| 摘要 |
In a print head assembly for calculators and the like, the print head is reversibly driven in a print and return direction transversely of the direction of advancement of the recording medium by a drum segment having a cam drive in the form of an endless helical groove which extends along a cylindrical surface of revolution between opposite ends of a drive axle mounted in driving relation to the print head so that rotation of the drum will impart translational movement to the print head through a suitable drive member engaged by the helical groove at a preselected rate of speed both in the print and return direction. |
