Support arm for medical device support system

A method of assembling a support arm of a medical device support system, comprising:

• providing a proximal hub having at least one elongated tension member fixed to the proximal hub with a free end extending away from the proximal hub;
• providing an intermediate beam having inward facing walls defining a cavity and including parallel ribs that project into the cavity defined by the inward facing walls;
• inserting the free end of the at least one elongated tension member into and through the cavity of the intermediate beam;
• inserting the free end into a distal hub so that the intermediate beam is between the proximal hub and the distal hub;
• and,
• tightening the free end to the distal hub so that the at least one tension member is in a state of tension and the intermediate beam is in a state of compression and such that the at least one tension member is secured at opposite ends to the proximal hub and the distal hub against relative pivotal movement between the intermediate beam and the proximal hub and against relative pivotal movement between the intermediate beam and the distal hub, and further such that the at least one tension member is secured at opposite ends to the proximal hub and the distal hub to prevent axial movement of the at least one tension member relative to the proximal hub and the distal hub, the at least one tension member securing the proximal hub, the distal hub, and the intermediate beam together,
• wherein the proximal hub includes a noncircular tubular end wall and the intermediate beam includes a noncircular tubular end wall, and the noncircular tubular end wall of the proximal hub is configured to mate with the noncircular tubular end wall of the intermediate beam at a mating interface without fasteners between the noncircular tubular end wall of the proximal hub and the noncircular tubular end wall of the intermediate beam such that torsional loading is transferred from the noncircular tubular end wall of the proximal hub to the noncircular tubular end wall of the intermediate beam and vice versa.

A support arm for a medical device support system, comprising:

• a proximal hub and a distal hub;
• an intermediate beam between the proximal hub and the distal hub, the intermediate beam having inward facing walls defining a cavity and including parallel ribs that project into the cavity defined by the inward facing walls;
• and,
• at least one tension member extending through the cavity of the intermediate beam, the at least one tension member being secured at opposite ends to the proximal hub and the distal hub against relative pivotal movement between the intermediate beam and the proximal hub and against relative pivotal movement between the intermediate beam and the distal hub, wherein the at least one tension member is secured at opposite ends to the proximal hub and the distal hub to prevent axial movement of the at least one tension member relative to the proximal hub and the distal hub, the at least one tension member securing the proximal hub, the distal hub, and the intermediate beam together,
• wherein the proximal hub includes a noncircular tubular end wall and the intermediate beam includes a noncircular tubular end wall, and the noncircular tubular end wall of the proximal hub is configured to mate with the noncircular tubular end wall of the intermediate beam such that torsional loading is transferred from the noncircular tubular end wall of the proximal hub to the noncircular tubular end wall of the intermediate beam and vice versa, and
• wherein the noncircular tubular end wall of the proximal hub and the noncircular tubular end wall of the intermediate beam each include a first arced portion having a first radius and a second arced portion having a second radius, wherein the first radius is different from second radius.