US3583421A

US3583421A - Pressure failure warning system

Info

Publication number: US3583421A
Authority: US
Inventors: E James Treloar
Original assignee: ROGAR PRODUCTS Ltd
Current assignee: ROGAR PRODUCTS Ltd
Priority date: 1969-05-22
Filing date: 1969-05-22
Publication date: 1971-06-08
Anticipated expiration: 1988-06-08
Also published as: DE2024643B2; JPS4931496B1; DE2024643A1

Abstract

A valve, especially useful to anaesthetists, for warning of the existence of a low pressure in a main supply and to transfer to a reserve supply upon the existence of a lower main supply pressure.

Description

United States Patent E. James Treloar Vancouver, British Columbia, Canada 826,984 May 22, 1969 June 8, 1971 Rogar Products Ltd.

Vancouver, British Columbia, Canada Inventor Appl. No Filed Patented Assignee PRESSURE FAILURE WARNING SYSTEM 7 Claims, 6 Drawing Figs.

U.S. C1 137/113, 1 37/1 1 1 Int. Cl 605d 16/06 Field of Search 137/1 14,

[56] References Cited UNITED STATES PATENTS 3,033,220 5/1962 St Clair 137/557- 3,342,201 9/1967 Grogono 137/112 3,351,088 11/1967 Jensen 137/557 Primary Examiner-Laverne D, Geiger Assistant Examiner-William H. Wright Attorney-Fetherstonhaugh & Co.

ABSTRACT: A valve, especially useful to anaesthetists, for warning of the existence of a low pressure in a main supply and to transfer to a reserve supply upon the existence of a lower main supply pressure.

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PATENTEU JUN 8197i SHEET 2 UF 3 PATENTED JUN 8197i SHEET 3 OF 3 mvlm'rou E. JAMES TRELOAR ATTORNEYS PRESSURE FAILURE WARNING SYSTEM BACKGROUND OF THE INVENTION This invention is concerned with a device for warning that a gas supply is at or below a predetermined pressure and for automatically switching to a reserve supply at that or another predetermined pressure.

The invention has particular but not necessarily exclusive, application in monitoring and controlling gases such as for example oxygen, used while administering anesthetics Whilst the invention does not seek to completely relieve the anesthetist of the responsibility of maintaining a constant and careful watch on the supply of gases to the machine from which the gases are administered to the patient it is a system which effectively will give a warning of a low level of gas supplied to the machine. It will also effectively save on gas wastage by allowing supply cylinders to be emptied to a greater extent than was hitherto considered safe.

BRIEF SUMMARY OF THE INVENTION According to one aspect of this invention there is provided a warning system which has a main gas supply and a reserve gas supply with a common gas outlet. Valves are arranged in the supplies such that when the pressure in the main supply falls to a certain level a valve is actuated to direct gas from that supply not only to the outlet but also to a pressure actuated warning device, such as a whistle. When the pressure falls to a lower predetermined level or even at about the same time with the opening of the first valve, the supply is switched from the main to the reserve but the warning signal is maintained by gas pressure from the reserve supply and that warning signal is only stopped when the main supply is restored to a pressure above the higher of the predetermined levels as by replacing the main cylinder.

From another aspect of the invention there is provided a valve comprising a main supply inlet, a reserve supply inlet, an outlet and an outlet adapted to be connected to an audible signal device and a valve element responsive to main supply pressure and adapted to connect the reserve supply to the signal outlet upon the existence ofa predetermined low pressure. Preferably the valve element also connects the reserve supply to the outlet up on the existence of that predetermined low pressure.

In one embodiment there is provided a valve comprising a main supply inlet, a reserve supply inlet, an outlet and a supply to an audible signal device in which the reserve supply inlet is connected to the outlet through a first valve element and said main supply is connected through an open passage to the outlet and to said audible signal supply through a second valve element, both sad valve elements being adapted to be operated in response to pressures, said second valve being opened at a higher pressure that said first valve so that when main supply pressure falls to the first predetermined low level the main supply is connected both to the outlet and to the audible signal supply and upon main supply pressure reaching the lower of the low levels the reserve is connected to the outlet and to the audible signal supply.

It is preferred according to this invention to arrange that main supply pressure is exerted on one side of a diaphragm to the other side of which a spring-loaded valve operating ele ment is located so that when the pressure on the supply side of the diaphragm falls the valve operating member is moved to open an appropriate valve.

Conveniently there can be a pressure guage located to indicate outlet pressure.

DESCRIPTION OF THE FIGURES OF THE DRAWINGS An embodiment of the invention is illustrated schematically in the accompanying drawings:

FIG. 1 is a front view of the device of this invention,

FIG. 2 is a side view, partly broken away of the device in Figure 1,

FIG. 3 is a section on the line 3-3 of FIG. 2,

FIG. 4 is a front view ofthe device with parts removed,

FIG. 5 is a section on the line 5-5 of FIG. 4, and

FIG. 6 is a section on the line 6-6 of FIG. 4. DESCRIPTION OF A PREFERRED EMBODIMENT The device comprises a front section 10 which houses the controls and a rear section in which the valves are located and at which the connections of hoses to the cylinders and machines are made.

The front section of the device comprises a box the front face on which is an operating knob 31 and a window 32 through which a scale, to be described hereinafter, may be seen.

Within the box there is a gear 33 which is fixed on the shaft 34 of the operating knob 31. The gear 33 meshes with gear 38 which in turn meshes with gear 35. Gear 35 has a coaxial pinion 36 which meshes with a gear 37 which carries the scale which can be viewed through the window 32.

It will be appreciated that as the operating knob 31 is turned so are

gears

33 and 36.

The spindle of the knob extends completely through the housing 10 and into a tubular section 40. There are two such tubular sections 40 one containing the spindle of the operating knob 31 and the other containing a similar spindle which is mounted on the gear 35. Each of the spindles terminates in a screw threaded section and each of those screw threaded sections carries a threaded abutment piece only one of which can be seen in FIG. 2 and which is numbered 42. The abutment pieces 42 each carry a radial projection 43 which moves in a guide formed in the sidewall of the tubular section 40 to preclude rotation of the abutment piece with the spindle. In this way rotation of the operating knob causes the abutment piece on each of the spindles to move along those spindles towards or away from the operating knob.

Coaxial with each of the spindles are springs 44 of which one end of each is in abutting relationship with the appropriate one of the abutment pieces 42. The other ends of the springs act on valve operating members 45 so that the springs are compressed between the abutment members 42 and the valve operating members 45. The valve operating members are secured to corresponding diaphragms 46 which are trapped between the section 20 and the annular flanges 46 of the tubular sections 40. The operating members 45 have annular grooves defined by

shoulders

47 and 48 within which the diaphragms and an appropriate stiffening member is located.

Referring now to FIG. 4, 5 and 6 in which the valve section of the device is illustrated it will be seen that it comprises a block in which there is formed a main inlet passage 50, a reserve inlet passage 51 and an outlet passage 52 with which

sections

53 and 54 of inlets and 51 respectively communicate. Outlet is indicated on an appropriate pressure guage 55 which is connected to the outlet through a passageway 56. The inlet 50 has a branch 57 which communicates with an appropriate waring device such as for example, a whistle.

Referring now specifically to FIG. 6 there is a cylindrical chamber 60 which is divided by a partition 61 into two

sections

62 and 63. The section 62 is closed by the diaphragm 46 on the operating knob spindle and the section 63 is closed by a threaded closure 64 and an appropriate O"-ring 65. The inner end of the closure 64 is recessed as at 66 to accommodate a spring 67 which acts between the base of the recess 66 and a valve member 68. The valve member 68 is provided with an annular flange 69 and a locating pin 70 which is coaxial with the spring 67 and serves to properly locate that spring. The valve acts to seal an opening through the partition 61 and has an O-ring 72 which cooperates with the marginal edges of defining the opening through the partition. Extending through the opening in the partition is an operating rod 73 which cooperates with the front face of the operating member 45 so that as the spring 44 urges the operating member 45 towards the valve member, and against the action of gas pressure on the diaphragm, the valve is opened and as the operating member is moved in the opposite direction then the valve is closed.

Referring now to FIG. 5 the structure is basically similar to that illustrated in FIG. 6 except that the inlet section 51 opens into the section of the chamber on the valve side of the partition and the section 54 of the inlet opens into the opposite side of the partition. For the sake of convenience, the similar parts of the valve illustrated in FIG. 5 to those of the valve illustrated in FIG. 6 are alloted similar reference numerals and are distinguished by the addition of the letter a.

The operation of the device is as follows. The valves 68 and 68a are adapted to be opened at different pressures, the valve 68 being operated at a higher pressure than the valve 68a. The springs 44 are precompressed by rotation of the operating knob to the desired setting which will be reflected in the window 32 for example, the valve 68 can be set to be opened at a pressure of say, 30 pounds whilst the valve 680 will automatically be set to open at a pressure of say pounds per square inch. The higher pressure is the one at which the whistle is connected and the lower the one at which the reserve supply is opened.

When the device is operating normally with the main supply of gas at a high pressure then the flow will be through the

inlet

50, 53 to the outlet 52 with the outlet pressure being indicated on the guage 55. Both the valves will be closed so that there will be no flow to the whistle nor from a reserve supply to the line 51.

When the pressure in line 50 falls to a preset level then the pressure in chamber 62, which is exerted upon the diaphragm will lessen and the spring 44 associated with that diaphragm will cause it to move and with it the valve operating member 45, to raise the valve 68 from the seat and allow the passage of gas through passage to sound the whistle. At the same time the gas will continue to flow through passage 53 of the main inlet to the outlet 52 thence for example, to service outlets.

It is usual for the connection to the main inlet 50 to be made through a T-joint so that there be two cylinders or supplies to the main inlet and as the whistle sounds the anesthetist will open the second main cylinder but in the event that he is otherwise occupied with more immediately urgent tasks and the pressure in the main supply falls below another and related low level then the pressure in section 6211 of chamber 61a will correspondingly fall until the spring associated with the diaphragm at that chamber will move forward, and with it will move the valve 68a to allow the reserve supply to flow through

passages

51, 54 and through to the outlet 52. At the same time there will be flow from the reserve supply to passage 53 to maintain the whistle sounding.

The whistle will continue to sound until a full cylinder, or a cylinder above the first predetermined level of pressure is put onto the main line.

It is to be appreciated that the device according to this invention is simple and effective and whilst it is not intended to relieve the anesthetist of the principal responsibility for maintaining the supply it is to a very large extent foolproof.

Further, in many applications the alarm signal and transfer pressures can be preset so the operating knob and associated gearing can be omitted in those cases.

I claim:

I. A valve comprising a main supply passage, a reserve supply passage, an outlet passage and a supply passage to an audible signal device, said reserve passage being connected to the outlet passage and to the signal supply passage through a first valve and said main passage being connected through an open passage to the outlet passage and to said audible signal supply passage through a second valve element, said second valve element being opened upon the existence of a first low pressure and said first valve element being opened upon the existence of a lower pressure than first low pressure.

2. A valve as claimed in claim 1 in which said valve elements are opened by spring loaded valve actuator members, the opening movement of said actuator members being opposed by main supply line pressure. g

3. A valve as claimed In claim 2 in which the valve actuator members are carried by diaphragm on one side of which springs act and the other sides of which are exposed to main supply line pressure.

4. A valve as claimed in claim 2 in which the lengths of the springs are adjustable to vary the force exerted upon the actuator members.

5. A valve as claimed in claim 3 in which the lengths of the springs are adjustable to vary the force exerted upon the actuator member.

6. A valve as claimed in claim 2 in which the length of the springs are adjustable to vary that force exerted upon the ac tuator members, and there is a single control for varying the lengths of both springs simultaneously.

7. A valve as claimed in claim 3 in which the length of the springs are adjustable to vary that force exerted upon the actuator members, and there is a single control for varying the lengths of both springs simultaneously.

Claims

1. A valve comprising a main supply passage, a reserve supply passage, an outlet passage and a supply passage to an audible signal device, said reserve passage being connected to the outlet passage and to the signal supply passage through a first valve and said main passage being connected through an open passage to the outlet passage and to said audible signal supply passage through a second valve element, said second valve element being opened upon the existence of a first low pressure and said first valve element being opened upon the existence of a lower pressure than first low pressure.

2. A valve as claimed in claim 1 in which said valve elements are opened by spring loaded valve actuator members, the opening movement of said actuator members being opposed by main supply line pressure.

6. A valve as claimed in claim 2 in which the length of the springs are adjustable to vary that force exerted upon the actuator members, and there is a single control for varying the lengths of both springs simultaneously.