Universal Air Tools UT8955 User Manual

Operator Instructions Important

t

Includes - Foreseen Use, Work Stations, Putting Into Service,
Operating, Dismantling, Assembly and Safety Rules

Manufacturer/Supplier Product Type

Universal Air Tool Company Limited
Unit 8
Lane End Industrial Park
High Wycombe
Bucks
HP14 3BY

Tel No Fax No

[phone] (01494) 883237

Read these instructions carefully before insta lling, operating,
servicing or repairing this tool. Keep these instructions in a safe
accessible place.

Straight Reversible
Screwdriver

Model No/Nos Serial No

UT8955

RPM

1600

Cycles Per Min

Product Nett Weight Recommended Use Of

2.42

1.1

Recommended Working
Recommended Minimum
Maximum

Perso n a l Sa fe t y E q ui pm en t
Use - Safety Glasses
Use - Safety Gloves
Use - Safety Boots
Use - Breathing Masks
Use - Ear Protectors

lbs

Balancer Or Support

Kg

Air Pressure

6.3
n/a

7.0

bar
bar
bar

No

90

n/a

100

Yes

Foreseen Use

These screwdrivers are designed for the tightening and
loosening of threaded fasteners within the range as specified by
the manufacturer. They should only be used in conjunction with
1/4" male hex shank screwdriver bits and fastener drivers.
Do not use the tool for any other purpose than that specified
without consulting the manufacturer or his authorised
representative.

Work Stations

The tool should only be used as a hand held, hand operated
tool. It is always recomme nded that th e tool is used wh en
standing on a solid floor. It can be used in other positions, but
before any such use the operator must be in a secure position
having a firm grip and footing. The operator must adopt a firm
grip sufficient to resist the torque reaction of the tool, i.e. the
tool will try to turn in the hand.
The operator must also be
aware t hat when lo osening
fasten ers, the tool can move
quite quick ly aw ay from the
fastener being undone. An al-
low anc e m us t b e m ade fo r
this rearwar d mo vement t o
avoid hand entrapment. The
operator must also make al-
lowance that if the tool does
turn in the hand, the hand is
not trapped against any rigid
object.

Recommended Hose Bore

Size - Minimum

3/8 10 30 10

Ins M/M Ft M

Noise Level

Sound Pressure Level 83.0 dB(A)

PSI

Test Method

PSI

est code PN8NTC1 and ISO Standard 3744

PSI

Vibration Level

Test Method

Tested in accordance with Pneurop

11.8

Tested in accordance with ISO

standards 8662 Parts1 & 7

Putting Into Service

Air Supply

Use a clean lubricated air supply that will give a measured air
pressure at the tool of 90 p.s.i./6.3 bar when the tool is running
with the trigger fully depressed. Use recommended hose size
and length. It is recommended that the tool is connected to the
air supply as shown in figure 1. Do not connect the tool to the
air line sys tem withou t incorporating an easy to reach a nd
operate air shut off valve. The air supply should be lubricated. It
is strongly recommended that an air filter, regulator, lubricator
(FRL) is used as shown in Figure 1 as this will supply clean ,
lubricated air at the correct pressure to the tool. Details of such
equipment can be obtained from your supplier. If such
equipment is not used then the tool should be lubricated by
shutting off the air supply to the tool, depressurising the line by
pressing the trigger on the tool. Disconnect the air line and pour

Recommended Max.

Hose Length

Metres / Sec²

Page No 1

into the intake bushing a teaspoonful (5ml) of a suitable
pneumatic motor lubricating oil preferably incorporating a rust
inhibitor. Reconnect tool to air supply and run tool slowly for a
few sec onds to allow air to circulate the oil. If tool is used
frequently lubricate on daily basis and if tool starts to slow or
lose power.
It is recommended that the air pressure at the tool whilst the
tool is running is 90 p.s.i./6.3 bar. The tool can run at lower and
higher pressures with the maximum permitted working air
pressure of 100 p.s.i./7.0 bar.

Operating

Select the correct screwdriver bit or fastener driver to suit the
screw or fastener to be tightened or loosened. Slide back the
sleeve (74) and insert appropriate drive bit.
This model has an adjustable clutch so that the torque applied
to the fastener can be adjusted to give the required tightness
within the torque range of the tool. To set the tool to give a
particular torque output, first remove the clutch housin g - left
hand thread and pull out the clutch assembly being careful not
to lose guide pin and spring (32) and (31). Hold the clutch carrier
or insert a 1/4 hex Allen key into work spindle (84) and with a
spanner rotate adjustment nut (77) until it just touches sleeve
bearing (76). T his is the clu tch set at its lowest ou tput lev el.
Reassemble the tool, try it on the joint to be fastened. If more
torque is required to place the fastener repeat the process but
rotate the adjustment nut (77) until there is a gap between it and
the sleeve bearing proceeding at approximately one turn of the
nut at a time until the correct tightness is achieved. If too high a
setting is reached rotate the adjustment nut back a part of a turn
at a time.
If the adjustm ent nut (77) is rotated too far along the clutch
spindle (84) it is possible that th e clutch will not slip and a
reaction torque against the hands will be felt. In this situation, if
the fastener is not sufficiently tightened or cannot be loosened
then the tool in adjustable clutch mode has insufficient capacity.
Select a more powerful tool. The person setting up the tool must
be aware of this torque reaction at high setting levels of the
clutch and that the tool will try to turn against the hand. All that
is required is a firm grip.
The tool, when the stall torque position has been reached, can
still be used to set or loosen fasteners, provided the operator is
aware of the need to resist the torque reaction of the tool.
Furth er adjustment of adjustin g nut (77) at th is point will not
increase the output of the tool. The only thing that will affect the
output is a change in the air supply pressure. The output can be
increased up to the use of the maximum allowed supply
pressure and decreased with a reduction in supply pressure until
the tool fails to operate.
It must also be understood that even if the clutch is set to slip it
may not do so if the supply air pressure falls below the pressure
at which the clutch was set. It is therefore strongly
recommended that a pressure control valve is used. Information
as to suitable equipment can be obtained from your supplier.
When using the tool keep the screwdriver bit pressed firmly into
the screw head to avoid cam out and screw head damage.

Dismantling & Assembly Instructions

Disconnect from air supply.
Grip the tool in a vice fitted with soft jaws on the flats at the rear
end of motor housing (1) and unscrew clutch housing (75) - left
hand thread and take out the clutch assembly being careful not
to lose guide pin (32) and guide pin spring (31). Grip the clutch
and with a sharp pointed needle tool prise out retaining ring (71)
and tak e off wash er (72), ball retain ing spring (73) and ball
retaine r (74) being careful not to lose bit retaining ball (83).
Again with a sharp pointed tool, remove a second retaining ring
(71) and pull off spacer (76). Unscrew adjusting nut (77) and pull

off spring seat (78), clutch spring (79) and thrust washer (80).
Remove from vice and tap the front end to remove 4 off balls
(81). Remove wiper (87) and then remove snap ring (85) and
separate clutch jaw (82) from work spindle (84). Remove a third
retaining ring (71) and pull off dog (86) from work spindle (22).
Unscrew lock ring (29) from motor housing (1). Grip the lock
ring and push out the internal assembly and separate bearing
(35), seal plat e (33), internal gear (18), 3 off idler gears (20)
complete with 3 off idler gear bushes (21) and work spindle
(22). Idler gear bushes may be pressed out of idler gears (20)
but do not remove 3 off idler gear pins (19) from work spindle
(22).
Grip the end of rotor (26) and pull out the complete motor
asse mbly. Remove pin (28), motor gask et (44) and take off
retainer ring (38). Grip the spacer (27) and with a non metallic
or soft metal (lead or aluminium) hammer tap the splined end of
the rotor (26) to drive it through bearing (34) and end plate (23).
Remove cylinder (24) and take out 5 off rotor blades (25) from
rotor (26). Support the rear end plate (23) and tap the rotor (26)
through the rear plate (23) and bearing (34).
Pull the sides of hanger (42) apart to remove it from its retaining
holes. Drive out roll pin (40) and remove leve r (2). Unscre w
bushing (10) complete with screen (11) and carefully prise out,
with a sharp needle pointed tool, deflector stop ring (8). Pull out
deflector (7) and prise out O-ring (9) from deflector (7). Remove
2 off screws (30) and pull off housing cap (12), muffler (41) and
housing gasket (13).
Unscrew valve screw (39) and remove O-ring (36), reverse valve
retainer (15), spring (16), plastic valve (4) and pin (3). Drive out
pin (45) to remove re verse valve bus h (6), reverse valv e (5),
spring (14) and push out valve bushing (17) if a replacement is
required.

Reassembly

Clean all components and examine for wear. Look in particular
for wear and cuts on O-rings, wear on rotor blades, gear and
clutch components.
Coat all parts with a pneumatic tool lubricating oil, one
preferably containing a ru st inhibitor and gre ase all bearin gs,
gears a nd clutch parts with a molybdenu m or lithium based
general purpose grease.
Before reassembling the motor, make sure that the faces of end
plates (23) that abut cylinder (24) are flat and free from burrs. If
necessary lap on a flat very fine grade of abrasive paper.
Reassemble in the reverse order.
When re fitting the comple te motor a sse m bly to the motor
housing (1) first make sure that the motor assembly is clamped
tightly together and that the rotor spins freely, slide the motor
assembly, with gasket into the motor housing (1) ensuring that
motor pin (28) locates in the motor assembly and in the hole in
the bottom of the main bore of motor housing (1) situated
between the two main ports.
Reset the clutch as required and/or set the correct air pressure.

Safety Rules For A Screwdriver

1) Read all the instructions before using this tool. All operators
must be fully trained in its use and aware of these safety rules.

2) Do not exceed the maximum working air pressure.

3) Use personal safety equipment.

4) Use only compressed air at the recommended conditions.

5) I f the too l appea rs to mal functio n remove f rom use
immediately and arrange for service and repair.

6) If the tool is used with a balancer or other support device
ensure that it is fixed securely.

7) Always keep hands away from the working attachment fitted
to the tool.

8) The tool is not electrically insulated. Never use the tool if there
is any chance of it coming into contact with live electricity.

9) Always when u sing the tool a dopt a firm footing and/or
position and grip the tool firmly to be able to counteract any

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