Patent Publication Number: US-8985275-B2

Title: Lift safety system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     I hereby claim benefit under Title 35, United States Code, Section 120 of U.S. patent application Ser. No. 13/536,140 filed Jun. 28, 2012. This application is a continuation of the Ser. No. 13/536,140 application. The Ser. No. 13/536,140 application is currently pending and is scheduled to be granted on Oct. 21, 2014 with a patent number of U.S. Pat. No. 8,863,899. The Ser. No. 13/536,140 application is hereby incorporated by reference into this application. The Ser. No. 13/536,140 application claims priority to U.S. Provisional Application No. 61/502,421. 
     I hereby claim benefit under Title 35, United States Code, Section 119(e) of U.S. provisional patent application Ser. No. 61/502,421 filed Jun. 29, 2011. The 61/502,421 application is now abandoned. The 61/502,421 application is hereby incorporated by reference into this application. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable to this application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a portable lift and more specifically it relates to a portable modular lift system that may be easily transported to a lifting location and compactly stored when not in use. 
     2. Description of the Related Art 
     Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field. 
     Conventional lift systems have been in use for years for elevating workers, materials and the like to elevated locations. Lift systems are utilized by maintenance workers, sound and light professionals, home owners, warehouse owners and the like to reach elevated locations. Conventional lift systems utilize one or more vertically orientated masts. The masts are typically attached to the side or wall of the structure to be worked upon with bracing. The masts may be comprised of a unitary structure or a modular structure. The modular masts are comprised of mast sections that are secured together in a vertical manner with conventional fasteners to form an elongated mast structure. A support platform is movably positioned upon the masts and may be elevated/lowered utilizing an electric motor or other power source. An example of a unitary mast configuration utilized for elevating workers and materials is U.S. Pat. No. 6,981,573 to Nickel and owned by Reechcraft, Inc. The Reechcraft patent discloses a pair of vertical posts that support a movable platform between thereof and that utilizes braces attached between the posts and the wall structure. 
     One problem with conventional lift systems is that they are relatively heavy making them difficult to transport to a work area. Another problem with conventional lift systems is that they are time consuming to assemble because they require tools and manual assembly with fasteners to attach the modular masts together. 
     A further problem with conventional lift systems is that they are difficult to transport and are not designed to be easily utilized in smaller sized locations like the interiors of buildings. Another problem with conventional lift systems is that they typically require more than one worker to assemble, utilize and disassemble. A further problem with conventional lift systems is that they require attachment of the masts to the side of a building structure being worked upon. Another problem with conventional lift systems is that they are expensive and complex making them difficult to utilize on smaller projects. 
     Because of the inherent problems with the related art, there is a need for a new and improved portable modular lift system that may be easily transported to a lifting location and compactly stored when not in use. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention generally relates to a portable lift which includes a support base having a plurality of base wheels, a plurality of mast sections connectable to one another to form a vertical mast, a support platform movably positioned upon the vertical mast, and a drive unit connected to the support platform to elevate and lower the support platform upon the mast sections. The mast sections include a plurality of receiver apertures within a first end and a plurality of locking pins extending from a second end that are catchably received within the corresponding receiver apertures. 
     There has thus been outlined, rather broadly, some of the features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and that will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is an upper perspective view of the present invention in a compact storage position. 
         FIG. 2  is an upper perspective view of the present invention being assembled. 
         FIG. 3  is an upper perspective view of the present invention fully assembled. 
         FIG. 4   a  is a magnified upper perspective view illustrating two mast sections being initially positioned together in an unlocked state with the securing lever in the released position and with the locking lever in the locked state to prevent movement of the securing levers. 
         FIG. 4   b  is a magnified upper perspective view illustrating the two mast sections with the locking lever moved to a release state to allow for movement of the securing levers. 
         FIG. 4   c  is a magnified upper perspective view illustrating the securing lever positioned in the locked position to lock the locking pins within the receiver apertures by the locking shaft. 
         FIG. 4   d  is a magnified upper perspective view illustrating the securing lever positioned in the locked position and the locking lever in the locked state to prevent movement of the securing levers. 
         FIG. 5   a  is a side cutaway view of a first mast section positioned above a second mast section prior to connection thereof 
         FIG. 5   b  is a side cutaway view of the first mast section connected to the second mast section with the locking shaft rotated to lock the locking pins. 
         FIG. 6   a  is a bottom end view of a mast section showing the locking lever in the locked state to prevent movement of the securing levers. 
         FIG. 6   b  is a bottom end view of a mast section showing the locking lever in the release state to prevent movement of the securing levers. 
         FIG. 7   a  is a side cutaway view showing the securing levers in the released position extending outwardly thereby preventing passage of the guide wheels upwardly onto the next mast section. 
         FIG. 7   b  is a side cutaway view showing the securing levers in the released position extending outwardly with the guide wheels engaging the extended securing levers thereby preventing passage of the guide wheels upwardly onto the next mast section. 
         FIG. 7   c  is a side cutaway view showing the securing levers in the locked position thereby allowing passage of the guide wheels upwardly onto the next mast section. 
         FIG. 8   a  is a side view of an upper mast section positioned above a lower mast section with a sequencing pin extending from the lower end in a first position of the upper mast section and aligned with a sequencing aperture extending within the upper end of the lower mast section in a first position corresponding to the sequencing pin. 
         FIG. 8   b  is a side view of an upper mast section positioned above a lower mast section with a sequencing pin extending from the lower end in a second position of the upper mast section and aligned with a sequencing aperture extending within the upper end of the lower mast section in a second position corresponding to the sequencing pin. 
         FIG. 8   c  is a side view of an upper mast section positioned above a lower mast section with a sequencing pin extending from the lower end in a third position of the upper mast section and aligned with a sequencing aperture extending within the upper end of the lower mast section in a third position corresponding to the sequencing pin. 
         FIG. 8   d  is a side view of an upper mast section positioned above a lower mast section with a sequencing pin extending from the lower end in a fourth position of the upper mast section and aligned with a sequencing aperture extending within the upper end of the lower mast section in a fourth position corresponding to the sequencing pin. 
         FIG. 9   a  is a top end view of a mast section illustrating the sequencing aperture. 
         FIG. 9   b  is a bottom end view of the mast section illustrating the sequencing pin. 
         FIG. 10  is an upper perspective view of the outer leg removed from the inner leg. 
         FIG. 11  is an upper perspective view of the support platform elevated above the support base. 
         FIG. 12  is an upper perspective cutaway view of the inner leg and outer leg. 
         FIG. 13   a  is a side cutaway view of the outer leg with no weight supported by the corresponding adjustment member. 
         FIG. 13   b  is a side cutaway view of the outer leg with weight supported by the corresponding adjustment member thereby releasing the locking detent and the corresponding finger member. 
         FIG. 13   c  is a side cutaway view of the outer leg with weight supported by the corresponding adjustment member and with the corresponding finger member removed from the corresponding guide member. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A. Overview. 
     Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views,  FIGS. 1 through 13   c  illustrate a portable modular lift system  10 , which comprises a support base  20  having a plurality of base wheels  28 , a plurality of mast sections  30  connectable to one another to form a vertical mast, a support platform  50  movably positioned upon the vertical mast, and a drive unit  60  connected to the support platform  50  to elevate and lower the support platform  50  upon the mast sections  30 . The mast sections  30  include a plurality of receiver apertures  32  within a first end  31  and a plurality of locking pins  38  extending from a second end  37  that are catchably received within the corresponding receiver apertures  32 . 
     B. Support Base. 
       FIGS. 1 and 2  best illustrate the support base  20  which is utilize to provide support and stability to the present invention when in use. The support base  20  is comprised of a portable structure that is preferably lightweight which allows for easy transportation by a single individual. The support base  20  may be comprised of various types of materials such as but not limited to aluminum, steel and the like. 
     The support base  20  includes a plurality of legs that extend outwardly along a horizontal plane. The legs may extend outwardly in various patterns such as but not limited to an X-shaped pattern. There are preferably at least two front set of legs and two rear set of legs as illustrated in  FIGS. 2 and 3  of the drawings. The legs may be comprised of a stationary leg structure, pivoting leg structure, telescoping leg structure or a removable leg structure. It is preferable that the legs have a compact state for storage and transportation as shown in  FIG. 1  of the drawings, and an extended state for providing stability during use of the present invention as shown in  FIGS. 2 and 3  of the drawings. 
       FIGS. 1 through 3  illustrate a removable leg structure wherein the legs are comprised of a plurality of inner legs  22  and a plurality of corresponding outer legs  24  that are received within the interior of the inner legs  22 . The outer legs  24  are removed when the present invention is in the compact state and stored within the storage receivers  29  attached to the support base  20  as illustrated in  FIG. 1  of the drawings. The storage receivers  29  are comprised of vertically orientated tubular receivers that receive an inner end of the outer legs  24  for storage as shown in  FIG. 1 . 
     The support base  20  preferably has a width of 30 inches or less when the plurality of legs are in the compact state to allow for passage through doorways and other narrow areas. The support base  20  preferably has a width of 53 inches or more when the plurality of legs are in the extended state to provide stability to the present invention when in use. 
     The support base  20  preferably includes a plurality of wheels to assist in the transportation of the present invention from one location to another. As illustrated in  FIGS. 1 and 2  of the drawings, the plurality of wheels preferably include of a pair of base wheels  28  attached to a rear portion of the support base  20  that provide for transportation between various locations and upon various types of terrain (e.g. stairs, grass). as illustrated in  FIGS. 1 and 2  of the drawings. A handle  18  having a U-shaped structure with opposing upper wheels  19  is preferably attached to the base mast as shown in  FIG. 1  to provide additional support for the present invention when loading horizontally on to a flat surface such as a vehicle (e.g. pickup, truck). 
     The plurality of wheels further preferably includes a plurality of caster wheels  21  that allow for horizontal movement of the present invention upon a flat surface. The base wheels  28  are larger than the caster wheels  21  to provide for increased mobility over uneven terrain. The base wheels  28  may be constructed of a non-pneumatic tire structure (e.g. flat free tire) or a pneumatic tire structure. The base wheels  28  are preferably sufficient in size to allow for transport of the present invention up and down stairs. The bottom ends of the base wheels  28  are preferably higher than the lower end of the caster wheels  21  so that only the caster wheels  21  are supporting the present invention when in a substantially horizontal state and only the base wheels  28  support the present invention when inclined rearwardly. The caster wheels  21  are connected to the distal portions of the inner legs  22  to provide for maximum stability during movement when in the compact storage position as illustrated in  FIG. 1  of the drawings. 
     The outer legs  24  each include an adjustment member  26  as illustrated in  FIGS. 2 ,  3 ,  10  and  11  of the drawings. Each adjustment member  26  is preferably comprised of a threaded shaft that includes a coupler at the upper end thereof for allowing a wrench or drill to connect to for rotation thereof. Each adjustment member  26  includes a pad  27  at the lower end thereof that engages a ground surface supporting the present invention. The pad  27  is preferably comprised of a broad structure to prevent damage to the surface and to provide increased stability. 
     The outer legs  24  are secured within the inner legs  22  by a detent structure or fastener. Each of the inner legs  22  include a guide member  70  having an upper tapered opening that receives a corresponding finger member  55  extending downwardly from the support platform  50 . The finger members  55  are preferably attached to a pair of extended members  56  that extend from the support platform  50  as illustrated in  FIG. 11  of the drawings. The finger members  55  extend downwardly and are aligned with the openings within the guide members  70  so when the support platform  50  is fully lowered, the finger members  55  are positioned within the guide members  70  and when the support platform  50  is elevated slightly the finger members  55  are outside of the guide members  70 . 
     Each inner leg  22  includes a lower biased unit  72  that is positioned within a lower interior portion of the inner leg  22  below each of the guide members  70  to allow for selective engagement of the upper end of the lower biased unit  72  with the lower end of the finger members  55 . A flanged end member  74  extends horizontally from the lower biased unit  72  and extends through a slot  25  within a partition member  23  within the outer leg  24 . 
     Each outer leg  24  preferably includes an upper bushing  80  and a lower bushing  82  as illustrated in  FIG. 12  of the drawings. The upper bushing  80  and the lower bushing  82  each preferably have an interior flange that is larger than the aperture within the outer leg  24  positioned within. A first engaging member  84  is threadably attached to each adjustment member  26  between the upper bushing  80  and the lower bushing  82 . The first engaging member  84  has a width that is slightly less than the interior width of the outer leg  24  thereby preventing rotation of the first engaging member  84  when the adjustment member  26  is rotated. The first engaging member  84  has a tapered end that selectively engages a corresponding tapered end of a second engaging member  86  as shown in  FIG. 12 . The second engaging member  86  is positioned upon an alignment pin  87  and is biased towards the first engaging member  84  with a biasing device (e.g. spring). An elongated shaft  88  is attached to the second engaging member  86  and passes through an aperture within the partition member  23  and selectively engages a locking detent  57  within the corresponding finger member  55  as shown in  FIGS. 12 through 13   c  of the drawings. 
     When the pad  27  is not bearing any weight, the first engaging member  86  is adjacent to and touching the lower bushing  82  as illustrated in  FIG. 13   a . When the pad  27  engages the ground surface and is bearing weight, the first engaging member  84  is elevated within the outer leg  24  to engage the upper bushing  80  and also engaging the second engaging member  86  as illustrated in  FIGS. 13   b  and  13   c  of the drawings. 
     C. Vertical Mast. 
     It is preferable to have a single vertical mast constructed from the plurality of interconnected mast sections  30  as illustrated in  FIGS. 2 and 3  of the drawings. However, more than one vertical mast may be constructed utilizing the present invention in situations that require more than one vertical mast to increased strength and stability. The vertical mast includes a track  33  extending up the length of the vertical mast that the drive unit  60  engages (e.g. with a sprocket or gear) to elevate and lower the support platform  50  with respect to the vertical mast. The vertical mast further includes a pair of opposing side channels  34  that receive the guide wheels  54  of the support platform  50 . 
     The vertical mast extends upwardly from the support base  20  as illustrated in  FIGS. 2 and 3  of the drawings. The vertical mast is comprised of a plurality of mast sections  30  removably connected to one another to form the vertical mast that extends upwardly from the support base  20 . The vertical mast may be constructed of various numbers of mast sections  30  (e.g. 2, 3, 4, 5, etc.) and each of the mast sections  30  may be comprised of the same or different lengths (e.g. 2 feet, 4 feet, 6 feet). 
     While not required, it is preferable to have a base mast that is permanently or semi-permanently attached to the support base  20  as illustrated in  FIG. 1  of the drawings. The permanent attachment of the base mast increases stability and provides a partial assembly of the present invention. The base mast may also have the same length or be longer than the other mast sections  30 . The upper end of the base mast includes a coupler that is capable of receiving the next mast section  30  similar to the ends of the mast sections  30  as discussed further herein. Alternatively, one of the plurality of mast sections  30  may be removably attached to the support base  20  instead of having a base mast. 
     The plurality of mast sections  30  each have a first end  31  and a second end  37 . The first end  31  may be comprised of the upper end or the lower end of the respective mast section  30 . The second end  37  of the respective mast section  30  is opposite of the first end  31  and may be comprised of the upper end or the lower end of the respective mast section  30 . The first end  31  and the second end  37  of the mast sections  30  are preferably parallel with respect to one another. 
     The first end  31  of each mast section  30  includes a first coupler and the second end  37  of each mast section  30  includes a second coupler. The first coupler is removably connectable to the second coupler to removably connect the plurality of mast sections  30  in a vertical and aligned manner. The first coupler and the second coupler allow for secure and relatively non-moving attachment of the mast sections  30  with respect to one another. 
     As shown in  FIGS. 8   a  through  8   d  of the drawings, a sequencing aperture  16  is preferably positioned within the first end  31  of the mast section  30  that corresponds to a sequencing pin  14  extending from a second end  37  of a mast section  30  designed to be positioned above the initial mast section  30 . To ensure that the proper combination of mast sections  30  are assembled in the proper order, alignment and to limit the height of the assembled vertical mast (i.e. with the track  33  aligned for each of the mast sections  30  the sequencing aperture  16  could be positioned within the opposite side of the track  33 ), the sequencing aperture  16  for each of the mast sections  30  is different and the sequencing pin  14  for each of the mast sections  30  is different.  FIGS. 8   a  through  8   d  illustrate utilizing a steadily moving set of sequencing apertures  16  and sequencing pins  14 . The upper most mast section  30  would not have a sequencing pin  14  or sequencing aperture  16  at the upper end thereof. The upper most mast section  30  preferably does not have any sequencing aperture  16  or receiver apertures  32 . 
     Each of the plurality of mast sections  30  preferably has a rectangular cross section (e.g. square shaped) and are comprised of extruded aluminum to provide for a cost-effective, lightweight structure capable of supporting the support platform  50  along with cargo. It can be appreciated that the mast sections  30  may be comprised of various other cross sections (e.g. circular, hexagonal, triangular, etc.) The first end  31  and the second end  37  of each of the mast sections  30  is preferably flat and transverse with respect to the longitudinal axis of the respective mast sections  30  to maximize the physical contact between the first end  31  of a first mast section  30  and a second end  37  of an adjacent mast section  30 . Each of the mast sections  30  includes a track  33  on one side thereof that the drive unit  60  engages. The track  33  for each of the mast sections  30  is aligned when assembled into the vertical mast. Each of the mast sections  30  also includes the opposing pair of side channels  34 . The side channels  34  for each of the mast sections  30  are aligned when assembled into the vertical mast thereby creating a single elongated pair of side channels  34  within the vertical mast allowing free passage of the guide wheels  54 . 
     The first coupler and the second coupler are each preferably comprised of a plurality of receiver apertures  32  or a plurality of locking pins  38  that are received within the receiver apertures  32 . If the first coupler is comprised of the receiver apertures  32  then the second coupler is comprised of the locking pins  38  to allow for interconnection of two or more mast sections  30 . The first coupler is aligned with the second coupler for each of the mast sections  30  to allow for interconnection of each of the mast sections  30 . 
       FIGS. 8   a  through  8   d  illustrate the receiver apertures  32  within the first end  31  (the first end  31  is shown as the upper end in the figures whereas the first end  31  could be the lower end alternatively). The receiver apertures  32  are formed to have an upper tapered portion to help guide the locking pins  38  into the receiver apertures  32  with the middle to lower portions of the receiver apertures  32  formed to snugly receive the locking pins  38  with limited movement to ensure a stable vertical mast when constructed. The plurality of receiver apertures  32  are preferably comprised of four corner receiver apertures  32  positioned adjacent to each corner of the first end  31  of the mast section  30  as illustrated in  FIG. 9   a  of the drawings. 
     The plurality of receiver apertures  32  removably receive the plurality of locking pins  38  in a catchable manner. The locking pins  38  have a length sufficient to ensure secure reception within the receiver apertures  32  (e.g. at least one inch). The locking pins  38  are also preferably comprised of four corner locking pins  38  positioned adjacent to each corner of the second end  37  of the mast section  30  The plurality of locking pins  38  each include a locking channel  39  that extends through a side portion of the locking pins  38  transverse with respect to the longitudinal axis of the locking pins  38 . The locking channel  39  allows the locking shaft  44  to pass through and selectively prevent the locking pins  38  from exiting the receiver apertures  32 . The plurality of locking pins  38  extend parallel with respect to a longitudinal axis of the plurality of mast sections  30 . 
     One or more locking shafts  44  are rotatably positioned within each of the plurality of mast sections  30  and partially extend into at least two of the plurality of receiver apertures  32  to selectively engage the locking pins  38 . As shown in  FIGS. 5   a  and  5   b  of the drawings, two locking shafts  44  are preferably utilized to selectively secure opposing pairs of locking pins  38 . The locking shaft  44  is comprised of a cam shaped structure that allows for selective release and locking of the plurality of locking pins  38  with respect to the plurality of locking pins  38 . As illustrated in  FIGS. 5   a  and  5   b  of the drawings, the cam shaped structure of the locking shaft  44  is preferably comprised of a generally circular cross sectional shape with a side portion cutaway forming a cutaway that allows the locking pins  38  to pass by as illustrated in  FIG. 5   a  of the drawings. When the locking shaft  44  is rotated the thicker body portion is rotated into the receiver openings and into the respective locking channel  39  of the locking pins  38  thereby preventing removal of the locking pins  38 . As illustrated in  FIG. 5   a  of the drawings, the locking channel  39  preferably has a curved configuration that corresponds to the diameter of the locking shaft  44  to ensure a snug fit when the locking shaft  44  is rotated into the lock position as shown in  FIG. 5   b  of the drawings. 
     A securing lever  40  is connected to the locking shaft  44  to allow for manual rotation of the locking shaft  44 . Each locking shaft  44  includes a securing lever  40 , so as illustrated in the  FIGS. 7   a  through  7   c  of the drawings, it is preferably to have two opposing securing levers  40  attached near the first end  31  of each respective mast section  30 . The securing lever  40  has a locked position preventing release of the plurality of locking pins  38  from the receiver apertures  32  and a release position allowing release of the plurality of locking pins  38  from the receiver apertures  32 . Each of the securing levers  40  is preferably positioned within one of the side channels  34  within the vertical mast to allow for stoppage of the guide wheels  54  when the locking shaft  44  has not fully secure the locking pins  38  or passage of the guide wheels  54  when the locking shaft  44  has fully secured the locking pins  38 . Each of the securing levers  40  preferably includes a biased member  41  (e.g. spring) that forces the securing levers  40  outwardly into the release position as shown in  FIG. 7   a  of the drawings. When the securing lever  40  is positioned within the release position as shown in  FIGS. 7   a  and  7   b  of the drawings, the support platform  50  is prevented from being elevated to an upper mast section  30  above a lower mast section  30 . 
     A locking lever  46  is rotatably attached to the second end  37  of a mast section  30  above a lower mast section  30  as illustrated in  FIG. 9   b  of the drawings. The locking lever  46  is rotatably biased by a spring or other device to be positioned in a locked position and the locking lever  46  is positioned adjacent to the securing levers  40  to prevent movement of the securing levers  40  when in the locked state. The locking lever  46  preferably extends from both sides of the mast section  30  to allow for selective engagement with the securing levers  40  with a single movement. The securing levers  40  each include a centrally located notch  42  that when the locking lever  46  is aligned with (as shown in  FIG. 9   b  of the drawings) the locking lever  46  is allowed to be pivoted into the locked position thereby rotating the locking shaft  44  to the locked position to prevent the locking pins  38  from being released from the receiver apertures  32 . 
     D. Support Platform. 
     The support platform  50  is adapted to be movably connected to the vertical mast.  FIGS. 1 through 3  illustrate an exemplary support platform  50  having a floor  51  and a cage  53 . It can be appreciated that various other configurations may be utilized for the support platform  50  that are capable of lifting and lowering workers and materials. The width of the support platform  50  is the same or less than the width of the support base  20  when in the compact state to allow for passage through narrow areas. It is preferable that the width of the support platform  50  be 30 inches or less. The support platform  50  is constructed of a lightweight material such as but not limited to aluminum. 
     The support platform  50  includes a sliding support  52  extending from the support platform  50  that has a U-shaped structure that is positioned about three sides of the vertical mast. The sliding support  52  includes a plurality of guide wheels  54  that are movably received within the side channels  34  of the vertical mast to allow for relatively free upward and downward movement of the support platform  50  upon the vertical mast. It is preferable to have at least two guide wheels  54  for each of the side channels  34  within the vertical mast, with one of the guide wheels  54  positioned within an upper portion of the sliding support  52  and another of the guide wheels  54  positioned within a lower portion of the sliding support  52  to provide for increased stability and to prevent binding during operation. The diameter of the guide wheels  54  is slightly smaller than the width of the side channels  34  within the vertical mast to limit movement thereof. 
     A drive unit  60  is connected to the support platform  50  that is adapted to elevate and lower the support platform  50  upon the vertical mast. The drive unit  60  may include an actuator (e.g. electric motor, hydraulic motor) or a drive connector  62  to attach an outside actuator (e.g. a drill, hand crank). The drive unit  60  preferably includes an automatic braking system that prevents accidental lowering of the support platform  50  if the actuator should fail or is accidentally removed. The drive unit  60  mechanically engages the track  33  extending along a substantial portion of the length of the vertical mast utilizing a sprocket or other mechanical drive device. U.S. Pat. No. 6,981,573 to Nickel illustrates an exemplary drive unit  60  and is hereby incorporated by reference herein. 
     An emergency winch  12  is attached to the support base  20  that has a tether connectable to an emergency connector  13  attached to the support platform  50  to allow for an individual at the base of the present invention to lower the support platform  50  where the operator of the present invention is unable to. The emergency winch  12  draws the support platform  50  downwardly overcoming the braking force applied by the automatic breaking system within the drive unit  60  thereby forcing the support platform  50  to lower. 
     At least one mast storage device  58  extends outwardly from the support platform  50  as illustrated in  FIGS. 1 through 3  of the drawings. The plurality of mast sections  30  are removably connectable to the mast storage devices  58  for storage of the plurality of mast sections  30  during non-use of the present invention, during assembly of the vertical mast and during disassembly of the vertical mast. The mast storage devices  58  are comprised of an extended bracket structure with an upper plate that includes a plurality of storage apertures  59  that receive the corresponding locking pins  38  from each mast section  30 . As illustrated in  FIG. 1  of the drawings, only two of the locking pins  38  from each mast section  30  are required to be inserted into the mast storage device  58  thereby allowing two or more mast sections  30  to be received and stored upon each of the mast storage devices  58 . The mast storage devices  58  are preferably attached to the lower portion of the support platform  50  and extend outwardly on opposing sides of the vertical mast as illustrated in  FIGS. 1 through 3  of the drawings. 
     E. Operation of Preferred Embodiment. 
     In use, the user transports the present invention in the compact storage position ( FIG. 1 ) to a desired location where working at an elevated height is required (e.g. interior of a building). The user then removes the outer legs  24  and attaches them to the inner legs  22  of the support base  20 . 
     The respective adjustment members  26  for each of the outer legs  24  are lowered by rotating the adjustment members  26  until the caster wheels  21  are no longer supporting the present invention. 
     The support platform  50  will not be allowed to move upwardly unless all of the finger members  55  are allowed to freely pass through and out of the guide members  70 . Free movement of the finger members  55  within the guide members  70  requires an upward pressure to be applied to each of the adjustment members  26  causing the first engaging member  84  to inwardly push the second engaging member  86  thereby causing the elongated shaft  88  to depress the corresponding locking detent  57  sufficiently so that the locking detent  57  does not catch upon the lower end of the corresponding guide member  70  as illustrated in  FIGS. 13   b  and  13   c  of the drawings. If any of the legs are not supporting weight, the support platform  50  will not be allowed to be released since at least one of the finger members  55  will be captured within the corresponding guide member  70  by the corresponding locking detent  57 . The user will have to adjust the adjustment member  26  until each of the adjustment members  26  has sufficient and substantially equal weight supported by the same thereby causing the corresponding elongated shaft  88  to depress the corresponding locking detent  57 . The user may test whether all of the finger members  55  are released by attempting to lift the support platform  50  upwardly a small distance. 
     After the user has tested the stability of the support base  20 , the user may then enter the support platform  50  and begin assembly of the vertical mast with the mast sections  30  as shown in  FIG. 2  of the drawings. To assemble the vertical mast, the user removes the proper mast section  30  from the mast storage device  58  while they are positioned within the support platform  50  and positions the second end  37  of the mast storage device  58  upon the first end  31  of the base mast section  30 . The locking pins  38  extend into the receiver apertures  32  and the user then rotates the locking lever  46  thereby allowing rotating of the securing levers  40 . With the locking lever  46  centrally located and aligned with the notch  42  within the corresponding securing levers  40 , the user then rotates the securing levers  40  to rotate the locking shaft  44  to lock the locking pins  38  within the receiver apertures  32 . The locking lever  46  is rotated back to the locked position to prevent movement of the securing levers  40  thereby ensuring the corresponding mast sections  30  will remain securely connected. The user is able to operate the drive unit  60  to elevate the support platform  50  onto the last assembled mast section  30  to allow for attachment of another mast section  30  above thereof. The process is continued for each of the remaining mast sections  30  until the vertical mast is completed as illustrated in  FIG. 3  of the drawings. The user may then travel along the vertical mast with the support platform  50  as desired to perform their work. When the work is completed, the user then reverses the process by releasing the locking lever  46 , releasing the securing levers  40  and removing each of the mast sections  30  (the sliding support  52  must be positioned beneath the connection point to be released before releasing the same). This process continues until the support platform  50  is fully lowered and all of the mast sections  30  have been removed and positioned within the mast storage device  58  as shown in  FIG. 10  of the drawings. Once the finger members  55  are all fully extended into the guide members  70 , the corresponding lower biased units  72  are corresponding forced downwardly by the same thereby lowering the flanged end member  74  to the lower broader portion of the slot  25  within the partition member  23  thereby allowing removal of the corresponding outer leg  24  (if the lower biased unit  72  is not fully lowered, then the corresponding outer leg  24  cannot be removed). Once the outer legs  24  are positioned in the storage position, the user may then transport the present invention to storage or another work location. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described above. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety to the extent allowed by applicable law and regulations. In case of conflict, the present specification, including definitions, will control. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive. Any headings utilized within the description are for convenience only and have no legal or limiting effect.