Support arm lamp (spring arm)

Detailed application description

Description of problem:

The operating light fitting takes the form of a spring arm mounted between the cantilever mechanism and the cardan joint. It can be turned and adjusted upwards or downwards and essentially determines the height of the operating light. Like all surgical lighting components, the dimensioning of the spring arm depends on the load. A slim design plus high load carrying capacity is ideal. Despite its small diameter, the slip ring must achieve high power density. In this particular case, three load and six signal slip rings had to be accommodated in the installation space. To enable customer mounting, the slip rings moreover had to be mechanically and electrically pluggable at the interfaces to the cantilever mechanism and the cardan joint yet at the same time insensitive to mechanical stress.

Description of solution:

The LTN solution is an SA030-06/03-L01 slip ring rotary plug consisting of a plug and socket. The socket is typically installed in the spring arm and the plug in the cantilever mechanism or the cardan joint. The speed is limited to 20 rpm. The installation space for the spring arm joint is approximately 100 mm long. The 30 mm diameter is far more critical. To ensure proper mating and rotating of the contacts, the latter have a graded diameter and radial spring mounting. Silver-plated punched bending parts were chosen for the load contacts. Hard gold-plated brass rings with hard gold-plated signal springs are used for the signals. LTN load and signal rings are rated for 15 A or 2 A respectively at 48 V DC. The small size of the signal rings means any standard data format for control and video technology can be easily transmitted, e.g. CAN bus or SD video. If the plug and socket are installed in the predetermined position, the mechanical parts and electrical connection can be assembled blind.