Safety door stopper

A safety device in the form of a door stop adapted for positioning in an opening in a surface adjacent a movable door and adapted to move from a retracted position wherein said door may move therepast to an extended position wherein said door movement is prevented, said door stop comprising an outer cylindrical housing having upper and lower ends, said upper end being open and adapted for positioning substantially flush with said surface, an inner member having an outer cylindrical surface, said inner member positioned to telescopically slide in free rotational relation to the inner surface of said outer cylinder between said retracted and extended positions, said inner member having an enlarged annular lower end positioned to slidably contact said outer cylinder inner surface so as to function as lower guide means, and said outer cylinder open upper end including means for slidably contacting said inner member and acting as upper guide means, spring means for continually urging said member upwardly to its extended position wherein it projects above said outer cylinder upper end so as to contact and block said movement of said door, positioning means inwardly extending from said outer cylinder at an intermediate location between the ends thereof, said inner member including outwardly biased detent means adapted to extend from the outer surface thereof at an intermediate point thereof and engage undersurface portions of said positioning means such that said member is retained in said retracted position, said member downwardly movable against the action of said spring means by pressure applied to the top thereof such that sudden release thereof enables said detent means to move past said positioning means to its extended position wherein said enlarged lower end of said member positively contacts said positioning means so as to prevent further upward movement of said member by said spring.