Active Coils: The number of working coils in a torsion spring.
Air Infiltration: The leakage or passage of air through a door system.
Backroom:Horizontal distance measured into a building from the face of the header above an overhead door.
Black: Color-marking convention to mark parts as Right Side, Left Wound.
Bottom Corner Bracket: A structural support located on the bottom section that holds track rollers and may also provide for attachment of lifting cables.
Bottom Weatherseal: Weather-strip attached to the bottom rail of a door to seal against the floor.
Bracket Mounted: Method of fastening vertical track to jamb using angle brackets.
Cable Clamp: Manufactured device used to secure two pieces of cable to each other.
Cable Drum: Grooved drum, fitted on torsion spring shaft, onto which lifting cable is wound when door is opened.
Cable Length: Specific amount of cable required to properly operate door.
Ceiling: Top horizontal surface in the interior of an overhead.
Center Bearing Bracket: A bracket that houses a shaft bearing and is used to align and support the counterbalancing mechanism to the torsion shaft as well as anchor one end of torsion springs to the header.
Center Hinge: A hinge generally located on the intermediate stiles to allow sections to pivot as door opens. Also used as graduated edge hinge between bottom and intermediate section.
Center Stile: Vertical member of a door section which provides structural rigidity and location for center hinge attachment.
Clearance: The amount of side room, head room and back room required to properly install a sectional door.
Commercial: An overhead type door which is intended use at entrances of buildings such as loading docks and service stations, and is normally operated 5,000 cycles per year.
Counterbalance: To oppose or balance with an equal weight or force
Cycle: One complete cycle of a door beginning with the door in the closed position, then moving to the open position and back to the closed position.
Cylinder: The part of a key operated lock that accepts the key and contains the locking pins.
Daylight Opening: Opening dimensions taken between face of jambs and between and between floor and header.
Design Wind Load: Horizontal design applied to an overhead door based on such factors as wind speed, building height and door horizontal location.
Door Frame: The frame into which the door fits; consists of two door jambs, and a door header.
Door Header: The upper part of a door frame, consisting of the head jamb, heading casing, stop and trim molding.
Door Jamb: The upright framing on each side of the door opening.
Door Size: Door dimensions characterized by the width first and the height second.
Duplex Spring: A combination of two torsion springs of different diameters telescoped within spring fittings.
End Bearing Plate: Plate commonly used on torsion spring counterbalance units, which includes a ball bearing to support radial movement of a torsion shaft at each end.
End Stile: Stile located at each end of a door section which provides for attachment of graduated edge hinges.
Extension Spring: Provides power of tension by stretching or pulling, and is usually mounted along the horizontal section of track extending from front of door opening to the back hang.
Front Mounted Low Headroom: Low headroom hardware where springs mount on torsion shaft above opening.
Graduated Edge Hinge: Hinge placed on edge of door sections allowing sections to pivot as door opens and closes. Hinges hold track roller and are graduated and numbered for correct placement to ensure flush fit of door against jambs when closed.
Gusset Plate: Hardware fastened to door header to help support the track assembly and spring assembly.
Hang Down: The amount of the door that hangs down from the door opening when the door is the open position.
Headplate: The supporting place for the lifting drum located in line with the outer edge of the door.
Headroom: Vertical clear space required inside above the door opening, and below the lowest ceiling obstruction, required for proper operation of the door and its hardware.
High Cycle Spring: Counterbalance springs with increased cycle life capability for high usage doors.
High Lift Drum: A cable drum contoured to balance a high lift door.
High Lift Track: Track and hardware that causes the door to rise vertically some distance above the top of the door opening before it levels out into a horizontal position.
High Moment Arm: Radium of a cable drum, including cable, at point of cable peel off from the drum.
Hinge: Hardware item that joins door sections together, and allows sections to pivot independent of each other.
Horizontal Radium: Section of track that transitions from vertical to horizontal track welded, bolted or riveted to the horizontal track and then bolted to the flag angle.
Horizontal Rise: The upward slope of the horizontal track which helps to start the door downward and helps maintain cable tension.
Horizontal Track: Track used in the horizontal segment of a track assembly
Horizontal Track Assembly: An assembly made up of horizontal track and reinforced with an angle that is used to both guide and support the door in the horizontal position.
Inch-Pounds: English unit of measurement of torque.
IPPT: Acronym for Inch-Pounds-Per-Turn; torque rate of a spring, indicating the number of inch-pounds of torque delivered to a shaft for each turn the spring is wound.
Jamb Brackets: “L” shaped bracket used to connect the vertical track to the door jamb.
Low Lift Hardware: Low headroom accessories which enable a door system to operate in minimal headroom conditions.
Low Moment Arm: Smallest radius, or distance from the shaft axis, to the center of the cable that regards cable peel off point on cable drums.
LSLO: Acronym for Left Side Looking Out
MIP: Acronym for Maximum Inch Pounds; (IPPT x Turns = MIP); Used to describe the total torque required on a shaft to rise a given door weight from the floor, and also is the measurement of the torque capacity of a particular wire size at a desired cycle level of operation.
Opening Height: Distance from floor to the bottom of header.
Opening Width: Distance between jambs of the door opening.
Perimeter Seal: Weather-strip installed at the perimeter of an overhead door.
Pounds Pull: Unit of force determined by dividing the torque by the moment arm of the drum.
Quarter Turn: A unit of turn measurement when winding tension into a torsion spring.
Rain Stop: Ledge provided at the point where the bottom rail meets the floor to prevent water from running under the door and allowing for runoff of the water onto the drive or approach.
Rate of Rise: Measurement of change per revolution of a drum’s moment arm.
Red: Indicates color for Left Side, Right Wound.
Residential: A sectional overhead type door which is intended for use in a residential garage, and normally operated less than 1,500 cycles per year.
Roller Bracket: A device that is mounted to a door section and holds a track roller.
RSLO: Acronym for “right side looking out”.
Sideroom: a horizontal measurement from each side of the door opening, outward to the nearest obstruction.
Slant: The pitch of a room.
Spring Assembly Closed Wound: A coiled torsion spring with no gaps between the coils.
Spring Assembly Open Wound: A coiled torsion spring with equal gaps between each coil.
Spring Balance: The amount of turns needed to counterbalance the weight of the overhead door.
Spring Fitting: A plug or cone used to adapt the torsion springs to the torsion shaft and/or center bearing bracket. One piece is a stationary cone while the other fitting is a winding plug.
Stationary Cone: Part that fits into the end of a torsion spring permitting the spring to be fixed to the center bearing bracket; may also incorporate a retainer for a ball bearing or bushing.
Top Seal: Weather-stripping which fastens to the top of the door to seal the door along the top of the opening.
Torque: The twisting force around an axis.
Torsion Spring: A spring that works in the manner of twisting one end or part about a longitudinal axis while the other end is held or turned in the opposite direction developing torque.
Track: Channel shaped metal bars or rails in which upward acting doors operate via track rollers.
Track Roller: Roller assembly for guiding the door sections along track.
Trajectory: The arc of travel or sweep of the top section as the door is raised from closed to open position.
Turn: A 360-degree revolution of a component about its axis.
Upper Vertical Track: Upper track assembly on a vertical lift door.
Vertical Lift: Refers to a hardware design that causes doors to open vertically where no horizontal tracks or required.
Vertical Lift Drum: A cable drum with changing radium grooves to negate spring tension.
Vertical Track: The portion of a track that is orientated vertically and is adjacent to the jamb.
Weather-strip: Material used at the perimeter of an overhead door, or between joints of an overhead door, intended to improve a door’s performance against air infiltration and thermal transmission.
Winding Cone: Part that fits into a torsion spring permitting winding and tension adjustment.
Winding Rod: A solid rod that fits into the socket of the winding plug to tension torsion springs.
Wire Size: The diameter of the wire in a spring.
Air Infiltration: The leakage or passage of air through a door system.
Backroom:Horizontal distance measured into a building from the face of the header above an overhead door.
Black: Color-marking convention to mark parts as Right Side, Left Wound.
Bottom Corner Bracket: A structural support located on the bottom section that holds track rollers and may also provide for attachment of lifting cables.
Bottom Weatherseal: Weather-strip attached to the bottom rail of a door to seal against the floor.
Bracket Mounted: Method of fastening vertical track to jamb using angle brackets.
Cable Clamp: Manufactured device used to secure two pieces of cable to each other.
Cable Drum: Grooved drum, fitted on torsion spring shaft, onto which lifting cable is wound when door is opened.
Cable Length: Specific amount of cable required to properly operate door.
Ceiling: Top horizontal surface in the interior of an overhead.
Center Bearing Bracket: A bracket that houses a shaft bearing and is used to align and support the counterbalancing mechanism to the torsion shaft as well as anchor one end of torsion springs to the header.
Center Hinge: A hinge generally located on the intermediate stiles to allow sections to pivot as door opens. Also used as graduated edge hinge between bottom and intermediate section.
Center Stile: Vertical member of a door section which provides structural rigidity and location for center hinge attachment.
Clearance: The amount of side room, head room and back room required to properly install a sectional door.
Commercial: An overhead type door which is intended use at entrances of buildings such as loading docks and service stations, and is normally operated 5,000 cycles per year.
Counterbalance: To oppose or balance with an equal weight or force
Cycle: One complete cycle of a door beginning with the door in the closed position, then moving to the open position and back to the closed position.
Cylinder: The part of a key operated lock that accepts the key and contains the locking pins.
Daylight Opening: Opening dimensions taken between face of jambs and between and between floor and header.
Design Wind Load: Horizontal design applied to an overhead door based on such factors as wind speed, building height and door horizontal location.
Door Frame: The frame into which the door fits; consists of two door jambs, and a door header.
Door Header: The upper part of a door frame, consisting of the head jamb, heading casing, stop and trim molding.
Door Jamb: The upright framing on each side of the door opening.
Door Size: Door dimensions characterized by the width first and the height second.
Duplex Spring: A combination of two torsion springs of different diameters telescoped within spring fittings.
End Bearing Plate: Plate commonly used on torsion spring counterbalance units, which includes a ball bearing to support radial movement of a torsion shaft at each end.
End Stile: Stile located at each end of a door section which provides for attachment of graduated edge hinges.
Extension Spring: Provides power of tension by stretching or pulling, and is usually mounted along the horizontal section of track extending from front of door opening to the back hang.
Front Mounted Low Headroom: Low headroom hardware where springs mount on torsion shaft above opening.
Graduated Edge Hinge: Hinge placed on edge of door sections allowing sections to pivot as door opens and closes. Hinges hold track roller and are graduated and numbered for correct placement to ensure flush fit of door against jambs when closed.
Gusset Plate: Hardware fastened to door header to help support the track assembly and spring assembly.
Hang Down: The amount of the door that hangs down from the door opening when the door is the open position.
Headplate: The supporting place for the lifting drum located in line with the outer edge of the door.
Headroom: Vertical clear space required inside above the door opening, and below the lowest ceiling obstruction, required for proper operation of the door and its hardware.
High Cycle Spring: Counterbalance springs with increased cycle life capability for high usage doors.
High Lift Drum: A cable drum contoured to balance a high lift door.
High Lift Track: Track and hardware that causes the door to rise vertically some distance above the top of the door opening before it levels out into a horizontal position.
High Moment Arm: Radium of a cable drum, including cable, at point of cable peel off from the drum.
Hinge: Hardware item that joins door sections together, and allows sections to pivot independent of each other.
Horizontal Radium: Section of track that transitions from vertical to horizontal track welded, bolted or riveted to the horizontal track and then bolted to the flag angle.
Horizontal Rise: The upward slope of the horizontal track which helps to start the door downward and helps maintain cable tension.
Horizontal Track: Track used in the horizontal segment of a track assembly
Horizontal Track Assembly: An assembly made up of horizontal track and reinforced with an angle that is used to both guide and support the door in the horizontal position.
Inch-Pounds: English unit of measurement of torque.
IPPT: Acronym for Inch-Pounds-Per-Turn; torque rate of a spring, indicating the number of inch-pounds of torque delivered to a shaft for each turn the spring is wound.
Jamb Brackets: “L” shaped bracket used to connect the vertical track to the door jamb.
Low Lift Hardware: Low headroom accessories which enable a door system to operate in minimal headroom conditions.
Low Moment Arm: Smallest radius, or distance from the shaft axis, to the center of the cable that regards cable peel off point on cable drums.
LSLO: Acronym for Left Side Looking Out
MIP: Acronym for Maximum Inch Pounds; (IPPT x Turns = MIP); Used to describe the total torque required on a shaft to rise a given door weight from the floor, and also is the measurement of the torque capacity of a particular wire size at a desired cycle level of operation.
Opening Height: Distance from floor to the bottom of header.
Opening Width: Distance between jambs of the door opening.
Perimeter Seal: Weather-strip installed at the perimeter of an overhead door.
Pounds Pull: Unit of force determined by dividing the torque by the moment arm of the drum.
Quarter Turn: A unit of turn measurement when winding tension into a torsion spring.
Rain Stop: Ledge provided at the point where the bottom rail meets the floor to prevent water from running under the door and allowing for runoff of the water onto the drive or approach.
Rate of Rise: Measurement of change per revolution of a drum’s moment arm.
Red: Indicates color for Left Side, Right Wound.
Residential: A sectional overhead type door which is intended for use in a residential garage, and normally operated less than 1,500 cycles per year.
Roller Bracket: A device that is mounted to a door section and holds a track roller.
RSLO: Acronym for “right side looking out”.
Sideroom: a horizontal measurement from each side of the door opening, outward to the nearest obstruction.
Slant: The pitch of a room.
Spring Assembly Closed Wound: A coiled torsion spring with no gaps between the coils.
Spring Assembly Open Wound: A coiled torsion spring with equal gaps between each coil.
Spring Balance: The amount of turns needed to counterbalance the weight of the overhead door.
Spring Fitting: A plug or cone used to adapt the torsion springs to the torsion shaft and/or center bearing bracket. One piece is a stationary cone while the other fitting is a winding plug.
Stationary Cone: Part that fits into the end of a torsion spring permitting the spring to be fixed to the center bearing bracket; may also incorporate a retainer for a ball bearing or bushing.
Top Seal: Weather-stripping which fastens to the top of the door to seal the door along the top of the opening.
Torque: The twisting force around an axis.
Torsion Spring: A spring that works in the manner of twisting one end or part about a longitudinal axis while the other end is held or turned in the opposite direction developing torque.
Track: Channel shaped metal bars or rails in which upward acting doors operate via track rollers.
Track Roller: Roller assembly for guiding the door sections along track.
Trajectory: The arc of travel or sweep of the top section as the door is raised from closed to open position.
Turn: A 360-degree revolution of a component about its axis.
Upper Vertical Track: Upper track assembly on a vertical lift door.
Vertical Lift: Refers to a hardware design that causes doors to open vertically where no horizontal tracks or required.
Vertical Lift Drum: A cable drum with changing radium grooves to negate spring tension.
Vertical Track: The portion of a track that is orientated vertically and is adjacent to the jamb.
Weather-strip: Material used at the perimeter of an overhead door, or between joints of an overhead door, intended to improve a door’s performance against air infiltration and thermal transmission.
Winding Cone: Part that fits into a torsion spring permitting winding and tension adjustment.
Winding Rod: A solid rod that fits into the socket of the winding plug to tension torsion springs.
Wire Size: The diameter of the wire in a spring.