proper position and measurements for the idler are shown in
Plate XVI (p. 74).
Idlers are of two general types: Those that are mounted on a
frame bolted to a foundation and adjustable within the frame; and
those that consist of a loose pulley on a shaft whose lower end
is adjustable with reference to a floor anchor or foundation, and
whose upper end is held in place by adjustable attachments to the
frame work of the power building. If the power is properly aligned,
the former type meets all requirements, but if alignment is poor and
the features of installation abnormal, the latter type frequently
proves the more adaptable.
An ingenious way of keeping constant tension on an endless belt
used for driving a band-wheel power is to mount the idler pulley
on a truck which is movable on a track running parallel to the belt
as it leaves the engine or countershaft pulley. The idler is held
at constant tension against the belt by means of a steel cable attached
to the front end of the truck. This cable passes below the band
wheel to a point outside of the power building, where it passes under
a pulley fastened near the ground, and then over a pulley fastened
in a frame at a point 8 or 10 feet above the ground and ending in
a suspended weight that maintains the necessary tension.
Many oil companies have adopted the practice of utilizing old
steam engines by making the crank shaft and that half of the frame
to which it is attached serve as a countershaft. Sometimes a steam
engine and boilers formerly used are left in place; and the steam
engine is used as a countershaft; if the electric power or the oil or
gas engine being used fails, the drive belt is thrown off and pump-
ing is continued by steam power until the necessary repairs have
Plate X, F, shows a countershaft made from an old steam-engine
bed, as used by one of the California oil companies.
HOUSING FOR POWERS.
Plate XVIII, B and C, and XIX, A, show three standard types
of construction for power buildings used by three different oil com-
panies in three widely separated oil fields.
The power building shown in Plate XVIII, B (p. 77), is at
Bridgeport, Ill. It is sectionalized, as are all the oil-field buildings
of the company. Sections from the sides of the building can be
readily unbolted and removed in order to take out or replace old
or broken machinery. Ample light is admitted through five windows
on the long side of the building, four on the off-set side and one
at the back. The side walls are made of boards nailed to 2 by
4 inch sills and plates, with batten over the cracks. The sills are
George, H. C. Surface Machinery and Methods for Oil-Well Pumping. Washington D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc12407/. Accessed November 24, 2015.