Fluid isolator

Abstract

2021200865 11 Feb 2021 5 15 FOAS FILE REF:5489C-AU 10 20 21 20 08 65 1 1 Fe b 20 21 2021200865 11 Feb 2021 TS G1 GN P1 PN T FC-1 FC-N 1o in 2 CV-1 CV-N 2a 2n A B B M T a T TP1 TP2 R P P FIG. 2 15

Description

FLUID ISOLATOR Field of the Invention The present invention relates to fluid isolators and hydraulic or pneumatic systems incorporating fluid isolators. In particular the present invention relates to the fluid isolator and hydraulic system disclosed in Australian Patent No 2013 308 381. Background Art The specification of the above-mentioned Australian patent discloses a fluid isolator for use in the hydraulic system of machinery used in various technology areas such as mining, construction and agriculture. In particular, the fluid isolator has a manually activated bleed valve which is intended to be operated when the hydraulic system needs to be depressurised so as to ensure safety of personnel during maintenance or servicing, Genesis of the Invention However, it would be desirable to enable the hydraulic system to be depressurised under various predetermined conditions, such as in the event of a fire. It is towards the achievement of such an arrangement that the present invention finds its Genesis. Summary of the Invention In accordance with a first aspect of the present invention there is disclosed a fluid isolator comprising: a primarily outlet port adapted to be coupled to a hydraulic device; a first bleed valve having a first position and a second position; a first fluid line in fluid communication with the primary outlet port and the bleed valve; a first one way valve located in the first line, the first one way valve inhibiting the flow of fluid towards the primary outlet port; a second one way valve located in the first line, the second one way valve inhibiting the flow of fluid toward the primary outlet port; a primary gauge port adapted to be coupled with a pressure gauge; a second line in fluid communication with the primary gauge port and a portion of the first line located between the first one way valve and the second one way valve; said first bleed valve being switchable between the first position and the second position to permit the flow of fluid from the primary outlet port to a region of lower fluid pressure; and a second bleed valve connected in parallel with said first bleed valve, said second bleed valve being actuatable by an electric circuit having a sensor arranged to detect a predetermined condition. Preferably a delay is incorporated and the predetermined condition is a fire. In accordance with a second aspect of the present invention there is disclosed an hydraulic system comprising: a fluid isolator as referred to above; a fluid reservoir in fluid communication with said first bleed valve; a pump in fluid communication with said fluid reservoir; a control valve in fluid communication with said pump; an accumulator in fluid communication with said control valve and one of the primary or secondary outlet ports of the fluid isolator; an hydraulic device in fluid communication with the control valve; and a line extending between one of said primary or secondary outlet ports of the fluid isolator and a line extending between the control valve and the hydraulic device. According to another aspect of the present invention there is provided a method of protecting from fire an item of machinery having the hydraulic system as defined above and an onboard fire deluge system, said method comprising the steps of: following the detection of the fire by said on board fire deluge system, depressurising the machinery hydraulic system, and delaying said depressurising by a time delay sufficient to permit a machinery operator to place said item of machinery in a park condition. Brief Description of the Drawings A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 substantially reproduces Fig. 5 of the above-mentioned patent and illustrates the provision of a timer switch TS, and Fig. 2 is substantially reproduces Fig. 1 of the above-mentioned patent and illustrates the provision of a second bleed valve. Detailed Description As seen in Fig. 1, an hydraulic system 1 includes an hydraulic cylinder 2, a control valve 4, a pump 5, a tank 6 and an accumulator 8, all of which are substantially conventional. The pump 5 pressurises hydraulic fluid from the tank 6 and supplies same to the control valve 4 to permit operation of the cylinder 2. As in the above- mentioned patent, an hydraulic isolator 10 is connected to the lines interconnecting the cylinder 2, valve 4 and accumulator 8 as well as to the tank 6. A person skilled in the art needs no further explanation of the hydraulic system 1 and the hydraulic isolator 10, however, an interested reader can find further details in the specification of the above-mentioned patent. The hydraulic system 1 is installed on a machine such as a bulldozer or front end loader, or the like, which also has a substantially conventional fire deluge system to guard against fire engulfing the machine. Such a fire deluge system has a conventional burn cable which is triggered in the event of a fire, or heat sufficient cause a fire, and thus acts as a triggering sensor to initiate the fire deluge system. As seen in Fig. 1, in accordance with the preferred embodiment a conventional automatic timer switch TS is connected between the fire deluge system and the isolator 10. Turning now to Fig, 2, the interior of the isolator 10 is illustrated. The isolator 10 has a multiplicity of pressure ports P1 - PN each of which is connected to a corresponding pair of check valves in the form of a first check valve FC and a second check valve CV. A corresponding one of a multiplicity of gauge ports G1 - GN is connected to the junction of the corresponding pair of check valves. As in the above-mentioned patent, a first manually operated bleed valve 14 is provided in the isolator 10. In addition, a second, solenoid operated bleed valve 15 is connected in parallel with the valve 14. The timer switch TS is connected to the solenoid of the valve 15. In operation, incoming hydraulic fluid under pressure from a machine circuit flows through one of the pressure ports P1 - PN through the corresponding one of the first check valves FCI - FCN and then through the corresponding one of the second check valves CV1 - CVN. Simultaneously this hydraulic fluid flows through porting between the two check valves to the corresponding one of the gauge ports G1 - GN which provides an individual test port for incoming pressure. From the second check valve the hydraulic fluid flows into the common gallery P (indicated on the valves 14, 15). The common gallery P has two drillings TP1 and TP2 which enable the connection of test gauges, remote gauges, pressure sensors, and the like, so as to measure the pressure of the common gallery P. The common gallery P is also connected to both valves 14 and 15. Both valves 14 and 15 have three outlet ports. Outlet port B is blocked by use of the dead head whilst ports R and A are connected to the tank 6 (Fig. 1. An operator, for example during maintenance, can operate the valve 14 as explained in the above-mentioned patent in order to reduce the pressure in the common gallery P and thus throughout the hydraulic system generally. However, in the event of an emergency situation, such as a fire, then the operation of the deluge system commences. This is immediately apparent to the operator. Under these circumstances, the operator of the machine has a short delay time (e.g. 1 - 5 minutes) determined by the timer switch TS within which to place the machine into a safe “park” condition before the valve 15 operates to reduce the pressure on the common gallery P. The foregoing describes only one embodiment of the present invention and modifications, obvious to those skilled in the hydraulic arts, can be made thereto without departing from the scope of the present invention. For example, whilst the sensor initiating operation of the timer switch TS is the burn cable of a fire deluge system, the invention is not restricted only to such systems and can be initiated by other sensors of other systems such as collision avoidance systems. The term “comprising” (and its grammatical variations) as used herein is used in the inclusive sense of “including” or “having” and not in the exclusive sense of “consisting only of”,

Claims

CLAIMS 1. A fluid isolator comprising: a primarily outlet port adapted to be coupled to a hydraulic device; a first bleed valve having a first position and a second position; a first fluid line in fluid communication with the primary outlet port and the bleed valve; a first one way valve located in the first line, the first one way valve inhibiting the flow of fluid towards the primary outlet port; a second one way valve located in the first line, the second one way valve inhibiting the flow of fluid toward the primary outlet port; a primary gauge port adapted to be coupled with a pressure gauge; a second line in fluid communication with the primary gauge port and a portion of the first line located between the first one way valve and the second one way valve; said first bleed valve being switchable between the first position and the second position to permit the flow of fluid from the primary outlet port to a region of lower fluid pressure; and a second bleed valve connected in parallel with said first bleed valve, said second bleed valve being actuatable by an electric circuit having a sensor arranged to detect a predetermined condition.

2. The fluid isolator as claimed in claim 1 further comprising one or more secondary outlet ports, two and additional hydraulic device; a third line extending between each said secondary outlet port and the first line between the second one way valve and said first bleed valve; a third one way valve located in the third line, the third one way valve inhibiting the flow of fluid toward the secondary outlet port; a fourth one way valve located in the third line, the fourth one way valve inhibiting the flow of fluid toward the secondary outlet port; a secondary gauge port adapted to be coupled with a pressure gauge; and a fourth line in fluid communication with the secondary gauge port and a portion of the third line located between the third one-way valve and the fourth one way valve. 3, The fluid isolator as claimed in claim 1 or 2, wherein a first test port is located in the first line between the second one way valve and said first bleed valve. 4, The fluid isolator of claim 3, were in a second test port is located in the first line between the second one way valve and said first bleed valve.

5. The fluid isolator as claimed in any one of claims 2-4 were in the primary and secondary gauge ports are double check valves, 6. The fluid isolator as claimed in any one of the preceding claims wherein said first bleed valve is a direction control valve.

7. The fluid isolator as claimed in claim 6 wherein said first bleed valve is a four port two position direction control valve.

8. The fluid isolator as claimed in any one of the preceding claims wherein said first bleed valve is manually operable.

9. The fluid isolator as claimed in any one of claims 1-7 wherein said first bleed valve includes a solenoid and is electrically operable.

10. The fluid isolator as claimed in any one of claims 2-9 further comprising a manual control to selectively provide fluid communication with the primary gauge port and the secondary gauge port.

11. The fluid isolator as claimed in claim 10 wherein the manual control is a button, knob or lever.

12. The fluid isolator as claimed in any one of claims 1-11 wherein a time delay switch is connected between said sensor and said second bleed valve to delay actuation of said second bleed valve for a predetermined time until after detection of said predetermined condition.

13. The fluid isolator as claimed in claim 12 wherein said time delay is sufficient to allow a machinery operator to place the machinery in a park condition prior to actuation of said second bleed valve.

14. The fluid isolator as claimed in claim 12 or 13 wherein said sensor is a heat sensor and said predetermined condition is a fire.

15. An hydraulic system comprising: a fluid isolator as claimed in any one of claims 1-14; a fluid reservoir in fluid communication with said first bleed valve; a pump in fluid communication with said fluid reservoir; a control valve in fluid communication with said pump; an accumulator in fluid communication with said control valve and one of the primary or secondary outlet ports of the fluid isolator; an hydraulic device in fluid communication with the control valve; and a line extending between one of said primary or secondary outlet ports of the fluid isolator and a line extending between the control valve and the hydraulic device.

16. A method of protecting from fire an item of machinery having a hydraulic system as defined in claim 15 and an onboard fire deluge system, said method comprising the steps of: following the detection of the fire by said onboard fire deluge system, depressurising the machinery hydraulic system, and delaying said depressurising by a time delay sufficient to permit a machinery operator to place said item of machinery in a park condition. FRASER OLD & SOHN Patent Attorneys for the Applicant

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