[54] SELF-LIGATING ORTHODONTIC BRACKETS
[76] Inventor: G. Herbert Hanson, 57 Augusta St., Hamilton, Canada, L8N 1P8
[21] Appl. No.: 734333
[22] Filed: Oct. 22,1996
[51] Int CI.6 A61C 7/28
[52] U.S. CI 433/11
[58] Field of Search 433/10. 11. 13,
433/14. 17
[56] References Cited
U.S. PATENT DOCUMENTS
3,043,006 7/1962 WaUshein 433/11
3,076^65 2/1963 Moore 433/11
3,218,713 11/1965 WaUshein 433/11
3,772,787 11/1973 Hanson .
4,248,588 2/1981 Hanson 433/11
4,492,573 1/1985 Hanson 433/11
4,698,017 10/1987 Hanson 433/11
5,224,858 7/1993 Hanson 433/10
5,288,229 2/1994 Huffetal 433/17
5,344,315 9/1994 Hanson 433/20
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US005711666A [ii] Patent Number: 5,711,666 [45] Date of Patent: Jan. 27, 1998
[57] ABSTRACT
An orthodontic bracket comprises a bracket body with a mesial distal extending arch wire slot and a ligating latch spring member having the form of a thin flat metal strip. The spring member comprises along its length, in the order stated, an anchor portion anchored in the bracket body, a flexing portion in which the majority of the flexing takes place, a ligating portion that closes the slot mouth and engages any arch wire therein, and a latching portion by which the spring member is latched to the bracket body. The spring member may comprise a biasing portion between the flexing and ligating portions at the slot occlusal surface, or between the ligating and latching portions at the slot gingival surface, this biasing portion being convex toward the slot lingual wall and protruding into the slot to press the arch wire into the respective slot wall junction for more precise control. The bracket body may be made as two mirror image parts which are laser welded together and between which the spring member is mounted. The latches between the spring member and the bracket body may comprise notches in the spring edges that are engaged by latch sears on the body, and two labially lingually spaced sears may be provided. Preferably the spring member is made of a nickel titanium shape memory alloy. The bracket body may have two pairs of tie wings for reception of an external ligature between which the spring member is disposed.
21 Claims, 7 Drawing Sheets
