Mobile work platform and associated method for providing access to an exterior of a multistory existing building

Abstract

A mobile work platform system and a method for providing access to different levels of an exterior of a multistory existing building. The mobile work platform system comprises a support structure attached to the existing building, a plurality of suspension sets statically attached to the support structure, and a platform selectively attached to the suspension sets. A dynamic end of each translation mechanism is selectively connectable to anchoring points of the associated suspension set. In a platform resting position, the suspension set is attached to the platform at the anchoring points and the translation mechanisms are not loaded with a weight of the platform. During a platform displacement, the dynamic end of each translation mechanism is connected at one anchoring point of the associated suspension set, and each platform fixed attachment is detached from the associated suspension set and the translation mechanisms may move the platform.

Description

MOBILE WORK PLATFORM AND ASSOCIATED METHOD FOR PROVIDING ACCESS TO AN EXTERIOR OF A MULTISTORY EXISTING BUILDINGFIELD OF THE INVENTION

[0001] The present invention generally relates to the field of construction equipment. More specifically, the invention relates to a mobile work platform system designed to allow workers to safely access and work on the exterior of an occupied existing multistory building. The invention also relates to a method of providing access to different levels of the exterior of this existing building.BACKGROUND OF THE INVENTION

[0002] When construction or renovation work must be completed on an exterior of an existing multistory building, the usual solution is to install scaffolds close to the exterior walls of the existing building. More recent developments however have provided mobile platforms supported by one or more masts. Although this latter solution is advantageous over the former as it takes less space on the ground and allows better access to the existing building, they occupy some space of the ground.

[0003] To alleviate this drawback, multipoint suspended scaffolds may be used. This type of scaffolds is suspended from a top portion of the building and may be raised or lowered using motors generally located at the top of the building, hoisting through cables the mobile platform.

[0004] However, such motorization of the mobile platform is subject to stringent safety requirements in order to prevent accidents in case of failure of one of the motors. Safety factors are higher than those imposed on platforms not relying on a moving component to hold the platform in place. Safety devices such as brakes must be installed, which drives up the costs. Moreover, the high energy consumption of electric motors typically used in hoists for vertically displacing the platform requires a special attention and considerations on construction sites, asthese sites are typically not already provided with such available electrical power. Finally, the suspension cables are flexed repeatedly during the operation, inducing fatigue in the cable itself.SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to provide a work platform system for the construction industry that overcomes or mitigates one or more disadvantages of known pieces of construction equipment such as mobile work platforms, or at least provides a useful alternative.

[0006] The invention provides the advantages of taking a very small space on the ground and of potentially sheltering workers from the environment during construction works.

[0007] In accordance with an embodiment of the present invention, there is provided a mobile work platform system for providing elevated access to an exterior of a multistory existing building. The mobile work platform system comprises a support structure, a plurality of suspension sets, and a platform. The support structure has attachment points for attaching to the existing building. Each suspension set of the plurality of suspension sets is statically attached at its upper portion to the support structure and is provided with sequential anchoring points placed along the suspension set. The platform comprises a platform structure, fixed attachments and translation mechanisms. The fixed attachments are used to be selectively or removably attached at one of the anchoring points of an associated one of the suspension set. This allows the platform to be suspended from the support structure through the plurality of suspension sets. Each translation mechanism has a fixed portion connected to the platform structure and a dynamic end. Each translation mechanism is associated with one fixed attachment and with one suspension set. The dynamic end of each translation mechanism is selectively or removably connectable to one of the anchoring points of the associated suspension set. During a first platform resting position, the platform is at a first vertical distance from the support structure. The suspension set is attached to the fixed attachments and the translation mechanisms are notloaded with a weight of the platform. During a first platform displacement, the dynamic end of each translation mechanism is connected at one anchoring point of the associated suspension set, and each fixed attachment is detached from the associated suspension set. The translation mechanisms is then operative to retract or to extend so as to move the platform to a second position that is at a different vertical distance from the support structure than the first vertical distance.

[0008] Optionally, each suspension set is a cable set comprising a plurality of cables attached sequentially so as to form a chain of cables. Each cable has an anchor plate at its lower portion and each anchor plate comprises a plurality of the anchoring points therein. Within each cable set, a first one of the cables is a starting cable connected to the supporting structure. The subsequent cables within each cable set are extension cables.

[0009] Each translation mechanism may comprise an actuator. The actuator is fixedly attached to the platform structure at the fixed portion. This fixed portion can be placed above the dynamic end so that in case of failure of the actuator, the dynamic end abuts against the fixed portion and holds the platform.

[0010] The actuator may be operable between a first retracted position, a first extended position, a first transitional position and a second retracted position. In the first retracted position, the platform is at the first vertical distance from the support structure, each fixed attachment is attached at the lower portion of the associated starting cable so that a weight of the platform is supported by the starting cables, and the actuator of each translation mechanisms is unloaded from the weight of the platform.

[0011] In the first extended position, the platform is at the first vertical distance from the support structure, each fixed attachment is attached at the lower portion of the associated starting cable and the dynamic end of the actuator of each translation mechanism is attached at the lower portion of the respectively associated extension cable. At least one of the actuators and one of the associated extension cables supporting at least partially the weight of the platform.

[0012] In the first transitional position, the platform is at the first intermediate vertical distance from the support structure greater than the first vertical distance, the dynamic end of the actuator of each translation mechanism is attached at the lower portion of the associated extension cable, the actuator of each translation mechanism supporting at least partially the weight of the platform, and the lower portions of the extension cables are loaded with the weight of the platform.

[0013] In the second retracted position, the platform is at the second vertical distance from the support structure larger than the first intermediate distance, each fixed attachment is attached at the lower portion of the associated extension cable, each extension cable at least partially supporting the weight of the platform, and the actuator of each translation mechanism is unloaded from the weight of the platform.

[0014] Optionally, the platform structure may comprise vertical beams. Each fixed attachment and each actuator is located on a different one of the vertical beams. The dynamic end of the actuator of each translation mechanism slidingly engages the vertical beam on which it is located.

[0015] At least one of the translation mechanisms may comprise a lateral stabilizer. The lateral stabilizer comprises a sliding end connected to the vertical beam platform and a connecting end for connecting to the existing building. The sliding end is operative to slide on the vertical beam when the platform transitions from the first vertical distance to the second vertical distance, thereby maintaining the platform at a predetermined distance from the building.

[0016] The platform may further comprise a shell having a floor and a roof interconnected by a side wall. The side wall is placed so as to be distal from the exterior wall of the existing building when the mobile work platform system is installed on the existing building, thereby creating an enclosed interior space for workers. This enclosed workspace is delimited by the floor, the side wall, the roof and the exterior wall of the existing building. The enclosed space may also be internally compartmented with temporary divisions.

[0017] The platform may be equipped with an access hatch in the floor for allowing access to the platform and inside the shell, or the enclosed workspace.

[0018] The platform may further comprise a top seal and a bottom seal for sealing against an exterior wall of the existing building. The top seal may be located proximate the roof and the bottom seal may be located proximate the floor. The top seal and the bottom seal may be one of a flexible lip, a brush, a foam and an inflatable bladder. At least one of the top seal and the bottom seal comprise an energy-absorbing structure.

[0019] The support structure may be attached to an upper portion or to a median portion of the existing building.

[0020] In accordance with an embodiment of the present invention, there is provided a method for providing access to an exterior of a multistory existing building using the mobile work platform. The method comprises supporting the platform at the first vertical distance from the support structure by attaching each fixed attachment at the lower portion of the associated cable set so that the weight of the platform is supported by the cable set. The method also comprises retaining the translation mechanisms unloaded from the weight of the platform.

[0021] Optionally, the method may further comprise extending each translation mechanism so that the dynamic end reaches the anchor plate of a first one of the extension cable of an associated suspension set while the platform remains at the first vertical distance from the support structure; attaching the dynamic end of each translation mechanism to the anchor plate of the first one of the extension cables of each associated suspension set; disconnecting each fixed attachment from the anchoring plate of the first one of the cables; and supporting the weight of the platform using the translation mechanisms and the first extension cable of each cable sets.

[0022] The method may further comprises lowering the platform at a first intermediate vertical distance from the support structure that is larger than the first vertical distance, supporting at least part of the weight of the platform with thetranslation mechanisms, and loading the lower portion of the extension cables with the weight of the platform.

[0023] Moreover, the method may further comprise lowering the platform at the second vertical distance from the support structure that is larger than the intermediate vertical distance; attaching each fixed attachment at the lower portion of the associated extension cable; supporting at least partially the weight of the platform with the extension cables; and detaching the dynamic end of the translation mechanisms from the lower portion of the extension cables so as to unload the translation mechanisms from the weight of the platform.

[0024] An additional extension cable may be connected at the lower portion of each cable sets.

[0025] In accordance with another embodiment of the invention, there is provided a method for providing access to different levels of an exterior of a multistory existing building. The method comprises lowering from a first vertical position to a second vertical position a platform attached to a top portion of the existing building through a plurality of static starting cables loaded with a weight of the platform. The platform may be equipped with a plurality of actuators, each one of the plurality of actuators having a fixed portion and a dynamic end and being associated with at least one of the plurality of starting cables. The lowering comprises attaching each one of a plurality of first extension cables at a lower portion of one of the plurality of starting cables associated to one of the plurality of actuators; attaching the dynamic end of each one of the plurality of actuators to a lower portion of the associated one of the plurality of first extension cables; detaching the platform from the lower portions of the each one of the plurality of starting cables; and retracting the plurality of actuators, thereby lowering the platform. The retracting may be synchronized so that the platform remains level.

[0026] Optionally, the method may further comprise attaching the platform at the lower portion of each one of the plurality of first extension cables.

[0027] The method may also further comprise detaching the dynamic end of each one of the plurality of actuators from the lower portion of the associated one of the plurality of first extension cables.

[0028] Moreover, the method may further comprise attaching one of a plurality of second extension cables at the bwer portion of each one of the plurality of first extension cables.BRIEF DESCRIPTION OF DRAWINGS

[0029] These and other features of the present invention will become more apparent from the following description in which reference is made to the appended drawings wherein:

[0030] Figure 1 is an isometric view of an existing building where a mobile work platform system in accordance with an embodiment of the present invention is installed;

[0031] Figure 2 is a schematical partial cross-section along lines 2-2 of the mobile work platform system of Figure 1 ;

[0032] Figure 3 is a perspective view of a cable of a suspension set used in the mobile work platform system of Figure 1 ;

[0033] Figure 4 is a plan view from the top of the platform of the mobile work platform system of Figure 1 ;

[0034] Figure 5 is an axonometric view of a top or bottom seal including an energy-absorbing structure such a as those used in the mobile work platform system of Figure 1 ;

[0035] Figure 6 is the mobile work platform system of Figure 2 in a first step of vertical translation of the platform;

[0036] Figure 7 is the mobile work platform system of Figure 2 in a second step of vertical translation of the platform;

[0037] Figure 8 is the mobile work platform system of Figure 2 in a third step of vertical translation of the platform;

[0038] Figure 9 is the mobile work platform system of Figure 2 in a fourth step of vertical translation of the platform;

[0039] Figure 10 is the mobile work platform system of Figure 2 in a fifth step of vertical translation of the platform;

[0040] Figure 11 is the mobile work platform system of Figure 2 in a sixth step of vertical translation of the platform;

[0041] Figure 12 is the mobile work platform system of Figure 2 in a seventh step of vertical translation of the platform;

[0042] Figure 13a is the mobile work platform system of Figure 2 in an eighth step of vertical translation of the platform;

[0043] Figure 13b is the mobile work platform system of Figure 2 in place for a subsequent vertical translation of the platform; and

[0044] Figure 14 is an engineering detailed axonometric view of the translation mechanism and of a portion of the platform of the mobile work platform of Figure 10.DETAILED DESCRIPTION OF THE INVENTION

[0045] The present invention relates to a mobile platform typically used in the renovation or refurbishing of an existing multistory building, as well as to a method of providing access to different levels of the exterior of such an existing building.

[0046] Figure 1 depicts a typical installation of the mobile work platform system 10, which provides access to an exterior of a multistory existing building 12. The mobile work platform 10 is capable of moving up and down along a height of the existing building 12 so that its exterior can be renovated. The mobile work platform system 10 comprises a support structure 14, a plurality of suspension sets 16, and a platform 18. The support structure 14 is made of a plurality of supports 20. As shown in Figure 2, each support 20 is provided with attachment points 22 for attaching to an upper portion, typically the top 24, or a median portion (between a lower portion and the upper portion) of the existing building 12. The supports 20are typically bolted to structural beams of the top 24 of the building 12. Each support 20 comprises a supporting beam 28 attached to the supports 22 through a raising structure 30. The supporting beam 28 extends over the exterior wall 26 to support the platform 18 through the suspensions set 16.

[0047] Each suspension set 16 is statically attached to the one of the supporting beam 28. Statically means that the suspension sets 16 are simply hanging from the supporting beams 28 and are not attached to a motorized device such as a winch or a hoist. Advantageously, since they are statically attached, the suspension sets 16 are not subjected to cyclical bending and unbending. Each suspension set 16 is provided with sequential anchoring points 32 which are placed along the length of the suspension set 16.

[0048] The suspension sets 16 may typically either be a chain or cable. In the present example, the suspension sets 16 are made with cables. In fact, each suspension set 16 is made from a plurality of cables that may be sequentially attached to each other so as to form a chain of cables. This sequence of cables is made of a starting cable 34 followed by as many extension cables 36 that are required to position the platform 18 at a desired height, as will be explained later. Although being similar in their construction, the starting cable 34 may differ in its length from the extension cables 36 so that the platform may be positioned at the right starting position along the height of the existing building 12. The starting cable 34 is directly attached to the supporting beam 28 of the support structure 14. Again, the starting cable 34 is attached statically to the support structure 14 so that it simply hangs straight down, not being subject to cyclical bending around the drum of a winch, as in some installation of the prior art.

[0049] As shown in Figure 3, now concurrently referred to, both the starting cable 34 and the extension cables 36 are provided with anchoring points 32. The anchoring points 32 are advantageously provided in an anchor plate 38 attached to a lower portion of a cable 39. Each anchor plate 38 preferably comprises a plurality of the anchoring points 32 so as to provide some adjustability when attaching a subsequent extension cable 36. Each cable 34, 36 is assembledaccording to state-of-the-art practices using appropriate hardware. The extension cables 36 are attached at a lower end of a previous extension cable 36 or of the starting cable 34. In particular, the extensions cables 36 are removably attached at one of the anchoring points 32, preferably the lower anchoring point, of the preceding cable using a shackle 40.

[0050] The length of the starting cable 34 is pre-determined so that the platform is vertically positioned so as to comfortably work on a last floor of the building 12, or at a first floor from the top where renovation works need to be performed. The length of the extension cables is determined to match a predetermined integer multiple of number of floors (1 , 2, 3...). If the loads so require, more than one suspension set 16 may be used in parallel for each supporting beam 28.

[0051] In Figure 4, the platform 18 comprises a platform structure 42 and a shell 44. Although the platform 18 is depicted as being custom built to fit around the periphery of the building 12, it does not have to be because of lateral stabilizers installed within.

[0052] The shell 44 comprises a floor 46 and a roof 48 interconnected by a side wall 50. The side wall 50 is placed so as to be distant from the exterior wall 26 of the existing building 12 when the mobile work platform system 10 is installed on the building 12, thereby creating an enclosed workspace 52 for workers. This enclosed worki space 52 is delimited by the floor 46, the side wall 50, the roof 48 and the exterior wall 26 of the existing building 12. The floor 46 may be provided with one or more access hatches 54 to allow receiving materials within the platform 18. Additional internal divisions can be used to divide the enclosed workspace 52 even more if required.

[0053] A roof seal 56 and a floor seal 58 may be used to respectively seal the roof 46 and the floor 48 against the exterior wall 26 so as to isolate the working space 52 from outside elements such as heat, cold, rain, snow, etc. To this extent, the enclosed working space 52 may be heated or cooled with the appropriate heating and cooling equipment so as to provide a comfortable workingenvironment to the workers. The roof seal 56 and the floor seal 58 may take the shape of a flexible lip made of a resilient material, a brush, a foam or an inflatable bladder. The floor seal 58 conveniently also prevents any dropped material or tool from dropping all the way down the building 12. Moreover, as shown in Figure 5 the floor seal 58, as well as the roof seal 56 if so desired, may be designed to absorb energy. For example, a glass panel could be dropped along the exterior wail 26 during refurbishing works and the floor seal 58 could absorb the energy of the glass panel dropping, preventing the glass panel from dropping all the way to the ground and ideally even preventing the glass panel from breaking. The floor seal 58 can be designed with an energy-absorbing surface 57 backed by steel stiffeners 59 that provide sufficient rigidity so that the energy-absorbing surface 57 does not get shattered by a heavy object dropped on the floor seal 58. The energyabsorbing surface 57 can be placed at an angle from the floor 46, such as raising 45 degrees, so that the object dropped on the floor seal 58 would be deflected on the floor 46 of the platform 18. The energy-absorbing surface 57 may be made of a sandwich structure comprising wood or foam inside. It can also be made of a wood panel such as plywood or other material combinations.

[0054] The shell 44 may include partitions to divide the working space 52 in different areas depending on needs. For example, one area used for welding could be divided by a partition wall from another area of the working space 52 where electrical works are conducted or for asbestos removal.

[0055] The side wall 50 is made of polycarbonate panels or other similar materials that may be sufficiently translucent to let sunlight in, but not fully transparent so as to prevent clearly seeing outside. This benefits those workers who are afraid of heights as they do not realize that they are in fact at elevated heights, suspended in the air. It also provides confidentiality for the occupied building floor when the exterior walls are removed or replaced.

[0056] Attached to the platform structure 42 are fixed attachments 60 and translation mechanisms 62, both fixedly attached to a vertical beam 63 using a fixed portion 64 inside the shell 44. One fixed attachment 60, one translationmechanism 62 and one vertical beam 63 are associated and aligned with one suspension set 16 and one support beam 28 fixed at the top of the building 12. Hence, although the present example is singular in order to ease the description, it must be understood that all associated fixed attachments 60, translated mechanisms 62, vertical beam 63, suspension sets 16 and support beams 28 interact exactly the same way.

[0057] The fixed attachments 60 are designed to be fastened to and unfastened from the anchoring points 32 of the associated suspension set 16. The fixed attachment 60 is a clamp having a hole or an opening that is designed to pinch the anchor plate 38, using a bolt or a pin passed through the clamp hole and aligned through one of the anchoring points 32.

[0058] The translation mechanism 62 has the fixed portion 64 and a dynamic end 66. The fixed portion 64 is fixedly connected to the platform structure 42 and therefore only moves with the platform 18. The dynamic end 66 is selectively (e.g. removably / detachably) connectable to one of the anchoring points 32 of the associated suspension set 16 through a dynamic attachment 67. The dynamic attachment 67 is shaped as a clamp, similarly to the design of the fixed attachment 60 and is also designed to be selectively fastened to the anchor plate 38 using a bolt. The dynamic end 66 is provided with a slider 69 for sliding up and down along the vertical beam 63, which acts as a guide for the dynamic end 66.

[0059] The translation mechanism 62 uses an actuator to impart movement to the dynamic end 64. The actuator is fixedly attached to the platform structure 42 at the fixed portion 64. The actuator may be a telescoping hydraulic piston, a linear actuator or any other suitable type of actuator. Preferably, it is electrically powered. The fixed portion 64 is placed above the dynamic end 66 so that in case of failure of the actuator, the dynamic end 66 abuts against the fixed portion 64 and holds the platform 18 in place.

[0060] Lateral stabilizers 68 are used to guide the platform 18 during its vertical displacements along the building 12 so that the platform structure 42 does not contact the exterior wall 26 (other than through the roof and floor seals 56,58and damages it. At least one lateral stabilizer 68 is typically used per side of the building 12. The lateral stabilizer 68 is provided with a sliding end 70 slidingly engaging the vertical beam 63 and a connecting end 72 for fixedly connecting to the existing building 12, in particular for connecting to the building structure 74, such as floors. The sliding end 70 is designed to slide on the vertical beam 63 when the platform moves vertically. The platform 18 is thereby maintained at a predetermined distance from the building 12. The lateral stabilizer 68 is extendable so as to reach the building structure 74 through the exterior wall 26 of the building 12.

[0061] Figures 5 to 12 are now concurrently referred to. A method for providing access to the exterior of the multistory existing building 12 using the mobile work platform system 10, including the vertical displacement of the platform 18 will now be described. Only the downward movement of the platform is described since the steps to create an upward movement are the same steps, simply executed in reverse. The sequence described allows the platform to be vertically moved by a multiple, typically of 1 or 2, floor heights. This may be repeated in order to sequentially cover substantially the whole height of the building 12.

[0062] Figure 6 depicts the platform in a first resting position. Here again, the sequence will only be described with respect to one associated assembly of fixed attachment 60, translation mechanism 62, vertical beam 63, suspension set 16 and support beam 28, but it is understood that the same sequence occurs at all such assemblies. In the position depicted in Figure 6, the fixed attachment 60 is bolted with a bolt 61a at a lower portion of the starting cable 34, that is to its anchor plate 38 so that the platform 16 is secured in place at a first vertical distance from the top 24 of the building. The actuator of the translation mechanism 62 is retracted so that the dynamic end 66 is close to the fixed attachment 60. In this position, the weight of the platform 18 is supported by the starting cable 34 and the actuator of the translation mechanism 62 is unloaded from the weight of the platform 18. At this point, the extension cable 36 does not support the weight of the platform 18.

[0063] Figure 7 depicts the first step in preparation for moving the platform 18. At this stage, the platform 18 is still at the same first vertical distance from the support structure 28 (or from the top 24 of the building 12). The platform 18 is attached to the suspension set 16 through the fixed attachment 60. The translation mechanism 62 is initially not loaded with a weight of the platform 18. During this first preparation step, the translation mechanism 62 is extended downwardly until its dynamic end 66 reaches the lower portion of the extension cable 36, that is until the dynamic end 66 reaches the vicinity of the anchor plate 38 of the extension cable 36. Since the anchor plate 38 is provided with many anchoring points 32, fine tuning of the desired height may be achieved. Then, the clamp of the dynamic end 66 is bolted with another bolt 61b and secured at one of the anchoring points 32. At this point, a load transfer occurs between the fixed attachment 60 and the translation mechanism 62. This may be achieved by slightly extending the translation mechanism 62 to slightly rise the platform 18, thereby releasing the load on the fixed attachment 60 so that the bolt 61a may be undone and detached from the starting cable 34, thereby releasing the fixed attachment 60. This is what is depicted in Figure 8 where, at this stage, the weight of the platform 18 is supported by the translation mechanism 62, through the suspension set 16 which, at this stage, is made of the starting cable 34 and one extension cable 36 and bolted to the dynamic attachment 67 with the bolt 61 b.

[0064] Since the platform 18 is now solely attached to the suspension set 16 through the translation mechanism 62, the dynamic end 66 may gradually be brought closer to the fixed portion 64 of the translation mechanism 62, thereby in fact lowering the platform 18, If an extendable actuator is used, the actuator is gradually retracted at this stage, much as depicted in Figures 9 and 10. In Figure 9, the translation mechanism 62 is partly retracted and the platform 18 is at an intermediate vertical distance. In Figure 10, the translation mechanism 62 is fully retracted and the platform 18 has reached a second resting position. The platform 18 travelled downwardly to a greater distance from the top 24 than it originally was. All through this vertical displacement, only the dynamic end 66 of the translation mechanism 62 is attached to the suspension set 16 to support the platform 18.

[0065] In this transitional position shown in Figure 9, the platform 18 is at an intermediate vertical distance from the support structure 14 that is greater than the first vertical distance where the platform 18 was at the first resting position. The dynamic end 66 of the actuator of the translation mechanism 62 is attached at the lower portion of the associated extension cable 36, the actuator of the translation mechanism 62 supporting the weight of the platform 18, and the lower portion of the extension cable 36 is loaded with the weight of the platform 18. During the platform 18 translation, the lateral stabilizer 68 remains fixedly connected to the building structure 74 at its connecting end 72 and slides on the vertical beam 63 at the sliding end 70.

[0066] The translation mechanism 62 is provided with sensors (load, distance, etc) allowing to individually finely control the movement of each translation mechanism 62 so that a controller can synchronize their movement and keep the platform horizontal. Moreover, the controller can detect whether one translation mechanism 62 has a variation of its loading during vertical displacement, which would be indicative of a problem. Also, the fixed portion 64 of the translation mechanism 62 is intentionally installed above the dynamic end 66 so that in case of failure of the translation mechanism during the vertical displacement of the platform 18, the dynamic end 66 would abut against the fixed portion 64, thereby stopping short an unfortunate drop of the platform 18.

[0067] In Figure 11 , the platform 18 is lowered to the second position at a greater distance from the support structure 14 than it originally was. At this stage, the platform 18 is reattached to the suspension set 16 by clamping the fixed attachment 60 on the anchor plate 38 of the extension cable 36 by using the bolt 61a passed through the fixed attachment 60 and one anchoring point 32. Once the platform 18 is so secured to the suspension set 16, the dynamic end 66 of the translation mechanism 62 may then be detached from the suspension set 16, and more particularly, from the extension cable 36. This is achieved by removing the bolt 61b, thereby releasing from the dynamic attachment 67. This unloads the translation mechanism from the weight of the platform 18. This is depicted in Figure12, where the platform has reached a second resting position and where workers may resume their activities.

[0068] As shown in Figure 13a, the lateral stabilizer 68 is disconnected from the building structure 74 at an upper floor and reconnected to the building structure 74 at a lower floor where the platform is now located so as to be ready for the next downward movement of the platform 18. In Figure 13b, also in preparation for the next vertical translation, a second extension cable 76 is attached to the first extension cable 36. When ready to lower the platform 18 once again, the translation mechanism 62 would be extended so that the dynamic end 66 would be placed in proximity of the lower portion of the second extension cable 76.

[0069] Figure 14 shows an example of engineering detail of the translation mechanism 62 installed on the vertical beam 63 of the platform structure 42 where the fixed attachment 60 - is attached to the anchor plate 38 of the extension cable 36 and the dynamic attachment 67 is free. As can be appreciated, the fixed attachment 60 and the dynamic attachment 67 are similar in their clamp design. The slider 69 is provided at the dynamic end 66 to allow the dynamic end 66 to slide on the vertical beam 63. Figure 14 represents the same platform translation step as the one schematically depicted in Figure 6.

[0070] The present invention has been described with regard to preferred embodiments. The description as much as the drawings were intended to help the understanding of the invention, rather than to limit its scope. It will be apparent to one skilled in the art that various modifications may be made to the invention without departing from the scope of the invention as described herein, and such modifications are intended to be covered by the present description. The invention is defined by the claims that follow.

Claims

WHAT IS CLAIMED IS:1 . A mobile work platform system for providing elevated access to an exterior of a multistory existing building, the mobile work platform system comprising: a support structure having attachment points for attaching to the existing building; a plurality of suspension sets, each suspension set being statically attached at its upper portion to the support structure, each suspension set having sequential anchoring points placed along the suspension set; and a platform, the platform having: a platform structure; fixed attachments for selectively being attached at one of the anchoring points of an associated one of the suspension set so that the platform is suspended from the support structure through the plurality of suspension sets; and translation mechanisms, each translation mechanism having a fixed portion connected to the platform structure and a dynamic end, each translation mechanism being associated with one fixed attachment and with one suspension set, the dynamic end of each translation mechanism being removably connectable to one of the anchoring points of the associated suspension set, wherein during a first platform resting position, the platform is at a first vertical distance from the support structure, the suspension set is attached to the fixed attachments and the translation mechanisms are not loaded with a weight of the platform, and wherein during a first platform displacement, the dynamic end of each translation mechanism is connected at one anchoring point of the associated suspension set, and each fixed attachment is detached from the associated suspension set, the translation mechanisms being operative toretract or to extend so as to move the platform to a second position that is at a different vertical distance from the support structure than the first vertical distance.

2. The mobile work platform system of claim 1 , wherein each suspension set is a cable set comprising a plurality of cables attached sequentially so as to form a chain of cables, each cable having an anchor plate at its lower portion, each anchor plate having a plurality of the anchoring points therein, wherein within each cable set, a first one of the cables is a starting cable connected to the supporting structure and wherein the subsequent cables within each cable set are extension cables.

3. The mobile work platform system of claim 2, wherein each translation mechanism comprises an actuator, the actuator being fixedly attached to the platform structure at the fixed portion, the fixed portion being placed above the dynamic end so that in case of failure of the actuator, the dynamic end abuts against the fixed portion.

4. The mobile work platform system of claim 3, wherein the actuator is operable between a first retracted position, a first extended position, a first transitional position and a second retracted position, wherein in the first retracted position, the platform is at the first vertical distance from the support structure, each fixed attachment is attached at the lower portion of the associated starting cable so that a weight of the platform is supported by the starting cables, and the actuator of each translation mechanisms is unloaded from the weight of the platform; wherein in the first extended position, the platform is at the first vertical distance from the support structure, each fixed attachment is attached at the lower portion of the associated starting cable and the dynamic end of the actuator of each translation mechanism is attached at the lower portion of the respectively associated extension cable, at least one of the actuator and one of the associated extension cable supporting at least partially the weight of the platform;wherein in the first transitional position, the platform is at the first intermediate vertical distance from the support structure greater than the first vertical distance, the dynamic end of the actuator of each translation mechanism is attached at the lower portion of the associated extension cable, the actuator of each translation mechanism supporting at least partially the weight of the platform, and the lower portions of the extension cables are loaded with the weight of the platform; and wherein in the second retracted position, the platform is at the second vertical distance from the support structure larger than the first intermediate distance, each fixed attachment is attached at the lower portion of the associated extension cable, each extension cable at least partially supporting the weight of the platform, and the actuator of each translation mechanism is unloaded from the weight of the platform.

5. The mobile work platform system of claim 3, wherein the platform structure comprises vertical beams, each fixed attachment and each actuator being located on a different one of the vertical beams, the dynamic end of the actuator of each translation mechanism slidingly engaging the vertical beam on which it is located.

6. The mobile work platform system of claim 5, wherein at least one of the translation mechanisms comprises a lateral stabilizer, the lateral stabilizer having a sliding end connected to the vertical beam platform and a connecting end for connecting to the existing building, the sliding end being operative to slide on the vertical beam when the platform transitions from the first vertical distance to the second vertical distance, thereby maintaining the platform at a predetermined distance from the building.

7. The mobile work platform system of claim 1 , wherein the platform further comprises a shell having a floor and a roof interconnected by a side wall, the side wall being placed so as to be distal from the exterior wall of the existing building when the mobile work platform system is installed on the existing building, thereby creating an enclosed interior space for workersdelimited by the floor, the side wall, the roof and the exterior wall of the existing building.

8. The mobile work platform system of claim 7, wherein the platform comprises an access hatch in the floor for allowing access to the platform and inside the shell.

9. The mobile work platform system of claim 7, wherein the platform further comprises a top seal and a bottom seal for sealing against an exterior wall of the existing building, the top seal being located proximate the roof and the bottom seal being located proximate the floor.

10. The mobile work platform system of claim 9, wherein at least one of the top seal and the bottom seal are one of a flexible lip, a brush, a foam, an inflatable bladder and an energy-absorbing structure.

11. The mobile work platform system of claim 1 , wherein the support structure is attached to an upper portion of the existing building.

12. A method for providing access to an exterior of a multistory existing building using the mobile work platform system of claim 2, the method comprising: supporting the platform at the first vertical distance from the support structure by attaching each fixed attachment at the anchoring plate of the first one of the cables so that the weight of the platform is supported by the first cable of each cable set; and retaining the translation mechanisms unloaded from the weight of the platform.

13. The method of claim 12, further comprising: extending each translation mechanism so that the dynamic end reaches the anchor plate of a first one of the extension cable of an associated suspension set while the platform remains at the first vertical distance from the support structure;attaching the dynamic end of each translation mechanism to the anchor plate of the first one of the extension cables of each associated suspension set; disconnecting each fixed attachment from the anchoring plate of the first one of the cables; and supporting the weight of the platform using the translation mechanisms and the first extension cable of each cable sets.

14. The method of claim 13, further comprising: lowering the platform at a first intermediate vertical distance from the support structure that is larger than the first vertical distance; supporting at least part of the weight of the platform with the translation mechanisms; and loading the lower portion of the extension cables with the weight of the platform.

15. The method of claim 14, further comprising: lowering the platform at the second vertical distance from the support structure that is larger than the intermediate vertical distance; attaching each fixed attachment at the lower portion of the associated extension cable; supporting at least partially the weight of the platform with the extension cables; and detaching the dynamic end of the translation mechanisms from the lower portion of the extension cables so as to unload the translation mechanisms from the weight of the platform.

16. The method of claim 15, further comprising connecting an additional extension cable at the lower portion of each cable sets.

17. A method for providing access to different levels of an exterior of a multistory existing building, the method comprising lowering from a first vertical position to a second vertical position a platform attached to a top portion of the existing building through a plurality of static starting cables loaded with a weight of the platform, the platform having a plurality of actuators, each one of the plurality of actuators having a fixed portion and a dynamic end and being associated with at least one of the plurality of starting cables, the lowering having: attaching each one of a plurality of first extension cables at a lower portion of one of the plurality of starting cables associated to one of the plurality of actuators; attaching the dynamic end of each one of the plurality of actuators to a lower portion of the associated one of the plurality of first extension cables; detaching the platform from the lower portions of the each one of the plurality of starting cables; and retracting the plurality of actuators, thereby lowering the platform.

18. The method of claim 17, further comprising attaching the platform at the lower portion of each one of the plurality of first extension cables.

19. The method of claim 18, further comprising detaching the dynamic end of each one of the plurality of actuators from the lower portion of the associated one of the plurality of first extension cables.

20. The method of claim 19, further comprising attaching one of a plurality of second extension cables at the lower portion of each one of the plurality of first extension cables.

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