Abstract: An electrical receptacle consisting of a casing having a lock part to releasably lock a mating electrical plug of the blade contact type, is disclosed. The lock part is a separate piece made of electric insulating material and manually-operable release buttons externally of the casing. The lock part ensures an effective locking of the plug and eliminates any possibility of electric shock to a user while inserting or removing the plug contacts.

Abstract: A security device for a thermostat comprising a housing for said thermostat, a lid member secured to the housing for movement between an opened position and a closed position, to gain and prevent access to the thermostat, respectively. The thermostat has a rotatable thermostat adjustment shaft extending exteriorly of the housing for manual manipulation thereof. A lock member is mounted in the housing for movement between a first position whereat the lock member lockingly engages the adjustment shaft to prevent rotation thereof and engages the lid member to prevent opening thereof and a second position whereat the lock member is disengaged from the adjustment shaft and the lid member permitting manual manipulation of the shaft or opening of the lid member and a key-operated actuating member disposed in the housing and extending exteriorly of the housing for displacing the lock member between its first and second positions.

Abstract: The invention describes an electrical receptacle comprising a housing having apertures for receiving blade-type contacts of a plug in which the plug is formed with an aperture at its free end, and a pair of contacts secured in the interior of the housing in longitudinal alignment with the apertures for electrically conductively contacting plug contacts inserted through the apertures, each contact member having a flexible contact portion having a projection releasably interlockable with the aperture of a plug contact to prevent inadvertent withdrawal of the plug contacts from the housing and an arrangement for selectively manually displacing the contact portions for releasing the plug contacts.