Worm drive clamp with band guide channels

Claim 1

A worm drive clamp comprising a flexible metal clamping band having a housing secured to a securing end thereof, said band having a plurality of spaced apart engageable openings in at least a free end portion thereof, said housing having a screw retention portion and a lower band receiving portion, said band receiving portion having opposed guide channels through which opposed edge portions of said free end portion of said band is caused to pass to position said free end portion for engagement and disengagement with a displaceable axially rotatable tightening screw located thereabove in said screw retention portion; said screw having a screw thread portion, a pivoting end portion, an engageable head at an opposed end to said pivoting end portion, and an annular groove intermediate said engageable head and said thread portion; said screw retention portion of said housing having an end wall with a retention opening for receiving said screw pivoting end portion captive therein but providing longitudinal axial displacement and pivotal displacement thereof, said screw retention portion of said housing having an opposed end wall with a head receiving slot; said head receiving slot having a first portion with opposed arcuate side walls disposed about a center point which lies on a central axis of said retention opening, said first portion accommodating the passage of said head therein, and a second portion which is a U-shape slot disposed above said head receiving slot for receiving said annular groove closely spaced therein but preventing the passage of said head when said screw is displaced outwardly to a disengaged angular position; said opposed arcuate side walls providing a frictional abutment for said head to retain said screw thread portion in an engageable position with said spaced apart openings in said band free end portion, said band free end portion remaining substantially in a fixed arcuate plane by said opposed guide channels during engagement and disengagement thereof from said housing, said guide channels being formed integrally with said housing and extending outwardly from opposed side walls of said screw retention portion of said housing to define wing portions, said guide channels further being of rectangular cross-section and arcuately extending and further having a top and bottom arcuate wall and an outer interconnecting side wall, an arcuate tab is punched in said arcuate top wall to define a restricted throat section in said arcuate channels at mid-length thereof to maintain said band free portion in said fixed arcuate plane spaced from said tightening screw a predetermined distance.