Automatically actuated split-collar active mechanical brake for surgical lighting systems

An adjustable friction apparatus for use on a support structure in a surgical theatre, said friction apparatus comprising:

• a support having spindle that is symmetrical about a central axis;
• a hub moveable relative to said spindle;
• a split-collar ring disposed on said spindle having a frictional surface disposed along an inner surface of said ring for engaging an outer surface of said spindle, said ring having a gap that defines two leg sections;
• a cutout in said ring opposite to said gap that allows free ends of said leg sections to flex towards each other, said free ends of the leg sections being spaced apart from each other;
• a fastener extending through said free ends of the leg sections for releasably fastening said leg sections to said spindle, said fastener operable to releasably bias said free ends of said leg sections toward each other wherein said frictional surface applies a clamping force to said spindle;
• and,
• a surface on said hub disposed to engage a surface on one of said leg sections when said hub rotates in a first direction relative to said spindle, engagement of said surface on said one of said leg sections with said surface on said hub to cause said leg section to reduce engagement between said leg section and said spindle.

A support structure for use in a surgical theater, said support structure comprising:

• a support having a cylindrical hub that is symmetrical about a central axis;
• an arm movable relative to said hub, said arm connected to a spindle that is symmetrical to and movable about said central axis, said spindle having a cylindrical outer surface;
• a split collar disposed between said hub and said spindle, said collar having a frictional surface disposed along an inner surface thereof, said frictional surface engages the outer surface of said spindle;
• said collar having two leg sections with free ends that are able to move toward and away from each other;
• an adjustable fastening element extending through said free ends of said leg sections, said fastening element operable to clamp said collar onto said spindle, and to compress said frictional surface on said collar against said outer surface of said spindle, said fastening element including biasing means for biasing said free ends of said leg sections toward each other;
• and
• a surface on said hub disposed to engage a surface on one of said leg sections when said hub rotates in a first direction relative to said spindle, engagement of said surface on said one of said leg sections with said surface on said hub causes said leg section to reduce engagement between said leg section and said spindle.

A support structure for use in a surgical theater, said support structure comprising:

• a support having a cylindrical hub that is symmetrical about a central axis;
• an arm movable relative to said hub, said arm connected to a spindle that is symmetrical to and movable about said central axis, said spindle having a cylindrical outer surface;
• a split collar disposed between said hub and said spindle, said collar having a frictional surface disposed along an inner surface thereof, said frictional surface in engagement with the outer surface of said spindle;
• said collar having two leg sections with free ends that are able to move toward and away from each other;
• an adjustable fastening element extending through said free ends of said leg sections, said fastening element operable to clamp said collar onto said spindle, and to compress said frictional surface on said collar against said outer surface of said spindle, said fastening element including biasing means for biasing said free ends of said leg sections toward each other;
• and
• a surface on said hub disposed to engage a surface on one of said leg sections when said hub rotates in a first direction relative to said spindle, engagement of said surface on said one of said leg sections with said surface on said hub causes said leg section to reduce engagement between said leg section and said spindle.