Apparatus for guiding a curved strip

Apparatus for guiding an elongate strip of a stiff material which is prestressed to be cambered in a transverse direction, so that it has a wide transversely concave and a wide transversely convex surface and two narrow side surfaces, said apparatus comprising:

• at least one contact surface which to each portion of the strip bearing against it by one of said wide surfaces imposes a longitudinal curvature about a transverse axis, thereby reducing resiliently the transverse camber of said portion of the strip,
• and first and second lateral support surfaces disposed in mutually opposite relationship in the direction of the transverse axis and being inclined to converge towards each other in a direction away from said transverse axis,
• said contact surface being arranged between said first and second lateral support surfaces the spacing of which allows each still transversely cambered portion of the strip to enter between said support surfaces and to be conformed to said contact surface, whereby said portion of the strip is subjected to an increase in width when its transverse camber is reduced,
• wherein said two narrow side surfaces of said strip are inclined at an angle such that the inclination of said narrow side surfaces of any portion of said strip at least substantially corresponds to the inclination of said lateral support surfaces when such a portion of the strip bears against said contact surface,
• whereby said portion of the strip is gripped immovably in a resiliently reversible manner between said contact surface and said lateral support surfaces in such a manner that said guiding apparatus can take any pressure load which is applied to said strip in its longitudinal direction towards said guiding apparatus.