1294170 Tentering-apparatus PROCTOR & SCHWARTZ Inc 21 Aug 1970 [10 Oct 1969] 40370/70 Heading D1S [Also in Division B8] Conveying apparatus includes a race, non- linear at least in part, containing a plurality of balls whose number is less than the maximum number receivable in the race. In Fig. 2, an endless chain 15 has grooves 18 and is supported by balls 20 running in track members 12. Fig. 6 shows chain links of which tongues 22 are received within grooves 23 of adjacent links. Recesses (25) in the links receive a drive sprocket, Fig. 4 (not shown). Pivoted joints between sections of the track in Fig. 7 include tongue and groove portions 30, 31, the tongues being tapered and grooved at 32, 33 to aid guiding of the balls 20 when adjacent track sections are at an angle to each other. Although steel is specified as constructional material, plastics or glass fibres may be used. When using the conveyer in a tentering process, clamps or pin plates for holding the material being conveyed are secured to the chain links and a similar layout to that shown in Fig. 1 is provided at a distance corresponding to the width of the material being processed. Sensing means may further adjust this distance. For increasing or reducing the number of balls, there may be releasable cutaways in the track members 8, 10, 12. Part of the track section may have a removable cover. In place of the endless chain there may be a number of independent elements which may be pushed around the track. Alternatively the endless member may be a cable or belt. The member may be terminated instead of endless and be pulled or pushed.