GB2532423A - A cantilever mounted access device - Google Patents

A cantilever mounted access device Download PDF

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Publication number
GB2532423A
GB2532423A GB201420406A GB201420406A GB2532423A GB 2532423 A GB2532423 A GB 2532423A GB 201420406 A GB201420406 A GB 201420406A GB 201420406 A GB201420406 A GB 201420406A GB 2532423 A GB2532423 A GB 2532423A
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GB
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Patent type
Prior art keywords
access
structure
ladder
access device
mounting
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB201420406A
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GB201420406D0 (en )
Inventor
Andrew Beard Michael
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Andrew Beard Michael
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Classifications

    • EFIXED CONSTRUCTIONS
    • E06DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06CLADDERS
    • E06C1/00Ladders in general
    • E06C1/02Ladders in general with rigid longitudinal member or members
    • E06C1/34Ladders attached to structures, such as windows, cornices, poles, or the like
    • EFIXED CONSTRUCTIONS
    • E04BUILDING
    • E04FFINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
    • E04F11/00Stairways, ramps, or like structures; Balustrades; Handrails
    • E04F11/02Stairways; Layouts thereof
    • E04F11/04Movable stairways, e.g. of loft ladders which may or may not be concealable or extensible
    • E04F11/06Movable stairways, e.g. of loft ladders which may or may not be concealable or extensible collapsible, e.g. folding, telescopic
    • E04F11/068Movable stairways, e.g. of loft ladders which may or may not be concealable or extensible collapsible, e.g. folding, telescopic telescopic
    • EFIXED CONSTRUCTIONS
    • E06DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06CLADDERS
    • E06C1/00Ladders in general
    • E06C1/02Ladders in general with rigid longitudinal member or members
    • E06C1/04Ladders for resting against objects, e.g. walls poles, trees
    • E06C1/08Ladders for resting against objects, e.g. walls poles, trees multi-part
    • E06C1/12Ladders for resting against objects, e.g. walls poles, trees multi-part extensible, e.g. telescopic
    • EFIXED CONSTRUCTIONS
    • E06DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06CLADDERS
    • E06C1/00Ladders in general
    • E06C1/02Ladders in general with rigid longitudinal member or members
    • E06C1/04Ladders for resting against objects, e.g. walls poles, trees
    • E06C1/08Ladders for resting against objects, e.g. walls poles, trees multi-part
    • E06C1/12Ladders for resting against objects, e.g. walls poles, trees multi-part extensible, e.g. telescopic
    • E06C1/125Ladders for resting against objects, e.g. walls poles, trees multi-part extensible, e.g. telescopic with tubular longitudinal members nested within each other
    • EFIXED CONSTRUCTIONS
    • E06DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06CLADDERS
    • E06C9/00Ladders characterised by being permanently attached to fixed structures, e.g. fire escapes
    • EFIXED CONSTRUCTIONS
    • E06DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06CLADDERS
    • E06C9/00Ladders characterised by being permanently attached to fixed structures, e.g. fire escapes
    • E06C9/06Ladders characterised by being permanently attached to fixed structures, e.g. fire escapes movably mounted
    • E06C9/08Ladders characterised by being permanently attached to fixed structures, e.g. fire escapes movably mounted with rigid longitudinal members

Abstract

A cantilever mounted attic ladder comprises, a series of nested ladder sections that slide and extend from a collapsed position to an extended, in use position, see figure 7. To deploy the ladder a strap 8 is pulled to overcome the bias of over centre springs 18 that act to hold the ladder within the loft access. The ladder is released by actuation of a pair of catches 39 that allow each section to extend in turn with respect to the next section. The sections are profiled and engage with one another. The sections widen towards the bottom of the ladder to promote stability. The ladder, the pivoting means and springs may be releasably located within a mounting bracket 10 that is affixed to the loft hatch sides via screws 11. In alternative embodiments adjustable brackets may be supplied and adjustable stops may be provided to adjust the final position of the ladder within the loft hatch, see figure 22.

Description

Title: A cantilever mounted access device

Background to the invention

There are many types of access devices including ladders used to gain access to lofts, and elevated and remote locations. The majority are bulky, consuming otherwise useful space when fitted and stored in the loft, they are complex and difficult to install and often difficult and often dangerous to use. Some modern ladder types are more compact using telescopic and concertina configurations and these are generally easier to install, easier and safer to use and take up less space.

A most effective ladder used for gaining access to a loft or from one place to another is one that can be located wholly within the access aperture or loft door hatch so taking up none or any useful floor or space. Location totally within the access aperture or door hatch also enables good access to the ladder from either side to release, lower and extend the ladder below or above that aperture.

A compact nested ladder used for this purpose has many other benefits. The smaller are the elevation and plan profiles and volume of the retracted ladder assembly the more loft access apertures and door hatches it can be fitted to without modification. The smaller, simpler, and lighter is the closed retracted ladder assembly and mounting the easier it is to fit and use.

Other features such as spring biasing, low operational loads, safe lowering and extension of the ladder and safe closing and retracting of the ladder add to the benefits the ladder can offer the user and installer.

While some ladders already provide solutions for the installer and user there is still much opportunity for improvement. Further reducing the size, weight and bulk of the closed retracted ladder, making the ladder easier and faster to open and close, and making the ladder easier, quicker and safer to install are features and benefits of this invention, a compact, quick to fit and quick to release, cantilevered mounted, self-supporting access device.

There are various types of compact telescopic or multi-section extending ladders that are suited to being adapted for use as a ladder for accessing lofts or attics. Many of the existing designs have substantial supporting frames, structures and mechanisms to allow the ladder to be fixed and supported near to the loft access aperture. Their bulk and complexity make them difficult to install and use, and take up unnecessary space in the access aperture and space above and around the access aperture.

This invention a cantilever supported access device with an extending and retracting access structure and cantilevered supporting means enables a very compact arrangement for the access structure and mounting apparatus, the ladder supporting means and installation means such that it can be fixed within and be stored wholly within the access aperture or above and within the door profile. Doors can be fitted to both sides of the ladder without any impact on its function.

Description of one embodiment of the invention

This invention provides a means, an access structure such as a ladder, stairs or steps, to gain access from one place to another, that is retained, as a cantilever supported retracted compact assembly, to one or more sides of an access aperture and wholly located within the aperture, so consuming little or no space outside of such aperture and so retaining full use of the space above and below which the access aperture is located.

A typical application, but not limited to such, is a ladder to gain access to or from a loft or attic in a house. In existing examples of loft ladders the ladder and attachments are located in part or whole outside of the aperture so consuming useful space, creating obstacles and restrictions to access, and they are often larger than the access aperture requiring enlargement of the apertures and the ladders are often complex to fit and use.

In one embodiment of the invention there is a telescopic ladder which is attached within and on one side the access aperture by means of spring biased pivots as a cantilever supported extendable and retractable access structure with the pivotal part of the spring biased pivot attached to the ends or sides of the stiles, rungs or structural members of the uppermost first fixed non sliding element of the ladder or steps and the fixed part of the spring biased pivot being attached to one or more sides of the access aperture by mounting apparatus. In other configurations of the invention the fixed part of the spring biased pivots are retained to more than one side of the access aperture using a plurality of detachably attached mounting means that enables a more versatile, easier, safer and quicker way of installing and adjusting the access structure within the aperture.

So in an example of this invention a loft ladder, the access device comprises, the ladder assembly, a mounting plate with detachably attached hooking elements, cantilever supporting spring biased pivots with devices to locate securely in the hooking means, spring bias means, and a retaining means to secure and release the retracted ladder and then lower the ladder to its operational position before it is then fully extended.

Describing the installation of one embodiment of the access device in the access aperture demonstrates the construction and function of the assembly, subassemblies and key component parts.

Firstly a mounting plate, typically but not exclusively a single plate extending across part or the whole of the width of the ladder assembly, is independently fixed, typically mounted centrally, on to one side of the access aperture to the loft. The position of the mounting plate is such as to allow a door to be independently fitted and closed below the ladder assembly.

With the mounting plate fixed to the access aperture the ladder and spring biased pivot assembly is then located and secured on to detachably attached hooking or retaining features on the mounting plate, then adjusted, locating the assembly in its stored location as an extendable and retractable ladder ready to provide access to and from such place as a loft. It is advantageous to incorporate a safety device to avoid accidental displacement of the access structure and supporting means from the fixed part of the detachably attached mounting.

It is a notable feature of this invention that when fitting the ladder assembly to the aperture it is beneficial the installer does not have to handle the entire weight of the ladder and mounting assembly when aligning and fastening the ladder to the access aperture. With the detachably attached mounting arrangement the installer has only to handle the weight of the mounting plate, circa 1kg, during the alignment and attachment to the access aperture rather than the entire weight of the ladder assembly, circa 12kg. Consequently it is much easier and safer, at this critical point of the installation, to position, align and secure the mounting for reliable and safe use of the installed loft ladder.

The detachably attached mounting arrangement and use of independently fitted mounting plates enables the rapid mounting and also dismounting of the ladder assembly should greater access be required through the aperture or the ladder removed for maintenance.

The ladder assembly typically has two spring biased pivots fixed to either side of the fixed first element of the ladder locating onto two matched hooking features on the mounting plate. The static fixed part of the spring biased pivots are mounted to the hooking features using such as a bar or tube but not limited to such. These fixed static pivot parts when attached and secured to the mounting plate embody other functions such as means to adjust the height and angle of the ladder assembly in the aperture and when extended.

The pivotal part of the spring biased pivots are attached to the uppermost cantilever supported element of the telescopic ladder or extendable ladder such that the entire ladder is cantilevered through the spring biased pivots, the fixed and pivotal hinge elements being spring biased such that the closed retracted ladder assembly is held, in this instance, in a nominally horizontal cantilevered orientation by the spring bias force on each pivot against a stop which may be adjustable.

The pivots and mounting apparatus can also embody features for adjusting the ladder height, ladder angle and the hinge angle. The spring bias may be fixed or variable and provide other functions such as indexing, resistance to rotation and supporting means.

On some configurations of the invention the springs fitted to the pivots are offset from the neutral axis and apply a torsional load along the pivot axis so it advantageous to fit restraining devices between the fixed and moving parts of the pivot assembly to reduce distortion and eliminate catastrophic failure.

The ladder and supporting pivot assemblies can be connected and removed as one entity from the hooks on the mounting plate without displacing or extending the springs so eliminating the danger of the installer being obliged to fitting these very strong springs as is the case on many other loft ladder assemblies in the market.

In other embodiments of the invention the detachably attached connection or mounting can be between the pivot assembly and the upper most or fist element of the ladder such that the ladder can be easily removed and the mounting and pivoting means retained in the access aperture.

The geometry and mechanical loading on the pivots is such that with the ladder in the closed position the pivot can be located to reduce the spring bias required and to allow the spring axis to go over centre of the pivot axis such that once the ladder assembly is lowered from the stored position in the loft access aperture and the spring passes "over centre" the pivots open typically toward and on to a fixed or adjustable stop defining the working position of the ladder.

Other configurations of the spring bias pivotal cantilevered mounting can be used to locate, and control the ladder to and from the stored location and in designated working positions. For instance cams about the pivot axis with indents in to which rollers or stops are spring biased can be embodied in the pivot assemblies to hold the ladder against its own weight in any designated position or provide controlled resistance or assistance to rotation.

Any type of retractable nested access structure can be fixed into the access aperture using the spring biased cantilever pivots and detachably attached mounting apparatus but the preferred ladder type is the telescopic or extending ladder where the stiles are of identical or similar profile, interlocked, offset and adjacent to one another and the ladder assembly arranged with width reducing from bottom sliding element to the top fixed element.

This arrangement is beneficial as it is a more stable ladder to use but significantly in the nested fully retracted configuration the closed assembly when viewed from the principal elevation creates two triangular voids within its rectilinear volume and profile of the closed ladder assembly. These voids can be of sufficient volume and useful geometry as to enable the ladder, cantilever supporting pivots and mounting apparatus to be located.

So this configuration of the invention is notable in that it is possible to arrange all the functional parts of the ladder assembly, the supporting spring biased cantilevered pivot mounting arrangement within the three rectilinear Cartesian coordinates of the ladder assembly making it notably compact and enabling it to be fitted to even smaller loft access apertures.

Other retractable multiple section ladders, such as tubular telescopic, concertina, overlapping sections, can be arranged to use this spring biased cantilevered supporting and operating mechanism.

A preferred ladder for this invention is one with offset stiles, duplex sliding bearings, automatically engaging spring biased locking means to lock each sliding section as the ladder is fully extended, and retaining means to secure all the sliding ladders sections together as one unitary retracted and restrained assembly. The ladder assembly can also be constructed with no intermediary bearings between sliding elements.

In other forms of the invention the cantilever supporting pivoting means can extend beyond the Cartesian coordinate boundaries of the ladder.

The sliding ladder elements can be fitted with no intermediary bearing means the elements just sliding against each other with material to material contact. Plain sliding bearings of suitable material can arranged between the sliding sections. Duplex sliding bearings are preferred as they enable low friction sliding and the full transmission of torsional and bearing loads from sliding element to sliding element without damaging the sliding bearings.

The locks or latches can be so configured that the ladder can be arranged to extend or retract from the bottom element upwards or the top element down.

In one simple form of this invention the access structure is restrained in the nested format by means of a rigid or elastic strap and fasteners, the strap being continued to form and provide a means to pull the ladder down from the loft access aperture and then released to extend the ladder. In this format it is not essential to use locking or latching means to secure adjacent sliding elements of the ladder in the nested retracted configuration. The elasticity of the strap or the strap mounting enables the spring bias to retain the ladder assembly as a compact nested assembly.

As an alternative to a flexible or extendable strap, a rigid or semi rigid closure may be used to retain the sliding elements in the nested retracted ladder format and also provide a means to lower the ladder assembly from the loft access aperture.

In a preferred embodiment of the invention the retention means for the retracted access structure comprises: a non-extendable strap, a locking plate, a spring biased detachably attached locking means with one end of the strap fixed to the first or uppermost sliding element and the spring biased locking means on the outer most or bottom sliding element on the access structure. A locking plate is attached to the strap in a position that when the locking plate is inserted and retained in the spring biased locking means the retracted access structure is restrained from opening or extending. The strap continues beyond the locking plate and locking means to provide means to lower the retracted access structure against the spring bias of the supporting structure.

A notable safety feature of this retaining means is the need to simultaneously unlock two independent locking elements in a spring biased locking means to release the locking plate and strap so allowing extension of the access structure. The release points for the two locking elements are typically located at either side and base of the outer most or bottom sliding element such that the operator has to place one hand either side on the base of the access structure so supporting the weight and preventing accidental extension of the access structure while the retaining means is released. In one embodiment the spring biased locking means, locking plate and strap are located centrally on a cross member conjoining the sides or stiles on the outermost sliding element and the release elements extended either side or the locking means to the each side of the outermost sliding section where they can be released by each thumb on each hand displacing each of the two locking elements.

Extension of ladder The access device, in this description, a ladder and supporting assembly can be fitted in a loft access aperture whether there is an existing door or access panel or not. With the ladder assembly and supporting means cantilevered horizontally from one side of the access aperture and the door lowered or removed the ladder can by holding the extended part of the strap be pulled down against the spring bias of the pivotal supporting means during which motion the spring bias is arranged to go "over centre", or from one indent to another, and the spring bias changes from spring biasing the assembly naturally up to now holding the ladder down in its working, usually a near vertical, position.

The ladder retaining device is then unfastened allowing the nested ladder to be fully extended each section automatically locking in pre-set positions to form a secure fully locked ladder. The ladder is concurrently or subsequently lowered to the floor ready to use.

Feet are located on the base section of the ladder to eliminate movement and damage to the floor. Alternatively compliant rollers or roller could be used as an alternative to static feet Release and stowage of ladder In one configuration of the cantilevered ladder assembly two safety catches located either side on the outside of each stile on the lowest sliding element must be displaced simultaneously to unlock the lowest ladder sliding element. Having depressed the two safety catches the lower sliding element is raised sliding eventually on to the next sliding element until the leading and upper edge of the stiles on the first moving element make contact with and depress cams on the stiles on the adjacent sliding element causing each to unlock whereupon the second sliding element can be freely raised and retracted along with the first sliding element. These then slide further on to the third sliding element causing this to automatically unlock, the process repeating until the user has unlocked, lifted and retracted all the sliding elements on to the cantilever supported fixed upper ladder element.

The nested retracted ladder assembly is then restrained by fixing the locking plate attached to the strap into the spring biased locking means on the outermost sliding element.

In alternative configurations of this invention each sliding element has a latch mechanism arranged such that when each element is fully retracted a latch or lock engages between each adjacent stiles. When then next sliding element is retracted the locks or latches engage in the adjacent sliding element so when fully retracted in the nested format the ladder is fully restrained by the interlocking locks or latches located between adjacent stiles.

The bottom sliding element is conjoined by a tube, plate or rigid member which maintains this sliding element as a geometrically correct, rigid, robust structure to resist lateral and rotational movement when the user opens and closes the ladder assembly. Feet or rollers can be attached to this member that can also be used to hold the nested ladder assembly and provide location for the detachably attached locking plate and locking means.

The ladder may incorporate a handrail on one or both sides of the ladder.

It is a notable feature of this invention that the ladder is not supported or held in a frame or carriage. The entire ladder is held, cantilever supported from one end, in the horizontal stored and near vertical working positions from the uppermost ladder element which is fixed to the moving and rotating part of the spring biased pivots. The nested assembly can be stored or located in a vertical orientation or any angle between vertical and horizontal.

The static parts of the spring biased pivots are fixed by any suitable device or fastener to the mounting surface of the loft access aperture, the other pivoting end to the top element of the ladder. The spring bias can be configured in many ways around a pivot or pivoting linkage.

In this instance the pivot has a spring such that in the horizontal format the springs create a holding torque transmitted to the top element of the ladder so that the full weight of the ladder is held by the spring force. As the ladder is lowered and the hinge rotates the spring axis passes over the centre line between the two anchorage points for the spring and the spring force then assists in keeping the ladder down in its lowered working position.

Other forms of spring biased hinge, linkage or mechanism can be used to hold the ladder in its cantilevered and working positions. Common to all these mechanisms is the ability to hold the ladder in a horizontally cantilevered stored position above the loft access door and also in the near vertical position when the ladder is ready to use, or any other preferred positions. The geometry, nature and spring bias of the pivot or linkage can be arranged to provide a number of alterative functions.

To provide the holding force for the cantilevered access structure in the horizontal stored position in the loft access aperture To reduce the force required to lower and return the access structure from the horizontal stored position to the near vertical working position.

To bias against the gravitational force due to the mass of the access structure and mountings as it is lowered and raised.

To reverse the load on the access structure so that during the rotation of the pivot or opening of the linkage the forces are changed from biasing the access structure upwards to spring biasing the access structure downward.

To create fixed positions where the access structure can be located and parked.

By changing the geometry of the linkage or cams and the spring bias on the rotating pivot vary loads holding or driving the cantilevered access structure.

The pivot, linkage or mechanisms can have features to create end stops for the ladder in the stored and working positions for the ladder assemble and at any points between. These may be preferably but not exclusively adjustable. These can be used to adjust the orientation or position of the access structure. The spring bias can be configured to be adjustable.

The non-rotating fixed parts of the cantilevered spring biased pivot, linkage or mechanism can be fixed directly to the mounting surface in the loft access aperture. However in a preferred configuration of the invention it is advantageous to have a means of detachably attached means of fitting the access structure rapidly, easily, accurately, safely and with less effort into the loft access aperture.

A mounting plate with hooking or retaining means is so arranged that can be fixed independently to the nominally vertical surface of the loft access aperture. A template or measurements can be provided to give the correct location for the mounting plate. The mounting plate is light and can be quickly and easily fixed without the encumbrance of the bulk and weight of the entire ladder assembly a significant problem when fitting other loft ladders.

With the mounting plate and detachably attached mountings anchored to the loft access aperture the access structure and cantilever supporting spring biased pivot assemblies are lowered on to the mounting or retaining means such that holding members locate securely and the weight of the ladder hold the ladder in the correct mounting position. With safety retention devices removed the access structure and cantilever supporting spring biased pivot assemblies can be easily removed for replacement, maintenance or increased access thorough the access aperture.

There is provision for safety fastening or retaining pins such that with the access structure and cantilevered supporting assembly are attached to the mounting plates, safety fastenings are secured and the access device cannot be removed or displaced accidentally.

There can also be provision, in or between the cantilevered mounting assemblies and the mounting plate for adjusting the height and angular position of the ladder assembly.

Access apertures are often of unknown mechanical and structural integrity and another embodiment of this invention is the use of a pair of mounting plates not only providing the attachment means for the spring biased cantilevered ladder assembly but also providing means to improve the structural load bearing of the access aperture and to better distribute the cantilevered loading created by overhanging mass of the entire ladder assembly. There are many alternative configurations but the following embodiment demonstrates all the intrinsic features offered by installing a pair of mounting plates.

In this example of an alternative mounting apparatus using matched pairs of mounting plates the fixed element of both pivots are conjoined by a single bar or structural member creating a common and unitary hooking or attachment means to the two independent mounting plates. Each mounting plate has a receiving means for the unitary bar or structural member and one or both can have an additional means to safely secure the hooking means onto both attachment means, one on each mounting plate.

In this example each mounting has two adjacent flat surfaces perpendicular to each other acting as one unitary structural element. Within pre-set maximum and minimum dimensions the plates are fixed in to adjacent corners either end of the mounting surface of the access aperture and horizontally aligned. Each plate has a hook or attachment means to receive the single bar or structural member conjoining the two hinges on the cantilevered ladder hinge assembly.

The arrangement of the single bar or structural member and receiving means is such that the plates can be in contact with each other at centre of the mounting surface of the access aperture or any distance apart up to the dimensional limits of the single bar or structural member.

The pair of mounting plates, flat or right angled can be fixed in wide range of access aperture widths.

Preferably the right angled plates nest into the corners at each end of the common mounting surface for the cantilevered ladder assembly. The two plane surfaces of each mounting plate have a plurality of holes to enable the mounting plate to be fixed both to the common surface and the adjacent surfaces or faces of the access aperture.

The mounting plates in this configuration provide improvements for retaining the ladder in the access aperture. Each right angle plate acts as robust structurally strengthening element at the two intersections of the access aperture. Secondly the turning moment imposed on the principal mounting surface of the access aperture by the cantilevered weight of the ladder and pivotal mounting assembly can be transferred partly or in whole to each adjacent side such that plate fixings take the forces of the turning moment on the fastening means in shear rather than axially on the common mounting surface. In shear the fastening is stronger and more reliable and more able to resist the turning moment than the axial loading of the fastenings in the common mounting surface. As such the integrity, reliability and safety for the ladder attachment is greatly improved.

The adjustment of the hooking means may also be achieved by having adjustable structural members extending and clamped on the outside of each pivotal assembly or hinge. There are many are such similar arrangements.

In other examples for mounting plates the plates may provide the means for other functions such as providing fixing, hinging and locking for a door. Auxiliary functions may be added such as door seals, lighting an Figures 1 to 24 illustrate one particular embodiment of a cantilevered spring biased pivotal supporting means for an extendable and retractable access device. Additionally the figures illustrate rapid attachment and adjustment means for such an access device and how the construction of the access device and supporting means enables the entire assembly to be mounted within the access aperture and structure through which access is achieved.

Figures 1 to 6 illustrate a preferred construction for the access device and mountings where the access device is an extendable and retractable ladder the construction of which enables all the supporting and spring biasing pivoting means to be configured and located within the three principal Cartesian coordinates of the access device itself. In such a configuration the aperture can be almost that of the dimensions of the access device allowing for a working clearance on the un-mounted surfaces.

Figure 1 shows the access device, a telescopic ladder, the cantilevered spring bias pivotal supporting means, the detachably attached mounting means, the adjustment means and the mounting means to the structure or surface to which the assembly is attached.

Figure 2 shows the access device mounted within the access aperture of a structure viewed from above the aperture.

Figure 3 shows the access device mounted within the access aperture of a structure viewed from below the aperture Figure 4 shows the access device mounted within the access aperture of a structure with the access device and mounting assembly lowered to an operating position and the access device, in this instance a ladder, still fully retracted and locked.

Figure 5 shows the access device mounted within an access aperture of a structure with the access device and mounting assembly lowered to an operating position, access device unlocked and partially extended Figures 6 and 7 show the access device mounted within the access aperture of a structure with the access device lowered to an operation position and fully extended Figures 8 and 9 show the attachment means, adjustment and retention of the access device and pivotal support Figure 10, 11, 12, 13 and 14 show details of the mounting, adjustment, pivoting and spring biasing means for the access device supporting assemblies and the means by which the ladder and spring biased pivotal supporting means is located, hooked onto the mounting or anchor plate and retained Figures 15 and 16 show details of the spring biased pivotal supporting means for the access device Figures 1, 2, 3 and 19, illustrate the compact arrangement of the access device and cantilevered supporting means an access aperture Figures 18, 19, and 20, illustrate a secure locking means for the retracted access device that requires two handed operation to unlock, release and extend the access device Fig 21 shows an alternative spring biased pivot and supporting means using a spring biased roller or stop and indents to position the access structure and variable circumferential profiles to provide resistance and assistance to motion.

Fig 22 shows a pair of mounting plates, 49, for the access device that also improve the mechanical and geometric integrity of the structure to which the access device is to be fixed by hooks, 48, and hooking means, 47.

In this particular embodiment of a cantilevered spring biased pivotally supported access device, the access device, 1, is a telescopic ladder, 2, where the stiles or slides, 6, are of identical or similar profile being interlocked and offset from each adjacent stile, 6, the extendable and retractable assembly being fixed at one end as a cantilevered structure to the spring biased pivotal supporting means, 18, these being located or hooked into an anchor or mounting plate assembly, 25, which is fixed to a structure, 20, or surface in an access aperture, 21.

In this example of the invention the access device, a telescopic ladder consists of a plurality or sliding elements, 33, each constructed from two stiles or slides, 6, connecting rungs, 5, with top caps, 31, bottom caps, 32, forming protective ends and sliding bearings. Within each sliding element is a spring biased locking pin that automatically engages in mating holes in the adjacent sliding element so automatically locking together adjacent elements as each is fully extended. On the outermost sliding element the stiles, 6, are connected by a member, 22, and feet, 3, so constructed and configured as to improve the rigidity of the bottom sliding element and telescopic ladder, 2.

As each sliding element, 33, is extended it automatically locks onto the adjacent element until the ladder is fully extended and locked ready to use.

To unlock and retract the ladder assembly first the release cams, 4, on either side of the lowest or outermost element must be simultaneously pushed to unlock this element, This the outermost element of the ladder is then retracted the action of which causes the top cap, 32, to engage and push the release cams, 4, so unlocking the next sliding element, 33, until the ladder is fully retracted The structural member, 22, provides attachment means for a catch, 7, connected to a strap, 8, one end of which is fixed to the rung, 5, on the uppermost ladder element attached to the supporting means, 18, the other end of which extends below the catch, 7, to enable the user of the access device to pull the entire assembly down from the spring biased location in the access aperture where it is stored. The strap, 8, with the catch, 7, engaged prevents the retracted or nested ladder assembly from opening as it pivots and lowers to an operational position.

In most configurations of the cantilever supported arrangement for the access device the supporting means, 18, is attached to the first or uppermost element on the access device. In this illustration of the invention the access device is a telescopic ladder with offset interlocking sliding stiles but any extendable and retractable access means can be attached to the supporting means such as or similar to the one described here. There are concentric tube telescopic ladders and concertina linkage ladders and others.

In this configuration of the invention the top or non-extending element of the ladder is fixed to the pivoting plates, 19, so the rest of the ladder is supported as a cantilevered structure or assembly from these plates, 19.

The cantilevered spring biased pivotal supporting means, 18, has two elements, the pivoting plate, 19 and the static plate, 26, which are connect by a pivot, 17, forming a rotational axis and bearing for the pivotal support.

On both the static plate, 26, and the pivoting plate, 19, there are mounting pins, 29 and 34, for the spring bias, 9, in this instance an extension spring. In the stored and retracted mode for the access device the hinge assembly has stops, 30, that hold the ladder nominally at 90 degrees to the mounting plates and surface. The spring is pre-tensioned to support the weight of the ladder and supporting assembly and as a safety feature two stops, 30, are used and each having retaining heads to prevent the pivoting plates, 19, bursting open should there be any failure of the assembly.

Stops, 27, bearing on surfaces, 28, prevent the over rotation of the pivoting plates, 19, and ladder, 2, without restricting the ladder being used in the statutory or recommended operational positions. The static plates, 26, have mirror imaged feature so they can by constructed to form left and right handed forms of the supporting means, 18.

The hole, 35, or this can alternatively be an open slot, provides retaining and securing means to fix the supporting means, 18, easily and rapidly to one or a pair of anchor or mounting plates, 10, that are previously attached to the access aperture surface, 21, or structure 20.

To install the access device, 1, to the surface of an access aperture, 21, or to a structure, 20, the anchor or mounting plate, 10, is first located and secured using a plurality of fixings, 11, the fixings being of any suitable type to provide secure anchorage.

In some instances where the structure, 20, or the aperture, 21, is structurally or geometrically inadequate a pair of mounting plates, 36, with two faces at 90 degrees each with receiving means, 12, for the supporting means, 18, can be used. The additional surface on each plate allows the plate to provide mechanical integrity and geometric alignment at the respective corners of the aperture and additionally allows the exclusive axially loads on the fixing screws as occurs on the single plate to be transferred partially or wholly to fixing along each side of the access device, 1, such that these side fixings take load in shear rather than axially. The integrity or the fasteners being more reliable.

With the mounting or anchor plate assembly, 25, attached to the surface or structure the access device assembly, 1, as a single unit can be hooked on to the plate by locating pins, 29, into the hooks, 12, then with the pins, 29 fully located rotating the access device assembly onto the threaded studs, 15, until the static plates, 26 rest on the adjuster nuts, 16. During this process the retaining or safety nuts, 14, are removed from the threaded studs, 15.

With the access device, 1, hooked and lowered onto the threaded studs, 15, the adjuster screws, 16 can be rotated to align the access device, 1, to the structure, 20, or mounting surface 21. Once the correct alignment is achieved the retaining or safety nuts, 14, are screwed on to the threaded studs, 16 and tightened. The access device, 1, is now secured onto the mounting or anchor plate, 10, and cannot be inadvertently removed or displaced from the hooks, 12.

It is a notable feature for this configuration of telescopic ladder, as illustrated in Figure 17 that the predominately triangular voids, A and B, within the three Cartesian coordinates of ladder volume provide working volumes into which the spring bias pivotal supporting means, 18, can be configured as matching pairs. Configured as such the access device can be located compactly in access apertures marginally greater than the size of the access device needing only a small allowance for operating clearances. This enables the fully benefits of using a compact telescopic ladder to be fully utilised in such applications.

Extending and retractable ladders suitable for these access devices often have primitive means such as fabric webbing and hook and tape fastening for retaining the nested or retracted ladder in the closed position. To provide an improved retaining means and to ensure the access device is correctly handled as it is lowered, unlocked and released to the operating position there is in this invention the provision of retaining strap, 7, and locking means, 38, and release means 29.

The strap, 7, is fastened to the upper most ladder element, 33. The strap, 7, extends along the back of the rungs, 5, on the retracted or nested sliding elements, 33, and coincident with the locking device, 38 on the bottom rail, 22, there is a locking plate, 40, fixed to the strap, 7, so as to prevent accidental opening of the nested ladder assembly. The strap, 7, continues beyond the locking plate, 40, to form a pulling means to lower the spring biased pivotal access device assembly.

The locking means, 38, is so constructed that pushing the locking plate, 40, into the locking device, 42, displaces the two spring biased release bars, 39, and which then locate into two recesses on the locking plate, 40. In this position the strap, 7, is locked in position and the retracted or nested ladder elements cannot extend.

To unlock and release the strap, 7, so as to extend the ladder, 23, both the release bars, 29, have to be disengaged simultaneously to release the locking plate, 40. This is a safety feature. The user of the access device lowers the assembly by pulling the end of the strap, 7, and the ladder remains secure in the nested format.

To release and extend the ladder the user is obliged to place one hand either side of the ladder on the bottom sliding element, and using fingers and thumbs pull the release bars, 39, outward against the spring bias so allowing the locking plate to disengage and the strap to fall away from the sliding ladder elements. With the users two hand so positioned the nested ladder is held correctly so allowing the ladder to then be lowered and full extended with one hand either side of the ladder.

An alternative spring biased cantilevered pivotal support for the access structure is shown in Figure 21 where spring bias, 43, is applied to a roller or stop, 44, that locates in indents, 46, in a circumferential arrangement providing location and support for the access structure. Profiles, 45, are also use to provide resistance and assistance to the rotation of the pivot and access structure it supports.

Claims (20)

  1. Claims 1) A cantilever mounted access device comprising; an extendable and retractable access structure, retaining means for the access structure, spring biased cantilever supporting pivots, and mounting apparatus in which the access structure has a plurality of extendable and retractable sliding elements, that when the elements are released from the retaining means and extended they automatically lock to the adjacent sliding element, and after the outermost sliding element is unlocked and retracted automatically unlocking the adjacent sliding element until all sliding elements are retracted, and the pivotal parts of the spring biased pivots are attached to the first element of the access structure, the other extending and retracting sliding elements of the access structure supported sequentially by the next sliding element from the further most extendable and retractable sliding element back to the first element, and a spring bias acting between the fixed part and the pivotal part of the spring biased pivot so that the access structure is supported from the first fixed element as a cantilevered structure and can be mounted and adjusted and held in any chosen position and the spring bias used in transition to resist or assist movement of the access structure.
  2. 2) An access device in Claim 1, where the access structure is; a ladder; steps; or stairs.
  3. 3) An access device as in Claims 1 and 2 where the retracted access structure is retained by a strap fixed to the sliding elements either end of the access structure and locked and released by means of detachably attached locking apparatus.
  4. 4) An access device as Claim 1 where the retaining device for the retracted access structure is released by simultaneously releasing two independent devices operated by each hand at or near to either side and base of the access structure and positioned such that the two hands support the weight of the access structure on the outer most or lowest sliding element allowing the user to extend the access structure while both hands support the weight of the access structure.
  5. 5) An access device as in Claim 1 where the spring bias of the retaining strap or the retaining strap mounting provides the retaining means for the detachably attached locking apparatus and retracted access structure.
  6. 6) An access device as in Claims Ito 4 where the retracted access structure is retained exclusively by the strap and retaining device.
  7. 7) An access device with detachably attached adjustable mounting apparatus, as in Claims 1 and 2, where a mounting plate or pair of mounting plates, each with a plurality of holes with which to fasten the plates to a structure, also function to improve the mechanical and geometrical integrity of the structure to which it is mounted.
  8. 8) Mounting apparatus, as in Claim 7, with detachably attached adjustable mounting where a mounting plate or pair of mounting plates each with a plurality of holes with which to fasten the plates to a structure have folded ends enabling the mounting plate or plates to be fastened to two adjacent surfaces of an access aperture or structure to further improve the mechanical and geometrical integrity of the structure to which it is mounted.
  9. 9) Mounting apparatus, as in Claims 1 and 2, where the mounting apparatus is detachably attached to the access structure and supporting means so enabling the retained mounting means, that has receiving means for the detachably attached access structure and supporting means, to be independently fixed to the holding surface or structure prior to the detachably attached access structure and supporting means being located into the receiving means and secured.
  10. 10) An access device with one or more spring biased pivots as in Claim 1 in which the over centre spring bias on the pivot is provided by the extension of a spring either side of the pivotal centre such that the access device is biased from an initial retained position through an over centre neutral position to another spring biased position where the access structure can be released, extended and used.
  11. 11) An access device and mounting apparatus, as in Claim 1 and 2, in which the spring bias and angular displacement of the access structure is provided by the spring bias on one or more rollers or stops onto indents, cams or features on a circumferential or defined profile about the axis of the spring biased pivot such that the access structure can be located in any stored position or operating position and a resistive or assistive spring bias applied during the transition to and from these positions.
  12. 12) A spring biased pivotal mounting means as in Claims 1, 2, 10 and 11, where the pivoting means is a linkage arrangement with a plurality of pivots.
  13. 13) An access device, as in Claims 1 and 2, where the cantilevered support for the first element of the access structure to a supporting structure or surface is in one predetermined position.
  14. 14) An access device, as in Claim 1 and 2, where the detachably attached mountings provide positional adjustment of the access structure.
  15. 15) An access device, as in Claim 1 and 2, that can be located within and mounted on one or more surfaces of the access aperture through which the access structure provides access.
  16. 16) An access device, in Claims 1 and 2, where the mounting apparatus, retracted access structure, and cantilever supporting spring biased pivoting means are configured within the principal three dimensional Cartesian coordinate boundaries of the access device enabling compact fitting into an aperture.
  17. 17) An access device in Claims 1 and 2, where the access structure comprises telescopic extendable sliding elements comprising identical or similar sliding profiles which are offset, adjacent and interlock to the sliding profiles in the adjacent sliding elements.
  18. 18) An access device, in Claims 1 and 2, where the access structure comprises telescopic extendable and retractable sliding elements that are concentric tubes of any profile with parallel sliding axes.
  19. 19) An access device, in Claims 1 and 2, which have extendable retractable elements that are of pivotal parallelogram construction.
  20. 20) An access device, as in Claims 1 and 2, where there is a detachably attached mounting between the first element of the access structure and the pivotal part on the cantilever supporting spring biased pivot.
GB201420406A 2014-11-18 2014-11-18 A cantilever mounted access device Withdrawn GB201420406D0 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB201420406A GB201420406D0 (en) 2014-11-18 2014-11-18 A cantilever mounted access device

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB201420406A GB201420406D0 (en) 2014-11-18 2014-11-18 A cantilever mounted access device
PCT/GB2015/053515 WO2016079516A1 (en) 2014-11-18 2015-11-18 Extendable access device
EP20150817491 EP3221545A1 (en) 2014-11-18 2015-11-18 Extendable access device

Publications (2)

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GB201420406D0 GB201420406D0 (en) 2014-12-31
GB2532423A true true GB2532423A (en) 2016-05-25

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2557286A (en) * 2016-12-05 2018-06-20 Vincent Cole Geoffrey A Ladder Apparatus

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2713113Y (en) * 2003-04-09 2005-07-27 松下电工株式会社 Ladder device
WO2005100716A1 (en) * 2004-04-16 2005-10-27 Telesteps Ab Loft ladder assembly
EP1777358A2 (en) * 2005-10-19 2007-04-25 Werner Co. Access ladder with plungers
US20120193167A1 (en) * 2011-01-28 2012-08-02 Appropriate Combined Technologies, Llc Telescoping pull-down attic ladder

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2713113Y (en) * 2003-04-09 2005-07-27 松下电工株式会社 Ladder device
WO2005100716A1 (en) * 2004-04-16 2005-10-27 Telesteps Ab Loft ladder assembly
EP1777358A2 (en) * 2005-10-19 2007-04-25 Werner Co. Access ladder with plungers
US20120193167A1 (en) * 2011-01-28 2012-08-02 Appropriate Combined Technologies, Llc Telescoping pull-down attic ladder

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2557286A (en) * 2016-12-05 2018-06-20 Vincent Cole Geoffrey A Ladder Apparatus

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