Patent Abstract:
The present invention is a powered lift platform including a platform, at least one guide rail section in operative contact with the platform, each of the at least one guide rail sections comprising at least one guide rail and in which a first end of each of the guide rail sections is configured to removably attach to a second end of a second guide rail section. The invention also includes a lift mechanism supported by the platform, a lift guide in operative contact with the lift mechanism and attached to the upper portion of the upper guide rail, a power supply to operate the lift mechanism. In a preferred embodiment, at least one wheel is operatively attached to the powered lift platform. Also presented is a method for securing the powered lift platform to a columnar-like support. Also presented is an extendable standoff.

Full Description:
FIELD OF THE INVENTION 
     The field of the invention relates generally to powered lift devices, particularly to powered hunting tree stands, and more particularly to portable hunting tree stands. 
     BACKGROUND OF THE INVENTION 
     Tree stands are well known hunting devices used to elevate one or more hunters to allow them a wider range of vision over the area in which they are hunting. One problem associated with tree stands in general is that they require the user, typically a hunter with a weapon, to physically climb up from the ground onto the tree stand platform. This can be an awkward task as the hunter is most likely carrying a weapon such as a rifle, shotgun, or bow and arrow as well as one or more food and drink containers. More importantly, hunters who are disabled to the point where physically climbing up into or down from a tree stand is either extremely difficult or impossible, are deprived of an important and enjoyable part of the hunting experience. 
     One other important problem of tree stands in the prior art is that they are often permanent structures. Because elevated tree stands are typically placed in trees or permanent structures, they are difficult to easily move from one location to another. Consequently, they are often left in place and exposed to weathering and other destructive effects that eventually lead to the deterioration of the tree stand. 
     The prior art contains examples of mechanized tree stands and powered lifts. U.S. patent application Nos. 2004/0083660 to Atkins, 2003/0000769 to Pyle, 2002/0139613 to Hardy are examples of recent publications disclosing portable and elevating hunting stands. Also included in this group is U.S. Pat. No. 5,862,827 to Howze. While the devices disclosed in these publications are all portable and capable of mechanized elevation, in each case the user must climb a ladder to reach the elevated platform. Thus, even though the platforms disclosed can be elevated, they provide no benefit to either a disabled hunter or one overly burdened with equipment who is attempting to climb into the platform. 
     U.S. patent application No. 2003/0178251 to Hewitt and U.S. Pat. No. 6,471,269 to Payne, U.S. Pat. No. 5,803,694 to Steele, U.S. Pat. No. 4,602,698 to Grant disclose tree stands which provide mechanized elevation for the user. In addition, U.S. Pat. No. 3,681,565 to Fisher discloses a suspended welding booth which mechanically raises the welder to a suspended position against a wall or other vertical structure. However, a review of these publications reveals an additional problem, namely the stability of the suspended platform. In each publication, the suspended platform, chair or booth is lifted off the ground and depends solely on the structural stability of a suspension system for safe support rather than using the actual ground as a foundation to support the elevated user. 
     U.S. Pat. Nos. 2,943,708 to Sasgen and U.S. Pat. No. 4,183,423 to Lewis both disclose mechanized hoists that remain placed on the ground or floor. However, both have the lift mechanism positioned off the elevating platform requiring someone other than the rider to raise and lower the platform. U.S. Pat. No. 5,595,265 to Lebroquy discloses a powered vertical lift but its configuration severely limits the height to which the lift may ascend. In addition, it fails to provide lateral stability to the suspended lift. 
     Therefore, there is a need in the field for a portable powered tree stand that is easily maneuverable, provides mechanized elevation to the user, and provides stability to a platform when it is the raised position. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a powered lift platform that includes a platform, at least one guide rail section in operative contact with the platform, each of the at least one guide rail sections comprising at least one guide rail and in which a first end of each of the guide rail sections is configured to removably attach to a second end of a second guide rail section, a lift mechanism supported by the platform, a lift guide in operative contact with the lift mechanism and attached to the upper portion of the upper guide rail, a power supply to operate the lift mechanism. In a preferred embodiment, at least one wheel is operatively attached to the powered lift platform. The present invention further comprises a method of securing the powered lift platform to a vertical or sloping support. The present invention also includes an extendable standoff to adjustably support a device against a vertical or sloping support. 
     An object of the invention is to provide a powered or mechanized lift operated by a user positioned on the platform. 
     A second object of the invention is to provide a powered lift platform that is positioned on the ground or floor. 
     A third object of the invention is to provide a powered lift platform with lateral stability when elevated off the ground. 
     An additional object of the invention is to provide a powered lift platform in which the user may remain on the platform to secure the device to a vertical structure such as a tree or column. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The nature and mode of the operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing Figures, in which: 
         FIG. 1  depicts a perspective view of the powered lift platform of the present invention; 
         FIG. 2  is a magnified perspective view of the lower slider adjustment of the present invention; 
         FIG. 2   a  is a top view taken along line  2 A- 2 A of  FIG. 2  showing the lower slider adjustment; 
         FIG. 3  is a magnified perspective view of the upper slider adjustment and cable break stop of the present invention; 
         FIG. 3   a  is a top view of the upper slider adjustment and cable break stop of the present invention; 
         FIG. 3   b  is a magnified perspective view of an alternate embodiment of the upper slide adjustment; 
         FIG. 3   c  is a top view of the alternate embodiment of the upper slide adjustment; 
         FIG. 4  is a rear view of the powered lift platform of the present invention; 
         FIG. 4   a  is a rear view of the powered lift platform depicting the activation of the cable break stop by the broken cable; 
         FIG. 4   b  is a magnified side view of the adjustment assembly for the base plate of the present invention; 
         FIG. 5  is a side view of the powered lift platform of the present invention; 
         FIG. 5   a  is a side view of the present invention in which the safety lock is activated; 
         FIG. 6  depicts an alternate embodiment of the lift guide used to lift the platform in the present invention; 
         FIG. 6   a  is a magnified perspective view of the alternate lift guide seen in  FIG. 6 ; 
         FIG. 7  demonstrates a second alternate embodiment of the lift guide for the powered lift platform of the present invention; 
         FIG. 7   a  is a magnified perspective view of the second alternate lift guide for the powered lift platform of the present invention; 
         FIG. 8  is a top perspective view of the grippers of the present invention; 
         FIG. 8   a  is an exploded top perspective view of the grippers of the present invention; 
         FIG. 9  is a side perspective view of the present invention attached to an upright support; 
         FIG. 10  is a side view of the present invention in a disassembled mode for towing; 
         FIG. 11  is a side perspective view of an alternate embodiment of the disassembled mode; 
         FIG. 12  is an exploded view of the assembly arrangement of the alternate disassembled mode; and, 
         FIG. 12   a  is a side perspective view of the constructed assembly arrangement seen in  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred embodiments, it is understood that the invention is not limited to the disclosed embodiments. The present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 
     Adverting to the drawings,  FIG. 1  depicts a perspective view of powered lift platform  10 . Carriage  80  comprises the movable component of powered lift platform  10  and includes at a minimum platform  11 . Carriage  80  also includes other components found in various embodiments described and shown as attached directly or indirectly to platform  11 . Platform  11  is shown supporting power box  12  which houses a battery (not shown) and holds a battery switch  35  that is used as a power control. In a preferred embodiment, switch  35  is rotated in one direction to power platform  11  upward and rotated in the opposite direction to move platform  11  down. A suitable battery is a 12 volt all glass mat battery made by Universal Power Group. In addition, an AC inverter may be used. Preferably, a solar trickle charge device may be attached to the battery to constantly maintain battery charge when power lift platform  10  remains outdoors. In the preferred embodiment shown, seat  43  is supported by power box  12 . Also not shown in  FIG. 1  is the housing for winch  32  which is secured to platform  11  and used to raise and lower platform  11 . Stop lever  28  includes safety stop blade  28   a  and is also attached to a second safety stop blade  28   a  (not shown in  FIG. 1 ) by means of safety axle  30 . Stop lever  28  and safety stop blades  28   a  are welded or otherwise securely attached to axle  30  as shown in  FIGS. 3 and 3   a . Guide rails  13  are shown in operative attachment with platform  11  which is described in detail below and seen in  FIGS. 2-3   c . By operative attachment or operative contact is meant the contacting of carriage  80 , platform  11  or a part of or a component of power lift platform  10  with guide rails  13  during at least a portion of the movement of platform  11  along guide rails  13 . Although a guide rail section having one guide rail  13  may be used to raise and lower platform  11  or carriage  80 , in the preferred mode shown in  FIG. 1 , pairs of guide rails  13  comprise a guide rail section. 
     In a preferred embodiment, guide rails  13  are approximately 6 feet in length. In a more preferred embodiment, more than one set of guide rails is used to allow platform  11  to be pulled to a greater heights if desired. In the more preferred embodiment shown in  FIG. 1 , guide rail inserts  14  can be inserted into guide rail sockets  15  to enable platform  11  to be moved efficiently up and down more than one section or set of attached guide rails  13 . Alternatively, sets of guide rails  13  can be bolted together or attached by alternate means well known in the art to enable them to be placed into an upright position. 
     In a preferred embodiment, guide rails  13  include attached standoffs or grippers  16  that rest against a vertical support such as a tree, lamp post, pole or other vertical support (not shown in  FIG. 1 ). In a preferred embodiment, grippers  16  include teeth  17  to allow a more secure hold against vertical supports such as tree trunks. In a more preferred embodiment, gripper adjustments  18  are provided to extend or retract grippers  16  from or toward guide rails  13 . Use of gripper adjustment  18  allows guide rails  13  to be positioned in a more upright (nearly vertical) orientation even if the vertical support is itself in a comparatively more sloping (non-vertical) position. 
     Powered lift platform  10  is operated by a lift mechanism attached to platform  11  and placed in operative contact with a lift guide that provides lift support for the lift mechanism and/or lift guide for the lift mechanism.  FIGS. 1 ,  2 ,  2   a ,  4 ,  4   a ,  5 , and  5   a  show one type of lift mechanism, namely winch  32  attached to platform  11  through winch frame  32   a . Cable  33  is attached to winch  32  and to cable anchor  21  at an anchor point preferably located at the top of the highest guide rail  13  and acts as the lift guide for winch  32 . The anchor point is defined as the location where the lift guide (cable  33  in the embodiment shown in  FIG. 1 ) is secured to guide rail section  13 . In a preferred embodiment, a second cable anchor  21   a  is placed on a lower guide rail  13  section to enable platform  11  to be raised sufficiently on lower guide rails  13  to allow the operator to more easily attach an additional guide rail section  13  to the lower guide rail  13  section. Platform  11  is transported along guide rails  13  as winch  32  winds or unwinds cable  33 . Preferably, winch  32  is operated from platform  11  using switch  35  as it is raises or lowers platform  11  along guide rails  13 . Switch  35  may be located on power box  12  and is connected to the battery and winch  32 . In an alternate embodiment, switch  35  and power cord  34  may be located proximate to the ground to allow the operator to remain on the ground while operating powered lift platform  10 . It will be recognized that in this alternate embodiment, switch  35  and power cord  34  may be a hand-held control used by the operator positioned on platform  11 . 
     Also shown in  FIG. 1  are safety rails  44  which extend along the sides and front of platform  11 . In one embodiment, rails  44  comprise two sets of rails each possessing two risers supporting a crosspiece. Detachable front rail  44   a  links the two sets of side rails. Base plates  23  are attached to the bottom of each of guide rail sections  13  and provide support for guide rail sections  13  against the ground. 
       FIG. 2  is a magnified perspective view of lower slide adjustment  27 . Bolt  27  is shown extending through lower lever arm  27   b . Lower press pad  27   c  is attached to lower lever arm  27   b . Lower guide pad  27   d  is attached to lower press pad  27   c . As bolt  27  is tightened, it draws lower guide pad  27   d  (attached to lower press pad  27   c ) against the internal side of guide rail section  13  by pivoting lever arm  27   b  around pivot point  27   a .Preferably, lower press pad  27   c  is made from a metal such as is used in typical angle iron and lower guide pad  27   d  is made from a plastic with some resilience such as Teflon to reduce the friction between lower guide pad  27   d  and the internal side of guide rail  13 . Pivot point  27   a  can be a bolt rod or similar device that is placed through lever arm  27   b  as shown to allow it to pivot or rotate. Gap  36  is established between lower lever arm  27   b  and winch frame  32   a  using lower adjustment spacer  27   e  to allow lower lever arm  27   b  to rotate freely. Gap  36  is exaggerated in  FIG. 2  for clarity.  FIG. 2   a  is a top view of lower slide adjustment  27 . Ultimately, this lower adjustment mechanism presses lower guide pad  27   d  against guide rail  13  to help stabilize platform  11  against guide rails  13  as it is raised and lowered. Also seen in  FIG. 2  are wheels  22  operatively attached to powered lift platform  10 . By operative attachment is meant that at least one wheel  22  is attached to powered lift platform  10  to allow it to be towed or otherwise moved using a wheel, tire or equivalent device. In the embodiment shown, two wheels  22  are attached to guide rails  13  by means of wheel attachments  22   a . In an alternate embodiment, wheels  22  may be attached to platform  11 .  FIG. 2  also shows base plate prong  23 a which is positioned into the ground to further support power lift platform  10 . 
       FIG. 3  is a magnified perspective view of upper slide adjustment  26 . In this preferred embodiment, the head of bolt  26  is placed between upper lever arm  26   b  and cable stop frame  37   a  and extends through cable stop frame  37   a . In the embodiment shown, cable stop frame  37   a  is threaded. In an alternate embodiment, a nut is secured to cable stop frame  37   a  to secure bolt  26 . As bolt  26  is tightened or loosened, it decreases or increases pressure onto upper press pad  26   c , attached to upper lever arm  26   b  and upper guide pad  26   d , attached to upper press pad  26   c . Ultimately, this enables pressure to be applied through upper guide pad  26   d  against the internal surface of guide rail  13 . In this preferred embodiment, the end opposite the head of bolt  26  extends through cable stop frame  37   a  and is not “mushroomed” by pressing against upper press pad  26   c . It should be recognized that this preferred embodiment can be used for the lower slide adjustment  27  and that the arrangement described above for lower slide adjustment  27  can be used for upper slide adjustment  26 . 
       FIG. 3   a , taken along line  3   a - 3   a  in  FIG. 3 , is a top view of upper slider adjustment  26 . Similar to lower slide adjustment  27  described above, upper press pad  26   c  may be made from angle iron while upper guide pad  26   d  is made from a plastic such as Teflon to reduce friction with the internal surface of guide rail  13 . 
       FIG. 3   b  shows depicts an alternate embodiment in which upper guide pad  26   d  is replaced by bearings  26   f . Bearings  26   f  are biased against the internal surface of guide rail section  13  to reduce friction between platform  11  and guide rail section  13  as platform  11  moves along the guide rail section  13 . Bearings  26   f  may also be used in lower slide adjustment  27 .  FIG. 3   c  is a top view of the embodiment seen in  FIG. 3   b.    
     Also shown in  FIGS. 3 and 3   a  is cable break stop  31 . Cable break stop  31  is attached to cable stop frame  37   a  at pivot  38  and is functionally associated with cable  33 . By functional association is meant that the position of cable break stop  31  in relation to platform  11  and lock stop  19  or ladder step  20  is dependent on whether cable  33  is intact (or taut) or broken (or slack) as described below. When cable rest  39  of cable break stop  31  contacts cable  33  above pivot  38 , cable break stop  31  has insufficient length to reach to ladder step  20 , but can extend to ladder step  20  when it rotates to a more horizontal orientation. During operation, cable  33  is arranged to contact cable rest  39  on the opposite side from pivot  38  and cable break stop  31  is orientated so cable rest  39  is rotated away from ladder step  20 . As winch  32  winds cable  33 , cable stop  40  prevents cable  33  from losing contact with cable rest  39  as winding cable  33  travels back and forth along the spool of winch  33 . Cable break stop  31  functions to stop platform  11  from falling should cable  33  break or become slack. In the situation when platform  11  is stopped and cable  33  becomes slack, cable break stop  31  continues to rest against cable  33 . As cable  33  becomes taut when platform  11  starts to move, the snapping action will tend to push cable break stop  31  away from cable  33 . Cable pivot stop  46 , preferably located over pivot  38  prevents cable break stop  31  from rotating too far and ensures the cable rest  39  contacts cable  33 . 
       FIG. 4  is a rear view of powered lift platform  10  depicting cable rest  39  (not shown in  FIG. 4 ) of cable break stop  31  contacting cable  33  as platform  11  is being raised.  FIG. 4   a  demonstrates the action of cable break stop  31  after cable  33  breaks causing platform  11  to fall. In the event of such a break, while platform  11  falls, cable rest  39  will rotate until it contacts and rests against cable break frame  37   a  thus preventing further rotation in that direction. Simultaneously, during the fall of platform  11 , the opposite end of cable break stop  31  rotates until it contact ladder step  20  (or lock stop  19  if cable break stop  31  is oriented toward the opposite side). Because cable break frame  37   a  prevents rotation of the cable rest  39  end of cable break stop  31  and ladder step  20  prevents rotation of the opposite end of cable break stop  31 , platform  11  is prevented from falling by the wedged position of cable break stop  31  created during the fall.  FIGS. 4 and 4   a  also show paired lower slide adjustment  27  and paired upper slide adjustment  26   b  each attached to opposite sides of platform  11 . 
       FIG. 4   b  depicts an adjustment assembly for base plate  23 . Telescoping slide  23   b  includes adjustment holes  23   d  and moves within guide rail section  13 . To provide more level support for power lift platform  10  on uneven ground, telescoping slide  23   b  of each guide rail section  13  can be separately adjusted by moving adjustment holes  23   d  to a desired level and then securing them in place by pin  23   c  which is inserted through a hole in guide rail section  13  and through an appropriate adjustment hole  23   d  to provide a firm support for each base plate  23  whether on even or uneven ground. In one embodiment, adjustment holes  23   d  are placed approximately one inch apart, but different distances may be used if desired. 
       FIG. 5  is a side view demonstrating the structure of safety stop lever  28 . Safety stop lever  28  and stop axle  30  pivot is seen in  FIG. 3  to turn paired stop blades  28   a . Stop blocks  29  are positioned on each side of power box  12  to prevent complete rotation of stop lever  28 . Stop lever  28  functions as an emergency brake if platform  11  should unexpectedly fall. As platform  11  is raised up along guide rails  13 , stop blades  28   a  contact the bottoms of safety stop  19  and ladder steps  20  located on opposite sides of guide rails  13 . The continued upward movement of platform  11  forces safety lever  28 , safety blades  28   a  and axle  30  to rotate. After clearing safety block  19  and ladder step  20 , safety lever  28  rotates back to contact safety stop blocks  29 . It will be easily recognized that if the operator holds safety lever  28  up, safety blades  28   a  rotate out of the contact path to prevent the intermittent contact with successive safety stops  19  and ladder steps  20  as platform  11  is raised or lowered. It will also be recognized that if platform  11  should fall, safety blades  28   a  will contact the upper surface of either or both of safety stop  19  or ladder step  20 . Because safety block  29  is positioned in the rotational path of safety lever  28 , its presence prevents further rotation of safety blades  28   a  off both safety stop  19  and ladder step  20  thus holding platform  11  and preventing the fall from continuing as seen in  FIG. 5   a . Ladder steps  20  can also be used to climb down from platform  11  when it is stopped in a raised position off the ground. 
       FIGS. 5 and 5   a  also show a preferred embodiment in which switch  60  is positioned preferably on carriage  80 . Carriage  80  is defined as the entire movable component of powered lift platform  10  that moves up and down guide rail section(s)  13 . Switch  60  is a type of normally open, normally closed switch such that when activated, it shuts off power to the up drive of winch  32  or other powered lift mechanism and maintains power to the down drive. Switch  60  is activated by actuator  61  (see  FIG. 9 ) placed toward the top of upper guide rail section  13  so that as platform  11  reaches an upper limit (such as when cable  33  is wound almost completely onto winch  32 , switch  60  is activated by actuator  61  to prevent platform  11  from moving further up guide rail sections  13  and allows platform  11  to move only down guide rail sections  13 . In a more preferred embodiment, lower actuator  61   a  is movably attached to the lowest guide rail section  13  to prevent platform  11  from being lifted too high before upper guide rail section  13  is attached. After attachment, lower actuator  61   a  is moved away from the lift path by hinges or other means known in the art. 
       FIG. 6  depicts an alternate means of lifting platform  11  up and down along guide rails  13 .  FIG. 6  shows gear-tooth rails  47  extending behind platform  11  which supports gear motor  48  (not shown in  FIG. 6 ) and anchored at the top of guide rail section  13 . As seen in  FIG. 6   a , gear motor  48  operates gears  49  to rotate them along gear-toothed rails  47 . Because gear motor  48  is attached to platform  11 , platform  11  is raised or lowered along gear-toothed rails  47  according to the direction of rotation of gears  49  Although two gear-tooth rails  47  are shown in  FIG. 6 , it will be recognized that one or more than two gear-tooth rails  47  may be used although the use of only one gear tooth rail  47  is less preferred. Preferably, gear-toothed rails  47  are used with guide rails  13  although it will be recognized by those skilled in the art that gear-toothed rails  47  may replace guide rails  13  to supply both lift guide and lifting functions to powered lift platform  10 . 
       FIG. 7  demonstrates a second alternate embodiment of the lift mechanism for powered lift platform  10 . Helical carry rod  50  extends from a base or bottom transverse bar  45  to an anchor point  21 .  FIG. 7   a  shows ball screw mechanism  51  attached to platform  11  and operated by ball screw motor  52  to traverse up and down helical carry rod  50  thereby lifting platform  11  up and down along helical carry rod  50 . Mechanisms able to convert rotational movement to vertical movement are well known in the art. 
       FIG. 8  is a top perspective view of grippers  16  adjustably attached to guide rails  13 . As will be seen below, grippers  16  having at least one extension from guide rail section  13  are used to support powered lift platform  10  against an upright support such as a tree, pole, lamppost or similar device. In a preferred embodiment, gripper  16  includes teeth  17  and a pair of gripper extensions  18   c  attached to the v-shaped gripper  16  and containing a plurality of position holes  18   d . In an alternate embodiment, gripper  16  may be U-shaped. Gripper  16  is arranged to extend from and retract into gripper adjustment sleeve  18   a . In operation, gripper  16  is pulled from gripper extensions  18   c  and held in a desired position against an upright support by inserting gripper adjustment pin  18   b  (“pin  18   b ”) through one of position holes  18   d  and restraining hole  18   e . It will be recognized that each of the plurality of grippers  16  can be adjusted individually to establish a stable position for powered lift platform  10  even if the upright support is not straight or is at a sloping angle relative to the ground. In a preferred embodiment, transverse bar  45  extends between guide rails  13  to provide lateral rigidity between the paired guide rails  13   
       FIG. 9  shows power lift platform  10  supported against upright support  42 , in this case tree  42 . Straps  41 , preferably ratchet straps  41 , are seen wrapped around tree  42  and attached to both ends of transverse bar  45 . Powered lift platform  10  is supported substantially upright by placing base plates  23  as close to tree  42  as possible and positioning power lift platform  10  upright near or against tree  42 . Grippers  16  are extended to the desired length to produce a preferred vertical or near vertical position. After setting gripper  16  positions on lower guide rails  13 , ratchet straps  41  are wrapped around tree  42 , connected to gripper  16 , or preferably transverse bar  45 , and tightened. In a preferred embodiment, cable  33  is attached to lower cable anchor  21   a  and platform  11  is raised to a desired height. A second set of guide rails  13  is attached to the first or bottom set of guide rails  13  by, for example, inserting guide rail inserts  14  into guide rail sockets  15 . The two sets of guide rails  13  may also be attached by bolts, hinges, or other suitable attachment devices known to those skilled in the art. Before attaching this second set, cable  33  is attached to cable anchor  21 . After attachment of upper guide rails  13  to lower guide rails  13 , winch  32  is operated to move platform  11  up guide rails  13 . At a suitable position(s), platform  11  is stopped, gripper  16  is adjusted and additional ratchet straps  41  are wrapped around tree  42  and attached at both ends of gripper  16 , or preferably transverse bar  45 , as shown in  FIG. 9 . Once a sufficient number of grippers  16  are attached to tree  42 , powered lift platform  10  can be safely operated to move up and down the plurality of guide rails  13 . 
       FIG. 10  depicts powered lift platform  10  in a disassembled mode with two wheels  22  and two sets of guide rails  13  secured to each other and towed by an individual user. Alternately, a towing attachment may be used to tow powered lift platform  10  using such vehicles as all terrain vehicles, trucks, cars, or other suitable equipment. Hold down straps  70  are used to hold separate guide rails  13  components together and to hold safety rails  44  onto platform  11 . Ratchet straps  41  may be used as hold down straps. 
       FIGS. 11 ,  12  and  12   a  depict a preferred design of the disassembled mode in which safety stops  19  and ladder steps  20  of one guide rail section  13  align with grippers  16  of a second guide rail section  13 .  FIG. 11  is a perspective view showing this preferred design.  FIG. 12  is exploded view of this preferred embodiment in which ladder joiner  71  and safety stop joiner  72  each have a joining hole  71   a  and  72   a , respectively. Ladder joiner  71  is inserted through ladder step  20  into gripper adjustment sleeve  18   a  and is held in position with pin  71   b  inserted through joining hole  71   a  and ladder pin hole  71   c . Similarly, safety stop joiner  72  is inserted through safety stop  19  into gripper adjustment sleeve  18   a  and is held in position with pin  72   b  which extends through safety stop joining hole  72   a  and safety stop pin hole  72   c . In this embodiment, the two guide rail sections  13  are then held securely in place by joining pins  71   b  and  72   b.    
     Thus it is seen that the objects of the invention are efficiently obtained, although changes and modifications to the invention should be readily apparent to those having ordinary skill in the art, which changes would not depart from the spirit and scope of the invention as claimed.
       10  powered lift platform     11  platform     12  power box     13  guide rails     14  guide rail inserts     15  guide rail sockets     16  gripper     17  gripper teeth     18  gripper adjustment     18   a  gripper adjustment sleeve     18   b  gripper adjustment pin     18   c  gripper adjustment extension     18   d  position hole     18   e  attachment hole     19  safety stop     20  ladder step     21  cable anchor/anchor point     21   a  lower cable anchor     22  wheels     22   a  wheel attachment     23  base plate     23   a  base plate prongs     23   b  telescoping slide     23   c  telescoping slide pin     23   d  telescoping slide adjustment hole     26  upper slide adjustment/bolt     26   a  upper adjustment pivot     26   b  upper adjustment lever arm     26   c  upper adjustment press pad     26   d  upper adjustment guide pad     26   f  bearing     27  lower slide adjustment/bolt     27   a  lower adjustment pivot     27   b  lower adjustment lever arm     27   c  lower adjustment press pad     27   d  lower adjustment guide pad     27   e  lower adjustment spacer     28  safety stop lever     28   a  safety stop blade     29  safety stop block     30  safety stop axle     31  cable break stop     32  winch     32   a  winch frame     33  cable     33   a  cable hook     34  power cord     35  switch     36  gap     37  cable stop frame     38  cable break stop pivot     39  cable rest     40  cable stop     41  ratchet straps     42  tree     43  seat     44  safety rails     44   a  detachable front rail     45  transverse bar     46  cable pivot stop     47  gear-toothed lift rails     48  gear motor     49  gear     50  helical carry rod     51  ball screw mechanism     52  ball screw motor     60  switch     61  actuator     61   a  lower actuator     70  strap     71  ladder joiner     71   a  ladder joiner hole     71   b  ladder joiner pin     71   c  ladder pin hole     72  safety stop joiner     72   a  safety stop joiner hole     72   b  safety stop joiner pin     72   c  safety stop pin hole

Technology Classification (CPC): 0