Abstract: A door closer comprising a housing, a member for driving engagement with a door, the member being rotatable relative to the housing in a door opening direction and in a door closing direction, a spring apparatus within the housing providing a resilient bias, the resilient bias being increased by rotation of the member in the door opening direction and a check device for controlling rotation of the member in the door closing direction and hence closure of the door under the action of the spring apparatus, the door closer having a back check comprising a piston member movable in a cylinder from an initial position against resistance of a fluid medium by rotation of the rotatable member in the opening direction.

Abstract: A door closer comprising a housing, a member for driving engagement with a door, the member being rotatable relative to the housing in a door opening direction and in a door closing direction, a spring apparatus within the housing providing a resilient bias, the resilient bias being increased by rotation of the member in the door opening direction and a check device for controlling rotation of the member in the door closing direction and hence closure of the door under the action of the spring apparatus, the door closer having a back check comprising a piston member movable in a cylinder from an initial position against resistance of a fluid medium by rotation of the rotatable member in the opening direction.

Abstract: A door closer has a cam and follower mechanism for transmitting movement between a spring and an operating member which is connected with a door. Guide elements for the cam follower can be adjusted relative to a housing to adjust the orientation relative to the housing to which the operating member is urged by the spring.

Abstract: A door closer comprises a housing containing a cylinder and two movable pistons. When the associated door is opened, both of the pistons and the cylinder are moved relative to the housing to draw oil into the cylinder. Expulsion of oil from the cylinder through an orifice on closing of the door controls the closing movement.

Abstract: A piston for a door closer comprises metal cups on opposite ends of a stem. A plastics ring is a snap-fit in one of the cups and protrudes from that cup to seal against the wall of a cylinder. A groove in the side wall of the cup for receiving a rib on the ring is formed by pressing a substantially flat blank before the blank is formed into the cup.

Abstract: A hinge for use with a fire door has a blade in which there are formed a number of screw holes and a larger opening. The larger opening is filled with an intumescent material.

Abstract: The piston of a door control device is assembled from a channel and cups welded on to opposite ends of the channel. A valve assembly is mounted in one of the cups. Rollers extend between opposite sides of the channel and co-operate with teeth on a rotatable member to which a control arm is secured.

Abstract: The piston assembly of a hydraulically controlled door closer has a tubular wall, plugs secured in end portions of the wall and a separate rack secured inside the tubular wall between the plugs by formations on the plugs.