The present invention relates to a mobile joint (1) with spring
resistance, suitable for a sitting device, comprising a first and a
second joint element (10, 20), which are pivotally connected by a shaft
(3), to allow tilting of the sitting device caused by the displacement of
the users weight, comprising a first and a second parallel plate spring
(18, 19) with first and second ends, with an intermediate blocking
element (11), wherein each plate spring (18, 19) in the first end are
connected to the first joint element (10), and in the second end are
glidingly abutting the second joint element (20), the first and second
plate spring (18, 19) each having an axis of rotation that is displaced
in relation to each other and the shaft (3).