Pneumatically actuated redirect surface

Abstract

The present invention is directed to a pneumatically actuated redirection surface guide tool for use in tape laying systems. In the laying of unidirectional, pre-impregnated carbon fiber tapes, for instance, a tape can be directed between a tape supply reel and a tape laying head through use of one or more of the disclosed guide tools. The surface of the guide tool includes small holes that allow for positive and negative air pressure to be applied to the surface to increase or decrease the friction between the tape that is passing over and being redirected by the surface.

What is claimed is: 
     
         1 . A pneumatically actuated redirect surface for use in steering and directing a tape web, the surface comprising:
 a guide tool comprising a curved substantially smooth surface, wherein the surface has perforations therein, and wherein the surface comprises a tangent contact portion;   the guide tool further comprising a manifold therein, with the perforations in the surface in fluid communication with the manifold; and   a moveable tool mount, wherein the mount carries the guide tool and is adapted to be movable,   whereby the tool is movable and the entry and exit points of a tape web moving over the surface is able to be changed while a tape is in motion.   
     
     
         2 . A pneumatically actuated redirect surface as described in  claim 1 , wherein the tangent contact portion of the tool surface is a straight line. 
     
     
         3 . A pneumatically actuated redirect surface as described in  claim 1 , wherein the tangent contact portion of the tool surface is not a straight line. 
     
     
         4 . A pneumatically actuated redirect surface as described in  claim 1 , wherein the tool surface is comprised of a flexible sheet which has the perforations therein, and wherein the tangent contact portion of the tool surface is not a straight line. 
     
     
         5 . A pneumatically actuated redirect surface as described in  claim 1 , wherein the tool mount is movable in a rotatable manner about an axis of rotation, and wherein the axis of rotation is substantially the center of the tangent contact portion of the surface. 
     
     
         6 . A pneumatically actuated redirect surface as described in  claim 1 , wherein the tool surface is curved in the shape of a part of a circle. 
     
     
         7 . A pneumatically actuated redirect surface as described in  claim 6 , wherein the tool surface is curved in the shaped of a semi-circle. 
     
     
         8 . A method of steering and directing a tape web in its path of travel from a supply roll to a work surface comprising the steps of:
 providing a guide tool comprising a curved, substantially smooth surface, wherein the surface has perforations therein, and wherein the surface comprises a tangent contact portion; the guide tool further comprising a manifold therein, with the perforations in the surface in fluid communication with the manifold; providing an air pressure pump in fluid communication with the manifold, wherein the pump is adapted to provide positive air pressure to the manifold;   providing a tape web;   moving the tape web, and positioning the moving web over the surface of the guide tool;   wherein the direction of travel of the moving web changes between an approach path toward the guide tool surface and a departure path from the guide tool surface; and   activating the pump to deliver positive air pressure to the manifold,   whereby air provided into the manifold and forced out of the perforations provides a lifting pressure between the guide tool surface and the tape web that reduces the friction otherwise caused by movement of the web over the surface.   
     
     
         9 . A method as described in  claim 8 , wherein the pump is also adapted to provide vacuum air pressure to the manifold. 
     
     
         10 . A method as described in  claim 8 , wherein the guide tool is rotatable about an axis of rotation,
 and the method further comprising the step of moving the guide tool simultaneously with moving the tape web across the surface of the guide tool;   wherein the tape web has a substantially zero Gaussian curvature as it moves across the guide tool surface.   
     
     
         11 . A method as described in  claim 8 , wherein the tangent contact portion of the tool surface is a straight line. 
     
     
         12 . A method as described in  claim 8 , wherein the tangent contact portion of the tool surface is not a straight line. 
     
     
         13 . A method as described in  claim 8 , wherein the tool surface is comprised of a flexible sheet which has the perforations therein, and wherein the tangent contact portion of the tool surface is not a straight line. 
     
     
         14 . A method as described in  claim 8 , wherein the tool surface is curved in the shape of a part of a circle. 
     
     
         15 . A method as described in  claim 8 , wherein the tool surface is curved in the shaped of a semi-circle. 
     
     
         16 . A method as described in  claim 8 , wherein the tape web comprises a laminate of a pre-impregnated fiber tape on a backer web. 
     
     
         17 . A method as described in  claim 16 , wherein the fiber tape is a carbon fiber tape and the backer web is silicone coated paper.