Scaffolding structure

Abstract

A scaffolding structure for mounting to a supporting structure such as a bridge includes a track fixable to the supporting structure, and a frame. The frame and track are movable relative to one another, and the frame is also movable relative to the supporting structure between a first position and a second position. In the first position, the track supports the frame, and the track is supported by the supporting structure, so that when the track is fixed to the supporting structure, the frame can advance along the track and therefore along the supporting structure. In the second position, the frame is supported by the supporting structure and the track is supported by the frame, so that the track can advance along the supporting structure. By alternately advancing the frame and the track, the scaffolding structure can advance along the entire length of the supporting structure.

1 . A scaffolding apparatus providing access to a structure, comprising: 
 a frame, the frame comprising two side supports and a cross-member connected between the side supports, the frame supporting a worker platorm;    at least one coupling mechanism coupled to each side support for coupling the frame to a supporting structure;    each coupling mechanism including a rail assembly, each rail assembly extending in a longitudinal direction and being selectively securable to the supporting structure, rail assembly having a housing shaped to retain a roller member secured to the frame therewithin and to permit movement of the track and the at least one foot relative to one another in the longitudinal direction of the supporting structure;    an actuator secured to the frame and adapted to selectively move the coupling mechanism between a first position wherein the frame is movable relative to the rail assembly and the supporting structure in the longitudinal direction, and a second position wherein the frame is fixed relative to the supporting structure and the rail assemblies are movable relative to the frame and the supporting structure in the longitudinal direction.    
   
   
       2 . The scaffolding structure of  claim 1 , wherein the first position defines a lowered position in which each rail assembly bears against the support structure, and the weight of the frame bears against each rail assembly, and wherein the second position defines a raised position in which each rail assembly is raised clear of the support structure, and the weight of the frame bears against the support structure.  
   
   
       3 . The scaffolding structure of  claim 2 , wherein each coupling mechanism comprises at least one jack, the jacks adapted to engage the supporting structure and elevate the frame to move the coupling mechanism from the first position to the second position.  
   
   
       4 . The scaffolding structure of  claim 3 , wherein each housing defines a roller retaining channel having a lower channel surface for bearing against the roller member when the coupling mechanism is in the first position.  
   
   
       5 . The scaffolding structure of  claim 4 , wherein each retaining chamber has an upper channel surface for bearing against the roller member when the frame is in the second position.  
   
   
       6 . A scaffolding structure comprising: 
 a frame;    a track, the track being selectively fixable to a supporting structure having a longitudinal direction, the track being movably mountable to the frame;    a mechanism secured to the frame and adapted to selectively move the frame between a first position wherein the frame is movable relative to the track and the supporting structure in the longitudinal direction of the supporting structure, and a second position wherein the frame is fixed relative to the supporting structure and the track is movable relative to the frame and the supporting structure in the longitudinal direction of the supporting structure when not secured thereto.    
   
   
       7 . The scaffolding structure of  claim 6 , wherein the first position is a non-elevated position relative to the supporting structure, and wherein the second position is an elevated position relative to the supporting structure.  
   
   
       8 . The scaffolding structure of  claim 7 , wherein the mechanism comprises a plurality of jacks, and wherein the jacks are adapted to engage the supporting structure and elevate the frame into the second position.  
   
   
       9 . The scaffolding structure of  claim 8 , wherein the frame comprises at least one foot, and wherein the track comprises at least one rail assembly, and wherein each at least one rail assembly comprises a housing shaped to receive and movably retain therewithin a corresponding at least one foot.  
   
   
       10 . The scaffolding structure of  claim 9 , wherein each housing has an interior surface or surfaces, and wherein each at least one foot comprises a member or members for rollably engaging the interior surface or surfaces of the corresponding housing within which the foot is retained.  
   
   
       11 . The scaffolding structure of  claim 10 , wherein each housing has an upper interior surface and a lower interior surface, and wherein each foot comprises a wheel or wheels, and wherein when the frame is in the first position, the wheel or wheels support the frame and are rollably disposed on the lower interior surface of the corresponding housing, and wherein when the frame is in the second position, each at least one rail assembly is supported by its upper interior surface, the upper interior surface resting rollably on the wheel or wheels of the corresponding foot.  
   
   
       12 . A displaceable scaffolding apparatus, comprising: 
 a) a frame supporting a worker platform;    b) a coupling mechanism connected to the frame for coupling the frame to a pair of beams of a structure, the coupling mechanism movable between a first position and a second position;    c) the coupling mechanism including a track fixable relative to the beams and along which the frame can be advanced when the coupling mechanism is in the first position;    d) the frame being fixable relative to the beams for advancing the track relative to the frame when the coupling mechanism is in the second position.    
   
   
       13 . The apparatus of  claim 12  wherein the coupling mechanism comprises actuators for moving the coupling mechanism between the first and second positions, the actuators having a body portion fixed to the frame and an extension portion displaceable relative to the body portion and adapted to engage the beam.  
   
   
       14 . The apparatus of  claim 13  wherein the track is raised clear of the beam when the coupling mechanism is in the second position.  
   
   
       15 . The apparatus of  claim 14  wherein the coupling mechanism comprises a plurality of rollers rotatable about a roller axis, the roller axis being fixed relative to the frame, and the rollers being coupled to the track.  
   
   
       16 . The apparatus of  claim 15  wherein the track comprises rail elements having a roller retaining channel along which the rollers travel for coupling the frame to the track, the roller retaining channel having a channel height that extends between a lower channel surface and an upper channel surface.  
   
   
       17 . The apparatus of  claim 16  wherein the channel height is greater than the roller diameter by an amount defining a channel clearance, and wherein the rollers engage the lower channel surface when the coupling mechanism is in the first position, and engage the upper channel surface when the coupling mechanism is in the second position.  
   
   
       18 . The apparatus of  claim 17  wherein the total displacement of the extension portion when moving the coupling mechanism between the first and second positions is greater than channel clearance.  
   
   
       19 . A method of providing worker access to a structure having beams, comprising: 
 a) providing a scaffold apparatus having a frame supporting a worker platform and a coupling mechanism for coupling the frame to the beam, the coupling mechanism including a track displaceable relative to the frame;    b) fixing the track to the beam along a first selected beam segment;    c) advancing the frame along the track to adjust the position of the platform to facilitate worker access to parts of the structure generally aligned with the selected beam segment;    d) fixing the frame to the beam with the track clear of the beam;    e) advancing the track relative to the beam to a second selected beam segment adjacent the first selected beam segment; and    f) repeating step c) for the second selected beam segment.    
   
   
       20 . The method of  claim 19  wherein the coupling mechanism includes actuators movable between advanced and retracted positions, and wherein step d) includes moving the actuator to the advanced position.