Patent ID: 7572089

Claim:
A spring fastener comprising: (a) a substantially flat head portion comprising a first hole, the flat head comprising at least a lower side; (b) a neck having an opening and two side neck portions, a first side neck portion and a second side neck portion, the neck extending from the lower side of the substantially flat head portion at a substantially fight angle with respect to the substantially flat head portion; (c) a first leg and a second leg both legs being substantially flat and extending from the respective first side neck portion and second side neck portion, each leg having an inner surface, the two inner surfaces of the two legs being at an initial proximity with each other, such that the legs operatively expand in opposite directions upon inserting through the first hole an expansion member, thus bringing the expansion member to a contact region of the legs, each leg also having side leg portions; (d) a funnel configuration in the vicinity of the contact region; (e) at least one long barb having an origin at a region selected from one of the side neck portions, and one of the side leg portions, the at least one long barb also having a front point which front point substantially reaches or exceeds the lower side of the substantially flat head, the at least one long barb directed initially outwardly away from the legs and in sequence being bent at least firstly toward an inward direction; and (f) at least one short barb having an origin at a region selected from one of the side neck portions, and one of the side leg portions, the at least one short barb also having a front point which front point reaches lower than the lower side, the at least one short barb directed outwardly away from the legs.