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International Conference on Manufacturing Excellence (MANFEX 2013)
ISBN: 978-93-83083-17-6 ♦92♦
Innovative Design of Multi Jaw
Wrench and its Analysis
Dheeraj Singh
1
, Ashish Srivastava
2
, Gaurav Verma
3
, Manasi Chauhan
4
, Amit Gupta
5
1,3,4,5
Research Scholar, Mechanical Engineering
2
Associate Professor, Department of Mechanical engineering
1,2,3,4,5
Noida Institute of Engineering & Technology, Greater Noida- India
Abstract: The importance of machine industry is increasing
day by day asking for the enhancement of tool design to
manifold the efficiency. Design needs to be modified for the
tool enhancement. The “multi jaw wrench” product design
could be taken as an example. This article explores the issues of
mechanical products innovation, applies the theories of
innovation to a manual wrench and concludes with new
modifications, principles and design process. This paper
presented a proposed design of multi jaw wrench over the
conventional wrench, analysis in terms of forces, effort applied
and feasibility and also presented the comparative study of
conventional wrenches by the new proposed design. The
experimental study and the analysis have been done by using
3D modelling software Solid Works and Ansys. The obtained
result shows that the effort has been reduced to 80% and the
force and stress has been reduced to an optimum level which
tends to feasibility of the product in the market.
1. INTRODUCTION
Multi jaw wrench is an extension of a simple wrench and is
used for fastening and unfastening nuts of a car wheel
simultaneously. A wrench (or spanner) is a tool used to
provide grip and mechanical advantage in applying torque
to turn objects usually rotary fasteners, such as nuts and
bolts or keep them from turning.[1]
In British English, spanner is the standard term. The most
common shapes are called open-ended spanner and ring
spanner. The term wrench refers to various types of
adjustable spanner. In American English, wrench is the
standard term. The very most common shapes are called
open-end wrench and box-end wrench[2]. In American
English, spanner refers to a specialized wrench with a series
of pins or tabs around the circumference. (These pins or tabs
fit into the holes or notches cut into the object to be turned.)
In American commerce, such a wrench may be called a
spanner wrench to distinguish it from the British sense of
spanner.
Higher quality wrenches are typically made from
chromium-vanadium alloy tool steels and are often drop-
forged [3].
2. LITERATURE SURVEY
Wrenches have existed for many centuries, but saw a great
blossoming of development starting in the 19th century. The
first patent for a wrench was granted in 1835 to Solymon
Merrick. Meanwhile this long period, different varieties of
wrenches came into existence. Some of their description is
as follows:-
Table 2.1 Types of wrenches and their application
S.No.
Name of
wrench
Purpose and application
Figure
1. Box end
wrench
This is a one-piece wrench
with an enclosed opening that
grips the faces of the bolt or
nut. The recess is generally a
six-point or twelve-point
opening for use with nuts or
bolt heads with a hexagonal
shape. The twelve-point fits
onto the fastening at twice as
many angles, an advantage
where swing is limited. Eight-
point wrenches are also made
for square-shaped nuts and
bolt heads. Ring spanners are
often double-ended and
usually with offset [10
].
2. Open end
wrench
A one-piece wrench with a U-
shaped opening that grips two
opposite faces of the bolt or
nut. This wrench is often
double-ended, with a
different-sized opening at
each end. The ends are
generally oriented at an angle
of around 15 degrees to the
longitudinal axis of the
handle. This allows a greater
range of movement in
enclosed spaces by flipping
the wrench over [4
].
Innovative Design of Multi Jaw Wrench and its Analysis
ISBN: 978-93-83083-17-6 ♦93♦
3. Spark plug
wrench
A tube with six-sided sockets
on both ends. It is turned with
a short length of rod inserted
through two holes in the
middle of the [6
].
4. Combinatio
n wrench
A double-ended tool with one
end being like an open-end
wrench or open-ended
spanner, and the other end
being like a box-end wrench
or ring spanner. Both ends
generally fit the same size of
bolt [4
].
5. Socket
wrench
A hollow cylinder that fits
over one end of a nut or bolt
head. It may include a handle,
if it does not then it is often
just referred to as a socket
and is usually used with
various drive tools to make it
a wrench or spanner such as a
ratchet handle, a tee bar or a
knuckle bar (single axis
pivot). It generally has a six-
point, eight-point or twelve-
point recess, may be shallow
or deep, and may have a
built-in universal joint. [5
].
6. Cone
wrench
A thin open-end wrench used
to fit narrow wrench flats of
adjustable bearing bicycle
hubs. Called a "cone" wrench
because it fits wrench flats of
the cone section of a "cup and
cone" hub, this tool is also
used with some other
adjustable hub bearings. The
wrench is very thin so has
little strength; to compensate,
cone wrenches typically have
a large head. Most bicycle
front hubs use a 13 mm; most
rears use 15 mm. [8
].
7. 4-wayleg
wrench
A socket wrench used to turn
lug nuts on automobile
wheels. [4
].
On the basis of above survey there is a gap between the
design of wrenches and modern automobiles. Some of bolts
are more complicated to open and some are very time taking
process. Here in this paper a new proposed design of multi
jaw wrench is introduced for the opening of 4 bolts of any
car simultaneously.
Today, generally we are using box end
wrench and four way wrench for fastening and unfastening
the nuts of a car. But the main problem with such
combinations is that there is a requirement of large amount
of force for unfastening the nuts. Multi jaw wrench provides
a better option for fastening and unfastening the nuts by
reducing the force applied along with the time involved.
3. PROPOSED DESIGNS OF MULTI JAW WRENCH
Multi jaw wrench are designed by the combination of spur
gear, arms, lever and handle. In its design the 4 small size
gears and one large gear are set in such a combination that it
will perform like a sun and planet arrangement. Gears are
connected by the bearings and at the front end of small gear
shaft the spanners are mounted. This assembly is fitted to
the four nut and bolt arrangement of wheel. And efforts are
applied at the end of lever. At the same time four bolts are
open simultaneously. In its design the effort required is
comparatively more than the effort of single nut opening.
But the overall performance is better than the other design.
Instead of effort applied by the hand, machines like robotic
manipulators may be used to easy operation.
Fig. 3.1 Proposed design of multi-jaw wrench
In the above figure 3.1 the design of multi jaw wrench is
shown. In the operation of fastening the operation is
performed very well but there are some shortcomings in the
design these are as follows:-
In the design shown in figure 3.1, here was interference
between the bearing and the gear size.
The effort developed by the handle was not enough to
unfasten the bolt.
The rod passing through the bearing of side of gears was not
able to withstand the frame.
International Conference on Manufac
turing Excellence (MANFEX 2013)
ISBN: 978-93-83083-17-6
To overcome these short coming, a new modified design is
proposed. which
is shown in figure 3.2, 3.3,3.4,3.5.
Fig.
3.2 3D view of modified multi jaw wrench
Fig.
3.3 multi jaw wrench (front view)
Fig.
3.4 multi jaw wrench (side view)
turing Excellence (MANFEX 2013)
To overcome these short coming, a new modified design is
is shown in figure 3.2, 3.3,3.4,3.5.
3.2 3D view of modified multi jaw wrench
3.3 multi jaw wrench (front view)
3.4 multi jaw wrench (side view)
Fig.
3.5 multi jaw wrench (showing applied torque and reaction force)
3.1 Design of Spur
Gear of multi jaw wrench
The prime requirement of a gear drive is to transmit power
at a particular velocity ratio for certain working condition,
such as, operating time, nature of load, etc. The following
points must be considered while designing a gear d
1.
Highest static load acting on the gear tooth due to high
starting torque.
2.
Dynamic load at normal running conditions due to
profile error on the tooth.
3.
Wear characteristics of the tooth for increasing its life.
3.2 Force Analysis
The design of
multi jaw wrench is validated by the analysis
of forces on its gear teeth, reaction of forces and torque
applied to end of the lever.[7]
Fig.
3.6 Forces on gear teeth[7
♦94♦
3.5 multi jaw wrench (showing applied torque and reaction force)
Gear of multi jaw wrench
The prime requirement of a gear drive is to transmit power
at a particular velocity ratio for certain working condition,
such as, operating time, nature of load, etc. The following
points must be considered while designing a gear d
rive. [6
].
Highest static load acting on the gear tooth due to high
Dynamic load at normal running conditions due to
Wear characteristics of the tooth for increasing its life.
multi jaw wrench is validated by the analysis
of forces on its gear teeth, reaction of forces and torque
3.6 Forces on gear teeth[7
]
Innovative Design of Multi Jaw Wrench and its Analysis
ISBN: 978-93-83083-17-6 ♦95♦
The normal force F
n
as shown in the above Fig.3.6, acting
along the pressure line, can be resolved into two
components, tangential force F
t
and radial force F
r
. Thus,
F
t
= F
n
cosα
and F
r
= F
n
sinα = F
t
tanα
where α is the pressure angle.
F
t
is responsible for transmitting torque and hence the power
while the F
r
is called the separating force, which always
acts towards the centre of the gear.
In the force analysis of a gear drive, an assumption is made
that the tangential force remains constant in magnitude as
the contact between two teeth moves from top of the tooth
to its bottom. The torque transmitted by F
t
with respect to
the centre of the gear is
T= F
t
xd/2
Also by using the relation P = F
t
× v, the tangential force
responsible for transmitting power can be obtained, where P
is the power (kW), v is the pitch line velocity (m/s)and F
t
is
tangential force (KN).
While the analysis of the gear teeth the following
assumptions are used.
1. The tangential component, Ft, is uniformly distributed
across the face width. But practically the distribution is
non- uniform. This assumption is valid for small face
widths, i.e. 9.5m≤b≤12.5m, where m is the module of
the gear.
2. The effect of the radial component Fr, which produces
direct compressive strength, is neglected.
3. The maximum stress is assumed to occur when the
entire load is at the tip of the tooth.
4. The tooth is assumed to be a simple cantilever beam.
5. The effect of stress concentration and manufacturing
error are neglected.
4. RESULT & DISCUSSION
Design of the proposed model and their FEM results are
obtained from solid works 3D software.
There are some assumptions in the FEM analysis these are
as follows:-
1. Material should be uniform throughout.
2. No interference in meshing.
3. All joints are welded properly.
The analysis has been done for every part of the assembly of
multi jaw wrench. Table 4.1 shows the every part of the
assembly with the information required for the analysis by
Finite Element Method.
Table 4.1 Model information of assembly parts
Document Name Description
Multi jaw wrench It is used for tighting & untighting
of nut simultaneously.
Centre gear It is the centre gear of our design
which used to rotate the other gear
on their respective position
flange bolt-1 It is used to assemble the gear 1 with
fixed plate.
flange bolt-2 It is used to assemble the gear 2 with
fixed plate.
flange bolt-3 It is used to assemble the gear 3 with
fixed plate.
flange bolt-4 It is used to assemble the gear 4 with
fixed plate.
Fixed plate It is used to assemble the all 5 gear
at their respective position.
It is the major support of the design.
It is the only part which is fixed.
gear-1 They will used to transmit the
rotating force (torque) to the nut
through spanner.
gear-2 They will used to transmit the
rotating force (torque) to the nut
through spanner.
gear-3 They will used to transmit the
rotating force (torque) to the nut
through spanner.
gear-4 They will used to transmit the
rotating force (torque) to the nut
through spanner.
Table 4.2 shows the properties of the carried out studies. It
provides the information about the conditions of the
different parameters while analyse the meshing of MJW.
International Conference on Manufacturing Excellence (MANFEX 2013)
ISBN: 978-93-83083-17-6 ♦96♦
Table 4.2 study properties
Study name Fem analysis
Analysis type Static
Mesh Type: Solid Mesh
Solver type FFE Plus
In plane Effect: On
Soft Spring: Off
Inertial Relief: Off
Thermal Effect: Input Temperature
Zero strain temperature 298.000000
Units Kelvin
Include fluid pressure effects
from Solid Works Flow
Simulation
Off
Friction: On
Ignore clearance for surface
contact
On
Use Adaptive Method: On
Table 4.3 Units of parameters
Unit system: SI
Length/Displacement Mm
Temperature Kelvin
Angular velocity rad/s
Stress/Pressure N/m^2
Table 4.3 describes the units of different parameters in FEM
analysis.
Table 4.4 Specification of material for the parts
No. Body Name Material Mass Volume
1
Solid Body
1(Boss-Extrude3)
Cast Carbon
Steel
0.160463
kg
2.05722e-005
m^3
2
Solid Body
1(Fillet4)
Cast Carbon
Steel
0.056270
6 kg
7.21418e-006
m^3
3
Solid Body
1(Fillet4)
Cast Carbon
Steel
0.056270
6 kg
7.21418e-006
m^3
4
Solid Body
1(Fillet4)
Cast Carbon
Steel
0.056270
6 kg
7.21418e-006
m^3
5
Solid Body
1(Fillet4)
Cast Carbon
Steel
0.056270
6 kg
7.21418e-006
m^3
6
Solid Body
1(Fillet5)
Cast Carbon
Steel
0.150844
kg
1.9339e-005
m^3
7
Solid Body
2(<gear>-<Spline
Cut Copies>)
Cast Carbon
Steel
0.109437
kg
1.40304e-005
m^3
8
Solid Body
1(CirPattern1)
Cast Carbon
Steel
0.169402
kg
2.17182e-005
m^3
9
Solid Body
1(CirPattern1)
Cast Carbon
Steel
0.169402
kg
2.17182e-005
m^3
10
Solid Body
1(CirPattern1)
Cast Carbon
Steel
0.169402
kg
2.17182e-005
m^3
11
Solid Body
1(CirPattern1)
Cast Carbon
Steel
0.169402
kg
2.17182e-005
m^3
The above table 4.4 shows the characteristics of the
material. The material selected for the different parts of
MJW is cast carbon steel which is a ductile material. Table
indicates the mass and volume of the every part of the multi
jaw wrench.
Table 4.5 Cast carbon steel properties.
Property Name Value Units Value Type
Elastic modulus 2e+011 N/m^2 Constant
Poisson's ratio 0.32 NA Constant
Shear modulus 7.6e+010 N/m^2 Constant
Mass density 7800 kg/m^3 Constant
Tensile strength 4.8255e+008 N/m^2 Constant
Yield strength 2.4817e+008 N/m^2 Constant
Thermal expansion
coefficient
1.2e-005 /Kelvin Constant
Thermal conductivity 30 W/(m .K) Constant
Specific heat 500 J/(kg .K) Constant
Table 4.5 shows the mechanical and thermal properties of
the material cast carbon steel.
Loads and Restraints
1. We can apply maximum of 350 N of force through the
handle.
2. We can only apply load on the handle.
3. All restraints force act in opposite direction of the
applied force
Study Results
The results are carried out by the FEM Analysis of the
MJW.
(a)
Innovative Design of Multi Jaw Wrench and its Analysis
ISBN: 978-93-83083-17-6 ♦97♦
(b)
(c)
(d)
(e)
Fig.4.1 (a),(b), (c),(d),(e) Results of solid meshing of multi jaw wrench in
terms of force and stress
The above study results are indicates the satisfactory results
and design of Multi jaw wrench, all the mechanical
properties like elastic modulus, shear modulus tensile and
yield strength which are shown in table 4.5 for the material
cast carbon steel (AISI 1020 cold rolled steel).
5. CONCLUSION
The proposed design of multi jaw wrench has the
beneficiary advantages in the automobile sector especially
in wheels of heavy duty and light duty vehicles. As per the
result of this paper it can be concluded that it reduces the
time as well as the human efforts in terms of torque. Further
modifications are possible to use the multi jaw wrench in
other automobile industries and the effort can be minimized
by using the machine efforts instead of human efforts to
unfasten the bolts.
REFERENCE
[1] Department of Theoretical Mechanics Harbin Institute of
Technology. Theoretical Mechanics [M]. Beijing: Higher
Education Press, 2002.
[2] Lu Xin sheng. Zhou hong. Pneumatic automation system
optimal design. Shanghai: Shanghai Science and Technology
Literature Press, 2000.
[3] Published by Air Engineering Handbook 3. Aerodynamic
engineering handbook. Beijing: National Defence Industry
Press, 1995.
[4] S.C. & L.M. Gould (1886). The Bizarre Notes and Queries in
History, Folk-lore, Mathematics, Mysticism, Art, Science,
Etc..
[5] SMC (China) Limited ed. Modern practical pneumatic
technology. Beijing: Mechanical Industry Press, 1997.
[6] The Boston Wrench Group (Imported English coach
wrenches or 18th w19th century American copies?)".
Davistown Museum. Retrieved 2008-08-11.
[7] The Monkey Wrench' mill building at 143 Main St. in
Springfield, MA". Bemis & Call was acquired by a larger tool
company in 1939.
International Conference on Manufacturing Excellence (MANFEX 2013)
ISBN: 978-93-83083-17-6 ♦98♦
[8] William Rogers (1903, 1913). "Part 1: The Progressive
Machinist". Rogers Machinists Guide. Theo. Audel &
Company, New York.
[9] Wu Zhenshun ed. Pressure spread and control. Harbin: Harbin
Institute of Technology Press, 1995.
[10] Yang Ke zhen, Cheng Guang Yun. Mechanical Design [M].
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[11] Zhan you Gang, hong liang .Pro / ENGINEER Wildfire 2.0
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Beijing: Tsinghua University Press, 2005.
[12] Zhang Yunjie, Liu Jian, Zhou Youjun .Pro / ENGINEER
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