GB2484544A

GB2484544A - Portable crane assembly

Info

Publication number: GB2484544A
Application number: GB1017487.8A
Authority: GB
Inventors: Jeffrey Lee Crowder
Original assignee: CDR SYSTEMS Ltd
Current assignee: CDR SYSTEMS Ltd
Priority date: 2010-10-16
Filing date: 2010-10-16
Publication date: 2012-04-18
Also published as: GB201017487D0

Abstract

A portable crane 1 has a longitudinal beam 9 with first and second support members 11, 17, a pulley 25 and a winch 21. The crane 1 may be mounted to the rafters of a roof, for example, to raise glazing panels to be fitted. The crane 1 may alternately be mounted to the rungs of a ladder in order to raise items. Also disclosed are corresponding methods of usage of the crane.

Description

Portable Crane

FIELD OF THE INVENTION

This invention pertains generally to the field of portable cranes and hoists. More particularly, it relates to a crane for lifting loads up to raised positions having a plurality of rafters or joists (such as a roof, e.g. of a conservatory) or up a ladder. It further relates to corresponding methods for raising loads.

BACKGROUND OF THE INVENTION

Construction workers are increasingly required to lift heavier loads to raised platforms or locations and in many cases hazardous or fragile loads. In particular, the increased desire for glazed roofs, especially conservatories, coupled with the requirement or desire for improved thermal insulation has requires installers having to manually lift heavy glazing materials such as double or triple glazed sealed units to overhead installation positions. Typically, the worker has to arrange for lifting of the load overhead for installation or, at considerable expense, arrange for an external crane to assist. No adequate portable device is available to assist in lifting loads to a required location through rafters of a roof A further challenge faced by workers, such as construction teams, roofers, glazers or decorators, is safely lifting loads up a ladder. Even if a worker is accompanied, lifting a load manually up a ladder is difficult and hazardous.

When working alone, the worker faces a very difficult and hazardous job in lifting loads up ladders. There are some devices known which utilise a winch that may be affixed to a rung and the cable passed over the top rung or a pulley system located at the top rung. However, if simply passed over a rung, the load may result in imbalance of the ladder. By utilising a pulley system on the top rung, the load being lifted is not safely spread across the ladder and a worker is not well positioned to finely adjust the lifting if, for example, the load is to be lifted to an intermediate position up the ladder.

The present inventor has devised a system and apparatus that enables the aforementioned problems to be overcome and enable hoisting of loads to a raised location through rafters of a roof and/or to enable safe and simple lifting of loads up a ladder.

PROBLEM TO BE SOLVED BY THE INVENTION

There is a need for improvements to lifting devices to assist roofer and glazers in installing roofing components. There is a further need to assist workers in lifting loads to specified locations using a ladder.

It is an object of this invention to provide a portable crane that enables safe and efficient lifting of loads through the rafters or joists of a roof or raised floor.

It is a further object of this invention to provide a portable crane to enable a lone-worker to safely hoist a load accurately to a pre-determined height upaladder.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention, there is provided a portable crane for hoisting loads up to a raised platform or position characterized by a series of rafters or joists or up a ladder, the crane comprising a longitudinal beam provided with a pulley, said longitudinal beam being mounted to at least a first support member and a second support member being longitudinally separated along the length of the beam, the first and second support members being adapted for engagement with or mounting to or in association with the raised platform or position or with the ladder, and a winch means mounted at a position longitudinally separated from the pulley.

In a second aspect of the invention, there is provided a method of hoisting a load to a raised position characterized by a series of rafters or joists, the method comprising providing a portable crane as described above adapted to be positioned on at least two of said rafters or joists defining a gap through which the load is to be hoisted, by abutment of the support members on the respective rafters or joists, positioning the crane on said rafters or joists for support thereon, passing a cable from the winch via the pulley between the two rafters or joists, securing said cable to a load and raising the load to the desired height by operation of the winch.

In a third aspect of the invention, there is provided a method of hoisting a load to a specified position up a ladder, the method comprising providing a portable crane as described above adapted for engagement with at least two rungs of said ladder, positioning the crane such as to locate the pulley corresponding to the position the load is to be raised to and to provide the proximal end of the beam toward the lower end of the ladder, passing a cable from the winch via the pulley between rungs in the ladder for attachment to the load, and raising the load to the desired position by operation of said winch.

In a fourth aspect of the invention, there is provided a kit for a portable crane, the kit comprising at least two beam portions for telescopic connection to form a telescopic longitudinal beam, two struts mounted on respective slideable and securable mounts for slideable or fixedly mounting to said longitudinal beam, which struts are telescopically adjustable in length, two support members for mounting on said struts, a pulley (optionally formed on a slideable and securable mount for slidable mounting to the longitudinal beam) and a winch provided with a cable, said winch for mounting on the longitudinal beam or a strut, the components being securable by provided securing means.

In a fifth aspect of the invention, there is provided a ladder and crane assembly for accessing and hoisting loads to a raised position defined by a series of rafters or joists, the assembly comprising a ladder fitted with a portable crane as described above, which is adapted for fitment to said ladder.

ADVANTAGES OF THE INVENTION

The portable crane of the invention enables the safe and convenient lifting of loads to a specified raised location such as a roof (or up a ladder), part way up a wall on a ladder (e.g. to a window aperture or to fixing location on a wall) without the need for overhead lifting of heavy weights. Thereby a roofer or glazer may comfortably and accurately raise a sealed glazing unit to the desired location. The crane is adaptable for positioning over joists of different sizes or onto a ladder (e.g. a roof ladder configured for engagement with rafters or joists, such as the rafters of a conservatory) and thus may be used in various configurations directly on the joists or fitted to a roof ladder. The crane is strong, lightweight and portable.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic, in perspective view, of a portable crane according to one embodiment of the present invention.

Figure 2 shows, in perspective view, a portable crane according to a second embodiment of the present invention.

Figure 3 shows a view of a portable crane according to a second embodiment of the present invention.

Figure 4 shows a view of an arrangement for securing the hoist to a glazing unit for one use of the portable crane according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The portable crane according to the present invention is adaptable or may be adapted to several uses and to one or several configuration for hoisting a load to a raised position, such as a platform or position associated with a series of rafters or joists (e.g. a roof, conservatory roof, attic floor or upper floor in construction of a building) or to a raised position accessed or accessible by ladder (e.g. in substitution of manually carrying a load up a ladder, or raising scaffolding, in order to, for example, fit an air conditioning unit to a pre-determined location on a wall).

The portable crane in accordance with the invention comprises a longitudinal beam mounted to at least a first support member and a second support member, which support members are longitudinally separated along the length of the beam. The first and second support members are adapted for engagement with or for mounting to or in association with a ladder or a joist or rafter arrangement.

A hoist arrangement, which is typically a winch, pulley and cable arrangement, is provided to enable a load to be raised as required by the cable or rope, the supported longitudinal beam typically bearing the load. Where a winch and pulley arrangement is provided, the pulley is provided in, on or mounted in association with the longitudinal beam and the winch is longitudinally separated from said pulley and mounted relative a different position on the beam.

The crane may be adapted to a fixed configuration (which may be selected from numerous possible configurations according to a variety of uses) for one particular purpose and arrangement or may be adaptable or adjustable in one or more ways (such as described herein) to enable its use in one or more ways in one or more arrangements.

The longitudinal beam may be provided as a fixed length beam or may be of adjustable length, e.g. by telescopic adjustment or by the provision of extensions which may be fitted to the beam.

Preferably, the beam is mounted to at least one or two supporting members by a strut extending from the beam to each supporting member.

Preferably, at least one or each strut is adjustable in length whereby the height of the beam from the supporting members may be varied as desired. Most preferably two struts are provided, protruding from one side of the longitudinal beam, for mounting the longitudinal beam to the respective supporting members. Preferably each of these struts is independently adjustable in length whereby the height and angle of the longitudinal beam may be adjusted relative the respective positions of the support members (e.g. on rafters or joists or on rungs of a ladder). The struts preferably protrude from the same side of the longitudinal beam and preferably in the same plane, but not necessarily at the same angle from the longitudinal beam.

Preferably, however, the struts protrude substantially perpendicularly from the beam. Optionally, especially where the struts are extendable to a large extent, the struts may be pivotally mounted to the longitudinal beam.

Optionally and alternatively, the longitudinal beam may be mounted to one or more of the supporting members directly (e.g. a supporting members may protrude directly from the beam) or via an alternative mounting means such as a triangular configured mount.

Optionally, one or more support mounts for mounting the beam to the support members, preferably struts, are adjustable in the longitudinal position from which the strut protrudes (e.g. by providing a strut on a collar about the longitudinal beam, which collar may be slideable along the length of the beam and securable by any suitable means, such as a pin and hole arrangement, e.g. using linch pins or the like). Accordingly, the relative longitudinal positions of the supporting members may be varied as required or desired.

A winch providing the hoisting means may be mounted onto the longitudinal beam. Optionally, the winch is mounted on the top (i.e. the surface of the longitudinal beam opposite that mounted to the support members) or on the bottom of the beam, but may instead be mounted on a side of the beam.

Alternatively, the winch may be mounted on a strut or a supporting member or on a winch supporting strut. In a preferred embodiment, the winch is mounted on the top of the longitudinal beam to allow additional clearance for operating the winch.

The longitudinal beam may have one end designated the proximal end, being the end of the beam that, in operation, the winch is proximal to. The proximal end of the beam, in use, is typically the end from which the beam extends away from a user or operator of the crane and is typically the end of the beam associated with a lower rung when mounted on a ladder and associated with a support resting on a lower part of inclined roof rafters or joists. A proximal portion of the beam (having a fixed configuration, or in any particular arrangement in the use of a beam having variable configuration, e.g. length) is that length of the beam closer to the proximal end. A distal portion of the beam is that length of the beam farther from the proximal end (and closer to the distal end).

The winch is preferably mounted at a position relative to the proximal portion of the beam and more preferably at a position relative to a proximal third of the beam (being a one third length of the beam closest to the proximal end). Where the length of the beam is considered in thirds, it may be designated as having a proximal third, a distal third and an intermediate third.

As mentioned above, the support members may be configured to be in fixed, but separated longitudinal positions relative the length of the beam or may be movable in the longitudinal direction relative to one another. Where the support members are longitudinally adjustable relative to one another (e.g. by way of being attached to struts that are capable of being adjusted to relatively different respectively longitudinal positions on the beam), one or two of the support members may be moveable.

Preferably, at least a first support member is positioned relative the proximal portion of the beam, preferably relative a proximal third of the beam.

More preferably, the beam is mounted on first support member by a strut protruding perpendicularly from the beam which protrusion is within 300 mm of the proximal end, optionally within 100 mm. In a preferred embodiment, the first support member is fixedly mounted to the longitudinal beam, whereby the longitudinal position of the first support member is not adjustable.

The second support member is be positioned relative to the longitudinal beam at a position longitudinally separated from the first support member and preferably relative an intermediate or distal portion of the beam.

The longitudinal beam is provided with a means for supporting and/or guiding a cable or rope (or wire) for use in lifting a load, which cable or rope (or wire) is to be hoisted using the winch. Such means for supporting and/or guiding the cable is preferably a pulley. The pulley may be a groove or channel through which a cable may run. Preferably, the pulley comprises a pulley wheel or arrangement of wheels over which the cable may run in hoisting a load. The pulley may be mounted above or below the longitudinal beam, or optionally to one side. Alternatively, the pulley arrangement may be mounted within an aperture or groove formed within the beam itself. The precise arrangement depends on the arrangement of winch and cable and other components of the crane. For example, where the winch is mounted at a location below the beam, the cable may pass through an aperture formed in the beam and run along the top the beam in longitudinal alignment therewith to a longitudinal grooved aperture in the beam fitted with a pulley, run over the pulley and down to the load to be raised.

Optionally, the pulley is positioned within a groove formed in the distal end of the beam or is mounted on or close to the distal end. Alternatively (and preferably), the same arrangement may be achieved for a winch mounted above the beam.

According to the above arrangements and preferred arrangements, there are essentially two configurations which may be adopted for the crane of the present invention. Optionally, a crane may be provided, having adjustable and moveable parts, to be able to achieve either configuration. In a first configuration, the second support member is positioned longitudinally distal to the first support member relative to the position of the pulley. In other words, the pulley is positioned relative the length of the longitudinal beam intermediate the first and second support members. In a second configuration, the second support member is positioned longitudinally proximal to the first support member relative the pulley. In other words, the second support member is positioned relative the length of the longitudinal beam intermediate the first support member and the pulley.

According to the first configuration, the longitudinal beam is preferably mounted on the second support member at a position in a distal portion, preferably a distal third of the longitudinal beam. The pulley may be positioned at any intermediate position (and optionally is adjustable to be located at any intermediate location -which is more achievable if the pulley is mounted on the underside of the beam and therefore does not require the cable to pass an aperture in the beam), but preferably at an intermediate third of the longitudinal beam and more preferably at approximately the mid-point of the length of the beam, whereby the load being lifted is evenly spread across the two support members.

According to the second configuration, the longitudinal beam may be mounted on the second support member at a position in the proximal or distal portion, e.g. relative a proximal, distal or intermediate third of the longitudinal beam. Preferably, the second support member is positioned relative the longitudinal beam at a distal or intermediate third of the beam. The pulley, according to this second configuration, is preferably mounted on or in the beam at a distal portion, preferably a distal third of the longitudinal beam. More preferably, the pulley is mounted within 300 mm of the distal end and optionally within 100 mm. In one embodiment, the pulley is mounted at the distal end or within a groove formed in the distal end.

In an embodiment in which the beam is extendable having a body portion and an extendable portion, the first support member is positioned in a proximal third of the body portion and the second support members is also mounted on the body portion whilst the pulley may be mounted on the extendable portion (which extends coaxially from within the body portion), preferably the distal end thereof.

The support members may take the form of any means for fixing, mounting, being supported or abutting rafters or joists or rungs or rims of a ladder.

There are, however, two main embodiments that are preferably utilized with the present invention.

In one embodiment, at least one and preferably two support members take the form of laterally extending cross-members. The laterally extending cross-members are each preferably configured (or preferably adjustable) for engagement or abutment with two adjacent but laterally separated joists or rafters, whereby each cross-member effectively bridges a gap between two joists or rafters. Abutment portions or feet may be provided on the cross-members, e.g. at the ends thereof, for abutment or engagement with the rafters or joists, which abutment portions or feet are optionally shaped for engagement with a pre-defined shape of rafter or joist. Optionally one or both cross-members, preferably at least the cross-member forming the proximal support member, are provided with rafter or joist engaging means. This may take the form, for example, of a bracket or clamp fixing about the rafter, or a securable strap, with the aim of reducing the likelihood of slippage, especially when applied to rafters having an incline.

Preferably, according to this embodiment, the cross-members are of adjustable lateral extent, whereby their length may be adjusted to bridge varying sizes of gaps between joists or rafters. More preferably, each of two cross-members (forming the first and second support members) are independently capable of adjustable lateral extent, whereby the crane may be adapted for use on rafters or joists which are not parallel, such as those rafters of a bowed roof or conservatory having rafters with a lesser separation closer the ridge or apex and a greater separation closer the eaves. Such variability in the length of such cross-members may be achieved by providing telescopically extendable cross-members or extensions thereto.

A crane according to this embodiment, and adopting either of the two aforementioned configurations, is particularly suitable for use in raising loads to a roof, e.g. of a conservatory from within the building and between gaps in rafters. For example, a crane according to this embodiment may be used to raise glazing for fitting to a conservatory roof, e.g. for overhead work, and has the particular advantage of being able to hold glazing (or other components) in position for securing from beneath, without placing strain on the worker or the securing means whilst being fitted. Further, the crane may be utilized to raise a glazing unit at a slight but consistent angle such that it may pass through the aperture and placed on ridges to which it is to be fixed. Whilst either configuration mentioned above (i.e. a pulley configured intermediate the support members or a pulley configured distal the support members) may be used, for this embodiment the first configuration is preferred, whereby the pulley is configured intermediate the first and second support members. The first configuration further allows heavy loads to be lifted negating the need for a counterbalance (as compared with an extended beam, or boom, mounted hoist).

When used on a roof of substantial incline, it is prefened to secure the crane in some way. One method for securing the crane, on a pitched roof, is to provide a ridge engaging means, such as a hook, linked by a cable to the crane body, typically to the longitudinal beam, e.g. through an aperture formed in the distal end.

In another embodiment, at least one and preferably two support members take the form of rod-receiving members. According to this embodiment, the support members take a form that is capable of receiving or mounting to any rod-like members. For example, the rod-receiving member may comprise a pair or series of hook members mounted on a bracket or any others suitable such rod- -10 -receiving member. Optionally the rod-receiving member is capable of being secured about the rod received therein. Preferably, the rod receiving member is a laterally extending receiving member having, for example, a u-shaped, v-shaped, three-sided square shaped or other such profile capable of receiving a rod of similar or different profile. Optionally, the rod-receiving member is a square profile having one open end (the bottom end), which is optionally pivotally attached or which may comprise securing means bridging the open end. Note, herein above, below, top and bottom are used relative the longitudinal beam wherein the side on which the support members are mounted may be designated the bottom side (or below).

The rod, for receipt by the rod-receiving member is preferably an extended bar member or the rung of a ladder.

In one, preferred, embodiment of this rod-receiving support member embodiment of the invention, each rod-receiving support member is a member capable of receiving or engaging with a rung of a ladder, whereby the crane may be affixed to or engaged with a ladder to be utilized as a ladder crane, or where the ladder is configured for use on a rafter or joist characterized raised platform or position, as a crane for such a purpose. Preferably, the crane according to this embodiment may be adaptable to be used in the manner of the first embodiment of the supporting member discussed above in which the support members are laterally extendable cross-members by providing laterally extendable bars suitable for abutting or engaging with joists or rafters which are sized for receipt by the rod-receiving members according to this embodiment.

Preferably, the rod-engaging means is sized in terms of its receiving profile as capable of receiving the rungs of a ladder to which it is to be mounted or engaged and more preferably of lateral extension of about the length of the ladder rungs to which it is to be mounted or engaged. Preferably, therefore, the rod-engaging means has a profile depth of up to 60 mm, preferably up to 30 mm and a profile width of up to 60 mm, preferably up to 30 mm and a profile (lateral) length of at least 100 mm, preferably at least 200 mm, more preferably at least 250 mi-n and most preferably no more than about 300 mm.

Preferably, the rod-receiving member is capable of being secured or locked about the rung of the ladder.

The ladder engaging crane according to this embodiment, may utilize either the first or second configuration referred to above (in terms of respective positions of the second support member and pulley to the first support member). For the purpose of use as a ladder crane, that is for lifting loads to a specified location up a ladder, the second configuration where the beam extends from the first support member beyond the second support member boom-like to a pulley provided on a distal portion of the beam. According to this arrangement, the two rung-receiving members may be adjusted to fit two rungs on the ladder whereby the proximal end of the crane is fitted to a lower rung of the ladder sufficient to enable an operate to operate the winch from the ground or lower rung and the beam extends to a position whereby the cable drops between rungs of a height to which the load is to be hoisted.

Accordingly, heavy loads may be lifted to a pre-determined location using a ladder. This is particularly useful for lifting loads to be affixed to a wall, such as a window frame or sealed glazing unit for fitting in the aperture of a wall, or for a section of guttering, signage or air conditioning units, where the location for the works is not associated with a platform upon which the load may be rested and which would otherwise require multiple workers, hazardous use of ladders or expensive alternative (such as a scaffold).

Alternatively, according to this embodiment, the rod-engaging members in the form of rung-engaging members may be adapted for engagement with a roof ladder, being a ladder adapted for use on a roof, e.g. where the ladder section is mounted to laterally extended rafter-or joist-abutting cross-members.

Preferably, the cross-members, in a similar manner to that discussed above, are capable of lateral extension so as to support the ladder on rafters or joists of different or variable separation. Optionally the ladder's cross-members are removably securable to the rafter or joists. In this arrangement, either configuration discussed above may be utilized, especially where the rung-receiving member of at least the first support member is capable of being locked -12-about the rung of the ladder (since counterbalance of any weight on a boom-like extended beam may be achieved by the distal extent of the ladder itself spreading the load along the rafters or joists).

In use, a roof-ladder, which may optionally be adjoined to or adjacent to a conventional ladder, is fitted with the crane by engagement of the rod-receiving members about two joists of the ladder, the proximal end of which is directed toward the eaves. The cable may be connected to a load by any suitable means, e.g. a hook, or vacuum pads/cups in the case of a glazing unit. When the beam and the pulley are positioned appropriately, the winch may be operated by an operator standing on the ladder adjoining or adjacent the roof ladder and the load hoisted to the desired height.

In these embodiments comprising a rod-receiving member as the first and second support member, both the first and second support members are preferably linked to the longitudinal beam by adjustable height struts, whereby the height and/or angle of the longitudinal beam may be adjusted relative the ladder upon which it is mounted.

Preferably, the rod-engaging means are releasably securable to a rod, such as a rung of a ladder, e.g. by a clamp or clip or chain.

The various components which are adjustable as discussed above may be configured for such adjustment by any suitable method or means known to the skilled person and many suitable such methods and means are known. For example, a beam, strut or cross-member may be extended by telescopic adjustment in which the body element and the core element are each provided with a series of securing apertures and securing pins (e.g. linch pin, hitch pin with r-clip or simple split-pin or r-clip) for fitting therein or each may be provided with an inter-engaging screw thread to allow the telescopic element to be extended or reduced by screwing in or out of its mate. Alternatively, extensions may be provided, which may be, for example, of the screw thread, clamp, aperture and pin or adaptor connection means.

Similarly, mounting means for the struts or pulley, which are adjustable in position, may take any suitable form, such as a cylindrical mount that -13 -may be tightened about the beam by a strap or clamp, or which may be fixed using pins through aligned apertures or slots formed in each, or by other suitable such arrangement.

The winch of the crane is preferably provided with a ratchet mechanism which allows the drum of the winch to be rotated in only one direction to wind up the cable, the mechanism being able to be release to allow the cable to be unwound. The crane can then be operated single handed by a single operator.

The winch will preferably be hand operated, but can also be motorized.

The dimensions of the crane may be selected (or adapted) as desired for any particular purpose. Preferably, however, for use as a ladder crane or a crane for lifting glazing units up to a conservatory roof, the longitudinal beam may be selected to have a length fixed or adjustable between or within the range from 250 mm to 5000 mm, preferably 500 mm to 2500 mm, preferably from 600 mm to 2000 mm. Most preferably, the beam has an adjustable length from about 700 to 1000 mm to about 1100 to 1800 mm (or even 1500 mm), for example from about 800 mm to about 1200 mm in a preferred arrangement.

The struts, if utilized, may be of any suitable size and may selected to be fixed (or extendable) between or within the range 20 to 500 mm. Preferably, a proximal strut will be longer than a distal strut (to account for the incline on a ladder or roof) and if extendable will be extendable from a longer contracted length to a longer extended length, e.g. from 50 to 500 mm, preferably from 200 to 300 mm. A distal strut may, therefore, have a length of from 20 to 200 mm, preferably 30 to 100 mm and preferably is a strut having a length extendable from about 30 mm to about 50 mm.

In those embodiments having laterally extended cross-members (and laterally extendable cross-members), the cross-members are preferably sized in order to bridge the desired gap between rafters or joists. Typically, however, they will be formed in a range of lengths from about 200 mm to about 3000 mm.

Where the cross-members are laterally extendable, it is preferred that they are laterally extendable between or within the range 300 mm to about 3000 mm, more -14-preferably in the range 500 to 2500 and still more preferably from about 600 to about 1500 mm (e.g. from 750 mm to 1000 mm).

The beam may be of any suitable profile, e.g. triangular, square, rectangular, oval or circular, but is preferably of circular profile forming a tubular beam. Similarly, for the struts and cross-members where utilized.

The crane, and especially the beam and struts, may be formed of any suitable material. Preferably, the beam and struts are formed of material that is strong, load bearing but relatively lightweight. For example, they may be formed of stainless steel or other metal, reinforced plastic (e.g. composite materials). Preferably, the beam and struts are formed of a high tensile aluminium tubing, which is preferably an anodized tubing.

The crane may be adapted to lift any suitable weight, e.g. up to about 1000kg, or up to 500 kg or up to about 250 kg.

Preferably, the crane is capable of being provided in a kit for assembly to enable storage, shipping and/or carriage. Accordingly, it is preferred that a kit for a portable crane is provide which comprises at least two beam portions for telescopic connection to form a telescopic longitudinal beam, two struts mounted on respective slideable and securable mounts for slideable mounting to said longitudinal beam, which struts are telescopic, two support members for mounting on said struts, a pulley formed on a slideable and securable mount for slideable mounting to the longitudinal beam and a winch provided with a cable, said winch for mounting on the longitudinal beam or a strut, the components being securable by provided securing means. Preferably, the said components are boxed for storage and distribution, which boxes are of dimension of no greater than say 150 cm by 50 cm by 50 cm.

Preferably the crane, for portability, has in at least one embodiment a weight in the range 5 to 50 kg, more preferably in the range 8 to 15 kg (e.g. about 10 kg).

In one embodiment suitable for portability and use on a ladder or in lifting loads, such as sealed glazing units, to a conservatory roof, the portable crane of the invention is manufactured of strengthened aluminium tubing, has a -15 -weight in the range of 8 to 15 kg, a longitudinal beam of a length extendable in the range 600 to 1500 mm and capable of lifting a load of up to 200 kg.

A ladder and crane assembly may preferably be provided for accessing and hoisting loads to a raised position defined by a series of rafters or joists, the assembly comprising a ladder, such as a roof latter such as that described above, fitted with a portable crane or provided with a portable crane adapted to fit such a ladder, the portable crane being as described above.

As discussed above, according to preferred embodiments of the invention, a load may be hoisted to a raised position characterized by a series of rafters or joists, by providing a portable crane as described above adapted to be positioned on at least two of said rafters or joists defining a gap through which the load is to be hoisted, by abutment of the support members on the respective rafters or joists, positioning the crane on said rafters or joists for support thereon, or by providing a portable crane adapted to be positioned on at least two rungs of a roof ladder that is adapted to be positioned on at least two of said rafters or joists; and passing a cable from the winch via the pulley between the two rafters or joists, securing said cable to a load and raising the load to the desired height by operation of the winch. The load, which may be, for example, a sealed glazing units for overhead fixing may be held in place by the crane while overhead work (e.g. to secure the sealed glazing unit in place) is carried out safely and reliable from above or below.

When used as a means for hoisting glazing unit, it is preferred that the cable or rope is connected to a vacuum cup or pair of vacuum cups designed for lifting glass thereby allowing the glazing unit to be secured in place about its peripheiy without the need for adjusting the unit to remove a lifting means. When provided with a pair of vacuum cups, they may be attached to the glazing unit such that the central lifting action by the crane maintains the glazing at a desired angle for fitment (corresponding, for example, to the pitch of the roof being glazed).

Preferably a pair of vacuum cups are mounted on a cross-bar that may be attached to the end of the cable, the cross-bar preferably being extendable -16 -to improve the stability of the load when raising and more accurately control adjustment of angle of the glazing unit being lifted.

The crane and method is particularly characterized by the operator being able to safely and accurately lift a glazing unit into place in the glazing aperture remote from the actual glazing aperture, reducing the risk of accident and of damage to the unit.

By utilizing a crane having a beam extendable to say 1200-1500 mm, glazing units having a length of up to and in excess of 2 m may be lifted into place in a roof glazing aperture.

Further, as discussed above, a load may be hoisted to a specified position up a ladder by providing a portable crane as defined above adapted for engagement with at least two rungs of said ladder, positioning the crane such as to locate the pulley corresponding to the position the load is to be raised to and to provide the proximal end of the beam toward the lower end of the ladder, passing a cable from the winch via the pulley between rungs in the ladder for attachment to the load, and raising the load to the desired position by operation of said pulley.

According to a less preferred embodiment of the above-described ladder crane embodiment of the portable crane, the support members may comprise rod-receiving members capable of receiving the rungs of a ladder, which rod-receiving means are of hooked form, whereby the craned may be adapted for mounting to an under-side of a ladder in use thereby allowing the ladder to remain in use without tripping hazard.

A crane of the present invention may be sized to lift a load according to any suitable height. Typically, the crane of a prefened embodiment may lift a load up to about 20 m (e.g. in a range 5 to 15 m).

A crane may be designed for operation on any roof inclination, preferably up to about 45 degrees (e.g. up to about 35 degrees).

The invention will now be described in more detail, without limitation, with reference to the accompanying Figures.

-17 -In Figure 1, a portable crane 1 is illustrated according to one embodiment of the invention in which the crane is adapted for hoisting a pane of glass (or sealed glazing unit) 3 onto a conservatory roof 5 (as the raised platform) having a series of inclined rafters 7. The crane 1 comprises a longitudinal beam 9 mounted via a strut member 10 to a first support member 11, in this case comprising a first cross-member 13 extending laterally and provided with feet 15 at each end for resting on the respective rafters 7 of the roofS. The first cross-member 13 is preferably laterally extendable (e.g. by telescopic or screw-thread extension) so that it may be adjusted for fitting roofs where the distance between respective rafters 7 is greater or less. The longitudinal beam 9 is further mounted to a second support member 17 which comprises a second cross-member 19 extending laterally and provided with feet 15 at each end for resting on respective rafters 7 of the roofS. The second cross-member 19 is preferably also extendable (e.g. by telescopic or screw-thread extension) so that it may be adjusted for fitting roofs where the distance between respective rafters 7 is greater or less. By having support members 11,17 comprising first and second cross-members 13,19 that are independently extendable, the crane may be adapted for use on roofs with non-parallel rafters, such as where the rafters are closer at the ridge than at the eaves, as is common in conservatory roofs.

The crane 1 is provided with a winch 21 mounted on the strut 10 and provided with a cable or rope 23 which feeds through a pulley 25 positioned on the longitudinal beam 9.

The longitudinal beam 9 has an end designated as a proximal end 27, being that end of the beam 9 to which the winch 21 is closer than the pulley 25. A proximal portion 29 of the beam 9 may be designated as that portion of the beam 9 nearer or nearest the proximal end 25, whilst the distal portion 31 may be designated as that portion of the beam 9 further or furthest from the proximal end (and nearer the distal end 33 of the beam 9).

The relative positions of the support members 11,17 in this configuration are that the first support member 11 is provided in the proximal portion 29 of the beam 9 adjacent the winch 21, preferably very close to the -18 -proximal end, whilst the second support member 17 is provided in the distal portion 31, preferably very close to the distal end. The pulley 25 is provided on a slideable mount 35 adjustable to various longitudinal positions, distal to the winch 21, along the length of beam 9 and between the first and second support members.

The slideable mount may be releasably secured at various locations along the length of the beam, by a pin 37 through receiving apertures in the mount and a correspondingly aligned one of a series of receiving apertures in the longitudinal beam 9. Thus a load, such a as a glazing pane 3, fixed by for example vacuum lifter cups 39 attached to the end of the cable or rope 23, may be safely lifted to roof level at a desired angle and alignment to allow fixing of a glazing pane to a required location in the roof.

The support members 11,17, especially the feet 15 of the first support member 11 may be provided with securing means (not shown) for securing the feet to the rafters, particularly where the roof is steeply inclined. On a pitched roof, a hook 41 may be provided to engage with the ridge 43 of the roof S and connected via a tether 45 to the distal end 33 of the longitudinal beam 9.

In use, the crane 1 may be utilised by an operator on the roof or preferably atop a ladder raised against the eaves in reach of the proximal end, whereby the winch may be operated by the operator on the ladder to hoist the load to the desired location, according to the relative position of the pulley.

The portable crane illustrated in Figure 1 takes a configuration referred to herein as a first configuration in which the pulley is located intermediate the first and second support members.

In Figure 2, a portable crane 1 is illustrated according to a second embodiment of the invention in which the crane 1 is adapted for hoisting a load 47 up a ladder 49. Longitudinal beam 9 is mounted via a first extendable strut 51 extending perpendicularly from a fixed position at a proximal portion 29 of the beam 9 to a first support member 11, in this case a rod-receiving member 53, which is shaped to receive a rod, which is in this case a rung 55 of the ladder 49 and positioned thereon. A second extendable strut 57 extends from a securable slideable mount 59 on an intermediate portion 63 (intermediate a proximal portion -19 - 29 and distal portion 31) of the beam 9 to a second support member 17, in this case a second rod-receiving member 61, which is shaped to receive a rod, which is in this case a rung 55 of the ladder 49. The second extendable strut 57 is extended to a lesser height than the first extendable strut 51 to allow the angle of the beam 9 to be an adjusted desired angle so that the distal end 33 protrudes between two rungs 55 to allow the load 47 to be lifted.

A winch 21 is mounted at a proximal portion 29 of the beam 9 adjacent the first extendable strut 51. A pulley 25 is in integrated into the beam 9 by mounting it in an aperture formed at the distal end. The cable 23 extends from the winch 21 through an aperture in the proximal portion 29 of the beam 9 and extends closely aligned to the beam 9 over the pulley 25 and is connected to the load 47 by hook 65.

Optionally, the first and second rod receiving members 53,6 1 are provided with securing means (not shown) to secure the rod receiving means to therungs55.

Accordingly, a load may be safely winched up to a location up a ladder with minimal risk to upsetting the balance of the ladder.

The portable crane illustrated in Figure 2 takes a configuration referred to herein as a second configuration in which the second support member is located intermediate the pulley and the first support member.

In Figure 3, a portable crane 1 having an extendable beam 9 and configured according a second configuration as herein defined, is provided with a winch 21 on the top side of the beam 9. The winch 21 is mounted adjacent a fixedly mounted strut connecting the beam to the first support member close to the proximal end 27. A second cxtendable strut 57 is provided on the body portion 65 of the beam 9. The first and second support members are in the form of rung-receiving rod-receiving members 53 having open (or three-sided) square profile and capable of being secured to said rungs.

Figure 4 illustrates a vacuum cup arrangement 67 to be attached to a cable 23, in which vacuum cups 69 are mounted on the ends of an cxtendable -20 -cross-member 71 whereby the balance and angle of a sealed glazing unit to be hoisted may be carefully controlled.

The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.

Claims

CLAIMS: 1. A portable crane for hoisting loads up to a raised platform characterized by a series of rafters or joists or up a ladder, the crane comprising a longitudinal beam provided with a pulley, said longitudinal beam being mounted to at least a first support member and a second support member being longitudinally separated along the length of the beam, the first and second support members being adapted for engagement with or mounting to or in association with the raised platform or ladder, and a winch means mounted at a position longitudinally separated from the pulley.
2. A portable crane as claimed in claim 1, wherein the longitudinal beam is mounted on the first support member via a first mounting strut and, optionally, is mounted on the second support member via a second mounting strut.
3. A portable crane as claimed in claim 2, wherein the mounting struts are of adjustable height, whereby the height of the beam from the support members may be adjusted and/or the angle of the beam relative the raised platform or ladder may be adjusted.
4. A portable crane as claimed in any one of claims 1 to 3, wherein the longitudinal beam is adjustable in length.
5. A portable crane as claimed in any one of claims 1 to 4, wherein the relative positions of the support members may be adjusted relative the longitudinal dimension of the beam.
6. A portable crane as claimed in any one of claims 1 to 5, wherein the beam has a proximal end being that end of the beam to which the mounted winch is closer and a distal end being the other end from the proximal end, wherein the beam has a proximal portion, being that portion of the length of the beam nearer -22 -the proximal end and a distal portion being that portion of the length of the beam further from the proximal end and wherein the winch is mounted at a position relative within a proximal portion of the beam.
7. A portable crane as claimed in claim 6, wherein the proximal portion comprises no more than one third of the length of the beam.
8. A portable crane as claimed in claim 6 or claim 7, wherein the first support member is positioned relative the proximal portion of the beam.
9. A portable crane as claimed in claim 7 or claim 8, wherein the beam comprises a proximal third, being a one third length of the beam closest to the proximal end, a distal third, being a one third length of the beam farthest from the proximal end and an intermediate third being a one third length of the beam intermediate the proximal and distal thirds and wherein the second support member is positioned relative an intermediate or distal third of the beam and the pulley is positioned distal to the second support member.
10. A portable crane as claimed in claim 7 or claim 8, wherein the beam comprises a proximal third, being a one third length of the beam closest to the proximal end, a distal third, being a one third length of the beam farthest from the proximal end and an intermediate third being a one third length of the beam intermediate the proximal and distal thirds and wherein the second support member is positioned relative a distal third of the beam and the pulley is positioned intermediate the first and second support members.
11. A portable crane as claimed in any one of the preceding claims, wherein the first support member and/or the second support member is a cross member adapted for abutment with rafters or joists at a raised position to which a load is to be lifted, whereby the crane may be supported on said rafters or joists. -23 -
12. A portable crane as claimed in claim 11, wherein each of the first and/or second cross-members laterally extend substantially perpendicular the longitudinal beam.
13. A portable crane as claimed in claim 11 or claim 12, wherein the first cross member and/or the second cross member is laterally extendable whereby they may support the crane on rafters or joists of varying degrees of separation.
14. A portable crane as claimed in claim 13, wherein the first cross member is extended to a greater extent than the second cross-member whereby the crane may be supported on a pair of rafters or joists of decreasing separation on the incline.
15. A portable crane as claimed in any one of claims 11 to 14, wherein the cross-members each comprise two abutment portions for abutment with respective rafters or joists and optionally wherein at least the abutment portions of the first support member are configured for securing to the rafters orjoists to prevent slippage.
16. A portable crane as claimed in any one of claims 1 to 10, wherein first support member and/or the second support member is a rod-receiving member which is configured for receiving or engaging with a rod.
17. A portable crane as claimed in claim 16, wherein the rod is the rung of a ladder.
18. A portable crane as claimed in claim 16, wherein the rod is an extended and/or extendable bar adaptable for abutment against a pair of rafters or joists.
19. A portable crane as claimed in any one of claims 16 to 18, wherein the rod-receiving member comprises an open, three sided square profile.

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20. A portable crane as claimed in any one of claims 16 to 19, wherein the rod-receiving member is releasably securable to the rod.
21. A portable crane as claimed in any one of claims 16 to 20, wherein the rod-receiving member is substantially the length of a rung of a ladder to which it is to be mounted.
22. A portable crane as claimed in any one of the preceding claims wherein the beam is of a length in the range 500 mm to 1500 mm.
23. A method of hoisting a load to a raised position characterized by a series of rafters or joists, the method comprising providing a portable crane as claimed in any one of claims 1 to 22 adapted to be positioned on at least two of said rafters or joists defining a gap through which the load is to be hoisted, by abutment of the support members on the respective rafters or joists, positioning the crane on said rafters or joists for support thereon, passing a cable from the winch via the pulley between the two rafters or joists, securing said cable to a load and raising the load to the desired height by operation of the winch.
24. A method of hoisting a load to a specified position up a ladder, the method comprising providing a portable crane as defined in any one of claims 1 to 22 adapted for engagement with at least two rungs of said ladder, positioning the crane such as to locate the pulley conesponding to the position the load is to be raised to and to provide the proximal end of the beam toward the lower end of the ladder, passing a cable from the winch via the pulley between rungs in the ladder for attachment to the load, and raising the load to the desired position by operation of said pulley.
25. A kit for a portable crane, the kit comprising at least two beam portions for telescopic connection to form a telescopic longitudinal beam, two struts mounted on respective slideable and securable mounts for slideable mounting to said -25 -longitudinal beam, which struts are telescopic, two support members for mounting on said struts, a pulley formed on a slideable and securable mount for slideable mounting to the longitudinal beam and a winch provided with a cable, said winch for mounting on the longitudinal beam or a strut, the components being securable by provided securing means.
26. A ladder and crane assembly for accessing and hoisting loads to a raised position defined by a series of rafters or joists, the assembly comprising a ladder fitted with a portable crane as defined in any one of claims 1 to 22 adapted for fitment to said ladder.
27. A portable crane as hereinbefore defined with reference to the drawings.-26 -