Patent ID: 7748756

Claim:
A combination of a part and a housing box which accommodates the part, wherein: the part includes a cantilevered first lock unit provided on a first sidewall of the part, the first lock unit including: a supporting unit having a curved surface, the curved surface including two outer portions that are connected to the first sidewall, and a middle portion that is positioned between the two outer portions and separated from the first sidewall by a slit; a lock arm having a band plate shape, extending upward from the supporting unit, and being deflectable toward the first sidewall; and a first engagement protrusion positioned on the lock arm, and extending away from the first sidewall; and the housing box includes a second lock unit that is engageable with the first lock unit, the second lock unit including: a second sidewall of the housing box; a third sidewall of the housing box that is substantially parallel to the second sidewall; a second engagement protrusion positioned on the third sidewall, and engageable with the first engagement protrusion; a mold hole positioned between the second and third sidewalls; and an abutment surface positioned at an upper end of the second sidewalk, and configured to prevent communication between the mold hole and the slit by, when the second engagement protrusion engages the first engagement protrusion, contacting the curved surface of the supporting unit.