GB2048145A - Lubricating wire in a wire drawing machine - Google Patents

Abstract

A soap box for a wire drawing machine permits easy removal of powdered soap from the path (5) of a wire upstream of a drawing die (4). Soap inlet (18) and outlet (11) ports are provided in a cylindrical container (8) and a movable closure member (16) is located within the container to ensure that in an open position of the member soap powder ingress to the container is prevented while soap in the container flows out through the outlet (11) and in a closed position the soap inlet (18) is open to permit soap to flow into the container. <IMAGE>

Description

SPECIFICATION Improvements in and relating to lubricating wire in a wire drawing machine This invention relates to the drawing of wire through sizing openings and in particular to the means for lubricating the wire upstream of the sizing opening. Powdered lubricants are widely used in the drawing of wires and are normally contained in a soap box located immediately upstream of the sizing opening, commonly defined by a fixed die, so that the wire is drawn through a loose bed of the powdered "soap" as it enters the sizing opening. Since wire is commonly drawn on a multi-stage machine with sizing openings of successively smaller cross-section in succeeding stages of the machine, a plurality of soap boxes are normally provided, and the operator has to monitor the level of the soap in each box and to ensure that soap of satisfactory quality is present in each box.Failure to correctly lubricate the wire in a high speed wire drawing machine will have serious consequences not just resulting in wire breakage (and thus considerable down-time of the machine while rethreading of the wire through the different stages takes place) but frequently expensive damage to one or more of the dies used to define the sizing openings.

With the trend dowards direct water-cooling of wire during wire drawing there is an increased possibility of water getting into a soap box and deleteriously affecting the quality of the soap. It is thus increasingly important to be able to supervise the condition of the soap during a drawing operation. High drawing speeds cause appreciable movement of the soap in the soap box and in the case of very finely divided soap powders can make a proportion of the soap in the soap box airborne to pollute the environment.

This invention relates to an improved form of soap box which can be closed off from the surrounding atmosphere during a drawing operation and which ensures periodic emptying and refilling of the soap box and in turn reduces the possibility of an unnoticed deterioration in the quality of the soap in a box, or an unnoticed danagerous drop in the level of the bed of soap in a box.

According to the present invention a soap box in a wire drawing machine comprises a container having an access port, aligned wire-inlet and wire-outlet openings and a closure member for obturating the access port in its closed position and exposing the port in its open position and is characterised in that when the closure member is in its open position, an inlet passage for a soap supply to the box is closed and an outlet passage for soap from the box is open, and in that when the closure member is in its closed position, the inlet passage for soap is open.

The outlet passage for soap can be closed in the closed position of the closure member, but where a continuous circulation of soap through the box is to be used during drawing, the degree of opening of the outlet soap passage may merely be reduced when the closure member is in its closed position.

Suitably the soap outlet passage is located in the lowest part of the soap box to permit powdered soap to flow by gravity from the box.

By respectively closing and opening the soap inlet and outlet passages when the access port is exposed, it is possible to ensure that the soap level in the box drops when the port is exposed thus facilitating threading-up when the soap level falls below the axis of the wire-inlet and wire-outlet openings.

The closure member can be interlocked to the machine controls to ensure that high speed drawing can only occur when the closure member is in its closed position and the soap level in the box has risen to a level above the aligned axes of the wire openings.

Rather than rely on drawing the wire through a substantially stationary bed of powdered soap, the bed can be fluidised and to achieve this an air distribution chamber with spaced-apart air openings can be provided in the bottom of the container. Electrostatic precipitation of soap onto the wire can be employed as an alternative to a stationary bed of powder or a fluidised bed of powder. This possibility is discussed in an article by James Miller (Wire Journal, October 1978, 7477) entitled "The electrostatic application of dry powdered lubricants in wiredrawing".By making the container of an electrically insulating material (e.g. a plastics material) and injecting the soap into the container in such wise that the particles become highly charged electrically, the soap particles will be drawn to the wire (which is at earth potential) and will be adhered thereto as the wire moves into the die. Electrostatic lubricant coating in a soap box in accordance with this invention may enable the use of input feedstock wire to the first die of a multi-die machine without conventional treating or pre-coating and sould enable the use of water-soluble soaps (e.g.

sodium-based lubricants) in a multi-die machine which is cooling the wire between die passes by direct water contact.

The invention has application to any conventional wiredrawing machine but is thought to be of particular utility in connection with the wire drawing apparatus and method disclosed in the descriptions filed with our co-pending UK Patent Applications 7848053, 7903285 and 7915881.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a sectional side elevation of a soap box in accordance with the invention shown in the closed condition, Figure 2 is a sectional view of the box of Figure 1 shown on the line Il-Il, Figure 3 is a simplified section on the line lll-lV of Figure 1 also showing the box in its closed condition, and Figure 4 is a view corresponding to Figure 3, but showing the box in its open condition.

The soap box shown in Figure 1 comprises a cylindrical container 1 interposed between a guide die assembly 2 and a main die assembly 3 which contains a die 4 providing the sizing opening for wire to be drawn. The wire path is shown by the horizontal chain line 5 and the wire passes from left to right through the container 1.

The container 1 is constructed from spacedapart end plates 6 and 7 to which is welded an outer cylindrical sleeve 8. The sleeve 8 is provided with an access port 9, an inlet passage 10 for soap and an outlet passage 11 for soap. The outlet passage 11 is located in the lowest part of the container and acts to lead soap flowing out of the container 1 into a return pipe 12 (see Figure 2).

The pipe 1 2 leads to a soap reservoir (not shown) in which soap powder can be treated to maintain its quality and from which reservoir leads a supply pipe 13 which communicates with the inlet passage 1 0. A single reservoir can be used for a plurality of soap boxes. Wire-inlet and outlet openings are provided in the end plates and are marked by 14 and 15, respectively, in the drawings.

Surrounded by the sleeve 8 is a turnable inner sleeve 1 6 which also exhibits an access port 1 7 and inlet and outlet passages 18 and 19, respectively. An operating handle 20 is attached to the sleeve 1 6 and rides in a slot 21 formed in the sleeve 8 and subtending an arc of about 1 40C at the axis of sleeve 8. The handle 20 is shown in Figures 1,2 and 3 in one limit position which leaves the access ports 9 and 1 7 out of register (ie closes the container 1), aligns the passages 10 and 18 and closes the passage 11. With the handle in this position soap powder can flow down the pipe 1 3 (with or without pressurisation) to form a bed in the container which rises above the level of the line 5. A possible outline of the bed is shown by the dotted lines 22.

When a drawing run has been completed, the handle 20 is moved in the slot 21 to the position shown in Figure 4 with the consequence that the ports 9 and 1 7 are substantially coincident, the passage 10 is closed and the passage 11 is aligned with the passage 1 9. In this condition the soap which formed the bed in the container will flow out through the pipe 12 (while further inflow of soap will be prevented) and the container is opened to allow an operator access to its interior for any manual tasks associated with a threadingup operation.

If electrostatic precipitation is to be employed, a suitable powder injector nozzle can be located in place of the pipe 13 to blow charged particles of powder at the earthed wire extending between the plates 6 and 7. Voltages up to 90kV can be employed for charging the particles and the electrostatic forces between the charged insulating particles of dry lubricant and the wire hold the particles against the wire as the latter enters the die 4 making it possible to dispense with the carrier coating of lime, borax or phosphate commonly applied to inputfeedstock wire. The electrostatic forces can also be employed to hold dry water-soluble lubricant powders to the wire so that the removal of the lubricant coating used at an upstream stage by direct water cooling of the wire at that stage does not prevent a fresh coating being applied to the bare wire prior to its being drawn at the succeeding stage.

Claims (8)

1. A soap box in a wire drawing machine comprising a container having an access port, aligned wire-inlet and wire-outlet openings and a closure member for obturating the access port in its closed position and exposing the port in its open position is characterised in that when the closure member is in its open position, an inlet passage for a soap supply to the box is closed and an outlet passage for soap from the box is open, and in that when the closure member is in its closed position, the inlet passage for the soap is open.

2. A soap box as claimed in claim 1, in which the outlet passage for soap is closed in the closed position of the closure member.

3. A soap box as claimed in claim 1, in which the degree of opening of the outlet soap passage is merely reduced when the closure member is in its closed position.

4. A soap box as claimed in any preceding claim, in which the soap outlet passage is located in the lowest part of the soap box to permit powdered soap to flow by gravity from the box.

5. A soap box as claimed in any preceding claim, in which the closure member is interlocked to the controls of the drawing machine to ensure that high speed drawing can only occur when the closure member is in its closed position and the soap level in the box has risen to a level above the aligned axes of the wire openings.

6. A soap box as claimed in any preceding claim, in which an air distribution chamber with spaced-apart air openings is provided in the bottom of the container to permit a bed of powdered soap in the container to be fluidised.

7. A soap box as claimed in claim 1, in which the container is made of electrically insulating material and means is provided to inject the soap into the container in such wise that the particles become electrically charged.

8. A soap box substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.