Oki Turns Robot Leg into Office Chair

Nov 5, 2008
Masaru Yoshida, Nikkei Electronics
The "Leopard," an office chair jointly developed by Oki Electric Industry Co Ltd and Okamura Corp. The seating surface is sharply tilted forward when it is not occupied.
The "Leopard," an office chair jointly developed by Oki Electric Industry Co Ltd and Okamura Corp. The seating surface is sharply tilted forward when it is not occupied.
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The seating surface settles down by 25° when it is occupied.
The seating surface settles down by 25° when it is occupied.
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The seat is based on the "Robot Leg" developed by Oki.
The seat is based on the "Robot Leg" developed by Oki.
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The moving part of the Leopard employs the robot leg technology.
The moving part of the Leopard employs the robot leg technology.
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Oki Electric Industry Co Ltd and Okamura Corp developed the "Leopard," a concept model of an office chair that employs robot technologies used in Oki's leg-shaped robot, "Robot Leg."

The thigh area of the Robot Leg corresponds to the seating surface of the chair. The seating surface is tilted forward when it is empty. But, when it is occupied, it significantly sinks and, at the same time, the seat back moves to the position where it fits the occupant's back, providing "seating comfort akin to being held in someone's arms," the companies said.

When the occupant stands up, the seating surface follows the movement of the occupant, helping the occupant to stand up, they said.

Oki developed the Robot Leg technology based on the muscle and bone structures of the area from thighs to the hip of a human body to realize the capability to jump and land as natural as human legs. The technology was presented at an academic conference in 2005, but this is the first time that the technology has been employed in a commercial product.

The Robot Leg is mounted with springs and driving units such as motors, and it is capable of jumping. However, the leg used in the office chair does not use a motor.

"It was possible to make a motor-driven chair, but we simplified the system for office use," Oki said.

The company repeated simulations using mathematical models of human bodies and seats to design a chair that is smoothly flexed with mechanical parts such as hydraulic cylinders and springs.

Oki and Okamura will continue the development, aiming to release the product in May 2009. Carbon fiber reinforced resin, which provides strength and light weight at the same time, is used for the seat back and the seating surface of the concept model. But the companies are considering using a different material for the commercial product in view of mass productivity and price.

In addition, they plan to prepare several models for users of various weights. The current model is intended only for occupants weighing between 55 to 60kg.