Imprinter

In an imprinting apparatus using an imprint ribbon for permitting imprinting of data on a weblike packaging substance, said apparatus including a frame, spool-supporting shaft means rotatably supported on the frame and mounting thereon a spool of said ribbon, take-up reel means rotatably mounted on the frame for winding therearound the used ribbon, guide means disposed for movably guiding the ribbon in a preselected path as the ribbon is withdrawn from the spool and is moved toward said take-up reel means, said guide means maintaining said ribbon straight during a selected part of said path, imprinting means associated with said selected part of the ribbon path for effecting imprinting on said weblike packaging substance, said imprinting means including stationary and movable pressing heads having opposed faces disposed on opposite sides of said ribbon as located in the selected part of said path, said movable pressing head being slidably guided for linear displacement in a direction substantially perpendicular to said ribbon, said movable pressing head also having type means associated with the face thereof, and motor means connected to said movable pressing head for linearly reciprocating same between extended and retracted positions, said movable pressing head when in said extended position being disposed in pressing engagement with said stationary pressing head so as to press said ribbon and said weblike packaging substance therebetween, said movable pressing head when in said retracted position being spaced from both said stationary pressing head and said ribbon, the improvement comprising:

• a rotatable drive roller disposed in direct driving engagement with said ribbon downstream of said imprinting means but upstream of said take-up reel means for effecting displacement of said ribbon along said path, and withdrawal of ribbon from said spool, in response to rotation of said roller;
• primary motion-transfer means drivingly connected between said movable pressing head and said drive roller for causing intermittent unidirectional rotation of the latter in response to reciprocating movement of said movable pressing head, whereby said ribbon is intermittently and unidirectionally movably displaced along said path through a preselected distance;
• said primary motion-transfer means including one-way means for effecting intermittent unidirectional rotation of said drive roller only when the movable pressing head is being linearly displaced in one direction, said one-way means enabling the drive roller to remain stationary when the movable pressing head is being linearly displaced in the opposite direction;
• said primary motion-transfer means also including a linear gear rack mounted on said movable printing head and disposed in meshing engagement with a rotatable gear, said rotatable gear being drivingly interconnected to said drive roller through said one-way means;
• said primary motion-transfer means further including lost-motion means associated therewith for permitting at least limited linear displacement of the movable pressing head in said one direction without causing a corresponding rotation of the drive roller, whereby said lost-motion means results in the rotation of the drive roller occurring over only a fraction of the stroke of the movable pressing head in said one direction;
• said lost-motion means comprising connecting means coacting between said gear rack and said movable pressing head for permitting limited relative reciprocal movement therebetween in a direction substantially parallel to the direction of movement of said movable pressing head, biasing means coacting with said gear rack for normally maintaining same in an end position relative to the movable pressing head, and stationary stop means positioned for engagement with said gear rack to movably displace same against the urging of said biasing means when said movable pressing head is positioned at or closely adjacent said extended position;
• and
• secondary motion-transfer means drivingly connected to said take-up reel means for causing intermittent unidirectional rotation thereof.