Current through Register Vol. 54, No. 38, September 21, 2024
(a)
Types. Machines shall be of the direct-connected type or shall
be driven by multiple V-belts. Cast iron gears shall not be used.
(b)
Brake. A
mechanically-applied, electrically released brake shall be applied to the motor
shaft for direct connected units or to the input shaft for belt-driven units.
The brake shall be capable of stopping and holding the manlift when the
descending side is loaded with 250 pounds on each step.
(c)
Belt. Belts shall
conform to the following:
(1)
Material. The belts shall be made of hardwoven canvas,
rubber-coated canvas, leather, or other material meeting the strength
requirements of paragraph(s) of this subsection, and having a coefficient of
friction such that when used in conjunction with an adequate tension device it
will meet the brake test specified in subsection (b).
(2)
Width. The width of
belts shall conform to the following:
| Minimum Width (in
inches) | Total Travel (in feet) |
| 12 | 0-100 |
| 14 | 100-150 |
| 16 | More than 150 |
(3)
Strength. The strength
of belts shall be not less than 1,500 pounds per inch of belt width for belts
having a distance between pulley centers not in excess of 100 feet and 1,800
pounds per inch of belt width for belts having a distance between pulley
centers of over 100 feet but in excess of 200 feet for over 200 feet, 2,450
pounds per inch of belt width.
(4)
Belt fastenings. Belts shall be fastened by a lapped splice or
shall be butt-spliced with a strap on each side of the belt as follows:
(i) For lapped splices, the overlap of the
belt at the splice shall be not less than three feet when the total travel of
the manlift does not exceed 100 feet and not less than four feet if the travel
exceeds 100 feet.
(ii) When butt
splices are used the straps shall extend not less than 3 feet on one side of
the butt for a travel not in excess of 100 feet and 4 feet for a travel in
excess of 100 feet.
(iii) For 12
inch belts, the joint shall be fastened with not less than 20 special elevator
bolts, each of a minimum diameter of 1/4 inch. Such bolts shall be arranged
symmetrically in five rows so arranged as to cover the area of the joint
effectively. Reference should be made to Exhibit B of §
7.232 (relating to exhibits-safety
diagrams).
(iv) The minimum number
of bolts for a belt width of 14 inches shall be not less than 23 and for belt
widths of 16 inches, the number of bolts shall be not less than
27.
(5)
Pulleys.
Drive pulleys and idler or boot pulleys shall have a diameter of not
less than 20 inches.
(d)
Pulley protection. The machine shall be so designed and
constructed as to catch and hold the driving pulley in the event of shaft
failure.
