Pulley-based adjustable strap design for virtual-reality headset

A head-wearable device, comprising:

• a display;
• a retractable side strap coupled with the display, the retractable side strap including a housing comprising:
• an anchor point;
• an adjustment mechanism configured to be adjusted to change an exposed length of the retractable side strap that is outside of the housing;
• a cable including:
• a first end coupled to a first cable-spooling portion of the adjustment mechanism,
• an intermediary portion of the cable that travels around the anchor point and is coupled with a portion of the retractable side strap, and
• a second end coupled to a second cable-spooling portion of the adjustment mechanism, wherein the intermediary portion of the cable includes a first windable segment extending from the first end of the cable and a second windable segment extending from the second end of the cable, and actuation of the adjustment mechanism results in winding or unwinding of at least a portion of each of the first windable segment and the second windable segment;
• wherein at least one of the adjustment mechanism and the anchor point maintain the cable at a predetermined tension, such that, when the adjustment mechanism is adjusted, the adjustment mechanism (i) winds the cable around the first cable-spooling portion of the adjustment mechanism or the second cable-spooling portion of the adjustment mechanism, and (ii) adjusts the exposed length of the retractable side strap to allow the head-wearable device to accommodate respective head sizes for a plurality of users of the head-wearable device.