![]() The field created by a permanent magnet would therefore be too weak to retain the outside cleaning element against the pane during the cleaning operation. In the prior devices, the magnet was located inside the window pane, and a pad containing a magnetically-permeable metal was used on the outside of the window pane. This is evidently due to the fact that a device incorporating permanent magnets and made according to the teachings of the prior art could not operate. Up to this time, there has been no evidence of a cleaning device of this type which was provided with permanent magnets, although the use of permanent magnets would enable such devices to be sold at a low cost. Y10T24/32- Buckles, buttons, clasps, etc.Y10T24/00- Buckles, buttons, clasps, etc. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |