Section II: CONTROLS

TM 55-1730-202-14

CONTROLS

Section II.

raise the ram. Opening the release valve allows

11. GENERAL

oil to flow from the cylinder to the reservoir,

This section describes, locates, illustrates, and

causing the ram to lower.

furnishes the operator, or crew sufficient infor-

14. RAM LOCK NUT.

mation pertaining to the various controls pro-

vided for proper operation of the tripod hydrau-

The ram lock nut (4, figure 1) is located on

lic jack.

the ram (3) at the top end of the cylinder and

ram assembly (5). It provides a means of secur-

12. AIR VENT ASSEMBLY.

ing the ram in its raised position.

The air vent assembly (1, figure 2) located in

15. RISE INDICATOR.

the top of the reservoir (3) is provided to estab-

lish a zero pressure condition in the reservoir

The rise indicator (1, figure 1) is secure to the

during operation of the pump assembly, permit-

top end of the ram with a collar and wingnut.

ting a free flow of oil. The air vent must be closed

When used in conjunction with the rise indicator

when the jack is not in use to prevent oil leak-

decalcomania on the side of the cylinder, the rise

age and contamination of the oil by dirt and

indicator shows the distances, in inches, the ram

moisture.

travels when the pump is actuated.

13. RELEASE VALVE.

16. HANDLE.

The release (6, figure 2), located at the lower

The handle (8, figure 2), which is inserted in

right side of the pump body (4) controls the

the socket (7), is actuated to give the pump

return flow of oil from the cylinder and ram as-

piston the necessary reciprocating action required

to force oil into the cylinder and raise the ram.

sembly. The release valve must be closed to

Section III. OPERATION UNDER USUAL CONDITIONS

d. Maximum Closed Height. For this height

17. GENERAL.

both sets of three leg extensions (9) are used.

Instructions in this section are published for the

The no. 2 braces (8) are swung down from their

use of personnel responsible for the operation

previous position and attached to the leg exten-

of this equipment, It is essential the operator

sions with the links (10) and to the feet with

know how to perform every operation of which

no. 3 braces (11).

the tripod hydraulic jack is capable.

19. OPERATING DETAILS.

18. SETTING UP INSTRUCTIONS.

a. Positioning. The ground surface under the

a. General. The jack may be assembled in any

jack should be level. If the ground is soft, a board

of three basic closed heights by the use of the

or plank should be placed under each foot.

leg extensions. Figure 1 shows the jack with all

The jack should be placed so a Line drawn

extensions installed. The broken lines indicate

through the center of two of the feet will be

the three possible foot assembly positions.

parallel to the fuselage of the airplane or load to

b. Minimum Closed Height. For this height the

be lifted.

cylinder and ram assembly (5, figure 1), is

b. Raising.

mounted on the three legs (6) and the three foot

CAUTION

assemblies (12) are installed directy on the bot-

Do not extend the extension screw more

tom of the legs. Six no. 1 braces (7) are used.

than 12 inches

c. Intermediate Closed Height. Refer to para-

graph 18b, with the addition of one leg exten-

(1) Turn the extension screw (2, figure 1)

out until the socket in the screw contacts the

sions. Six each of the no. 1 braces (7) and no. 2

load to be lifted.

braces (8) are used.