GB2220515A

GB2220515A - Indicating device

Info

Publication number: GB2220515A
Application number: GB8816333A
Authority: GB
Inventors: Christopher Derrick Gray
Original assignee: COMMAND HYDRAULICS Ltd
Current assignee: COMMAND HYDRAULICS Ltd
Priority date: 1988-07-08
Filing date: 1988-07-08
Publication date: 1990-01-10
Also published as: GB8816333D0

Abstract

An indicating device 10 in a pressure-activated warning device 14 comprises an indicator 12 having at least first and second distinct visible codings, e.g. green and red markings 34, 36 indicating first and second conditions in an apparatus (50, 52). The device further comprises a fibre optic element 22 having a first end 30 arranged in optical communication with one of the codings 34, 36 on the indicator 12. The indicator 12 is movable relative to the first end 30 of the optical element 22 whereby an operator 42 viewing a second end 38 of the element can determine the condition of the apparatus (50, 52). The indicating device is especially useful with oil filter assemblies (54) employing differential pressure warning devices (14, 14') Fig 6 (not shown) to indicate when a change of oil filter is needed. In another embodiment, Fig 3 (not shown), a second fibre optic element (22') is employed to direct light from, for example, a miner's helmet lamp to the device. <IMAGE>

Description

INDICATING DEVICE This invention relates to an indicating device. The invention also relates to multiple indicating assemblies, pressure activated warning devices and filter assemblies which incorporate an indicating device.

Filter assemblies are provided on most types of apparatus which utilise oil in their operation; the oil is usually for providing lubrication and transmitting power. The filter assemblies serve to take impurities out of the oil. In order to ensure that the oil is effectively filtered the filter in the filter assemblies must be changed from time to time. Otherwise the filter clogs to an unacceptable level, and this reduces the effectiveness with which the oil is filtered, and increases the pressure drop across the filter.

Thus, it is important to know when the filter needs to be changed. There are warning devices available to indicate when the filter needs - changing. These are pressure activated devices which use the increase in pressure to indicate when the filter needs changing: when the pressure increases above a particular value a movable member is ejected from the warning device to indicate that the filter needs changing.

However, the movable member is not easily visible.

Moreover, there can be several filter assemblies on a single apparatus and some of these may not be visible; this problem is especially acute with apparatus used in underground mining where the filter assemblies may be between the apparatus and a wall of the tunnel.

In order to solve this problem electrical and electronic warning systems have been devised. However, these systems are expensive, particularly in mining applications where strict safety requirements have to be met.

It is an object of the invention to provide a simple and effective indicating device.

It is a particular object of the invention to provide an indicating device which can be used in filter assemblies, and in underground mining applications.

According to a first aspect of the invention there is provided an indicating device comprising an indicator having at least a first coding indicating a particular condition in an apparatus, and a fibre optic element, wherein said indicator is movable relative to a first end of the fibre optic element between a first position in which the fibre optic element is in optical communication with the coding to indicate the presence of the condition in the apparatus, and a second position in which the fibre optic element is out of optical communication with the coding to indicate the absence of the condition in the apparatus, whereby an operator viewing a second end of the fibre optic element can determine the presence or absence of the condition in the apparatus.

The indicating device is preferably adapted to be secured to the apparatus. To this end, a housing is preferably provided which is adapted to be secured to the apparatus. The housing may house the indicator and hold the first end of the fibre optic element in position.

Desirably the indicator is movable relative to the fibre optic element and the housing.

The particular condition of the apparatus may be undesirable so the indication of the presence of the condition indicates that remedial action must be taken.

Advantageously the indicator is provided with a second coding indicating the presence of a further particular condition in the apparatus, wherein the first end of the fibre optic element is in optical communication with the second coding when the indicator is in the second position. The further condition may be another undesirable condition, or may be the normal operating condition which indicates no remedial action need to be taken.

When the first end of the fibre optic element is in optical communication with the first coding, then the operator, looking at the second end of the fibre optic element will see substantially only the first coding. It is possible that part of the second coding may be visible, but a sufficient part of the first coding should be visible for the operator to know that the apparatus is in the first condition. Similar considerations app;y when the fibre optic element is in optical communication with the second coding. It will be appreciated that the important point is that the operator should be able to deduce the condition of the apparatus from an inspection of the second end of the fibre optic element.

In underground mining applications, or other applications where the apparatus is in darkness, it is necessary to provide a light source to illuminate the indicator. In underground mining the light source can advantageously be provided by the lamp on the miner's helmet. When an additional light source is used, it is advantageous to provide a second fibre optic element, whereby a light source can be placed adjacent the second end of the second fibre optic element, and the first or second visible codings can be viewed from the second end of the first fibre optic element.

Desirably a lens is disposed adjacent the second end of the or each fibre optic element. This helps. to make the first or second codings appear more clearly to the operator.

The or each visible coding may be any form of marking which can distinguish a particular condition of the apparatus. Preferably the or each visible coding comprises first and second areas on the indicator having first and second colours respectively.

In one embodiment the indicator comprises a tubelike member, wherein the first and second areas may comprise adjacent bands of said first and second colours on said tube.

Typically the first coding indicative of the first condition would be red coloured and the second coding indicative of the second condition would be green coloured. Thus, if the operator views the green coding at the second end of the fiber optic element he knows that the apparatus is functioning normally, and if he views the red coding, he knows that the apparatus is not functioning normally.

Preferably the indicator is adapted to be secured to a movable part of the apparatus.

According to another aspect of the invention there is provided an indicating device comprising indicator having at least first and second distinct visible codings indicating respectively first and second conditions in an apparatus, and a fibre optic element, the fibre optic element having a first end thereof arranged in optical communication with one of the distinct codings of the indicator, wherein said indicator is movable relative to the first end of the fibre optic element, whereby an operator viewing a second end of the fibre optic element can determine the condition of the apparatus.

According to another aspect of the invention there is provided a multiple indicating assembly comprising a plurality of said indicating devices each adapted to be secured to different parts of the apparatus, or to different apparatuses, and a viewing unit which houses the second ends of the fibre optic elements.

According to another aspect of the invention there is provided a pressure actuated warning device comprising a movable member said member being movable from a first position to a second position in response to pressure in the device rising above a preselected value, and an indicating device as described above.

The pressure actuated warning device may for example be a differential pressure warning device of the type manufactured by Pall Industrial Hydraulics Ltd, and sold under the trade name DELTADYNE-.

The indicator of the indicating device is secured to the movable member.

According to a further aspect of the invention there is provided a filter assembly provided with a pressure activated warning device as described above.

The indicating device according to the invention can effectively indicate when an apparatus is functioning abnormally.

The indicating device is purely mechanical, and requires no electrical or elecronic components, so it is completely safe to use in hazardous atmospheres, such as in underground mining.

The indicating device provides a remote indication of the condition of the apparatus, so it is possible to determine the condition of parts of the apparatus which are otherwise not readily visible.

Reference is now made to the accompanying drawings in which: Figures 1 and 2 are cross-sections of one embodiment of an indicating device according to the invention in first and second positions respectively; Figure 3 is a cross-section of another embodiment of indicating device in a second position; Figures 4 and 5 are cross-section of another embodiment of an indicating device according to the invention in first and second positions respectively; and Figure 6 is a schematic view showing a multiple indicating assembly according to the invention.

Referring to figures 1 and 2 an indicating device generally designated 10 is secured to a differential pressure warning device 14. The warning device 14 may, for example, be of the type manufactured by Pall Industrial Hydraulics Limited of Portsmouth, England, and sold under the trade name DELTADYNE. The device 14 can be used with all the filters manufactured by Pall Industrial Hydraulics Limited.

The warning device 14 is connected to apparatus 50 or 52 which includes at least one filter assembly 54 (see figure 6). The warning device 14 includes a movable member 16 which is activated in response to the pressure in the filter assembly 54. The movable member 16 is movable between a first position (as shown in figure 1) and a second position (as shown in figure 2); in the first position, the movable member 16 extends beyond an outer surface 18 of the device 14.

The indicating device 10 includes an indicator 12, a housing 20 and a fibre optic element 22.

The housing 20 comprises a substantially cylindrical member having a closed end 24 and an open end 26 which receives and is secured to the warning device 14. The housing 20 has an opening 28 which receives a first end 30 of the fibre optic element 22; the fibre optic element 22 is secured to the housing 20.

The indicator 12 is in the form of a tube secured at one end to the movable member 16. The other end of the indicator 12 extends through an aperture 32 in the closed end 24 of the housing 20.

The indicator 12 is provided with a first visible coding in the form of a marking 36 in a first area thereof, and a second visible coding in the form of a marking 34 in a second area thereof. The first and second areas comprise adjacent bands on the tube of the indicator 12. Typically the first visible marking 36 comprises a red colouration, and the second visible marking 34 comprises a green colouration.

The fibre optic element 22 also includes a second end 38 having a lens 40 disposed adjacent thereto, so that an operator 42 can view the second end 38 through the lens 40.

In operation the indicator 12 is movable with the movable member 16. When the filter assembly 54 is operating normally the indicator 12 and movable member 16 are in the second position indicated in figure # with the first end 30 of the fibre optic element 22 in optical communication with the green marking 34. When the operator 40 looks into the second end 38 of the fibre optic element 22 through the lens 40 he will view the green marking 34. This will tell the operator that the filter assembly 54 is operating normally.

When the filter of the filter assembly 54 becomes clogged with impurities the pressure drop across the filter increases. When the pressure drop reaches a preselected value, the movable member 16 is activated and moves to the right, to the position shown in figure 1.

The indicator 12 moves with the movable member 16 so that the red marking 36 is brought into optical communication with the first end 30 of the fibre optic element 22.

If the operator 40 looks into the second end 38 of the fibre optic element 22 through the lens 40, he will now view the red marking 36. This will tell the operator that the filter needs to be changed.

When the indicating device 10 is used in applications where there is little or no illumination (such as in underground mining), it is clearly necessary to provide a light source to illuminate the markings 34 and 36 (unless some form of luminescent markings are employed).

In these circumstances a light source could be provided, for example, within the housing 20. In underground mining applications, however, it is unnecessary to provide a light source in the housing because every miner carries a light on his helmet; this light source can be used to illuminate the green and red markings 34 and 36 through the fibre optic element 22.

In the application of the indicating device 10 to underground mining it is preferred to use the embodiment shown in figure 3. The parts in figure 3 are similar to the parts in figures 1 and 2; like parts have been designated with like reference numerals.

In figure 3 the indicating device 10' includes an additional fibre optic element 22' having a first end 30' and a second end 38'. The fibre optic elements 22 and 22' are disposed in a large aperture 28' provided in the housing 20.

A lens 40' is disposed adjacent the second end 38' of the fibre optic element 22' so that light from a light source 44 can travel through the lens 40' to the second end 38'. The light from the light source 44 travels along the fibre optic element 22' to shine on the green or red marking 34 or 36. The green or red markings 34 or 36 are read by the operator 42 using the fibre optic element 22.

In underground mining, the light source 44 can be conveniently provided by the lamp on the operator's helmet.

Another embodiment of indicating device is shown in figures 4 and 5. The indicating device 10" shown in figures 4 and 5 is similar to the device 10 shown in figure 1 and 2, and like parts have been designated with like reference numerals.

In figure 5 the warning device 14" is of a type manufactured by FAIREY ARLON and sold under the trade name FAIREY ARLON. The device 14" is for use with filter assemblies manufactured by FAIREY ARLON under the designation "visual indicator".

In the embodiment of figure 5, the indicator 12" comprises solely the first visible coding in the form of marking 36" and the second visible coding in the form of marking 34". In figure 5 the red marking 36" is not visible because it is disposed adjacent the green marking 34" within a warning device housing 16a".

The markings 34" and 36" can be provided on a tube fitted over the movable member 36" or may comprise a thin coating printed over the surface of the movable member 36".

The housing 20" is provided with a closed end 24" and an open end 26" which receives and is secured to the warning device 14". The housing 20" also includes an aperture 28" to which the first end 30 of the fibre optic element 22 is secured.

The operation of the indicating device 10" is similar to the operation of the indicating device 10.

Figure 5 shows the indicating device 10" with the indicator 12 in the position indicating normal operation of the filter assembly 54; figure 4 shows the indicating device 10" with the indicator 12 in the position indicating that the filter of the filter assembly 54 needs changing.

It will be appreciated that the indicating device 10" can be provided with two fibre optic elements 22 and 22' in a similar manner to the indicating device 10'.

Figure 6 shows a multiple indicating assembly according to the invention. It should be stressed that the components shown in figure 6 are shown schematically only, and should not be considered to represent the actual shape or relative dimensions thereof.

In figure 6 two apparatuses are shown designated 50 and 52. The apparatus 50 is provided with two filter assemblies 54, and the apparatus 52 is provided with three filter assemblies 54. Each filter assembly 54 is provided with one of the warning devices 14 and the indicating devices 10'. It will be appreciated that the filter assemblies 54 could be provided with the warning devices 14", or with the indicating devices 10' or 10".

The second ends 38 and 38' of the fibre optic elements 22 and 22' are each connected to a single viewing unit 56. Thus, the condition of each of the filter assemblies 54 can be checked by an operator simply by viewing the single viewing unit 56. It will be appreciated that more filtering assemblies 54, and more apparatuses 50 and 52 can be used.

Claims

1. An indicating device comprising an indicator having a first visible coding indicating a particular condition in an apparatus, and a fibre optic element, wherein said indicator is movable relative to a first end of the fibre optic element between a first position in which the fibre optic element is in optical communication with the first visible coding to indicate the presence of the particular condition, and a second position in which the fibre optic element is out of optical communication with the first visible coding to indicate the absence of the particular condition, whereby an operator viewing a second end of the fibre optic element can determine the presence or absence of the particular condition in the apparatus.

2. An indicating device according to claim 1, wherein said device is adapted to be secured to the apparatus.

3. An indicating device according to claim 1 or 2, further comprising a housing adapted to be secured to the apparatus, wherein said housing houses the indicator and holds the first end of the fibre optic element in position.

4. An indicating device according to claim 3, wherein the indicator is movable relative to the fibre optic element and the housing.

5. An indicating device according to any of claims 1 to 4, wherein said indicator further includes a second visible coding distinct from the first visible coding, and when said indicator is in the second position the first end of the fibre optic element is in optical communication with the second visible coding.

6. An indicating device according to any of claims 1 to 5, wherein a second fibre optic element is provided, whereby a light source can be placed adjacent the second end of the second fibre optic element, and the first or second visible codings can be viewed from the second end of the first fibre optic element.

7. An indicating device according to any preceding claim, wherein a lens is disposed adjacent the second end of the or each fibre optic element.

8. An indicating device according to any preceding claim, wherein the first and second visible codings comprise first and second areas on the indicator having first and second colours respectively.

9. An indicating device according to any preceding claim, wherein the indicator comprises a tube-like member.

10. An indicating device according to claims 8 and 9, wherein the first and second areas comprise adjacent bands of said first and second colours on said tube.

11. An indicating device according to any preceding claim, wherein the indicator is adapted to be secured to a movable part of the apparatus.

12. An indicating device substantially as. herein described with reference to and as shown in the accompanying drawings.

13. An indicating device comprising an indicator having at least first and second distinct visible codings indicating respectively first and second conditions in an apparatus, and a fibre optic element, the fibre optic element having a first end thereof arranged in optical communication with one of the distinct codings of the indicator, wherein said indicator is movable relative to the first end of the fibre optic element, whereby an operator viewing a second end of the fibre optic element can determine the condition of the apparatus.

14. A multiple indicating assembly comprising a plurality of indicating devices according to any preceding claim, each device being adapted to be secured to a different part of the apparatus, or to different apparatuses, and a viewing unit which houses the second ends of the or each fibre optic element.

15. A multiple indicating assembly substantially as herein described, with reference to and as shown in figure 5.

16. A pressure actuated warning device comprising a movable member said member being movable from a first position to a second position in response to pressure in the device rising above preselected value, and an indicating device according to any of claims 1 to 13, wherein the indicator of the indicating device is secured to the movable member.

17. A filter assembly provided with a pressure activated warning device according to claim 16..