GB2103527A

GB2103527A - Continuous extrusion

Info

Publication number: GB2103527A
Application number: GB08124667A
Authority: GB
Inventors: James Duckworth
Original assignee: UK Atomic Energy Authority
Current assignee: UK Atomic Energy Authority
Priority date: 1981-08-12
Filing date: 1981-08-12
Publication date: 1983-02-23

Abstract

Continuous extrusion apparatus of the kind having a grooved wheel and a fixed shoe has a die set 28 having a chamber the entry 35 to which is larger in cross-section than that of the groove 23 in the wheel 21. A seal is formed between the die set and the wheel by contacting the die entry with the face of the wheel. The die has a stepped portion 34 whereby back pressure is generated to ensure filling of the die. <IMAGE>

Description

SPECIFICATION Improvements in apparatus for the performance of continuous extrusion This invention relates to apparatus for the performance of continuous extrusion of feedstock materials. The materials involved may be metals or alloys, cermets, ceramics, plastics or any other materials which are extrudable. The form of feed of the material may be solid, particulate, including powder, granules, spheroids etc, swarf, turnings, slicings, off-cuts, scrap or any other form capable of being compacted into a form and condition allowing extrusion.

A process and apparatus for continuous extrusion is described in our UK Patent Specification No 1,370,894, particularly the apparatus described with reference to Fig. 3 thereof. Figs. 5-9 thereof show various embodiments of the shoe 4 of Fig. 3; in such Figs. 5-9 various forms of die or dies 6 are shown incorporated in the material of shoe 4.

Our subsequently filed UK Patent Specification No 1,434,201, which is a Patent of Addition to 1,370,894, discloses, in Figs. 1 and 2 thereof, the shoe 4 having a removable insert member 6 secured in the shoe 4, the insert member 6 being made and dimensioned so as to have a portion which projects into the endless groove 3 in the wheel 1 of the extrusion apparatus, the relative position of the insert member 6 within the groove 3 being adjustable in the depth sense.

Our copending UK Application No 80 1 8943 is concerned with a form of die for production of, for example, tubing, by continuous extrusion as aforesaid, and involved with and incorporated in an assembly of shoe member (including a portion which projects into the wheel groove as aforesaid) and abutment, the latter serving to block the endless groove and cause upsetting of the feed material and extrusion through the die means.

The present invention provides an improved die set for use with continuous extrusion apparatus having a grooved wheel with which the die set cooperates such as described in UK Patent Nos 1,370,894 and related to the description above with respect to UK Patent Nos 1,370,894 and 1,434,201, the die set according to the present invention having a chamber the entry to which is larger in cross section than the groove in the wheel and a seal is obtained between the die set and wheel by contacting the die entry with the face of the wheel and the die has a stepped portion providing back pressure to ensure filling of the die.

An embodiment of the invention will now be described with reference to the accompanying drawing in which: Figure 1 shows a die set according to the invention in medial section; Figure 2 shows a view in the direction of the arrow II of Fig. 1; and Figure 3 shows a section on the line Ill-Ill of Fig. 1.

In the drawings there is shown in dash outline an arc of a rotatable wheel 21 with a groove 23, the base of which is represented by the dash line having that reference numeral. The wheel 21 co-operates with a fixed shoe 24 which carries a die set 28.

The die set provides a member 26 which is formed as an insert in shoe 24 and which projects into the groove 23. The member 26 is terminated by an abutment 27, which is also an insert in shoe 24. The abutment 27 extends to the floor of the groove 23 and is backed up by a member 25 and both are carried in a die mounting block 29 secured as an insert in the shoe 24.

The body 29 retains a die 30 which spans the groove 23 so that the die entry 35 has opposed parts which closely contact those parts of the periphery of the wheel 21 which are disposed outside the groove 23 thereof, the entry 35 being larger in cross section than that of the groove 23. The entry 35 lies between the insert member 26 and the abutment 27, that is, as an outlet from the passageway 41 formed by the sides and floor of wheel groove 23 and the underside of member 26. Cooling channels 31 and 32 are provided in body 29. An annular cooling channel 33 exists at the throat of the die 30.

Both cooling channels are supplied and outletted at the exterior of the fixed shoe 24.

The die 30 has a step 34 which provides a back pressure to ensure filling of the die. The outlet 37 of the die is divergent and leads via apertures 38, 39 of increased diameter to the exterior of shoe 24 and to a suitable collection point for extruded product, not shown, for example, spooling means in the case of rod or wire.

Fig. 3 shows the die 30 closely contacting the parts of the face of the wheel 21 which lie outside the groove 23, the die 30 having an entry 35 which is larger in cross-section than the cross-section of the groove of the wheel 21.

In operation, feed material to be extruded, and represented by the arrow 40, is supplied continuously to the passageway 41 and arrives at the abutment 27 which effectively blocks the groove 23. The feed material is upset in the passageway 41 in front of the abutment 27 and enters the die 30 where it experiences extrusion before issuing from the die radially with respect to the wheel 21 via outlets 37, 38 and 39. The wheel 21 is rotated in the direction of the arrow 42, Fig.

1, to perform the extrusion, the shoe 24, insert 26, abutment 27, back-up member 25, and die set 28 remaining stationary.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in apparatus for the performance of continuous extrusion This invention relates to apparatus for the performance of continuous extrusion of feedstock materials. The materials involved may be metals or alloys, cermets, ceramics, plastics or any other materials which are extrudable. The form of feed of the material may be solid, particulate, including powder, granules, spheroids etc, swarf, turnings, slicings, off-cuts, scrap or any other form capable of being compacted into a form and condition allowing extrusion. A process and apparatus for continuous extrusion is described in our UK Patent Specification No 1,370,894, particularly the apparatus described with reference to Fig. 3 thereof. Figs. 5-9 thereof show various embodiments of the shoe 4 of Fig. 3; in such Figs. 5-9 various forms of die or dies 6 are shown incorporated in the material of shoe 4. Our subsequently filed UK Patent Specification No 1,434,201, which is a Patent of Addition to 1,370,894, discloses, in Figs. 1 and 2 thereof, the shoe 4 having a removable insert member 6 secured in the shoe 4, the insert member 6 being made and dimensioned so as to have a portion which projects into the endless groove 3 in the wheel 1 of the extrusion apparatus, the relative position of the insert member 6 within the groove 3 being adjustable in the depth sense. Our copending UK Application No 80 1 8943 is concerned with a form of die for production of, for example, tubing, by continuous extrusion as aforesaid, and involved with and incorporated in an assembly of shoe member (including a portion which projects into the wheel groove as aforesaid) and abutment, the latter serving to block the endless groove and cause upsetting of the feed material and extrusion through the die means. The present invention provides an improved die set for use with continuous extrusion apparatus having a grooved wheel with which the die set cooperates such as described in UK Patent Nos 1,370,894 and related to the description above with respect to UK Patent Nos 1,370,894 and 1,434,201, the die set according to the present invention having a chamber the entry to which is larger in cross section than the groove in the wheel and a seal is obtained between the die set and wheel by contacting the die entry with the face of the wheel and the die has a stepped portion providing back pressure to ensure filling of the die. An embodiment of the invention will now be described with reference to the accompanying drawing in which: Figure 1 shows a die set according to the invention in medial section; Figure 2 shows a view in the direction of the arrow II of Fig. 1; and Figure 3 shows a section on the line Ill-Ill of Fig. 1. In the drawings there is shown in dash outline an arc of a rotatable wheel 21 with a groove 23, the base of which is represented by the dash line having that reference numeral. The wheel 21 co-operates with a fixed shoe 24 which carries a die set 28. The die set provides a member 26 which is formed as an insert in shoe 24 and which projects into the groove 23. The member 26 is terminated by an abutment 27, which is also an insert in shoe 24. The abutment 27 extends to the floor of the groove 23 and is backed up by a member 25 and both are carried in a die mounting block 29 secured as an insert in the shoe 24. The body 29 retains a die 30 which spans the groove 23 so that the die entry 35 has opposed parts which closely contact those parts of the periphery of the wheel 21 which are disposed outside the groove 23 thereof, the entry 35 being larger in cross section than that of the groove 23. The entry 35 lies between the insert member 26 and the abutment 27, that is, as an outlet from the passageway 41 formed by the sides and floor of wheel groove 23 and the underside of member 26. Cooling channels 31 and 32 are provided in body 29. An annular cooling channel 33 exists at the throat of the die 30. Both cooling channels are supplied and outletted at the exterior of the fixed shoe 24. The die 30 has a step 34 which provides a back pressure to ensure filling of the die. The outlet 37 of the die is divergent and leads via apertures 38, 39 of increased diameter to the exterior of shoe 24 and to a suitable collection point for extruded product, not shown, for example, spooling means in the case of rod or wire. Fig. 3 shows the die 30 closely contacting the parts of the face of the wheel 21 which lie outside the groove 23, the die 30 having an entry 35 which is larger in cross-section than the cross-section of the groove of the wheel 21. In operation, feed material to be extruded, and represented by the arrow 40, is supplied continuously to the passageway 41 and arrives at the abutment 27 which effectively blocks the groove 23. The feed material is upset in the passageway 41 in front of the abutment 27 and enters the die 30 where it experiences extrusion before issuing from the die radially with respect to the wheel 21 via outlets 37, 38 and 39. The wheel 21 is rotated in the direction of the arrow 42, Fig. 1, to perform the extrusion, the shoe 24, insert 26, abutment 27, back-up member 25, and die set 28 remaining stationary. CLAIMS

1. An improved die set for use with continuous extrusion apparatus having a grooved wheel with which the die set cooperates and of the kind described in British Patent Specification No 1,370,894 as modified by British Patent Specification No 1,434,201 particularly as described with reference to Figs. 1 and 2 thereof, such die set having a chamber the entry to which is larger in cross-section than that of the groove in the wheel, sealing between the die set and wheel by ensuring contact of the die entry with the face of the wheel, and a stepped portion of the die whereby back pressure is generated to ensure filling of the die.

2. A die set, substantially as hereinbefore described with reference to the accompanying drawings.

3. Continuous extrusion apparatus of the kind specified in Claim 1 and incorporating a die set according to either of claims 1 and 2.