Car key hole bolt fastening assembly
US4121495A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 1, 1976 |
| Grant date | Oct 24, 1978 |
| Priority date | — |
| Expiry date | Mar 1, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S411/999
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An assembly is provided for blind hole mounting an external appurtenance including safety appliances such as ladder rungs, hand holds, and walkways on a railway freight car. One or more key hole slots are provided through the surface of the car where the external appurtenance is to be mounted. Each slot includes an enlarged bolt head receiving portion through which the head of a fastening bolt may be inserted and a key portion of smaller size forming a continuation of the slot into which the shank of the bolt may be slipped for retaining the fastening bolt in the slot. The relative dimensions of the bolt head and the bolt head receiving portion of the key hole slot are such that the bolt head can only pass through the bolt head receiving portion of the key hole slot when the bolt head is first inserted edgewise through the bolt head receiving portion and the bolt then rotated to a perpendicular position relatively to the key hole slot. The bolt shank has a movable retainer thereon of a size to cover a portion of the key hole slot and prevent the bolt from dropping through the blind hole both during insertion through the bolt head receiving portion of the key hole slot and during su…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.