GB1595995A

GB1595995A - Mobile ladder unit

Info

Publication number: GB1595995A
Application number: GB557778A
Authority: GB
Original assignee: INTEGRATED HANDLING SOUTHERN L
Current assignee: INTEGRATED HANDLING SOUTHERN L
Priority date: 1978-02-11
Filing date: 1978-02-11
Publication date: 1981-08-19

Description

(54) MOBILE LADDER UNIT (71) We, INTEGRATED HANDLING (SOUTHERN) LIMITED, a British Company, of 77 Milford Road. Reading, Berkshire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:-- This invention is concerned with improvements in or relating to a mobile ladder unit for use with equipment for handling goods and sundry other articles.

In a large warehouse, storage of goods is often on shelving extending along aisles of considerable length and to a height greater than that which can be comfortably reached unaided from ground level. To assist removal of goods from the shelving, and also restocking of the shelves, it is common to use mobile step ladder units which can be pushed up and down the aisles to any desired location to gain access to shelves at high levels. Where a range of goods is to be removed from the shelves, necessitating a collector gathering a number of articles together. trolleys providing containers are moved up and down the aisles and the goods or articles collected are deposited therein according to a manifest carried by the collector.Therefore. when a number of goods has to be gathered from upper shelving levels. a collector has to manipulate both a trolley and a ladder unit which in the confined space of an aisle can be cumbersome and awkwanl especially when both units are usually mounted on castors. A further disadvantage lies in that where a number of people are working in a warehouse. there is a tendency for each person to use the most adjacent ladder unit. thereby inconveniencing another person who may have temporarily ieft tlhai ladder unit while collecting goods from low readily-accessible shelves.

These problems become more prevalent in warehouses or stockrooms of shops where the trolleys and ladder !nits are usually manipulated by female personnel who are required to collect items. e.g. of clothing. from shelving such as described above. convey the trolley, when their manifest is complete, to a checking point, transfer the goods as they are checked from the trolley to a second trolley which is then taken out onto the shop floor for transfer of the goods to sales counters.

The present invention provides a mobile step ladder unit comprising a base, a set of steps mounted on the base, ground engaging wheels comprising at one end portion of the base of the unit a set of wheels mounted for rotation about a fixed horizontal axis and at the opposite end portion of the base of the unit a wheel or wheels which can swivel each about a respective vertical axis, said one end portion of the base being shaped in plan view to have projecting and recessed portions to fit a complementarily shaped end portion of a trolley for use with the unit, the set of wheels mounted for rotation about a fixed axis being mounted on said projecting portion(s) whereby said axis extends across said recessed portion(s) and said axis being sufficiently spaced from the base of the recessed portion(s) that wheels of a similar diameter mounted on the projecting part(s) of a said trolley will lie on the said axis when the said part(s) are engaged in the recessed portion(s) of the step ladder unit.

Preferably the wheel or wheels provided at said opposite end of the unit is/are mounted on a spring-loaded arrangement and the unit includes a foot whereby under the weight of a user, the unit is lowered so that the foot engages the ground to prevent inadvertent movement of the unit.

Preferably said means comprises a latch arranged to engage a detent on the trolley and means whereby the latch can be disengaged from the detent.

A ladder unit according to the present invention is intended for use with a trolley as disclosed and claimed in the complete specification of our copending U.K. patent application No. 21181/79 (Serial No 1595692).

This trolley is intended for carrying articles and comprises a base and a plurality of ground engaging wheels on which the base is mounted the wheels comprising a set mounted for rotation about a fixed horizontal axis at one end portion of the trolley and a wheel or wheels at the opposite end portion of the trolley which can swivel each about a respective vertical axis, the said one end portion of the base being shaped in plan view to have projecting and recessed portions to fit a complementarily shaped end portion of a mobile step ladder unit for use with the trolley, the set of wheels mounted for rotation about a fixed axis being mounted on said projecting portion(s) whereby said axis extends across said recessed portion(s) and said axis being sufficiently spaced from the base of the recessed portion(s) so that wheels of a similar diameter mounted on the projecting part(s) of a step ladder unit will lie on the said axis when the said part(s) are engaged in the recessed portion(s) of the trolley.

The arrangement of the sets of wheels of the trolley and of the ladder unit is such that the fixed horizontal axes thereof coincide.

When the ladder unit and trolley are secured together, the alignment of the fixed sets of wheels allows the combination to be pivoted easily and when the requirement for the ladder unit is complete once the trolley has been loaded, it can be readily detached and the trolley taken to an unloading location e.g., a shop floor. It will also be appreciated that the invention is also readily applicable for use in libraries or any other facility where access to storage shelving is necessary.

There now follows a detailed description which is to be read with reference to the accompanying drawings of a mobile stepladder unit according to the invention in combination with a trolley as disclosed in the aforesaid complete specification; it is to clearly understood that this ladder unit has been selected for description to illustrate the invention by way of example.

In the accompanying drawings: Figure l is a side view of a combination of a step-ladder unit according to the invention and a trolley; Figure 2 is a plan view of the bases of the step-ladder unit and trolley shown in Figure 1: Figure 3 is an end view of the trolley shown in Figure 1; Figure 4 is a fragmentary view of an upright of the trolley shown in Figure l; Figure 5 is a detailed plan view of a detail of abutting end portions of the ladder unit and the trolley shown in Figure 1; and Figure 6 is a detailed view of part of means releasably securing the ladder unit to the trolley.

The mobile step-ladder unit and trolley combination illustrated in the drawings is intended for use in a stockroom or warehouse associated with a department store or shop. The ladder unit is indicated by the general reference 10 and the trolley by the general reference 12.

The ladder unit comprises a base 14 of substantially rectangular shape on which is mounted a set of five steps 16, with non-slip treads, having side hand-rails 18 of tubular metal. The uppermost step provides a plaS form of greater area than the other four steps.

The base 14 of the ladder unit is mounted on ground-engaging wheels comprising a set of two wheels 20 which are independently mounted for rotation about a fixed transverse horizontal axis, indicated in chain-dot line at 22 in Figure 2, at one end of the base and two independently mounted spring-loaded wheels 24 which provide castors. The castors 24 are spring-loaded so that under the weight of a user, a foot 26 provided by an extension of each hand-rail 18 can engage the floor and prevent undesired movement of the unit. The one end of the base of the unit whereat the wheels 20 are mounted is shaped to provide a recess 28 which is of trapezoidal shape when viewed in plan for the purpose hereinafter described.

The trolley 12 comprises a base 30 of substantially rectangular shape having upright corner posts 32 between which side walls 34 and end walls 36 of the trolley extend. The base 30 is mounted on groundengaging wheels comprising a set of two wheels 38 which are mounted for rotation about a fixed transverse horizontal axis beneath a trapezoidally-shaped end portion 40 of the base 30. The portion 40 is of a shape and size such that it can abut snugly within the recess 28, and the fixed axis is so positioned that when the mobile ladder unit 10 and the trolley 12 are brought into abutting relationship, the axis is in line with the axis 22. At the opposite end of the trolley, the base is supported by swivellably mounted wheels 42.

The side walls 34 are made of wire mesh 44 and one of the end walls 36 i.e. that on the extreme right of Figure 1 may also be made of wire mesh. However, the opposite end wall of the trolley, and the right-hand end wall, may be of collapsible construction so that access can be gained to goods deposited in the trolley. One form of collapsible wall is illustrated in Figure 3 wherein the wall 36 is provided by sheet-form plastics material having transverse rigid rods 45 attached thereto, the end portions of the rods being slideably guided in slots 46 formed in the upright corner posts 32 which may be of square or circular sectioned tubular metal.

The slots 46 may have recesses 48 into which the top rod can be dropped if it is only required to reduce the overall height of the wall by a fixed amount. (As an alternative, the top rod 44 may be hooked at each end so that the hooks can simply sit in the open tops of the corner posts, and brackets may be provided on the corner posts to hold the rod at fixed heights. In terms of manufacturing costs, this would be advantageous as it would be unnecessary to form the slots in the corner posts).

Reference is now made to Figures 5 and 6 which show, in detail, the inter-relationship of the ends of the trolley and the ladder unit.

Figure 5 shows the closeness of the fit between the recess of the base of the ladder unit and the end portion of the trolley. The means for releasably securing the ladder unit and the trolley comprises a spring-loaded latch member 50 mounted on a vertical pivot 52 and having a tongue portion 54. The latch member 50 is mounted in the base of the ladder unit adjacent one side of the recess 28 in a position such that the tongue portion 54 can project under the influence of a tension spring 56 through a slot 58 in the side of the recess and engage an edge of a corresponding slot 60 formed in the side of the end portion 40 of the base 30 of the trolley when the end portion 40 is engaged properly in the recess 28, to prevent the ladder unit 10 and the trolley from separating.To facilitate engagement of the latch member 50 in the slot 60, the latch member is formed with a cam surface 62. In order to release the latch member from the slot 60, a cable 64 leads from the latch member 50 via guides (not shown) to a lever or handle arrangement (not shown) mounted at a convenient location on the hand rails 18 of the ladder unit. Although only one latch arrangement is shown, two such arrangements are provided one at each side of the recess 28.

The shaping of the ends of the ladder unit 10 and trolley 12 can be reversed with the recess provided in the end of the trolley and, if desired, both ends of the trolley can be shaped so that the ladder unit can be engaged at either end thereof.

WHAT WE CLAIM IS: 1. A mobile step ladder unit comprising a base a set of steps mounted on the base, ground engaging wheels comprising at one end portion of the base of the unit a set of wheels mounted for rotation about a fixed horizontal axis and at the opposite end portion of the base of the unit a wheel or wheels which can swivel each about a respective vertical axis. said one end portion of the base being shaped in plan view to have projecting and recessed portions to fit a complementarily shaped end portion of a trolley for use with the unit' the set of wheels mounted for rotation about a fixed axis being mounted on said projecting portion(s) whereby said axis extends across said recessed portion(s) and said axis being suffici gently spaced from the base of the recessed portion(s) that wheels of a similar diameter mounted on the projecting part(s) of a said trolley will lie on the said axis when the said part(s) are engaged in the recessed portion(s) of the step ladder unit.

2. A mobile step ladder unit according to claim 1, wherein the wheel or wheels provided at said opposite end of the unit is/are mounted on a spring-loaded arrangement and the unit includes a foot whereby under the weight of the user the unit will be lowered so that the foot engages the ground to prevent inadvertent movement of the unit.

3. A mobile step ladder unit substantially as herein described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

costs, this would be advantageous as it would be unnecessary to form the slots in the corner posts).

Reference is now made to Figures 5 and 6 which show, in detail, the inter-relationship of the ends of the trolley and the ladder unit.

Figure 5 shows the closeness of the fit between the recess of the base of the ladder unit and the end portion of the trolley. The means for releasably securing the ladder unit and the trolley comprises a spring-loaded latch member 50 mounted on a vertical pivot 52 and having a tongue portion 54. The latch member 50 is mounted in the base of the ladder unit adjacent one side of the recess 28 in a position such that the tongue portion 54 can project under the influence of a tension spring 56 through a slot 58 in the side of the recess and engage an edge of a corresponding slot 60 formed in the side of the end portion 40 of the base 30 of the trolley when the end portion 40 is engaged properly in the recess 28, to prevent the ladder unit 10 and the trolley from separating.To facilitate engagement of the latch member 50 in the slot 60, the latch member is formed with a cam surface 62. In order to release the latch member from the slot 60, a cable 64 leads from the latch member 50 via guides (not shown) to a lever or handle arrangement (not shown) mounted at a convenient location on the hand rails 18 of the ladder unit. Although only one latch arrangement is shown, two such arrangements are provided one at each side of the recess 28.

The shaping of the ends of the ladder unit

10 and trolley 12 can be reversed with the recess provided in the end of the trolley and, if desired, both ends of the trolley can be shaped so that the ladder unit can be engaged at either end thereof.

WHAT WE CLAIM IS: 1. A mobile step ladder unit comprising a base a set of steps mounted on the base, ground engaging wheels comprising at one end portion of the base of the unit a set of wheels mounted for rotation about a fixed horizontal axis and at the opposite end portion of the base of the unit a wheel or wheels which can swivel each about a respective vertical axis. said one end portion of the base being shaped in plan view to have projecting and recessed portions to fit a complementarily shaped end portion of a trolley for use with the unit' the set of wheels mounted for rotation about a fixed axis being mounted on said projecting portion(s) whereby said axis extends across said recessed portion(s) and said axis being suffici gently spaced from the base of the recessed portion(s) that wheels of a similar diameter mounted on the projecting part(s) of a said trolley will lie on the said axis when the said part(s) are engaged in the recessed portion(s) of the step ladder unit.
2. A mobile step ladder unit according to claim 1, wherein the wheel or wheels provided at said opposite end of the unit is/are mounted on a spring-loaded arrangement and the unit includes a foot whereby under the weight of the user the unit will be lowered so that the foot engages the ground to prevent inadvertent movement of the unit.
3. A mobile step ladder unit substantially as herein described with reference to the accompanying drawings.