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You are an expert at summarizing long articles. Proceed to summarize the following text: 
FIELD OF THE INVENTION 
     The present invention generally relates to safety equipment, and more particularly to a tethering and anchoring apparatus to secure workers when working near the edge of a balcony. 
     BACKGROUND 
     High-rise apartment buildings often have balconies surrounded by glass barriers. Though a building may employ rooftop-anchored window washers to clean such exterior glass, such a service is costly, and typically only occurs a few times a year. 
     If an individual tenant wishes to clean the glass surrounding their own balcony at any other time, it is typically their own responsibility to do so. It would generally be too costly to hire a roof-top-anchored window washer to wash the glass for a single unit, so contractors or tenants typically just lean over the edge of the balcony to clean the glass manually, which poses a severe fall risk. 
     Besides being dangerous or fatal, leaning over to wash the glass of a single unit also typically results in significant amounts of dirty or soapy water soiling the glass of balconies situated below the balcony being washed. Although conventional roof-top-anchored window washing is effective, it is not always practical or cost efficient for single-unit needs, and improvement is needed. 
     SUMMARY 
     This and other objects, features, and advantages in accordance with the present invention are provided by a portable folding support structure for safely tethering an individual. In one embodiment, a portable cart has wheels and a motor that actuates at least one of the wheels. The cart is of a size and dimension to fit through a residential doorway when in a folded state. A hand-operated throttle controls the motor, while a hand-operated steering device is used to control the direction of cart travel. 
     An anchoring plate is extendable from the cart to contact a surface below the cart to lift the cart to prevent the cart from unwanted rolling. A substantially horizontal jib with the cart has a harness point capable of receiving a safety cable to which a worker may be attached. 
     A first foldable outrigger projecting from the cart provides additional stability to the cart when the outrigger is in the unfolded position. An anchoring pad attached to a distal region of the first foldable outrigger also promotes stability of the cart. 
     In a related embodiment, a first extension arm is connected to the first foldable outrigger. The first extension arm has an ascending portion and a substantially vertical descending portion. 
     Additionally, a second foldable outrigger projects from the cart to provide stability to the cart, and a second extension arm is connected to the second foldable outrigger. The second extension arm also has an ascending portion and a substantially vertical descending portion. 
     A textile, liquid-absorbing, surface has a first end, a second end, an inner edge and an outer edge. The first end is attached proximate the descending portion of the first extension arm and the second end is attached proximate the descending portion of the second extension arm. The liquid-absorbing surface is positionable about an outer surface of a glass balcony wall such that the inner edge contacts the glass balcony wall and the outer edge projects outwardly from the glass balcony wall to inhibit liquids used to clean the glass balcony wall from spilling below the level of the liquid-absorbing surface. In yet another related embodiment, the cart comprises means to raise and lower the first and second extension arms. 
     The invention also contemplates a method of maintaining an exterior surface of a building. An embodiment of this method comprises the steps of: positioning a cart proximate the exterior surface of a building in need of cleaning, the cart having a sufficient mass to counterweight a person suspended therefrom; unfolding an outrigger to stabilize the cart; securing the outrigger in an unfolded position; providing a jib having a harness point, the jib being attached to the cart; and attaching a line to the harness point; and attaching the line to a person to provide an anchor so that the person may lean over a balcony guardrail. 
     Additional advantages, aspects, and embodiments of the invention are described in the appended Drawings and Detailed Description of the Preferred Embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the invention, reference is made to the following detailed description, taken in connection with the accompanying drawings illustrating various embodiments of the present invention, in which: 
         FIG. 1  illustrates an embodiment of a support structure; 
         FIG. 2  is a side view of the support structure of  FIG. 1 ; 
         FIG. 3  illustrates the support structure of  FIGS. 1-2  in a folded state; 
         FIG. 4  illustrates the support structure of  FIGS. 1-3 , noting how the structure unfolds; and 
         FIG. 5  illustrates the support structure of  FIGS. 1-4  in a used state. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the Summary of the Invention above and in the Detailed Description of the Invention and in the accompanying drawings, reference is made to particular features (including method steps) of the invention. It is to be understood that the disclosure of the invention in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or embodiment of the invention, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects and embodiments of the invention, and in the invention generally. 
     The term “comprises” is used herein to mean that other ingredients, elements, steps, etc. are optionally present. When reference is made herein to a method comprising two or more defined steps, the steps can be carried in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more steps which are carried out before any of the defined steps, between two of the defined steps, or after all of the defined steps (except where the context excludes that possibility). 
     In this section, the present invention will be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the invention to those skilled in the art. 
     Referring initially to  FIG. 1 , a portable folding support structure provides the requisite ballast and support to safely tether a worker so that he may safely lean over a balcony to clean glass or perform maintenance. A preferred embodiment of the support structure is a cart  10 . The cart  10  has a base  12  that provides a platform to which wheels  14  are mounted. The base  12  is preferably rectangular or square, but can be any contemplated shape. The base  12  is a size that allows the cart  10  to fit through a residential doorway. The base  12  is preferably made of metal, such as steel for example, due to strength, the ability to weld other structures of the cart  10  to the base  12 , and for added weight that provides the additional ballast for the support structure to optimally function. Other materials, such as wood, plastics, composites, and other engineered materials are also contemplated. 
     A drive wheel  16  is attached to propulsion means  18 . The propulsion means  18  is preferably an electric motor, but an internal combustion engine is also contemplated. The electric motor is preferably powered by on-board batteries, but an external AC electricity source is also contemplated. In one especially preferred embodiment, external AC electricity is used to charge and recharge batteries that power the electric motor, yet the AC source also provides power to the motor when the cart  10  is plugged in to the AC source. 
     As depicted in  FIGS. 1 and 2 , a control panel  20  provides an interface between a user and the cart  10 . Controls  22  on the control panel  20  are used by the user to control the motion of the cart  10 . In one embodiment, handlebars  24  are used to steer the cart  10 , and also act as a turn throttle to control the speed of the motor. The controls  22  and handlebars  24  are preferably operated by a user&#39;s hands, and are thus situated at approximately hand level for a user of average height. 
     Turning again to  FIG. 1 , the cart  10  also has an anchoring plate  26  that is deployed below the cart. The anchoring plate  26  is an extendable brace that is lowered onto the floor below the cart  10  to lift the cart  10  sufficiently to prevent the cart  10  from rolling for the purpose of stabilization. The anchoring plate  26  remains in an unextended configuration when not in use. When a user desires to stabilize the cart  10 , the user extends the anchoring plate  26  away from the cart  10  to contact the ground, and this is done through a mechanical linkage. In a preferred embodiment, the mechanical linkage is an automatic screw jack, scissor jack, or hydraulic jack positioned between the anchoring plate  26  and the base  12 . The control panel  20  also has appropriate controls  22  to raise and lower the anchoring plate  26 . For example, a screw jack has a motor that actuates a threaded rod integral to such a jack, and the motor is activated by related controls  22 . Similarly, for example, a hydraulic pump is activated by the controls  22  to extend or retract a hydraulic jack connected to the anchoring plate  26 .  FIG. 4  illustrates a motion path (MP) the anchoring plate  26  travels to go from the extended to contracted position. 
     With continuing reference to  FIGS. 1 and 2 , a jib  28  extends from the cart  10 . The jib  28  is a rigid member that is secured in a desired position with a mechanical securing device. In a preferred embodiment, holes  30  defined by the jib  28  receive a clevis pin  32  to secure the jib  28  in a configuration desired by the user. This provides the user with the ability to extend the jib  28  to protrude from the cart  10  a desired length. In one embodiment, the jib  28  is attached to a mast  34 , and preferably at a joint that pivots, yet can be secured to prevent pivoting should a user desire. The jib  28  has a harness point  36  on its end for receiving a safety cable. 
       FIGS. 1 and 2  illustrate outriggers  38  that pivotingly extend away from the cart  10  to engage a surface upon which the cart  10  is situated. The outriggers  38  create a wide footprint and a more stable support structure for safely tethering a user. Between one and six outriggers  38  are used to provide stability with the preferred number of outriggers  38  being four. 
       FIG. 3  illustrates the outriggers  38  in a folded configuration. This is the configuration the cart  10  would take to navigate through doorways.  FIG. 4  indicates the path (P) that the outriggers  38  take to go from the folded position to the extended position. Once in the extended position, the outrigger  38  is lockable in that position. In a preferred embodiment, the outrigger is locked with cotter pins  40  that engage both the outrigger  38  and a securing point  42  ( FIG. 3 ) with the cart  10 , however any conventional locking mechanism is contemplated. 
       FIGS. 1-4  illustrate anchoring pads  44  that attach to the outriggers  38 . The anchoring pads  44  are removably attached a distal region  46  of the outriggers when in the extended position. The anchoring pads  44  provide a relatively large footprint for the cart  10  that results in greater stability. The anchoring pads  44  also provide additional ballast. The anchoring pads are made of a relatively heavy material such as metal, concrete, and combinations thereof. In  FIG. 3 , the anchoring pads  44  are placed upon the base  12  when not in use and the outriggers  38  are in the folded position. 
     Returning again to  FIG. 1 , the cart  10  also has, in one embodiment, a liquid-absorbing surface  48  for the purpose of catching drips and leftover cleaning fluids is provided. The liquid-absorbing surface  48  is made from acrylics, bamboo, cellulose materials, cotton, high density polyethylene, low density polyethylene, polyester, polyolefins, polyurethanes, polyurethane-polyurea copolymers, rayons, superabsorbent polymers, wools, and blends of these materials. For example, the liquid-absorbing surface  48  can be a textile surface such as industrial felt, and may be placed proximate an exterior side of a glass balcony during the cleaning process. As a user cleans the glass, excess water and cleaning solution runoff is caught by the liquid-absorbing surface  48  and therefore prevented from reaching surfaces on the units that are below the glass being cleaned. 
     In one embodiment, extension arms  50  are configured to secure the liquid-absorbing surface  48 . In particular, each extension arm has an ascending portion  52  that attaches to an outrigger  38  and a descending portion  54  that attaches to the liquid-absorbing surface  48 . The extension arm  50  is configured in approximately an upsidedown “U” shape so that the arm  50  can extend up and over a glass balcony while the descending portion  54  projects downward so that the liquid-absorbing surface  48  is placed below or near the bottom region of glass balcony surface being cleaned, the liquid-absorbing surface  48  being supported between two extension arms  50 , and defining an outwardly projecting substantially horizontal surface. 
     In a related embodiment, the liquid-absorbing surface  48  is able to be mechanically raised and lowered about a balcony surface. The extension arms  50  ascending portions  52  are attached to extendable projections  56 . The extendable projections  56  raise the extensions arms  50  so that the extension arms  50  clear the top edge of a glass balcony top, and then lower the extension arms over the glass balcony top. The extendable projections  56  are, for example without limitation, linear actuators, screw-type jacks, and hydraulic rams. The raising and lowering of the extension arms  50  is controlled by the controls  22  of the control panel  20 . The controls  22  communicate with the extension arms  50  using connections  58  secured to the outriggers  38 . 
     The invention also contemplates a method of maintaining an exterior building surface.  FIG. 5  illustrates a person using the cart  10  as a secure point of tethering. The method includes positioning the cart  10  proximate and exterior surface in need of maintenance. In the illustration, the person is maintaining the structure by washing balcony glass. The cart  10  has a sufficient mass to act as a counterweight so that the person tethered to the cart  10  will be prevented from falling over the balcony. The outriggers  38  are unfolded to stabilize the cart. A line (L) is attached to a harness point  36  on the jib  28 , and the person in need of an anchor attaches the line (L) to himself. A liquid-absorbing surface  48  may optionally be deployed, as described herein. 
     Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.

Summary:
A portable folding support structure for safely tethering an individual comprises a portable cart sized to fit through a residential doorway, having wheels and a motor that actuates at least one of the wheels. A hand-operated throttle and steering device control the cart. The cart comprises an extendable anchoring plate to prevent rolling. A substantially horizontal jib with the cart comprises a harness point for receiving a safety cable to which an individual is attached to allow safe cleaning practices and to minimize fall risk. A foldable outrigger provides stability to the cart and an anchoring pad attaches to a distal region of the outrigger to promote stability. A textile liquid-absorbing surface is positionable about an outer surface of a glass balcony to inhibit cleaning liquids from spilling below the level of the liquid-absorbing surface.