Andy Jackson began Builders Brass Works in the early 1950’s making high end, high quality door pulls, dome stops, kick plates, hinges, flush bolts and various other types of door hardware for the construction industry. He knew that quality would be a key ingredient of his success. To ensure this level of quality, Mr. Jackson knew he had to keep control over what he produced. To this end, he opened his own foundry in East Los Angeles, Calif. Over the years, his company flourished.
Before long, he expanded the product line and began making the 10 Series cross bar design exit device. The 10 Series, designed for glass aluminum storefront doors, is available in rim and concealed vertical rod versions. These exit devices are suitable for use on narrow and wider stile doors.
While attending a tradeshow in Europe, Mr. Jackson saw a floor closer, the design of which intrigued him. At that time, the aluminum storefront industry in America was coming into its own and Andy envisioned an opportunity. He determined that, with a few modifications, that floor closer could be reversed and concealed in the aluminum transom above a storefront door. With that thought, he created the concealed overhead (transom) door closer.
Mr. Jackson formed a new company to market these two newly developed products – the 10 series exit device and the transom door closer (for some unknown reason identified as the 20-330 Series) – and the Jackson Corporation was born. Over the years, the product range has expanded to include a full range of overhead concealed door closers, exit devices and access control products.
Andy died in 1970. Approximately eight years later, the Jackson Corporation was sold to Thomas Industries. Thomas Industries kept Jackson and Builders Brass until the early 1990s, at which time the companies were sold to the current owners. Builders Brass was sold off and the Jackson Corporation began to focus its energy and resources on its core product group: access control products, exit devices, door closers and the related accessories.
Jackson makes all its products in East Los Angeles. The only exceptions are the 900 series floor closers, made by its sister company in the United Kingdom.
For the purpose of this article, we will discuss the operation; models and the different applications for Jackson concealed overhead door closers.
The Jackson overhead concealed door closer develops its closing force through the use of two springs that operate in unison. Each spring operates a piston within this closed system filled with hydraulic (transmission) fluid.
A single directional ball valve opening is in the center of each piston. At the rear end of the piston, there is a round opening just smaller than the diameter of the ball bearing swedged into place. At the front end is a clover leaf opening small enough to stop the ball bearing from escaping, but large enough for the fluid to move from the rear of the piston through this opening in the piston and out into the forward end of the closer. At rest, when the door is closed, the springs are expanded (most models) within close proximity to the screw caps.
As the door swings open, the springs begin to compress, hydraulic fluid forces the ball bearings moved forward against the clover leaf opening. The hydraulic fluid flows around the ball bearings through the clover leaf openings into the areas created by the compression of the springs.
Once the door has been opened and is beginning to close, the springs want to expand. The movement of the fluid that flowed through the single direction ball valve wants to flow in the opposite direction. This fluid forces each ball bearing in the opposite direction, against the smaller diameter opening in the rear of each piston. The result is the ball bearings seal the openings, stopping fluid from flowing back into the reservoir. Since hydraulic fluid is not really compressible, the fluid must move out of the cavity for the springs to expand, closing the door. To move the fluid and close the door, a second valve restricts the amount and speed of fluid flow back to the reservoir, controlling the closing of the door.
Cross holes at the forward end of the closer case connect to one or more valves that adjust the amount of flow into a port hole, which ends at the reservoir. Over the years these closers have evolved. Originally, one valve controlled both sweep and latch. Now there are two – one controlling each function – and. depending upon the configuration of the closer, a third valve that controls a hydraulic back check.
The length of movement of the springs’ compression, determines the swing of the door. Jackson overhead concealed closers are available with a swing of 90 degrees, 105 degrees or 120 degrees opening. The size of the fixed springs determines the opening force and affects the maximum flow of hydraulic fluid. The fixed spring sizes are Extra Light Duty (XLD), Light Duty (LD), Regular Duty (RD), and Heavy Duty (HD).
Jackson 20-330 Series Overhead Concealed Closers are manufactured under ISO 9001 guidelines. The 20-330 is non-handed, single- or double-acting, and can accommodate center hung or offset applications. There are three different types of overhead concealed closers. Jackson uses color coding to identify them: brown, blue and black. All three of the closers are the same shape and size.
The standard (brown) overhead concealed closers come in four different fixed spring sizes and are available having a 90-degree or 105-degree opening. These standard closers are available with hold open or non hold open.
The adjustable spring power (blue) overhead concealed closers come with springs that can be adjusted from 4.5 lb to about 15 lbs. Jackson springs are both compressed at the same rate making the unit more consistent and increasing durability. Adjustability is particularly important when trying to accommodate the balance between stack pressure within a building and Americans with Disabilities Act (ADA) codes. Closers leave the factory set at size Light Duty for a 7’0” by 3’0” door. To change force one size takes approximately four turns. To decrease pressure, turn counterclockwise. To increase pressure, turn clockwise. This closer is also available as a 90-degree or 105-degree hold open or non hold open.
Jackson has introduced a unique variation of the overhead Concealed adjustable closer called the “Easy OpenTM,” essentially an adjustable overhead concealed closer equipped with an 110VAC motorized mechanism that changes the spring pressure. The “Easy Open” is normally operated by pressing a momentary switch.
At rest, the “Easy Open” is normally set to between 8 and 10 pounds opening force. Pressing the momentary switch activates the “Easy Open.” The motor adjust the closer opening force down to approximately five pounds, making opening the door ADA compliant and meeting state codes that require minimum opening force. Once the door has been opened for a pre-set time, the motor begins to readjust the closer to the approximate eight- to ten-pound opening force. This does not affect the closing operation of the reduced force opening. However, once the door has been closed, the door will return to the preset opening force helping to offset any stack pressure within the building.
The Grade One (black) overhead concealed closers have been tested to ANSI Grade 1 standards (2 million cycles). These Grade One closers are available with hydraulic backcheck. They are available as 90-degree, 105 degree or 120 degree opening and with hold open or non hold open.
The overhead concealed door closer also acts as the top pivot for the operation of the door. The door is connected to the closer with an arm that is either offset or center hung. Center hung doors are mounted to the closer spindle using either an End-Load Arm or a Side-Load Arm. The way the door is attached is determined by the cut-out at the top of the door - end load arms are installed on the butt edge of the door and side load arms on the side or face of the door.
There are three different styles offset arms for single acting doors. One arm has no pre-load. A second arm has 1-1/2 degree pre-load, and the third arm has 2-1/2 degree pre-load. “Preload” means the closer (arm) continues to place pressure against the door even when the door is closed helping it to stay shut.
Offset closers typically do not open a full 90 degrees, but Jackson has developed a method of installation that does create a 90 degree opening. Instructions are in the overhead concealed closer box or you can call customer service for details. Jackson also has a closer with a hole drilled through the spindle to accommodate wires (so they don’t show) for various electrified door configurations. The part number is 20-151M.
There are two styles of slide channel assemblies. The standard channel is 1/2” thick, and the deep slide channel assembly is 25/32” thick. The variation is to accommodate a wider overhead rail.
To determine the overhead concealed closer spring size required for a specific application, Jackson has determined approximate opening force (in pounds) the different spring size door closers exert, depending upon the size of the door.
These charts are based upon calculations using a standard aluminum glass storefront door whose height is seven feet. The door width ranges from 2’6” to 4’0”. Recommendations are based on average conditions. Tall doors or stack pressure may require a larger fixed spring or adjustable closer.
NOTE: An auxiliary floor or overhead door stop is always recommended to prevent structural interference and possible door and closer damage due to over-extension of maximum allowable door swing.
Jackson 20-330 Series Overhead Concealed Closers are available as closer mechanism only or standard packages. A standard package includes closer mechanism, mounting brackets, arm package and bottom pivot.
Jackson has always been at its present location, 3447 Union Pacific Avenue, East Los Angeles, CA 90023. For more information, contact your local locksmith wholesaler or Jackson Corporation, Phone: 877-394-8338. Fax: 800-888-6855. Web site: www.jacksonexit.com.
Bob Ward is the Sales and Marketing Manager for Jackson.
