GB2414505A

GB2414505A - Combination loft ladder and lift

Info

Publication number: GB2414505A
Application number: GB0510662A
Authority: GB
Inventors: Daniel Harry Corby Quare
Original assignee: BU Innovations Ltd
Current assignee: BU Innovations Ltd
Priority date: 2004-05-28
Filing date: 2005-05-26
Publication date: 2005-11-30
Anticipated expiration: 2025-05-26
Also published as: GB0412007D0; GB0510662D0; GB2414505B

Abstract

Apparatus is provided for lifting a load 30 through a hatch 10 through a floor or ceiling. A ladder 12 is fitted to one side of said hatch and extendable through and below the hatch. A lift carriage 32 fits onto the ladder for movement upwards or downwards along the ladder. A hoist 38 is attachable to the lift carriage via cable 34 for raising or lowering thereof A frame 40, 42 for fitting to the floor or ceiling behind the hatch 10 has a movable portion 28 provided with a support for receiving the lift carriage on hoisting said lift carriage from said ladder through the hatch, The movable portion 28 is arranged on further hoisting of the lift carriage to pivot to from a lowered position where the support is in register with the top of the ladder to a raised position in which the lift carriage becomes located above and behind the hatch.

Description

24 1 4505 COMBINATION LOFT LADDER & LIFT

FIELD OF THE INVENTION

The present invention relates to a method of mechanically loading or unloading large or heavy items into an elevated space. The invention has particular application in connection with the mechanical loading of large or heavy items into a loft through an existing loft hatch, whilst still allowing access to the loft through the 0 same hatch by the user.

BACKGROUND TO TIlE INVENTION

The main problem with lifting the large or heavy items is that it has to be carried at the same time as the person doing the lifting is climbing up the loft ladder.

A separate pair of hands is required and at the same time as the goods are being lifted through the loft hatch, the person doing the lifting is also trying to get through the same aperture. Too many tasks need to be carried out by one person for the task to be achieved safely.

It is well know that the loading of large or heavy items into a loft space . manually can be a difficult and frequently dangerous task. Many domestic accidents : ,', are ladder related and causes include not setting ladders up properly, over stretching . . because the user cannot be bothered to adjust the ladder position, and using both hands to lift the boxes above a user's head when loading the lol't, leaving no hands . 'lo. free to hold the ladder. A separate lift can be installed in some instances but this is : usually prohibitive on the grounds of cost or through lack of available space and a separate point of entry to the loft is usually required.

US-A-2005/0067223 (Penn) discloses a platform lift system includes a mounting frame that is Goodly engaged into a hatch formed in a horizontal supporting surface (i.e. attic floor or room ceiling) and a foldable ladder that is supported by the mounting frame. The mounting frame is flush with the ceiling floor to maximize - 2 available storage space within the attic ceiling. The ladder is broken into sections that are folded upon one another within the mounting frame to provide a generally compact structure when stowed, and are hingedly attached to the frame. When in the deployed position, the ladder sections are extended in alignment with each other to s enable a user to access the attic space as with conventional attic access systems having a pull-down ladder. A separate trolley carries a lift platform that may be selectively raised or lowered in order to transport objects to/from the attic space. The trolley is moveable horizontally along a track that may be provided on a floor of the attic space. At a first end of travel of the trolley along the track, the trolley is lo disposed laterally alongside and vertically offset from the mounting frame so that the space above the mounting frame is unimpeded to permit a user to access the attic space using the deployed ladder. At a second end of travel of the trolley along the track, the trolley is aligned vertically with the mounting frame to permit use of the lift platform. The trolley further includes a drive system that controls the movement of a four lift tethers that are coupled to corners of the platform, which can be raised by withdrawing the lift tethers, and can be lowered by paying out the lift tethers. The ladder has a track that provides a guide for movement of a lift platform, and the lift platform has includes wheels at one end that run on the track. . <

5,,,,. 20 By way of background, US-A-5911287 (Campbell) discloses apparatus for lifting a load onto a roof of a building based on a sled that slideably contacts a ladder, and a lift cable by which the sled may be hoisted and lowered.

SUMMARY OF THE INVENTION

The invention provides apparatus tor lifting a load, comprising: a hatch for a floor or ceiling; a ladder fitted to one side of said hatch and extendable through and below the hatch; a lift carriage for fitting onto the ladder for movement upwards or downwards along the ladder; a hoist attachable to the lift carriage for raising or lowering thereof; and a frame for fitting to the floor or ceiling behind the hatch having a movable portion provided with a support for receiving the lift carriage on hoisting said lift carriage from said ladder through the hatch, said movable portion being arranged on s further hoisting of the lift carriage to pivot to from a lowered position where the support is in register with the top of the ladder to a raised position in which the lift carriage becomes located above and behind the hatch.

For use with the apparatus as aforesaid, it also provides a frame t'or fitting to a 0 floor or ceiling behind a hatch, said frame comprising: a fixed portion for attachment behind the hatch; a movable portion pivoted to the fixed portion and provided with a support for receiving the lift carriage from the ladder, said pivoting connection between the fixed and movable portions being such is that providing for movement between a lowered position where the support can register with the top of the ladder to a raised position in which the lift carriage . becomes located above and behind the hatch.

BRIEF DESCRIPTION OF THE DRAWINGS

:.: .. 20 :. How the invention may be put into effect will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig 1 is a diagrammatic view perspeclive of portions of a ceiling with a hatch formed therein, and lifting apparatus according to the invention fitted to the hatch; 2s Fig. 2 is a perspective view of a lift carriage and frame structure fonning part of the apparatus of Fig. 1, the lift carriage being shown as it enters a support forming part of the frame; Fig. 3 is a view similar to Fig. 2, but with the lift carriage having completed its movement into the support; Figs. 4 and 5 are views similar to Figs 2 and 3, but with a movable part of the frame structure partly raised and fully raised respectively; - 4 Fig. 6 is a section of a ladder forming part of the apparatus of Fig. 1; and Fig. 7 is a perspective view of the lift carriage.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

The present invention overcomes the problems of the prior art lift devices by providing a means of fitting both a powered lift and a ladder that can operate in the same space. The user first places the load to be lifted onto a platform. The platform is preferably then pulled parallel to the ladder, through the loft hatch via the use of a 0 cable. The cable passes over pulleys and is attached to a winch located in the loft space. The platform is then lifted clear of the hatch, enabling the operator to climb the ladder, pass through the hatch into the loft space and unload the platform. The operation can then be repeated as necessary or carried out in reverse to take loads sal'ely from the loft down to a lower floor level.

The lilt may be operated from either the lower floor level or from the upper : ,. floor/loft level or any other convenient position. The apparatus therefore has two

main "'unctions. Firstly it provides an easy method for accessing the loft via a set of . . . folding steps which when stowed away fold neatly in to the lot't. Secondly it allows :.: . 20 for single-handed loading and unloading of boxes and other articles into and out of :' the loft using a remotely controlled hoisting mechanism. The mechanism keeps the load placed on the platform completely stable and level throughout the entire lifting . process and can raise the load to a height within the loft that is easy to unload from without bending down thus preventing awkward bending to pick up an often heavy load...DTD: Preferably the loft loader is configured so that an electromechanical winch hoists a trolley with a horizontal platform mounted to it up inside channels on the front side of the ladder. When the trolley reaches the top of the ladder it rolls into another section of channel mounted on a pivoting frame that moves the platform level - 5 further away from the hatch keeping the load level so that there is still space for the user to climb the ladder into the loft and unload the platform.

In one preferred embodiment the way in which the trolley rolls into another s section of track is by using four wheels in line, on both sides of the trolley. When the first two wheels roll free from the channel on the front of the ladder, the remaining two keep the trolley level in the channel and moving in the same direction thus it rolls across the gap and into small length of channel (with end stops) mounted on the mechanism in the loft. lo

The mechanism in the loft uses a pivoting four sided frame acting as a flexible parallelogram to ensure the load remains level during the lifting process. When the trolley reaches the end stops in the channel the electro mechanical winch then hoists the trolley with attached platform using the pivoting parallelogram frame up and s across into the loft keeping it level. The user can then climb up the ladder and unload the platform which due to design of the parallelogram frame's design is at an ideal height for unloading without bending down. .

. . . . The use of a cut out mechanism in the winch motor ensures that the lift will . :.: . 20 not lift more than the design load. It will cut out should anything get trapped in the . mechanism thus minimising the risk of injury and damage to the motor. 'lithe hoisting mechanism will automatically shut off at both the bottom of the descent and the top of the ascent using proximity sensors. The person operating the lift can be made aware of this by the hand held control which will show an illuminated arrow in the 2s direction of the platforms movement which will cut out when the platform reaches then end of its ascent or descent.

The invention has also other applications apart from lifting loads into a loft. It can be used for moving loads up and down floors in workshops, factories and storerooms as well as in outside applications. - 6

ln Fig. 1, a hatch 10 in a ceiling has fitted thereto a folding ladder 12 formed of segments 14, 16 and 18 hinged together to form a straight continuous ladder as shown. The ladder segments may be folded up to overlie a trapdoor 24 hingedly connected to the hatch, the upper ladder segment 14 being attached to the trapdoor by brackets 20, 22. When folded away for storage the ladder rests neatly on top of the loft hatch and when un folded ready for use the position of the hinges means that the roller tracks all align so that the trolley can run up and down freely. A wheeled lift platform 32 that can carry a load 30 runs in tracks formed in the sides of the ladder and can be hoisted or lowered by pulling in or paying out a lift rope or cable 34.

ID Above the ladder and behind the hatch 10 there is fonmed a frame structure having a fixed portion 26 and a movable portion 28. 'I'he fixed portion comprises a horizontal frame 42 that fits to the ceiling behind the hatch, extending away from the ladder as shown, and a portal structure 40 at the back of the frame 42 and braced to the frame 42 by struts 41 (Fig. 2). A motor 38 located on or immediately above the frame 42 pays out or pulls in the rope or cable 34 via a pulley 36 on a cross-member forming part of the portal structure.

The movable part of the frame structure forms a pair of transversely spaced 4 bar parallelogram linkages comprising fixed rear members 44, 44a, front members 46, 46a, lower members 48, 48a and upper members 50, 50a, pivoted together as . . shown. The rear members 44, 44a are securely bolted to posts of the portal structure 40, and the two parallelogram linkages are held at the correct spacing by a spacer bar 54. A support 54 is fixed to the front members 46, 46a. It comprises a pair of side members whose shapes and spacing correspond to side members 12a, 12b of the ladder (Fig. 6) and which likewise have upstanding and in- turned flanges defining inwardly facing channels 56, and spacer members whose widths correspond to the ladder rungs. The lift carriage comprises a platoons 32a, sides 32b, 32c, a top spacer 32d and four rollers 58 spaced along and projecting outwardly from sides 32b, 32c.

When the lift carriage is on the ladder, the rollers 58 run in the side channels 56 and hold the carriage captive in the ladder. When the carriage 32 is lifted beyond the ladder, its rollers enter smoothly into corresponding channels 56 in the support 54, so - 7 that the carriage moves smoothly from the ladder to the support. The eight wheel system means that all times there are at least two wheels on each side of the trolley engaged in a track thus keeping it in the correct orientation ready for moving from one section of track to another. The four wheels or rollers 58 to each side of the lift carriage or trolley mechanism ensures that the lift carriage or trolley rolls l'reely from the ladder section of track into the support structure located in the parallelogram frame section 54. This happens when the trolley moves from the top of the ladder track into the parallelogram frame track ready to move up and away from the hatch.

This also works in reverse. The eight wheel system means that all times there are at lo least two wheels on each side of the trolley engaged in a track thus keeping it in the correct orientation ready for moving from one section of track to another.

Fig 3 shows the state where the carriage 32 has moved fully up into the support 54 where it contacts end stops, and continued pull on the rope or wire 34 has started to pull the movable part of the frame upwards, the wire being taken up by motor 38, pulley 36 and a further pulley 52 at the front of the movable part of the .

:,: . frame. The parallel linkages start to pivot upwards and fold as shown in Fig 4, the front links 46, 46a and hence the support 54 maintaining the same attitude during pivoting motion because of the properties of the parallelogram linkage until the fully ' ' 20 upright position of I; ig. 5 is reached, where the links 48, 48a are upright and about the posts of the portal structure 40. At this time the carriage has been moved clear of the :'. hatch and also some distance above the hatch, typically waist height, so that loads can . be removed from the load platform without the user having to bend to ground lcvcl.

Furthermore, movement of the load requires only a single wire or cable to be attached to the lift carriage, and the load carriage has a continuous smooth movement path up the ladder, onto the support and to the fully raised position. It will be appreciated that lowering a load through the hatch is the reverse of the procedure described above.

It will be seen therefore that this invention provides an el'ficient, safe and cost effective means of raising and lower large or heavy goods through the same loft hatch - 8 as the access ladder. The present embodiment may use the following sequence of operations: The loft loader has an integrated set of deep tread aluminium steps which can fold out ol' the loft as do conventional loft ladders. The operator can use the loft loader's steps independently of the loft loading mechanism if he just wants to access the loft space.

The operator activates the key operated switch to power up the loft loader.

The operator can then choose to operate the loft loader from the base of the steps or from within the loft itself. This is due to the provision of multiple o "plug in" locations (not shown) for the wired remote control.

Upon operating a down button on a remote control (not shown) the parallelogram mechanism lowers the platform keeping it level until it reaches the top of the steps where the lift carriage can run down inside the extrusions that form the sides of the ladder.

The lift platform keeps descending until it operates a kill switch at the bottom of its descent.

. The same process is carried out in reverse during the platform's ascent. When . . . the platform reaches the top of the ladder the parallelogram mechanism lilts . the platform away from the hatch keeping it level until a kill switch is activated stopping the mechanism at its furthest point of travel. The operator can then ascend the steps and unload the platform.

: In particular the embodiment described (which can be retro-fitted in existing homes) above has the following features and benefits: 25. The loft loader folds away neatly into the loft hatch as do most conventional loft ladders.

It has been designed to fit between standard spaced ceiling joists.

It will lift up to 50kg with a built in safety factor of double. The max recommended lifting weight ova human is 25kg. - 9

The loft loader may be provided with a key operated power switch. This safety feature prevents accidents by ensuring the loft loader cannot be operated by children who do not have a key.

The loft loader may be provided with an emergency stop button which means s in the event of an accident the loft loader can easily be powered off: An electronic control box for the drive motor may be provided with a current overload detector built in which means that if the winch stalls or an electrical fault occurs the loft loader powers olf automatically.

The use of"kill" switches ensure that the loft loader's climb and descent is lo automatically controlled.

The loft loader lifts the load away from the hatch keeping it level so that the operator can climb up and unload the platform. Thus it enables single-handed operation.

Modifications may be made to the embodiment described above without departing from the invention. For example Factories, workshops, offices and shops with either mezzanine floors or loft spaces may also largely benefit from the present ladder arrangement. Permanent standing versions could be installed if a fold away * . ladder is not desired. The the rollers on the trolley could in fact be replaced with sliders i.e. they would remain in the channel as do the rollers but slide as opposed to roll. 1he above mechanism may also work with grooved rollers on the outside but it : would be desirable to provide a design feature to ensure the lifting platform when : loaded did not lever the trolley away from the ladder during operation. Also it is desirable that the rollers should be guided into the top mechanism smoothly. 2s

Claims

Apparatus for lifting a load, comprising: a hatch for a floor or ceiling; a ladder fitted to one side of said hatch and extendable through and below the hatch; a lift carriage for fitting onto the ladder for movement upwards or downwards along the ladder; a hoist attachable to the lift carriage for raising or lowering thereof; and a frame for fitting to the floor or ceiling behind the hatch having a movable lo portion provided with a support for receiving the lift carriage on hoisting said lift carriage from said ladder through the hatch, said movable portion being arranged on further hoisting of the lift carriage to pivot to from a lowered position where the support is in register with the top of the ladder to a raised position in which the lift carriage becomes located above and behind the hatch.
2. The apparatus of claim 1, wherein the support is provided with carriage receiving formations resembling those portions of the ladder onto which the lift carriage fits, whereby said lift carriage is smoothly moveable from said ladder onto . said support.
3. The apparatus of claim 1 or 2, comprising four bar parallelogram linkages for . . guiding the support for movement between raised and lowered positions, the support forming one end of' said parallelogram linkages and the other end of said parallelogram linkages being fixed behind the hatch.

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4. The apparatus of any preceding claim, wherein opposed sides of the ladder are flanged to define tracks, and opposed sides of the lift carriage have wheels for running along said tracks.
5. The apparatus of any preceding claim, wherein the ladder and the lift carriage have inter-engaging formations such that the lift carriage is captive when on the ladder.
6. The apparatus of claim 5, wherein opposed sides of the ladder have inturned flanges defining said track and opposed sides of said lift carriage have outwardly projecting wheels that run in said track. - 11
7. Apparatus for lifting a load through a hatch through a floor or ceiling, said apparatus being substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
8. I;or use with the apparatus of any of claims 1-7, a frame for fitting to a floor or ceiling behind a hatch, said frame comprising a fixed portion for attachment behind the hatch, a movable portion pivoted to the fixed portion and provided with a support for receiving the lift carriage from the ladder, said pivoting connection between the fixed and movable portions permitting movement between a lowered position where the support can register with the top of the ladder and a raised position lo in which the lift carriage becomes located above and behind the hatch.
9. The frame of claim 8, wherein the support is provided with carriagereceiving formations resembling those portions of the ladder onto which the lift carriage fits, whereby said lift carriage is smoothly moveable from said ladder onto said support.
10. The apparatus of claim 8 or 9, comprising four bar parallelogram linkages for Is guiding the support for movement between raised and lowered positions, the support forming one end oi said parallelogram linkages and the other end of said parallelogram linkages being fixed behind the hatch. ..

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11. A frame structure constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in Figs 2-5 of the accompanying drawings. : ::