Apparatus for laterally stretching textile fabric and the like

A device for laterally stretching a web of textile fabric or the like flexible material, comprising a pair of web-stretching devices engaging opposite side portions of said web, each of said pair of web-stretching devices including a first, a second and a third uncurling finger having a helical groove formed on the outer circumferential surface thereof;

• means for supporting said fingers in parallel with each other and rotatably about their respective axes;
• means for positively rotating at least one of said fingers;
• means for mechanically connecting said fingers for simultaneous rotation;
• a control roller rotatable about its own axis;
• means for supporting said control roller generally between said second and third fingers and in parallel therewith;
• said fingers and roller being so arranged as to engage a selvage of said web being longitudinally fed so that a lateral pulling force is exercised on said web selvage;
• means for detecting lateral displacement of said web relative to the feeding direction thereof;
• first position changing means operable in response to said displacement detecting means to change the position of said control roller relative to said fingers by displacing the axis of rotation of said control roller about the axis of rotation of said second finger, while keeping the parallel relation between said axes of rotation, thereby changing the magnitude of said lateral pulling force;
• second position changing means for changing the position of said displacement detecting means;
• and means for synchronizing the operations of said two position changing means said synchronizing means including an actuator mechanism for displacing said means for detecting lateral displacement of said web simultaneously with the position change of said roller.

A device for laterally stretching a web of textile fabric or the like flexible material, comprising a pair of web-stretching devices engaging opposite side portions of said web, each of said pair of web-stretching devices including at least a pair of parallel uncurling fingers rotatable about their respective axes;

• a control roller rotatable about its own axis and arranged in parallel with and generally between said fingers;
• said fingers and roller being adapted to engage a side portion of said web being longitudinally fed so that a lateral pulling force is exercised on said web side portion;
• means for detecting lateral displacement of said web relative to the feeding direction thereof and first position changing means operable in response to said detecting means for changing the position of said roller relative to said fingers by displacing the axis of rotation of said roller about the axis of rotation of one of said fingers, while substantially keeping the parallel relation of said axes of rotation, thereby changing the magnitude of said lateral pulling force exercised on said web side portion;
• means to change the distance between said pair of webstretching devices and second position changing means for changing the position of said detecting means in accordance with lateral displacement of said web.

A device for laterally stretching a web of textile fabric or the like flexible material, comprising a pair of web-stretching devices engaging opposite side portions of said web, each of said pair of web-stretching devices including a first, a second and a third uncurling finger having a helical groove formed on the outer circumferential surface thereof;

• means for supporting said fingers in parallel with each other and rotatably about their respective axes;
• means for positively rotating at least one of said fingers;
• means for mechanically connecting said fingers for simultaneous rotation;
• a control roller rotatable about its own axis;
• means for supporting said control roller generally between said second and third fingers and in parallel therewith;
• said fingers and roller being so arranged as to engage a selvage of said web longitudinally fed so that a lateral pulling force is exercised on said web selvage;
• means for detecting lateral displacement of said web relative to the feeding direction thereof;
• first position changing means operable in response to said displacement detecting means to change the position of said control roller relative to said fingers by displacing the axis of rotation of said control roller about the axis of rotation of said second finger, while keeping the parallel relation between said axes of rotation, thereby changing the magnitude of said lateral pulling force;
• means for supporting said pair of web-stretching devices in a laterally spaced apart relation to each other so that said web has each of its selvages engaged by said uncurling fingers and control roller of one of said pair of web-stretching devices;
• and translation means operable in response to said displacement detecting means to change the distance between said pair of web-stretching devices when web width changes and second position changing means for changing the position of said detecting means in accordance with lateral displacement of said web.