Patent ID: 8312601

Claim:
A strap-tightening device comprising: a frame ( 10 ) including two walls ( 12 ) each including a first edge ( 19 ), a second edge ( 16 ) and a stop ( 17 ) formed between the first and second edges ( 19 ; 16 ); a first spring-biased detent ( 50 ) located on the frame ( 10 ); a handle ( 20 ) formed with two cams ( 22 ) and pivotally connected to the frame ( 10 ); a second spring-biased detent ( 60 ) located on the handle ( 20 ), the second spring-biased detent ( 60 ) including a tail ( 63 ) and two horns ( 62 ) extending opposite to the tail ( 63 ) and each including a downward prong ( 65 ) and an upward prong ( 66 ); a reel ( 30 ) rotationally located on the frame ( 10 ), the reel ( 30 ) including a cylinder ( 31 ) and two ratcheted wheels ( 32 ) attached to the cylinder ( 31 ) and each formed with ratchets, wherein the ratcheted wheels ( 32 ) are engaged with the upward prongs ( 66 ) of the horns ( 62 ) of the second spring-biased detent ( 60 ) during pivoting of the handle ( 20 ) in a direction to cause the cylinder ( 31 ) to reel in a strap ( 72 ), wherein the ratcheted wheels ( 32 ) are engaged with the first spring-biased detent ( 50 ) during pivoting of the handle ( 20 ) in an opposite direction to prevent the handle ( 20 ) from spinning the cylinder ( 31 ) to reel out the strap ( 72 ); and a withdrawing unit ( 40 ) including an end connected to the reel ( 30 ) and another end connected to the frame ( 10 ) for causing the reel ( 30 ) to withdraw the strap ( 72 ); wherein the tail ( 63 ) can be pressed to lift the downward prongs ( 65 ) above the stops ( 17 ) to allow pivoting of the handle ( 20 ) between first and second modes; wherein in the first mode, the handle ( 20 ) stays near the frame ( 10 ) so that the cams ( 22 ) disengage the first spring-biased detent ( 50 ) from the ratcheted wheels ( 32 ), and that the downward prongs ( 65 ) engage with the stops ( 17 ) to avoid pivoting of the handle ( 20 ) from the frame ( 10 ), and that the downward prongs ( 65 ) rest on the first edges ( 19 ) while a lower side of each of the upward prongs ( 66 ) contacts an inclined edge of any of the ratchets ( 33 ) of a related one of the ratcheted wheels ( 32 ) to allow the second spring-biased detent ( 60 ) to exert a torque on the reel ( 30 ) to encounter an opposite torque exerted by the withdrawing unit ( 40 ) to avoid withdrawing of the strap ( 72 ) but allow unwinding of the strap ( 72 ); wherein in the second mode, the downward prongs ( 65 ) stay near the second edges ( 16 ) while each of the upward prongs ( 66 ) abuts a vertical edge of any of the ratchets ( 33 ) of a related one of the ratcheted wheels ( 32 ) so that the handle ( 20 ) can be pivoted to spin the reel ( 30 ) to reel in the strap ( 72 ), and that the tail ( 63 ) can be pressed to lift the upward prongs ( 66 ) from the ratchets ( 33 ) to allow the withdrawing unit ( 40 ) to spin the reel ( 30 ) to withdraw the strap ( 72 ).