Centrifugal projecting machine

A centrifugal projecting apparatus for projecting members, said apparatus comprising an impeller having radially located impeller blades and spaced first and second side impeller plates to which the blades are fixed, an impeller cover that surrounds front, rear, left, right, and ceiling sides of the impeller, said impeller cover having first and second side cover components having openings at left and right sides of said impeller, plate-like front and rear side cover components at front and rear sides of said impeller, and a moveable ceiling side cover component at an upper side of said impeller, said impeller cover being generally shaped like a box formed as a trapezoid, first and second side liner components located inside of and to protect the left and right sides of the impeller cover, front and rear side liner components located inside of and to protect the front and rear sides of the impeller cover, a ceiling-side liner component located inside of and to protect the ceiling side of the impeller cover, and a frame liner component for holding the first and second side liner components, front and rear linear components and ceiling side liner component together, wherein

• said first and second side liner components are generally shaped like trapezoids and have openings at the center thereof through which the first and second side impeller plates can pass, said first and second side liner components being fixed to the impeller cover by screws,
• said front and rear side liner components are generally U-shaped and inclined and are pressed against and fixed on right and left ends of the first and second side liner components by bolts that pass through the front- and rear-side cover components of the impeller cover,
• a labyrinthine structure is formed at the connecting surfaces between the ceiling side liner component and the first- and second-side liner components, said labyrinthine structure having at least four bent points bent in the direction of the projection of the projecting members to prevent the members from passing through said connecting surfaces,
• said frame liner component is shaped as a loop having a vertical plate that defines an opening through which upper ends of the first and second and front and rear liner components pass and are engaged with, pressed against, and fixed on the impeller cover, and
• said ceiling side liner component has a looped-projection 38 formed along the periphery of a lower surface thereof, said looped-projection being inserted into U-shaped grooves defined in the upper ends of the first and second and front and rear liner components and into the vertical plate of the frame-liner component, said ceiling-side liner component being pressed and held in place by a fixing member located on the impeller cover so that it is fixed on the frame-liner component.