Abstract: An overhead door closer comprising including a housing, an output shaft with a cam disc, which shaft is rotatably movable supported in the housing, a link-plate carriage with two rotatably movable pressure rollers supported in the link-plate carriage, wherein the pressure rollers roll on the cam disc, a piston which is linearly guided in the housing, a piston rod which with one end is connected to the link-plate carriage, and with the other end is connected to the piston, and a closer spring, which, on the side of the piston facing the link-plate carriage, abuts at the piston.

Abstract: A floor-concealed door closer includes a housing for holding a door closing mechanism having an axle, and a housing cover for mounting on the housing and supporting the axle. The housing cover has transverse sides provided with lateral projections, each lateral projection having a stiffening flange.

Abstract: The invention relates to an electrical or electromechanical hold-open device, particularly for doors, which is displaceable within a sliding rail, the sliding rail comprising a lower chamber and an upper chamber, a power supply unit being disposed in the upper chamber and a slide member with a holding mechanism and a retaining mechanism being disposed in the lower chamber. This measure is intended to provide an electrical or electromechanical hold-open device which, compared to prior art hold-open devices, is improved particularly with regard to the power supply.

Abstract: A floor-concealed door closer includes a housing for receiving a door closing mechanism, and a housing cover suitable to be mounted on the housing. The housing cover has a receiving groove on its inside surface facing the housing for receiving a seal. In order to mount the housing cover on the housing with fewer screws than in previous models while maintaining the impermeability between the housing and the housing cover, the depth of the receiving groove varies over its length.

Abstract: A floor spring includes a housing for receiving a closing mechanism having a closing shaft. The closing shaft can support a door, and the housing has a region surrounding the closing shaft. The floor spring further includes a cover component for covering the region surrounding the closing shaft. The cover component has an essentially U-shaped base unit, and an insert which is insertable into the base unit.