Extension ladder
US3948353A · kind A · utility
9Cited by
6References
6Claims
0Family size
Inventor
Key dates
| Filing date | Mar 20, 1974 |
| Grant date | Apr 6, 1976 |
| Priority date | — |
| Expiry date | Mar 20, 1994 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE06C1/12
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An extension ladder in which the extension part has a plurality of striated cut-out portions along the leaning edge to serve as hooks for hooking onto a gutter or top edge of a sidewall or roof of a building to prevent lateral or vertical sliding. A lining of rubber or similar material is preferably provided in the cut-out portion to provide an anti-skid surface to further prevent lateral sliding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.