Drop Line Pulleys
- Heavy duty steel pulleys with oil impregnated bronze bearings to insure life time self-lubrication.
Pulleys mounted on rugged 3-lag bracket.
- For a high level of performance and long life we have selected the highest quality pulleys available. Both the drop line pulleys and main line pulleys have galvanized steel side plates and zinc plated steel sheaves with oil-impregnated bronze bearings. Also, for ease of installation and system durability, we provide a rugged galvanized pulley mounting bracket for both the drop line and main line pulleys. Special pulleys are available for inside and outside exterior corners, for thruwall interior mounting of controller, for counterweight and for unique cable routing needs. All steel surfaces are zinc plated or galvanized.
- Heavy structural 1" O.D. on both top and bottom of curtain
- For smooth up and down movement of the curtain and a non-sag curtain top we have selected a heavy galvanized 1" O.D. structural tubing (about 2 1/2 times as heavy as 1/2" conduit normally used). We also use 20´ lengths rather than 10´ as normally used with conduit. This substantially reduces the number of connections and potential problems resulting from loose connections. We recommend a hem pipe at the top and the bottom of the curtain. The bottom hem pipe holds the curtain without permanently fastening to the building. This provides convenient access for maintenance and cleaning of the curtain and building, as well as fair weather overhead storage. Hem pipe splices are internal for a smooth continuous outer surface.
To properly secure the heavy 1" top hem pipe to the cable drop line, we have designed a rugged galvanized steel clamp. The design of this clamp features a simple and easy drop line cable adjustment.
- Galvanized aircraft cable on all drop lines and main lines
- For strength and durability, all the drop lines are 1/8" (7x19), flexible aircraft cable. The main lines are 3/16" aircraft cable; 1/4" available where required.
We recommend 2" x 1" 14 gauge welded wire. This galvanized product is more rigid than plastic products and is less restrictive to air flow. Tensar polygrid® is available but only recommended for gable or overshot ridge applications.
- Heavy duty manual winch or automatic controllers
- Two sizes of hand winches are available. Standard duty for curtains <600 sq. ft. Heavy duty w/autobrake for all other curtains. Two electric controllers are available.
The standard Norbco Curtain Controller operates curtain movement by winching the mainline cable around a grooved drum controlled by a thermostat and timer. This unit is widely used in poultry, hog and dairy operations.
Norbco also manufactures a heavy duty electric controller, a unit which will satisfy the most critical demands for longevity, flexibility, and quality.
- Reinforced heavy duty translucent vinyl with a high UV inhibitor formula
- Heavy Duty translucent polyethylene
Shelf Bracket System
- Galvanized shelf brackets angle up at 45°. In windy situations the bottom of the curtain can lift slightly up and away from the building. Once the pressure is relieved the curtain gently falls back to its neutral position.
- Curtain is kept in place with standard zig-zag cord. In areas with high wind conditions we recommend either 1 pipe or 2 strapping and tensioners
- These uniquely designed brackets eliminate the need for installing treated wood shelving, which often shrinks and warps over time. Wood shelves also trap moisture and bedding in the curtains. The brackets are made from 1/4" galvanized steel. The brackets are installed 3´ o.c. and provide support for the curtain as well as securing the retainer line.
Upper & Lower are Both Top Down
Single - Top Down System
Upper Curtain - Top Down
Lower Curtain - Up Only