Patent ID: 7185553

Claim:
A screw feed apparatus comprising: a screw shaft having a screw groove formed in the outside diameter surface thereof; a nut having a screw groove formed in the inside diameter surface thereof opposed to said outside diameter surface of said screw shaft; a number of rolling bodies rollably interposed between said two screw grooves of said screw shaft and nut; a circulation passage that is disposed on an exterior of said nut, returns said rolling bodies to the nut and has flection portions at both ends thereof; and, deflector pieces formed separate from the circulation passage and disposed in said nut for connecting said circulation passage to a rolling passage formed between said two screw grooves, wherein each of said deflector pieces comprises a plurality of divisional pieces and, in said divisional pieces, there are respectively formed rolling body guide grooves cooperating together in forming a rolling body guide passage for guiding said rolling bodies to said circulation passage, and a projection portion and a hole portion are formed on each of the divisional pieces of each of the deflector pieces so that the projection portion of one of the divisional pieces fits in the hole portion of an adjacent one of the divisional pieces to thereby integrate the divisional pieces of respective deflector pieces.