Tray arm assembly including a joint with a two-tier friction mechanism

A joint of a tray arm assembly, comprising:

• a joint body;
• a shaft configured to rotate relative to the joint body about a longitudinal axis of the shaft;
• a slip clutch assembly, comprising:
• a clutch stack, comprising:
• a plurality of first clutch plates keyed to the shaft;
• and
• a plurality of second clutch plates keyed to the joint body;
• and
• a spring configured to selectively exert a force on the clutch stack, wherein:
• the force compresses the clutch stack causing a friction between the plurality of first clutch plates and the plurality of second clutch plates with respect to a rotation of the shaft relative to the joint body;
• a bearing positioned between the joint body and the shaft;
• a nut screwed on to an outer segment of the shaft;
• a second spring pressed by the nut against a thrust bearing;
• the thrust bearing positioned between the second spring and bearing;
• the second spring exerts force on the thrust bearing;
• the thrust bearing transfers the force to the bearing;
• and
• the force exerted on the bearing creates a second friction between the bearing and the shaft.