| 摘要 |
A ribbon tensioning assembly includes a knob having a top wall, an internal raised portion attached to the top wall having a first helical camming surface and a second helical camming surface out of phase and disposed about a center point. A compression helix has a first end portion forming a first helical camming surface and a second helical camming surface for engaging first and second helical camming surfaces of the knob, compression helix having a second end portion for receiving a spring. A clutch engages a surface and connects to a spring. A spindle, attaching to a ribbon supply roll, secures the knob, the compression helix, the spring and the clutch in relative position such that turning the spindle causes frictional resistance between the clutch and the surface for creating increased tension in a ribbon dispensed from the supply roll.
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