Device for securely attaching a drilling device to a drill plate including an expandable collet with balls

A device for securely attaching a drilling device to a drill plate traversed by a plurality of positioning bores, said device for securely attaching comprising:

• a body;
• a first attachment to securely attach said body to said drilling device;
• a second attachment to securely attach said body to said drill plate, said second attachment comprising an expandable collet, said expandable collet comprising:
• an expandable ring traversed by a conical bore made along a longitudinal axis of said expandable ring;
• an expansion cone housed within said conical bore of said expandable ring, an external peripheral outline of said expansion cone being complementary to said conical bore,
• a translational drive, which drives in translation said expansion cone within said conical bore along said longitudinal axis between at least:
• a releasing position in which said cone is shifted to a largest-diameter side of said conical bore of said expandable ring so much so that said expandable ring is in a relaxed state in which the expandable ring's external diameter is smaller than a diameter of said positioning bores so that said expandable ring can be inserted therein or extracted therefrom;
• a locking position in which said cone is shifted to a smallest-diameter side of said conical bore of said expandable ring so much so that said expandable ring is in an expanded state in which the expandable ring's external diameter is increased so as to keep said device for securely attaching securely attached to said drill plate by friction of said expandable ring against internal walls of one of said positioning bores;
• wherein said expandable collet furthermore comprises locking balls each housed in a hole made in said expandable ring, said expansion cone acting on said locking balls to place them in:
• an unblocking position, taken when said cone is situated in the cone's releasing position, in which said locking balls do not form protrusion on an external peripheral surface of said expandable ring;
• a blocking position, taken when said cone is situated in the cone's locking position, in which said locking balls form protrusions on the external peripheral surface of said expandable ring so that said locking balls can get housed in a peripheral blocking housing securely attached to said positioning bores.