TM 9-243
TYPES AND USES
Jacks are used to raise or lower work and heavy loads
short distances. Some jacks are used for pushing and
pulling operations. Others are used for spreading and
clamping operations.
SCREW JACKS
Vertical screw jacks come in several capacities and
different lowered and raised heights. The screw moves
up or down, depending on the direction the handle is
turned. These jacks are used for many different pur-
poses. They can be used to lift vehicles. They can also
be used to raise heavy crates, small buildings, or other
items too heavy to be raised by prying with wrecking
bars.
The vertical screw jack with collapsible handle is oper-
ated by hand using the collapsible handle which is
inserted in a socket.
The vertical bell base screw jack is operated by hand
using a steel bar handle which is inserted in the holes of
the top housing or head.
Another type of screw jack is called an outrigger jack. It
is equipped with end fittings which permit pulling parts
together or pushing them apart.
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