with reference to fig1 and 2 , a retractable tape measure in accordance with the present invention comprises a cover ( 10 ), a base ( 20 ) and a calibrated tape ( 30 ). the cover ( 10 ) has a top , four sides , four corners and four mounting posts ( 11 ). the top has four edges ( not numbered ) with a side extending down perpendicular from each edge , thereby forming an inside and an outside of the cover ( 10 ). a mounting post ( 11 ) is mounted inside the cover ( 10 ) near each corner . the base ( 20 ) has a bottom , four sides , four corners , four mounting bosses ( 21 ), two spring pins ( 23 ), two flat coil springs ( 25 ) and two spring belts ( 26 ). a tape slot ( 201 ) is defined through one side of the base ( 20 ). the bottom has four edges ( not numbered ) with a side extending up perpendicular from each edge , thereby forming an inside and an outside of the base ( 20 ) and four corners . the mounting bosses ( 21 ) are mounted inside the base ( 20 ) respectively near each corner corresponding to the mounting posts ( 11 ) inside the cover ( 10 ). a hole ( 22 ) is defined in each mounting boss ( 21 ), so the corresponding mounting post ( 11 ) can be inserted into the hole ( 22 ). the two spring pins ( 23 ) are mounted along a longitudinal centerline inside the base ( 20 ). a slot ( 24 ) is defined longitudinally in each pin ( 23 ). each flat coil spring ( 25 ) has an inner end ( not numbered ) and an outer end ( not numbered ). a central hook ( 251 ) is defined on the inner end of each coil spring ( 25 ). the central hook ( 251 ) of each flat coil spring ( 25 ) is mounted in the slot ( 24 ) to securely attach the flat coil spring ( 25 ) to the corresponding pin ( 23 ). a circumferential hook ( 252 ) is defined on the outer end of each coil spring ( 25 ). each spring belt ( 26 ) has an inside and an outside . transverse ribs are formed on the outside of each spring belt ( 26 ). a transverse slit ( 261 ) is defined on the inside of each spring belt ( 26 ). a spring belt ( 26 ) is mounted around each coil spring ( 25 ), and the circumferential hook ( 252 ) on the outer end of each coil spring ( 25 ) is securely mounted in the transverse slit ( 261 ) in the corresponding spring belt ( 26 ). the calibrated tape ( 30 ) has a proximal end ( not numbered ) and a distal end ( not numbered ) and is wrapped around an elliptical belt ( 33 ). a rigid lip ( 31 ) is attached perpendicular to the distal end of the calibrated tape ( 30 ). a belt hook ( 32 ) is formed on the proximal end of the calibrated tape ( 30 ). the elliptical belt ( 33 ) has an inside and an outside . the belt hook ( 32 ) is mounted in a transverse slit ( 34 ) defined on the outside of the elliptical belt ( 33 ). the inside of the elliptical belt ( 33 ) has a rough surface and is mounted around the outside of the two spring belts ( 26 ). the belt hook ( 32 ) on the proximal end of the calibrated tape ( 30 ) is inserted into the transverse slit ( 34 ), and the calibrated tape ( 30 ) is wound around the elliptical belt ( 33 ) with the rigid lip ( 31 ) on the distal end of the calibrated tape ( 30 ) through the tape slot ( 201 ). the retractable tape measure in accordance with the present invention is essentially the same size as a conventional tape measure . however , the elliptical belt ( 33 ) mounted around the two flat coil springs ( 25 ) has a circumference significantly larger than that of a single coil spring . consequently , a much longer calibrated tape ( 30 ) can be wound around the elliptical belt ( 33 ) so the retractable tape measure in accordance with the present invention can measure a much longer distance . the user pulls the calibrated tape ( 30 ) with the rigid lip ( 31 ) out from the base ( 20 ) when the user wants to measure with the retractable tape . the elliptical ring ( 33 ) will be actuated to rotate when the retractable tape ( 30 ) is pulled out from the base ( 20 ), and the two spring belts ( 26 ) will be actuated to rotated by the retractable tape ( 30 ) so as to tighten the coil springs ( 25 ). accordingly , the two coil springs ( 25 ) have a resilient force to pull the retractable tape ( 30 ) back to the base ( 20 ) automatically when the user releases the retractable tape ( 30 ). it is to be understood , however , that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description , together with details of the structure and function of the invention , the disclosure is illustrative only , and changes may be made in detail , especially in matters of shape , size , and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed .