The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 29, 1976
Filed:
Apr. 28, 1975
William L Steward, Costa Mesa, CA (US);
Steward Plastics, Inc., Santa Ana, CA (US);
Abstract
An apparatus for making helically wound and helically ribbed plastic tubing, comprising: means for extruding a plastic strip having a longitudinal rib; winding means for helically winding the strip about an axis into a tube with one edge of each convolution overlapping and heat bonded to an edge of a preceding convolution and with the rib of the exterior of the tube, the winding means comprising four cantilevered rolls uniformly circumferentially spaced apart around and extending in the direction of the axis and canted relative to the axis at acute angles, opposite rolls being oppositely canted; and means for driving the rolls. The apparatus further includes means for applying a coolant to the tube externally and internally thereof to cool the plastic material after the convolutions of the tube have been heat bonded together. The apparatus further includes a roller engageable with the helical rib on the tube opposite one of the rolls to flatten the rib in zones where it is desired to sever the tube into shorter lengths and to provide such shorter lengths with smooth ends.