STRUCTURE OF UMBRELLA

STRUCTURE  OF UMBRELLA

 

Spin your umbrellas under the rain girls; this season is a reason to look cute with small canopies and raincoats and boys may be still shy enough to carry one; but sometimes rain is no excuse! Cool and calm colored canopies with designs that wold follow your aesthetic sense may be much interesting for you from engineering point of view.

Umbrella is a highly mechanical device as defined it is a handhold portable shade to be used in rain. Most of us carry umbrella as a tool to protect from sunlight too but actually parasols are used o this purpose. Mentioning here that both are similar in structure but the only difference is in the stuff used to make them.

History of collapsible parasols is as old as 21 A.D. invented by a Chinese named Wang Mang. Not only in China but Ancient history of Egypt, Greece and Indian subcontinent tells that this device was a part of use by people living there and predominately considered as an article for females.

Various forms are available with modifications in the general design of a collapsible umbrella that consists of a lean shaft with handle for holding at one end of it and shade on another. with wiry rods or spokes type structure for supporting  shade that is usually of fiber like material. I am going to explain the about the 'Compact Umbrella' that is small enough to fit in to your  bag; that is why also known as purse umbrella .

 Compact Umbrellas are designed in a way that these may shrink in to a smaller size for easy in portability along with lesser weight. For the purpose the two components are varied in design; these are:

1. Shaft
2. Fold-able arms

A hollow shaft with less weight is required that can vary in length i.e. gets long to the required length and then back to smaller vertical dimension when needed. Shaft consists of 4 or 5 smaller shafts having diameter slightly greater than the previous one connected to it; moving inn a way that one with smallest diameter stands near the handle. Inside the whole of the shaft is provided with a spring for extension and locking. This shaft is known as telescoping shaft. The locking mechanism for the four or five shafts connected in series is a stopping and clutch mechanism. Usually small stopping rings or shat clips are used for the purpose.

Fold-able or collapsible arms are designed in a way that it serves two purpose:

1. A substitute of longer arms or spokes for supporting canopy.
2. To provide greater radial movement for opening by small vertical movement on the main hollow shaft.

Small linkages are connected in a series manner that movement of one is initial for another i.e. relative motion. These spoke like linkages are connected via pins. The whole skeleton looks certainly like the sketch shown below.