GB1588232A

GB1588232A - Wire-drawing cones

Info

Publication number: GB1588232A
Application number: GB3917076A
Authority: GB
Original assignee: Smiths Group PLC
Current assignee: Smiths Group PLC
Priority date: 1977-09-19
Filing date: 1977-09-19
Publication date: 1981-04-15

Description

(54) WIRE-DRAWING CONES (71) We, SMITHS INDUSTRIES LIMITED, a British Company of Cricklewood, London NW2 6JN, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to wire-drawing cones.

According to one aspect of the present invention, there is provided a wire-drawing cone comprising a tubular core having a stepped outer surface and which is to be rotated about a longitudinal axis, at least two ceramic annuli supported by the core and disposed around the stepped outer surface of the core coaxially with respect to said axis in echelon with the annuli partially overlapping one another axially of the core, and means mounting the annuli on the core, the means including a part clamped between the annuli which extends completely across the overlying portions of the annuli and which substantially inhibits relative displacement of the annuli and the part.

The said part may be provided with a flange which engages with an outer peripheral surface of one of the ceramic annuli to retain that annulus coaxial with said core. In these circumstances, the said part may be provided with a further flange which engages with an outer peripheral surface of the other annulus to retain that annulus coaxial with the core.

The part may have side surfaces which abut respective side surfaces of the said annuli. The said abutting surfaces of the annuli and the part may be planar surfaces extending transversely of the said axis.

The said part may extend completely between the said overlying portions of the annuli and, in such a case, the said flanges may extend completely around the part.

The said part may be in the form of a disc having an aperture through which the said core extends.

The said part may comprise a substantially rigid member and a pair of deformable members disposed between the rigid member and respective ones of the said annuli. The rigid member may be a unitary member.

The said part may be secured to the core by retaining means, for example screws, and the retaining means may extend into respective axially extending bores in said core.

Preferably, there is an annular gap between the inner peripheral surface of each of said annuli and the said tubular core.

The wire-drawing cone may include a multiplicity of ceramic annuli with a respective said part disposed between each adjacent pair of annuli.

A wire-drawing cone in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an end view of a composite wire-drawing cone; Figure 2 is an enlarged cross-sectional view of the composite wire-drawing cone along the lines Il-Il of Figure 1; and Figure 3 is an enlarged view of a portion of Figure 2 showing, in particular, the outer surface of a ceramic annulus of the composite wire-drawing cone.

A composite wire-drawing cone generally comprises a tubular metal core to be rotated about a longitudinal axis, and a plurality of ceramic annuli mounted coaxially on the core in echelon to provide individual wire-engaging surfaces of the cone.

With reference to Figures 1 and 2 of the accompanying drawings, there is shown a composite wire-drawing cone which includes a tubular metal core 10, of, for example, steel or aluminum, having an axial bore 11 through which a rotatable drive shaft (not shown in the drawings) is to extend, the drive shaft being mechanically coupled to the core 10 to rotate the core 10 about its longitudinal axis.

The bore 11 increases in diameter towards an opening 19 in one end of the core 10. The peripheral surface of the core 10 is stepped and also increases in diameter towards the opening 19 to give the core 10 a generally conical shape. The outer peripheral surface of the core 10 has mounted thereon six ceramic annuli 12 to 17 of substantially rectangular cross-section whose outer peripheral surfaces provide the individual wire-engaging surfaces of the cone.

The six ceramic annuli 12 to 17 are clamped in echelon on the core 10 by seven clamping rings 21 to 26 and 18 such that they extend parallel to one another and such that they are coaxial with the longitudinal axis of the core 10.

The largest diameter ceramic annulus, 17, is clamped between the two clamping rings 26 and 18. The clamping ring 26 is rigidly mounted on the core 10 by means of six machine-screws (not visible in the drawings) which screw into respective bores in the core 10. The clamping ring 18, however, is mounted on a cylindrical surface 35 of the core 10 so as to permit movement of the clamping ring 18 axially of the core 10, but to substantially prohibit radial movement. The ring 18 is secured on the core 10 by means of six machine-screws 20 which can be tightened in order to move the clamping ring 18 axially of the core 10 towards the clamping ring 26, and thereby achieve clamping of the ceramic annulus 17.The screws 20 are spaced at intervals around a circumference of the ring 18 and extend in a direction parallel to the longitudinal axis of the core 10, through the ring 18, a spacing gap 36 and into respective, threaded bores 27 in the core 10.

The next largest ceramic annuli, 16, is clamped between the clamping ring 25 and the rear surface of the clamping ring 26 in a similar manner to that described with reference to the ceramic annulus 17, only in this case the clamping ring 25 is moved in the opposite sense to achieve clamping. The clamping ring 25 is mounted on a cylindrical surface 33 of the core 10 and is secured thereto by means of six screws 37 (only one of which is shown in the drawings) which pass through the ring 25 and a spacing gap 39 into respective threaded bores 38 in the core 10.

The remaining ceramic annuli 12 to 15 are clamped in a manner identical to that described above with reference to the annulus 16 between the clamping rings 21 and 22, 22 and 23, 23 and 24, 24 and 25 respectively.

Each of the annuli 12 to 17 is clamped between substantially flat, radially-extending surfaces on its associated clamping rings, and a thin deformable washer 28 of cotton-based cartridge paper or similar material is disposed between each side of a ceramic annulus and its respective flat surface in order to improve clamping. The washer 28 can be seen more clearly in Figure 3. Each of the clamping rings 21 to 26 and 18 is substantially in the form of a disc having a central aperture therein through which the core 10 extends, and includes an integral flange 40 which extends completely around the ring and engages with the outer peripheral surface of its respective ceramic annulus.Furthermore, the clamping rings 22 to 26 each have a recess 41 in their rear surface in which a side of their adjacent ceramic annulus is received such that a shoulder 42 of each recess 41 engages with the outer peripheral surface of the associated annulus. The flanges 40 and shoulders 42 serve to retain the ceramic annuli 12 to 17 coaxial with the core 10.

An annular gap 45 is provided between the inner peripheral surfaces of each of the ceramic annuli 12 to 17 and the outer peripheral surface of the core 10 to accommodate relative radial movement between the ceramic annuli and the metallic core 10 resulting from thermal expansion which occurs during operation of the wiredrawing cone.

As can be seen from Figure 2 of the drawings, the ceramic annuli 12 to 17 are disposed around the core 10 such that a portion of each annulus overlies a portion of its adjacent annulus in a direction axially of the core 10.

The clamping-rings 22 to 26 situated between the pairs of adjacent annuli 12 and 13, 13 and 14, 14 and 15, 15 and 16, and 16 and 17 respectively, are thereby effectively clamped between the overlying portions of their respective adjacent pair of annuli. It has been found that such an arrangement increases the overall rigidity of the assembly, and substantially prevents twisting of the annuli 12 to 17 and the clamping-rings 22 to 26, especially during operation of the wire-drawing cone.

The frictional forces which exist between the sides of the ceramic annuli 12 to 17, the washers 28, and their associated clamping rings 21 to 26 and 18 are not usually sufficient to ensure satisfactory driving of the ceramic annuli 12 to 17 by the core 10, especially when the wire-drawing cone is being operated at high temperatures. For this reason, driving pins 49 are mounted in respective recesses 50 in the core 10, with each of the pins 49 projecting into a respective slot 51 formed in an associated one of the ceramic annuli 12 to 17.

In operation, the core 10 is made to rotate by engagement with the drive shaft, and the pins 49 abut with walls of the slots 51 thereby to rotate the ceramic annuli 12 to 17 with the core 10. The pins 49 may be formed entirely of steel, or may be of the type having a steel core coated with a resilient plastic material.

As will be seen more clearly from Figure 3 of the accompanying drawings, the outer peripheral surface of each of the ceramic annuli 12 to 17 is flush with the shoulders 40 and 42 and is shaped to define between those shoulders 40 and 42 an annular groove 47 in which the wire to be drawn is confined. The edge portions 46 of the peripheral surface of each annulus extends inwardly from the shoulders 40 and 42 of its associated clamping rings to form a step. Each of the surfaces 48 of the clamping rings 21 to 26 is inclined at an angle oe in the order of 5" to a plane transversely of the rotational axis.

The bottom surface of the groove 47 of each of the ceramic rings 12 to 17 may be conical, rather than cylindrical as shown in Figure 3, and inclined at an angle in the order of 10 to the longitudinal axis of rotation of the cone, such that, in operation, the wire tends to move towards one side of the ceramic ring.

Referring again to Figure 2 of the drawings, the wire-drawing cone is provided with a conically-shaped member 53 comprised entirely of ceramic material which is mounted on one end of the metal core 10 and which provides three additional wire-engaging surfaces 54, 55 and 56. The ceramic member 53 has an axial bore 57 of the same diameter as, and in axial alignment with the bore 11 of the core 10. The aforementioned drive shaft extends through the bores 11 and 57 and has a member (not shown) attached thereto which bears against the face 58 of the member 53 to hold the member 53 in position against the core 10 and the clamping ring 21.The clampingring 21 is recessed at 60 to receive the end face of the member 53 and provides a shoulder 61 to retain the member 53 coaxially on the core 10 in a similar manner to that described with reference to the recesses 41 in the clamping-ring 22 to 26. Thrust-washers 62 and 63 of nitrile rubber or similar material are disposed between the member 53 and the core 10 and clamping-ring 21, and on the surface 58 of the member 53 respectively.

The core 10 is rotatably driven by two drive pins (not shown) which are attached to a member mechanically coupled to the drive shaft and which extend into respective recesses 64 in the core 10. In turn, the core 10 drives the member 53 by a pin (not shown) mounted in the core 10 which extends axially into a recess in the member 53.

The aforementioned clamping rings 21 to 26 are all in the form of unitary rings. However, it is envisaged that each of these clamping rings may comprise a pair of semi-circular parts which, when mounted on the core 10, substantially form a ring. Alternatively, each of the clamping rings 21 to 26 may be replaced by a multiplicity of separate plates spaced at intervals around the core 10. It will be appreciated that each of the multiplicty of plates which replace the clamping rings 22 to 26 are mounted on the core 10 and extend completely across the overlying portions of their respective adjacent pair of ceramic rings.

WHAT WE CLAIM IS: 1. A wire-drawing cone comprising a tubular core having a stepped outer surface and which is to be rotated about a longitudinal axis, at least two ceramic annuli supported by the core and disposed around the stepped outer surface of the core coaxially with respect to said axis in echelon with the annuli partially overlapping one another axially of the core, and means mounting the annuli on the core, the means including a part clamped between the annuli which extends completely across the overlying portions of the annuli and which substantially inhibits relative displacement of the annuli and the part.

2. A wire-drawing cone according to Claim 1, wherein the said part is provided with a flange which engages with an outer peripheral surface of one of the ceramic annuli to retain that annulus coaxial with said core.

3. A wire-drawing cone according to Claim 2, wherein the said part is provided with a further flange which engages with an outer peripheral surface of the other annulus to retain that annulus coaxial with the core.

4. A wire-drawing cone according to any one of the preceding claims, wherein the said part has side surfaces which abut' respective side surfaces of the said annuli.

5. A wire-drawing cone according to Claim 4, wherein the said abutting surfaces of the annuli and the said part are planar surfaces extending transversely of the said axis.

6. A wire-drawing cone according to any one of the preceding claims, wherein the said part extends completely between the said overlying portions of the annuli.

7. A wire-drawing cone according to Claim 6 and Claim 3, wherein the said flanges extend completely around the said part.

8. A wire-drawing cone according to any one of the preceding claims, wherein the said part is in the form of a disc having an aperture through which the said core extends.

9. A wire-drawing cone according to any one of the preceding claims, wherein the said part comprises a substantially rigid member and a pair of deformable members disposed between the rigid member and respective ones of said annuli.

10. A wire-drawing cone according to Claim 9, wherein the rigid member is a unitary member.

11. A wire-drawing cone according to any one of the preceding claims, wherein the said part is secured to the core by retaining means.

12. A wire-drawing cone according to Claim 11, wherein the retaining means comprises screws which extend into respective axially extending bores in said core.

13. A wire-drawing cone according to any one of the preceding claims, wherein an annular gap is provided between the inner peripheral surface of each of said annuli and the said tubular core.

14. A wire-drawing cone according to any one of the preceding claims, including a multiplicity of ceramic annuli with a respective said part disposed between each adjacent pair of annuli.

15. A wire-drawing cone according to any one of the preceding claims, wherein the bore

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. angle oe in the order of 5" to a plane transversely of the rotational axis. The bottom surface of the groove 47 of each of the ceramic rings 12 to 17 may be conical, rather than cylindrical as shown in Figure 3, and inclined at an angle in the order of 10 to the longitudinal axis of rotation of the cone, such that, in operation, the wire tends to move towards one side of the ceramic ring. Referring again to Figure 2 of the drawings, the wire-drawing cone is provided with a conically-shaped member 53 comprised entirely of ceramic material which is mounted on one end of the metal core 10 and which provides three additional wire-engaging surfaces 54, 55 and 56. The ceramic member 53 has an axial bore 57 of the same diameter as, and in axial alignment with the bore 11 of the core 10. The aforementioned drive shaft extends through the bores 11 and 57 and has a member (not shown) attached thereto which bears against the face 58 of the member 53 to hold the member 53 in position against the core 10 and the clamping ring 21.The clampingring 21 is recessed at 60 to receive the end face of the member 53 and provides a shoulder 61 to retain the member 53 coaxially on the core 10 in a similar manner to that described with reference to the recesses 41 in the clamping-ring 22 to 26. Thrust-washers 62 and 63 of nitrile rubber or similar material are disposed between the member 53 and the core 10 and clamping-ring 21, and on the surface 58 of the member 53 respectively. The core 10 is rotatably driven by two drive pins (not shown) which are attached to a member mechanically coupled to the drive shaft and which extend into respective recesses 64 in the core 10. In turn, the core 10 drives the member 53 by a pin (not shown) mounted in the core 10 which extends axially into a recess in the member 53. The aforementioned clamping rings 21 to 26 are all in the form of unitary rings. However, it is envisaged that each of these clamping rings may comprise a pair of semi-circular parts which, when mounted on the core 10, substantially form a ring. Alternatively, each of the clamping rings 21 to 26 may be replaced by a multiplicity of separate plates spaced at intervals around the core 10. It will be appreciated that each of the multiplicty of plates which replace the clamping rings 22 to 26 are mounted on the core 10 and extend completely across the overlying portions of their respective adjacent pair of ceramic rings. WHAT WE CLAIM IS:

1. A wire-drawing cone comprising a tubular core having a stepped outer surface and which is to be rotated about a longitudinal axis, at least two ceramic annuli supported by the core and disposed around the stepped outer surface of the core coaxially with respect to said axis in echelon with the annuli partially overlapping one another axially of the core, and means mounting the annuli on the core, the means including a part clamped between the annuli which extends completely across the overlying portions of the annuli and which substantially inhibits relative displacement of the annuli and the part.

of said tubular core is adapted to receive a drive shaft for rotating said core.

16. A wire-drawing cone substantially as hereinbefore described with reference to the accompanying drawings.