Abstract
A method of stabilizing a suspended scaffolding system against a main stable structure by using the intentional displacement of the centre of gravity of the suspended scaffold off its equilibrium position and preventing the return of the centre of gravity to the equilibrium free-hanging state. The displacement of the centre of gravity is to be achieved by movement of the counterweight of the suspended scaffolding. The centre of gravity is prevented from returning to the equilibrium position by using adjustable bumpers between the suspended scaffolding system and the main stable structure. A restoring gravity force induced by the displacement of the centre of gravity off the equilibrium position acts as a pushing force to provide firm stabilization of the suspended scaffolding against the main stable structure.
Claims
1. A method for stabilizing a suspended scaffolding system against a structure, the method comprising: coupling an attachment system to a surface of the structure; mounting a suspended working platform having a counterweight to the attachment system such that the counterweight is movable between a first position and a second position; moving the counterweight from the first position in which a center of gravity of the scaffolding system is positioned in a vertical plane of the attachment system and the scaffolding system is in an equilibrium state to the second position in which the center of gravity of the scaffolding system is displaced away from the vertical plane of the attachment system and the scaffolding system is in a nonequilibrium state; and securing the counterweight in the second position while preventing a return of the suspended working platform center of gravity to the first position in the vertical plane of the attachment system by using an adjustable bumper between the suspended working platform and the structure; and stabilizing the suspended working platform against the structure by maintaining the center of gravity being not in the vertical plane of the attachment system and utilizing a restoring gravity force to push the suspended working platform towards the structure.
2. The scaffolding system of claim 1, wherein the counterweight is movable from the first position to the second position by at least one of a manual displacement method and a mechanical displacement method.
3. The scaffolding system of claim 2, wherein the mechanical displacement method is operated via a remote control.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The invention will now be described, by way of example, with reference to the accompanying drawings: in which:—
(2) FIGS. 1A-1B show a diagram of the technical stabilizing device (FIG. 1A) and main acting forces scheme (FIG. 1B) showing a suspended object in free hanging and moveable position, for the option of upper surface fixing to the main structure;
(3) FIGS. 2A-2B show a diagram of the technical stabilizing device (FIG. 2A) and main acting forces scheme (FIG. 2B) showing a suspended object in working position, for the option of upper surface fixing to the main structure;
(4) FIGS. 3A-3B show a diagram of the technical stabilizing device (FIG. 3A) and main acting forces scheme (FIG. 3B) showing a suspended object in free hanging and moveable position, for the option of underside surface fixing to the main structure;
(5) FIGS. 4A-4B show a diagram of the technical stabilizing device (FIG. 4A) and main acting forces scheme (FIG. 4B) showing a suspended object in working position, for the option of underside surface fixing to the main structure;
(6) FIGS. 5A-5B show a diagram of the technical stabilizing device (FIG. 5A) and main acting forces scheme (FIG. 5B) showing a suspended object in free hanging and moveable position, for the option of side surface fixing to the main structure;
(7) FIGS. 6A-6B show a diagram of the technical stabilizing device (FIG. 6A) and main acting forces scheme (FIG. 6B) showing a suspended object in working position, for the option of side surface fixing to the main structure;
(8) FIGS. 7A-7B show a diagram of the technical stabilizing device (FIG. 7A) and main acting forces scheme (FIG. 7B) showing a suspended object in free hanging and moveable position, for the option of slot upper surface fixing to the main structure;
(9) FIGS. 8A-8B show a diagram of the technical stabilizing device (FIG. 8A) and main acting forces scheme (FIG. 8B) showing a suspended object in working position, for the option of slot upper surface fixing to the main structure;
(10) FIGS. 9A-9B show a diagram of the technical stabilizing device (FIG. 9A) and main acting forces scheme (FIG. 9B) showing a suspended object in free hanging and moveable position, for the option of underside internal surface fixing to the main structure;
(11) FIGS. 10A-10B show a diagram of the technical stabilizing device (FIG. 10A) and main acting forces scheme (FIG. 10B) showing a suspended object in working position—stabilized according to the invention, for the option of underside internal surface fixing to the main structure;
(12) FIG. 11 is a perspective of a frame (SWP— Suspended Working Platform) for a suspended scaffolding system according to the invention;
(13) FIGS. 12A-12B show a perspective of an attachment system for attaching a frame (SWP™—Suspended Working Platform) to a rail;
(14) FIGS. 13A-13B show a perspective of a counterweight system according to the invention;
(15) FIG. 14 is a perspective of a counterweight system in free hanging position;
(16) FIGS. 15A-15B show a cross section through a rail and carriage truck;
(17) FIG. 16 is a perspective of a suspended scaffolding system according to the invention (with standard scaffolding system infill used to create safe working environment);
(18) FIG. 17 is an alternate perspective view of a suspended scaffolding system;
(19) FIG. 18 is a transverse view of a suspended scaffolding system;
(20) FIG. 19 is a transverse view of a suspended scaffolding system in free hanging position; and
(21) FIG. 20 is a transverse view of a suspended scaffolding system in fixed or working position.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
(22) FIGS. 1A-10B illustrate some general usage scenarios of a device according to the invention providing suspended objects stabilization by pushing them to main stable structure 30 by using force from moving the suspended object's centre of gravity 38 away from its neutral position. The centre of gravity 38 movement is caused by position adjustment of counterweight 37 component of the device.
(23) Each of FIGS. 1A-10B show (in different configurations, mounting and usage scenarios) the same elements of the invented stabilization method: the structure 30 (building, bridge, slab, and terrace, ship . . . ) to be accessed for carrying the work from beneath 2a: structure 30. There are three main parts, the attachment system 31,32,33 of the suspended object/scaffolding which is the connection to the structure 30, a suspended object/suspended working platform 34,35,36,37,39; and additional features such as scaffolding 40, 41, 42.
(24) The attachment system 31,32,33 comprises a fixture including one or more fixing points or a rail 31, temporarily or permanently fastened to the structure 30.
(25) For applications in which the suspended object is movable along the length of the structure, a rail 31 is provided for attachment to the structure 30 and one, two or more independent carriage/truck sets 32 are provided which roll within the rail 31 connected via a pin mounted in a bearing 33 at the end of the suspended object/suspended working platform beam or arm 34,39.
(26) The fixing system includes a spherical bearing 33 or Cardan mount or any other bearing solution allowing rotation in any plane. The suspended object/suspended working platform frame is represented here by the suspended object/suspended working platform beam or arm 39 (FIGS. 1A-1B and 2A-2B only), vertical mounted down arm/frame 34, and a horizontal working part of the platform 35, with adjustable (angle and length) bumpers/buffers end 36. The use of the platform 35 as a working environment would require optional add-in for example: allowing access horizontal platform 40—any scaffolding system or other, scaffolding stair tower access 41—any scaffolding system or other, lower working level horizontal platform 42 with side bars—any scaffolding or formwork system.
(27) The whole suspended object/suspended working platform 34,35,36,37,39 in a free hanging position (FIGS. 1A-1B, 3A-3B, 5A-5B, 7A-7B, and 9A-9B) is hanging freely on two or only one support points 31 vulnerable for example for the wind pressure, not stabilized, even free swinging, with the possibility of hitting the structure 30 if prevention measures are not taken against that (i.e. Dumpers can be used to reduce swinging caused by wind).
(28) In examples where the support points 31 are provided on a rail, in this configuration—hanging freely—the suspended object is easily movable along the length of the structure and can pass obstacles.
(29) The suspended working platform 34,35,36,37,39 comprises suspended object/suspended working platform beam or arm 39 through which the suspended object is attached to the structure 30, vertical side frames 34, a horizontal frame of working platform 35 and bumpers/buffers 36 for abutment to the underside 29 of the structure 30. The angle and length of the bumpers and buffers 36 are adjustable according to need. In the free hanging position (FIGS. 1A-1B, 3A-3B, 5A-5B, 7A-7B, and 9A-9B) there is no contact of bumpers/buffers 36 with the main structure 30.
(30) The stabilization effect of the free hanging object to the main outer structure 30 is achieved by adding a counterweight 37, to the suspended object/scaffolding, and adjusting this counterweight's position. The counterweight can be moved and locked in different positions in relation to the suspended object/scaffolding, for example by the use of rails and hydraulic jack).
(31) When the centre of gravity 38 of the whole hanging structure (suspended working platform 34,35,36,39 and counterweight 37 and possibly workers, equipment and materials as well as add-on accessories) is in a neutral position, it lies within a strictly vertical plane B below the upper attachment point/points 31, then the whole structure is hanging freely—like the scheme pictured on FIGS. 1A-1B, 3A-3B, 5A-5B, 7A-7B, and 9A-9B.
(32) When the counterweight part 37 of the whole suspended working platform 34,35,36,39 is intentionally repositioned in direction C opposite the main outer structure location 30 i.e. away from the centre of the structure 30 or towards an outer edge of the structure 30, then the centre of gravity 38 of the whole structure (suspended working platform 34,35,36,39 and counterweight 37 and possible workers, equipment and materials as well as add-on accessories) is moved off its neutral position—like the schemes pictured in FIGS. 2A-2B, 4A-4B, 6A-6B, 8A-8B, and 10A-10B.
(33) In this position, the main acting force—the gravity, is forcing the shifted centre of gravity 38 back towards neutral position which is exactly within a strictly vertical plane below the upper attachment point/points 31. However, this movement is prevented by the bumpers/buffers, that indicated force F3 is then transferred into the structure 30 via bumpers/buffers 36, and the passive resistance of the structure 30 gives the stability to the whole equipment. The suspended object/suspended working platform remains then in the stabilized, locked-in, working position, as pictured in FIGS. 2A-2B, 4A-4B, 6A-6B, 8A-8B, and 10A-10B.
(34) Note: the forces diagrams of FIGS. 1B, 2B, 3B, 4B, 5B, 6B, 7B, 8B, 9B, and 10B, show only main vertical forces acting F1, F2, F3, and F4 on the components; where F1 force is a vertical component of reaction force on the main structure 30 in the place of upper supporting/fixing point/points or rail; F2 force is a gravity force of the whole suspended object; F3 force and/or F4 force is/are present only for locked-in stabilized position (FIGS. 2A-2B, 4A-4B, 6A-6B, 8A-8B, and 10A-10B), as a vertical component or reaction force, when the suspended object/suspended working platform 34,35,36 is locked in working position by counterweight 37 displacement and passive resistance on the base structure 30 provides a brace.
(35) In the free hanging position of the suspended object (FIGS. 1A-1B, 3A-3B, 5A-5B, 7A-7B, and 9A-9B) the F2 acting gravity force is lined up with the F1 re-acting force of the supporting main structure 30, and the system is in equilibrium. In the locked-in stabilized position (FIGS. 2A-2B, 4A-4B, 6A-6B, 8A-8B, and 10A-10B) the F2 acting gravity force is displaced from the line of the F1 re-acting force of the supporting main structure 30, and the system has a horizontal component reaction force forcing the shifted centre of gravity 38 towards it neutral position strictly under the attachment point/points 31 to the main structure 30. The other component forces (horizontal) would be: wind pressure and horizontal component force of F3 reaction, as the bumper 36 pushes on the angled surface of main structure 30. All horizontal forces would be transmitted onto the structure 30 via the attachment system 31,32,33 and bumpers 36.
(36) FIGS. 1A-1B, 3A-3B, and 5A-5B show the diagrams of the technical stabilizing device and main vertical components of acting forces F1, F2 scheme showing suspended object (example: Suspended Working Platform—SWP) 34,35,36,39 in free hanging and moveable/passable position, respectively for the options of upper, underside and side surface fixing to the main structure 30. In the free hanging position of the suspended working platform 34,35,36,39 the counterweight 37 is used as a member to balance required geometry of the whole equipment (for example when in the process of moving from one to the other work location along the structure). The counterweight 37 position is to be adjusted manually or mechanically, operated from the working platform 35 or elsewhere by remote control.
(37) FIGS. 2A-2B, 4A-4B, and 6A-6B show the diagrams of the technical stabilizing device and main vertical components of acting forces F1, F2, F3 scheme showing suspended object (example: Suspended Working Platform—SWP) 34,35,36,39 in stabilized, locked-in for work position, respectively for the options of upper, underside and side surface fixing to the main structure. In the locked-in, secured and stabilized working position of suspended working platform 34,35,36,39 the counterweight 37 is acting as a member generating the pushing/locking force, bracing the suspended object 34,35,36,39 to the main structure 30. The repositioned and lockable counterweight 37 shifts the centre of gravity off its neutral position and acts here as the member generating the pushing/locking force on one or two bumpers ends 36 from the re-action of the structure 30, providing the required safe and stable working environment.
(38) FIGS. 7A-7B and 8A-8B show the diagrams of the technical stabilizing device and main vertical components of acting forces F1, F2, F3, F4 scheme; showing suspended object (example: Suspended Working Platform—SWP) 34,35,36 respectively in free hanging, moveable/passable position (FIGS. 7A-7B) and working position (FIGS. 8A-8B) for the option of in-slot, upper surface fixing to the main structure 30, when the suspended working platform 34,35,36 is beneath the twin/mirrored main structures 30 or beneath the main structure 30 with a slot, and the suspended working platform 34,35,36 is cantilevered, serving both sides underneath the structures 30; The counterweight 37 is acting here as a balance stabilizer for the total weight of workers, the suspended working platform, materials and equipment, and (using counterweight 37 adjustable position) as the member generating the pushing/locking force on one of two bumpers ends 36 from the re-action of the structure 30, providing the required safe and stable working environment.
(39) FIGS. 9A-9B and 10A-10B show the diagrams of the technical stabilizing device and main vertical components of acting forces F1, F2, F3, F4 scheme; showing suspended object (example: Suspended Working Platform—SWP) 34,35,36 respectively in free hanging, moveable/passable position (FIGS. 9A-9B) and working position (FIGS. 10A-10B) for the option of internal underside surface fixing to the main structure 30 (for example bridge of this specific geometry cross section, or cave), when the suspended working platform 34,35,36 is beneath the main structure 30, and the suspended working platform 34,35,36 is cantilevered, serving both sides underneath the structure 30; The counterweight 37 is acting here as a balance stabilizer for the total weight of workers, the suspended working platform, materials and equipment, and (using counterweight 37 adjustable position) as the member generating the pushing/locking force on one of two bumpers ends 36 from the re-action of the structure 30, providing the required safe and stable working environment. When the working platform is in the free hanging position (not stabilized, locked-in) the counterweight should be placed in such equilibrium position that neither of bumper ends 36 should be in contact with the structure.
(40) FIGS. 11-20 show various aspects of an embodiment of this invention: the SWP™—Suspended Working Platform forming part of the SSS™—Suspended Scaffolding System.
(41) FIG. 11 shows a frame 110,111 for a suspended working platform 100 of suspended scaffolding system and a rail or track 120 onto which the frame 110,111 is mounted.
(42) The rail 120 is secured to a structure 30, such as a bridge, using spaced apart distance supporting pads 126 (see FIG. 18) underneath the rail 120 and rail fasteners/clamps 122 which can bridge over the rail 120 if needed. The rail 120 has a guideway 124 running longitudinally along its' length into which a carriage/truck 112 is located. The carriage/truck 112 has wheels which are adapted to run along the rail 120, within the guideway 124. The carriage/truck 112 is connected to a pivotable arm 114 of the frame 110,111 and is moveable along the rail 120 until it intersects with a fastener 122. The rail 120 is positioned such that the guideway 124 is substantially aligned with the span of the structure 30 Le. along the longitudinal axis A-A of the structure.
(43) The suspended working platform—SWP 100 includes frame having a base portion 111 and two side portions 110 which are disposed on opposite sides 110′,110″ of the base portion 111. At the distal end of each of the side portions 110 a pivotable arm 114 is provided. The frame base 111 is, in use, partially suspended beneath a structure 30 via the frame sides 110 and the pivotable arms 114.
(44) The base 111 includes a counterweight system 140 which comprises a counterweight 142 which is moveable between working positions as shown and a non-working or passable position (see FIGS. 19 and 20 for more information). The counterweight 142 moves along a pair of counterweight rails 144 using a counterweight carriage 148. The movement of the counterweight 142 is facilitated in this example using a hydraulic jack 152 powered by a motor (not shown).
(45) FIGS. 12A-12B show a perspective of an attachment system for attaching a pivotable arm 114 of the SWP—Suspended Working Platform frame 110,111 to a rail 120.
(46) The pivotable arm 114 includes an aperture 218 in which a spherical bearing 118 is housed. The carriage/truck 112 has two vertically disposed extensions 212 in between which the pivotable arm 114 is located. The extensions 212 each have an aperture (not shown) which align with each other and the aperture 218 of the pivotable arm 114 enabling a pin 214 or other fastener to secure the pivotable arm 114 to the carriage/truck 112 via the spherical bearing 118. When the carriage/truck 112 is moved along the rail, the pivotable arm 114 and thus the frame 110, 111 is moved along the rail.
(47) FIGS. 13A-13B show a perspective of a counterweight stabilizing device 140 according to the invention. A pair of counterweight rails 144 is disposed between the side portions of the frame 111 substantially parallel to the sides 110′,110″ (see FIG. 11) of the base of the frame 111.
(48) The counterweight 142 is attached to counterweight carriage 148. The counterweight carriage 148 has wheels 248 which are adapted to run along the counterweight rail 144. A counterweight stabilizer 150 is introduced to stabilize counterweight from swinging. A counterweight shield 146 covers the counterweight rail 144 and the wheels 248 of the counterweight carriage 148 protecting them from damage and ingress of dirt etc. . . .
(49) A hydraulic jack 152 is connected to either the counterweight 142, via mounted plate 154, or to the counterweight stabilizer 150 and when actuated, the jack 152 moves the counterweight 142 linearly along the path of the counterweight rails 144. Movement of the counterweight 142 is generally perpendicular to the longitudinal axis A-A of the structure 30 and this movement causes pivoting of the frame 110, 111 with respect to the structure 30 about rotational direction B-B between a free hanging and a working position when the frame 110,111 is stabilized to the structure 30.
(50) FIG. 14 is a perspective of a counterweight system 140 in free hanging position. The counterweight 142 is located within the internal space 310 of the frame base 111 i.e. the counterweight 142 is located underneath the frame base 111.
(51) FIGS. 15A-15B show a cross-section through a rail 120 and carriage/truck 112. The carriage/truck 112 has pairs of wheels 128 on each side of a central portion 212. The rail 120 comprises an overhang 220 on each side which forms the rail guide 124 and the overhang 220 prevents the carriage/truck 120 from being removed from the rail 120. The carriage/truck 112 may be a lubricated to assist in the movement along the rail 120.
(52) FIGS. 16 and 17 show different perspective views of a suspended scaffolding system 350 and FIG. 18 is a transverse view of the suspended scaffolding system 350 with standard scaffolding infill (PERI in this case). The frame 110,111 is a suspended working platform and a scaffold 370 (any standard system type infill scaffolding) is erected within the frame 110,111 providing a safe access and working environment for construction, inspection and maintenance work.
(53) An upper platform 374 provides access from the structure 30 to a first ladder 378. In this example, an intermediate platform 376 is provided at the bottom of the first ladder 378 with access to a second ladder 380 which leads to the working platform 372. A skilled person will understand how many, if any, intermediate platforms are required.
(54) The scaffold 370 is an infill, of suspended scaffolding system and its suspended working platform and can be any required system scaffolding for example PERI, but any appropriate scaffolding system can be used. The scaffold infill 370 creates a wall 382 around the perimeter of the frame base 111 and a tower 384 around the access point and !adders 378,380. At the corners 388 of the frame base 111 distal to the frame sides 110 i.e. the corners of the frame base 111 which are underneath the structure 30, the corner upright 392 of the scaffold wall 382 extends beyond the wall height ending in an abutment bumper or buffer 390. When the counterweight 142 is in its' working position, as shown, the abutment bumper 390 abuts the underside of the structure 30. The abutment bumper is an integrated part of this invented device, not the standard scaffolding infill.
(55) The frame sides 110 are each connected to a carriage/truck 112 which can be moved along rail 120 which is connected to a structure 30 using spaced apart distance supporting pads 126 between the rail 120 and the structure 30 and rail fasteners 122 which bridge over the rail 120.
(56) The rail fasteners 122 are spaced apart by a nominal distance of around 200 cm however this can be smaller or larger depending on the structure 30. The rail fasteners 122 fix the rail 120 and in addition act as a stop/obstruction for the scaffolding system 350 movements. In order to move the scaffolding system 350 further along the structure, a rail fastener 122 must be temporarily doubled (one in front of, the other behind the carriage to be moved) to allow one fastener to be removed or pivoted away from the rail 120. It is preferred that the distance and multiples of the distance between rail fasteners 122 is not the same as the distance between the two frame sides 111 so only one fastener 122 is removed or displaced at a time to allow passage of the scaffolding.
(57) In this example, in order to move the scaffolding system 350 further along the structure, a rail support 122 must be removed or pivoted away from the rail 120. Again, it is preferred that the distance and multiples of the distance between rail fasteners 122 is not the same as the distance between the two frame sides 111 so only one fastener 122 is removed or displaced at a time to allow passage of the scaffolding.
(58) FIGS. 19 and 20 are cross sections through a suspended scaffolding system in free hanging position and working position respectively. Referring to FIG. 19, the scaffolding system 350 is in its' free hanging or first position with the counterweight 142 located beneath the frame base 111 and the abutment bumper 390 not in contact with the underside of the structure 30. In this configuration, the scaffolding system 350 may be moved along the rail 120 enabling work, inspection or maintenance of a new section of the structure 30.
(59) FIG. 20 shows the scaffolding system 350 in a fixed or working or second position. The counterweight 142 has been displaced or moved lineally using the jack 152 towards the edge of the structure 30 and the frame sides 110 shifting the centre of gravity of the scaffolding system 350 and causing it to rotate in rotational direction B-B (see FIG. 11) via the pivoting arms 114 and forcing the abutment bumper 390 into contact with the underside of the structure 30. In other words, the counterweight 142 is moved away from the structure 30 to produce the force that pushes the suspended scaffolding towards the main stable structure. This creates a stabilizing force or brace for the scaffolding system 350 enabling work to be carried out safely, without the working platform experiencing dangerous uncontrollable swings or movement
(60) Some or all of the scaffolding system 350 may be removed from a structure 30 when not in use as the scaffolding 370 is easy to dismantle and transport, the frame sides 110 could be unbolted from the frame base 111 and the rail 120 removed. Alternatively, the scaffolding system 350 is left attached to a structure 30.
(61) The hydraulic jack may be supplemented by a hand crank in case of failure or replaced by a hand crank or alternative movement options.
(62) In the examples shown and described herein, the rail or track 120 is shown as being located on the upper surface of the structure 30 (see FIGS. 1A-1B, 2A-2B, 7A-7B, and 8A-8B) however the rail may be located on the roadway surface, on a side (see FIGS. 5A-5B and 6A-6B) or underside surface (see FIGS. 3A-3B, 4A-4B, 9A-9B, and 10A-10B) of the structure; the position chosen will depend in part on the design of the structure and the manner of access to the site and the suspended working platform of suspended scaffolding system.
(63) One use of the suspended working platform 100 is to provide under bridge access for carrying the construction, maintenance or inspection work to the lower and side surface of the structure 30. The suspended working platform 100 is delivered on the required work site in parts (dismantled or folded), then the main frame (side frames 110 and horizontal working platform 111) and other structural parts of S\NP are assembled together and attached to the supporting fixing points or rail 120 (by crane for example from below, or from above; by chopper; by sea ship crane)” Then the whole optional add-on accessory (372,374,376,378,380,382,384,390 FIGS. 16, 17), machines, formwork and materials would be placed as required. The SWP allows economical assembling, disassembling and transportation. Compared with the case of building up scaffolding to carry out the construction or maintenance, work efficiency is high, and cost can be considerably reduced. The members of the SWP are designed to be easily connected together for on-site completion, or can be pre-assembled and shipped complete to the job site.
(64) SWP frame 100 has adjustable geometry and structure according to particular case and purposed use and is erected to the geometrical form of the structure 30. The dimensions and geometry of the SSS— Suspended Scaffolding System equipment varies in each particular case of use, adjusted to specific needs, the geometry of the structure to be work subject and the specific requirements of the work type to be carried out, for example:
(65) For light maintenance jobs the working platform would be relatively long, as the work progress is quick, and used equipment is light (i.e. painting, cleaning . . . )
(66) For the work to be carried in one particular place, the working platform would be relatively short (i.e. stressing . . . ) For formwork job type the working platform would be deep and high to cover the work area and carry the formwork equipment
(67) It is to be appreciated that these Figures are for illustration purposes only and other configurations are possible.
(68) The invention has been described by way of several embodiments, with modifications and alternatives, but having read and understood this description further embodiments and modifications will be apparent to those skilled in the art. All such embodiments and modifications are intended to fall within the scope of the present invention as defined in the accompanying claims.
