| 摘要 |
<p>Apparatus is provided for achieving true and accurate feed of linear sheet material such as a recording or plotting medium in a strip chart type utilization device, particularly in applications where a high degree of feed accuracy is required. The apparatus comprises a roller which is mounted for engagement with the recording medium as it is fed from a supply spool to a take up spool. The roller is journalled at its ends for limited universal movement. A brake pad is associated with each journalled end of the roller, the brake pads being engageable with flanges on the supply spool. If, as it is being advanced, the recording medium drifts to one side then a small amount of slack will occur at the other side. This slack is detected by the roller causing the end which senses the slack to move towards the supply spool and thereby causing the brake shoe on that side to engage the appropriate flange to correct the drift.</p> |
