Method of making a preformed semirigid plastic hose wrapped with a wire spiral

Abstract

The invention provides a hose that withstands a vacuum which is considered to be approximately two to three times greater than the vacuum withstood by the best known previously available pliable convoluted semirigid plastic hoses of comparable designs. To fabricate the hose, a bobbin of wire stock is unwound, with the wire preferably being pulled off the end of the bobbin. The wire is then looped around a spool to form it into a spiral or coil having a preset diameter which is proportionately smaller than the diameter of a preformed, semirigid convoluted plastic hose. While the pulled wire is still substantially extended, it is taken up by being rolled upon the plastic hose, thereby snapping the preset formed wire spiral into the spiral convolutions formed in the surface of the hose. If desired, the spiral or coil might be pulled off the end of the smaller diameter spool to impart a twist thereto.

Dependencies are inferred from the claim text.