WO2015155641A1

WO2015155641A1 - Rotating lubrication system

Info

Publication number: WO2015155641A1
Application number: PCT/IB2015/052417
Authority: WO
Inventors: Roy Clifford WARNER; Alan BUYS
Original assignee: Cre8 Technologies Limited
Priority date: 2014-04-07
Filing date: 2015-04-02
Publication date: 2015-10-15

Abstract

A lubricant level sensor (29) for sensing a level of lubricant, preferably a powdered lubricant, within a rotating lubricant container (2), the level sensor comprising: a paddle (26) that is movable between a first position and a free position, and wherein said paddle is biased (28) towards said free position, a paddle position sensor (32) configured to detect the position of said movable paddle (26), and output a position signal at least when said paddle is in said free position, wherein said paddle (26) is rotated with said lubricant container (2) such that it moves through a measurement zone located toward the container bottom with each revolution of said container. Also disclosed is a rotating lubricant container (2) for use in wire drawing, a lubrication system and method for controlling lubricant level in such a rotating container.

Description

ROTATING LUBRICATION SYSTEM

FIELD OF THE INVENTION

The present invention relates to an apparatus for lubricating metal objects being drawn. In particular, the present invention relates to an improved 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, and maintaining temperature control. 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 lubricant container. The wire is pulled through the lubricant container and then through the drawing die. The wire is coated with the lubricant both as it is pulled through the lubricant container, and as it traverses the die. As the drawing process continues, the dry lubricant can become contaminated and performance can deteriorate.

A problem with known lubricant containers is that the lubricant does not get thoroughly mixed and the wire is not always exposed to fresh (meaning un- deteriorated) 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 lubricant 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 lubricant container for dry drawing. The lubricant container is rotated to agitate the dry lubricant and prevent deteriorated lubricants from accumulating around the drawing die. The lubricant container may also have protrusions that pulverize solidified lubricants as the container rotates. This leads to smaller particle size of the lubricant which can tend to perform better.

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 lubricant container. As a wire is drawn through the die, the lubricant is exposed to high pressure and temperature and deteriorates into solidified chunks. These solid lumps can prevent a consistent supply of lubricant to the wire or rod. As a result, the lubricant must be changed regularly, otherwise maximal lubrication may not be achieved and this can significantly affect the life of the die.

However, it is difficult to inspect and/or adjust the levels of lubricant within a rotating container because it is moving. Rotating containers at least present a potential health and safety hazard for any person operating it. Accordingly, the container must be stopped, which can be quite inconvenient and may even mean that the drawing process must be interrupted.

It is an object of the present invention to provide a lubricant container that goes some way to overcoming at least some 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 in a lubricant level sensor for sensing a level of lubricant within a rotating lubricant container comprising :

a paddle that is movable between a first position and a free position, and wherein said paddle is biased towards said free position,

a paddle position sensor configured to detect the position of said movable paddle, and output a position signal at least when said paddle is in said free position, wherein said paddle is rotated with said lubricant container such that it moves through a measurement zone located toward the bottom of said container with each revolution of said container, and

wherein when said paddle is not in said measurement zone (but at least about to enter said measurement zone), it is constrained to said first position, and

wherein when said paddle is in said measurement zone it is unconstrained, such that said bias may cause said paddle to move towards said free position, as the level of lubricant (if any)within said container, allows.

According to a further aspect said paddle is substantially rigid.

According to a further aspect said paddle is rotatably movable between said first position and said free position.

According to a further aspect said paddle rotates about a shaft with respect to said lubricant container between said first position and said free position, and

said shaft includes an eccentric cam follower that runs in a stationary track, such that as said paddle and said shaft rotates with said lubricant container:

said paddle is moved and constrained by said cam follower into said first position against said bias, at least before said paddle enters said measurement zone, and

said paddle is unconstrained by said cam follower and track when said paddle is in said measurement zone, such that it is free to move towards said free position, as the level of lubricant (if any), allows.

According to a further aspect said level sensor further comprises a controller configured to receive a signal from said detector indicative of a position of said paddle, such that said controller can calculate a level of lubricant within said container based on the movement of said paddle into said free position. According to a further aspect said paddle sensor is positioned relative to said rotating drum such that it detects said paddle in said free position only if a level of lubricant within said rotating container is below a predetermined threshold.

According to a further aspect said paddle sensor can be repositioned to correspond to a different predetermined threshold.

According to a further aspect said controller calculates a level of lubricant within said container based on the rotational position of said rotating container at a point in time when the paddle sensor indicates said paddle has moved to its said free position.

According to a further aspect each revolution of said rotating lubricant container includes one measurement zone, and each revolution causes said paddle to move to its first position prior to said paddle entering said measurement zone. According to a further aspect said first position and said free position are

approximately 45° apart.

According to a further aspect said measurement zone is located offset from a bottom dead centre position, towards the rising side of the lubricant container as it rotates.

In another aspect the invention can be said to broadly consist in a lubrication system comprising :

a hollow rotating lubricant container containing an amount of lubricant and having a wire inlet in an inlet end wall of the container, and a wire outlet in an outlet end wall of the container,

a level sensor configured to provide an indication of an amount of lubricant in said container,

a reservoir or hopper configured to feed additional lubricant into said container via a lubricant inlet,

a controller configured to receive a signal indicative of the amount of lubricant in said container from said level sensor, and to send an event signal if a first threshold is met.

According to a further aspect said level sensor provides said indication of the amount of lubrication in said container as said container rotates. According to a further aspect said flow of additional lubricant from said reservoir or hopper, to said lubricant container occurs as said container rotates.

According to a further aspect said container rotates to cause said lubrication to tumble within said container.

According to a further aspect said reservoir or hopper includes a flow control mechanism that can be actuated to dispense a controlled amount of lubricant to flow into said lubricant container. According to a further aspect said controller causes additional lubricant to flow from said reservoir or hopper to said container, via said lubricant inlet, if a second threshold is met.

According to a further aspect said controller provides a notification to a user if said controller receives said event signal.

According to a further aspect said first threshold is a minimum desired amount of lubricant contained in said container. According to a further aspect said level sensor is configured to provide said indication of the amount of lubricant in said container on every rotation of said lubricant container.

According to a further aspect said system is utilised in a wire drawing process.

According to a further aspect said lubricant is a soap.

According to a further aspect said controller receives a plurality of said signals from said level sensor as a result of a plurality of consecutive measurements, and sends a second event signal if a second threshold is met.

According to a further aspect said second threshold is said first threshold being met a predetermined proportion of times. According to a further aspect said predetermined proportion is one or more of: a. a predetermined number of consecutive times where said first threshold is met, or

b. a predetermined number of times where said first threshold is met, out of a predetermined number of consecutive received signals, or

c. a predetermined number of times where said first threshold is met.

According to a further aspect said first and second threshold is user configurable.

According to a further aspect said predetermined proportion is user configurable. According to a further aspect said lubricant container further comprises a closable first lubricant exit.

According to a further aspect said first lubricant exit is opened and closed on each rotation of said lubricant container, and wherein said first lubricant exit is opened when said container is rotationally positioned so that said first lubricant exit is positioned above a preferred predetermined maximum lubricant level within said container, such that an amount of lubricant above said preferred predetermined maximum level can flow through said first lubricant exit. According to a further aspect said first lubricant exit is closed when said container is rotationally positioned such that said first lubricant exit is below said preferred predetermined maximum lubricant level.

According to a further aspect said lubricant container includes a door to allow a user to fill or empty said container manually.

According to a further aspect said lubricant container rotates on a hollow shaft at an inlet end, and wherein said hollow shaft opens into said lubricant container, and

said hollow shaft includes a peripheral opening fluidly communicating with said hollow of said hollow shaft.

According to a further aspect said reservoir or hopper is configured to feed additional lubricant onto said hollow shaft such that lubricant flows through said hollow shaft and into said container when said peripheral opening is in registration with said reservoir or hopper. According to a further aspect said hollow shaft includes a plurality of said peripheral opening.

In another aspect the invention can be said to broadly consist in a rotating lubricant container comprising :

a hollow drum for holding lubricant, the drum being rotatable on a hollow shaft at an inlet end,

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 reservoir or hopper configured to feed additional lubricant

and wherein said hollow shaft opens into said hollow drum, and said hollow shaft includes a peripheral opening fluidly communicating with said hollow of said hollow shaft, and

said reservoir or hopper is configured to feed additional lubricant onto said hollow shaft such that lubricant flows through said hollow shaft and into said container when said peripheral opening is in registration with said reservoir or hopper.

According to a further aspect said hollow shaft includes a plurality of said peripheral openings.

According to a further aspect said level sensor is a level sensor of any one of claims 1 to 11.

In another aspect the invention can be said to broadly consist in a method of controlling the level of lubricant in a rotating lubricant container comprising the lubrication system of any one of the previous clauses.

In another aspect the invention can be said to broadly consist in a lubricant container for use in wire drawing, the lubricant 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 spiral or 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, and

a level sensor as claimed in any one of the previous clauses.

According to a further aspect the lubricant container further comprises:

an outer drum, surrounding the drum and forming a space there-between, 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.

According to a further aspect the drum rotates about a horizontal axis.

According to a further aspect the drum comprises:

a plurality of channels formed about the drum, in a multiple spiral or multiple helical arrangement.

According to a further aspect the drum further comprises:

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.

According to a further aspect a drive system rotates the drum at a speed allowing the channel to transport lubricant along the channel. According to a further aspect the drive system rotates the drum at less than lOrpm.

According to a further aspect the outlet end of the drum is positioned near to a die during a wire drawing process. According to a further aspect the inlet opening of the channel is out of phase with the outlet opening of the channel.

According to a further aspect the channel traces between half a revolution of the drum and five revolutions of the drum.

According to a further aspect the channel traces one or two revolutions of the drum. According to a further aspect the channel traces one revolution of the drum.

In another aspect the invention can be said to broadly consist in a method of lubricating wire in a wire drawing process comprising a lubricant container as claimed in 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. According to a further aspect the lubricant is constantly mixed due to the rotation of the drum.

According to a further aspect the lubricant being 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.

According to a further aspect the channel transporting 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.

According to a further aspect the lubricant enters the channel when the channel inlet is near the bottom of the drum and exits 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.

According to a further aspect the lubricant is re-circulated around the drum due to the movement of lubricant by the channel and by the rotation of the drum.

In another aspect the invention can be said to broadly consist in a lubricant container substantially as herein described with reference to any one or more of the Figures.

In another aspect the invention can be said to broadly consist in a method of lubricating wire substantially as herein described with reference to any one or more of the Figures. In another aspect the invention can be said to broadly consist in a lubrication system substantially as herein described with reference to any one or more of the drawings.

In another aspect the invention can be said to broadly consist in a level sensor substantially as herein described with reference to any one or more of the drawings.

According to a further aspect said system recirculates lubricant leaving said hollow lubricant container, and feeds it back into said reservoi r or hopper.

According to a further aspect said re-circulated lubricant is purified prior to entering said hopper.

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.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. The invention consists in the foregoing and also envisages constructions of which the following gives illustrative examples only.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of a rotating lubricant container showing liquidation inlet and outlet feeds.

Figure 2 is a cutaway perspective view of the rotating lubricant container of figure 1. Figure 3 is a perspective detailed view of the rotating lubricant container of figure 1 shown isolated .

Figure 4 is another perspective view of the rotating lubricant container of figure 1 shown isolated . Figure 5 is a cutaway perspective view of the apparatus of figure 1 showing the bulkhead in which the chamber rotates.

Figure 6 is another perspective view of the rotating lubricant container figure 4, showing the level sensor configuration.

Figure 7 is another perspective view of the rotating lubricant container figure 4, showing the overflow door.

Figure 8 is an isolated view of a component of the level sensing apparatus.

Figure 9 is a close-up schematic view of the bulkhead of figure 5, illustrating the operation of the level sensor. DETAILED DESCRIPTION

The present invention relates to a rotating lubricant container for wire drawing. In particular, our previous invention described in WO2012/085885, provides a

particularly effective application of lubricant. The contents of this document are herein incorporated in their entirety by reference. We have found that the invention described in that document can prolong the life of the wire drawing dies by around a factor of two.

The present inventions are further improvements that find particularly useful application in combination with our own previous designs. However, the present designs also find application in rotating lubricant containers generally.

Figure 1 shows a rotating lubricant container as it would be installed in a 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 rotating lubricant container 2, driven by motor 3, via drive belt 4. The lubricant container 2 is positioned within a housing 5. The housing 5 includes two end supports to retain the lubricant container 2 in the housing 5. Each support structure includes bearings to rotatably support the container 2, about a substantially horizontal axis. Alternatively, the container may be sloped with respect to the horizontal. For example, approximately 10 degrees, so that the outlet end is lower.

In the preferred form the drive system includes a belt 4 that 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 lubricant container 2.

The housing 5 includes a wire entrance opening 6 at one end (left hand side of Figure 1) of the housing that receives a metal wire or rod, and a wire exit opening 7 at the other end of the housing. When installed in a wire drawing machine (WDM) the wire exit 7 passes the wire out into the drawing die (not shown).

The wire entrance 6 and the wire exit 7 are longitudinally opposed and are located at opposite ends of the housing 5. The wire entry opening 6 and wire exit opening 7 are preferably aligned along a common longitudinal axis.

The drawing die is preferably longitudinally aligned (co-axial) with the wire exit opening 6 and receives lubricated wire for drawing through the die, from the wire exit opening 7. The wire is lubricated in the lubricant container 2 as it passes through the powdered lubricant (soap) within, and into the die. The die may be of any type appropriate for the drawing process that is being performed, and can be any suitable die for drawing wire.

In one preferred form, the die may be a rotating die, wherein the die preferably rotates about the common axis.

Alternatively any other pressure die or other suitable die may be used.

The preferred embodiments of the lubricant container 2 will now be described in greater detail particularly with respect to Figure 3. The lubricant container 2 comprises a double skinned drum. The double skinned drum comprises an inner wall 8 and an outer wall 9.

The inner and outer walls are preferably generally cylindrical and co-axially aligned along the longitudinal axis. The inner wall 8 defines a lubricant space 10 to hold lubricant or soap used for wire drawing operations. The lubricant can be any suitable powdered, granulated or pelletized 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, in order to effectively coat the wire.

The inner and outer walls 8, 9 include an opening 11 to fill the inner lubricant space 10 with lubricant. A door lid 12 is provided to close the opening and seal the contents of the inner drum. The lid 12 is preferably formed to conform substantially to the shape of the opening 11 so that a sealed closure is formed.

The lubricant container 2 includes an inlet end wall 13 and an outlet end wall 14. A wire inlet opening 6 is formed in the inlet end wall 13 and a wire outlet opening 7 is formed in the outlet end 14 wall.

The lubricant container 2 further comprises a channel or passage 15 arranged about the side wall of the lubricant container 2. In one embodiment the channel 15 is formed or disposed within the space between the inner and outer walls 8,9. The channel 15 preferably traces a spiral or helical path around the perimeter of the lubricant container about the longitudinal axis.

The channel 15 preferably forms a sealed pathway between its ends and preferably traces a path that is a full revolution about the longitudinal axis, as seen in figure 3. Alternatively the channel may complete anywhere between half and five revolutions (or spirals) about the axis.

The channel 15 includes an outlet aperture 16 at one end of the channel, and an inlet aperture 17 at the other end channel. This is shown in Figure 3, where the outlet aperture 16 is nearer the wire inlet opening 6, while the inlet aperture 17 is nearer the wire outlet opening 7.

The outlet aperture 16 and the inlet aperture 17 are preferably diametrically opposed to each other such that they are positioned out of phase with each other as the lubricant container rotates about its axis.

Alternatively the outlet aperture 16 and inlet aperture 17 may be aligned or out of phase by any angle between 0 and 360 degrees. In other forms the channel 15 may comprise a plurality of inlet apertures and outlet apertures, each at respective ends of channel 15. Further alternative embodiments may comprise multiple channels arranged in a multiple helix or spiral arrangement spaced around the perimeter of the container 2. It is important that the nature of the spiral path that passage 15 traces around the lubricant 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 will be appreciated that the steepness of the passage will encourage the powdered lubricant to fall under the influence of gravity more effectively.

The lubricant container is rotated to constantly redistribute the lubricant within. The channel 15 operates to transport some of the lubricant from near the wire outlet 7 to near the wire inlet opening 6, and preferably has a smooth inner surface.

As the lubricant container rotates, the inlet aperture 17 rotates and arrives at the bottom of the lubricant container. As the inlet aperture 17 approaches the bottom of the container, some of the lubricant (soap) within drops into the channel 15 through the inlet aperture 17.

As the drum rotates further, the lubricant in the channel 15 moves along the channel 15, from near the wire outlet opening 7, toward the wire inlet opening 6. That is, the parcel is lifted up the sidewall of the container. The lubricant travels along the channel 15 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 16 of the channel 15, and the lubricant drops out of the outlet aperture 16. It will be appreciated that the direction of container rotation with respect to the helix direction is important for efficiency of operation. If rotated in the opposite direction the parcels of lubricant may still move along the passage, but not as effectively. As the lubricant container rotates, the channel 15 collects a "parcel" of lubricant on every revolution and transports the parcel along the channel 15. 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 15 when the inlet aperture 17 is at (or near) the bottom of the drum. A new "parcel" enters channel 15 every time the inlet aperture is immersed in lubricant as it arrives at the bottom of the container. 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.

The lubricant container is preferably rotated at approximately 2RPM. However, the container may be rotated at any suitable speed from approximately 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 is between 2RPM and 6RPM.

The soap (lubricant) is more effectively transported along the channel 15 at slower drum rotational speeds. At higher speeds the forces, due to the rotation, cause the lubricant to stick to walls hence there is no movement of lubricant.

The channel 15 is advantageous because it creates a redistribution of the lubricant within the container. 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 7. The contaminated or deteriorated lubricant does not accumulate near the wire outlet 7 because it is continually taken from the die end, transported away, and deposited at the other end by the channel 15.

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 rotating container is installed. The rotating container lubrication system above has been found to achieve a very high and consistent lubrication of wire passing through it. This requires lubricant to be frequently added to the container to "top up" the level.

Further, it has been found that the process may benefit from periodic emptying of the lubricant and re-filling with fresh lubricant in order to remove lubricant contamination. However, because the container is constantly moving (rotating), it is difficult to interact with it. Health and safety considerations make it difficult to access the container (via opening 11 for example), even if the rotation of the container is stopped, due to the wire still passing through it.

Further, it is desirable if one or more of these tasks can be performed without stopping or even slowing the container.

With particular reference to figures 1,2 & 6, a preferred feed system will be described in more detail. The hollow drum 2 for holding lubricant, is rotatable on a hollow shaft 18 (at an inlet end), and a reservoir or hopper 21 is configured to feed additional lubricant into the rotating container. The hollow shaft 18 opens into the interior space of the lubricant container, and the hollow shaft 18 includes at least one peripheral opening 19 that is fluidly connected with the hollow shaft.

In order to feed additional lubricant to the container, the reservoir or hopper 21 is configured to feed additional lubricant, via gravity, through chute 20 onto the hollow shaft 18 such that lubricant flows through feed aperture(s) 19 into the hollow shaft, when said peripheral feed aperture 19 is in registration with the chute 20 outlet.

Preferably the chute 20 is reverse tapered (outlet of greater cross section area than inlet) to ensure there is no compression of the powdered lubricant, resulting in blockages. Further, preferably the feed aperture 19 is slightly larger than the chute 20 opening, in order to remove any protuberances that may also lead to blockages.

When operating, it will be appreciated that lubricant is fed from the hopper 21, through the chute 20, to the outer periphery of the hollow shaft 18. As the container 2 rotates, the feed aperture(s) 19, will periodically become aligned with the outlet of chute 20, at which point lubricant will flow into the hollow shaft 18 and contact the wire passing through it. The wire being drawn drags the lubricant from the hollow shaft into the container. With reference to Figure 6, a gasket 40 may be provided to prevent lubricant from flowing against the direction of the wire being drawn.

The result of the arrangement is that fresh lubricant can be fed into the rotating container, while it is still rotating. It is envisaged that the hopper may include a flow control device to turn the flow of fresh lubricant on or off.

Alternatively, the hopper may include a flow control device to meter the flow of fresh lubricant. Alternatively still, the hopper may constantly allow flow of fresh lubricant into the container.

In addition to an in-feed system, the rotating container may also include an out-feed system. For example, with particular reference to Figures 3 & 7 an out-feed door 22 is provided.

Out feed door 22 is hinged and biased into a closed position to prevent lubricant from leaving the rotating container. However, a door 22 can be opened when the lubricant exit 22 is positioned so that it is located above a preferred predetermined maximum lubricant level within the rotating container. Accordingly, when the door 22 is opened, an amount of lubricant above a preferred predetermined maximum level, can flow through the opening and into a collector chute 23.

Preferably, door 22 is actuated via cam lever 24 on each rotation of the lubricant chamber.

Accordingly, a mechanism is provided for removing any lubricant above a

predetermined preferred maximum level. It will be appreciated that the predetermined level can be changed by changing the position (rotational position of the lubricant container) at which the door 22 is opened.

Preferably, the door 22 is opened periodically. For example, on every revolution of the lubricant container, or after a predetermined number of revolutions. An auxiliary door 25 may also be provided (preferably in-line with door 22) to allow emptying of the lubricant in the rotating container onto chute 23 when the door is at the bottom. For example, it may be necessary to replace all the lubricant periodically, and door 25 may be opened for this purpose. With reference to Figure 4 & 7, door 25 is a sliding door. When held open as shown in figure 7, lubricant from the container will flow out (onto collector chute 23) as the container rotates, or is stationary. It may be desirable that a flow of fresh lubricant into the rotating container can be achieved. It will be appreciated that lubricant will be depicted during wire drawing. Inflow of fresh lubricant may be provided with or without flow of used lubricant out of the rotating container. If both inflow and outflow is provided, impurities and/or contaminants in the lubricant may be removed online (i.e. as the rotating lubricant container rotates, via the overflow door 22), while at the same time the level of lubricant is maintained and replenished by new lubricant being added via chute 20.

One advantage of the overflow door as described above, it is not particularly important that the inflow feed rate is perfectly matched, because any extra lubricant will simply be removed from the container via the overflow door 22.

It is envisaged that used lubricant flowing from the rotating container may additionally be purified, before being recycled back into the rotating chamber through the hopper. Any known purification methods may be employed, and purification may occur autonomously in a continuous loop that feeds back into the hopper 21. Alternatively, used lubricant may simply be taken from the device and purified, before being reused at a later time.

Level sensor

In order to allow autonomous or semi-autonomous control of the lubricant level in the rotating lubricant container 2, it is desirable that the lubrication level can be measured accurately.

Even in designs that have no autonomous control of the lubricant level anticipated, (i .e. where lubricant level is manually maintained), it may still be desirable to accurately measure the lubricant level, so that a user/operator can track it. For example, the system may issue a warning (such as an audible or visual indication, or both), in order to alert a user to a low and/or high lubricant powder level, within the rotating lubricant container 2. However, it is difficult to accurately measure a lubricant level within a rotating lubricant container 2, because the lubricant is constantly moving due to the rotation of the container 2. Further, the environment in which the lubricant container 2 operates, is somewhat hostile, and can result in inaccurate and/or unreliable sensing. Further, it is highly desirable to sense and monitor the lubricant level within the rotating lubricant container 2, while the container 2, continues to operate (i.e. rotate).

With particular reference to figures 4 to 6, and 8 and 9, a preferred level sensor assembly 29 will be described in more detail. Paddle 26 is located on the inlet end wall 13, of lubricant container 2, and as such the level sensing assembly (including paddle 26) moves with the lubricant container 2 as it rotates. However, it will be appreciated from the coming description that the level sensor paddle 26 can be located elsewhere within lubricant container 2. Paddle 26 is rotatably mounted on a shaft 27, such that it may rotate between a first position, and a free position (shown in figure 8). Spring 28 is provided to bias the shaft and paddle assembly 27, 26 into the free position.

At the output end of shaft 27, is an eccentric cam follower 30 that operates like a crank to rotate (or be rotated by) shaft 27. An end stop 31, is provided such that spring 28 biases paddle 26 until the crank arm abuts end stop 31, at which point the level sensing assembly 29 is in the free position.

With particular reference to figure 5, the end wall insert 34 of housing 5 is shown. This figure is shown with the rotating lubricant container 2 removed, but for illustration purposes, the sensor assembly 29 and paddle 26 are shown.

As noted above, the level sensing assembly 29 rotates with lubricant container 2, and cam follower 30 thereby runs in track 33. On each revolution of the lubricant container 2, the level sensing assembly 29 is moved through a measurement zone (this zone being towards the bottom of the lubricant container 2).

The paddle 26 is spring-loaded by biasing spring 28 such that when it is buried in lubricant powder, the volume of powder interacting with paddle 26 is too massive for the spring 28 to move paddle 26 through the powder volume. However, when paddle 26 is not sufficiently buried in lubricant powder, the biasing spring 28 is sufficient to move paddle 26 (even with a 'pile' of powder on it, towards its free position.

With particular reference to figure 9, the guide track 33 interacts with the cam follower 30 to place paddle 26 into a 'set' position before it is buried in powder in the measurement zone C (when the level sensing assembly 29 is towards the bottom of rotating container 2). For illustration purposes, a "low powder level" line 36 and a "high powder level" line 37 are shown, and oriented at an angle due to the rotation of the lubricant container 2, that causes the powder to 'climb' the wall and tumble. It can be seen in zone "A" (the reset zone) that the cam surface of the track 33, moves paddle 26 in direction of arrow 35, as the lubricant container 2 rotates clockwise. In position Al, the cam follower 30 is just contacting the cam surface of track 33, and paddle 26 is not oriented radially towards the centre of rotating drum 2. As the cam follower 30, contacts track 33, the paddle 26 begins moving from its free position. Further around in position A2, the cam follower 30 and paddle 26 are almost completely returned to the set position, where the paddle 26 is oriented approximately radially.

In the set position (zone "B"), paddle 26 extends approximately radially towards the centre of lubricant container 2. When in this position, it will be appreciated that the track 33 constrains the paddle assembly 29, as it moves towards the measurement zone and becomes buried in lubricant powder at the bottom of the rotating lubricant container 2. As the paddle 26 is buried in powder towards the bottom of the lubricant container 2, in the measurement zone "C", the track 33 releases cam follower 30 so that the paddle is free to rotate (in the absence of sufficient lubricant to prevent its

movement). In zone CI, the cam follower 30 is just about to become free of the constraint from track 33.

As the level sensing assembly 29 moves into position C2, (with the lubricant powder at the low level as illustrated by line 36), the assembly is near proximity sensor 32. This proximity sensor 32 is positioned and located such that it can detect movement of the cam follower 30 (into the free position) if the paddle springs free of lubricant powder in its vicinity or before. Preferably the sensor position is adjustable so that it triggers at various predetermined minimum lubricant levels. At position C2, it can be seen that paddle 26 has emerged from the lubricant powder (at low level 36) sufficiently to rotate towards its free position. This movement, causes the cam follower to trigger the proximity sensor 32.

It will be appreciated that if the paddle 26 has rotated into its free position before the cam follower passes the proximity sensor 32, then the sensor will be also be triggered.

However, if the paddle 26 rotates after it passes the vicinity of the proximity sensor 32, the cam follower 30 misses the location of the proximity sensor 32, and the sensor 32 is not triggered . For example, in the position just prior to that illustrated by Al, the paddle 26 is emerging from the high powder level illustrated by line 37. In this position, the cam follower is too far away from proximity sensor 32 in order to trigger sensor 32.

Accordingly, it will be appreciated that when the powder level within the rotating lubricant container 2 is beyond a minimum level, the level detection sensor 32 will not trigger. As result, the triggering of the sensor 32, can be used to determine the powder level, within the lubricant container.

One advantage of the above described level sensing assembly is that the paddle 26 is maneuvered through its full range of motion every revolution of lubricant container 2 to ensure freedom of movement. This prevents binding and ensures reliability of the sensor.

In this regard, it will be appreciated that the use of the track and cam follower arrangement that is external to the lubricant container also contributes to reliability, and obviates the need for sensors to be located within the hostile and rotating lubricant container itself.

It will be appreciated that the above described level sensor assembly is capable of providing an event signal when the powder lubricant level within the rotating lubricant container 2, falls below a predetermined (and adjustable) desired level.

However, in an alternative embodiment it may be desired to obtain a measure indicative of the actual level of powdered lubricant within the rotating lubricant container 2. That is, it may be desirable to provide a scale (between low and high for example), of the amount of powdered lubricant within the container 2. Such a system may be achieved with relatively minor modification if desired. For example, the proximity sensor 32 may be arranged to detect movement of the paddle 26 into its free position at any stage. In addition, a rotary encoder coupled to the lubricant container 2 may be used to determine the rotational position of the lubricant container 2. It will be appreciated that any suitable means of measuring the position may be employed.

A controller can then be used to determine the level of powdered lubricant within a rotating container 2, by correlating the rotational position of container 2 at which the paddle 26 "breaks free" of the lubricant powder level within the container 2.

Control system

In order to provide autonomous or semi-autonomous control, an appropriate controller system may be employed.

The above examples describe a rotating lubricant container system that is capable of in-feeding fresh lubricant, and determining how much lubricant remains in the lubricant container 2. Accordingly, a controller may be employed to take action when it receives a signal from the level sensing assembly 29, that requires action.

In one form, the refilling may be a manual process and the controller simply activates a warning (visual or audible or otherwise) to alert a user to a low powder level condition. The operator of the system may then make a decision as to when to utilise the hopper to introduce more powder into the rotating lubricant container 2.

In another form, the system may be autonomous and the controller may be

configured to actuate a flow control mechanism associated with the hopper, in order to cause fresh powder to be introduced. Similarly, in yet further forms where autonomous or semiautonomous purification of used lubricant powder extracted from the rotating lubricant container 2 is employed, the controller may be configured to control the entire process.

In the most preferred forms, the controller may employ appropriate logic algorithms to ensure that the appropriate actions are taken even in situations where the level sensor may return a 'false' trigger. For example, the conditions within the rotating lubricant container 2 are potentially quite dynamic, and as a result, it is possible that the level sensor will trigger a low powder signal, even if the powder level is sufficient.

In order to account for this possibility, it is envisaged that the controller may utilise logic to analyze a trend of low powder event signals, rather than simply relying on a single event. With reference to figure 9, micro switch 39 is activated momentarily every revolution of lubricant container 2. The switch combined with the level sensor 29 allows the controller to associate a low powder level event signal, with a single rotational circuit of the lubricant container 2.

In particular, the controller may utilize resettable counters to build a cumulative total of low powder event signals. As a result, erroneous low powder event signals can be ignored. The trend building principle and the physical resetting of the sensor each revolution eliminates unreliability. It is envisaged that a number of threshold parameters may be employed, either separately or in parallel. That is, there may be a single threshold, or the controller may make a decision to take an action (such as allow fresh lubricant to flow into the container, or trigger a visual or audible alarm), if any one of a number of thresholds are triggered.

For example, the threshold may be:

• the receipt of a low powder signal a predetermined number of times from

consecutive container rotations, or (e.g. 3 low powder triggers in consecutive revolutions of lubricant container 2)

· a 'moving window' type calculation wherein the receipt of a low powder signal a predetermined proportion of times (e.g. 3 low powder triggers, in a window of any 10 consecutive rotations)

• Upon the accumulation of a preset total (for example when the counter reaches 5, a warning event may be triggered)

o Further, the counter may be reset for example if a decision is made to top up the lubricant container, upon receipt of the first warning event, o Alternatively, if the warning event is ignored, the counter may continue accumulating until another higher threshold is reached,

o At the higher threshold, a further warning event may be triggered, or alternatively the system may be shut down to avoid damage. o It will be appreciated that a series of such, cascading thresholds may be employed before, a final shutdown step is initiated.

Importantly, the system preferably allows the thresholds to be altered and set. For example, it is anticipated that various installations may require different/varying thresholds based on any number of physical differences between the systems. For example, the type of lubricant used, the size of the lubricant container, the rotational speed of the lubricant container, and many other factors may affect what type of thresholds are appropriate and where those thresholds should be set for reliability.

Claims

1. A lubricant level sensor for sensing a level of lubricant within a rotating lubricant container comprising :

2. A level sensor as claimed in claim 1, wherein said paddle is substantially rigid.

3. A level sensor as claimed in any one of the previous claims, wherein said paddle is rotatably movable between said first position and said free position.

4. A level sensor as claimed in claim 3, wherein said paddle rotates about a shaft with respect to said lubricant container between said first position and said free position, and

5. A level sensor as claimed in any one of claims 1 to 4, wherein said level sensor further comprises a controller configured to receive a signal from said detector indicative of a position of said paddle, such that said controller can calculate a level of lubricant within said container based on the movement of said paddle into said free position.

6. A level sensor as claimed in claim 5, wherein said paddle sensor is positioned relative to said rotating drum such that it detects said paddle in said free position only if a level of lubricant within said rotating container is below a predetermined threshold.

7. A level sensor as claimed in claim 6, wherein said paddle sensor can be repositioned to correspond to a different predetermined threshold.

8. A level sensor as claimed in claim 5, wherein said controller calculates a level of lubricant within said container based on the rotational position of said rotating container at a point in time when the paddle sensor indicates said paddle has moved to its said free position.

9. A level sensor as claimed in any one of claims 1 to 8, wherein each revolution of said rotating lubricant container includes one measurement zone, and each revolution causes said paddle to move to its first position prior to said paddle entering said measurement zone.

10. A level sensor as claimed in any one of claims 3 to 9 wherein said first position and said free position are approximately 45° apart.

11. A level sensor as claimed in any one of claims 1 to 10 wherein said

measurement zone is located offset from a bottom dead centre position, towards the rising side of the lubricant container as it rotates.

12. A lubrication system comprising :

a reservoir or hopper configured to feed additional lubricant into said container via a lubricant inlet, a controller configured to receive a signal indicative of the amount of lubricant in said container from said level sensor, and to send an event signal if a first threshold is met.

13. A lubrication system as claimed in claim 12, wherein said level sensor provides said indication of the amount of lubrication in said container as said container rotates.

14. A lubrication system as claimed in any one of claims 12 to 13, wherein said flow of additional lubricant from said reservoir or hopper, to said lubricant container occurs as said container rotates.

15. A lubrication system as claimed in any one of the claims 12 to 14, wherein said container rotates to cause said lubrication to tumble within said container.

16. A lubrication system as claimed in any one of claims 12 to 15, wherein said reservoir or hopper includes a flow control mechanism that can be actuated to dispense a controlled amount of lubricant to flow into said lubricant container.

17. A lubrication system as claimed in the previous claim wherein said controller causes additional lubricant to flow from said reservoir or hopper to said container, via said lubricant inlet, if a second threshold is met.

18. A lubrication system as claimed in any one of claims 12 to 17, wherein said controller provides a notification to a user if said controller receives said event signal.

19. A lubrication system as claimed in any one of claims 12 to 18, wherein said first threshold is a minimum desired amount of lubricant contained in said container.

20. A lubrication system as claimed in any one of claims 12 to 19, wherein said level sensor is configured to provide said indication of the amount of lubricant in said container on every rotation of said lubricant container.

21. A lubrication system as claimed in any one of claims 12 to 20, wherein said system is utilised in a wire drawing process.

22. A lubrication system as claimed in any one of claims 12 to 21, wherein said lubricant is a soap.

23. A lubrication system as claimed in any one of claims 12 to 22, wherein said controller receives a plurality of said signals from said level sensor as a result of a plurality of consecutive measurements, and sends a second event signal if a second threshold is met.

24. A lubrication system as claimed in claim 23, wherein said second threshold is said first threshold being met a predetermined proportion of times.

25. A lubrication system as claimed in claim 24 wherein said predetermined proportion is one or more of:

a. a predetermined number of consecutive times where said first threshold is met, or

c. a predetermined number of times where said first threshold is met.

26. A lubrication system as claimed in any one of claims 12 to 25, wherein said first and second threshold is user configurable.

27. A lubrication system as claimed in any one of claims 12 to 26, wherein said predetermined proportion is user configurable.

28. A lubrication system as claimed in any one of claims 12 to 27, wherein said lubricant container further comprises a closable first lubricant exit.

29. A lubrication system as claimed in claim 28, wherein said first lubricant exit is opened and closed on each rotation of said lubricant container, and wherein said first lubricant exit is opened when said container is rotationally positioned so that said first lubricant exit is positioned above a preferred predetermined maximum lubricant level within said container, such that an amount of lubricant above said preferred predetermined maximum level can flow through said first lubricant exit.

30. A lubrication system as claimed in claim 29, wherein said first lubricant exit is closed when said container is rotationally positioned such that said first lubricant exit is below said preferred predetermined maximum lubricant level.

31. A lubrication system as claimed in any one of claims 12 to 30, wherein said lubricant container includes a door to allow a user to fill or empty said container manually.

32. A lubrication system as claimed in any one of claims 12 to 31, wherein said lubricant container rotates on a hollow shaft at an inlet end, and wherein said hollow shaft opens into said lubricant container, and

33. A lubrication system as claimed in claim 32, wherein said reservoir or hopper is configured to feed additional lubricant onto said hollow shaft such that lubricant flows through said hollow shaft and into said container when said peripheral opening is in registration with said reservoir or hopper.

34. A lubrication system as claimed in claim 32 or claim 33, wherein said hollow shaft includes a plurality of said peripheral opening.

35. A rotating lubricant container comprising :

a reservoir or hopper configured to feed additional lubricant

36. A lubrication system as claimed in claim 35 wherein said hollow shaft includes a plurality of said peripheral openings.

37. A lubrication system as claimed in any one of claims 12 to 36, wherein said level sensor is a level sensor of any one of claims 1 to 11.

38. A method of controlling the level of lubricant in a rotating lubricant container comprising the lubrication system of any one of claims 12 to 36.

39. A lubricant container for use in wire drawing, the lubricant container comprising :

a channel arranged about the sidewall of the drum, and tracing a substantially spiral or 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,

a level sensor as claimed in any one of claims 1 to 11.

40. A lubricant container as claimed in claim 39, wherein the lubricant container further comprises:

the channel being disposed in the space between the outer drum and the drum

41. A lubricant container as claimed in any one of claims 39 to 40, wherein the drum rotates about a horizontal axis.

42. A lubricant container as claimed in any one of claims 39 to 41, wherein the drum comprises:

43. A lubricant container as claimed in any one of claims 39 to 42, wherein the drum further comprises:

44. A lubricant container as claimed in any one of claims 39 to 43, wherein a drive system rotates the drum at a speed allowing the channel to transport lubricant along the channel.

45. A lubricant container as claimed in claim 44, wherein the drive system rotates the drum at less than lOrpm.

46. A lubricant container as claimed in any one of claims 39 to 45, wherein the outlet end of the drum is positioned near to a die during a wire drawing process.

47. A lubricant container as claimed in any one of claims 39 to 46, wherein the inlet opening of the channel is out of phase with the outlet opening of the channel.

48. A lubricant container as claimed in any one of claims 39 to 47, wherein the channel traces between half a revolution of the drum and five revolutions of the drum.

49. A lubricant container as claimed in any one of claims 39 to 48, wherein the channel traces one or two revolutions of the drum.

50. A lubricant container as claimed in any one of claims 39 to 49, wherein the channel traces one revolution of the drum.

51. A method of lubricating wire in a wire drawing process comprising a lubricant container as claimed in any one of claims 39 to 50, 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.

52. A method as claimed in claim 51, wherein the lubricant is constantly mixed due to the rotation of the drum.

53. A method as claimed in claim 51 or 52, wherein the lubricant being 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.

54. A method as claimed in any one of 51 to 53, wherein the channel transporting 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.

55. A method as claimed in any one of claims 51 to 54, wherein the lubricant enters the channel when the channel inlet is near the bottom of the drum and exits 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.

56. A method as claimed in any one of claims 51 to 55, wherein the lubricant is recirculated around the drum due to the movement of lubricant by the channel and by the rotation of the drum.

57. A lubricant container substantially as herein described with reference to any one or more of the Figures.

58. A method of lubricating wire substantially as herein described with reference to any one or more of the Figures.

59. A lubrication system substantially as herein described with reference to any one or more of the drawings.

60. A level sensor substantially as herein described with reference to any one or more of the drawings.

61. A lubrication system as claimed in any one of claims 28 to 34, wherein said system recirculates lubricant leaving said hollow lubricant container, and feeds it back into said reservoir or hopper.

62. A lubrication system as claimed in claim 61, wherein said re-circulated lubricant is purified prior to entering said hopper.