Worklight with thermal warning
US7028634B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 25, 2001 |
| Grant date | Apr 18, 2006 |
| Priority date | — |
| Expiry date | Apr 9, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21V15/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An enhanced built-in visual warning mechanism to caution a user when the surfaces of a worklight are hot. A worklight is shown that has a housing that includes an interior portion for holding a light source such as one or more quartz halogen bulbs. The light source operates at a temperature sufficient to raise at least portions of the exterior surfaces of the housing to a temperature that is hot to human touch during normal operation of the worklight. A thermochromic substance is disposed in thermal communication with at least a portion of one of the exterior housing surfaces in a readily visible position. The thermochromic substance is formulated to undergo a conspicuous color change, in the normal operation of the worklight, in response to heat from the external surface where it is located. The dynamic color change provides a timely visible indication to the user that the exterior surface is presently hot to the touch. In some embodiments a thermal moderator is introduced between the hot worklight surface and the thermochromic substance to moderate the heat level applied to the thermochromic substance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.