FIELD OF INVENTION
This invention relates to an insert bolt for blow molded part. The blow molded pairt is such as a tank liner, automobile spoilers including the insert bolt integrally molded therewith.
BACKGROUND/PRIOR ART
Rear spoiler (Ri, R2) in motor vehicle is generally mounted on trunk lid/back door. For hatch back vehicle it is mounted on the back door (B) as in fig. 1 and in notch back vehicle mounting is done on trunk lid (T) as shown in fig.2.
The rear spoiler is generally manufactured by process of blow molding. In blow, molding as the height of part increases the thickness of parison decreases. As the thickness of parison decreases, the contact area of bolt with blow molding material decreases and also the pull out force of the bolt is reduced.
In such situation, in order to meet the pUll out force specification there is provision of a nut (N) fastened to stud(S) as in fig. IB constituting a bolt for increasing the contact area of bolt with the material in blow molding. Thus, standard bolts are used as insert mountings (I) in blow molded spoiler (R) as in fig. lA to meet the design specification of pull out force of bolt.
The spoiler (la) with, smaller height connected to bolt (2a) is shown in fig. 2A. Spoiler with increased height and decreased thickness is illustrated in fig. 3.

The drawback of blow molding process is that with thinner spoiler wall, l:hc pullout force can't be met and also the spoiler may fail during manufacturing.
Farther, thickness in local area can't be increased. In order to increase the thickness at local area, basic wall thickness is required to be incremented i.e. thickness of initial parison. It will lead to increase in overall weight of part. Thus, the contact area of standard bolt can't be augmented without contributing to weight of the entire part. Additional weight will add to cost which will in turn affect fuel efficiency.
Now reference may be made to the following Publications/Patents.
JP2003343S.37: An umbrella like flange is connected to the top of a screw shaft. A head is equipped with a turning operation part to which an ordinary turning tool is fitted. This is mounted on the top of the umbrella like flange through the medium of a constricted part for rupturing whose diameter is made small. The constricted part for rupturing is set to be cut at the prescribed turning torque. By doing so, when tightening the bolt to a prescribed turning torque with the ordinary turning tool, the constricted part is ruptured to cut the head of the bolt, whereby the umbrella like flange with a smooth surface is left as the substantial bolt head.
A prior art provides a rivet bolt in combination with an attachment. Said rivet: bolt comprising: a flange including a top surface and a bottom surface, a first fillet between an upper cylindrical portion and said flange; and a second fillet between a shaft having threads and said flange. An inverted frusto-conical surface extending from upper edge of said cylindrical upper portion to interior base surface of the cylindrical upper portion. Said

attachment comprising: a top surface and a bottom surface with a cylindrical bore therethrough. An inverted frusto-conical surface extends from said top surface of said attachment to said cylindrical bore through said attachment. The top surface of said flange of said rivet bolt engages said bottom surface of said attachment; and,, said upper cylindrical portion of said rivet bolt resides partially within said cylindrical bore of said attachment.
Another known art discloses a hex flange bolt, including bolt head and a bolt shank connected with each other at the rounded corners transition, wherein the bolt head is provided for the hexagonal bolt head and the bolt shank is provided with a thread. Said bolt head comprises an internal hexagon.
The present invention proposes an insert bolt for blow molded part which can provide an effective solution to the existing problems.
OBJECTS OF THE INVENTION ' .
The principal object of the present invention is to provide an insert bolt for
blow molded part which obviates shortcomings of prior art.
Another object of the present invention is to provide an insert bolt for blow molded part to increase the pullout force of bolt without increasing the weight of spoiler.
Still another object of the present invention is to provide an insert boit for blow .molded part to maintain styling.
Yet another object of the present invention is to provide an insert bolt for blow molded part which is simple in construction comparatively.

SUMMARY OF THE INVENTION
According to this invention, there is provided an insert bolt for blow molded part comprising a head integrated to a stud wherein said head includes a nut integrated with a plurality of flanges therearound so as to establish maximum surface contact with mating surface of adjacent blow molded part.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings of exemplary embodiments of invention and wherein:

Fig. 1 shows: F'^ig. lA shows: Fig. IB shows: Fig. 2 shows: Fig. 2A shows: Fig. 3 shows:
Fig. 4 shows: Fig. 5 shows:
Fig. 5A shows: Fig. 6 shows:

Conventional hatch back vehicle with rear spoiler.;
standard bolt in blow molded spoiler according to Prior art.
conventional bolt
known Notch back vehicle with rear spoiler.
Smaller height spoiler in prior art.
Spoiler with increased height and decreased thickness
available in art.
insert Bolt of present invention with Blow molded part.
Perspective view of insert bolt in accordance with present
invention.
Pull out force of bolt.
mounting of novel insert bolt on a blow molded part according to present invention.

DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
The Present invention makes a disclosure in respect of an insert bolt for blow ro.olded part. The present invention focuses on rear spoiler forming the blow molded part implemented in automobile industry without restricting scope of Lhc invention to the same as its application can be further extended to other engineering arena. The same has been devised for a blow molding process to possess maximum contact surface area with the surrounding material of parison (mating surface of blow molded part) during blow molding procedure as shown* in fig. 4 in which the insert bolt (I) establishes contact with the underlying spoiler surface (S) constituting the mating surface of blow molded part. The material (M) present in blow molded part resists the insert bolt from coming out from the spoiler.
The bolt comprises a novel head (H') and stud(S') as illustrated in fig. 5. The head (H') includes a nut (1) integrated with a plurality of Ranges (2) therearound. The nut can form any shape such as rectangular. Now reference rnay be made to fig. 4, in which said flange is having two flat parts (Pi, P2) connected by means of a curved part (P3). Thus there are two bends in each flange which comprises substantially a S-section. The flat surfaces are parallel to each other to provide the maximum pull out force of bolt. The upper flat surface (PI) should .be perpendicular to the pull out force (Fl) to offer maximum resistance to the pull out force as in fig. 5A. Provision of said curved part ismade to avoid development of stress thereby preventing its failure.
The gap between upper flat part (Pi) of flange and spoiler surface (S) Iherebeldw is devised to accommodate maximum material of parison (spoiler) thereby offering resistance to pull out force of bolt.

The top portion of the stud (3) is only provided with multitude of threads for tightening the nut which is sufficient enough to accommodate the nut. This avoids provision of additional threads therebelow (top portion) as in prior art. This leads to less processing time and also cost saving inturn and ease in assembly by helping the worker in locating the nut accurately.
Thus, the aforesaid novel insert bolt of invention ensures maximum contact area'with the adjoining blow mofderi part which can be observed from fig. 6.
The instant invention also enables to maintain sufficient height of rear spoiler at the expense of less material comparatively.
Advantageous Features
Cost effective
- Meets the pull out force of bolt
Ease in assembly and less processing time
- Reduction in number of parts as flanges are integral to nut, which leads
to reduction in overall weight and this in turn increases fuel efficiency.
Enables to maintain sufficient height of rear spoiler at the expense of less
material comparatively.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

WE CLAIM:
1. An insert bolt for blow molded part comprising a head integrated to a stud wherein said head includes a nut integrated with a plurality of flanges therearound so as to establish maximum surface contact witli mating surface of adjacent blow molded part.
2. An insert bolL fur blow molded part as claimed in claim 1, wherein said flange is having two flat parts connected by means of a curved part.
3. An insert bolt for blow molded part as claimed in claim 1 or 2, wherein said flat parts are disposed in parallel to each other to provide maximum pull out force of bolt.
4. An insert bolt for blow molded part as claimed in any of the preceding claims wherein the upper flat surface is perpendicular to pull out force to offer maxiraium resistance to the pull out force.
5. An insert bolt for blow molded part as claimed in any of the preceding claims wherein the clearance between upper flat part of flange and underlying blow molded part is such that to accommodate maximum material thereof to resist pull out force of bolt.
6. An insert bolt for blow molded part as claimed in any of the preceding claims wherein the flanges placed opposite to each other are symmetrical with respect to each other.
7. An insert bolt for blow molded part as claimed in any of the preceding claims wherein the stud, top portion of which is provided with multitude of threads for tightening said head.

8. An insert bolt for blow molded part as claimed in an}/ of the preceding claims is associated with the advantageous features such as herein described.
9. An insert bolt for blow molded part substantially as herein described with reference to the accompanying drawings.