LUMBER SUPPORT DEVICE

• Main Author: HATTORI TAKEMI
• Format: Patent
• Language: English
• Published: 31.01.1990
• Subjects: BEDS; CHAIRS; COFFEE MILLS; DOMESTIC ARTICLES OR APPLIANCES; FURNITURE; HUMAN NECESSITIES; PERFORMING OPERATIONS; SEATS SPECIALLY ADAPTED FOR VEHICLES; SOFAS; SPICE MILLS; SUCTION CLEANERS IN GENERAL; TRANSPORTING; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDEDFOR; VEHICLES IN GENERAL

PURPOSE:To ensure multistage setting of a stroke and to reduce a necessary control force or improve a control feeling as a given stroke is maintained by a method wherein a geneva mechanism to convert continuous rotational movement of a shaft into intermittent rotation movement of a cam is used as a drive mechanism. CONSTITUTION:When a shaft is rotated counterclockwisely by a handle, not shown, a plate 15 is also rotated simultaneously. An upper drive pin 16 on the plate 15 enters a groove 14b of a bladeform geneva gear formed in a cam 14, a lower drive pin 16' is disengaged from the bladeform geneva gear part of a cam 14, and is rotated so as to enter a groove next to a groove which the upper drive pin 16 enters. During rotation in a 180 deg. arc of a shaft, the cam 14 performs clockwise rotation, equivalent to that along the one blade of the geneva gear, through the working of the pins 16 and 16'. In this case, a maximum value of a control force exerted on a control handle is a control force = r1/r2X(a force required for rotation of the cam), wherein r1 is a distance between the drive pins 16, 16' and the center of a shaft 11 and r2 is the radius of a geneva groove part 14c. By properly selecting a ratio between r1 and r2, a control force being to be exerted on the handle can be set.