Production of surgical spectacles

Profile

• What was needed: drylin SLW lead screw modules
• Requirements: The machine had to guarantee high machine precision when adjusting the angle 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 keeping the installation area very tight.
• Industry: medical equipment
• Success for the customer: The design, which is based on a drylin lead screw 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.

Problem

This machine was developed to produce high-precision teleloupe spectacles for surgeons. For this purpose, two Galilean loupes are attached very precisely to a pair of glasses. Each end product is tailored exactly to one person and differs in various parameters such as the distance between pupils. Specifically, the machine helps with the precise adjustment of the optical device by holding the system in three different positions.
For this purpose, it must be possible to set precise angles on the machine with an accuracy of 0.1 degrees without the use of electronics. A calibration, test and validation system also had to be installed. One of the critical problems during the design stage was to construct a symmetrical, linear motion in two directions with a single control unit. At the same time, the installation area was very tight.

Solution

A drylin SLW lead screw linear module was used to produce a precise movement in two directions with a single control knob. The lead screw was replaced by a customised lead screw with right-hand and left-hand threads on one side and combined with drylin lead screw nuts. The design was able to ensure 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 precise angular movement, the mechanism included several high-precision gearboxes that enabled very accurate positioning. Here, iglidur double flange bearings are used to set the gear shafts straight.