Abstract: A door closer and holder has cylinders with pistons therein responsive to the relative swinging motion between a door panel and a door frame. A spring is loaded by door opening and acts against one piston to effect door closing. Various hydraulic passages opening into the cylinders have valves therein to control the door panel opening and closing speed or speeds. One of the valves, electrically operated, allows the door panel to close from a hold-open position.

Abstract: A hydraulic door closer is provided with a fluid seal for its output shaft, the seal comprising multiple O-rings disposed side-by-side in an elongated annular chamber.

Abstract: A modular door closure system comprises a rack and pinion motor assembly with single action opening 2a mounted in a first case 5a; a similar motor assembly with double action opening mounted in a housing element 5, 6; and a spring and shock absorber restoration drive 4 mounted in a second case 7 that can be assembled with either the first case 5a to constitute a single action door closure 1a, or with the housing element to constitute a double action door closure 1.

Abstract: A delayed action door closer that delays a portion of the closing of a door for an adjustably determined period of time after the door has been moved to its fully open position. An interdependent hydraulic speed control system utilizes a delayed action speed control regulating valve which controls the closing speed of the door in the delayed action zone only, and whose speed cannot be adjusted faster than the main closing speed, but can be adjusted to provide a desired delay time prior to the door closing under normal regulation. The placement of the interdependent hydraulic system in the checking end of the closer allows the closer to have a fully adjustable independent backcheck.

Abstract: Hydraulic door closer apparatus has associated with it means for counter-balancing the bias of a return spring, to assist in opening the door by reducing the force needed to open it, or to open the door by over-balancing the bias of the return spring. Remotely manually operable means may initiate opening of the door.

Abstract: A hydraulically controlled door closer in which a spring cooperating with a piston reciprocatable in a fluid filled bore urges a closer shaft operatively connected to the piston to a position in which a door connected to the closer shaft is closer. The spring is tensioned during turning of the closer shaft in a door opening direction and may be releasably held in the tensioned condition by an additional piston located between one end of the spring and the first-mentioned piston and provided with a first passage therethrough in which a one-way valve is located in a second passage which may be closed and opened by an electromagnetically operated valve.

Abstract: An automatic door closer constructed for releasably holding a door in a predetermined partly open position mainly comprises a piston arranged in a cylinder bore of a housing and operatively connected to a closer shaft mounted in the housing turnable about an axis substantially normal to that of the cylindrical bore so that the piston will be reciprocated in the bore during turning of a door connected to the closer shaft. The piston divides the bore in the housing in two compartments filled with fluid and a coil compression spring in one of the compartments biases the piston to an end position corresponding to the closed position of the door. The piston is provided with two passages therethrough, in one of which a one-way valve is arranged permitting flow of fluid only from the one compartment into the other during movement of the piston in door opening direction.

Abstract: Hydraulic door closer apparatus includes means for counter-balancing the bias of a return spring, to either assist in opening the door by reducing the force needed to open, or, in an alternative embodiment and mode of operation, to open the door by over-balancing the bias of the return spring. In the latter mode, a remotely manually operable switch, such as, for example, a so-called palm button, may initiate opening the door.

Abstract: An accessory for use with a conventional door closer having a body for mounting on a hinged door or the door jamb and a spring biased rotatable shaft constantly urging the door toward a closed position. The accessory comprises a first member having a reaction plate fixed with respect to the door closer body, a second member, such as an externally splined ring, fixed with respect to the door closer shaft, and a member, such as a flanged collar, rotatably interconnecting the first and second members. The collar is threaded into a hole in the reaction plate, and has an internally splined hole accommodating and meshing with the splined ring. The force of frictional engagement between the flange and the reaction plate progressively increases as the door is opened, and at an adjustable predetermined open position of the door the frictional resistance between the flange and reaction plate is stronger than the closing force of the door closer, so that the door is held open.

Abstract: A door closer for moving a door connected thereto from an open position to a closed position includes a housing, a chamber located within the housing, a piston movable in the chamber in response to movement of the door and a linkage assembly connected to the door for transmitting door movement from the door to the piston. A fluid chamber is disposed on one side of the piston and the piston moves through the fluid chamber upon closing movement of the door. Valve means is provided for controlling the rate of fluid flow from the fluid chamber as the piston moves therethrough to thereby control the rate of movement of the piston and the damping force acting on the door. A spring is disposed in the chamber and acts on the piston to provide a force to move the door toward the closed position.

Abstract: A door operator mechanism includes a spring biased piston 5 having a non-return valve 6 in its end face slidably disposed in a hydraulic cylinder 3 and coupled to a door lever arm through a pinion shaft 11, a pinion gear 9, and a tooth rack 7 on the piston. If the door is opened beyond a normal angle a rod member 16 disposed within the spring 4 engages and compresses a resilient member 15 disposed between one end of the cylinder and the spring. The resilient member has a higher coefficient of resiliency than the spring and thus is not initially compressed thereby, and its restraining force increases sharply at high compression ratios, to thereby increasingly resist door overtravel.

Abstract: A door closer includes a cylinder-and-piston arrangement in which the piston is received in the cylinder for displacement between a rest position corresponding to a closed position of the door, and an end position corresponding to the fully open position of the door, through an intermediate position corresponding to a partly opened position of the door. The piston subdivides the interior of the cylinder into at least two compartments which are in communication with one another via at least two passages one of which is closable in any position of the piston by means of an electromagnetically operated valve, the other passage being open when the piston is between the rest and the intermediate position and closed when the piston is between the intermediate and the end position.

Abstract: Hydraulic door closer apparatus comprises a cylinder and an elongated piston disposed in the cylinder, the piston being made of relatively easily machined material, but having associated with it a rack of harder, wear and impact-resistant material for transmitting forces and motion to and from the piston.

Abstract: A door closer has an air cylinder which, when pressurized, neutralizes the door closing force applied by the closer so that the door will open with relative ease. The air cylinder is pressurized through a valve which is contained within the door and is operated by a handle on the door.

Abstract: An adjustable spring loading mechanism for use in controlling the movement of doors and the like. The mechanism includes a cylinder housing and a piston slideable within the housing. A plurality of biasing means are arranged in the housing in engagement with the piston, and apply individual biasing forces to the piston which cooperate to produce a total resultant biasing force. The biasing means are provided with different effective lengths so as to engage with the piston at different positions in the cylinder and thereby vary the total biasing force.