Production of surgical spectacles

• What was needed: drylin® SLW spindle linear modules
• Requirements: The machine had to guarantee a high degree of precision in angle adjustment with an accuracy of 0.1 degrees. In addition, a symmetrical linear movement in two directions was to be realised with a single control unit, while at the same time the installation area was very tight.
• Industry: Medical technology
• Success for the customer: The design, which is based on a drylin® spindle linear unit, ensures that the linear movement can be performed with less friction and almost no clearance. This also had a positive effect on the robustness and precision of the system.

This machine was developed to produce high-precision telescope glasses for surgeons. For this purpose, two Galilean telescopes are attached very precisely to a pair of glasses. Each end product is customised exactly for one person and differs in various parameters such as the pupil distance. Specifically, the machine helps with the precise adjustment of the optical device by holding the system in three different positions.
To do this, the machine must be able to set precise angles with an accuracy of 0.1 degrees without the use of electronics. A calibration, testing and validation system also had to be installed. One of the critical problems in the design was to build a symmetrical linear movement in two directions with a single control unit. At the same time, the installation area was very tight.

A drylin® SLW spindle linear module was used to realise precise movement in two directions with a single control knob. The lead screw was replaced with a customised lead screw with right-hand and left-hand threads on one side and combined with drylin®-lead screw nut. The design ensured that the linear movement was performed with less friction and almost no clearance. This also had a positive effect on the robustness and precision of the system.
Today, a total of three drylin® linear guide systems are used for all linear movements.
For the precise angular movement, the mechanism comprised several high-precision gears that enabled very accurate positioning. Here, iglidur® double-collar bearings are used to align the gear shafts straight.