Shot processing apparatus

A shot processing apparatus comprising:

• a generally cylindrical drum shaped to have an open one end and a closed other end;
• a centrifugal projector arranged rotatable by a rotary shaft to throw a blasting material out therefrom into the open one end of the generally cylindrical drum;
• a blade wheel provided in the centrifugal projector and having a plurality of blades rotatable in a first rotational direction around a rotational axis, the plurality of blades being configured to receive the blasting material and throw the received blasting material out of the centrifugal projector by operation of centrifugal force generated by its rotation in the first rotational direction around the rotational axis,
• wherein each blade comprises a front surface facing in the first rotational direction and a rear surface facing in a second rotational direction opposite to the first rotational direction, the front surface being bifurcated into radially contiguous first surface and second surface arranged, respectively, on radially inner and outer sides of the front surface, the first and second surfaces both being inclined in the second rotational direction at first and second angles, respectively, with respect to a radius of the blade wheel, the second angle being smaller than the first angle with respect to the radius of the blade wheel, and
• wherein each blade is formed with a pair of planar side walls having front edges and rear edges and extending perpendicularly to the rotational axis through a radial length of the blade along circumferential sides of the front surface, the front edges being shaped straight throughout its radial length and projecting generally in the first rotational direction from the circumferential sides of the front surface, the rear edges being shaped straight in parallel to the front edges except radially inner end portions thereof from which locking portions project in the second rotational direction;
• and
• a pair of circular side plates provided in the centrifugal projector in parallel to each other along the rotational axis and arranged to secure the plurality of blades between them, the pair of circular side plates being formed in their opposing surfaces with guide channels at equal angular intervals, the guide channels extending radially outward and being inclined in the second rotational direction at a third angle from the radius of the circular side plates, the guide channels being shaped to securely receive the plate side walls of the blades
• wherein at least one of the guide channels of each circular side plate is provided with a recessed portion formed in the guide channel and with an insertion hole formed in a bottom of the recessed portion, the insertion hole running through the circular side plate, and
• wherein the pair of circular side plates are attached to the rotary shaft by bolts inserted through the insertion hole with heads of the bolts being hidden within the recessed portions.