed in either CLAIM 3 or CLAIM 4 wherein the device or devices which cause the relative movement between the guiding elements and the mast comprise an arm or arms pivotally attached to the chassis or body said arm or arms are in turn pivotall attached to the sub-assembly supporting the said guiding elements.

7 Equipment as claimed in any of the foregoing CLAIMS wherein the parts are so proportioned and arranged that when the said mast is driven across the chassis or body a defined inclination can be imparted to the mast.

8 Equipment substantially as described by way of example and shown in FIGURE 1.