264,450. Dwight & Lloyd Metallurgical Co., (Assignees of Knox, J.). Jan. 15, 1926, [Convention date]. Open-pan sintering-apparatus. - An ore treating or sintering machine comprising an endless chain of ore receptacles passing over upper and lower tracks is provided at the driving and charging end with curved tracks connecting the upper and lower tracks spaced from sprocket wheel propelling means so that the receptacles will adjust themselves to the drive without tilting against one another. Improvements in the sprocket drive and in supports for the wind-box and dead-plate are also described. A chain of ore receptacles 4, Fig. 1, are driven by a sprocket wheel 7 along upper tracks 2 and lower tracks 3, back to the sprocket wheel, and then by a curved track 12 with concentrically disposed webs 12a, 12b, Fig. 2, between which wheels 6 on the receptacle 4 travel. The tracks 12 are located on a curve distant from and eccentric to the axis of sprockets 7, whereby the wheels 6 of the ore receptacles are kept out of contact with the driving sprockets. When the empty receptacles are delivered on the upper track, and sprockets 7 engage projections 6<a>, Fig. 7, on the receptacles, the latter are pulled free from each other and assume by gravity their proper positions. The sprockets 7 have an uneven number of teeth and the receptacles an even number, which prevents the same teeth re-engaging and reduces wear. The sprocket wheels 7 have replaceable toothed rings 7<b>, Fig. 7, secured by rivets, and may be rotated in any desired way as by gears 16 detachably secured by rivets. The gears 16, Fig. 5, are in mesh with pinions 17 secured on a shaft 18. In order to adjust the sprocket wheels 7 with regard to the length of the tracks 2, bearings 9 and 18<a>, Fig. 5<a>, are secured on bars 19 slidably supported on longitudinal saddles 19<a> secured on spaced beams 1<b>, Fig. 7. The bars 19, Fig. 5<a>, are adjusted longitudinally by screws 20 and retained in position by set screws. The shaft 18, Fig. 5, may be driven by gears 24 meshing with pinions 25 on a shaft 26 carried in bearings 27 longitudinally adjustable as are bearings 9, 18<a>. To avoid torsion on the shaft 26, a centrallv disposed gear 28 is provided in mesh with a drive pinion (not shown) on a shaft 30. This shaft may be driven by reducing gearing 31 - - 35, driven by a pulley 36. At the discharge end of the machine tracks 12<c>, Fig. 1, preferably of the same construction as the racks 12, are employed. Sprocket wheels 37 are spaced from the tracks 12<c>, and are secured on a shaft 38 in bearing boxes 39, slidably supported in guides 40. The boxes are connected with rods 42<1> pivoted at 43 to levers 44, themselves pivoted at 45 to the main frame. The free ends of the levers are connected to chains passing over pulleys 47 to weights 48, whereby the shaft 38 and sprockets are drawn towards the charging end of the machine, but when the receptacles are exposed by heat the sprockets 37 are pushed forwards against the .action of the weights 48. Wind-boxes 14 may be supported on the main frame below the tracks 2 in any desired or known way. An outlet 15 is connected with an exhaust. One or more wind-boxes may be used. A series of wind-box sections 14<a> may be riveted together and slidably supported by ledges 14b resting on longitudinal bars 1<a> extending above the main frame. A shell 14<c> is riveted at 1<b> to the sections 14a which have a closed end. Flexible sealing strips c resist inflow of air into the windbox. The forward dead-plate 10<a>, Fig. 5, is secured to the adjacent forward wind-box section 14a which dead-plate rests slidably on the bars 1<a>. The rear dead-plate 10 is secured to the main frame. Hence wind-boxes and the forward dead-plate move freely backward and forward without transmitting strains due to heat.