Abstract:
A modular adjustable hoist has a winch and a cable for hoisting an object. An electric motor is coupled to the winch for winding and unwinding the cable. An adjustable frame is used for securing the winch to a support or in a free standing position. The support can include a door frame, a wall, and an automotive vehicle. Legs can be attached to the adjustable frame for providing stability to the hoist for use with or without the structural support.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a modular adjustable hoist that is portable and can be utilized in multiple configurations. 
   BACKGROUND OF THE INVENTION 
   Devices for hoisting cargo are well known in the art. Often these devices take up a substantial amount of room and are very immobile and heavy. A hoist typically includes a winch having a cable wound on a drum which is typically driven by a reversible electric motor. The cable usually has a hook on it for attaching to an object to be moved from one location to another. 
   Despite numerous hoist designs on the market today, there continues to be a need for a relatively compact, lightweight, portable, and adjustable hoist for a typical homeowner or business person needing to lift heavy objects up flights of stairs, into a cargo van, or into a free standing position off the ground. 
   SUMMARY OF THE INVENTION 
   An apparatus according to the present invention having different configurations for hoisting objects in a variety of locations. A modular adjustable hoist with a winch has a cable wound on a drum and has an attachment member at one end of the cable to attach to an object. An electric motor is coupled to the drum for winding and unwinding the cable and an adjustable frame for securing the winch to a structural support. In the first aspect, the structural support can be a door frame. The adjustable hoist is secured to the door frame for lifting a heavy object up a flight of stairs. The adjustable hoist has first and second outer cylindrical members with two inner cylindrical members internal to the outer members. The first and second inner cylindrical members are telescopically disposed in each of the outer cylindrical members, such that the inner cylindrical members can retract inwardly and extend outwardly from the first and second ends of the outer cylindrical members. 
   A pair of end blocks are attached to the inner cylindrical members, and can be secured against the sides of the door frame in a locked position to provide support for the adjustable hoist. A pair of vertical extensions are attachable to the end blocks. The vertical extensions rest on the floor underneath the door frame to provide further support of the adjustable hoist. 
   A second aspect uses sidewalls of a doorway as the structural support. This is a variation of the door frame configuration in that the modular adjustable frame can be used in a doorway, without actually being wedged into the door frame itself. A pair of horizontal extensions are attached to the end blocks and butted up against a vertical surface next to the door frame so that the load can be pulled up a stairway with a winch wherein the forces are transmitted through the horizontal extensions into the wall next to the door frame. 
   In a third aspect, the modular adjustable hoist can be used in a truck or a cargo van to pull heavy loads up into the bed of the vehicle. The modular adjustable hoist is basically set up with the same configuration as the door frame configuration except for an additional leg extension attached to each of the vertical leg extensions. When utilizing a cargo van, a bolt with a pad on one end is attached to each end block and can be adjusted inwardly or outwardly relative to the end blocks for pressing up against the roof of the cargo van to provide additional stability for the hoist. 
   In a fourth aspect, the modular adjustable hoist can be configured into a free standing lift. The adjustable frame is rotated 90 degrees and four leg extensions are attached to the end blocks. Each leg is at an oblique angle relative to each other, similar to a saw horse configuration, for providing stability to the adjustable hoist when lifting heavy objects off of a surface. 
   The advantage of this invention is that a hoist is designed in a relatively compact, lightweight, portable and adjustable way so that a typical homeowner or business person can lift heavy objects up flights of stairs or into a cargo van. This hoist is easy to set up in any configuration by one individual. 
   Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
       FIG. 1  is a perspective view of a modular adjustable hoist according to the present invention; 
       FIG. 2  is a bottom elevational view of the jack screw mechanism for the modular adjustable hoist; 
       FIG. 3  is a perspective view of a first aspect of a modular adjustable hoist mounted in a door frame configuration; 
       FIG. 4  is a perspective view of a second aspect of a modular adjustable hoist mounted in a doorway configuration; 
       FIG. 5  is a perspective view of a third aspect of a modular adjustable hoist mounted in a vehicle configuration; 
       FIG. 6  is a perspective view of the third aspect of the modular adjustable hoist lifting a load into a cargo van; and 
       FIG. 7  is a perspective view of a fourth aspect of a modular adjustable hoist in a free standing configuration. 
   

   DETAILED DESCRIPTION 
   A modular adjustable hoist according to the present invention in various aspects is illustrated in  FIGS. 1–7 . The modular adjustable hoist  10  is shown in  FIG. 1 . The hoist  10  has a winch  12  with a cable  14  and an attachment means  16  on the end of the cable  14 . The hoist  10  is driven by an electric motor  18  which is used for lifting or lowering an object. A control, such as Dayton controller  20 , is used to control the motor  18 . The modular adjustable hoist  10  has a first outer cylindrical member  22  and a second outer cylindrical member  24 . These outer cylindrical members  22 ,  24  can be tubes made of various materials depending on the stress induced into the apparatus in the loaded condition. If the load is relatively low, the hoist  10  can be made of aluminum and for heavier loads a high carbon steel material would be more appropriate. There are two inner cylindrical members inside each outer cylindrical member  22 ,  24 . A first inner cylindrical member  26  and a second inner cylindrical member  28  telescopically engages with outer cylindrical member  22 . A first inner cylindrical member  30  and a second inner cylindrical member  32  telescopically engages with outer cylindrical member  24 . Inner cylindrical members  26  and  30  are mechanically attached to one end block  34  and inner cylindrical members  28  and  32  are mechanically attached to the another end block  36 . Both end blocks  34 ,  36  have a protective cushion  38 ,  40  on an outer wall so that when the adjustable hoist  10  is extended into sidewalls of a door frame  60 , the hoist  10  and the door frame  60  are protected. The protective cushions  38 ,  40  can be made of any soft material such as a rubber, cloth, or foam. The protective cushions  38 , 40  are held in position by top plates  41  and  43 . Top plates  41 , 43  are connected to the end plates  34 , 36  by fasteners such as screws, bolts, or rivets. The protective cushions  38 , 40  are trapped between the end blocks  34 , 36  and the top plates  41 , 43 . 
   Each end block  34 ,  36  has a dowel pin pressed into an end wall  42 ,  44  to allow leg extensions  46  and  48  to slide over the dowel pins  42 ,  44  to provide vertical support for the adjustable hoist  10  in a door frame configuration. There are two reaction blocks  50 ,  52  attached to the outer cylindrical members  22 ,  24 . Both of these reaction blocks  50 ,  52  have threaded-through bores for threaded engagement with threaded rods or jackscrews  54 ,  56 . The jackscrews  54 ,  56  engage through the reaction blocks  50 ,  52  and connect to the end blocks  34 ,  36 . The jackscrews  54 ,  56  having knobs or handles  55 ,  57  are bidirectionally turnable such that the end blocks  34 ,  36  will move inwardly or outwardly with respect to the outer cylindrical members  22 , 24  depending on the direction of rotation of the knobs  55 ,  57 . A bolt assembly  33  connects each end block  34 , 36  to jackscrews  54 , 56  so that the end blocks  34 , 36  can be pushed outward or pulled inward depending on the direction of rotation of the jackscrews  54 , 56 . The bolt assembly  33  includes two locking nuts on the inside of each end block  34 , 36  and a screw and washer combination on the outside of each end block  34 , 36  threadably engaged with each jackscrew  54 ,  56 . 
   Referring now to  FIG. 2 , the jackscrew mechanisms are shown in a close up view. The end blocks  34 ,  36  are shown in retracted positions at  34   a  and  36   a  and in extended positions at  34   b  and  36   b . The inner cylindrical members  26 ,  28 ,  30 ,  32  can slide out of the outer cylindrical members  22 ,  24  until the inner cylindrical members  26 ,  28 ,  30 ,  32  are stopped by either door frame or by the handle engaging with the reaction blocks  50 , 52 . Assembly  33  is used in combination with the handles  55 , 57  of the jackscrews  54 , 56  to operate as an end stop for preventing the inner members  26 ,  28 ,  30 ,  32  from sliding completely out of outer members  22 ,  24 . 
   Now referring to  FIG. 3 , a modular adjustable hoist  10  is depicted positioned in a door frame configuration. The hoist  10  is placed into the door frame  60  such that an object  62  can be lifted up a flight of stairs  64 . The end blocks  34 ,  36  are extended by turning the knobs  55  and  57  in a direction that forces the jackscrews  54 ,  56  to extend outwardly from the outer cylindrical members  22 ,  24 . Leg extensions  46  and  48  can be inserted prior to or after the adjustable hoist  10  is wedged in-between the door frame sides  60 . Once the end blocks  34 ,  36  are engaged with the door frame  60  and the vertical extension members  46 ,  48  are in contact with the floor, then object  62  can be hoisted up the stairs  64 . 
   Now referring to  FIG. 4 , a second aspect of the adjustable hoist  10  can be used in a doorway configuration. The modular adjustable hoist  10  is in basically the same configuration as the door frame configuration except that two horizontal extension members  75  and  79  are attached to pins  73  and  77  on the end blocks  34 ,  36  such that the horizontal extension members  75  and  79  can be placed against the wall adjacent to the door frame for support of the adjustable hoist  10 . An object  62  can be lifted up the stairs  64  in the same manner as the door frame configuration without requiring the modular adjustable hoist  10  to be wedged into a door frame. Additionally, a support leg  72  is attached to a vertical extension member  48  in the doorway configuration. 
   Now referring to  FIG. 5 , a third aspect of the modular adjustable hoist  10  can be configured for use in a vehicle such as a cargo van. The adjustable hoist  10  has the same elements as shown in  FIG. 1 , with the addition of two support legs  70 ,  72  and two pads  74 ,  76  on top of the hoist  10 . The first support leg  70  is attached to vertical extension  46  and the second support leg  72  is attached to the vertical extension  48  to counteract lateral forces applied to the adjustable hoist  10  as an object is being moved. Additionally, two bolts  81 ,  83  having pads  74 ,  76  on the ends thereof are threadably engaged into the end blocks  34 ,  36  such that the bolts  81 ,  83  can be retracted or extended by turning each bolt  81 ,  83  in the correct direction. The pads  74 ,  76  engage the roof of the automotive vehicle to provide stiffness and support to the adjustable hoist  10  when lifting an object.  FIG. 6  shows the adjustable hoist  10  pulling a load  62  into the back of a van  78 . 
     FIG. 7  shows a fourth aspect of the invention as the adjustable hoist  10  is mounted in a free standing configuration. The modular adjustable frame  10  is rotated 90 degrees from the doorframe configuration shown in  FIG. 1  such that the winch  12  is facing downward. The end blocks  34 ,  36  each have two pins  88 ,  90  and  92 ,  94 , respectively, located at oblique angles from each other relative to the end blocks  34  and  36 . The pins  88 ,  90 ,  92  and  94  protrude outwardly for mounting the adjustable hoist  10  onto the support members  80 ,  82 ,  84  and  86 .