US2354286A - Automatic change-over device - Google Patents

Description

July 25, 1944. T. H. WHALEY, JR ,354,2

I AUTOMATIC CHANGEOVER DEVICE Filed Sept. 14, 1942 2 Sheets-Sheet 2 INVEN'I'OR FIG. 6 v THOMAS H. WHALEY, JR.

W MW

ATTORNEYS Patented July 25,

' UNITED sTATEs PATENT OFFICE AUTOMATIC CHANGE-OVER DEVICE Thomas 11. Whaler, In, Bartlesville, kla., assignor to Phillips Petroleum Company, a corporation of Delaware Application September 14, 1942, Serial No. 458,293

This invention relates to a dispensing system for high pressure fluids and. includes a device for automatically changing withdrawal connections from a plurality of non sources;

In dispensing fluid under pressure from containers, as, for example, liquefied petroleum gas,

- spring compartments l3 and 20. Gas from thea device for automatically changing withdrawal connections from one container to another is desirable to insure an uninterrupted flow of the fluid. Various semi-automatic and fully automatic changeover devices have been proposed heretofore. The purpose of the present invention .is to provide a dispensing system including an improved fully automatic changeover device which possesses several desirable characteristics. In a system of this type, high pressure piping should preferably be avoided to insure. safety. The changeover device should withdraw gas preferentially from one container, utilizing the other as a reserve supply until the one is depleted, then automatically change to preferentially withdraw gas from the other.

An object of this invention is to provide a dispensing system for high pressure orliquefled gases.

Another object is to provide an improved container for use in such a system.

Still another object is to provide an improved inlet passages l3 and i4 is admitted to the service compartments through inlet valves 2| and 22 respectively. Each service compartment is provided with an outlet for the gas, passages 23 and 24 which join in the body member and from which the gas may flow through the passage 25 to a service line or second stage regulator. Each of the outlets 23 and 24 are provided with suitable check valves 26 and 21 to prevent back flow of gas. The poppet and spring type valves shown in the drawing are merely representative of one type which may be used, obviously any other suitable check valves may be used in these outlet passages.

The partition 29 between the two spring compartments serves to hold the springs in posidevice for efiecting a changeover of withdrawal connections.

These and other objects and advantages will be apparent from the drawings and the following detailed description.

Fig. l is a cross sectional view of one form of the changeover device.

. Fig. 2 is a cross section o a modification of the changeover device.

Fig. ,3. is a detailed showing ofan improved latch for use in the changeover device.

Fig. 4 is an elevational view of a dispensing system showing the application of the automatic I changeover and the improved container.

Fig. 5 isa fragmentary cross sectional view of a portion of the improved container form- I ing a part of this invention.

' 30 to limit the movement of the sleeve in one direction. A stem 36 is mounted within the bore of the cylindrical sleeve and slidable with respect thereto.

the stem 31 which extends within the bore of the sleeve 32 and to which is attached the piston 38, slidablewithln the bore of the sleeve. A latch is mounted in the sidewall of the sleeve Y32 and is arranged to be retracted by the guide 30. When the latching device is extended, it

cooperates with the end of stem 36 as will be de- Fig. 6 is an elevational view of a dispensing system embodying the-changeover device.

With reference; to Fig. l, the changeover de-- vice comprises a housing having a central mem- 'ber I. with two end members II and I2. Simicentral compartments will be referred to asthe lar inlet passages l3 and ll are providedin each end member tov admit'high pressure gas from two separate sources to the changeover device; Two imperforate, flexible diaphragms l5 and I6 dividethe space within the; housing into three separatesections, forming several compartments.

scribed in more detail in connection with the operation of the device. In the spring compartment 20, a spring ll is interposed between the'diaphragm i8 and the partition 23. The spring 42 in compartment I9 is interposed between the diaphragm l5 and the partition 29. A spring 43 is also contained in the spring compartment 19, between the flange 33 on the sleeve and the partition 23. All of the springs are of the compression type and oppose the gas pressure on the opposite sides of the diaphragms with which the springs areassociated. When the gas pressure in a service compartment falls below that required to overcome the opposing action of the-spring associated with the correspond- For convenience the compartments between thediaphragms and the end members will be referred to as service compartments l1 and I3, and the ing diaphragm, the inlet valve to the service compartment is opened, allowing gas to .enter the service compartment until the gas pressure therein, acting on the diaphragm, is suflicient to overcome the opposing spring action, whereupon the inlet valve is' closed.

The stem 36- is attached to the diaphragm IS. The diaphragm I6 is attachedto The spring 4| is designed to open theinlet valve 22 at a pressure higher than that atwhich the spring 42 will open the valve 2|. Consequently, with the changeover parts in the position indicated in Figure 1, gas from the inlet passage I4 is preferentially admitted to the service compartment I8 from which it passes through the passage 25 for use. When the source of supply with which the inlet passage I4 communicates is depleted, orfor any reason fails, the pressure in the service compartments I1 and I8 drops to that at which the valve 2| is opened by the action of spring 42. Gas is then supplied through the valve 2| and flows through the service compartment I1 and outlet 23 to the passage 25 at a pressure somewhat less than that at which gas was previously supplied from the service compartment I8. The action of the spring 42 in opening the valve 2| moves the stem 36 to the left. At the same time the decrease in pressure allows the spring 4| to move the diaphragm I5 to the right. The action passage I4 is replenished byreplacement of the depleted container with a filled container. When the empty container is disconnected, gas from the service compartment I8 is vented to the atmosphere through the open valve 22 and the inlet passage I4. The check valve prevents flow of gas from the outlet passage 24 to the compartment. When the pressure in the service compartment is reduced to atmospheric or thereabouts, the spring 4| will have moved diaphragm I5 to the extreme right, moving the sleeve 32 to the right and further compressing the spring 43. When the sleeve 32 is moved to the right, the latch 48 moves away from the guide 38 and drops into position behind the right end of stem 35. When a filled container is again connected to the inlet passage I4 the gas enters compartment I8 restoring pressure therein and forces the diaphragm I5 to the left against the action of the spring 4| The piston 38 then no longer bears on flange 34, and stems 38 and 31 are free to act independently. The latch 40 in extended position engages the right end of stem 38 transmitting the compressive force of the spring 43 to the diaphragm I5 to augment the action of the spring 42. The combined forces of springs 42 and 43 are greater than the force exerted on diaphragm I6 by the spring 4|. This causes the valve 2| to open and remain open until the discharge pressure built up in. the discharge conduits is sufiicient to overcome the action of springs 42 and 43. Gas is preferentially withdrawn from the container associated with the inlet conduit I3 until the supply fails. When the discharge pressure drops to that at which the spring 4] opens the valve 22, gas is again supplied from the container associated with inlet l4. when the depleted container associated with the inlet I3 is disconnected. the diaphragm I5 moves to the extreme left. This action moves the stem 33 out of engagement with the latch 40. The spring 43 moves the sleeve 32 to the left until the stop 35 engages the guide 30. At the same time, the action of the sleeve and the cooperation between the latch 48 and the guide moves the latch into inoperative position as illustrated in Figure 1. .When a full container is againconnected to the inlet I3, the diaphragm I5 is returned to the position illustrated in Figure 1, completing the cycle of operation.

With reference to Figure 2 of the drawings, a modification of the changeover device is shown. The housing comprises a central member 58, a left end member 5| and a right end member 52. The central member contains two main spring compartments 53 and 54, and two auxiliary spring compartments 55 and 56. All of the spring compartments are vented to the atmosphere through the vent hole 51. Two imperforate, flexible diaphragms 58 and 59 between the central section and the end sections separate the main spring compartments from the service compartments 50 and SI. A stem 52 is attached to the diaphragm 58. A similar stem 53 is attached to the diaphragm 58. The two stems are carried by the guides 64', 65, and 55, and are arranged to slide relative to one another through the guides; Each of the stems 62 and 53 is provided with a spring actuated latch 51 and 58 respectively, of the type commonly employed in umbrellas. At the end of stem 63 is a key 58 arranged to slide in the slot 10 of the guide 85; at the end of stem 62, the key 1| which slides in slot I2 in the guide 55. In the main spring compartment 53 is a main spring I3 which exerts a forceon the diaphragm 53 in opposition to the gas pressure in the service compartment 60. In the main spring compartment 54 a similar main spring I4 acts against the diaphragm 59. In the auxiliary spring compartments 55 and 56 are auxiliary springs I5 and 13 which are interposed between the partition 11 in the center member of the housing and the washers I8 and I9 which are slidably mounted on the stems 62 and 63. The inletpassage 8| and inlet valve 82 admit gas to the service compartment" from-which it is discharged through the outlet passages 83 and 84 to the service conduit at 85. The inlet passage 85 and inlet valve 81 admit gas to the service compartment 6| from which it is discharged through the outlet passages 88 and 34 into the service line at 85. Backflow of gas from the outlet passages 83 and 88 is prevented by suitable check valves, for example by the raised valve seats 89 and 90 which are closed by the corresponding diaphragms in extreme position to prevent flow of gas from the outlet passages to the service compartments. The valve stem 8| associated with the valve 82 cooperates with the screw 92 attached to stem 82 to open the valve 82. Similarly, the valve 81 is opened by co-action of the valve stem 93 with the screw 94 in the stem 63.

Inoperation, each of the inlet conduits 8| and 85' are connected to a.source of gas under pressure. The diaphragm 58 is acted upon by the main spring 13, and at the same time by the auxiliary spring I5. The compressive force of spring I5 is transmitted to the diaphragm 53 through the washer l8, latch 51 and stem 52. The diaphragm 59 is acted upon only by the main spring 14. It will'be at once apparent that under these conditions a lower pressure is re- ,quired to overcome the compressive force of the main spring acting on diaphragm 58' to allow associated with the inlet 8| is depleted, or fails.

to co-act with the valve stem 83 to open the valve 81 and allow withdrawal of gas from the source of supply associated with the inlet coninlet conduit 8| is disconnected, the gas from the service compartment 80 escapes to the atmosphere reducing the pressur n the service compartment. The springs 13 a d I move the diaphragm 58 and the attached'stem'fl to the left. Thekey II attached to the stem 82' engages the washer 18 moving it to the left and compressing the auxiilary spring 16. When the diaphragm 88 has moved to the extreme left position, the washer l9 uncovers the latch 68 which is extended to engage the washer. At the same time, the latch 61 is retracted by the guide 65 allowing the washer I8 to abut against the guide 85. When a full containeris again connected to the inlet passag 8|, gas enters the service compartment 88 again moving the diaphragm 58 to the right against the action of the main spring 13 only.

The auxiliary spring 16 now augments the action of the main spring I4 through washer I9, latch '68 and stem 63. Gas is, therefore, preferentially withdrawn from the source of supply'associated with the inlet passage 86 until that supply fails or becomes exhausted. When the container associated with the inlet passage 86 is disconnected, the gas from compartment 6| escapes to the atmosphere lowering the pressure therein. The diaphragm 59 is moved to the extreme right by the action of the springs I4 and I6. Thisaction moves the stem 63 to \the right whereupon the key 69 contacts the Washer 18 moving the washer to the right compressing the auxiliary spring to the position shown in Figure 2. The latch 61 is extended to engage the Washer 18. Simultaneously, the latch 68 'is retracted by the action of the guide 66 allowing th washer I9 to abut against guide 66. When a full container is again connected to the inlet passage 86, the pressure is restored in compartment 6| returning the diaphragm and stem to the position shown in Figure 2, thereby completing the cycle.

A unique feature of the automatic changeover of my invention is that the characteristics of the changeover mechanism are not affected by a temporary cessation ofthe gas supply. Gas is preferentially withdrawn from a designated container until that container is disconnected from the system. At that time, a change in the operating mechanism takes place to allow preferential withdrawal from the opposite container until it is depleted. Therefore, if freezing of a container occurs during service, withdrawal of gas duit 86. When the container connected to the ders I03 engage the washer associated-with the auxiliary spring when the latches are in extended position. The latching mechanism is compact,

requiring little space, and is not affected by ordinary wear. The camming surfaces are so designed that wear on the pins 91 or bumpers IIII will not materially affect the position at which the latches are retracted. The two shoulders I83 on opposite sides of the stem take the thrust of the auxiliary springs (15, 16) against th stems (82, 63).;

With reference to Figure 4, a system is shown in which the automatic changeover mechanism of Figure 2 is used with improved containers formwith the customary safety devices, not shown in I the drawings. The gas outlet is through an opening H2 in the top of the container. Attached to the top of the container over the opening and forming a part thereof is a shield II3 forming a part of thhe container and having an outlet closed by the valve tap plug H4. The tap plug is protected by the rim II5 of the shield; A conventional guard ring H8 maybe provided to protect the shield and cylinder head from damage.

from that container continues as soon'as the pressure in the container is restored to the pressure at which the changeover device discharges. This pressure is preferably 'much reduced from the normal container pressure. Hence, the containers are rather completely emptied. Any suitable indicator may be used to indicate that a container has been depleted and should be replaced by a filled container.

Figure 3 shows an improved latching mechanism in which an opposed pair of identical latches 86, pivoted on the pins 91, are mounted in a recess 88 in the stem which attaches to the diaphragms in Figure 2. The latches are provided with bumpers IIII, camming surfaces I02 and shoulders I83. The latches are urged apart by the spring I84 held in position by the pin I05. The bumpers IIlI limit the extended position of the latches. The camming surfaces I02 engage the guides to retract the latches, while the shoul- When placed in service the two containers are placed on a suitable support II! with the tap plugs turned toward one another. The two con tainers may then be coupled to the changeover device by means of the couplings H8 and without the necessity of using flexible conduits subjected to'the high gas pressures. Couplings which are self-aligning are suitable for use. Such couplings have previously been devised and need no further description. The valved tap plugs and couplings discolsed by R. W. Thomas in Patents Nos. 2,172,310 and 2,172,311 may be used as the tap plugs H4 and couplings IIB.

Figure 6 shows the automatic changeover device used in a conventional liquefied gas dispensing system. Liquefied gas in the containers I and 2 is vaporized and the gas is delivered through the high pressure conduits 3 and 4 to the changeover device-of my invention designated generally by the numeral 5. Gas passing the changeover device is delivered to the service conduit 6. If desired, a gas pressure regulator I may be inter-.

pdsed in the service line 6.

While'I have sho specific embodiments of my invention'various hanges may be resorted to. particularly changes in the valves associated with the changeover device, and changes in the size, shape, and relative positions of parts without departure from the spirit of my invention.

I claim:

1. In aliquefied gas system,- a completely automatic changeover valve mechanism for the purposes described, comprising in combination a body provided with a valved inlet port for each of two supply sources, a pressure responsive diaphragm associated with each 'of said valved ports, a pressure chamber formed by each of said diaphragms on their inlet sides, a channel communicating each of said pressur chambers to a c mmon outlet, back-flow check valves in each controllable by said diaphragms and said main loading springs to alternately apply and remove the loading of said auxiliary loading spring to and from one of said 'diaphragms.

2. In a liquefied gas system, a fully automatic device for exchanging delivery of gas fromone source of supply to another comprisin a body fitted with a valved inlet for each of said supply sources, pressure responsive means for operating each of said valves independently of the other, means for loading each of said responsive means to a dissimilar extent, auxiliary resilient means in a part of said body, and means for alternately engaging and disengaging said auxiliary loading means with and from the pressure responsive means associated with the lesser of the recited dissimilar, loading means upon predetermined movement of said pressure responsive means.

In a device of the class described for dispensing liquefied petroleum gases, the organization which comprises a housing containing a pair of axially opposed diaphragms, an apertured wall therebetween, a spring loading one of the diaphraghm away from said wall, a second spring of lesser strength loading the second ,diaphragm away from said wall, a sleeve portion projecting axially from the periphery of said aperture, a sliding member movable axially in said sleeve, a third spring loading said sliding member in the direction of the second recited diaphragm, a loading element attached to said second diaphragm and extending slidably within said sliding member, a motivating member having lostmotion engagement with saidsliding member and attached to the first of said diaphragms, and a latch member carried by said sliding member, said latch member being arranged so as to be retracted when disposed within said sleeve Po tion and extensible to engage said loading element when withdrawn from said sleeve and beyond the end of said loading element.

4. In a liquefied gas system, a fully automatic changeover device of the class described comprising a body provided with a pair of inlet passages discharging to a common outlet, a valve in each of said inlets for reducing the pressure of fluid flowing therethrough, a diaphragm operatively associated with each of said valves, a pair of springs of equal strength, each loading one of said diaphragms in a valve-opening direction, a second pair of springs of lesser strength than the first said pair but equal in strength to eachother, and automatic means controlled by movement of said diaphragms to place said auxiliary prings singly and alternately in augmentive relationship with the respective springs of the first-mentioned pair.

5. In a. liquefied gas system, a fully automatic changeover device of the class described comprising in combination a housing, valved inlet ports formed in the walls of said housing for connection of two sources of fuel under pressure, a pressure responsive element associated with each of said inlet valves, a pressure chamber defined between each said diaphragm and its associated inlet port, a channel communicating each of said chambers to a common outlet, a back-flow check valve in each of said channels, a primary resilient member associated with the unpressured side of each diaphragm, a secondary resilient member for each of said diaphragms, and latching means operable to alternately bias the resilient loading of the respective diaphragms by sequential engagement and disengagement of the respective secondary resilient members therewith. 6. In a changeover device for liquefied gas systems of the class described, the organization which comprises a case containing a pair of axially'opposed diaphragms, a pair of apertured walls in said case between the diaphragms, a main loading spring associated with each diaphragm for loading the same away from the nearest of said walls, an apertured central wall between the said pair of walls, a separate loading shaft attached to each of said diaphragms and supported by the said walls within their apertures, said shafts being slidable in said apertures and relative to each other, a pair of sliding members ene'ageable with said shafts, a pair of auxiliary springs, each loading one of said sliding members away from said central wall, and latching members carried on each of said shafts for engagement with said sliding members.

7. In a liquefied gas system, a changeover device comprising a body member having a gas outlet and gas inlets to accommodate two sources of gas supply. a valve controlling the flow of gas to each of said inlets, valve operating means associated with th valves to operate one valve in preference to the other until a minimum discharge pressure is reached at the gas outlet and then to operate the other valve, and means responsive to predetermined movement of said valve operating means to change the operation of said valve operating means to open the other valve in preference to the first mentioned valve until a minimum discharge pressure is reached and then to open said first mentioned valve.

8. In a liquefied gas system, a changeover device comprising a body member having agas out let and gas inlets to accommodate two sources of gas supply, valves to control the flow of gas through each of said gas inlets, gas pressure responsive means operating each of said valves in response to the pressure at the gas outlet, means for resiliently loading each of said gas pressure responsive means in opposition to the pressure at the gas outlet, and means responsive to predetermined movement of said pressure responsive means to alternately increase and decrease the loading on at least one of said pressure responsive means.

9. In a liquefied gas system, a. changeover device comprising a body member having a gas Outlet and as inlets to accommodate two sources of gas supply, valves to control the flow of gas through each of said gas inlets, gas pressure responsive means operating each of said valves, means for resiliently loading each of. said pressure responsive means, and means responsive to predetermined. movement of said pressure responsive means to supplement the loading of at least one of said pressure responsive means.

till

an auxiliary loading spring for supplementing the loading on one of said diaphragms,.and means responsive to predetermined movement of said diaphragms for alternately engaging and disengaging said auxiliary spring.

- THOMAS H. WHALEY, JR.

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