Designer and manufacturer of mechanical operators for the ventilation industry


General Specifications

There are two distinct types of mechanical operators suitable for use with industrial sidewall windows—torsion lever arm and rack and pinion. Both consist of a worm and gear power actuating a revolving horizontal pipe shaft. With either type, the power may be controlled by the following:

  1. A chain wheel with a continuous chain extending to within 2'-0" of the floor.
  2. A vertical pipe shaft with handwheel attached to the lower end approximately 4'-0" above floor.
  3. A vertical pipe shaft extending to a miter gear box controlled by a handwheel or detachable crank handle at miter gear box located approximately 4'-0" above floor.

Lever Arm

  1. Force is transmitted from horizontal shaft to ventilators by malleable iron lever arms and a steel connecting bar.
  2. Provides adequate control for short runs. The lever arm design develops more torsion stress in the horizontal shaft than that of the rack and pinion design. A finer adjustment is required to obtain tight closing of ventilators farthest removed from the power.
  3. Most economical for short runs of windows.

Rack and Pinion

  1. Force is transmitted from horizontal shaft to ventilators by a reinforced pinion set screwed to the shaft and a rack arm held in mesh with the pinion by a floating steel yoke.
  2. Provides very accurate control for any length of run within table limits. This design develops minimal torsion stress and is most efficient type of operator.
  3. Most economical for long runs of windows.

The gear ratio for the 1400 series power is 20:1. The gear ratio for the 1800 series is 30:1.

Right angle transmission gears are furnished only with machine cut steel mitre gears and enclosed in oil tight housing.

Crank or handwheel controlled miter gear boxes are available in either dust or oil enclosed types.

Chain wheel type powers are recommended for single runs only. For multiple runs, parallel lines of operators located one above the other and controlled from one station, use vertical shaft control with handwheel at mire gear box. In the latter case, use one power at each horizontal shaft.

If chain wheel control is required for multiple runs, use one right angle transmission gear box at each horizontal shaft plus one power per group. Vertical shaft is required to connect the right angle transmissions. This arrangement should only be used when building conditions make it impossible to use vertical shaft and mitre gear control.

Universal joints may be used to offset vertical shafts. Degree of offset should never exceed 35 degrees.

Horizontal shafts at right angles to each other may be controlled from a single power provided that a right angle transmission gear box is used at the junction. This arrangement should be confined to short runs. Consult Dayton.

Generally, horizontal and vertical shafts are 1-5/16" O.D. standard pipe coupled together with malleable iron or steel sleeve couplings. Standard practice is to attach the lever arms or rack arm to the hardware bracket located at the bottom of pivoted, top hinged or projected down and out ventilators. Arms are attached to the top of ventilators that are bottom hinged or projected up and in types only or where clearance for arms is restricted, such as in craneways.

All shaft hangers are roller bearing type and adjustable to compensate for variation in building construction. Hangers are located at each sash mullion and intervals not to exceed 8'-0" on centers along the walls should any occur between the extremities of the individual runs of operators.