fig1 is taken from u . s . pat . no . 5 , 085 , 036 . there a mounting frame 10 is provided for the component parts for forming a flat sheet of film 14 into a tubular shape . the sheet of film 14 is unrolled from a roll 12 mounted on a spindle 13 . various rollers , e . g . roller 15 , tension the sheet of film 14 and align the sheet of film 14 for feeding the sheet of film 14 over a forming collar 16 . collar 16 forms the film 14 into a tubular shape with overlapping edges and directs the film 14 onto a generally cylindrical tube 18 . there the overlapping edges are sealed by some means such as by application of a heat seal , adhesive or the like . the depicted device uses a heated band 21 mounted on pulley wheels 23 , 25 to effect a seal . the film 14 is advanced on tube 18 by endless belts 27 , 29 positioned on opposite sides of tube 18 . referring to the remaining figures , there is depicted the improvement of the apparatus of the invention is supported on the mounting frame 10 upon which the components for forming the flat sheet of film 14 into a tubular shape are arranged . the film 14 is released from a roll 12 of flat film 14 . the sheet 14 of film passes over various rollers and guides and ultimately over the collar 16 which forms the flat film 14 into a tubular shape . the sheet of film 14 then folds over a generally cylindrical tube 18 where the overlapping longitudinal edges of the sheet of film 14 may be sealed by some means such as by application of adhesive , heat or the like . the tube 18 has a centerline 20 . positioned on opposite sides of the tube 18 generally equal distances from the center line 20 are first and second spaced transport assemblies 22 and 24 . each spaced transport assemblies 22 and 24 may be , for example , be a boggie mounted drive belt such as depicted in u . s . pat . no . 5 , 085 , 036 . other types of transport assemblies or drive units 22 , 24 may utilized and still be within the scope of the present invention . the first spaced transport assembly 22 is slidably mounted on transverse support bars 26 and 28 which extend transversely to the center line 20 and connect with the frame 10 . the second assembly 24 is likewise slidably mounted on the bars 26 , 28 . the assemblies 22 and 24 are thus , slidably mounted on the bars 26 and 28 by means of slide mounts 30 and 32 . the first assembly 22 is typically attached to a transfer arm 34 by a pivot connection 36 . the opposite end of the arm 34 is pivotally attached by a transfer pivot connection 38 to a plate 40 . the plate 40 is generally circular in configuration and is mounted on the frame 10 to pivot about a vertical axis 42 . a second arm 44 is pivotally connected to the second transfer assembly 24 through a pivot connection 46 . the opposite end of arm 44 is pivotally attached to plate 40 at pivot connection 48 . note that pivot connection 48 is opposite the connection 38 and on the opposite side of a line through the axis 42 and parallel to the bars 26 and 28 . a handle 50 is provided for manual rotation of the plate 40 . in dicia or detents 52 are provided to indicate the amount rotation of the plate 40 about axis 42 . the plate 40 may be rotated by motor means ( not shown ) as well as manually . in operation , each transport assembly 22 and 24 is moved toward and away from the centerline 20 uniformly and simultaneously by rotation of the plate 40 . rotation of the plate 40 in a first direction will cause the arm 44 to move toward the center line and will simultaneously cause the arm 34 to also be moved toward the center line . this simultaneously causes the assemblies or units 22 and 24 to slide on the transverse bars 26 and 28 simultaneously and uniformly . in the preferred embodiment , the arms 34 and 44 are attached to the plate 40 and arranged so that the pivot connections 38 and 48 are equal radial distances from the axis 42 . placement of the pivot connections 38 , 48 at unequal distances from the axis 42 would cause non uniform translation of the assemblies 22 and 24 upon rotation of the plate 40 . in certain circumstances this may be desirable . when the assemblies 22 and 24 are properly positioned relative to a cylindrical tube 18 and with respect to the centerline 20 of the tube 18 , the detents 52 should be noted . a locking arm 57 may be operated co - jointly with the plate 40 to insure that the plate 40 and thus the assemblies 22 and 24 are locked into a desired detent position . in this manner , the position of the assemblies 22 and 24 is reproducible with respect to the center line 20 of the cylindrical tube 18 . thus , the construction which is depicted can be utilized to uniformly and simultaneously move boggie mounted drive belts , for example , such as shown in u . s . pat . no . 5 , 085 , 036 . obviously , other types of drive assemblies may be utilized other than those shown in u . s . pat . no . 5 , 085 , 036 . thus , while there has been set forth a preferred embodiment of the invention it is to be understood that the invention is to be limited only by the following claims and their equivalents .