FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
Vehicle Door And Method Of Manufacturing Thereof
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
S.S. Lingras & A.P Singh
Both Indian Nationals
of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification describes the invention


Field of invention
This invention relates to method of joining sheet metal panels and more particularly it is related to joining inner and outer panels of a vehicle door.
Background art/ prior art
Vehicle door is made of two parts commonly known as inner and outer panel. Inner part it holds window glass, door trims, latches etc. and outer panel is to cover the inner panel and door mounted parts. It also gives aesthetic appearance for the vehicle. The space between the two panels used for mounting the glass and other door fitted items. Usually the panels are made of sheet metal and joined together at the outer edge. The panels are joined by single fold hemming of outer panel on the inner one. During service conditions, single fold hemming has the tendency to be opened failure of the door shell. To avoid such failure of the door shell, tag welding is provided along the hemmed edge. The welding of the panels creates problems like burning of the panels, weld spatters etc. and it is always advantages to avoid such welding of thin sheet metal panels.
Summery of the invention
The object of the present invention is to avoid welding of the sheet metal panels after hemming process.
Another object of the present invention is to provide a method of hemming the panels without any slip
Brief description of the drawings
Figure 1 shows isometric view of the door panel Figure 2 shows the enlarged view of door panel


Figure 3 shows the edges of inner and outer panels of the door before hemming Figure 4 shows the edges of inner and outer panels of the door after hemming.
Detailed description of the invention
Referring to the figures the inner (2) and outer (1) panels joined together by the process of hemming. The inner panel edge (2') is provided with a projection (3) at specific locations. A suitable adhesive is applied on the inner side of the outer panel. The outer panel edges (1') is folded and pressed by keeping the inner panel edges (2') inside. While pressing, the edges of the outer panel get folded and the projections on the inner panel depressed. The outer and inner panel bonded together by suitable adhesive and due to the projection on the inner panel gives a better holding of the inner panel by outer panel.