Door closers with automatic latching or/and delayed action

A door closer comprising:

• an elongated cylinder having opposed ends,
• a partition disposed intermediate said elongated cylinder for defining therein a piston chamber and a delay chamber,
• a piston reciprocally mounted within said piston chamber,
• a piston rod connected to said piston,
• said piston rod extending through said delay chamber and beyond one end of said elongated cylinder,
• a compression spring disposed within said piston chamber between said partition and said piston for exerting a spring bias on said piston in a door closing direction,
• a free piston slidably mounted on said piston rod within said delay chamber and in sealing relationship therewith for relative axial movement toward and away from said partition within said delay chamber,
• whereby said free piston and partition define therebetween a variable delay cavity,
• said partition having means for metering the flow of a fluid medium between said delay cavity and said piston chamber to effect a time delay upon the closing stroke of the door closer.