where thewear is small or none at all, the plate, when worn on one side and therefore reversed, will still be firmly held in the ma chine so lthat it is able to produce an edicient crushing work. The front sides of the plates said bearing surfaces may also be lined with wear plates. ln order that the plates shall be capable of resisting the pres sure when supported at their edges only,raw Mill Flow Diagram For Cement Plant, the plates must be comparatively thich, and in order to decrease their weight it is suitable to provide the plates with channels extending through the plates intermediate their ribbed sides.

The accompanying drawing illustrates the invention by way of example. Fig. l shows a vertical section through a sto e crusher provided with crushing plates ac cording to the invention, and Fig. 2 shows a horizontal section of Ythe stone- Crusher. Fig. 3 shows a modified construction of a crushing plate in elevation, and Fig. 4l shows a cross section of the same.4 F 5 shows an elevation and Fig.Robo Sand Machinery 6 a cross section of a seating frame foi-the crushing plate shown in Figs. 3 and 4t, the left-hand halves of Figs. 5 and 6 showing the frame provided with interior longitudinal lists, and the rigl1t-hand halves showing the frame without such lists. Fig. l illustrates diagrammatically a further embodiment of the in vent-ion. y

Referring to Figs, l and 2, l denotes the frame of the stone Crusher in which the aw 2 is movable on its shaft 3. stationary crushing plate a’-, which has rectangulaa,l shape, in the usual manner, is supported in the machine frame .l by a seating 5. its illustrated in Figs. l and 2, said seating has rectangular shape and supports with its longitudinal or vertical parts the plate -l which for this purpose is provided with bearing surfaces 6 on both sides at its lonl gitudinal or vertical edges. The seating frame 5 is held in position in the machine frame l by shoulders ‘l projecting from its rear side into recesses El in the ifiiachine frame. rEhe crusl’iing plate l is held between the upper and lower sides or parte of the seating frame 5, as show i l. and is held bearing against the vertical sides of said seating frame by wedges inserted in the machine frame l. and the later l jecting flanges l0 of which bear aesinet ti; bearing surfaces onthe front side ol crushing plate 1l.