GB2361269A

GB2361269A - Adjustable lubricant dispenser

Info

Publication number: GB2361269A
Application number: GB0108051A
Authority: GB
Inventors: John Ross Bowers Kennedy
Original assignee: QUAYHEAD IND Ltd
Current assignee: QUAYHEAD IND Ltd
Priority date: 2000-03-30
Filing date: 2001-03-30
Publication date: 2001-10-17
Anticipated expiration: 2021-03-30
Also published as: GB2361269B; GB0108051D0; GB0007772D0

Abstract

A lubricant dispenser 10 suitable for dispensing grease, comprises:<BR> inlet means 12 adapted to connect the dispenser to a lubricant reservoir;<BR> a positive displacement pump mechanism (see figures 8 to 10);<BR> activation means 18, 19 adapted to activate the positive displacement pump mechanism; and<BR> outlet means 13, 14 adapted to direct the lubricant dispensed by the dispenser to its intended target. The lubricant dispenser may be mounted by adjustable clamping means (figure 14) onto a rail to supply grease to the rail when the activation means 18, 19 are depressed by the wheel of a train. The quantity of lubricant dispensed on each activation may also be controlled, through rotatable stop 34 (figure 10). A pressure transducer may be provided to monitor the outlet.

Description

2361269 ADJUSTABLE LUBRICANT DISPENSER

Field of the Invention 5

The present invention relates to lubricant dispensers. It is particularly applicable, but in no way limited, to grease dispensers.

BacEground to the Invention Dispensers which dispense grease are used extensively on railway systems for providing lubrication for the wheels/track on bends. The wheels on trains are subject to considerable wear when a train goes round a curved portion of track, ie on bends. The smaller or tighter radius of the bend the greater the liability to wear. This tendency to wear is generally offset by lubricating the side or edge of the track as the train negotiates the bend. Without such lubrication the inside edges of the wheels would wear very quickly, resulting in costly maintenance and train downtime.

Lubrication dispensers for this purpose are known and these generally dispense an aliquot or aliquots of grease onto the appropriate regions on the rail as the train wheels pass over that part of the track. However, it is important that the amount of grease dispensed on each activation is carefully controlled and relatively constant and that no airlocks are introduced into the system in the process. These lubrication dispensers can be, and often are, located on very busy stretches of track. They are also, of necessity, activated every time a train passes by. It follows, therefore, that if a dispenser provides more grease than was originally specified, then after multiple applications a significant excess of grease will build up on that region of the track. This could result in some of the grease spilling over or otherwise being carried onto the top portion of the rail. This can have a serious and potentially disastrous effect on train breaking and stopping distances and should be avoided if at all possible.

1 Furthermore, dispensing more grease than is actually required also causes the grease reservoir supplying the dispenser to empty more quickly than it would otherwise do. Since there are many thousands of these dispensers, and thus grease reservoirs, around the railtrack system in the UK, this can greatly increase the cost and inconvenience of maintenance.

It is therefore an object of the present invention to provide a lubrication dispenser which can be accurately calibrated to dispense a pre-determined amount of grease without allowing air to enter the system.

Summary of the Invention

According to the present invention there is provided a lubricant dispenser suitable for dispensing grease, said dispenser comprising:- (i) inlet means adapted to connect the dispenser to a lubricant reservoir; (ii) a positive displacement pump mechanism; 15 (iii) activation means adapted to activate the positive displacement pump mechanism; (iv) outlet means adapted to direct the lubricant dispensed by the dispenser to its intended target.

Incorporating a positive displacement pump into this type of dispenser provides, for the first time, significantly more accurate dispensing of the lubricant.

Preferably the activation means comprises a plunger and piston arrangement operating within a cylinder bore, the piston preferably moving between an upper "at resC position and a lower 1ubricant expelleT position.The activation means may be one and the same as the pump mechanism, or a part of it or discrete but operatively linked to it.

2 Preferably the dispenser further comprises a dispenser body, said body incorporating passageways connecting the inlet means, cylinder bore and outlet means.

Preferably the piston incorporates apertures adapted to allow lubricant to pass through the piston from the inlet means into the cylinder bore on the upstroke of the piston as it returns from the 1ubricant expelled" position to the "at resC position. Feeding lubricant through the top of the piston significantly reduces the possibility of air being entrained into the lubricant and thus improves the reliability of the dispenser.

Preferably the apertures in the piston incorporate a first non-retum valve mechanism said mechanism being biased into a closed position by a biasing means, the biasing means being adapted to allow lubricant from the reservoir to enter the cylinder bore on demand whilst keeping the nonreturn valve closed during the down stroke of the piston.

In a particularly preferred embodiment the position of the piston in its upper "at rest" position is adjustable, such that the volume of lubricant in the cylinder bore and thus the volume of lubricant available for dispensing is adjustable. This adjustment is preferably provided by a moveable stop above the piston. In one embodiment this stop takes the form of an off- centre spigot in the end of a rotatable member. Rotating the member moves the stop up or down according to the volume of lubricant required.

Preferably the bottom of the cylinder bore incorporate a second nonreturn valve mechanism, adapted to prevent lubricant propelled into the outlet means from reentering the cylinder bore.

Preferably the pump body is adapted to accommodate two plunger units, one on either side of the lubricant inlet. The dispenser can, however, be operated with only a single plunger unit where very small dosages are required.

3 Preferably the lubricant dispenser incorporates a mounting means adapted to clamp the dispenser onto a rail of a railway track. In a particularly preferred embodiment the mounting means clamps symmetrically to both sides of the rail.

Preferably the mounting means incorporates both height and width adjustment 5 to enable the location of the top of the plunger in relation to the top of the rail to be adjusted within certain pre-determined limits.

In a further aspect, the invention comprises the combination of a lubricant dispenser as herein described together with a grease reservoir.

In a still further aspect the invention comprises a lubricant dispenser incorporating a pressure transducer adapted to provide information regarding the status of the dispenser. Preferably the pressure transducer provides a signal indicating the pressure produced as a slug of lubricant is dispensed into the outlet means. In a particularly preferred embodiment the pressure transducer generates an alarm signal if the pressure during the pumping action exceeds or drops below pre-determined values.

Description of the Drawings

The invention will be further described, by way of example only, with reference to the accompanying drawings in which:- Figure 1 shows a perspective view of a lubricant dispenser according to the present invention; Figure 2 shows the lubricant dispenser of Figure 1 with the rail and some of the mounting means removed; Figure 3 shows the lubricant dispenser of Figure 2 with the mounting brackets removed; 4 1 Figures 4 to 11 show part exposed and expanded views of the lubricant dispenser illustrated in Figure; Figure 12 shows various diagrammatic isometric views of left-hand (Figs 12A, 12B, 12C) and right-hand (Figs 12D, 12E, 12F) pump bodies; Figure 13 illustrates a side elevational view of a dispenser according to Figure 1 showing the mounting means in more detail; Figures 14 to 16 illustrate various components of the mounting means; Figures 17 to 27 illustrate various component parts of the pump dispenser as illustrated in Figure 1.

Description of the Preferred Embodiments

The present embodiments represent currently the best ways known to the applicant of putting the invention into practice but they are not the only ways in which this could be achieved. They are illustrated, and they will now be described, by way of example only.

Referring to Figure 1, this illustrates a lubricant dispenser 10 mounted on a rail 11. The rail has a typical profile of rails used on railway lines in the UK and abroad.

Visible in this particular illustration is a pump unit body 15 incorporating a grease or lubricant inlet 12. Grease is supplied to this inlet from a pressurised trackside reservoir. On either side of the pump unit body 15 are plunger units 16, 17 which incorporate plungers 18, 19 and grease or lubricant outlets 13, 14. The arrangement by which the lubricant dispenser 10 is mounted onto the rail will be described later.

Figure 4 illustrates in a partial cutaway form the internal workings of a plunger unit and the bolts 20A, 20B, 20C which hold the two plunger units onto the pump unit body. The operation of the plunger unit is more clearly shown in Figures 6 to 11 and in particular Figure 9. Both plunger units operate in a similar fashion.

The top of the plunger 18 extends through the top of the plunger unit such that when a train wheel passes over the track the train wheel depresses the plunger substantially into the body of the plunger unit. Mounted on the plunger is a piston 21, which is located in a close tolerance fit manner within a cylinder, bore 22. The piston/plunger components are shown in Figure 23. Grease enters the cylinder bore from the inlet 12 under pressure and in a region of the cylinder bore above the top of the piston. The passage of grease through the piston and into the main portion of the cylinder bore will be described below. The piston is biased towards an upper or "at resC position by means of a strong spring 23. As a wheel passes over the plunger, the plunger is depressed so that the piston travels down the cylinder bore 23 forcing ahead of it the slug of grease already within the cylinder. The lower position which the piston reaches is referred to as the "lubricant expelled" position. The grease ahead of the piston is forced through a non-return valve arrangement comprising a washer 24, ball 25 and spring 26. The grease exits the cylinder into an outlet means 13.

The piston incorporates certain important design features. Firstly, it contains slots 27, 28, 29 which are adapted to allow grease from the inlet into the cylinder bore on the piston upstroke. A spring-loaded non- return valve assembly protects these slots on the underside of the piston. This comprises a flexible washer 30 and spring 31, which are together mounted, on a short shaft beneath the piston. The spring or biasing means 31 exerts a lower force on the washer 30 than the force exerted by the pressurised grease reservoir on the other side of the piston. Thus, during the return stroke as the piston moves from the Iubricant expelled" to the "at resC positions, grease travels through the slots in the piston and into the cylinder bore. This operation is repeated each time the plunger is depressed, ie each time a wheel passes over the lubricant dispenser. Thus, each time the plunger is depressed a slug of grease is 6 forced out of the outlet and the volume of the bore below the piston is replenished with grease on the return stroke.

It will be appreciated that this novel arrangement of a positive displacement pump mechanism incorporated into a lubricant dispenser has a number of advantages. Firstly, all the working parts of the dispenser are bathed in grease and are thus selflubricating. No seals, other than the non-return valves, are required anywhere in the system. The plunger is a close tolerance fit within the pump unit body and that suffices to keep the grease contained within the unit. Any grease which does pass along the plunger simply serves to lubricate it. Importantly, this arrangement also minimises the possibility of air entering the system. The regions both above and below the piston are permanently swathed in grease under a positive pressure with no air present, and no possibility of air entering the system. This greatly improves the reliability of the lubricant dispenser.

The position of the piston in the "at resC position can be adjusted up or down in the cylinder bore within certain limits. In this example this adjustment is provided by a rotatable member 33, in this case a threaded stud. A spigot 34 extends from the end of the stud in an off-centre position and the stud is held in place in a threaded bore in the plunger unit by a locking nut 35. Rotation of this rotatable member through 3600 from the position shown in Figure 9 moves the plunger down to its lowest position then back up to the position shown in the figure.

This is just one mechanism by which the volume of the slug of grease can be adjusted. Another method involves operating the lubricant dispenser with only one plunger unit. Replacing one plunger unit by a blanking off end plate means that there is only one plungerlpiston assembly and one outlet. This arrangement can be used when very small dosages are required.

In the foregoing description certain terms have been used which have, in this context, a broad meaning. For example, the term non-return valve is intended to

7 encompass any type and construction of non-return valve suitable for this type of operation. Where the term "spring" is used, this is intended to encompass any form of resilient biasing means suitable for the purpose described. The terms inletloutlet means are intended to encompass both the internal passageways within the relevant unit as well as the physical inlet or outlet intended for connection to pipes leading to or from the unit. The term grease has been used in this description but it is intended that the present invention can be used to dispense any fluid including lubricants, as selected by the person skilled in the art.

The mounting means by which this lubricant dispenser is mounted onto a rail will now be described in more detail with reference to Figure 14. This illustrates a clamp 40 adapted to clamp both around and down onto the lower part of the rail. This clamp is formed from two brackets 41, 42 and connecting bolt 43. As well as clamping to the edge of the rail, the mounting means also clamps on to the top of the rail by means of bolts 44, 46 and locking nuts 45, 47. One of these clamps is provided on each side of the lubricant dispenser.

The plunger units, or the plunger unit and blanking plate, are mounted onto bolts 46 by means of mounting plates 48 which are shown more clearly in Figure 27.

These T-shaped brackets incorporate a slotted hole 49 so that the position of the plunger unit and pump body with respect to the rail can be adjusted within certain limits. By adjusting the position of nuts 50 and 51 on bolt 46 and by moving the position of the bolt 46 within the slot 49, the position of the lubricant dispenser with respect to the rail 11 can be accurately set.

This mounting means forms a second aspect of the invention and can be used to clamp other assemblies, including other lubricant dispensers onto a rail.

In summary, the device has been designed to dispense lubricant greases under pressure to lubricant dispensers specifically fabricated for Railway track maintenance. The unique design allows the volume of lubricant to be regulated to suit a

8 wide variety of applications. The positive displacement action ensures accurate dosage and no airlocks. The modular design allows a pair of plunger operated dispensers to be mounted either side of the lubricant inlet manifold. The unit can also operate with one dispenser and manifold where very small dosages are required. The manifold inlet can be either straight, angle bend or U bend, depending on the location of the lubricant reservoir.

The plunger is activated directly by a moving object passing over or being pressed against it. In most cases this will be the wheels of a train causing the plunger to be depressed. But the unit could be mounted horizontally so that pressure from say a moving rail (points) could activate the system. The plunger height/stroke can be adjusted by means of an offset crank working directly on the piston. By turning and locking the crank the offset causes the piston and connected plunger to raise or lower, allowing a measured dose for each depression of the plunger.

The piston has a built in spring loaded disc and slot valve allowing grease to pass from the upper chamber to the lower when the spring load piston/plunger is released to travel back. When the plunger is forced down the disc valve remains closed and the piston forces a slug of grease through a spring and ball non-return valve and out through the outlet port. At the same time, grease under pressure from the grease pot or reservoir, is drawn from the manifold into the upper chamber.

A special mounting cradle and clamp has been designed for the installation of the dispenser onto typical railway line rail section.

As mentioned before a single unit could be used mounted in the horizontal to provide lubrication to rail switch base plates, the unit being activated by the action of the moving rail depressing the plunger.

The unit could be made to larger dimensions if a greater dosage was required from a single activation.

9 In a further embodiment of the present intention the lubricant dispenser can incorporate a performance indicator and, optionally a communications link to a control centre. The performance indicator can take a variety of forms. For example it may consist of a pressure transducer. Pressure transducers are known per se and a 5 suitable transducer or transducers can be located at a strategic point(s) in the system. Such points include the lower region of the cylinder bore, in the outlet means andlor in the grease reservoir.

The transducer may be designed to provide a read-out of the actual pressures experienced during each depression of the piston. Alternatively the transducer and associated electronics may be set to record an alarm condition if the pressure rises above, or fails below pre-determined values.

A memory means may be provided, either at the lubricant dispenser or remotely from it. Thus memory means is adapted to keep a historic log of the pressures sensor by the transducer(s) each time the plunger is depressed. This historic log can be used to anticipate and possibly prevent fault conditions developing since a gradual deterioration in performance can be detected.

Preferably a communication link is provided to a remote monitoring point. Such communications links generally run along railway tracks at present and it is envisaged that the present invention will make use of an existing communications link.

Claims

Claims:

1. A lubricant dispenser suitable for dispensing grease, said dispenser comprising:- inlet means adapted to connect the dispenser to a lubricant reservoir; a positive displacement pump mechanism; activation means adapted to activate the positive displacement pump mechanism; (iv) outlet means adapted to direct the lubricant dispensed by the dispenser to its intended target.

2. A lubricant dispenser as claimed in Claim 1, wherein the activation means comprises a plunger and piston arrangement operating within a cylinder bore, the piston moving between an "at resC position and a Ii.ibricant expelleT position.

3. A lubricant dispenser as claimed in Claims 1 or 2, wherein the dispenser further comprises a dispenser body, said body incorporating passageways connecting the inlet means, cylinder bore and outlet means.

4. A lubricant dispenser as claimed in Claims 2 or 3, where the piston incorporates apertures adapted to allow lubricant to pass through the piston from the inlet means into the cylinder bore on the upstroke of the piston as it returns from the Iubricant expelleT position to the "at resC position.

5. A lubricant dispenser as claimed in Claim 4 wherein the apertures in the piston incorporate a first non-return valve mechanism said mechanism being biased into a closed position by a biasing means, the biasing means being adapted to allow lubricant 11 from the reservoir to enter the cylinder bore on demand whilst keeping the non-return valve closed during the down stroke of the piston.

6. A lubricant dispenser as claimed in any preceding claim, wherein the position of the piston in its "at resC position is adjustable, such that the volume of lubricant in the cylinder bore and thus the volume of lubricant available for dispensing is adjustable.

7. A lubricant dispenser as claimed in Claim 6, wherein this adjustment is provided by a moveable stop above the piston.

8. A lubricant dispenser as claimed in Claim 7, wherein this stop takes the form of an off-centre spigot in the end of a rotatable member, whereby rotating the member moves the stop up or down relative to the movement axis of the piston according to the volume of lubricant required.

9. A lubricant dispenser as claimed in Claim 5, wherein the bottom of the cylinder bore incorporates a second non-return valve mechanism, adapted to prevent lubricant propelled into the outlet means from re-entering the cylinder bore.

10. A lubricant dispenser as claimed in any preceding claim, wherein the pump dispenser is a modular assembly which comprises a pump body that is adapted to accommodate two plunger units, one on either side of the lubricant inlet.

11. A lubricant dispenser as claimed in any preceding claim, wherein the lubricant dispenser incorporates a mounting means adapted to clamp the dispenser onto a rail of a railway track.

12 12. A lubricant dispenser as claimed in Claim 10, wherein the mounting means clamps symmetrically to both sides of the rail.

13. A lubricant dispenser as claimed in Claims 11 or 12, wherein, the mounting means incorporates height and 1 or width adjustment to enable the location of the top of the plunger in relation to the top of the rail to be adjusted within certain pre-determined limits.

14. The combination of a lubricant dispenser as herein described together with a grease reservoir.

15. A lubricant dispenser incorporating a pressure transducer adapted to provide information regarding the status of the dispenser.

16. A lubricant dispenser as claimed in Claim 15, wherein the pressure transducer provides a signal indicating the pressure produced as a slug of lubricant is dispensed into the outlet means.

17. A lubricant dispenser as claimed in Claim 16, wherein the pressure transducer generates an alarm signal if the pressure during the pumping action exceeds or drops below pre-determined values.

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