| 摘要 |
<p>An electromagnetic door holding device for a door closer of the type having a spring operated rotating spindle operatively connected by an arm to a slider mounted for reciprocal movement in a track usually secured to the door frame wherein the slider has a cam which when the door is swung to a fully opened position engages and is held by an electromagnet against movement relative to the slider when the door attempts to return to a closed position and which engages and moves a detent carried by the slider into engagement with detent engaging means in the track so as to prevent movement of the slider relative to the track and thus releaseably hold the door in the open position. The energizing of the electromagnet allows the spring to move the cam out of engagement with the detent and thus permit the slider to move and enable the door to move to a closed position.</p> |
