Spring Replacement Glossary
A-Frame Support member used to fasten torsion spring assembly of a vertical lift door to the wall above the door opening.
Adjusting Cone (Winding Sleeve, Winding Cone) Part that fits into torsion spring permitting winding and tension adjustment.
Booster Spring Additional spring provided to compensate for weakened counterbalance. (Usually extension spring.)
Cable Drums Grooved drums fitted on torsion spring shaft onto which lifting cable is wound when door is opened.
Counterweight Refers to design of door mechanisms using weights instead of springs to counterbalance door weight.
Cycle One full opening and closing operation of a sectional door.
Double Shaft Double torsion spring shaft used when additional space is required to accommodate counterbalance spring wire.
Duplex Spring A combination of two torsion springs of different diameters telescoped within common spring plugs.
Extension Springs Counterbalance springs, which provide lifting power by stretching. Generally mounted above horizontal tracks.
High Cycle Springs Special counterbalance springs with increased cycle lift capability for high usage doors.
Shaft Bearings A free rolling, cylindrical, ball bearing that is used to guide the torsion shaft, maintain alignment, and reduce friction.
Sheaves A pulley with a ball bearing built into it that is designed to handle a cable and used to control the movement of the cables employed in door counter balance system.
Side Bearing Plate (End Bearing Plate) A bracket that attaches to the horizontal supports and possibly the wall to provide a bearing surface for the torsion shaft near the ends.
Spring Assembly Hardware used to make up door counter-balance assembly.
Spring Bumper Small spring-cushioned bumper attached to horizontal track to stop door at full open position.
Spring Pad (Center Bearing Plate) Plate or bracket which is located on the wall above door opening to receive torsion spring assembly support brackets.
Spring Fittings The sleeves or cones that are used to adapt the torsion springs to the torsion shaft.
Torsion springs usually have two fittings or cones. One is a stationary sleeve or spring retainer, while the second piece is an adjusting cone or winding sleeve.
Torsion Shaft The shaft of a torsion spring assembly, which transmits lifting power of the torsion springs to cable drums and lifting cables.
Torsion Springs Counterbalance springs which provide balancing power by winding and unwinding through door cycle.
Winding Sleeve (Adjusting Cone) Part that fits into torsion springs permitting winding and tension adjustment.