Tightening device with easy alignment for securing a ceiling fan to a fitting

A tightening device with easy alignment adapted for securing a ceiling fan to a fitting which is used to mount the ceiling fan onto a flat ceiling wall, the ceiling fan including a motor casing with an upper major wall, a rotor shaft disposed in and rotatable relative to the motor casing about a first axis, and an upright coupling member disposed in the motor casing and extending outwardly of the upper major wall of the motor casing along the first axis,

• the fitting including
• (a) a mounting bracket which has an abutment wall to be fixed on and to abut against the ceiling wall, and a pair of retaining halves suspended from the abutment wall, and spaced apart from each other in a radial direction relative to the first axis to define a retaining bore for receiving the upright coupling member, and
• (b) a protective covering member which has an upper annular secured portion surrounding and fixedly secured to the abutment wall of the mounting bracket so as to shield the abutment wall radially, and a skirt portion circumferentially extending from the annular secured portion about a second axis and downwardly to form a lower annular wall,
• said tightening device comprising:
• (a) an annular flange member adapted to extend inwardly and radially from the lower annular wall of the protective covering member to define an opening with a first dimension which is adapted for passage of the upright coupling member;
• (b) an anchored flat sheet adapted to be formed with the upper major wall of the motor casing, and having upper and lower anchored walls opposite to each other in an axial direction parallel to the first axis, said anchored flat sheet further having an inner peripheral wall which extends from said upper anchored wall in the axial direction to communicate with said lower anchored wall to define a central hole that is adapted for passage of the upright coupling member, said upper anchored wall defining a plurality of first fastening positions which are proximate to said inner peripheral wall and which are angularly spaced apart from one another;
• (c) an upper annular clamping member having an outer circumferential portion surrounding a third axis, and an inner circumferential portion which extends inwardly and radially from said outer circumferential portion to define an inserting hole that is adapted for insertion of the upright coupling member to bring the third axis to coincide with the first axis, said upper annular clamping member being of a dimension such that when said upper annular clamping member is placed on said annular flange member to bring the second axis to coincide with the third axis, said outer circumferential portion will couple sandwich said annular flange member thereto, said inner circumferential portion of said upper annular clamping member defining second fastening positions which corresponds to said first fastening positions in terms of number and relative position;
• and
• (d) a plurality of fastening members, each disposed to fasten said anchored flat sheet and said inner circumferential portion of said upper annular clamping member together along said first and second fastening positions when said annular flange member is sandwiched between said outer circumferential portion, and when each of said first fastening positions is aligned with two corresponding ones of said second fastening positions in the axial direction.