FIELD
The present disclosure relates to the field of tow hook structures.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to
have the meaning as set forth below, except to the extent that the context in whic5 h
they are used indicate otherwise.
Minimum projected area: The term “Minimum projected area” hereinafter in the
complete specification refers to the smallest area which corresponds to the two
dimensional shape produced by projecting a three-dimensional object on to a
10 plane surface, for sustaining a maximum magnitude of forces applied on the
object.
Minimum section modulus: The term “Minimum section modulus” hereinafter in
the complete specification refers to the minimum ratio of the moment of inertia
and the distance from neutral axis to the extreme fiber of an object, required to
15 endure a maximum magnitude of forces applied on the outermost section of the
object.
BACKGROUND
Heavy farming equipment like tractors need to be towed away in case of an event
such as an accident, malfunction, loss of gas, or being stuck in mud. In order to
20 tow the tractor, a tow hook is usually utilized to safely pull the tractor without any
damage. A conventionally designed tow hook structure for tractors is either inbuilt
in the front bumper or the front axle support (part of front end chassis) or is
of the boltable/ detachable type. Tractor models of different power ratings have
different tow hooks designed to suit the application need and strength. In-built
25 tow hook designs bring in the risk of failure of main chassis components of the
tractor in case the towing load exceeds the capacity due to heavy loads on the
tractor. Further, the existing boltable/ detachable tow hook designs lack the
3
capability to adjust to different loads on the same tractor and have different design
configurations for different power rating tractor models.
Therefore, there is felt a need of a front tow hook structure that alleviates the
aforementioned drawbacks.
OBJECT5 S
Some of the objects of the present disclosure, which at least one embodiment
herein satisfies, are as follows:
An object of the present disclosure is to provide a front tow hook structure that is
easy to manufacture.
10 Another object of the present disclosure is to provide a front tow hook structure
that is cost effective.
Still another object of the present disclosure is to provide a front tow hook
structure that is easy to install and maintain.
Other objects and advantages of the present disclosure will be more apparent from
15 the following description, which is not intended to limit the scope of the present
disclosure.
SUMMARY
The present disclosure envisages a front tow hook structure for a tractor. The
structure is configured to be mounted to a front axle support assembly. The
20 structure comprises a base plate, a holding plate, a U-shaped bracket, a connector,
apertures, a pin, and bolts. The base plate defines bolting holes. The holding plate
is secured to the front axle support assembly. The holding plate defines a plurality
of fitting holes. The U-shaped bracket is defined by arms and a base. The
connector spans the base and the base plate. The apertures are defined in the arms.
25 The pin is fitted between the apertures. The bolts bolt the base plate to a first set
of fitting holes in a first operative orientation in which the pin is generally
4
perpendicular to the ground and a second set of fitting holes in a second operative
orientation in which the pin is parallel to the ground.
In one embodiment, the front tow hook structure is removably mounted to the
front axle support assembly.
In an embodiment, the connector is formed by joining two linking elements end 5 nd to
end.
In another embodiment, each of the linking elements has a C-shaped
configuration.
In yet another embodiment, the connector is designed as a solid bar.
10 In still another embodiment, the connector is designed as a hollow bar.
In another embodiment, the connector is connected to the base plate at an off
centric/centric location.
In one embodiment, the area of the U-shaped bracket satisfies the condition, A =
2(w – d)* t, where ‘w’ is width of the U-shaped bracket, ‘d’ is diameter of the
15 aperture configured on the arms and ‘t’ is the thickness of the arms of the Ushaped
bracket.
In another embodiment, the area of the connector satisfies the condition, A = 2bh,
where ‘b’ is breadth of the connector and ‘h’ is height of the connector.
In yet another embodiment, the minimum projected areas of the U-shaped bracket,
20 the connector and the base plate are designed to sustain a maximum magnitude of
the horizontal pulling forces (Fh) applied on the pin.
In still another embodiment, the minimum section moduli of the U-shaped bracket
and the connector are designed to sustain a maximum magnitude of the vertical
forces (Fv) applied on the pin.
5
In an embodiment, orientation of the front tow hook structure is interchangeable
to be in line with the variation in pulling force on the structure.
In another embodiment, the front tow hook structure is oriented to make the axis
of the apertures parallel to the operative ground.
In yet another embodiment, the front tow hook structure is oriented to make 5 the
axis of the apertures perpendicular to the operative ground.
In one embodiment, the thickness of at least one of the elements selected from a
group consisting of the base plate, the holding plate, the U-shaped bracket and the
connector is directly proportional to power rating of the tractor.
10 In another embodiment, the pin is removably connected between the apertures.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A front tow hook structure for a tractor, of the present disclosure, will now be
described with the help of the accompanying drawing, in which:
Figure 1 illustrates an isometric view of a front tow hook structure mounted to a
15 front axle support assembly of a tractor;
Figure 2A illustrates an isometric view of the front tow hook structure of Figure
1;
Figure 2B illustrates an exploded view of the front tow hook structure of Figure
2A;
20 Figure 3A illustrates the front tow hook structure mounted to a front axle support
assembly of Figure 1 in a first operative orientation;
Figure 3B illustrates the front tow hook structure mounted to a front axle support
assembly of Figure 1 in a second operative orientation;
6
Figure 4A illustrates a cross-sectional view of a U-shaped bracket of the front
tow hook structure of Figure 2A for projected area calculations;
Figure 4B illustrates a cross-sectional view of a connector of the front tow hook
structure of Figure 2A for projected area calculations; and
Figure 5 illustrates a cross-sectional view of the front tow hook structure 5 of
Figure 2A.
LIST OF REFERENCE NUMERALS
100 – Front tow hook structure
102 – Base plate
10 104 – Bolting holes
106 – Holding plate
108 – Fitting holes
110 – U-shaped bracket
112 – Arms
15 114 – Base
116 – Connector
116A, 116B – Linking elements
118 – Apertures
120 – Pin
20 122 – Bolt
DETAILED DESCRIPTION
7
A preferred embodiment of a front tow hook structure for a tractor, of the present
disclosure, is now being described in detail with reference to the Figure 1 through
Figure 3B.
Referring to the accompanying drawing, Figure 1 illustrates an isometric view of
a front tow hook structure mounted to a front axle support assembly for a trac5 tor.
Figure 2A illustrates an isometric view of the front tow hook structure of Figure 1.
Figure 2B illustrates an exploded view of the front tow hook structure of Figure
2A. Figure 3A illustrates the front tow hook structure mounted to a front axle
support assembly of Figure 1 in a first operative orientation. Figure 3B illustrates
10 the front tow hook structure mounted to a front axle support assembly of Figure 1
in a second operative orientation.
The present disclosure envisages a front tow hook structure for a tractor (herein
referred as “the front tow hook structure 100”). The front tow hook structure (100)
facilitates towing of the tractor in case of an event such as an accident,
15 malfunction, loss of gas, or getting stuck by applying pulling force on the front
tow hook structure (100). The front tow hook structure (100) is configured to be
mounted to a front axle support assembly (200) of a tractor.
In an embodiment, the front tow hook structure (100) comprises a base plate
(102), a holding plate (106), a U-shaped bracket (110), a connector (116),
20 apertures (118), a pin (120) and bolts (122). The base plate (102) defines bolting
holes (104). The holding plate (106) is secured to the front axle support assembly
(200). The holding plate (106) defines a plurality of fitting holes (108). The Ushaped
bracket (110) is defined by arms (112) and a base (114). The connector
(116) spans the base (114) and the base plate (102). The apertures (118) are
25 defined in the arms (112). The pin (120) is fitted between the apertures (118). The
bolts (122) bolt the base plate (102) to a first set of fitting holes in a first operative
orientation in which the pin (120) is generally perpendicular to the ground.
Further, the bolts (122) bolt the base plate (102) to a second set of fitting holes in
a second operative orientation in which the pin (120) is parallel to the ground.
8
In an embodiment, the front tow hook structure (100) is removably mounted to the
front axle support assembly (200).
In an embodiment, the connector (116) is formed by joining two linking elements
(116A, 116B) end to end. In another embodiment, each of the linking elements
(116A, 116B) has a C-shaped configuration. In yet another embodiment, the 5 ends
of the linking elements (116A, 116B) are joined by welding. More specifically,
the ends of the linking elements (116A, 116B) are groove welded together. In
another embodiment, the connector (116) is formed by forging or rolling.
In an embodiment, the connector (116) is a solid bar spanning the base (114) and
10 the base plate (102). In another embodiment, the connector (116) is a hollow bar
spanning the base (114) and the base plate (102). The connector (116) is joined to
the base (114) and the base plate (102) by arc welding or gas welding
In one embodiment, the connector (116) is connected to the base plate (102) at an
off centric/centric location on the base plate (102). The connector (116) is
15 connected to the base plate (102) by welding. More specifically, the connector
(116) is arc welded or gas welded to the base plate (102). The connector (116) is
connected to the U-shaped bracket (110) by welding. More specifically, the
connector (116) is arc welded or gas welded to the U-shaped bracket (110).
Referring to Figure 4A, the area of the U-shaped bracket (110) satisfies the
20 condition, A = 2(w – d) *t, where ‘w’ is width of the U-shaped bracket (110), ‘d’
is diameter of the aperture (118) configured on the arms (112) and ‘t’ is the
thickness of the arms (112) of the U-shaped bracket (110).
Referring to Figure 4B, the area of the connector (116) satisfies the condition, A =
2bh, where ‘b’ is breadth of the connector (116) and ‘h’ is height of the connector
25 (116).
Referring to Figure 5, the minimum projected areas of the U-shaped bracket
(110), the connector (116) and the base plate (102) are designed such as to sustain
9
a maximum magnitude of the horizontal pulling forces (Fh) applied on the pin
(120). Similarly, the minimum section moduli of the U-shaped bracket (110) and
the connector (116) are designed to sustain a maximum magnitude of the vertical
forces (Fv) applied on the pin (120)
In one embodiment, orientation of the front tow hook structure (5 100) is
interchangeable to be in line with the variation in pulling force on the front tow
hook structure (100).
In another embodiment, the front tow hook structure (100) is oriented to make the
axis of the apertures (118) parallel to the operative ground.
10 In another embodiment, the front tow hook structure (100) is oriented to make the
axis of the apertures (118) perpendicular to the operative ground.
The bolts (122) facilitate easy interchanging of the operative orientation of the
front tow hook structure (100) in correspondence to the larger pulling force
among the resolved forces.
15 In an embodiment, when the vertical force (Fv) is greater than the horizontal force
(Fh), the front tow hook structure (100) is bolted to the first set of fitting holes
configured on the holding plate (106) such that the direction of the orientation of
the pin (120) is parallel to the ground.
In another embodiment, when the horizontal force (Fh) is greater than the vertical
20 force (Fv), the front tow hook structure (100) is bolted to the second set of fitting
holes configured on the holding plate (106) such that the direction of the
orientation of the pin (120) is perpendicular to the ground. The interchangeability
of the operative orientation of the front tow hook structure (100) by bolting makes
the front tow hook structure (100) easy to install and maintain.
25 In an embodiment, the base plate (102) has a rectangular/square configuration
with bolting holes (104) drilled in a square pattern.
10
In an embodiment, the front tow hook structure (100) fails when pulling force
applied is around 80-95% of the force required for the failure of the bolts
connecting the front tow hook structure (100) with chassis of the tractor or chassis
components, which causes the front tow hook structure (100) to fail before the
failure of the bolts or the chassis components. Thus, the shearing of the bolts a5 nd
the resultant deformation of the chassis components is prevented.
In case, the front tow hook structure (100) fails after deforming, the front tow
hook structure (100) can be replaced by another front tow hook structure (100) by
bolting the other front tow hook structure (100) to the holding plate (106).
10 In an embodiment, the front tow hook structure (100) is designed such that the
configuration of the front tow hook structure (100) is the same for tractors of all
power ratings. The modular design of the front tow hook structure (100) is easy to
manufacture and thereby, cost-effective.
In an embodiment, thickness of at least one of the elements selected from a group
15 consisting of the base plate (102), the holding plate (106), the U-shaped bracket
(110) and the connector (116) is directly proportional to power rating of the
tractor.
In another embodiment, the pin (120) is removably connected to the apertures
(118).
20 In one embodiment, the material of the U-shaped bracket (110), the connector
(116) and the base plate (102) is selected from IS standards viz. IS: 513, 1079 or
2062.
In a working example, the front tow hook structure (100) was designed and tested
for tractors of various power ratings. Each element of the front tow hook structure
25 (100) was designed to correspond with the pulling force applied for towing the
tractors of the different power ratings. The resultant thickness (in millimeters) of
U-shaped bracket (110), the connector (116) and the base plate (102) are
11
discussed in the following TABLE 1. The findings were established by keeping
the design factors and constraints of the pin (120) as constant, and considering the
pulling forces applied in vertical and horizontal directions.
Power rating of
tractor
U-shaped bracket Connector Base plate
<20hp 8 6 6
20-35hp 8 6 6
35-50hp 12 8 6
>50hp 12 8 6
TABLE 1
From TABLE 1, it is evident that the thickness of the U-shaped bracket (5 110) is
directly proportional to the power rating of the tractor. Similarly, the thickness of
the connector (116) is directly proportional to the power rating of the tractor.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages
10 including, but not limited to, the realization of a front tow hook structure for a
tractor that:
 is easy to manufacture;
 is cost effective;
 has a universal design; and
15  is easy to install and maintain.
The foregoing disclosure has been described with reference to the accompanying
embodiments which do not limit the scope and ambit of the disclosure. The
description provided is purely by way of example and illustration.
12
The embodiments herein and the various features and advantageous details thereof
are explained with reference to the non-limiting embodiments in the following
description. Descriptions of well-known components and processing techniques
are omitted so as to not unnecessarily obscure the embodiments herein. The
examples used herein are intended merely to facilitate an understanding of way5 s
in which the embodiments herein may be practiced and to further enable those of
skill in the art to practice the embodiments herein. Accordingly, the examples
should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general
10 nature of the embodiments herein that others can, by applying current knowledge,
readily modify and/or adapt for various applications such specific embodiments
without departing from the generic concept, and, therefore, such adaptations and
modifications should and are intended to be comprehended within the meaning
and range of equivalents of the disclosed embodiments. It is to be understood that
15 the phraseology or terminology employed herein is for the purpose of description
and not of limitation. Therefore, while the embodiments herein have been
described in terms of preferred embodiments, those skilled in the art will
recognize that the embodiments herein can be practiced with modification within
the spirit and scope of the embodiments as described herein.
20 Throughout this specification the word “comprise”, or variations such as
“comprises” or “comprising”, will be understood to imply the inclusion of a stated
element, integer or step, or group of elements, integers or steps, but not the
exclusion of any other element, integer or step, or group of elements, integers or
steps.
25 The use of the expression “at least” or “at least one” suggests the use of one or
more elements or ingredients or quantities, as the use may be in the embodiment
of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has
been included in this specification is solely for the purpose of providing a context
13
for the disclosure. It is not to be taken as an admission that any or all of these
matters form a part of the prior art base or were common general knowledge in
the field relevant to the disclosure as it existed anywhere before the priority date
of this application.
The numerical values mentioned for the various physical parameters, dimension5 s
or quantities are only approximations and it is envisaged that the values
higher/lower than the numerical values assigned to the parameters, dimensions or
quantities fall within the scope of the disclosure, unless there is a statement in the
specification specific to the contrary.
10 While considerable emphasis has been placed herein on the components and
component parts of the preferred embodiments, it will be appreciated that many
embodiments can be made and that many changes can be made in the preferred
embodiments without departing from the principles of the disclosure. These and
other changes in the preferred embodiment as well as other embodiments of the
15 disclosure will be apparent to those skilled in the art from the disclosure herein,
whereby it is to be distinctly understood that the foregoing descriptive matter is to
be interpreted merely as illustrative of the disclosure and not as a limitation.

WE CLAIM:
1 A front tow hook structure (100) for a tractor, said structure (100) configured to
be mounted to a front axle support assembly (200), said front tow hook
structure (100) comprising:
 a base plate (102) defining bolting holes 5 s (104);
 a holding plate (106) secured to said front axle support assembly (200),
said holding plate (106) defining a plurality of fitting holes (108);
 a U-shaped bracket (110) defined by arms (112) and a base (114);
 a connector (116) spanning said base (114) and said base plate (102);
10  apertures (118) defined in said arms (112);
 a pin (120) fitted between said apertures (118); and
 bolts (122) for bolting said base plate (102) to a first set of fitting holes in
a first operative orientation in which said pin (120) is generally
perpendicular to the ground and a second set of fitting holes in a second
15 operative orientation in which said pin (120) is parallel to the ground.
2. The front tow hook structure (100) as claimed in claim 1, which is removably
mounted to said front axle support assembly (200).
3. The front tow hook structure (100) as claimed in claim 1, wherein said
connector (116) is formed by joining two linking elements (116A, 116B) end to
20 end.
4. The front tow hook structure (100) as claimed in claim 3, wherein each of the
linking elements (116A, 116B) has a C-shaped configuration.
5. The front tow hook structure (100) as claimed in claim 1, wherein said
connector (116) is designed as a solid bar.
6. The front tow hook structure (100) as claimed in claim 1, wherein said
connector (116) is designed as a hollow bar.
7. The front tow hook structure (100) as claimed in claim 1, wherein said
connector (116) is connected to said base plate (102) at an off centric/centric
location.
8. The front tow hook structure as claimed in claim 1, wherein the area of said Ushaped
bracket (110) satisfies the condition, A = 2(w – d)* t, where ‘w’ is
width of said U-shaped bracket (110), ‘d’ is diameter of said aperture (118)
configured on said arms (112) and ‘t’ is the thickness of said arms (112) of said
10 U-shaped bracket (110).
9. The front tow hook structure as claimed in claim 1, wherein the area of said
connector (116) satisfies the condition, A = 2bh, where ‘b’ is breadth of said
connector (116) and ‘h’ is height of said connector (116).
10. The front tow hook structure as claimed in claim 1, wherein the minimum
15 projected areas of said U-shaped bracket (110), said connector (116) and said
base plate (102) are designed to sustain a maximum magnitude of the
horizontal pulling forces (Fh) applied on said pin (120).
11. The front tow hook structure as claimed in claim 1, wherein the minimum
section moduli of said U-shaped bracket (110) and said connector (116) are
20 designed to sustain a maximum magnitude of the vertical forces (Fv) applied
on the pin (120).
12. The front tow hook structure (100) as claimed in claim 1, wherein orientation
of said front tow hook structure (100) is interchangeable to be in line with the
variation in pulling force on said front tow hook structure (100).
13. The front tow hook structure (100) as claimed in claim 1, which is oriented to
make the axis of said apertures (118) parallel to the operative ground.
14. The front tow hook structure (100) as claimed in claim 1, which is oriented to
make the axis of said apertures (118) perpendicular to the operative ground.
15. The front tow hook structure (100) as claimed in claim 1, wherein thickness of
at least one of the elements selected from a group consisting of said base plate
(102), said holding plate (106), said U-shaped bracket (110) and said connec5 tor
(116) is directly proportional to power rating of said tractor.
16. The front tow hook structure (100) as claimed in claim 1, wherein said pin
(120) is removably connected to the apertures (118).