, Description:FIELD OF INVENTION

The present invention relates to a profile bending fixture, configured to form the full capsule shape coaming / flange in one piece. More particularly, the present invention relates not only to simplify the bending and fit-up work of coaming but also to make whole process independent of 1000 ton hydraulic press so that forced idleness is avoided.

BACKGROUND ART

Traditionally, the coaming or flanges around lighting holes are bend in two halves using 1000 ton hydraulic press. In this technique a group of four flange joined together with tack welding and bend at once as shown in the Figure -6.

It is evident that the above process is
1. Very slow due to many redundant steps such as joining of flat bars with tack welding, marking, material handling to and fro hydraulic press, separation of individual halve flanges by gas cutting and finally grinding of burr to get smooth surface.
2. Inferior in quality and low productivity
3. Dependent on 1000 ton hydraulic press.
4. Higher matching time for two halves joining as shown in the Figure -7.

OBJECT OF INVENTION

It is the primary object of the present invention is to provide a process of execution of bending of capsule/ stadium shape coaming in one piece using profile bending fixture.
As per another object, the process for construction of profile bending fixture includes holding down arrangements of bend coaming.
As per yet another object, the process for construction of profile bending fixture also includes hand operated lever fitted with sleeve at the tip and bearing at a distance equal to the outer diameter of coaming to be shaped.
Further object includes the process of execution of bending of capsule/ stadium shape coaming in one piece using profile bending fixture with arrangement to lock the curvature of the coaming using square bar.

Therefore the aforesaid object(s) of present invention are not only to simplify the bending and fit-up work of coaming but also to make whole process independent of 1000 ton hydraulic press so that forced idleness is avoided. In addition to above the object also include improvement of quality and productivity of work by using improved technique of bending.

SUMMARY OF INVENTION

The lighting holes in hull panels are provided with coaming/ flange of suitable size. As the lighting hole is stadium/ capsule shape, therefore the coaming plates are formed in two halves either through manually bending or using hydraulic press. The two halves is then fitted around the opening resulting in 02 in Nos. butt joints.

With this invention, we will be able to form full capsule shape coaming in one piece thereby reducing no. of joint and man-hour consumption.

At first level platform is prepared at a height of 1200 mm and the Capsule/ Stadium Shape is marked on it. The two semi-circular plates are then suitably mounted over the Flat bed as per marking and then Center bolts are fitted on it. The lever is then inserted into the center bolt in such a manner that it can roll around the periphery of semi-circular plates. The whole arrangement can be seen in the attached photograph

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Fig. 1 &2 illustrates the type of lighting holes in the hull panels;
Fig. 3 illustrates how the coaming is bend in two halves with existing method;
Fig. 4 illustrates the capsule shape coaming in one piece using the fixture in accordance with the present invention;
Fig. 5 illustrates the details of profile/ flange bending fixture in accordance with the present invention;
Fig. 6 illustrates how the flanges are bend in group using existing method (prior art);
Fig. 7 illustrates how the two halves of bend coaming are fit around the lighting-hole Fig. 8, 9, 10, 11 illustrates the steps for bending capsule shape using the profile bending fixture in accordance with the present invention;
Fig. 12, 13, 14 illustrates fit-up of single pieces capsule shape coaming with the hull panels.

DETAILED DESCRIPTION WITH ACCOMPANYING DRAWINGS

During sub-assemblies of hull panels in shop, we need to do thousands of lighting- hole coaming bending and fit-up work. Traditionally the bending of coaming are carried out in two halves before fit-up of same around the holes. The problem with existing method is that it involves many redundant steps which ultimately cause delay of work and sometime idling of man-power. Owing to its dependability on 1000 Ton hydraulic press, the existing way of bending and fit-up of coaming got affected during unavailability of machine for this work. This again results in idling of man-power and stoppage of work.

The lighting holes are cut in hull panels to provide access to the tank space and reduce the weight also. Example of lighting holes are shown in the Fig 1 & 2.

It is evident from Figure 1 - 3 that the shapes of lighting holes are like Capsule or Stadium. Now to fit flanges around the hole, profiles are shaped in two pieces as shown in the Fig-3.

Traditionally, the coaming or flange around lighting holes are made in two halves either through manual hammering or by hydraulic press. When Hydraulic press is used for bending of flange, a group of four flange joined together with tack welding and bend at once as shown in the picture-6.

With present invention of profile bending fixture, we can form the full capsule shape coaming / flange in one piece as shown in the Fig 4.
The details of profile bending fixture is shown in the Fig -5
1. Semi-circular plates of thickness 60 mm and radius equal to inner diameter of coaming to be shaped (in present case 225 mm) -Qty: 02nos.
2. A lever fitted with sleeve at the tip and bearing at a distance equal to the outer diameter of coaming to be shaped.
3. Center Bolts of length 150 mm - Qty02 nos.
4. Detachable U-clamp- Qty 01 no
5. L-clamp –Qty7 nos.
6. Steel wedges- Qty 08 nos.
It is evident that 04 flat bars are bend in group. The problem with this technique is that the productivity is very low as no of steps are more like joining of flat bar, marking for bending, material handling to reach to hydraulic press, after bending is over again material handling to reach site of work, separation of individual halve flanges by gas cutting and finally grinding of burr to get smooth surface. Due to all these additional activities, the overall productivity is very low. Also when we fit the coaming/ flanges in two pieces the overall fit-up time is also very high as alignment of two separate piece will take time as shown in the picture-7.
During welding operation, two butt joint need to be welded which take time. Therefore with the existing method the overall productivity of lighting holes coaming fabrication is very low.
With this invention, we will be able to form full capsule shape coaming in one piece thereby reducing no. of joint and overall man-hour reduced due to elimination of works like joining of flat bar, marking for bending, material handling to reach to hydraulic press, after bending is over again material handling to reach site of work, separation of individual halve flanges by gas cutting, grinding of burr to get smooth surface etc.

Now let us describe the working principle of newly developed fixture.
1. At first level platform is prepared at a height of 1200 mm and the Capsule/ Stadium Shape is marked on it.
2. The two semi-circular plates are then suitably mounted over the Flat bed as per marking and then Centre bolts are fitted on it.
3. The lever is then inserted into the centre bolt in such a manner that it can roll around the periphery of semi-circular plates.
4. The whole arrangement can be seen in the attached photograph.

The newly developed profile bending fixture is a very simple tools consists of following parts as shown in Fig 5.

1. Semi-circular plates of thickness 60 mm and radius equal to inner diameter of coaming to be shaped (in present case 225 mm)-----Qty: 02 nos.
2. A lever fitted with sleeve at the tip and bearing at a distance equal to the outer diameter of coaming to be shaped.
3. Center Bolts of length 150 mm 02 nos.
4. Detachable U-clamp 01 no
5. L-clamp 07 nos.
6. Steel wedges 08 nos.

Steps in bending
1. Flat bar secured and lever is inserted in the first center bolt and bending in progress with bearing mounted on lever rolling over flat bar as shown in Fig 8.
2. Half of capsule shape bending completed and lever removed from first center bolt as shown in Fig 9.
3. Bending of other half capsule shape in-progress with lever mounted in the second center bolt as shown in Fig 10.
4. Bending of full capsule shape completed. The edges are then joined after cutting green materials as shown in Fig 11.

The fig 12, 13 and 14 shows the final design of profile bending fixture with all its details for holding down arrangements of bend coaming ,hand operated lever fitted with sleeve at the tip and bearing at a distance equal to the outer diameter of coaming to be shaped and arrangement to lock the curvature of the coaming using square bar.

ADVANTAGES AND INDUSTRIAL APPLICATION OF INVENTION
The concept, design and method of bending of capsule shape coaming in one piece using specially designed fixture is a quantum leap in the said work resulting in simplification work & huge saving in Man-days. Material hand ling time brought to zero, Burr grinding time is also zero, tack welding time become zero, reduction in coaming fit-up time is 60 %, Reduction in coaming bending time is 60 %, Reduction in welding time is 50%. The present invention has a wide range of Industrial application both for naval ship and merchant vessel construction. This system of bending &fit-up of coaming around lighting holes in a panel will reduce the over all fabrication time and improve the quality of work. Although the foregoing description of the present invention has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration by way of examples and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. The particular embodiments and applications were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such changes, modifications, variations, and alterations should therefore be seen as being within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.

Claims:We Claim

1. A profile / flange bending fixture capable of bending stadium/ capsule shape coaming in single piece comprising of:

a level platform flatbed is prepared at a height of 1200 mm with a Capsule/ Stadium shape is marked on said flatbed;

two semi-circular plates mounted over the said flatbed as per said marking with centre bolts are fitted on said plates;

a lever configured for insertion into the said centre bolt in such a manner that it can roll around the periphery of semi-circular plates; wherein the said lever is fitted with sleeve at the tip and bearing at a distance equal to the outer diameter of coaming to be shaped.

2. The profile / flange bending fixture as claimed in claim 1, wherein the said semi-circular plates are of thickness 60 mm and radius equal to inner diameter of coaming to be shaped.

3. The profile / flange bending fixture as claimed in claim 1, wherein the said center Bolts are of length 150 mm and quantity 02 nos.

4. The profile / flange bending fixture as claimed in claim 1, wherein the said fixture further includes detachable one U-clamp, seven L-clamps and eight steel wedges configured for holding the said semicircular plates in place over said marking and withstand the force released during the process of bending.

5. A process for bending of capsule/ stadium shape coaming in one piece using profile bending fixture as claimed in claim 1, comprising the steps of :

securing a flat bar and inserting a lever in the first center bolt and thereby performing bending with bearing mounted on lever rolling over flat bar;

completing the bending of half of capsule shape and thereafter lever is removed from first center bolt;
bending the other half capsule shape in-progress with lever mounted in the second center bolt; and

completing the bending of the full capsule and thereafter joining the edges after cutting green material.