distal located rotary bodies 40 and 52 of the rectilinear array 38 the application of a rotary force at any point in the drive train results in simultaneous rotaton of each of the drive shafts 106 114 and each of the rotary bodies 40 50 of the rectilinear array 38 in order to facilitate mounting and demounting of the components of the rectilinear array the drive shafts 106 114 are demountably coupled to the drive shafts of the rotary bodies coupling is provided in a preferred arrangement through the use of coupling sleeves 116 one of which is illustrated in detail in fig5 in this figure the coupling shaft 106 is illustrated coupled to a rotary shaft 118 of the rotary body 42 by the coupling sleeve 116 the shaft 118 is preferably cylindrically shaped and engages the associated support roller bearing fig4 while the coupling sleeve 116 and the shaft 106 are tubular and are of rectangular cross sectional configuration alternatively sleeve 116 and shaft 106 can be configured with combinations of circular and rectangular cross sections as illustrated in fig5 the shaft 118 is cylindrical the drive shaft 106 is tubular and rectangular in cross section and the coupling sleeve 116 is similarly tubular and rectangular in cross section alternative combinations provide for a sleeve of rectangular cross section 116 with a tubular drive shaft 106 of circular cross section and a tubular sleeve 116 of circular cross section with a tubular drive shaft 106 of circular.