Reamer handle coupling
A coupling mechanism designed to removably attach a reamer to the distal end of a spindle or shaft is disclosed. The coupling comprises a collar having an annular sidewall that defines a collar throughbore, the collar annular sidewall comprising a plurality of spaced part first slots that at least partially extend through the sidewall and a shank disposed within the collar throughbore. The shank is constructed with a shank annular sidewall in which a plurality of spaced apart second slots at least partially extend therethrough. A bias member that provides a bias force in a distal direction that acts on the collar is incorporated within the mechanism. The collar is capable of sliding in an axial direction such that the first and second slots become aligned to secure the cross bar of a reamer therein.
1. A mechanism for connecting an instrument to a driver, the mechanism comprising:
a) a collar comprising a collar annular sidewall defining a collar throughbore that extends along a longitudinal axis A-A from a collar proximal portion having a collar proximal end and a collar annular sidewall proximal end to a collar distal portion having a collar distal end and a collar annular sidewall distal end, the collar annular sidewall having a collar annular sidewall thickness spaced between an interior collar sidewall surface and an exterior collar sidewall surface, wherein at least two spaced apart first slots extend through the collar annular sidewall thickness from the collar annular sidewall distal end part way to the collar annular sidewall proximal end and wherein an alignment slot extends longitudinally through the collar annular sidewall distal end partway to the collar proximal end;
b) a shank having a shank proximal portion with a shank proximal end that extends along the longitudinal axis A-A to a shank distal portion having a shank distal end, a cavity residing within the shank proximal portion and a shank annular sidewall that extends from the shank proximal portion to the shank distal end, the shank annular sidewall having a shank annular sidewall thickness that extends perpendicular to the longitudinal axis, wherein:
a. at least two spaced apart second slots extend through the shank annular sidewall thickness from the shank annular sidewall distal end part way to the shank annular sidewall proximal end;
b. the shank is disposed within the collar throughbore so that the collar is slidable in an axial direction along the longitudinal axis A-A with respect to the shank, the respective proximal and distal portions of the shank and collar oriented in parallel to the longitudinal axis A-A; and
c. a protrusion outwardly extends from an exterior surface of the shank, the protrusion extending longitudinally from a protrusion distal end at the shank distal end to a protrusion end spaced from the shank proximal end, wherein the protrusion is received within the alignment slot;
c) a pin having opposed first and second pin ends disposed within the shank cavity, wherein the first and second pin ends extend through opposing third slots that extend through a thickness of the shank proximal portion perpendicular to the longitudinal axis, and wherein the respective first and second pin ends are connected to the collar annular sidewall; and
d) a bias member disposed within the shank cavity proximal of the pin, wherein the bias member provides a bias force in a distal direction against the pin.
2. The mechanism of claim 1 , wherein the respective first and second pin ends are each received within openings that extends through the collar distal portion.
3. The mechanism of claim 1 , wherein the shank annular sidewall defines a distally extending opening within which at least a portion of an instrument is positionable.
4. The mechanism of claim 1 , wherein the at least two first slots are positioned diametrically opposed within the collar annular sidewall.
5. The mechanism of claim 1 , wherein the at least two second slots are positioned diametrically opposed within the shank annular sidewall.
6. The mechanism of claim 1 , wherein the first slot comprises a first slot opening portion that extends in a proximal direction to a first slot capture portion having a first slot capture portion proximal surface spaced from the collar proximal portion, wherein the first slot opening portion extends through the collar sidewall distal end oriented at a first slot opening portion angle with respect to the longitudinal axis A-A.
7. The mechanism of claim 6 , wherein the first slot opening portion angle extends between the longitudinal axis A-A and an imaginary plane that bisects a width of the first slot opening portion, and wherein the angle ranges from about 30° to about 60°.
8. The mechanism of claim 6 , wherein the first slot capture portion proximal surface has a radius of curvature that ranges from about 0.1 cm to about 2 cm.
9. The mechanism of claim 1 , wherein the second slot comprises a second slot cutout portion that extends through the shank annular sidewall at the shank distal end to a second slot traverse portion that extends about perpendicular to the longitudinal axis A-A.
10. The mechanism of claim 1 , wherein a first post extends along the longitudinal axis A-A from the collar proximal portion to a first post distal end with a first post distal end surface, the first post distal end surface extending between the interior and exterior collar sidewall surfaces at the first post distal end, and wherein the first post distal end surface is curved.
11. The mechanism of claim 1 , wherein an alignment slot is formed between a first post and a second post, the first post adjacent to the second post, the first and second posts extending lengthwise along the longitudinal axis A-A from the collar proximal portion to the collar distal end.
12. A mechanism for connecting an instrument to a driver, the mechanism comprising:
a) a collar comprising a collar annular sidewall defining a collar throughbore that extends along a longitudinal axis A-A from a collar proximal portion having a collar proximal end and a collar annular sidewall proximal end to a collar distal portion having a collar distal and a collar annular sidewall distal end, the collar annular sidewall having a collar annular sidewall thickness spaced between an interior collar sidewall surface and an exterior collar sidewall surface, wherein at least two spaced apart first slots extend through the collar annular sidewall thickness from the collar annular sidewall distal end part way to the collar annular sidewall proximal end and wherein an alignment slot extends longitudinally through the collar annular sidewall distal end partway to the collar proximal end;
b) a shank having an elongated shank proximal portion with a shank proximal end that extends along the longitudinal axis A-A to a shank distal portion with a shank distal end, a shank annular sidewall extending from the shank proximal portion to the shank distal end having a shank annular sidewall thickness oriented perpendicular to the longitudinal axis, wherein;
a. at least two spaced apart second slots extend through the shank annular sidewall thickness from the shank annular sidewall distal end part way to the shank annular sidewall proximal end;
b. the shank is disposed within the collar throughbore so that the collar is slidable in an axial direction along the longitudinal axis A-A with respect to the shank, the respective proximal and distal portions of the shank and collar oriented in parallel to the longitudinal axis A-A; and
c. a protrusion outwardly extends from an exterior surface of the shank, the protrusion extending longitudinally from a protrusion distal end at the shank distal end to a protrusion proximal end spaced from the shank proximal end, wherein the protrusion is received within the alignment slot of the collar so that the protrusion is slidable in an axial direction within the alignment slot;
c) a bias member disposed circumferentially around an exterior surface of the shank proximal portion, wherein the bias member provides a bias force in a distal direction against the collar; and
d) a locking ring having a locking ring annular sidewall that extends along the longitudinal axis A-A from a locking ring proximal end to a locking distal end, wherein the locking ring is connectable to the shank along the shank proximal portion, the bias member being positioned between the shank annular sidewall and the locking ring distal end.
13. The mechanism of claim 12 , wherein the shank annular sidewall defines a distally extending opening within which at least a portion of a cutting instrument is positionable.
14. The mechanism of claim 12 , wherein the at least two first slots are positioned diametrically opposed within the collar annular sidewall.
15. The mechanism of claim 12 , wherein the at least two second slots are positioned diametrically opposed within the shank annular sidewall.
16. The mechanism of claim 12 , the first slot comprises a first slot opening portion that extends in a proximal direction to a first slot capture portion having a first slot capture portion proximal surface spaced from the collar proximal portion, wherein the first slot opening portion extends through the collar sidewall distal end oriented at a first slot opening portion angle with respect to the longitudinal axis A-A.
17. The mechanism of claim 16 , wherein the first slot opening portion angle extends between the longitudinal axis A-A and an imaginary plane that bisects a width of the first slot opening portion, and wherein the angle ranges from about 30° to about 60°.
18. The mechanism of claim 16 , wherein the first slot capture portion proximal surface has a radius of curvature that ranges from about 0.1 cm to about 2 cm.
19. The mechanism of claim 12 , wherein the second slot comprises a second slot cutout portion that extends through the shank annular sidewall at the shank distal end to a second slot traverse portion that extends about perpendicular to the longitudinal axis A-A.
20. The mechanism of claim 12 , wherein a first post extends along the longitudinal axis A-A from the collar proximal portion to a first post distal end with a first post distal end surface, the first post distal end surface extending between the interior and exterior collar sidewall surfaces at the first post distal end, and wherein the first post distal end surface is curved.
21. The mechanism of claim 12 , wherein an alignment slot is formed between a first post and a second post, the first post adjacent to the second post, the first and second posts extending lengthwise along the longitudinal axis A-A from the collar proximal portion to the collar distal end.
22. The mechanism of claim 12 , wherein the locking ring comprises a locking ring protrusion that extends from an interior surface of the locking ring annular sidewall towards the longitudinal axis, wherein the locking ring protrusion is received within a locking groove that at least partially extends within an exterior surface of the shank proximal portion.