GB2096320A - Lubricant tank - Google Patents

Abstract

A tank (10) for holding a lubricant is provided with a removable dipstick (26). The dipstick (26) is retained within the inner of two concentric tubes (14, 15), the inner tube (14) being capable of sliding movement within the fixed outer tube (15). The arrangement is such that when the dipstick (26) is inserted into the inner tube (14), port apertures (34) and a vent aperture (35) within the inner tube (14) allow lubricant to flow therein. When the dipstick (26) is removed for lubricant level checking, the inner tube (14) slides, due to spring (24), to cause the outer tube (15) to obturate the apertures (34) and the tank top (11) to obturate the vent aperture (35) and thereby prevent the leakage of lubricant from the tank via the inner tube (14). <IMAGE>

Description

SPECIFICATION Lubricant tank This invention reiates to tanks suitable for holding a lubricant and in particular to tanks which are provided with a dipstick adapted to indicate the level of lubricant within the tank.

Tanks suitable for holding a lubricant are frequently provided with a dipstick in order that the level of lubricant within the tank may be checked. If the tank in question is pressurised or liable in use to aiterations in its attitude, it is necessary to ensure that a seal is provided between the dipstick and the tank in order to prevent any loss of lubricant. Moreover suitable locking means are usually necessary to ensure that the the dipstick is not lost in the event of pressure within the tank ejecting the dipstick during attitude changes. However after the lubricant level has been checked using the dipstick, it sometimes happens that the dipstick is not correctly re-positioned and locked in the tank.

If such incorrect re-positioning and locking is not noticed, lubricant leakage can occur and the dipstick may be lost. Complete loss of the dipstick could be very serious since it may result in very rapid loss of all of the lubricant contained within the tank.

It is an object of the present invention to provide a lubricant tank having a dipstick, which tank is so adapted as to prevent the leakage of lubricant therefrom in the event of said dipstick being incorrectly positioned in said tank or in the event of said dipstick being absent from said tank.

According to the present invention, a tank suitable for holding a lubricant is provided with a removable dipstick, support means projecting into the interior of said tank and adapted to receive and enclose said dipstick, and means adapted to retain said dipstick in position within said support means, said support means being provided with port means adapted to be open when said dipstick is retained in position within said support means, but which is otherwise closed, said port means being arranged such that when open, a portion of the lubricant contained within said tank passes therethrough into said support member, said support member having vent means so arranged that when said port means is open, the level of lubricant within said support member is equal to that of the lubricant remaining within said tank.

Thus when the dipstick is subsequently removed from the support member, the port means will close to prevent the loss of lubricant from the tank and the lubricant level indicated on the dipstick will be equal to the level of lubricant within the tank.

The support member preferably comprises two concentric tubes, one a sliding fit within the other, the outer tube being open at both ends and fixed in relation to said tank, the inner tube being closed at one end and adapted to receive and enclose said dipstick at the other end, said port means being located in said inner tube and adapted to be opened and closed by relative sliding movement between said inner and outer tubes, said relative sliding movement being caused in turn by the insertion and removal of said dipstick into and out of said inner tube.

Said port means preferably comprises at least one aperture in said inner tube, said at least one aperture being obturated by said outer tube when said dipstick is not retained within said inner tube, relative sliding movement between said inner and outer tubes resulting from the insertion of said dipstick into said inner tube being such as to cause said inner tube to translate to a position where said at least one aperture is not so obturated by said outer tube.

Said inner tube is preferably provided with spring biassing means to cause it to translate relative to said outer tube upon the removal of said dipstick from said inner tube to a position where said at least one aperture is obturated by said outer tube.

Said tank is preferably provided with duct means adapted for the removal of lubricant from said tank, said duct means being interconnected with the interior of said inner tube via said vent means when said dipstick is retained in position within said inner tube.

Said vent means is preferably obturated when said dipstick is removed from said inner tube.

Said vent means is preferably so positioned as to be obturated by a portion of said tank when said inner tube slides relative to said outer tube upon the removal of said dipstick from said inner tube.

Said dipstick is preferably retained in position in said inner tube by locking means provided on said tank.

The invention will now be described, by way of example, with reference to the accompanying drawings in which Figure 1 is a sectioned side view of a tank in accordance with the present invention, its dipstick having been removed, Figure 2 is a sectioned side view of a tank in accordance with the present invention, with its dipstick retained in position.

With reference to Figure 1 a tank 10 which is suitable for holding a lubricant is provided with an enlarged top portion 11 which serves to enclose the tank 10 and aiso support a duct 12 for the withdrawal of lubricant from the tank 10 and a dipstick support member 13.

The dipstick support member 13 comprises two vertical concentrically mounted tubes 14 and 1 5. The outer tube 1 5 is rigidly attached to the tank top 11 at 16 and is open at both its upper and lower ends 17 and 18. The inner tube 14 is smaller than the outer tube 1 5 and is mounted for sliding movement within both the outer tube 1 5 and a portion of the tank top 1 The vertically upper end 1 9 of the inner tube 14 is slidingly located within a generally annular member 20 which is in turn located in the tank top 11. More specifically the upper end 1 9 of the inner tube 14 is outwardly flared to define a flange 21 which bears against the wall of the bore 22 of the annular member 20.The annular member 20 is also provided with a flange 23 at the lower end of the bore 22 which bears against and guides the inner tube 14. The flanges 21 and 23 additionally serve as location features for a compression spring 24 which is interposed between them.

Thus the compression spring 24 tends to urge the inner tube 14 in generally upward direction.

Movement of the inner tube 14 in an upward direction is limited by sealing plate 25 which is provided at its lower end. The sealing plate 25 is fixedly attached to the inner tube 14 so as to seal its lower end and is additionally of greater diameter than the outer tube 1 5 so as to sealingly locate against the lower end 18 of the outer tube 15 and thereby limit upward movement of the inner tube 14.

It will be seen therefore that when the inner 14 is positioned as shown in Figure 1, the only route which lubricant can follow to leave the tank 10 is through the outlet duct 12.

The level of lubricant within the tank 10 is checked using a dipstick 26 which can be seen in Figure 2. Thus the dipstick 26 comprises a handle 27 to which is attached a blade 29. The dipstick 26 is located in the dipstick support member 13 by inserting the dipstick blade 29 into the inner tube 14 until a shoulder 30 on the dipstick handle 27 locates against the flange 21 on the upper end of the inner tube 14. The dipstick 26 is then pushed against the compression spring 24 until radial pins 31 provided on the dipstick handle 27 can be located in bayonet slots 32 provided within the annular member 20. Thus the spigots 31 and bayonet slots 32 serve to lock the dipstick 26 in position in the inner tube 14.

The action of pushing the dipstick 26 against the compression spring 24 serves to slide the inner tube 14 downwards within the outer tube 1 5 so that the sealing plate 25 no longer engages the lower end 18 of the outer tube 15 and a portion 33 of the inner tube 14 projects from the lower end 18 of the outer tube 15. The portion 33 of the inner tube 14 which projects from the lower end 18 of the outer tube 1 5 is provided with a number of ports defined by apertures 34.

When the inner tube 14 is in the position shown in Figure 1, i.e. when the dipstick 26 is not in position, the port apertures 34 are obturated by internal wall of the outer tube 15. However when the dipstick 26 is locked in position as shown in Figure 2, the port apertures 34 are not so obturated and consequently lubricant contained in operation within the tank 10 is free to flow into the interior of the inner tube 14. Escape of oil from the inner tube 14 4 to the tank exterior is prevented by two sealing rings 26a provided below the spigots 31 on the dipstick handle 27.

The portion of the inner tube 14 which passes through the tank top 11 is provided with a further aperture 35 which can be seen in Figure 1. The aperture 35 is a vent which is obturated by the tank top 11 when the inner tube 14 is in the position shown in Figure 1. However when the dipstick 26 is locked in position as shown in Figure 2, the vent aperture 35 is aligned and in communication with a chamber 36 which is within the tank top 11. The chamber 36 is in turn in communication with the lubricant outlet duct 12 via a passage 37 within the tank top 11.

It will be seen therefore that when the dipstick 26 is locked in position as shown in Figure 2, the vent aperture 35 will permit lubricant to flow through the port apertures 34 and rise to a level within the inner tube 14 which is equal to that of the lubricant remaining within the tank 10.

Subsequent removal of the dipstick 26 for inspection of the lubricant level results in the inner tube 14 sliding upwards under the influence of the compression spring 24 until the sealing plate 25 engages the lower end 18 of the outer tube 1 5. This has the effect of obturating the port apertures 34 and the vent aperture 35, thereby preventing the escape of oil from the tank 10 through the dipstick support member 13.

Claims (9)

Claims

1. A tank suitable for holding a lubricant, said tank b'eing provided with a removable dipstick, support means projecting into the interior of said tank and adapted to receive and enclose said dipstick, and means adapted to retain said dipstick in position within said support means, said support means being provided with port means adapted to be open when said dipstick is retained in position within said support means but which is otherwise closed, said port means being arranged such that when open, a portion of the lubricant contained within said tank passes therethrough into said support member, said support member having vent means so arranged that when said port means is open, the level of lubricant within said support means is equal to that of the lubricant remaining within said tank.

2. A tank as claimed in claim 1 wherein the support member comprises two concentric tubes, one a sliding fit within the other, the outer tube beirg open at both ends and fixed in relation to said tank the inner tube being closed at one end and adapted to receive and enclose said dipstick at the other end, said port means being located in said inner tube and adapted to be opened by relative sliding movement between said inner and outer tubes, said relative sliding movement being caused in turn by the insertion and removal of said dipstick into and out of said inner tube.

3. A tank as claimed in claim 2 wherein said port means comprises at least one aperture in said inner tube, said at least one aperture being obturated by said outer tube when said dipstick is not retained within said inner tube, relative sliding movement between said inner and outer tubes resulting from the insertion of said dipstick into said inner tube being such as to cause said inner tube to translate to a position where said at least one aperture is not so obturated by said outer tube.

4. A tank as claimed in claim 3 wherein said inner tube is provided with spring biassing means to cause it to translate relative to said outer tube upon the removal of said dipstick from said inner tube to a position where said at least one aperture is obturated by said outer tube.

5. A tank as claimed in any one of claims 2 to 4 wherein said tank is provided with duct means adapted for the removal of said lubricant from said tank, said duct means being interconnected with the interior of said inner tube via said vent means when said dipstick is retained in position within said inner tube.

6. A tank as claimed in claim 5 wherein said vent means is obturated when said dipstick is removed from said inner tube.

7. A tank as claimed in claim 6 wherein said vent means is so position as to be obturated by a portion of said tank when said inner tube slide relation to said outer tube upon the removal of said dipstick from said inner tube.

8. A tank as claimed in any one preceding claim wherein said dipstick is retained in position in said inner tube by locking means provided on said tank.

9. A tank substantially as hereinbefore described with reference to and as shown in the accompanying drawings.