Patent · US Expired

Keyless entry system for automotive devices with compact, portable wireless code transmitter, and feature for preventing users from locking transmitter in vehicle

US4672375A · kind A · utility

83Cited by
11References
35Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 10, 1985
Grant dateJun 9, 1987
Priority date
Expiry dateApr 10, 2005

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T70/5978
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A keyless entry system allows operation of various vehicle devices including a door lock without using a mechanical key, such as an ignition key. The system comprises a wireless, portable transmitter adapted to produce a radio signal indicative of a unique code preset in the transmitter, and a controller mounted on the vehicle and associated with the vehicle devices. The controller has a preset code to compare with the unique code indicative in the radio signal transmitted from the transmitter. The controller also detects impending or accomplished locking of the transmitter in the vehicle and produces an alarm and subsequently disables the keyless entry system unless the transmitter is removed from the vehicle within a given period of time after the alarm is given.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.