Heating apparatus for false twist yarn crimping machine

A yarn heating apparatus for use in a false twist yarn crimping machine or the like and comprising

• a heat insulating housing having a front face and an elongate channel in said front face, said channel having a generally U-shaped cross-sectional configuration which defines a bottom wall and opposite, generally parallel side walls,
• an elongate heater plate having a uniform arcuate curvature along its length and at least one longitudinally extending yarn receiving groove in the convex face thereof, said heater plate being disposed along said bottom wall in said channel so as to be in spaced relation from said front face of said housing and with said convex face and said yarn receiving groove facing outwardly from said channel,
• heating means operatively connected to said heater plate for elevating the temperature thereof,
• an elongate cover comprising a supporting plate and an insert mounted to one side of said supporting plate, said insert having a length conforming to the length of said channel and having a generally rectangular cross-sectional configuration which defines an inner face and parallel side edges which are spaced apart a distance which closely approaches the distance between said side walls of said channel, said insert further having an inner face which is arcuately curved along its length in conformance with the curvature of the convex face of said heater plate and a width sufficient to span each yarn receiving groove,
• means mounting said cover to said housing for movement between a closed position wherein said plate is disposed adjacent said housing front face with said insert disposed within said channel and with said inner face of said insert being disposed uniformly with respect to said convex face of said heater plate to define a yarn passage of substantially uniform cross-sectional configuration along the length of said heater plate, and an open position spaced from said housing, said mounting means including hinge means for sequentially guiding said cover for movement within a plane parallel to said side walls of said channel to withdraw said insert from said channel and then for pivotal movement about an axis extending generally parallel to the longitudinal direction of said channel when said cover is moved from said closed to said open position, and for reversely pivoting and linearly guiding said cover when the same is moved from said open to said closed position.