| 摘要 |
Improved mounting of a rack, constituent means and applications. The rack 10 has the shape of a hollow oval body 11 with ribs 13, 13a jutting out and has a toothed rake 9. The teeth 9 are guided by rollers 12. According to the invention one or several tracks S are provided which prevents the rollers from becoming stuck due to accumulation of grease and dust in the rack. Application to the control of opening and closing devices of windows for long length greenhouses. <IMAGE> |
