These security shutters are a Furnish Rolling Grilles, series 375 as manufactured by “USP” complete with curtain, hood, guides, counterbalance, and options as specified.


  • manual lift
  • chain hoist using gear reduction and hand chain
  • removable hand crank using gear reduction
  • internal or external industrial motors

Details About This Commercial Garage Door

The curtain construction for this security grilles shall be USP straight pattern with all exposed metal to be aluminum. The continuous 5/16 horizontal rods are spaced 2 inches o.c. or optional 1-1/2 inch or 1 inch spacing. Links form vertical chains of eyeletted aluminum 3/4 inch wide. The chains are positioned using E-rings on 9 inches (6 inches) (3 inches) centers. Double E-rings to be furnished at ends to prevent grille from the exiting guides. The bottom of the grille shall be provided with tubular aluminum bottom bar. The bottom bar is to house locking mechanisms.

Grille Pattern




The bottom bar is to be heavy duty 2 inches x 3 inches extruded aluminum tubular bottom bar. It is designed to minimize deflection for large openings. The upper section interlocks to the vertical links. The lower section will accept (optional) internally installed cylinder locks.

The locking for manual and crank operated grilles are to be cylinder locks mounted inside the bottom bar. The gearing within motors are to be self-locking. The motorized grilles with locks require track mounted interlocks or an H operator with a lock sensor.


The spring counterbalance is to be housed in a steel pipe of the appropriate diameter and wall thickness as to support the curtain. The deflection shall be limited to a maximum of .03 inch per foot of the door width. The springs are to consist of helical torsion types designed to meet a 25 percent load factor. The safety factor allows for safe operation, ease of use, and longer spring life. The springs are to be grease packed and anchored, using a cast iron anchor, to a cold rolled steel inner shaft. The spring tension shall be fully adjustable from outside of the end bracket plate. To ensure smooth operation end, the bracket plates shall contain sealed ball bearings to minimize wear of pipe shaft.

The end bracket plates shall consist of steel plate no less than 3/16 inch thick. The bracket plates are to house pipe shaft and counterbalance the assembly. The shaft is attached to a plate by sealed ball bearings fitted onto plate.


The guides shall consist of extruded aluminum. The guide depth shall be of a length adequate to provide for the proper curtain penetration. The brush pile inserts at the throat of the guides are to reduce noise and act as a wearing surface. Locking the channels at the guide edge prevent grille from being forced out of the guide.

The hoods shall consist of a minimum of number 24 gauge hot dipped galvanized steel with a baked on gray or bronze polyester enamel coating. The hoods are designed to protect and house counterbalance assembly. To prevent hood sag intermediate supports they shall be furnished as required.

The finish for all non-galvanized surfaces shall receive a shop coat of rust inhibiting primer. Aluminum will have natural mill, or optional clear anodized, or bronze anodized finish. Stainless steel is to have number 2b or number 4 finish. Field painting is not included in this section.

Installation is to be by USP or by an authorized dealer.

For options consult the factory.

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