Abstract:
A multiple task mobile working platform having a generally rectangular platform frame is provided. An adjustable scaffold leg member support allows for attachment of a variety of scaffolds of different dimensions. An angled tubular bracket allows for attachment of legs members in different positions to allow for maximum stability where there is sufficient space and for a more compact foot print when the working platform must be placed close to a building or object. Precise leveling of the working platform, removable safety side rails and an optional trailer are also disclosed.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates generally to the field of working platforms and scaffolds. More specifically it relates to a working platform which allows for the adjustable attachment of scaffolds and the adjustable attachment of various platform leg members.  
         [0003]     2. Description of the Prior Art  
         [0004]     Scaffolds are used for a variety of purposes in the building construction and maintenance trades, such as painting, plastering, electrical, masonry, carpentry, etc. Once erected, scaffolds are difficult to move throughout a jobsite without disassembly. U.S. Pat. No. 2,360,999 to Wyen, attempted to solve this problem by adding rollers on the bottom of the scaffolds. Although the scaffolds can be rolled from location to location within the jobsite, the ground on which the scaffolds are rolled has to be relatively flat for the scaffold to properly roll such as interiors of concrete warehouses, for example. When the device is used on uneven surfaces, such as rough excavated ground surfaces, it becomes difficult to maintain a safe foundation for use of the device. The Wyen devise also requires the scaffolds to be lifted off the rollers by using jack screws when a desired position was located.  
         [0005]     Another device, shown in U.S. Pat. No. 4,216,933 to Cramer, shows a similar scaffold platform, but it too has deficiencies in its leveling process. Its vertical leveling corner supports requires either a folk-lift, or similar piece of lifting machinery or actual man power to lift the platform to an elevation suited for use. The rigid vertical supports on this device have pre-drilled/pre-measured holes, where a pin is inserted for final adjustment. This requires the user to occasionally level the loose ground or use a leveling block under one or several of the corner supports. This arrangement could create a safety hazard to the overall stability of the unit if one or more of the leveling blocks would move or slide from under one of the vertical supports during usage.  
         [0006]     The most common solution for mobility is to provide for an easily disassembled scaffold. An example of such a device is shown in U.S. Pat. No. 650,900 to Knopfe. This device is made of simple and interchangeable parts adapted to be quickly assembled and disassembled for transportation and movement within a jobsite. This unit uses adjusting shoes attached to the lower base beams for leveling on uneven surfaces. U.S. Pat. No. 3,071,204 to Piltingsreed also has adjustable legs as well as a variable length. Other mobility solutions but limited, are shown in U.S. Pat. No. 3,480,110 to Coleman and U.S. Pat. No. 3,8850,264 to Salimas. In both designs, the devices provide for horizontal members extended from the main scaffolds on which a second platform is constructed. Instead of moving the scaffolds, they are extended instead. Both designs also have adjustable supporting legs and use a disassembly method for major mobility when in use.  
         [0007]     Many of the above mentioned designs have adjustable supporting legs and some have extended horizontal members. Some of these designs use a disassembly method of the scaffolds for mobility purposes. The present invention will allow its unit to be moved while scaffolds are erected, together with tools and material being stored on the working platform, along with the safety side rails installed. This will allow the user to not only move the scaffolds without disassembly but also transport the tools and material needed for the job at hand.  
         [0008]     While the prior art patents mentioned earlier offer some form of leveling support legs, the present invention utilizes screw type leveling jacks which allows exact leveling without the need for filler blocks which are required with the pre-drilled designs. Although several of the designs offer removable supporting legs, they are limited to only a few positions in which the supporting legs and supports can be positioned. This could cause difficult placement of the scaffold to a building or object when close confinement is inevitable. The present invention offers two positions for its screw jack bracket.  
         [0009]     None of the prior art patents teach or suggest a movable scaffold base member to allow an in/out and circular side by side movement in their scaffold bases. The prior art devices are limited and can only be used with certain scaffolds offered in today&#39;s market due to size and adjustment confinements in accepting the vertical scaffold legs. The present invention offers an adjustable scaffold base allowing the majority of all scaffold designs which are using a four vertical leg support design to be used.  
         [0010]     Without the supporting floor and safety rails, none of the previous mentioned patents can be used as an independent movable working platform, whereas this invention provides a safe and structurally secure working platform.  
       SUMMARY OF THE INVENTION  
       [0011]     The present invention provides a working platform (referred to as the main platform) which can be leveled at ground level by hand turning the screw jacks located at all four corners. The safety side rails will allow the unit to become a mobile working platform by using a forklift or a similar type of equipment. This invention will also allow the user to level the working platform on stable ground and erect multiple sections of scaffolds horizontally which can be then moved in a fully assembled form to various locations on a jobsite. If the invention is being used on a hard and level surface such as concrete, optional rollers can be attached to the unit in place of the hand screw jacks. This will enable the unit to be “rolled” freely on top of the hard, level surface. The provision of a licensed trailer specially designed to secure a working platform permits the user to transport the unit to and from a jobsite. The working platform also provides additional space to haul tools and materials to a job site.  
         [0012]     The present invention provides adjustable attaching means located near each of said four corners which in one embodiment of the invention comprises an adjustable scaffold leg member support which includes adjustable base plates to secure multiple level scaffolds.  
         [0013]     A main platform is preferably provided with safety side rails which permit the invention to be used for a variety of tasks. Although many of the prior art devices are based on a mobile scaffold base design, the present invention can be used to establish a safe and secure mobile working platform which can be elevated to required heights to complete the job at hand by the use of a forklift or the like.  
         [0014]     Depending on the actual job being completed, many manufactures require different distances between the bottom supports of their scaffold. The present invention offers adjustable base plates which allow the present invention to be used with a majority of the scaffolds offered in today&#39;s market.  
         [0015]     The present invention provides novel adjustable screw leveling corners jacks which enable the user of said invention to level the main platform on uneven surfaces at any elevation. Such a design is a great improvement over the prior art which offers pre-drilled/pre-determined adjustable heights in their supporting vertical supports often requiring shims or blocks for leveling.  
         [0016]     The present invention provides adjustable attaching means located near each of said four corners which in another preferred embodiment of the invention comprises angled tubular brackets which support the corner screw jacks. The angled tubular brackets are reversible and can be positioned in an outward or in an inward position. The inward position allows the working platform to be placed directly against a wall or work area assuring a safe environment since there will be little or no distance between the platform and object being worked on. When the invention is not attached to a forklift or the like, the unit can become its own working platform on level or uneven terrain.  
         [0017]     With the main platform secured to a licensed trailer, the unit can be towed to and from a jobsite utilizing existing highway systems. The trailer also provides a means for the user to transport the tools and material to said job while the main platform is secured to the trailer.  
         [0018]     In its simplest form, the present invention provides a multiple task mobile working platform comprising: a generally rectangular platform frame having four corners, a pair of spaced apart tubular end members, a pair of spaced apart tubular side members and plural spaced apart cross bar members extending between said side members, said frame adapted for use in a generally horizontal orientation; and adjustable attaching means provided near each of said four corners of said frame, each attaching means adapted to removably secure a functional vertical member to said frame in a selected one of a plurality of locations.  
         [0019]     Preferably, said frame member and said crossbar members are formed from thick steel box tubing and are welded together and a floor member is provided to cover an upper side of said frame. Preferably, the floor member is formed from a thick steel mesh.  
         [0020]     In one embodiment, said adjustable attaching means comprises an adjustable scaffold leg member support, said scaffold leg member support member being movable and adjustable to permit a user to selectively install any one of a variety of commercially available scaffolds onto the working platform. Preferably, said adjustable scaffold leg member support is bolted onto said frame and includes a base plate having an elongated opening therein and a vertically extending tubular post member adapted to receive and support a leg of a scaffold. Preferably, a screw member is threaded into said tubular post member whereby turning said screw member tightens a leg of a scaffold firmly into said tubular post member and further secures a scaffold on said frame.  
         [0021]     In another embodiment, said adjustable attaching means comprises an angled tubular bracket which is removably inserted and attached to said frame. The angled tubular bracket has an insertion end and an extension end, said extension end extending from said insertion end at an angle of between 100° and 170°. Preferably, said angle is approximately 135°. Said angled tubular bracket is reversible and extends outwardly away from a longitudinal centerline of said frame when inserted in a first position and extends inwardly towards a longitudinal centerline of said frame when inserted in a second upside down position. Preferably, said angled tubular bracket further comprises a frame leg support bracket mounted for rotational movement on said extension end. Preferably, said frame leg support bracket is attached to a frame leg in the form of an adjustable screw leveling corner jack which permits the working platform to be leveling on uneven surfaces. Alternatively, said frame leg support bracket may be attached to a frame leg having a wheel on a lower end thereof. Preferably, said frame leg support bracket selectively secures a frame leg to the frame in vertical position for use on the ground and in a horizontal position for storage or use above the ground.  
         [0022]     Preferably, the present invention utilizes adjustable attaching means which comprises both an adjustable scaffold leg member support and which further comprises an angled tubular bracket. Such an arrangement provides an enormous amount of flexibility in the use of the working platform.  
         [0023]     Preferably, said frame further comprises a pair horizontal fork tubes mounted below the frame, said fork tubes sized and spaced to receive fork tines of a fork lift whereby the platform may be lifted above the ground by a fork lift. Preferably said frame further comprises plural safety rail brackets and said platform further comprises removable safety rails which surround an individual while using the working platform.  
         [0024]     Finally, the present invention also preferably further comprising a trailer to which the working platform can be secured for the purpose of transporting the working platform and any scaffolds or equipment secured to or positioned on the working platform.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]      FIG. 1  is a perspective view of the main platform frame of the present invention having horizontally and vertically adjustable support legs with adjustable base plates for the erection of scaffolds.  
         [0026]      FIG. 2  is a perspective view of an embodiment of a safety side rail design to be installed on  FIG. 1  when the main platform frame is being used as a working platform.  
         [0027]      FIG. 3  is a perspective view of a licensed trailer used to transport the main platform frame of  FIG. 1  and side rails of  FIG. 2 .  
         [0028]      FIG. 4  is a perspective view of an angled bracket in an “out” position and a screw jack leg in a vertical position.  
         [0029]      FIG. 5  is a perspective view of an angled bracket in an “out” position and a screw jack leg in a horizontal position.  
         [0030]      FIG. 6  is a perspective view of an angled bracket in an “in” position and a screw jack leg in a horizontal position.  
         [0031]      FIG. 7  is a perspective view of the main platform frame, safety rails and trailer of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]     Referring to  FIGS. 1-7  the presently preferred embodiments of the present invention are depicted. In  FIG. 1 , a standard sized 5′-6″×8′ portable working platform and scaffold support base referred to as the main platform is shown. The main platform comprises of a rectangular frame  100  formed by 3″×4″×⅜″ thick box steel tubing members  1 ,  2 ,  3  and  4  which are welded together at each of their ends. Reinforcing the rectangular working platform are seven cross bars  5 , which are made up of rectangular 2″×4″×⅜″ thick steel box tubing. All seven cross bars  5  are equally spaced and in a parallel spacing between the outside frame end tubes  2  and  4 . Each of the seven cross bars  5  are welded on each of their ends to the outside side frame tubes  1  and  3 . The main platform frame has a longitudinal center line  101 .  
         [0033]     Eight sleeves  6  are fabricated from ⅜″ flat steel and are sized to receive the bottom of vertical posts  29  of safety rails  200  ( FIG. 2 ). Once the eight sleeves  6  are bent to shape they are drilled with a 9/16″ drill creating holes  7  which will accept the securing “T” handled pins  37 . Once the holes  7  are drilled, then all eight sleeves  6  are spaced, with two sleeves  6  per outside frame tubes  1 ,  2 ,  3 , and  4  to assure proper spacing to accept the insertion of the vertical support posts  29  of the safety side rails  200  shown on  FIG. 2 . Once properly spaced, the eight sleeves  6  are welded on the outside frame tubes  1 ,  2 ,  3 , and  4 .  
         [0034]     Two rectangular 3″×5″×½″ thick horizontal fork tubes  8  are cut to a 5′-6″ length for the purpose to receive the insertion of forks of a fork lift or like and. Once the fork tubes  8  are cut to length, they are spaced at 3′-6″ apart in a parallel position centered from outside frame tubes  2  and  4 . Once the fork tubes  8  are positioned, they are welded on both ends to the bottom side frame tubes  1  and  3  and any adjoining cross bars  5 .  
         [0035]     Four ⅜″ thick steel angled corner braces  9  are fabricated and drilled to accommodate a ½″ course thread bolt  14 , ½″ flat washers  13  and a ½″ course thread nut  12 . The four angled corner braces  9  are then welded to each of the outside frame tubes  1 ,  2 ,  3 , and  4  (as shown on  FIG. 1 ).  
         [0036]     A ¼″ thick steel meshed floor  20  is sized to the perimeter of the outside frame tubes  1 ,  2 ,  3 , and  4 . Once cut to size, the floor  20  is placed on the top side of the outside frame tubes  1 ,  2 ,  3 , and  4  and seven cross bars  5  and welded with a minimum of six inch spacing at all intersecting points to said frame tubes  1 ,  2 ,  3  and  4  and cross bars  5 .  
         [0037]     An adjustable attaching means in the form of adjustable scaffold leg member support includes a scaffold base plate  10  is fabricated starting with a 90 degree ½″ thick piece of steel, with two of the sides of said plate to be a minimum length of 12″. The third side of the scaffold base plate  10  is cut on a slow outside radius. The scaffold base plate  10  is sized and notched with an elongated opening  11  to accommodate the diameter of the bolt  14 , creating a in/out and circular side by side adjustable motion at the corner of said scaffold base plate  10 . Following the cutting of the scaffold base plate  10 , a 2″ outside diameter, ⅜″ thick steel pipe  23  is cut to an 8″ length. Once the steel pipe  23  is cut, a hole is drilled and threaded to accommodate a ½″ course thread bolt  22  used to secure the bottom portion of a scaffold vertical leg. The steel pipe  23  is centered between the end of the opening  11  and the edge of the radius of the scaffold base plate  10  and welded in a perpendicular position on the scaffold base plate  10 . Finally, the four assembled scaffold leg member support base plates  10  are mounted at each corner of the main platform  100  and attached to said platform through the four ⅜″ thick steel angled corner braces  9  previously welded by asserting the bolt  14 , washers  13  and nut  12 .  
         [0038]     An adjustable attaching means in the form of four angled tubular brackets  15 , which are the supports for attaching the adjustable screw leveling corners jacks  24  or, alternatively, the 360 degree rotating rollers  24 A, are fabricated. Each angled tubular bracket  15  has an insertion end which is designed to slide into each corners of the working platform, at the ends of the box steel tubes  1  and  3 . The angled tubular brackets  15  are secured into a locking position with a ½″ “T” handled pin  16  which is inserted into a 9/16″ diameter drilled holes found on each corner of the main platform  100 , through a pre-drilled hole found on the angled tubular brackets  15 . To fabricate angled brackets  25 , you begin with a tubular piece of steel sized to slide into each end of the tubes  1  and  3 . Said steel is then cut in half on one end at a 22½degree angle with a straight cut on the other end, whereas the other piece is cut on both ends at 22½degree angles. Once cut, the 22½degree angled cut ends of the angled tubular brackets  15  are welded together creating a 45 degree welded angle. On the straight cut insertion end of the bracket  15 , a 9/16″ hole is drilled to match the 9/16″ pre-drilled holes on both ends of tubes  1  and  3 . This allows the ½″ diameter “T” handled pin  16  mentioned earlier to be inserted to secure the bracket  15 . On the other extension end of the bracket  15 , a 2″ long, 1¼″ diameter, ¼″ thick pipe  18  is welded on the bracket  15 . A 9/16″ hole  119  is drilled and matched into said pipe  18  to allow the adjustable screw leveling corners jacks  24  to be secured with a ½″ “T” handled pin  19  when inserted. The insertion end and extension end of bracket  15  are joined at a 135° angle.  
         [0039]     Two safety chains  21  used to secure the main platform to the forklift or the like are fabricated. First, two ⅜″ thick link chains  21  are cut to a 2′ length each. Then one ⅜″ thick snap ring is placed on one end of each 2′ safety chain  21 . Once the snap rings are installed, the other end of each safety chain  21  is welded three inches towards the center of rail  3  from the inside of each forklift rectangular tube  8 .  
         [0040]     The safety side rails  200  of  FIG. 2 , which are optionally attached to the main platform  FIG. 1  by sliding the vertical side posts  29  into the two sleeves  6  found on each side tube  1 ,  2 ,  3 , and  4 , are fabricated from 2″×3″×⅜″ thick box steel. First the top rails  25 ,  26 ,  27  and  28  are cut to a length to assure a proper measurement in order to fit outside the main platform. Then the ends of rails  25  and  27  are notched and a flange  34  is bent in a 90 degree downward angle. The notched flange  34  allows both ends of the  25  and  27  rails to fit over rails  26  and  28  and be secured with a ½″ “T” handled pin inserted in a pre-drilled 9/16″ hole drilled through the flange  34  and the ends of rails  26  and  28 . Once the four top rails  25 ,  26 ,  27  and  28  are completed, eight vertical posts  29  are fabricated from 2″×3″×⅜″ thick box steel at a 43″ length each. Then two vertical posts  29 , spaced to slide into the sleeves  6  are welded per each top rail  25 ,  26 ,  27  and  28 . Once the vertical posts  29  are welded to the top rails, a 9/16″ hole is measured and drilled at the bottom of each post  29  to assure an exact alignment allowing a ½″ “T” handled pin to be placed through the said 9/16″ hole and the hole  7  previously drilled in the sleeves  6 . Once the 9/16″ holes are drilled on the bottom section of each vertical post  29 , then the bottom rails  30 ,  31 ,  32  and  33  are fabricated by following the same procedure used when the top rails  25 ,  26 ,  27  and  28  were made, but one exception in design of the bottom rails  30 ,  31 ,  32  and  33  from the top rails  25 ,  26 ,  27  and  28  is apparent. Each vertical post  29  runs continuous through the bottom rails  30 ,  31 ,  32  and  34 . This requires the bottom rails  30 ,  31 ,  32  and  34  to be cut into three spaced sections to complete the full length measurement required. Also rails  30  and  32  require the same flange and 9/16″ hole  34  design found on rails  25  and  27 . Once the bottom rails  30 ,  31 ,  32  and  33  are cut to size and flanges  34  are drilled, each appropriate section of the bottom rails  30 ,  31 ,  32  and  34  are welded to the vertical posts  29  at a six inch distance from the bottom of each vertical post  29 .  
         [0041]     The next item to be fabricated is the trailer which is shown in  FIG. 3  in which the main platform  FIG. 1  and safety side rails  FIG. 2  can be transported to and from jobsites along with the ability to transport the unit within a job location. Starting with the center beam  38 , fabricated from a 3″×4″×⅜″ thick piece of tubular steel and cut at an overall length of 96″. A rear cross member  41 , also a 3″×4″×⅜″ thick piece of tubular box steel, is cut at a 72″ length. The center beam  38  is placed in the center of the rear cross member  41  in a perpendicular angle and welded to the rear cross member  41 . Once the center beam  38  and rear cross member  41  are welded, two angle braces  39  and  40 , also 3″×4″×⅜″ pieces of tubular box steel, are cut with the appropriate angle shown on  FIG. 3 . Immediately after the angle braces  39  and  40  are completed, they are positioned as shown on  FIG. 3  and welded to the center beam  38  and the rear cross member  41 . The axle assembly, made up of a 7,000 pound capacity axle  42  equipped with a rubber suspension including two 7″ wide×15″ diameter wheels  44  covered with a 200/75R15 tires  43  which are secured to the axle  42  by five lugs  45  per wheel, are all installed to the base of the rear cross member  41  with supporting brackets. Following the axle assembly installation, the front screw jack  51  is installed 14″ back from the end of the center beam  38  by inserting over a receiving collar resembling the 2″ long, 1¼″ diameter, ¼″ thick pipe  18  welded on bracket  15  shown on  FIG. 1 . Screw jack  51  is then secured on the center beam  38  with a “T” handle pin  52  when placed over the receiving collar  18 . Two fenders  46  are installed on the rear cross member  41 . To the rear of each fender  46 , tail lights  57 , required for licensing the trailer are installed. The required wiring from the rear tail lights  57  is then attached under each fender  46  and pulled through the center of each appropriate angle brace  39  and  40  and continued through the center beam  38  to the front of the trailer, with a 20″ piece of wire harness extending past the end of the trailer. On the end of the extended wire harness, an electrical male 12 volt trailer plug  55  is connected.  
         [0042]     A 2″ trailer ball receiver  56  is then attached on the front of the center beam  38  by drilling two 9/16″ holes through the receiver  56  and center beam  38 . Once drilled, two ½″ course threaded bolts are inserted all the way through the receiver  56  and center beam  38 . Two ½″ flat washers are placed on the bolts, with two ½″ Nylock, course thread nuts tightened on said bolts. Following the attachment of the receiver  56 , two-⅜″ thick links, 24″ in length safety chains  53  are bolted with ⅜″ nuts and bolts to the front and bottom of the center beam  38 . Attached on each end of the safety chains  53  is a snap ring which is used to attach said trailer to the towing vehicle. Finally, 3″×3″×½″ thick steel angle securing plates  47  and  49  are cut and then placed as shown on  FIG. 3  to accept the main platform  FIG. 1 . Once the securing plates  47  and  49  are in position, they are then welded into position (the angle securing plates  47  onto the fenders  46  and the angle securing plates  49  onto the center beam  38 ).  
         [0043]     When the user plans to transport the main platform  FIG. 1 , said main platform is placed on the trailer  FIG. 3  and secured with two “T” handled pins  48  in the rear through the securing plates  47  and one “T” handled pin  50  through the securing plates  49 .  
         [0044]     Referring to  FIG. 4 , the adjustable attaching means is in the form of an angled tubular bracket  15  which is removably inserted and attached to said frame. The angled tubular bracket has an insertion end and an extension end attached at an angle relative to said insertion end of between 100° and 170° preferably approximately 135°. In  FIG. 4  the angled tubular bracket  15  extends outwardly away from a longitudinal centerline  101  of said frame  100 . The screw jack  24  is held by the frame leg support bracket  125  in a vertical position by placing T-handed pin in hole  18 A of collar  18 . Collar  18  connects the frame leg support bracket  125  for rotational movement on the extension end of bracket  15 . In  FIG. 5 , the screw jack  24  is held by the frame leg support bracket  125  in a horizontal position by placing T-handed pin in hole  18 B of collar  18 . In  FIG. 6 , the angled tubular bracket  15  extends inwardly towards a longitudinal centerline  101  of said frame  100 .  
         [0045]      FIG. 7  shows the relative general location and orientation of the main platform frame  100 , safety side rails  200  and trailer  300  prior to connection and assembly thereof.  
         [0046]     While I have shown and described the presently preferred embodiments of my invention, the invention is not limited thereto and may be otherwise variously practiced within the scope of the following claims: