Operating
The output of the impact wrench in prime working condition is
governed by mainly three factors
a) the input air pressure
b) the time the impact wrench is operated on the joint. Normal time for
joints of average tension requirement 3 to 5 seconds
It is strongly recommended that an external pressure regulator ideally as
part of a filter/regulator/lubricator (FRL) is used to control air inlet
pressure so that the pressure can be set to help control the tension
required to be applied to the threaded fastener joint.
There is no consistent reliable torque adjustment on an impact wrench
of this type. However, the air inlet pressure in conjunction with the three
position regulator lever (22) can be used to adjust torque to the
approximate tightness of a known threaded joint. To set the tool to the
desired torque, select a nut or screw of known tightness of the same
size, thread pitch and thread condition as those on the job. Turn air
regulator to a set position, apply wrench to nut and gradually increase
power (by increasing air pressure) until nut moves slightly in the
direction it was originally set. The tool is now set to duplicate that
tightness, note regulator setting for future use. When tightening nuts not
requiring critical torque values, run nut up flush and then tighten an
additional one-quarter to one-half turn (slight additional turning is
necessary if gaskets are being clamped) . For additional power needed
on disassembly work, turn regulator to position 3 and increase air inlet
pressure if required. This impact wrench is rated a 1/2" bolt size. Rating
must be down graded for spring U bolts, tie bolts, long cap screws,
double depth nuts, badly rusted conditions and spring fasteners as they
absorb much of the impact power. When possible, clamp or wedge
the bolt to prevent spring back.
Soak rusted nuts in penetrating oil and break rust seal before removing
with impact wrench. If nut does not start to move in three to five
seconds use a larger size impact wrench. Do not use impact wrench
beyond rated capacity as this will drastically reduce tool life.
Note: Actual torque on a fastener is directly related to joint hardness,
tool speed, condition of socket and the time the tool is allowed to
impact.
Use the simplest possible tool-to-socket hook up. Every connection
absorbs energy and reduces power.
Dismantling & Assembly Instructions
Disconnect from air supply.
Remove oil plug (39) and drain the oil contained within the front
end of the tool into a suitable receptacle. Grip motor housing
(38) in a vice fitted with soft jaws and unscrew 4 off screws
(26) pull off clutch housing (38). Hook out oil seal (40) and
gasket (27) from clutch housing (38). Grip hammer cage (28)
and pull off the hammer mechanism assembly. Take off anvil
spacer (35) and from hammer cage (28) pull out anvil (33) with
compression spring (32) and thrust button (30). Push out 2 off
hammer pins (31) from hammer cage (28) to release 2 off
hammers (29) and carefully note how the two hammers (29)
are located to hammer cage (28) by hammer pins (31) for
reassembly. If replacements are required remove o-ring (36)
and socket retaining ring (37). Take off end cap (21) and air
regulator reverse valve assembly. Unscrew 3 cap screws (16)
and remove the rear plate (15) and pick out bearing (9). Re-
move c-ring (17) from reversing regulator (19). With a soft
hammer tap the end of rotor (14) to drive the motor assembly
out of motor housing (1). Take off cylinder (12) and take out 6
off rotor blades (13) from rotor (14). Unscrew hose adapter (6)
and remove exhaust deflector (7) and take out spring (4) and
valve stem (3).
Reassembly
Clean all components and examine for wear and cracks etc. particularly
parts of the hammer assembly, particularly anvil (33), around the area of
the square drive. Examine rotor blades for wear and o-rings and seals
for cuts and wear. Replace all parts with parts from the manufacturer or
approved supplier. Make sure the rear plate (15) that abut cylinder (12)
are flat and free from burrs. If necessary, lap faces on a flat very fine
grade of abrasive paper. Lightly coat all parts with suitable pneumatic
tool lubricating oil and reassemble in the reverse order. On completing
assembly make sure all parts are locked tight and the anvil will rotate
and the trigger and regulator reverse valve operate freely. Remove oil
plug (39) and pour into the front end 5/8 fluid oz (15cc) of standard
SAE20 grade oil. Do not overfill as this cause reduction in power. With
the throttle trigger depressed pour into the hose adapter (6) 5 ml of
suitable pneumatic tool lubricating oil and release throttle trigger.
Connect to suitable air supply and run tool slowly for 2 to 3 seconds to
allow the oil to circulate. Reset tool for operation. Refer to section -
Operating.
air supply and run tool slowly for a few seconds 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. For a lower air pressure the tool will give a lower output for
a given setting of the air regulator set for 90 psi operation and an
increased output for higher pressures. Hence it is possible that changes
in supply pressure can give situations where the fastener is under or
over tightened. For changes in pressure, the regulator position and
application should be reassessed.
It is recommended that joint tightness of the threaded fastener
assembly be checked with suitable measuring equipment.
Page No 2
Safety Rules When Using an Impact
Wrench
1) Read all the instructions before using this tool. All operators must be
fully trained in its use and aware of these safety rules. All service and
repair must be carried out by trained personnel.
2)The socket used must be of the correct drive size and the "impact"
type. Never use sockets other than impact type.
3) Do not use sockets with excessive wear to the input and output drives.
Check that the square on any other type of drive or the impact wrench is
not cracked or excessively worn before fitting or changing socket,
extension, etc. Make sure that the socket is firmly fixed to the tool.
4) Always ensure that a stable position or footing is adopted before using
the tool.
5) Ensure that the tool has been correctly set up on a test joint. Incorrect
set up could cause joint breakage with sudden and unexpected
movement of the tool.
6) Use only correct spare parts for repair.
7) Always ensure that the reverse valve is in the correct position before
operating the tool. Do not run the tool unless the socket is first located on
the joint.
8) Check hose and fittings regularly for wear. Use quick connect
couplings only as recommended. See "Putting into Service". Do not
carry the tool by the hose and ensure that the hand is away from the
on/off valve when carrying.
9) Do not attempt to hold or guide the socket by hand when the tool is
running.
10) Do not exceed maximum recommended air pressure.
11) Use safety equipment as recommended.
12) The tool is not electrically insulated. Do not use where there is a
possibility of coming into contact with live electricity.
13) Preferably shut off the air supply before changing sockets or at least
ensure that the hands are well clear of the operating trigger.
14) Take care against entanglement of moving parts of the tool with
clothing, ties, hair, cleaning rags, etc.
15) When loosening fasteners first ensure that there is sufficient
clearance behind the tool to avoid hand entrapment. The tool will move
away from the threaded joint as the nut/bolt etc. is loosened and rides up
the thread moving the tool with it.
16) Only use extensions, adaptors and universal joints suitable for use
with impact wrenches.
17) If the tool appears to malfunction remove from use immediately and
arrange for service and repair.
