their centers as will be described in more detail at a later stage in the text all the components described in conjunction with fig1 are connected to one another in an easily releasable manner and be exchanged in modular fashion it is thus possible for example for the transverse frame elements to be exchanged for other transverse frame elements of a different width if a greater conveyor width is desired the hollow aluminum profiles 4 and 5 can be exchanged for ones which have different distances between the centers of the load bearing rollers or are rotated in the manner according to the invention in order to bear load bearing belts with sliding action the last described possibility can best be seen in fig2 the latter illustrates a cross section through a hollow aluminum profile 4 5 of the invention it can be seen that the profile is of essentially h shaped design the top legs 8 which form the large h being connected to one another in their end regions by a transverse partition 9 on which the load bearing belt which is indicated at 10 is supported with the interposition of a sliding plate 11 the legs 13 which extend on the other side of the crosspiece 12 of the h shaped hollow aluminum profile are not closed in the outward direction the load bearing rollers being inserted between them as will be explained at a later stage in the text for this purpose the hollow aluminum profile is rotated through 180 u00b0 as is illustrated in fig3 the same parts are provided with the same designations therein fig2 and 3 designates bores which extend along the hollow aluminum profile and in which it is possible to introduce fastening or centering elements for joining together adjacent conveyors.