Kitagawa NPGT User manual

INSTRUCTION
MANUAL
MODEL NPGT
Thin 2-jaw Parallel Gripper
・This Instruction Manual has been prepared for intended use for
production engineers and maintenance persons who operate this
product. When the beginners use this product, be sure to receive the
guidance from skilled persons, sales agents, or us in advance.
・Before installing, using, or maintaining this product, read carefully the
safety precautions given in this manual so as to understand them
completely. If you do not heed given instructions or safety
precautions, serious human accidents, death, or physical damage
may occur.
・Store this manual with care in the specified place at hand, and reread
it as necessary for correct use of the product.
・Please contact the sales agent if you have any uncertainty or doubt
about this manual.
DANGER
MA1289YHG1
Version1.01(20200715)

1
Preface
This manual provides detailed information on the thin 2-jaw parallel gripper (model NPGT)
so that you can understand its performance and functions and use it safely and correctly.
Before using this gripper, read this manual carefully to understand how to use the gripper
correctly. Always follow the instructions and warnings given in “Important Safety
Precautions” and “Precautions for Use”. Failure to follow these precautions could result
in serious human accidents.
Terms and Symbols Used for Safety
Messages
In this manual, handling precautions that are considered especially important are classified
and displayed as shown below according to the degree of risk (seriousness of harm) that
could result. Please completely understand the meaning of these terms and follow the
instructions for safe operation.
Safety Alert Symbol
This triangle is a safety alert symbol used to alert you to potential safety hazards. To avoid
death or injuries that could occur, follow the safety messages given with this safety alert
symbol.
Failure to follow the safety precautions below will result
in death or serious injuries.
Failure to follow the safety precautions below could
result in death or serious injuries.
Failure to follow the safety precautions below may result
in minor or moderate injuries.
Indicates instructions which, if you do not heed given
instructions, could result in damage to the product or
shortened service life, or damage to peripheral
equipment.

2
Disclaimer and How to Use Instruction
Manual
This product is suitable for gripping a conveyed workpiece by being installed on the robot or
loader. The product is equipped with the jaws to grip the conveyed workpiece and they are
operated by air pressure. For any other applications, please contact us.
Kitagawa Corporation shall not be held liable for human accidents, death, damage, or loss
that occurred due to a failure to follow the safety precautions given in this manual.
This manual does not predict all potential hazards in operation, inspection, and
maintenance under all environmental conditions. There will be an infinite number of matters
that cannot or must not be done, and it is impossible for the manual to cover all of them.
Therefore, the matters, unless otherwise mentioned clearly as “can be done” or “may be
done” in this manual, should be considered as “cannot be done” or “must not be done”.
Please contact us or our agents if you have an uncertainty about safety when you try to
perform operation, inspection, or maintenance not mentioned in this manual.
Warranty and Disclaimer
The product is warranted for one year after the date of delivery.
All parts used shall be those delivered by Kitagawa Corporation. Kitagawa Corporation
shall not be held liable for human accidents, death, damage, or loss that occurred due to
the use of parts which are not genuine parts manufactured by Kitagawa. Also, the use of
parts other than Kitagawa’s genuine parts will void the warranty.

3
Contents
1. Structural Drawing and Parts List 4
1-1.Model indication
1-2.Structural drawing
1-3.Seal list
1-4.Parts list
2. Important Safety Precautions 7
3. Specifications 11
3-1.Specification table
3-2.Gripping force
4. Use 14
5. Design of Jaws 15
5-1. Designing jaws to be installed on the gripper
6. Installation 16
6-1.Installing the gripper
6-2.Installing the jaws
6-3. Connecting the air piping
6-4.Installing the switches
7. Maintenance and Checking 22
7-1.Periodic checking
7-2.Maintenance interval
7-3.Grease
7-4. Disassembly and assembly procedure
8. Troubleshooting 25
8-1.Problems and countermeasures
8-2.Contact address in case of trouble
9. Others 26
9-1.Standards and directives to which the gripper conforms
9-2.Disposal of gripper

4
1. Structural Drawing and Parts List
1-1. Model indication
The model indication is as follows:
NPGT 08 S
* For the gripper equipped with the length measuring sensor, see also the separately
provided instruction manual for it.
1-2. Structural drawing
1-3. Seal list
No.
Model
202
203
204
205
209
NPGT08
X-ring X013
X-ring X136
O-ring S55
Seal washer 6S1
-
NPGT10
X-ring X014
X-ring X146
O-ring S71
Seal washer 6S1
O-ring S11.2
Series
Size
Length measuring
sensor
NPGT
NBR seal
08
10
Nil
Not equipped
S
Equipped
Master jaw
Plunger
Body
Rear cover
Piston
Cover

5
1-4. Parts list
NPGT08
No.
Parts name
Quantity
No.
Parts name
Quantity
1
Body
1
200
Plunger fixing bolt
2
2
Rear cover
1
201
Cover fixing bolt
4
3
Plunger L（R）
1（1）
202
Shaft packing
2
4
Cover
1
203
Piston packing
1
5
Master jaw L（R）
1（1）
204
O-ring
1
6
Piston
1
205
Seal washer
2
206
Positioning bushing
4
207
Setscrew
8
208
Rear cover fixing bolt
4
204
4
5
202
201
6
203
1
3
207
206
205
200
208
2

6
NPGT10
No.
Parts name
Quantity
No.
Parts name
Quantity
1
Body
1
200
Plunger fixing bolt
2
2
Rear cover
1
201
Cover fixing bolt
4
3
Plunger L（R）
1（1）
202
Shaft packing
2
4
Cover
1
203
Piston packing
1
5
Master jaw L（R）
1（1）
204
O-ring
1
6
Piston
1
205
Seal washer
2
7
Pipe
1
206
Positioning bushing
4
207
Setscrew
8
208
Rear cover fixing bolt
4
209
O-ring
1
204
2
6
205
200
4
5
202
201
203
1
3
207
206
7
209
208

7
2. Important Safety Precautions
Important safety precautions that particularly you should know or follow are summarized
below. Please read them before starting to use the product.
DANGER
Failure to follow the safety precautions below will result
in death or serious injuries.
Be sure to turn off the main power supply when installing, checking,
oiling, or replacing the gripper.
Also, shut down the air pressure in the work area.
●During work, the robot or gripper
could move abruptly and collide
with your body.
●After shutting down the air
pressure, release the air
pressure remaining inside the
gripper.
When installing, checking, oiling, or replacing the gripper, post a sign or
notice, or provide a fence, and so on to notify people around the machine
that work is in progress.
●Notify people around the machine that work is in progress and take measures to keep
people other than the operator out of the work area.
Machine motion not predicted by a third party could cause serious danger.
Take safety measures so that the operator is not injured even if the
conveyed workpiece flies out due to the reduced air pressure.
●Observe the legal safety
standards defined by each
country, such as installation of
safeguards or fall prevention
covers.
！
Main power
OFF
Air pressure
Close

8
DANGER
Failure to follow the safety precautions below will result
in death or serious injuries.
Do not modify the gripper.
●Not only the gripper is damaged
but also the gripper and fixed
workpiece may fly out.
If using the gripper as a workpiece fixture when the workpiece is drilled,
deburred, welded, or modified additionally, confirm the specifications.
●If the gripper is used out of the
specifications, not only the
gripper is damaged but also the
fixed workpiece may fly out.
Be sure to tighten the bolts with the specified torque.
●Lack of bolt quantity or tightening
torque, or excessive torque could
damage the bolt, causing the
gripper or conveyed workpiece to
fly out.
●When tightening the bolts, fix the
gripper so that it will not rotate.
Failure to do so may result in
injury by slipping your hands
when tightening the bolts.
Other than plunger fixing bolt Plunger fixing bolt
Bolt
size
Tightening
torque
Bolt
size
Tightening
torque
M3
1.0
N･m
M5
6.8
N･m
M4
2.0
N･m
M6
12.7
N･m
M5
4.5
N･m
M8
33.3
N･m
M6
7.65
N･m
M8
18.0
N･m

9
DANGER
Failure to follow the safety precautions below will result
in death or serious injuries.
Use the gripper in accordance with the legal safety standards.
●Use the gripper in accordance
with the legal safety standards
defined by each country, such as
installation of safeguards or
safety covers.

10
WARNING
Failure to follow the safety precautions below will
result in death or serious injuries.
Do not operate the machine after drinking alcohol or taking medicine.
●Impaired judgment or operation mistake
may cause serious hazards.
Do not wear clothing or accessories such as a necktie, necklace, etc.
which are easy to be caught in.
●You may be caught in the gripper.
Use the gripper within the range of specification values.
●When selecting a gripper, select the
model by referring to "Model selection"
in page 11.
●Have the gripper grip the conveyed
workpiece at the position of its center of
gravity.
●If not, not only the gripper is damaged
but also the conveyed workpiece may
fly out.
Alcohol
Medicine

11
3. Specifications
3-1. Specification table
(Standard gripping force)
Model
NPGT
08（S）
10（S）
Fluid used
Air pressure
Operating air pressure
(MPa)
0.2～0.8
Ambient temperature
range
(℃)
5～60
Jaw stroke in diameter
(mm)
16.6
20.8
Cylinder internal volume
(reciprocation)
(cm3)
31.5
60.1
Repeatability
(mm)
±0.008
Body Mass
(kg)
0.79
1.25
Ambient humidity range
(%)
30～95
Storage temperature
range
(℃)
-10～60
Noise level
(dB)
79
*Noise level is measured at a distance of 1m from the gripper in front, rear, left, and right
four positions of the gripper.

12
3-2. Gripping force
①Standard for selecting a model
Perform the following calculation and select the model that provides a gripping force
exceeding the calculation result, though a gripping force varies depending on the
shapes of jaws created by the customer and conveyed workpiece or the friction
coefficient.
F=m（g+a）/μ
(Example) When mass of conveyed workpiece = 8 kg, friction coefficient = 0.1,
and robot acceleration = 10m/s2:
F=8（9.8+10）/0.1＝1584（N）
②Gripping force
●External gripping ●Internal gripping
Ｌ：Distance up to a grip point(mm)
●Expression of gripping force
A gripping force F shown in graph
is actually measured gripping
force per jaw F1 x the number of
jaws.
(F=F1×2)
Ａ＝Ｂ
Ａ＝Ｂ
Conveyed workpiece
Conveyed
workpiece
F = Gripping force (N)
m = Mass of conveyed workpiece (kg)
g = Gravitational acceleration (m/s2)
a = Acceleration of robot/loader (m/s2)
μ = Friction coefficient of gripping part
External gripping
Internal gripping
F1
F1

13
0
100
200
300
400
500
600
700
800
900
010 20 30 40 50 60 70 80 90 100 110 120
把持力 F(N)
把持点までの距離 L(mm)
0
200
400
600
800
1000
1200
1400
1600
010 20 30 40 50 60 70 80 90 100 110 120 130 140
把持力 F(N)
把持点までの距離 L(mm)
●Determine the distance up to a grip point L as short as possible when designing
the jaws. Also, the distance up to a grip point L should be used within a range
shown in graph. If it is used out of the range, not only the specified gripping
force may not be obtained but also the wear of sliding parts may be increased.
■NPGT08（S）
■NPGT10（S）
Distance up to grip point L (mm)
Distance up to grip point L (mm)
Gripping force F (N)
Gripping force F (N)

14
4. Use
This product supplies pneumatic pressure to the unit to move the jaws in the open or
close direction for gripping the conveyed workpiece and transfers the conveyed
workpiece up to any location. After transfer, the jaws are moved in the close or open
direction for removing the conveyed workpiece.
●Do not modify the gripper. Using the modified product could cause unexpected
accidents. Kitagawa shall not be held liable for human accidents, death,
damage, or loss that occurred due to the modification.
●If using the gripper as a workpiece fixture when the workpiece is drilled,
deburred, welded, or modified additionally, confirm the specifications. If the
gripper is used out of the specifications, not only the gripper is damaged but
also the fixed workpiece may fly out.
●Wear appropriate clothing suitable for the work and wear gloves, safety
glasses, safety shoes, and helmet.
・Wearing inappropriate clothing causes the clothing to be stuck,
resulting in danger.
・Appropriate clothing will be preventive measures to prevent hazards
due to the carelessness or unexpected accidents during work.
●Do not use the product in the environment of corrosive chemicals, corrosive
gas, dust, and vibration, avoiding high temperature or direct sunlight.
●* When storing the product, apply antirust treatment and then store it in a place
free from water leakage, dew condensation, or freeze.

15
5. Design of Jaws
5-1. Designing jaws to be installed on the gripper
When designing jaws to be installed on the gripper, form the installation face to the
master jaw as shown below.
Model
A
B
C
D
E
F
G
H
NPGT 08
29.5
13.5
6.75
16
6.5
φ8
8.5
10
NPGT 10
32.5
18.5
9.25
20
6.5
φ10
20
12
Model
J
K
L
Mounting bolt size
NPGT 08
1.5
4.5
3.5
M5
NPGT 10
2
6
4.5
M6
Jaw fixing bolt
（To be prepared by
the customer）
Jaw
（To be prepared by
the customer）
Positioning bushing
Master jaw
Master jaw
Jaw
installation
face

16
6. Installation
6-1. Installing the gripper
①Front face installation
Install the gripper body using the
four fixing bolt holes and two
positioning pin holes.
The gripper fixing adapter, gripper
fixing bolts,
and positioning pins are to be
prepared by the customer.
Model
NPGT
08
10
Gripper fixing bolt size
M4
M5
Positioning
pin hole
Diameter
(0+0.025）
(mm)
φ5
φ6
Depth
(mm)
8
10
②Rear face installation
Install the gripper body using the
four fixing bolt holes and two
positioning pin holes.
The gripper fixing adapter, gripper
fixing bolts, and positioning pins
are to be prepared by the
customer.
Model
NPGT
08
10
Gripper
fixing bolt
Size
M5
M6
Thread depth
(mm)
10
12
Positioning
pin hole
Diameter
(0+0.025）
(mm)
φ5
φ6
Depth
(mm)
8
10
Gripper fixing adapter
（To be prepared by the customer）
Positioning pin
（To be prepared by the
customer）
Gripper fixing bolt
（To be prepared by the
customer）
Gripper fixing adapter
（To be prepared by the
customer）
Positioning pin
（To be prepared by the
customer）
Fixing bolt
（To be prepared by the customer）

17
③Side face installation
Install the gripper body using the
two fixing bolt holes and two
positioning pin holes.
The gripper fixing adapter, gripper
fixing bolts, and positioning pins
are to be prepared by the
customer.
Model
NPGT
08
10
Gripper
fixing bolt
Size
M6
M8
Thread depth
(mm)
10
12
Positioning
pin hole
Diameter
(0+0.025）
(mm)
φ6
φ8
Depth
(mm)
8
10
●Be sure to tighten the bolts with the specified torque. Lack of tightening torque
or excessive torque could break the bolts, causing the gripper or conveyed
workpiece to fly out.
Gripper fixing adapter
（To be prepared by the customer）
Positioning pin
（To be prepared by the customer）
Fixing bolt
（To be prepared by the customer）

18
6-2. Installing the jaws
Install the jaws using the two
mounting bolt holes and the
supplied positioning bushings.
The jaws and jaw fixing bolts are
to be prepared by the customer.
Model
NPGT
08
10
Mounting
Bolt
Size
M5
M6
Thread
depth
A(mm)
8.5
10
Positioning
pin hole
Diameter
(H8)
B(mm)
φ8
φ10
Depth
C(mm)
1.5
2
●Be sure to tighten the bolts with the specified torque. Be sure to tighten the
bolts with the specified torque. Lack of tightening torque or excessive torque
could break the bolts, causing the jaws or conveyed workpiece to fly out.
●Before installing the jaws, disconnect the air piping.
Jaw fixing bolt
（To be prepared by the customer）
Jaw
（To be prepared by the customer）
Master jaw
Positioning bushing
Lead-in part
Positioning bushing
Attach positioning bushings with the lead-in part
facing the jaw side.