Multiple-axis hinge mechanism and foldable device having same

A foldable device comprising:

• a first housing;
• a second housing;
• a foldable display coupled to the first housing and the second housing;
• and a hinge mechanism coupled to the first housing and the second housing, the hinge mechanism located at a position corresponding to a bendable section of the foldable display, wherein the hinge mechanism comprises:
• an outer cover;
• at least one gear module, including:
• a first link configured to be coupled to the first housing, wherein the first link is configured to rotate about a first axis of rotation;
• a second link configured to be coupled to the second housing, wherein the second link is configured to rotate about a third axis of rotation;
• a central synchronizing gear in meshed engagement between the first link and the second link, wherein the first link and the second link each include:
• a body;
• a gear at a first end portion of the body, in meshed engagement with the central synchronizing gear;
• and
• a coupling portion at a second end portion of the body, including at least one slot configured to slidably receive a slide pin, wherein the central synchronizing gear includes:
• a body;
• a first gear at a first end portion of the body, in meshed engagement with the first link;
• and
• a second gear at a second end portion of the body, in meshed engagement with the second link;
• a first synchronizing member coupled to the first link, wherein the first synchronizing member is configured to rotate about a second axis of rotation;
• a second synchronizing member coupled to the second link, wherein the second synchronizing member is in meshed engagement with the first synchronizing member, and wherein the second synchronizing member is configured to rotate about a fourth axis of rotation;
• and
• at least one bracket coupling the at least one gear module to the outer cover;
• and
• at least one lock module for selectively locking a position of the hinge mechanism, the at least one lock module coupled to the at least one gear module
• wherein the first link and the second link, and the first synchronizing member and the second synchronizing member, are configured to rotate symmetrically about a central axis of the at least one gear module in response to an external force applied to the hinge mechanism,
• wherein the slide pin is configured to couple the at least one lock module to the at least one gear module, the slide pin moveable within a slot of the lock module, wherein the at least one lock module comprises:
• a first plate and a second plate;
• a first recess and a second recess defined in the first plate;
• a cam coupled to the second plate, the cam configured to move along the first plate, between the first recess and the second recess due to relative movement between the first and second plates as the slide pin moves within the slot of the lock module, in response to an external force applied to the hinge mechanism;
• and
• a biasing member that selectively biases the cam toward the first recess or the second recess.