EP0446191A2
Expired / Lapsed
EP
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Torsional tightener for bone anchoring or implant elements/tools
Assignee: Nobel Biocare AB
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Filing: 1991-02-27
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Granted: —
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Expires: 2011-02-27
Abstract
Abstract A torsional tightener (101) is used, inter alia, for anchoring elements (108) in implants (103) anchored in bone. The tightener is releasable at a previously set torque and comprises an electric motor (406), a unit (403) changing the speed down, and a torsional tightening part. For the purpose of achieving a well-defined set torque value, the energy supply circuit of the electric motor can be interrupted at a certain current value in the energy supply circuit. The interruption and the rotational energy in the rotating parts of the torsional tightener after interruption are designed to cause a torsional tightening moment which is situated at or near an optimal or desired point on the particular moment curve for the tightening in question. Alternatively, a disconnection part is used, which interrupts the tightening function at or near the desired point on the moment curve.
Inventors
- 👤 Lennart Carlsson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 00:15
CPC Classifications
B; B25; B25B; B25B23/00; B25B23/14; A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/88; A61B17/8875; A61C; A61C8/00; A61C8/0089; B25B23/147; A61C1/00; A61C1/08; A61C1/18; A61C1/185; A61C1/186
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
280 words
Torsional tightener intended for anchoring elements/tools (108, 203) in bone or in implants (103) anchored in bone, especially dentine (102) or dental implants, which torsional tightener (401) is releasable at a previously set torque and comprises an electric motor (406) operating at high speed, connected to this a unit (403) changing the speed down, and a torsional tightening part (101, 201) which is actuated by the unit and cooperates with the element, the electric motor being supplied with electrical energy (i) which increases as a function of a torsional resistance from the element/tool growing during the process of tightening of the element/tool, and the set torque is/can be determined by means of a predetermined parameter value of the supplied increasing electrical energy, characterised in that, in order to achieve a well-defined set/settable torque value, the torsional tightening is designed in accordance with one of the following two alternatives: a) the energy supply circuit (603, 604) of the electric motor can be interrupted at said predetermined parameter value, and the interruption and the rotational energy in the rotating parts of the torsional tightener after interruption are designed to bring about a torsional tightening moment which is situated at or near an optimal or desired point (302) on the particular moment curve (303, 305, 306) for the tightening in question, b) the torsional tightening part is connected to the unit (403), changing the speed down, via a disconnection part (701) which is actuable at said predeterminable parameter value, which is in this case chosen to cause a torsional tightening moment which is situated at or near an optimal or desired point (302) on the particular moment curve for the tightening in question.
Claim 2
Dependent Claim
45 words
Torsional tightener according to Claim 1, characterised in that the interruption of electrical energy is designed to occur close to the optimal or desired point ( 302 ), and the rotational energy after interruption has only a marginal effect on the finally obtained torque value.
Claim 3
Dependent Claim
23 words
Torsional tightener according to Claim 1 or 2, characterised in that the high-speed electric motor (406) is designed with a small rotating weight.
Claim 4
Dependent Claim
55 words
Torsional tightener according to Claim 1, 2 or 3, characterised in that, in the case where the growing torsional resistance for the element is effected principally during ¼ to ½ a turn, the effect of the rotational energy after interruption is chosen such that it rotationally affects the element/tool after interruption by at most 10°.
Claim 5
Dependent Claim
44 words
Torsional tightener according to any one of the preceding claims, characterised in that it comprises or can be connected to a unit for setting the torque, at which release is desired to take place, and for indicating when the respective set value is reached.
Claim 6
Dependent Claim
63 words
Torsional tightener according to Claim 5, characterised in that the setting and indicating unit is designed with a liquid-crystal gauge, for example first optical elements (506, 507, 508) arranged one after the other, on which gauge the growing torque effect from the torsional tightener on account of growing torsional resistance during the process of tightening of the element/tool (101, 201) can be monitored.
Claim 7
Dependent Claim
53 words
Torsional tightener according to Claim 5 or 6, characterised in that it has first indicating elements (509, 510, 511, 512), for example second optical elements, which indicate different values of the set torque, and in that the first indicating elements are arranged close to and alongside the said liquid-crystal gauge (506, 507, 508).
Claim 8
Dependent Claim
105 words
Torsional tightener according to Claim 5, 6 or 7, characterised in that each growing torque effect can be monitored on the liquid-crystal gauge which has, opposite the indicating elements (509, 510, 511, 512) which indicate the different values of the set torque, other indicating elements so that, when the torque from the torsional tightener has reached the respective set value, the first optical elements which represent values lying under the set value are activated, and in that a third indicating element (513) at the upper end of the liquid-crystal gauge is designed so as to be actuable when the respective set value has been reached.
Claim 9
Dependent Claim
42 words
Torsional tightener according to any one of Claims 5-8, characterised in that the setting and indicating unit (501) is designed with setting of two or more output speeds (518, 519, 520 and 521, 522, 523) for the said torsion-effecting part (101, 201).
Claim 10
Dependent Claim
79 words
Torsional tightener according to any one of the preceding claims, characterised in that the energy supply circuit of the electric motor is sensed by a circuit (605) sensing the current of the electric motor, which circuit (605) is actuable when the current (i) reaches a value depending on the setting, and in that, when the last-mentioned value occurs, the sensing circuit is designed to cause interruption or breaking of the energy supply circuit (603, 604) of the electric motor.
References Cited (Backward Citations)
No citation records indexed.
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