|
| US4054935 | 28 mai 1976 | 18 oct. 1977 | | Safety control circuit |
| US4412268 | 2 oct. 1981 | 25 oct. 1983 | Dart Industries Inc. | Safety switch system for industrial machines |
| US4918560 | 29 juil. 1988 | 17 avr. 1990 | | Proximity operated machine control |
| US4939358 | 23 mai 1988 | 3 juil. 1990 | Jeffries, Inc. | Switch apparatus including a pair of beam-type switches |
| US5077467 | 12 sept. 1990 | 31 déc. 1991 | Triad Controls, Inc. | Photoelectric switch and relay system with disabling fail-safe monitoring circuitry |
| US5235217 | 24 juil. 1991 | 10 août 1993 | ISB Ltd. | Capacitive press control actuation system |
| US5341036 | 11 déc. 1991 | 23 août 1994 | Square D Company | Two hand operated machine control station using capacitive proximity switches |
| US5347421 | 17 déc. 1992 | 13 sept. 1994 | | Law energy solenoid energizer |
| US5367158 | 25 oct. 1991 | 22 nov. 1994 | Break-A-Beam, Inc. | Photoelectric switch for use with a machine control circuit |
| US5665961 | 26 oct. 1994 | 9 sept. 1997 | Break-A-Beam, Inc. | Photoelectric switch for use with a machine control circuit |
| US5912795 | 3 déc. 1996 | 15 juin 1999 | Ross Operating Valve Company | Circuit reset lockout |
| USRE37777 | 19 déc. 1997 | 2 juil. 2002 | | Switch apparatus requiring the hand of the operator to activate the switch by breaking a light beam |
