Security time clock system
US4837584A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 1988 |
| Grant date | Jun 6, 1989 |
| Priority date | — |
| Expiry date | Jan 4, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41M3/142
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
System for requiring the contemporaneous application of time clock data and personal data to a time card to prevent or signal the fraudulent application of either type of data at a time which is substantially different from the other type of data, i.e., by up to about 15 minutes. The present system includes the use of time cards having at least one color-forming chemical which may be in the form of a discontinuous coating, time clock transfer elements which may be coated with at least one complimentary color-forming chemical, pre-application of a liquid coating to the data-receiving area of the time card, which liquid coating permits the desired color-forming reaction only while it is liquid and which dries under ambient conditions before about 15 minutes, and the use of a signature-applying implement containing a special ink including at least one color-forming chemical and/or a mixture thereof with a transparent dye or pigment. The special ink forms multi-colored signatures when applied to the discontinuous time card coating, according to a preferred embodiment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.