Method of making article having relatively moving members
Abstract
Abstract A die casting process for forming an article having first and second elements intercoupled for pivotal or sliding movement. A first element is formed, as by casting, and the second element is cast with the bearing region of the first element forming a mold for the bearing region of the second element. The casting may be effected in movable dies, with the elements being moved either linearly or arcuately to the different die positions for sequentially casting the first and second elements. Freedom of the joint between the two elements is obtained by stressing the first element before the second element is cast thereabout, so that upon placing of the casting process the bearing regions of the first element spring back to their original position to enable free pivotal or sliding movement between the elements. The process is advantageously employed to fabricate a door knocker, with the U-shaped striker being the first formed element and the striking plate being the second formed element, the U-shaped striker being compressed prior to casting of the striking plate, in order to ensure free pivotal movement of the striker. The striking plate has a rear surface with a first substantially flat portion and a second portion in a plane parallel to and spaced therefrom, to enable the flat portion to be adhesively affixed to a door by means of a resilient pad, with the second portion contacting the door to ensure acoustic coupling between the striking plate and the door.
Inventors
- 👤 Ruediger Einhorn
Bibliographic Details
Claims Analysis
Total Claims: 8References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |