This invention relates to fixtures for holding and bending of sheet metal
using press machine. More specifically, it relates to a fixture, which may be used
to hold, locate and bend sheet metal of various shape and size. Fixture used to
hold the sheet metal in manners that all reference surfaces given on work piece
are in proper position for the desired bending operation on the sheet metal.
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BACKGROUND OF THE INVENTION
This invention pertains to fixtures for holding and bending of the sheet
metal on press machine and more particularly to a bending tool adapted to
support and locates work to be bent. An object of this invention is the provision of
a new and improved bending fixture for press machine which is rigid, rugged,
compact, and capable of high precision holding and bending of sheet metal. This
fixture helps to minimize the setup time and maximize the productivity.
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SUMMARY OF PRESENT INVENTION
In accordance with one aspect of present invention is to provide a fixture
that facilitates holding and bending of a metal for bending operation using press
machine.
In accordance with second aspect of present invention is to provide a
fixture for bending of metal sheet for accurate positioning of workpiece on fixture.
In accordance with another aspect of present invention is to provide a
fixture for bending of metal sheet having a die and punch of desired profile.
In accordance with yet another aspect of present invention is to provide a
fixture for bending of metal sheet adapted to be fixed on the bed of press
machine.
Annexure‐II
In accordance with yet another aspect of present invention is to provide a
fixture for bending of metal sheet having top plate and base plate.
. In accordance with yet another aspect of present invention is to provide a
fixture for bending of metal sheet having a top plate assembly on two stepped
rods.
In accordance with another aspect of present invention is to provide a
lighter fixture to hold the metal sheet workpiece.
In accordance with yet another aspect of present invention is to provide a
fixture that can be properly and effectively utilized to hold position and bend
metal sheets by lesser skilled individuals.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become more apparent
and descriptive in the description when considered together with figures/flow
charts presented:
Fig. 1 is a Sectional Front view of fixture for holding Sheet metal
Fig. 2 is a Top view of Die of fixture for holding Sheet metal
DETAILED DESCRIPTION
Referring to fig. 1 & 2, present invention is a fixture 23 used to hold,
position and bend the metal sheet and adapted for use on conventional press
machine. The fixture 23 is designed to hold and bend the metal sheet 29 within
desired dimensional tolerance with respect to punch 11 and die 2 of fixture 23.
Fixture 23 for holding, positioning and bending of a metal sheet comprises
a base plate 5 having a substantially flat top surface 25 and bottom surface 8.
Base plate is made of mild steel. Die 24 having a top surface 25 in the desired
shape to be form on the metal sheet 29. Two location pins 1 are placed to hold
the sheet metal in the accurate position with respect to die 2 and punch 11. Die 2
Annexure‐II
is resting on the top surface 25 of the base plate 5. Two Allen head screw 3 are
used to align and hold the die 2 with the top surface 25 of base plate 5 through
threaded holes 27 made in base plate 5. The outer surface 7 of the small
diameter section of stepped rod 28 are fitted with base plate 5. Allen head
screws are mounted on the base plate with threads 27. Two dowel pin 4 are used
to position the punch 11 in with respect to the centre of the fixture 23.
Fixture 23 holding, positioning and bending of a metal sheet consist of the
punch 11 fitted with the top plate 13 with the help of two Allen head screw 17
fitted diagonally. The bottom surface 9 of the punch 11 is made matching the
dimensional requirement of metal sheet to be formed. Two Allen head screw 18
and two dowel pins 21 are used to align and hold the punch 11 with the bottom
surface 30 of top plate 13 through threaded holes 27 made in top plate 13.
Holding bar 20 is fitted with the top plate 13 through threaded hole. Rubber
padding 10 is provided on the punch 13 to provide cushion effect to the sheet
metal to eliminate the chance of damage. The thorough hole 21 is provided on
the punch 11 and top plate 13 for movement of the dowel pin 4. Two stepped
rods 12 are press fitted with base plate 5. The top plate 13 is guided by bushes
16 movement over stepped rod 12 mounted on the base plate 5.The outer
surface 14 of the Bushes 16 is matched with the through hole made in the top
plate 13.
Metal sheet is placed in the location pins 1. The movement of the punch
11 starts in the downward direction. The downward movement of the top plate 13
is guided by the two Stepped rods 12. The dimensional accuracy of the bending
fixture is controlled with the help of the Dowel pins 4, 21 and stepped rod 12. The
rubber pad 10 provided on the punch 11 helps the easy removal of the bended
sheet metal after operation.

WE CLAIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and is for the purpose of teaching those skilled in the art of the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications which are within the scope of the appended claims is reserved. We Claim

1. A fixture for holding, positioning and bending of a metal sheet adapted to be positioned on work table of conventional press. The fixture comprising:
- Base plate adapted to be fixed to the bed of conventional press and provides supporting surface to other sub component of fixture.
- Two stepped rods are rigidly coupled to the base plate with press fittings and guide the movement of top plate during downward stroke of punch.
- Location Pin that guide the metal sheet to remain in pre-determined position with respect to bending surface and prevent the X, Y direction movement of Sheet metal.
- Guiding dowel pins are provided to ensure positional accuracy during the downward movement of the punch.
2. The fixture for holding, positioning and bending of a metal sheet of claim 1 wherein, top and bottom surfaces of the base plate and top plate are substantially parallel.
3. The fixture for holding, positioning and bending of a metal sheet of claim 1 wherein, stepped rod is perpendicular to the top surface of the base plate.
4. The fixture for holding, positioning and bending of a metal sheet of claim 1 wherein, die in desired shape is fixed on the base plate with the help of Allen head screw and dowel pins.
5. The fixture for holding, positioning and bending of a metal sheet of claim 1 wherein, punch in desired shape is fixed on the top plate with the help of Allen head screw and dowel pins. Top plate and bottom plate is parallel with each other.
6. The fixture for holding, positioning and bending of a metal sheet of claim 1 further comprising a profiled surface on die and punch that provides the desired shape to the sheet metal during bending operation.
7. The fixture for holding, positioning and bending of a metal sheet of claim 1 further comprising a rubber padding on the punch cavity to avoid damage to metal sheet to be bend and helps easy retrieval of finished work piece. ,TagSPECI:As per Annexure-II