| 摘要 |
<p>Apparatus for making holes in a web of photosensitive material which is transported in a copying machine has an electromagnet with a reciprocable armature connected to one leg of a U-shaped carrier. The other leg of the carrier supports a material removing tool which penetrates through the web when the electromagnet is energized. The carrier is held against wobbling by a ball bearing which is connected to its one leg and extends with minimal clearance between two parallel guide faces which are machined into a stationary holder for the electromagnet. The holder has a plate-like extension with a hole which receives the tip of the tool subsequent to penetration of such tip through the web. The tool is normally located at one side of the plane of the web, and the extension is located at the other side of such plane. The clearance between the bearing and the guide faces is less than that clearance which would permit such lateral movement of the tool that the latter would fail to penetrate into the hole of the extension in response to energization of the electromagnet.</p> |
