A hook for suspending or supporting, from a rod or wire, a retractable roof covering used on greenhouses, comprises a pin for engaging the covering, a separator for preventing the covering material from contacting the rod or wire, and a locking mechanism for locking the pin and preventing the ...http://www.google.com/patents/US5761776?utm_source=gb-gplus-sharePatent US5761776 - Locking hook with integral separator
