Patent ID: 8307495

Claim:
A door cylinder comprising: (a) a tubular housing closed at a first end; (b) a rod having a piston at a first end and bracket engaging means at a second end, slidably mounted within the housing for movement from an extended to a retracted position; (c) a piston spring mounted over the rod for biasing the rod within the housing in a retracted position; (d) a rod end cap including a rod guide mounted within the open end of the housing with the rod slidably extended through the rod guide; (e) a hold open bracket slidably mounted on the rod for movement between a neutral and engaged position for releasably securing the position of the rod with respect to the housing; (f) a pair of bracket springs slidably mounted on the rod on opposite sides of the hold open bracket for biasing the hold open bracket in its neutral position to permit movement of the rod with respect to the housing; (g) a cover slidably mounted over the rod end cap including means for directly engaging the hold open bracket to cause the hold open bracket to move to the engaged position; (h) a sleeve positioned on the rod adjacent the piston; (i) a release pin slidably mounted on the rod end cap for movement between a neutral position extending into the tubular housing from the rod end cap and a released position partially extended outward from the rod end cap; and (j) a release pin bias means for biasing the release pin in its neutral position; wherein upon movement of the piston to its extended position, the sleeve will be drawn into engagement with the release pin, causing the release pin to slide into engagement with the hold open bracket to prevent the hold open bracket from being moved to or maintained in its engaged position when the rod is fully extended.