WO1997008407A1 - A suspension member in a work platform - Google Patents

A suspension member in a work platform Download PDF

Info

Publication number
WO1997008407A1
WO1997008407A1 PCT/SE1996/001048 SE9601048W WO9708407A1 WO 1997008407 A1 WO1997008407 A1 WO 1997008407A1 SE 9601048 W SE9601048 W SE 9601048W WO 9708407 A1 WO9708407 A1 WO 9708407A1
Authority
WO
WIPO (PCT)
Prior art keywords
coupling
bridge
cradle
centre portion
mast
Prior art date
Application number
PCT/SE1996/001048
Other languages
French (fr)
Inventor
Sven-Erik Wiklund
Original Assignee
Alimak Ab
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Alimak Ab filed Critical Alimak Ab
Priority to AU68417/96A priority Critical patent/AU6841796A/en
Publication of WO1997008407A1 publication Critical patent/WO1997008407A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F11/00—Lifting devices specially adapted for particular uses not otherwise provided for
    • B66F11/04—Lifting devices specially adapted for particular uses not otherwise provided for for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G1/00—Scaffolds primarily resting on the ground
    • E04G1/18—Scaffolds primarily resting on the ground adjustable in height
    • E04G1/20—Scaffolds comprising upright members and provision for supporting cross-members or platforms at different positions therealong

Definitions

  • the invention relates to a suspension member in a work platform, having a motor-driven lift bridge, for connecting two sections of the bridge with a centre portion, which is drivable along a vertical mast and carries a drive unit for driving the centre portion and the bridge sections connected thereto along the mast.
  • the invention is intended to be used in a work platform, having a plurality of masts, especially in a twin mast structure, i e a twin mast platform, having two spaced vertical masts, carrying a centre portion each.
  • Such work platforms have been known for quite a long time. Generally they are dismountable but they may be permanently installed, as well, and may be utilized in various fields, primarily in the building industry, however, for conveying materials and the staff to a desired work level, at which the work in question is to be done, such as the installation or the repair of windows in a building, or other kinds of facade works.
  • each centre portion provided for and carried by each mast, each centre portion having a drive unit, comprising one or more drive motors and a drive chain for transmitting the drive power to a tooth gear, engaging a corresponding tooth rack of the mast in order to drive the centre portion upwardly or downwardly, in dependence of rotary direction, along the mast.
  • each centre portion is equipped with guide and bearing rolls spaced from each other for rolling on the corresponding guide and bearing races of the respective mast.
  • a bridge including a number of connected sections, each of which being comprised of a lower supporting frame work and a floor portion, supported by the frame work.
  • a bridge portion extends generally horizontally from each side of the mast and each bridge portion may consist of a number of joined sections.
  • a span extends between adjacent masts and is connected to the corresponding centre portions of the masts.
  • a bridge portion extends from each of the extreme masts as a continuation of the span at the other side of the mast in question.
  • peripheral equipment such as control equipment for controlling the drive means and safety devices, such as guard rails and catches, releasing at critical speeds, load sensors and limit switches, which stop the drive at a critical load and the power supply to the motors upon reaching the limit positions of the bridge, respectively.
  • safety devices such as guard rails and catches, releasing at critical speeds, load sensors and limit switches, which stop the drive at a critical load and the power supply to the motors upon reaching the limit positions of the bridge, respectively.
  • a levelling device is provided as a further safety provision, which keeps the bridge in an essentially horizontal position.
  • the object of the invention is to provide a solution, which reduces the load of the bearing means of the work platform, thereby extending the endurance and reducing the need of maintenance and repair.
  • Fig 1 is a schematically drawn, front elevational view of a work platform in accordance with the invention
  • Fig 2 is a side elevational view of the platform of fig 1
  • Fig 3 is a top view of the work platform of figs 1 and 2
  • Fig 4 is a top view at a larger scale of a coupling cradle of the invention comprised in the system, and
  • Fig 5 illustrates at a larger scale the coupling cradle of fig 4 mounted between two platform sections.
  • Fig 1 shows a work platform 1, having two centre portions 3, each of which being drivable along a vertical mast.
  • the centre portions comprise drive means 7, including motor(s) and a gear train, which at the end has a gear wheel in engagement with a straight tooth rack, connected to a respective mast, thereby driving the centre portion 3 upwardly and downwardly along the mast 5 in dependence of the drive direction of the motor(s) .
  • the essentially rigid centre portion 3 surrounds three sides of the mast 5 and comprises guide rolls rolling on bearing races of the mast 5 in order to resist the horizontal forces which are derived from the load moments of the different parts of the work platform 1.
  • the bridge which is supported by masts 5 and centre portions 3, is constituted by a central span 9, extending between the masts and being composed of four sections in this case, and wings 11, 11', each protruding from respective mast and in this case consisting of one single section 10.
  • Each of the sections is made up of a lattice structure supporting a floor and racks 13.
  • At the end of each section connecting members are provided for connection to corresponding connecting members of the centre portion 3 or of an adjacent section 10.
  • the wings 11, 11' may consist of more than one section 10 and the central span 9 may consist of more or less sections 10 than shown in the drawings.
  • these sections have two upper beams, lying essentially in a horizontal plane, and on which the floor rests, and a lower beam located in the middle between the upper beams.
  • the beams are united by struts, thus providing a rigid lattice structure.
  • Figs 4 and 5 illustrates at a larger scale the particular support structure, used in accordance with the invention for reducing the load of the bearing means and the guide rolls of the platform.
  • this structure consists of a coupling cradle 15 having a central beam 17, which is generally parallel to the sections 10 of the work bridge, when assembled.
  • a central beam 17 In the middle of the central beam there is a bore 19 for a pivot, rigidly associated with the centre portion. The axis of the bore 19 is perpendicular to the logitudinal extension of the central beam 17.
  • Two parallel upper coupling beams 21, 21' are rigidly associated with the upper face of the central beam 17 and extend transversely thereto.
  • Each coupling beam has a couple of coupling lugs 22, 22' for bolting to corresponding coupling lugs, provided at the upper beams of the sections to be connected to the coupling cradle 15.
  • the coupling cradle has the shape of an H.
  • a rigidifying spacing strut 24 is provided at the end of the coupling beams 21, 21' . This strut is not absolutely necessary, but merely an advisable feature. More struts or other rigidifying means may be provided for stabilizing the coupling cradle 15.
  • the coupling of the coupling cradle 15 to the bridge sections 10 is particularly well shown in fig 5.
  • the cradle is disposed on a pivot, which is attached to depending coupling flanges 25 or analogous members of the centre portion 3, in which bores 27 are provided for recieving the pivot.
  • said pivot extends in a horizontal plane, transversely to the longitudinal direction of the bridge, the coupling cradle 15 being rotatable without any restrictions about the pivot.
  • the complete bridge will aligne itself in correspondence to kind of load. Since the moments emanating from the load (dead load + useful load) of the wings counteract the moment derived from the load of the central span, in total, the required lateral forces, which are generated by the guide and bearing rolls against the bearing races of the mast, will be significantly reduced. Thereby the wear will be significantly reduced, resulting in a longer endurance.
  • the centre portion of the invention may also be used in a single mast structure.
  • the mechanism has to be blocked for preventing an excessive rotary motion about the single pivot.
  • excessive rotary motions automatically will be prevented due to the geometrical design of the structure, having two spaced pivots.
  • conventional control and safety devices are provided for controlling the drive and for preventing the occurence of dangerous occasions.
  • the inventive structure comprises a conventional levelling device, keeping the bridge generally horizontal in use.

Landscapes

  • Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Architecture (AREA)
  • Mechanical Engineering (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Forklifts And Lifting Vehicles (AREA)
  • Lift-Guide Devices, And Elevator Ropes And Cables (AREA)
  • Bridges Or Land Bridges (AREA)

Abstract

A work platform has a centre portion drivable along a vertical mast and generally horizontal bridge portions (10) provided on either side of the centre portion, said bridge portions (10) being connected to said centre portion by means of a suspension member (15). Said suspension member (15) is a coupling cradle (15), which is pivotable about a pivot, rigidly associated with said centre portion. The pivot extends generally transversely to the longitudinal direction of the bridge portions (10). The bridge portions (10) are coupled to the coupling cradle (15) by means of coupling members (22, 22'; 23, 23') thereon and the coupling cradle comprises a bore (19) by means of which said cradle is pivotably received on the pivot of the centre portion.

Description

A SUSPENSION MEMBER IN A WORK PLATFORM
The invention relates to a suspension member in a work platform, having a motor-driven lift bridge, for connecting two sections of the bridge with a centre portion, which is drivable along a vertical mast and carries a drive unit for driving the centre portion and the bridge sections connected thereto along the mast. In particular the invention is intended to be used in a work platform, having a plurality of masts, especially in a twin mast structure, i e a twin mast platform, having two spaced vertical masts, carrying a centre portion each.
Such work platforms have been known for quite a long time. Generally they are dismountable but they may be permanently installed, as well, and may be utilized in various fields, primarily in the building industry, however, for conveying materials and the staff to a desired work level, at which the work in question is to be done, such as the installation or the repair of windows in a building, or other kinds of facade works.
Work platforms of this type include the following members as main components:
- One or more spaced, vertical masts, which are built up from frame sections up to a desired height of up to 100 m. The masts comprise a straight and continuos tooth rack for cooperation with a corresponding tooth gear, provided on a centre portion, and continuous guide and bearing races located on each side of the mast, and which support horizontal forces produced by the dead weight and the load of the platform. - A centre portion provided for and carried by each mast, each centre portion having a drive unit, comprising one or more drive motors and a drive chain for transmitting the drive power to a tooth gear, engaging a corresponding tooth rack of the mast in order to drive the centre portion upwardly or downwardly, in dependence of rotary direction, along the mast. Further each centre portion is equipped with guide and bearing rolls spaced from each other for rolling on the corresponding guide and bearing races of the respective mast.
- A bridge, including a number of connected sections, each of which being comprised of a lower supporting frame work and a floor portion, supported by the frame work. In the single mast design a bridge portion extends generally horizontally from each side of the mast and each bridge portion may consist of a number of joined sections. In the mutiple mast design a span extends between adjacent masts and is connected to the corresponding centre portions of the masts. A bridge portion extends from each of the extreme masts as a continuation of the span at the other side of the mast in question.
Additionally, peripheral equipment is provided, such as control equipment for controlling the drive means and safety devices, such as guard rails and catches, releasing at critical speeds, load sensors and limit switches, which stop the drive at a critical load and the power supply to the motors upon reaching the limit positions of the bridge, respectively. In most cases in multiple mast stuctures a levelling device is provided as a further safety provision, which keeps the bridge in an essentially horizontal position. The structures described above constitute throughout conventional known art and will of that reason not be descibed further in detail hereinafter, since those known members do not form part of the invention.
In the prior art the bridge sections is connected directly to the respective centre portion by means of coupling lugs provided at the ends of the sections and of the centre portion, bolts being inserted through holes of the lugs to fix the members in relation to each other. This existing solution has proven itself. However, a problem that arises is that the guide and bearing rolls of the centre portion will be subjected to a relatively heavy load and a corresponding wear as a consequence, requiring continuous inspection, maintenance and possible replacement of these parts.
The object of the invention is to provide a solution, which reduces the load of the bearing means of the work platform, thereby extending the endurance and reducing the need of maintenance and repair.
According to the invention this object is reached by the features defined in claim 1.
A preferred embodiment of the invention will now be described hereinafter with reference to the annexed drawings, wherein:
Fig 1 is a schematically drawn, front elevational view of a work platform in accordance with the invention,
Fig 2 is a side elevational view of the platform of fig 1, Fig 3 is a top view of the work platform of figs 1 and 2,
Fig 4 is a top view at a larger scale of a coupling cradle of the invention comprised in the system, and
Fig 5 illustrates at a larger scale the coupling cradle of fig 4 mounted between two platform sections.
Fig 1 shows a work platform 1, having two centre portions 3, each of which being drivable along a vertical mast.
Conventionnally, the centre portions comprise drive means 7, including motor(s) and a gear train, which at the end has a gear wheel in engagement with a straight tooth rack, connected to a respective mast, thereby driving the centre portion 3 upwardly and downwardly along the mast 5 in dependence of the drive direction of the motor(s) . The essentially rigid centre portion 3 surrounds three sides of the mast 5 and comprises guide rolls rolling on bearing races of the mast 5 in order to resist the horizontal forces which are derived from the load moments of the different parts of the work platform 1.
In this twin mast structure the bridge, which is supported by masts 5 and centre portions 3, is constituted by a central span 9, extending between the masts and being composed of four sections in this case, and wings 11, 11', each protruding from respective mast and in this case consisting of one single section 10. Each of the sections is made up of a lattice structure supporting a floor and racks 13. At the end of each section connecting members are provided for connection to corresponding connecting members of the centre portion 3 or of an adjacent section 10. Naturally, the wings 11, 11' may consist of more than one section 10 and the central span 9 may consist of more or less sections 10 than shown in the drawings. In the shown example these sections have two upper beams, lying essentially in a horizontal plane, and on which the floor rests, and a lower beam located in the middle between the upper beams. The beams are united by struts, thus providing a rigid lattice structure.
Figs 4 and 5 illustrates at a larger scale the particular support structure, used in accordance with the invention for reducing the load of the bearing means and the guide rolls of the platform.
Fundamentally, this structure consists of a coupling cradle 15 having a central beam 17, which is generally parallel to the sections 10 of the work bridge, when assembled. In the middle of the central beam there is a bore 19 for a pivot, rigidly associated with the centre portion. The axis of the bore 19 is perpendicular to the logitudinal extension of the central beam 17. Two parallel upper coupling beams 21, 21' are rigidly associated with the upper face of the central beam 17 and extend transversely thereto. Each coupling beam has a couple of coupling lugs 22, 22' for bolting to corresponding coupling lugs, provided at the upper beams of the sections to be connected to the coupling cradle 15. For the connection of the lower beam of the sections 10 corresponding coupling lugs 23, 23' are attached at each side of the central beam 17. Thus, as seen from above, the coupling cradle has the shape of an H. Further, in the disclosed embodiment a rigidifying spacing strut 24 is provided at the end of the coupling beams 21, 21' . This strut is not absolutely necessary, but merely an advisable feature. More struts or other rigidifying means may be provided for stabilizing the coupling cradle 15.
The coupling of the coupling cradle 15 to the bridge sections 10 is particularly well shown in fig 5.
Again with reference to fig 1 the cradle is disposed on a pivot, which is attached to depending coupling flanges 25 or analogous members of the centre portion 3, in which bores 27 are provided for recieving the pivot. In the assembly said pivot extends in a horizontal plane, transversely to the longitudinal direction of the bridge, the coupling cradle 15 being rotatable without any restrictions about the pivot.
Thus, the complete bridge will aligne itself in correspondence to kind of load. Since the moments emanating from the load (dead load + useful load) of the wings counteract the moment derived from the load of the central span, in total, the required lateral forces, which are generated by the guide and bearing rolls against the bearing races of the mast, will be significantly reduced. Thereby the wear will be significantly reduced, resulting in a longer endurance.
The centre portion of the invention may also be used in a single mast structure. However, in such a device the mechanism has to be blocked for preventing an excessive rotary motion about the single pivot. In the twin mast structure excessive rotary motions automatically will be prevented due to the geometrical design of the structure, having two spaced pivots. Of course, though not described in detail, conventional control and safety devices are provided for controlling the drive and for preventing the occurence of dangerous occasions. Preferrably the inventive structure comprises a conventional levelling device, keeping the bridge generally horizontal in use.

Claims

1. Suspension member of a work platform, comprising:
- a vertical mast (5) ,
- a centre portion (3) , drivable along said mast (5) and having drive means (7) for driving said centre portion(3) along said mast (5) and guide and bearing means for transmitting moments and forces to said mast (5) ,
- a generally horizontal bridge composed of a number of bridge sections (10) , said centre portion (3) being disposed between and coupled to two bridge sections by means of coupling members, characterized in that said suspension member (15) is a coupling cradle, pivotable about a pivot, rigidly associated with said centre portion (3) , said pivot extending horizontally generally midway between said two bridge sections (10) and generally transversely to the longtudinal direction of said bridge, and in that said bridge sections (10) are connected, spaced from each other, with said coupling cradle (15) by means of coupling members and corresponding coupling members (22, 22', 23, 23') provided on said coupling cradle:
2. Suspension member as defined in claim 1, characterized in that said coupling cradle (15) comprises a central beam (17) , extending generally in parallel to said bridge and having a bore (19) for said pivot, said bore (19) extending transversely to the longitudinal extension of said central beam (17) .
3. Suspension member as defined in claim 2, characterized in that said cradle (15) comprises two parallel cross beams (21, 21') , generally lying in a horizontal plane and being associated with and transversely directed to said central beam (17) , each of said cross beams (21, 21') supporting upper coupling members (22, 22') for coupling to corresponding coupling members of a respective bridge section (10) , said central beam (17) and said cross beams (21, 21') forming an H, seen from above.
4. Suspension member as defined in claim 3, characterized in that said coupling cradle (15) comprises a lower coupling member (23, 23') located at each end of said central beam (17) for coupling to corresponding coupling members at said bridge sections (10) .
PCT/SE1996/001048 1995-08-23 1996-08-23 A suspension member in a work platform WO1997008407A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU68417/96A AU6841796A (en) 1995-08-23 1996-08-23 A suspension member in a work platform

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9502924-5 1995-08-23
SE9502924A SE504806C2 (en) 1995-08-23 1995-08-23 Suspension element for work platform coupling cradle

Publications (1)

Publication Number Publication Date
WO1997008407A1 true WO1997008407A1 (en) 1997-03-06

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1996/001048 WO1997008407A1 (en) 1995-08-23 1996-08-23 A suspension member in a work platform

Country Status (3)

Country Link
AU (1) AU6841796A (en)
SE (1) SE504806C2 (en)
WO (1) WO1997008407A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998046517A1 (en) * 1997-04-11 1998-10-22 Hek Manufacturing B.V. Elevating work platform
WO2009111875A1 (en) * 2008-03-11 2009-09-17 Hydro Mobile Inc. Elevating platform assembly
GB2499834A (en) * 2012-03-01 2013-09-04 Martin Pownall Transporter platform with base plate and cage for attachment to a hydraulic arm

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0624544A1 (en) * 1993-04-14 1994-11-17 Hek Manufacturing B.V. Platform, adjustable in height
WO1995023265A1 (en) * 1994-02-23 1995-08-31 Butler J Frank Modular scaffold assembly

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0624544A1 (en) * 1993-04-14 1994-11-17 Hek Manufacturing B.V. Platform, adjustable in height
WO1995023265A1 (en) * 1994-02-23 1995-08-31 Butler J Frank Modular scaffold assembly

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998046517A1 (en) * 1997-04-11 1998-10-22 Hek Manufacturing B.V. Elevating work platform
WO2009111875A1 (en) * 2008-03-11 2009-09-17 Hydro Mobile Inc. Elevating platform assembly
US8544604B2 (en) 2008-03-11 2013-10-01 Hydro Mobile Inc. Elevating platform assembly
GB2499834A (en) * 2012-03-01 2013-09-04 Martin Pownall Transporter platform with base plate and cage for attachment to a hydraulic arm

Also Published As

Publication number Publication date
SE504806C2 (en) 1997-04-28
SE9502924L (en) 1997-02-24
AU6841796A (en) 1997-03-19
SE9502924D0 (en) 1995-08-23

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