JP2003525686A - Connecting device for equipment components - Google Patents

Abstract

(57) A device for connecting a device and / or an implant to: A) a connecting pin (4) and B) a bush (3) for receiving a connecting pin (4), C) The coupling pin (4) has n planes (11) on its outer circumference, and correspondingly the hole (20) includes n inner surfaces (21), so that the coupling pin (4) has the hole ( 20) can be inserted with no play in torsional rigidity, D) the coupling pin (4) has a radially elastic tongue (19) and at least one cam (17) projecting radially; E) the tongue (19) is radially compressible so that the coupling pin (4) can be inserted into the hole (20); and F) when the coupling pin (4) is inserted, at least one The cam (17) can be snap-fit into the recess (27), so that the connecting pin (4) is G) cam (17) and recess (27) such that when a tensile force of value X acts on the coupling pin (4), the tongue (19) can be compressed in the radial direction. Is configured.

Description

Detailed Description of the Invention

TECHNICAL FIELD The invention relates to a coupling device for instrument components according to the preamble of claim 1 for coupling instruments, in particular surgical instruments and / or implants.

BACKGROUND ART A coupling device for coupling a reamer tool to a driving machine is US Pat. No. 5,720,749 RUP.
Known by P. The known reamer tool is particularly useful for drilling a medullary cavity in bone and includes a tool head which is substantially removably connectable to a rotationally drivable flexure shaft. The connecting part is composed of a tubular bush on the cutting tool side and a tubular pin which can be pushed into the hole of the bush on the bending shaft side. The bushing and the pin are constructed essentially as hollow cylinders, the outer peripheral surface of the pin and the inner peripheral surface of the bushing being provided with two parallel and corresponding surfaces for part of their length. These surfaces terminate short of the front end on the coupling side, with two cams at this end of the pin. Furthermore, the wall of the pin is provided with an axial slot, thus creating an elastic tongue. When the pin is pushed into the bush, both tongues with the cam are radially compressed, and when the pin is pushed completely the cam snaps into the corresponding circumferential slot through the wall of the bush. Become. The pin is thus rotatably held axially in the bush. To remove the tool head, the elastic tongue of the pin is compressed from the outside of the bush through the circumferential slots, the cam disengages from these slots and the pin can be pulled out of the bush. A disadvantage of this known device is that it requires the use of a special device for compressing the elastic tongue through the circumferential slot to disassemble the tool head. Furthermore, the connection between the shaft and the pin is a press connection, so that the guide wire or Kirschner wire threaded through the hole in the pin can only rotate with considerable frictional losses.

In this regard, the present invention seeks to provide a remedy. It is an object of the present invention to provide a coupling device which enables the assembly and disassembly of mutually connectable parts without auxiliary tools or devices. Furthermore, the coupling device has the property that, in the assembled state, axial and rotational interruptions occur in both directions.

DISCLOSURE OF THE INVENTION The present invention solves the problem posed by an apparatus for connecting instruments, in particular surgical instruments and / or implants, having the features of claim 1. Other advantageous configurations of the invention are specified in the dependent claims.

The device according to the invention for connecting surgical instruments and / or implants comprises a connecting pin and a bushing having a hole for receiving the connecting pin, the peripheral surface of the connecting pin being at a distance from the front end. It has n faces starting from A and extending for a length L parallel to the longitudinal axis, correspondingly the hole in the bush comprises n wall faces and the connecting pin extends longitudinally in the hole without play. Acceptable with torsional rigidity around the axis.
The connecting pin includes at least one radial slot that extends through from the front end to the depth T, thus creating a radially elastic tongue from the front end to the depth T. Further, the peripheral surface includes at least one cam projecting radially from at least one of the connecting pins or faces towards the front end of the connecting pin. When the tongue piece is compressed, the tongue piece is so large that the connecting pin can be inserted from the rear end of the bush into the hole portion having n wall surfaces, and can be snap-fitted into the recess provided in the hole and corresponding to the cam. It is radially compressible, so that an axial stop of the connecting pin can be achieved in the bush. The means included in the cam and the concave portion are such that the cam is disengaged from the concave portion and the coupling pin can be pulled out from the hole of the bush when at least the pulling force of the value X acts toward the rear end of the bush and acts on the coupling pin. Allow the tongue to be radially compressible. The tensile force required to compress the tongue is preferably 1-50N.

These means consist in that the cam configuration is axially convex in one embodiment, or in another embodiment the cam / cams are axially wedge-shaped with a connecting pin at an angle α. Is connected to at least one of the planes in.

The angle α is 15 ° to 85 °, preferably 25 ° to 3 in any of the above embodiments.
It can be 5 °.

In one embodiment of the device according to the invention, the connecting pin can be connected to a drive shaft which is rotatable about its longitudinal axis, and the bush can be fitted with a reamer tool, for example.

In a preferred embodiment of the device according to the invention, the peripheral surface of the coupling pin is of cylindrical shape and the cam is formed by providing n planes on the peripheral surface, said planes being radial to the peripheral surface. Partially depressed in the direction. The recess is configured as an undercut and adjoins the hole with the wall. The undercut leads into the wall of the hole towards the rear end with the first cone inner surface, the semi-tapered angle of the first cone inner surface preferably coincides with the angle α.

In another embodiment of the device according to the invention, the end face of the front end of the undercut is orthogonal to the longitudinal axis and is configured as a flat end face. When the connecting pin is inserted, the front end of the connecting pin comes into contact with the end face orthogonal to the longitudinal axis of the undercut.

In another embodiment of the device according to the invention, at least one of the cams is wedge-shaped with its front end extending parallel to the longitudinal axis and makes an angle β with respect to the longitudinal axis towards the front end. In any of the above embodiments, the angle β is 15 ° to 85 °, preferably 2 °.
It can be 5 ° to 35 °.

In another embodiment of the device according to the invention, the undercut leads to a hole in the bush at the inner surface of the second cone towards the front end, the semi-tapered angle of the inner surface of the second cone preferably matching the angle β. Upon insertion of the connecting pin, the wedge-shaped cam abuts the inner surface of the second cone of the undercut at the front end of the connecting pin.

[0013] Preferably, the axial lengths of the cam and the undercut are matched so that when the cam is snap-fitted into the undercut, the connecting pin causes axial stop in the bush in both directions.

In another embodiment of the device according to the invention, the coupling pin has a hole coaxial with the longitudinal axis, and a guide wire or Kirschner wire can be mounted coaxially with the longitudinal axis through the coupling pin and the bush.

The advantages achieved by the invention are substantially that the device according to the invention allows the two components of the surgical instrument to be simply and without additional aids and to be separated again. In point. Furthermore, the guide wire or the Kirschner wire can be inserted through the connecting pin and the bush when in the connected state, and no friction loss occurs when the device rotates relative to the guide wire or the Kirschner wire. This device, when in the connected state, allows a connection that does not permit rotation or axial sliding of the connecting pin relative to the bush.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention and various configurations of the present invention will be described in detail based on a plurality of embodiments partially shown in schematic drawings.

A preferred embodiment of the coupling device 1 according to the invention is shown in cross section in FIGS. 1 and 2. For example, a bush 3 having a tool head 2 of a reamer tool and a coupling pin 4 of a flexure drive shaft 5 are detachably coupled to each other by a coupling device 1, and the bush 3 is coupled in a coupled state.
And the connecting pin 4 are axially fixed so as to be rotatable relative to each other. Coupling pin 4
Is configured as a hollow cylinder and has a longitudinal axis 10, a rear end 7 facing the shaft, and a front end 8 opposite the drive shaft 5. The axial bore 15 of the connecting pin 4 serves to receive a guide wire or Kirschner wire 16. The outer peripheral surface 9 of the connecting pin 4 is substantially cylindrical, has a diameter D and comprises six planes 11. Each two of these planes 11 are symmetrical about the longitudinal axis 10. In the embodiment described here of the device according to the invention, the dihedral width S between two parallel planes 11 is smaller than the diameter D of the coupling pin 4 and is chamfered between two adjacent planes 11 to form a peripheral surface 9. Ridge 12 above
Is set to occur. Again from the front end 8 to the connecting pin 4 the longitudinal axis 1
In parallel with 0, four slots 18 symmetrically distributed on the peripheral surface of the coupling pin 4 are provided up to the depth T, thus giving four tongues 19 which can be bent in the radial direction. The length L of the flat surface 11 in the axial direction extends from the front end 8 to the rear end 7 after the distance A, and the cam 17 is formed in the portion of the outer peripheral surface 9 extending from the front end 8 to the distance A. Transition 1 that occurs between the surface 11 and the outer peripheral surface 9 across the longitudinal axis 10.
Reference numerals 3 and 14 are wedge-shaped, and an angle α of 30 ° is contained between the front transition portion 14 communicating with the cam 17 and the longitudinal axis 10. The front end 8 of the cam 17 is wedge-shaped parallel to the longitudinal axis 10 and the cam 17 forms an angle β of 30 ° between the front end 8 and the longitudinal axis 10.

The bush 3 has a shaft-side rear end 22 and a front end 23, and has a maximum of length L in its hole 20 aligned with the longitudinal axis 10 corresponding to the plane 11 of the connecting pin 4. The connecting pin 4, which has a flat wall surface 21 and is fitted into the hole 20 of the bush 3, is fixed against rotation about the longitudinal axis 10. Adjacent to the front end 23, the hole 20 of the bush 3 is provided in the wall surface 21 with an undercut 24, the end face 25 of the undercut 24 towards the front end 23 is orthogonal to the longitudinal axis 10 and the undercut 24 of the rear end 22. The inner surface 26 of the first cone is connected to the wall surface 21. The half taper angle of the inner surface 26 of the cone is the cam 1
7 corresponds to the angle α of the transition portion 14. The wall 21 extends in a wedge shape parallel to the longitudinal axis 10 and leads to the rear end 22 of the bush 3, the wedge angle preferably corresponding to the angle β, which is also 30 °.

This configuration of the bushing 3 and the connecting pin 4 allows the connecting pin to be pushed into the hole 20 from the rear end 22 of the bushing 3 and projects radially from the wall surface 21 of the cam 17.
Can be inserted into the bush 3 by radial compression of the flexible tongue 19. Cam 17
When the connecting pin 4 is inserted into the hole 20 until the is in the area of the undercut 24, the tongue piece 19 returns and the cam 17 snaps into the undercut 24. Coupling pin 4
The front end 8 is the end face 25 of the undercut 24 when the bush is snap-fitted to the bush 3.
Against the front end 23 of the bush 3 is formed by the abutment against the axial end of the bush 3 and the connecting pin 4 is axially stopped by the inner surface 26 of the cone and the transition 14 with respect to the rear end 22 of the bush 3. When the width of the cam 17 formed by the distance A matches the width of the undercut 24, the coupling pin 4 is stopped in both directions in the snap-fit state for axial sliding. Furthermore, the wedge shape of the transition 14 of the connecting pin 4 and the conical inner surface 26 of the undercut 24 allow the flexible tongue 19 to be moved by applying an axial pulling force on the connecting pin 4 towards the rear end 22 of the bush 3. It is radially compressed, which allows the cam 17 to disengage from the undercut 24, and thus the connecting pin 4
Can be pulled out of the bush 3. The angle α between the inner surface 26 of the first cone and the transition 14 is preferably chosen so as to exert a greater axial force in order to compress the flexible tongue 19 than would appear during normal use of the device. ing. further,
Insertion of the guide wire or Kirschner wire 16 into the hole 15 of the connecting pin 4 makes the flexible tongue 19 less elastic, and during normal use the connecting pin 4 is additionally cammed by the cam 17 at the rear end 22 of the bush 3. Fixed towards.

One embodiment of the device according to the invention shown in FIG. 3 is that the undercut 24 faces the front end 23 of the bush 3 and leads into the hole 20 at the second cone inner surface 30 and the half taper of the second cone inner surface 26. It differs from the embodiment shown in FIG. 1 only in that the angle corresponds to the angle β.

The embodiment of the device according to the invention shown in FIG. 4 comprises four coaxial segments 24; 25; 26; 30 in which the coupling pin 4 is axially adjacent to each other between the rear end 7 and the front end 8. This point is different from the embodiment shown in FIGS. 1 and 2. The first segment 24 adjacent to the rear end 7 has a cylindrical shape, and the rear end 7 can be connected to a drive shaft (not shown). The second segment 25 is adjacent to the first segment 24 toward the front end 8. The second segment 25 is formed in a prismatic shape with a hexagonal cross section, the corner size of the hexagon is smaller than the outer diameter of the first segment 24, and the transition portion from the first segment 24 to the second segment 25 is a half taper. It has a conical shape with an angle γ = 45 °. Further, the cylindrical third segment 26 joined adjacent to the second segment 25 toward the front end 8 has an outer diameter smaller than the width across flats of the hexagonal second segment 25. The transition between the second segment 25 and the third segment 26 is also conical with a half taper angle δ of 45 °. The fourth segment 30 adjacent to the third segment 26 and reaching the front end 8 has a larger outer diameter than the third segment 26, while the half taper angle α =
A cone of 30 ° leads to the third segment 26, while a cone of half taper angle β = 30 ° terminates at the front end 8. The connecting pin 4 has a coaxial hole 15 extending from the front end 8 to the depth T and a wall of the connecting pin 4 between the hole 15 and the outer peripheral surface 9 also extending from the front end 8 to the depth T with respect to the longitudinal axis 10. And three slots 18 separated in parallel. The radial compressibility of the connecting pin 4 at the depth T is achieved by the slot 18, the connecting pin 4 having the function of a radial elastic clamping part 29 in this axial part.

Since the outer diameter of the fourth segment 30 is larger than that of the third segment 26, the bent grooved wall of the connecting pin 4 allows the three cams 17 protruding in the radial direction as compared with the third segment 26 to be formed. It is formed. The bushing 3, which is complementary to the coupling pin 4, can, for example, be coupled at its front end 23 to a surgical instrument (not shown). Toward the rear end 22 of the bush 3, the hole 20 has a hexagonal hole 16, which when joining the bush 3 forms a torsionally rigid connection with the second segment 25 of the connecting pin 4 with respect to the longitudinal axis 10. To do. The hexagonal hole 16 is conical with the end face of the rear end 22 of the bush 3 complementary to the conical transition between the first segment 24 and the second segment 25. Towards the front end 23 of the bush 3, the hole 20 comprises a cylindrical recess 27, which comprises a frustoconical part which delimits the recess 27 with respect to the hole 20, which frustoconical part comprises a third segment 26 and a fourth segment. It complements the conical transition between the segment 30 and the conical opening into the bore 20. When the front end 8 of the connecting pin 4 is inserted into the hole 20 of the bush 3, the radially elastic clamping part 29 of the connecting pin 4 is radially compressed, and the cam 17 is axially moved by the cylindrical intermediate part of the hole 20. Towards the front end 23 of the cam, the cam can slide until it reaches the recess 27, whereupon the elastic clamping part 29 can elastically return to its non-compressed starting position again and the cam 17 engages the recess 27. The connecting pin 4 thus has a torsional rigidity with respect to the longitudinal axis 10, is fixed so as not to slide in the axial direction and is supported in the bush 3. When a sufficiently large pulling force is applied to the connecting pin 4 in the direction of the rear end 23 of the bush 3, the cam 17 moves on the one hand to the third segment 2 of the connecting pin 4.
6 and the fourth segment 30 and, on the other hand, radially compressed by the complementary conical transition between the hole 20 and the recess 27, the connecting pin 4 is axially arranged in the rear end 23 of the bush 3.
It can be pulled out from the bush towards.

[Brief description of drawings]

1 is a longitudinal section view of a preferred embodiment of the device according to the invention.

2 is a cross-sectional view of the embodiment shown in FIG. 1 of the device according to the invention.

FIG. 3 is a longitudinal sectional view of another embodiment of the device according to the present invention.

FIG. 4 is a perspective view of a coupling pin including a cross section of a bushing of another embodiment of a device according to the present invention.

Claims (25)

[Claims] 1. A device and / or implant comprising: A) a connecting pin (4) comprising a rear end (7), a front end (8), a longitudinal axis (10) and a peripheral surface (9); and B) a rear end. (22), front end (23) and longitudinal axis (10) coaxially with a coupling pin (
4) A device for coupling with a bush (3) having a hole (20) for receiving 4), wherein the peripheral surface (9) of the coupling pin (4) is parallel to the longitudinal axis (10). Has n planes (11) starting at a distance (A) from the front end (8) and extending from there by a length (L), corresponding to these planes the holes (20) of the bushing (3). Is at least n
A wall surface (21), so that the connecting pin (4) is inserted into the hole (20) along the longitudinal axis (
10) It can be inserted with torsional rigidity around D) and D) a connecting pin (4) is coaxial with the longitudinal axis (10) and has a hole (15) reaching from the front end (8) to at least the depth (T). At least one radial slot (18), so that the coupling pin has a radially elastically compressible clamp (29) from the front end (8) to the depth (T), E) The coupling pin (4) comprises at least one cam (17) projecting radially, G) the hole (20) is at least one cam (17) at the front end (23) of the bush (3).
) With a recess (27) complementary to which the cam (17) can snap fit, so that the coupling pin (4) can be axially locked in the bush (3). H) by means (28) of cam (17) and recess (27).
When a pulling force of at least the value X towards the rear end (22) acts on the connecting pin (4), the tightening part (29) becomes radially compressible and thus the cam (17) is recessed (
27) Disengaging from the connector 27, the connecting pin (4) can be pulled out from the hole (20). 2. Device according to claim 1, characterized in that the rear end (7) is connectable to the drive shaft (5). 3. Device according to claim 1 or 2, characterized in that the bush (3) is connectable to the reamer tool (2). 4. The device as claimed in claim 1, wherein the means (28) is constructed such that at least one cam (17) is configured to be convex in the axial direction. 5. The means (28) comprises a wedge-shaped part in which at least one cam (17) extends parallel to the longitudinal axis (10) and leads to one of the planes (11) at an angle α. Device according to any one of claims 1 to 3, characterized in that 6. At least one cam (17) extends parallel to the longitudinal axis (10) including a wedge-shaped portion located at the front end (8), the cam (17) being at the front end (8).
8. Forming an angle β with respect to the longitudinal axis (10) at 8).
6. The device according to any one of to 5. 7. Device according to claim 1, characterized in that the connecting pin (4) comprises n cams (17). 8. The angle α is in the range of 15 ° to 85 °.
The apparatus according to claim 1. 9. The angle α is in the range of 25 ° to 35 °.
The described device. 10. The tensile force is 1 to 50 N, as claimed in claim 1.
9. The device according to any one of 9 above. 11. The device according to claim 6, wherein the angle β is between 15 ° and 85 °. 12. Device according to claim 11, characterized in that the angle β is between 25 ° and 35 °. 13. Device according to claim 1, characterized in that the recess (27) is an undercut (24). 14. Device according to claim 13, characterized in that the undercut leads to at least one wall surface (21) at the inner surface (26) of the first cone. 15. Device according to claim 14, characterized in that the half taper angle of the inner surface of the first cone (26) corresponds to the angle α. 16. The undercut (24) according to any one of claims 13 to 15, characterized in that it has a flat end face (25) facing the front end (23) and orthogonal to the longitudinal axis (10). The device according to item 1. 17. Device according to claim 14, characterized in that the undercut (24) leads into the hole (20) at the second conical inner surface (30) towards the front end (23). 18. Device according to claim 17, characterized in that the semi-tapered angle of the inner surface (26) of the second cone corresponds to the angle β. 19. The connecting pin (4) has a continuous hole (15) coaxial with the longitudinal axis (10) and the guide wire or Kirschner wire (16) coaxial with the longitudinal axis (10). Device according to any one of claims 1 to 18, characterized in that it can be inserted through (4) and the bush (3). 20. Device according to claim 1, characterized in that the connecting pin (4) has a polygonal cross section over the length of the length (L). 21. Device according to claim 20, characterized in that the connecting pin (4) has a hexagonal cross section in the length section of the length (L). 22. The wall surface (21) is expanded in the shape of a wedge in the axial direction, and the bush (3) is formed.
) Leading to the rear end (22) of any one of claims 1 to 21.
The device according to the item. 23. Device according to claim 22, characterized in that the wedge angle corresponds to the angle β. 24. The connecting pin (4) comprises at least one cam (17) towards the front end (8), which cam axially follows n planes (11) and n planes (11). Device according to any one of claims 1 to 23, characterized in that it projects radially from at least one of 11). 25. The hole (20) comprises a recess (27) towards the front end (23) of the bush (3), which recess axially adjoins at least n wall surfaces (21), and It corresponds to at least one cam (17), and the cam (1
25. Device according to claim 24, characterized in that 7) is snap-fittable and that the connecting pin (4) can be axially locked in the bush (3).