EP2794139B1

EP2794139B1 - Lubrication container for wire drawing

Info

Publication number: EP2794139B1
Application number: EP11851626.9A
Authority: EP
Inventors: Alan BUYS; Clifford Roy Warner; Mervyn Neil SPENCER
Original assignee: Cre 8 Tech Ltd; Cre 8 Technologies Ltd
Current assignee: Cre 8 Tech Ltd; Cre 8 Technologies Ltd
Priority date: 2010-12-24
Filing date: 2011-12-22
Publication date: 2019-05-15
Anticipated expiration: 2031-12-22
Also published as: WO2012085885A1; KR20140116129A; CN104066525A; EP2794139A4; EP2794139A1; AU2011346548A1; CN104066525B; AU2011346548B2; KR101958422B1

Description

FIELD OF THE INVENTION

The present invention relates to an apparatus for lubricating metal objects being drawn. In particular, the present invention relates to a dry lubrication apparatus for use with a wire drawing process.

BACKGROUND OF THE INVENTION

Wire drawing is a metal working process used to reduce the diameter of a wire or a rod by pulling the wire or rod through a single or series of drawing dies. A number of different types of die may be used to reduce the diameter of the wire by drawing it through the die. Rotating dies and linear dies can be used depending on the wire drawing process. Lubrication in the drawing process is essential for maintaining a good surface finish and long die life. A variety of lubrication processes are known, such as:

1. wet drawing - the wire or rod being completely immersed in a liquid lubricant,
2. dry drawing - passing a wire or rod through a container of dry lubricant which coats the surface of the wire or rod,
3. metal coating - the wire or rod is coated with a soft meal which acts as a solid lubricant, and
4. ultrasonic vibration - the dies and the mandrels being vibrated, which help to reduce forces and allow larger reductions of wire per pass.

Dry drawing generally involves the use of a powdered lubricant known as "soap" provided in a lubrication container. The wire is pulled through the lubrication container and then through the drawing die. The wire is coated with the lubricant both as it is pulled through the lubrication container, and as it traverses the die. As the drawing process continues, the dry lubricant can become contaminated and performance can reduce. A problem with known lubrication containers is that the lubricant does not get thoroughly mixed and the wire is not always exposed to fresh (meaning undeteriorated) lubricant. This can be particularly bad where a higher concentration of contaminants build up in one area (eg: immediately before the wire enters the die).
In order to address this problem, rotating lubrication containers have been used. These are used to move the soap around within the chamber to mix it, and may also include vanes or baffles to improve mixing. For example, US 7,150,169 discloses a rotating lubrication container for dry drawing. The lubrication container is rotated to agitate the dry lubricant and prevent deteriorated lubricants from accumulating around the drawing die. The lubrication container may also have protrusions that pulverise solidified lubricants as the container rotates. This leads to smaller particle size of the lubricant which can tend to perform better.
EP 0420096 , which forms the basis for the preamble of claim 1, discloses a rotating lubrication container for lubricating metallic rods. The container includes a length wise vane to stir the lubricant powder within the container as the container rotates.
US 2,703,550 discloses a rotating lubrication chamber that has agitator elements or baffles and outwardly flared wall portions to prevent the powdered lubricant from accumulating at the inlets and outlets.
One possible disadvantage to the drawing process and the quality of lubrication achieved, is the collection of contaminated or used lubricant at the exit of the lubrication container. As a wire is drawn through the die the lubricant is exposed to high pressure and deteriorates into solidified chunks. These solid lumps can prevent a consistent supply of lubricant to the wire or rod. Prior art devices with pulverisers tend to pulverise this deteriorated lubricant back into powdered form. However, the deteriorated lubricant remains at the exit of the lubrication container (ie: entry to the die). Even in its finely powdered state due to pulverisation the deteriorated lubricant cannot provide the same degree or quality of lubrication as provided by virgin lubricant. As a result the lubricant must be changed more regularly or removed from the drawing line and purified.
It is an object of the present invention to provide a lubrication container that goes some way to overcome at least one of the disadvantages in the prior art or to at least provide the public with a useful alternative.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

STATEMENTS OF INVENTION

In one aspect the invention can be said to broadly consist of a lubrication container for use in wire drawing, the lubrication container comprising:

a hollow drum for holding lubricant, the drum being rotatable about an axis,
a wire inlet in an inlet end wall of the drum for receiving a wire into the drum,
a wire outlet in an outlet end wall of the drum for conveying the wire from the drum,
a channel arranged about the sidewall of the drum, and tracing a substantially helical path, and
defining a hollow passage,
an inlet aperture in the channel, opening into the hollow drum interior near the outlet end wall of the drum,
an outlet aperture in the channel, opening into the hollow drum interior near the inlet end wall of the drum.

The drum may be substantially cylindrical.
The drum may be a substantially frustro-conical shape.
The lubrication container may further comprise:

an outer drum, surrounding the drum and forming a space therebetween, the outer drum and the drum being co-axially aligned, and rotatable,
the channel being disposed in the space between the outer drum and the drum.

The channel may be formed on the outer surface of the drum.
The channel may be formed on the inner surface of the drum.
The pitch of said channel may result in said channel being angled between 0° to 40° relative to a vertical axis.
The pitch of said channel may result in said channel being angled between 0° to 20° relative to a vertical axis.
The pitch of said channel may result in said channel being angled between 0° to 10° relative to a vertical axis.
The channel may be between 5mm and 40mm in width.
The channel may be less than 35mm in height.
The drum may rotate about a horizontal axis.
The longitudinal axis of the drum may be angled less than 20° to a horizontal axis.
The longitudinal axis of the drum may be angled between 5° and 15° to the horizontal axis.
The longitudinal axis of the drum may be approximately 10° to the horizontal axis.
The channel may comprise:

a plurality of inlet apertures,
a plurality of outlet apertures.

The drum may comprise:
a plurality of channels formed about the drum, in a multiple helical arrangement.
The drum may further comprise:

an opening in the drum, the opening allowing lubricant into the drum,
a removable lid that can be placed over the opening to close the opening and substantially seal the drum.

The drum may be rotated by a drive system that is any one of:

a) a belt drive,
b) a chain drive,
c) a direct drive, or
d) a gear drive

The drive system may rotate the drum at less than 10rpm.
The drive system may rotate the drum at between 2rpm to 5rpm.
The outlet end of the drum may be positioned near to a die during a wire drawing process.
The inlet aperture of the channel may be out of phase with the outlet aperture of the channel.
The inlet aperture of the channel may be in phase with the outlet aperture of the channel.
The channel may trace between half a revolution of the drum and five revolutions of the drum.
The channel may trace one or two revolutions of the drum.
The channel may trace one revolution of the drum.
The drum may further comprise any one or more of:

a) at least one pulveriser,
b) at least one baffle,
c) at least one vane, or
d) at least one stirrer

The channel may be angled relative to the vertical angle, in manner to allow some of the lubricant to enter the channel through the inlet of the channel and travel along the channel toward the outlet of the channel as the drum rotates.
The channel may trace less than two revolutions and at least half a revolution around the drum perimeter.
According to another aspect the invention broadly comprises a method of lubricating wire in a wire drawing process comprising a lubrication container according to any one of the previous clauses, wherein in use, while rotating, the lubricant enters the channel from the drum through the inlet aperture in the channel and the lubricant exits the channel into the drum through the outlet aperture in the channel, the lubricant travels along the channel due to the rotation of the drum.
The lubricant may be constantly mixed due to the rotation of the drum.
The lubricant may be constantly moved from one end of the drum to the other end of the drum, such that a more even concentration of virgin lubricant and fine particles is achieved.
The channel may transport a parcel of lubricant away from the outlet end and to the inlet end as the drum rotates, the parcel of the lubricant moving along the channel as the drum rotates.
The lubricant may enter the channel when the channel inlet is near the bottom of the drum and exit the channel when the channel outlet is at the top of the drum, the channel inlet and outlet moving between the bottom of the drum and top of the drum as the drum rotates.
The lubricant may be re-circulated around the drum due to the movement of lubricant by the channel and by the rotation of the drum.
The drum may be rotated at a speed to facilitate movement of lubricant from the inlet of the channel to the outlet of the channel, the drum also rotated at a sufficient speed to cause mixing of the lubricant within the drum.
The term "comprising" as used in this specification means "consisting at least in part of". When interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner.
The invention consists in the foregoing and also envisages constructions of which the following gives examples only.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a side view of a wire drawing system including a die, lubrication container and housing for the lubrication container,
Figure 2 shows a perspective view of the wire drawing apparatus of Figure 1
Figure 3 shows another perspective view of the wire drawing system of Figures 1 and 2.
Figure 4 shows a cutaway view of the lubrication container shown in Figure 1
Figure 5a is a schematic side view showing the path of the lubricant channel on the lubrication chamber.
Figure 5b is a schematic side view of an alternative embodiment showing the path of the lubricant channel on the lubrication chamber.
Figure 6a is a schematic view illustrating the position of the lubrication channel with respect to the inner and outer walls of the rotating lubrication container.
Figure 6b is a schematic view of the lubrication channel positioned about the inside of a single walled lubrication container.
Figure 6c is a schematic view of the lubrication channel positioned about the outside of a single walled lubrication container.
Figure 6d is a schematic view illustrating the relative position of lubrication channel 205 with respect to the container wall, positioned part way between the wall location.

DETAILED DESCRIPTION

The preferred embodiment will now be described with respect to the figures.

Wire drawing system

The present invention relates to a lubrication container for wire drawing. Figures 1 to 4 show a generic wire drawing system 1. It will be appreciated that the present invention will be useful in many types of wire drawing systems.
The system 1 includes a lubrication container 2 and a die 3. The lubrication container 2 is positioned within a housing 4. The housing 4 includes two supports 5, 6 to retain the lubrication container in the housing 4. Each support structure 5, 6 includes a bearing(s) 7 in the support structure. The bearing(s) allow the lubrication container 2 to rotate freely within the supports about its axis.
The housing 4 also includes a drive system 8 to rotate the lubrication container 2 within the housing. In the preferred form the drive system (not shown) includes a belt that is wrapped around two pulleys, a container pulley and a drive pulley. The container pulley is positioned near the support 5. The belt is preferably a timing belt with a plurality of teeth. Alternatively any other suitable drive system, for example a chain drive, gear drive or a linear direct drive motor system can be used to rotate the lubrication container 2.
The housing 4 includes a wire entrance opening 9 at one end of the housing that receives a metal wire or rod, and a wire exit opening 10 at the other end of the housing; the wire exit 10 passes the wire out into the die 3. The wire entrance 9 and the wire exit 10 are longitudinally opposed and are located at opposite ends of the housing 4. The wire entrance opening 9 and wire exit opening 10 are preferably aligned along a common longitudinal axis A.
The die 3 is preferably longitudinally aligned (co-axial) with the wire exit opening 10 and receives lubricated wire for drawing through the die 3 from the wire exit opening 10. The wire is lubricated in the lubrication container 2 as it passes through the powdered lubricant within. The die 3 is dependent on the particular type of drawing process that is being performed, and can be any suitable die for drawing wire.
In one preferred form, the die 3 is a rotating die for rotational drawing. The die 3 preferably rotates about axis A.
Alternatively any other pressure die or other suitable die can be used.

Lubrication container

Preferred embodiment

The preferred embodiment of the lubrication container 2 will now be described in greater detail particularly with respect to Figure 4. The lubrication container 2 comprises a double skinned drum. The double skinned drum comprises an inner drum 200 and an outer drum 210. The inner and outer drums are preferably co-axially aligned along the longitudinal axis A. The inner and outer drums (200,210) are preferably substantially cylindrical in shape. Alternatively, the inner and outer drums may be a truncated cone shape so that the drum walls are at an angle to the axis of rotation (rather than parallel).
The internal diameter of the inner drum 200 is preferably between 10cm and 70cm and most preferably between 20cm and 30cm. The inner and outer drums are mounted such that they are not angled and their longitudinal axis A is substantially parallel to the horizontal.
There is a sealed space 208 between the inner and outer drums. The space 208 is sealed such that no lubricant from the space 209 falls into or enters the space 208 while the drums 200, 210 are rotating in use. The space 208 is preferably between 5mm and 40mm. The space 208 is defined by the surfaces of the inner drum 200 and outer drum 210.
The inner and outer drums 200, 210 include an opening 400 to fill the inner drum 200 with lubricant. The opening 400 is shown in Figure 4 extends through the outer drum 210 to the inner drum 200. A removable lid 401 is provided to close the opening and seal the contents of the inner drum. The lid is preferably formed to conform substantially to the shape of the opening 400 so that a sealed closure is formed.
The inner and outer drums include an inlet end wall 201 and an outlet end wall 202. The inlet end wall 201 and outlet end wall 202 are preferably common for the inner and outer drums 200, 210, as seen from Figure 4. A wire inlet opening 203 is formed in the inlet end wall 201 and a wire outlet opening 204 is formed in the outlet end 202 wall. The wire inlet opening 203 and the wire outlet opening 204 are longitudinally opposed to each other and are preferably co-axially aligned along the longitudinal axis A of the inner drum 200 and outer drum 210. The inlet opening 203 and the outlet opening 204 are also axially aligned with the wire entrance opening 9 and the wire exit opening 10 of the housing and with the die 3. The openings are all aligned along axis A to ensure the wire is not bent as it passes in to the housing, through the lubrication container 2 and into the die 3.
Figure 4 shows a wire 211 in the inner drum 200, as the wire 211 is pulled through the lubrication container in a drawing process. Preferably both the inner and outer drums are rotated in use by the drive mechanism 8. In one embodiment, the drive mechanism 8 preferably acts on the outer drum 210 and rotates the outer drum in use. The inner drum 200 also rotates with the outer drum 210 because they are attached to each other by their common end walls.
The lubrication container 2 further comprises a channel or passage 205 arranged about the side wall of the lubrication container 2. In one embodiment the channel 205 is formed or disposed within the space 208 between the inner and outer drum, shown in Figure 4 as hidden detail. The channel 205 preferably traces a spiral or helical path around the perimeter or outer surface of the inner drum 200 about the longitudinal axis A.
The channel 205 forms a sealed pathway between its ends within the space 208. In the preferred embodiment, shown in Figure 4, the channel 205 is formed by drums 200,210 and two walls 300, 301 that extend between the inner and outer drum surfaces, in the space 208, to form a sealed pathway along the length of the spiral. The walls 300, 301 forming the channel trace a spiral or helical path around the outer surface of the inner drum 200 and about the longitudinal axis A. The spiral pitch of channel 205 is preferably constant.
Alternatively, the pitch may vary along the length of the channel.
According to one embodiment the channel traces a path that is half a revolution about the longitudinal axis, as seen in Figure 4.
Alternatively the channel may complete anywhere between half and five revolutions (or spirals) about the axis A. For example an alternative (most preferred) embodiment tracing one complete revolution is schematically illustrated in Figure 5b.
The channel 205 includes an outlet aperture 206 at one end of the channel and an inlet aperture 207 at the other end channel. This is shown in Figure 4, where the outlet aperture 206 is nearer the wire inlet opening 203 and inlet end wall 201 of the inner and outer drums, while the inlet aperture 207 is nearer the wire outlet opening 204 and outlet end wall 202 of the inner and outer drums.
The outlet aperture 206 and the inlet aperture 207 are preferably diametrically opposed to each other such that they are positioned out of phase with each other as the inner drum 200 and outer drum 210 rotate about axis A.
Preferably the channel 205 traces a minimum of half a revolution of the drum.
In an alternative embodiment, the channel 205 traces a minimum of one complete revolution of the drum.
The outlet aperture 206 and the inlet aperture 207 are preferably 180⁰ out of phase as the inner and outer drums rotate about axis A.
Alternatively the outlet aperture 206 and inlet aperture 207 may be aligned or out of phase by any angle between 0 and 360 degrees. In other forms the channel 205 may comprise a plurality of inlet apertures and outlet apertures, each at respective ends of channel 205. Further alternative embodiments may comprise multiple channels arranged in a multiple helix or spiral arrangement spaced around the perimeter of the container 2.
With reference to Figure 5, some important characteristics of channel 205 will be described in more detail. Figure 5 is a schematic side view showing an example of the profile of channel 205 when viewed from the side. As shown, the channel 205 traces a path that is fairly steep in a central zone. It will be appreciated that this central zone 305 will be located on the side of the lubrication container when the container is in the position illustrated and is related to the pitch of the spiral. The passage 205 is at its maximum steepness with respect to vertical axis B illustrated by angle 306. For embodiments where the pitch of spiral passage 205 varies, it is important that the passage is steep in the central zone. ie. In the zone located on the side of the container, so lubricant can flow.
It is important that the nature of the spiral path that passage 205 traces around the lubrication container, is such that there exists one or more zones sufficiently steep for powdered lubricant to flow along the passage as the container rotates.
It has been found that when angle 306 is in the range of approximately 0 and 30 degrees, the container performs well. More preferably, an angle 306 between 0 and 10 degrees works very well.
It will be appreciated that the steepness of angle 306 (ie tending towards 0) will encourage the powdered lubricant to fall under the influence of gravity more effectively. The geometry of the spiral path that passage 205 takes around the container 2 can be optimized with the dimensions of the container in order to make sure the powder 'sees' a sufficiently steep angle at the appropriate position on the circumference of the drum during rotation. It will be appreciated that Figure 5 is a 2 dimensional simplification of the 3 dimensional path that the spiral channel 205 actually takes.
The inner drum 200 defines a space 209 to hold lubricant or soap (not shown) used for wire drawing operations. The lubricant can be any suitable powdered or granulated or pellitized lubricant used for wire drawing operations, for example sodium sterate. The drum is preferably filled with enough lubricant such that the wire travelling through the drum is completely surrounded by lubricant as it passes through the drum. The minimum fill level of lubricant is at least half the volume of the drum 200. Preferably the drum is filled enough to surround the wire while maintaining a small gap between the top surface of the drum so as to allow lubricant from the channel 205 to drop into the drum.
The inner and outer drums are rotated to constantly redistribute the lubricant in the inner drum 200. The channel 205 operates to transport some of the lubricant from near the wire outlet 204 to near the wire inlet opening 203, and preferably has a smooth inner surface. Operation of the container will now be described in more detail. As the inner and outer drums rotate (in direction of arrow), the inlet aperture 207 rotates and arrives at the bottom of the inner drum 200 containing lubricant as illustrated in Figure 4. As the inlet aperture 207 approaches the bottom of the inner drum 200, some of the lubricant (soap) within the inner drum drops into the channel 205 through the inlet aperture 207.
As the drum rotates further, the lubricant in the channel 205 is blocked from flowing back into the inner drum 200, resulting in it being passed along the channel 205 and moved (in the direction of arrow 302) from near the wire outlet opening 204 toward the wire inlet opening 203. That is, the parcel is lifted up the sidewall of the container. The lubricant travels along the channel 205 through a number of revolutions of the drum (depending on the pitch of helix that the channel follows). Eventually the lubricant arrives at the outlet aperture 206 of the channel 205, and the lubricant drops out of the outlet aperture 206, when the outlet aperture 206 is at (or near) the top of the inner drum 200 (during a rotation cycle). "Top" as used in the description means the part of the drum that is further away from the base of the housing. Bottom as used in the description means the part of the drum that is closest to the base of the housing. It will be appreciated that the direction of container rotation with respect to the helix direction is important. If rotated in the opposite direction the parcels of lubricant will not be lifted up the sidewall of the drum, and will not flow along the passage.
Since the inner and outer drums 200, 210 are constantly rotating the channel 205 collects a "parcel" of lubricant on every revolution and transports the parcel along the channel 205. The amount of lubricant collected at every revolution is referred to as a parcel because only a discrete quantity of lubricant drops into the channel 205 when the inlet aperture 207 is at (or near) the bottom of the drum 200. A new "parcel" enters channel 205 every time the inlet aperture is immersed in lubricant as it arrives at the bottom of the container. The parcel of lubricant is shifted along the channel 205 due to the angle of the channel 205 and the rotation of the drum 200. At any one time, the channel may contain several "parcels" of lubricant. As the container rotates the parcels may spread out and even join adjacent parcels.
These discrete parcels are transported along the channel 205 as the inner and outer drums rotate, via the force of gravity acting on the lubricant to move it along channel 205. In particular, the way in which a parcel is delivered into the channel on each rotation, results in the channel being only partially filled with powdered lubricant. This helps move the powdered lubricant along the channel. In this way, the parcel of lubricant is shifted along the channel 205 from one end of the drum and deposited at the other end of the drum.
In the preferred embodiment, it takes approximately four revolutions to move one parcel of soap from the wire outlet opening 204 to the wire inlet opening 203. It is to be understood that each parcel may be spaced along the length of the channel during rotation of the drum or may spread out and merge with neighbouring parcels as progress along the channel continues.
The inner and outer drums 200, 210 are preferably rotated at approximately 2RPM. However, the drum may be rotated at any suitable speed from 1RPM to 30RPM depending on the size of the drum. It has been found that a slower speed is more suitable and therefore the preferred rotational velocity range of the drum 200 is between 2RPM to 6RPM. The soap (lubricant) is more effectively transported along the channel 205 at slower drum rotational speeds. At higher speeds the centripetal forces, due to the rotation of the inner and outer drums, causes the lubricant in the channel 205 to stick to walls of the channel and hence there is no movement of lubricant.
The slower rotation speed of drum 200 causes packets or parcels of lubricant to be transported along the channel 205. As the inner and outer drums 200, 210 rotate each discrete point in the channel moves upward. As the point in the channel moves upward the lubricant at that point is dropped downward and along the channel 205, due to gravity and due to the constant rotation of the channel 205. Due to the backflow prevention characteristics of the entry aperture, an overall forward motion of the packets or parcels is achieved.
The inner drum 200 is constantly rotated to achieve mixing and redistribution of the lubricant within the inner drum 200. Additional vanes, agitators, or stirrers (or pulverisers) may also be employed inside the inner drum if desired. The constant mixing and redistribution of the lubricant due to rotation of the drums is advantageous because the wire drawn through the drum 200 is exposed to relatively fresh lubricant and the wire is not always drawn through the same lubricant. This leads to better lubrication of the wire since the wire is not exposed to old "used" lubricant constantly. The inventors have found that the invention lubricates better and achieves a higher amount of lubrication of the wire and a more consistent coating weight, as the wire is drawn through the inner drum 200. The higher lubrication allows for better performance during the drawing process.
The channel 205 is advantageous because it creates a redistribution of the lubricant within the drum 200. The channel re-distributes contaminated or deteriorated lubricant around the drum in order to dilute content of contaminated lubricant or deteriorated lubricant near the wire outlet opening 204. The level of redistribution resulting from the present invention is extremely difficult (if not impossible) to achieve with simple rotating methods. The contaminated or deteriorated lubricant does not accumulate near the wire outlet 204 because it is continually taken from the die end, transported away, and deposited at the other end by the channel 205.
The channel 205 further acts to move and disperse lubricant through the drum so that a more uniform distribution of virgin lubricant is achieved throughout the inner drum 200. This is advantageous because the wire is exposed to undeteriorated lubricant as it is being drawn through the drum 200 and the lubricant within the drum does not need to be replaced or replenished as often.
The channel 205 transports concentrated fine lubricant from the wire outlet end 202 to the wire inlet end 201. This is advantageous because fine lubricant powder is dispersed more uniformly throughout the inner drum 200 resulting in more consistent particle size distribution throughout the drum 200. The dispersion of fine particles and the control of fine particle concentration due to the channel 205 and rotation of the drum 200 also contributes to reduction in lubricant waste generation. The lubricant is continually shifted along the channel and along the lubrication chamber. This is advantageous because deteriorated lubricant is transported from one end of the drum 200 to the other, hence allowing virgin lubricant to take the place of the shifted deteriorated lubricant.
The lubrication chamber 2 may be formed from any suitable process such as machining, lathing, casting, welding several parts together etc. The lubrication chamber may be formed from any suitable metal such as stainless steel, steel or aluminium. The lubrication container may be made of a polymer material such as a plastic or Perspex. Most preferably the lubrication container is made from a shatter proof material such as a poly-carbonate material. The inner drum 200 and outer drum 210 may be manufactured by any suitable means. As material any suitable metal such as aluminium, steel, stainless steel etc may be used to form the inner drum 200 and outer drum 210. The inner and outer drums may be formed from a polymer material such as plastic or Perspex, but are most preferably formed from a shatter material such as a poly-carbonate. As a further alternative the inner drum 200 and outer drum 210 may be cast.
In an alternative the inner and outer drums 200, 210 (i.e. the lubrication container 2) are mounted within the housing such that the inner and outer drums are inclined at an angle to horizontal line C (shown in figure 1). The longitudinal axis A of the inner and outer drums is angled less than 20°, but preferably between 5° to 15° relative to the horizontal line C (i.e. the horizontal). Preferably the drums are angled such that wire inlet opening 203 is higher than the wire outlet opening 204. In a further alternative the drum may be angled such that the wire outlet opening 204 maybe higher than the wire inlet opening 203.
It will be appreciated, that embodiments including an inclined drum, will have the angle of attack of the channel(s) adjusted accordingly so that lubricant travels along the channel due to gravity accordingly. There are many factors that influence progress of lubricant along the channel(s) such as;

Drum (inner) diameter
Rotation speed of the drum
Angle of attack of the channel (i.e. pitch angle) relative to vertical (i.e. gravity force exerted on lubricant)
Roughness of channel interior surfaces
Lubricant properties

These factors can all be adjusted/optimised for various configurations depending on the specific application and wire drawing line to which the present invention is installed.

Alternative embodiment

In alternate embodiments the lubrication chamber 2 may comprise a single skinned hollow drum as illustrated in Figures 6 b-d.
The drum is preferably cylindrical but can be any other suitable shape such as a truncated cone or elliptical. The drum includes a two end walls, an inlet end wall and an outlet end wall. A wire inlet opening is formed in the inlet end wall and a wire outlet opening is formed in the outlet end wall. The wire inlet opening receives a wire into the drum during a wire drawing operation. The wire is passed through the drum and out through the wire outlet opening to the die positioned at the exit of the wire outlet opening.
The drum is hollow and is adapted to hold powdered lubricant such as sodium sterate. The drum is rotatable about its longitudinal axis (A). The drum may be angled similar to the inner and outer drums as described earlier. The drum is rotated at the same or similar operating speeds as described earlier.
The drum includes an opening in the drum that allows a person to fill the drum with lubricant. The opening is closable with a lid.
In this alternative embodiment the channel is similar to the channel 205 described earlier. However, in this alternative embodiment the channel is preferably formed on and is positioned "proud" of the outer surface of the drum by two walls (300,301) as described in Figure 6c. In this alternative embodiment the channel is closed by a top wall extending the length of the channel. The channel traces a spiral or helical path around the outer surface of the drum and about the drum's longitudinal axis. The channel transports lubricant from the wire outlet of the drum toward the wire inlet of the drum in the same manner as described earlier.
While it is most preferred that the channel 205 is positioned 'outside' of the inner surface of container 2, alternative embodiments are also possible.
For example, the channel 205 may be arranged about the drum standing out from the interior surface (see Figure 6b), or alternatively still arranged part way between the drum skin walls (see Figure 6d).

Further preferred features

The lubricant may be constantly moved from one end to the other end resulting in improved particle size control.
The channel may be angled at approximately 5⁰ to a vertical axis.
The channel may be greater than 5mm in width.
The channel may be between 10mm and 30mm in width.
The channel may be between 5mm and 25mm in height
The channel may be between 5mm and 15mm in height.
The longitudinal axis of the drum may be angled less than 15⁰ to the horizontal axis.
The drive system may rotate the drum at less than 40rpm.
The drive system may rotate the drum at less than 25rpm.
The lubricant may be either a powdered lubricant or a granulated lubricant or a pellitized lubricant.
The channel may trace less than five revolutions around the drum perimeter.
The channel may trace less than two revolutions around the drum perimeter.

Claims

A lubrication container (2) for use in wire drawing, the lubrication container comprising:
a hollow drum (200) for holding lubricant, the drum being rotatable about an axis,

a wire inlet (203) in an inlet end wall (201) of the drum for receiving a wire into the drum,

a wire outlet (204) in an outlet end wall (202) of the drum for conveying the wire from the drum,

characterized in that said container further comprises

a channel (205) arranged about the sidewall of the drum, and tracing a substantially helical path, and

defining a hollow passage,

an inlet aperture (207) in the channel, opening into the hollow drum interior near the outlet end wall of the drum,

an outlet aperture (206) in the channel, opening into the hollow drum interior near the inlet end wall of the drum.
A lubrication container (2) as claimed in claim 1, wherein said drum (200) is substantially cylindrical.
A lubrication container as claimed in claim 1, wherein the drum is a substantially frustro-conical shape.
A lubrication container (2) as claimed in any one of claims 1 to 3, wherein the lubrication container (2) further comprises:
an outer drum (210), surrounding the drum (200) and forming a space (208) therebetween, the outer drum (210) and the drum (200) being co-axially aligned, and rotatable,

the channel (205) being disposed in the space (208) between the outer drum (210) and the drum (200).
A lubrication container (2) as claimed in any one of claims 1 to 4, wherein the channel (205) is formed on the outer surface of the drum (200).
A lubrication container (2) as claimed in any one of claims 1 to 5,wherein the pitch of said channel (205) results in said channel being angled between 0° to 20° relative to a vertical axis.
A lubrication container (2) as claimed in any one of claims 1 to 6 wherein the drum (200, 210) rotates about a horizontal axis.
A lubrication container as claimed in any one of claims 1 to 6 wherein the longitudinal axis of the drum (200, 210) is angled between 5° and 15° to the horizontal axis.
A lubrication container as claimed in any one of claims 1 to 8 wherein the drum (200, 210) comprises:
a plurality of channels (205) formed about the drum, in a multiple helical arrangement.
A lubrication container (2) as claimed in any one of claims 1 to 9 wherein the drum further comprises:
an opening (400) in the drum, the opening (400) allowing lubricant into the drum,

a removable lid (401) that can be placed over the opening (400) to close the opening and substantially seal the drum.
A lubrication container (2) as claimed in any one of claims 1 to 10 comprising a drive system adapted to rotate the drum (200, 210) at less than 10rpm.
A lubrication container (2) as claimed in any one of claims 1 to 11 wherein the inlet aperture (207) of the channel is out of phase with the outlet aperture (206) of the channel.
A lubrication container (2) as claimed in any one of claims 1 to 12 wherein the channel (205) is angled relative to the vertical angle, in manner to allow some of the lubricant to enter the channel (205) through the inlet aperture (207) of the channel and travel along the channel (205) toward the outlet aperture (206) of the channel as the drum rotates.
A lubrication container (2) as claimed in any one of claims 1 to 13 wherein the channel (205) traces less than two revolutions and at least half a revolution around the drum perimeter.
A method of lubricating wire in a wire drawing process comprising a lubrication container (2) as claimed in any one of claims 1 to 14, wherein in use, while rotating, the lubricant enters the channel (205) from the drum through the inlet aperture (207) in the channel and the lubricant exits the channel into the drum through the outlet aperture (206) in the channel, the lubricant travels along the channel (205) due to the rotation of the drum.