Patents by Inventor by Djurdjina Kojicic, legal representative

by Djurdjina Kojicic, legal representative has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Double walled screen-filter with perforated joints
    Patent number: 4649996
    Abstract: A well screen-filter includes a pair of substantially spaced concentric screens defining an annular filtrating space therebetween, connected with perforated joint(s) closing the lower end of the filtrating space. The annular space is filled with filtrating materials (gravel or synthetic balls) as a pack and an upper joint acts as a cover cap of the annular filtrating space to seal the pack. The lower perforated joint includes holes for passage of fine particles to a sedimentation tube, preventing clogging of the pack and enabling proper functioning of the double walled screen-filter.
    Type: Grant
    Filed: October 23, 1985
    Date of Patent: March 17, 1987
    Inventors: Bozidar Kojicic, deceased, by Djurdjina Kojicic, legal representative