Web threading apparatus for rotary printing machines
AssigneeMAN Roland Druckmaschinen AG
InventorsIngo Kobler, Johann Winterholler
Life of this patent
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Abstract
To prevent jamming of a threading roller chain being pushed against the teeth of a sprocket wheel which, in advance of being driven, is still stationary, a portion of the guide rail guiding the roller chain (11) and opposite the sprocket wheel (24) is formed to be resiliently deflectable, for example by including a rocker element (36) or a resilient track portion (51, 52), the rocker element or the resilient track portion being maintained by a spring (46, 55) in normal, undeflected position, but permitting deflection, the spring means returning the resiliently deflectable portion to aligned, undeflected position upon proper feeding and threading of the roller chain.
Claims11
In combination with a rotary printing machine a web threading apparatus for use in the rotary printing machine comprising
- a track (12) having guide rails, including an inner guide rail (15), and an outer guide rail (14) parallel to the inner guide rail and spaced therefrom;
- a roller chain (11) having a leading end, positioned in said track, sliding on at least one of said guide rails, guided by the guide rails, and having attachment means (13) for attachment thereto of a web (9) of material to be threaded into the printing machine,
- and a sprocket wheel (24) adapted to receive the leading end portion of the chain and to then engage in the links between the rollers of the roller chain, said sprocket wheel extending through one of the guide rails into the space between both of the guide rails (14, 15) of said track in a section thereof,
- and means to permit reliable interengagement of the sprocket wheel projecting in the space between the guide rails with the leading end portion of the chain, said means including a movable rail element (36) located in said section, and
- spring means (46) retaining said movable rail element in a normal position forming a continuation of the outer guide rail of the track and capable of resilient deflection in a direction transverse to the direction of movement of the chain when the chain is being fed in the track toward the sprocket wheel for engagement with the leading end portion of the chain, and being returned from deflected position to permit reliable interengagement of the sprocket wheel with the roller chain regardless of relative position of the chain and sprocket wheel upon initial contact therebetween.
In combination with a rotary printing machine, a web threading apparatus comprising
- a track (12) having guide rails including an inner guide rail (15), and an outer guide rail (14) parallel to the inner guide rail, and spaced therefrom;
- a roller chain (11) having a leading end, positioned in said track, sliding on at least one of said guide rails, guided by the guide rails and having attachment means (13) for attachment thereto of a web (9) of material to be threaded into the printing machine,
- a sprocket wheel (24) adapted to receive the leading end portion of the chain and to then engage in the links between the rollers of the roller chain, said sprocket wheel having a portion extending through one of the guide rails into the space between both of the guide rails (14, 15) of said track in a section thereof;
- and means to permit reliable interengagement of the portion of the sprocket wheel projecting into the space between the guide rails with the leading end portion of the chain, said means including
- a track portion made of resilient, yielding material;
- parts of the outer guide rail being formed as resilient rail elements in the section of said track into which the sprocket wheel (24) extends, said parts being capable of resilient deflection in a direction transverse to the direction in which the chain is being fed, said parts being held in normal position in alignment with adjacent portions of said track and returned into normal, aligned position after deflection upon engagement with said roller chain and after having been subjected to a deflecting force, said rail elements being positioned symmetrically with respect to a theoretical line or axis (38) passing through the center of rotation of said sprocket wheel (24) and being positioned perpendicularly to a center line between the inner and outer guide rail of said track.
Dependencies are inferred from the claim text.