roller segments 33 34 are attached to and rotatable with axle 27 as in the previously described embodiment also sprocket wheel 36 disposed between roller segments 33 34 is attached to and rotatable with axle 27 with chain drive 38 being connected about sprocket wheel 36 and drive wheel 39 driven by electric motor 40 axle 31 in this embodiment also supports a pair of spaced roller segments as designated by reference numerals 83 84 brackets 23 24 have aligned openings that house bearings 85 86 for rotatably receiving the ends of axle 31 an additional sprocket wheel 89 is secured to axle 31 and provided with a drive chain 90 therearound drive chain 90 is also disposed about a drive wheel 91 driven by electric motor 40 through the same drive shaft 41 that drives wheel 39 drive wheels 39 91 are of the same diameter and thus rotate at the same speed as driven by drive shaft 41 also sprocket wheels 36 89 are of equal diameter to insure equal speed rotation of axles 27 31 the use of the double drive embodiment illustrated in fig9 is not normally needed for short stairways up to six steps but does prove practical for stair lifts employed on longer stairways the operation of the invention is now believed apparent from the above description the stair lift assembly is considered portable in that it can be installed or removed by two workmen without altering an existing stairway in the illustrated preferred embodiment the stair lift is installed on a four step stairway and the elongated metal members 11 12 constructed of.