Why Are Office Chairs Designed with Five-star Bases?

2022-03-11 14:43:53 admin

Office chairs currently on the market are basically with a five-star base.

But why not three-star feet or four-star feet? The three-star and four-star feet should also be stable and cost-saving. It is impossible that the manufacturers never consider this this kind of scheme. So why do manufacturers still choose the five-star base design?

We should consider the following points for the design of swivel chair legs: cost, stability, and less space occupied.

The cost naturally depends on the number of feet.

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(Red is the chair foot, black is the base tip connecting line)

Stability does not depend on the center point to the tip, but the length of the vertical line from the center point to the connecting line of the adjacent tips (blue line). The larger the distance, the more stable. At the same distance, the four-star feet are longer than five-star one, which means more space will be taken up by the four-star feet.

Simply put, it is the inscribed circle (green line) of the polygon (black line) connecting the tips that determines the stability. The circumscribed circle (orange line) determines the area occupied. The difference in area between the two circles is the wasted part. Naturally, the less wasted, the better.

The three feet have too much difference between the two circles. When the stability is ensured, the three feet will be very long, far beyond the range of the chair cushion. Besides, the movement of the chair will easily collide with the surrounding furniture and hinder people’s activities.

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After drawing the previous conclusion, the latter is obvious. The more the number of chair feet, the closer the polygon is to the inscribed circle, and the smaller the area difference between the two circles. So five-star bases are better than the four feet one, and six feet are better than five feet.

But on the other hand, too many feet naturally increase the cost. And as there are more feet, the reduction in the area difference between the two circles becomes less and less obvious. So in general, the five-star base is the optimal solution of the compromise of stability, land occupation, and cost.

In fact, the number of chair feet also affects the comfort of people sitting on office chairs. Don’t you think putting your two feet on the five feet of office chair is very comfortable ? Moreover considering the tilt mechanism constructive, like the knee tilt mechanism, the chair will be very stable.

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