AU5339590A

AU5339590A - Coupling

Info

Publication number: AU5339590A
Application number: AU53395/90A
Authority: AU
Inventors: Ronald Edmond Eaton
Original assignee: Wallis Industries Pty Ltd
Current assignee: Wallis Industries Pty Ltd
Priority date: 1989-03-28
Filing date: 1990-03-20
Publication date: 1990-10-22
Anticipated expiration: 2010-03-20
Also published as: AU637363B2

Description

COUPLING

THIS INVENTION relates to a coupling and in particular a coupling means for fixing a male member to a female member.

In one form the invention resides in a coupling means for fixing a male member of substantially circular cross- section to a female member of complementary configuration, one of said members being formed with a helical groove to be in opposed relation to a correspondingly configured helical formation on the other member when the members are inter-engaged, a plurality of locking elements of substantially complementary configuration to the profile of the helical groove and helical formation being receivable between the helical formation and the helical groove on engagement of the male and female members.

According to one embodiment the helical formation comprises a helical array of apertures.

According to another embodiment the helical formation is formed as a continuous helical recess terminating short of the end/or ends of the one member.

According to a further embodiment the helical formation comprises a set of groove shaped recesses.

In each of the embodiments each locking element may be shaped as a ball.

In each of the embodiments the locking element may be cubic in shape.

In each of the embodiments the locking element may be substantially cylindrical in shape.

SUBSTITUTE SHEET According to a preferred feature a set screw is receivable in the female member to be engagable with one or more locking elements received between the helical groove and the helical formation and the members are substantially fully engaged to cla pingly engage the locking element between the male and female members.

The invention will be more fully understood in the light of the following description of several specific embodiments.

The description is made with reference to the accompanying drawings of which;

Figure 1 is a side elevation of a male member according to the first embodiment;

Figure 2 is a sectional side elevation of a female member of the first embodiment;

Figure 3 is a sectional side elevation of the male and female members when inter-engaged;

Figure 4 is a side elevation of a male member according to the second embodiment; and

Figure 4 is a side elevation of a female member according to the third embodiment.

Each of the embodiments relates to a means for effecting a coupling between two components which is intended to supplement and/or replace the conventional threaded interconnection which is used between a male and female member of complementary con iguration. In instances where a threaded interconnection is required for a component which is involved in a transmission of large impact and/or torsional forces a threaded connection can provide the most effective interconnection, however by the nature of its inter-engagement and the high frictional forces which are established between the members, several difficulties can be experienced when it becomes necessary to separate the two components.

The first embodiment provides a male member 11 and a female member 12 of complementary configuration. The female member is formed with a helical groove 13 which has a part circular profile. The male member is formed with a helical formation in the form of a helical array of recesses 14. Each recess has a part spherical configuration. The helical array of recesses is complementary in its pitch to the helical groove 13 provided on the male member. Each of the recesses 14 receives a ball 15 having a configuration conforming to the profile of the recess and of the helical groove 13. The recesses 14 have a depth of less than the diameter of the balls in order that a portion of the surface of a ball received within a recess will extend beyond the surface of the male member. On engagement of the male member- 11 with the female member 12, the first recess to enter the female member is aligned with the entry to the helical groove 13 and a ball 15 is engaged therewith in order to enter the groove. With further engagement of the male member relative rotation is produced between the male and female member in order that the first ball 15 travels along the helical groove until the next recess is located at the entry of the helical groove 13 at which time a second ball 15 is located in the next recess. This action is repeated until the engagement between the male and female members is completed. — A . —

If desired the female member may be associated with a set screw (not shown) which is threadably received in an aperture provided in the wall of the female member which is in alignment with one of the recesses when the male and female members are fully engaged. The engagement of the set screw with the ball located in the respective recess produces a clamping engagement of the ball between the male and female members to frictionally lock the members together.

In the case of the second embodiment as shown at Figure 4 the helical formation on the male member may take the form of a continuous helical groove shaped recess 114 of corresponding pitch to the helical groove on the female member but of a fixed length and which terminates short of the end of the male member. On engagement of the male member 111 with the respective female member (not shown) the adjacent end of the helical recess is aligned with the entry to the helical groove provided in the female member and a ball is located therebetween. On further engagement of the male member with the female member and on relative rotation between the male member and female member additional balls are inserted into the space between the helical groove and helical recess until the helical recess is fully received in the male member.

As in the case of the first embodiment, if desired a set screw can be threadably received through an aperture in the wall of the female member to be in alignment with the helical groove and helical recess when the male and female members are fully engaged. The set screw is thus engagable with one or more of the balls located between the male and female members to clampingly engage the ball between those members and thus frictionally lock the members together. In the case of the third embodiment as shown at Figure 5 the helical formation takes the form of a series of helically disposed groove shaped recesses 214 which together define a helical formation of complementary configuration to the helical groove in the female member (not shown) . On engagement of the male member 211 with a respective female member and as each recess 215 is brought into engagement with the entry of the helical groove provided in the female member an appropriate number of balls are located in the space therebetween on relative rotation between the male and female member such that the spaces so formed are substantially filled with such balls. This process is completed until the male members and the female members are fully inter-engaged. As in the case in the previous embodiment a set screw may be provided in the female member to clampingly engage one or more of the balls accommodated between the male and female members.

It should be appreciated that in the case of each of the above embodiments that if desired the balls as described may be substituted by any suitable regularly shaped element. For example the element may be cylindrical in shape and the configuration of the helical formation be such that the elements are received such that their central axes are substantially radially directed with respect to the male member. As a result the helical groove provided in the female member has a substantially square shaped profile to snugly receive the exposed ends of the locking elements. Alternatively, in the case of a locking element having a substantially cylindrical configuration the locking elements may be located within the helical formation such that the central axes of the locking elements are substantially tangential. In that instance the profile of the helical formation and the helical groove will conform to the curved configuration of the cylindrical elements. It should be appreciated however, that other shapes (e.g. cubic shapes) of the locking elements may be utilised depending upon the nature of the circumstances.

In addition, while each of the embodiments has been described as having the helical formation on the male member and the helical groove on the female member it is also possible for the helical formation to be located on the female member and the helical groove to be located on the male member if the circumstances so require or permit.

As a result of the embodiment a coupling is provided which can withstand considerable impact and torsional forces but which, due to the relatively small contact area between the male member and female member provided by the locking element, is relatively easily disassembled. The embodiment has particular advantage in the drilling industry to provide for the coupling of drilling components to drill strings and the like. The embodiment also has application as a replacement for standard threaded connections which are subject to high loads such as impellers on large centrifugal pumps, propellers, or shafts and like components.

It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiments described above.

Claims

THE CLAIMS defining the invention are as follows:

1. A coupling means for fixing a male member of substantially circular cross-section to a female member of complementary configuration, one of said members being formed with a helical groove to be in opposed relation to a correspondingly configured helical formation on the other member when the members are inter-engaged, a plurality of locking elements of substantially complementary configuration to the profile of the helical groove and helical formation being receivable between the helical formation and the helical groove on engagement of the male and female members.

2. A coupling means as claimed in claim 1 wherein the helical formation comprises a helical array of apertures.

3. A coupling means as claimed at claim 1 wherein the helical formation is formed as a continuous helical recess terminating short of the end/or ends of the one member.

4. A coupling means as claimed at claim 1 wherein the helical formation comprises a set of groove shaped recesses.

5. A coupling means as claimed at claim 2, 3 or 4 wherein each locking element is shaped as a ball.

6. A coupling means as claimed at any one of claims 2, 3 or 4 wherein the locking element is cubic in shape.

7. A coupling means as claimed at any one of claims 2, 3 or 4 wherein the locking element is substantially cylindrical in shape.

8. A coupling means as claimed at claim 7 wherein the locking elements are receivable in the helical formation such that their central axes are directed radially.

9. A coupling means as claimed at claim 7 wherein the locking elements are receivable in the helical formation such that their central axes are substantially tangential.

10. A coupling means as claimed at any one of the preceding claims wherein a set screw is receivable in the female member to be engagable with one or more locking elements received between the helical groove and the helical formation and the members are substantially fully engaged to clampingly engage the locking element between the male and female members.

11. A coupling means substantially as herein described.