GB2139081A

GB2139081A - Cleaning tanks and holds of ships

Info

Publication number: GB2139081A
Application number: GB08310685A
Authority: GB
Inventors: Raymond Flanagan
Original assignee: SI JET Ltd
Current assignee: SI JET Ltd
Priority date: 1983-04-20
Filing date: 1983-04-20
Publication date: 1984-11-07
Also published as: GB2139081B; EP0167685A1; GB8310685D0; EP0167685B1

Description

1

SPECIFICATION

Fixture for thermostatically mixing hot and cold water The present invention relates to an improvement in a fixture for mixing hot and cold water from hot-and cold-water pipes so as to automatically regulate the temperature of hot water discharged from a faucet.

The Japanese Laid-open Patent Publication 57-127171 discloses a known fixture of this type in which when a temperature sensing element senses a difference between the tem- perature of hot water and that of cold water, a 80 valve is actuated thereby so as to control the temperature of hot water discharged from a faucet. Fig. 2 of this publication is included as Figs. 9 and 10 in the accompanying draw- ings, in which a valve casing 50 includes a cold-water supply chamber 52, a hot-water supply chamber 51 which is partitioned from the cold-water supply chamber 52 by a partition wall 66, a mixed-water chamber 53, and an elongate tubular body 54 which is journailed within the mixed-water chamber 53. The left end of the elongate tubular body 54 constitutes a valve seat 56 through which cold water is admitted into the body 54 from the cold-water supply chamber 52. A blank cap 59 is screwed into a tapped hole 58 provided in the side wall of the hot-water supply chamber 51. The inner end of the blank cap 59 constitutes a valve seat 57. A hole 63 provided in the partition wall 65 serves as a valve guide for a stubby control valve 60 which is interposed between the valve seats 56 and 57. A casing 61 Which accommodates a temperature sensing element 64 fits in the elongate tubular body 54. A hole 62 provided off-center in the left end wall of the casing 61 is in alignment with one of a plurality of holes 55 provided in the hub of the control valve 60 so that when the left annular surface of the control valve 60 is detached from the valve seat 57, hot water may be allowed to flow from the hot-water supply chamber 51 into the casing 61 so as to come in contact with the temperature sens- ing element 64.

This prior art fixture has a disadvantage that during the passage of hot and cold water therethrough, the control valve 60 is apt to be pushed toward the low-pressure side. This is caused by the fact that there is a difference between the diameter D of the hole 63 and the diameter D, of the circles formed by both ends of the control valve 60 on one hand, and by the fact that the control valve 60 is stubby on the other hand.

The above-described prior art fixture has another disadvantage that the temperature sensing element 64 is not sensitive enough and it takes so much time for the control valve to regulate the flow rate that a great loss 130

GB 2 139 324A 1 of water is incurred. Such a low sensitivity is caused by the water current running slowly through an excessively large space T left between the internal surface of the casing 51 and the external surface of the temperature sensing element 64.

The present invention seeks to provide a fixture which eliminates the above-mentioned disadvantages.

In one aspect the invention provides a fixture for thermostatically mixing hot and cold water from hot- and cold-water pipes, comprising a hot-water supply chamber to which hot water is fed from said hot-water pipe, a cold-water supply chamber to which cold water is fed from said cold-water pipe, a mixed-water chamber commucicating with said two chambers and formed coaxially therewith, a valve chest accommodated in said hot- water supply chamber and said cold-water supply chamber and communicating with these two chambers through a hot-water inlet and a cold-water inlet, respectively- a main valve and a control valve slidably accommo- dated in said valve chest, an elongate tubular body is accommodated in said mixed-water chamber and connected with said valve chest, one end of said elongate tubular body which is disposed within said valve chest being formed into a valve seat on which said control valve is adapted to rest, and a casing slidably fitting in said elongate tubular body and accommodating a temperature sensing element.

In another aspect the invention provides a fixture for thermostatically mixing hot and cold water from hot and cold- water pipes, comprising a hot-water supply chamber for receiving hot Water from the hot-water pipe, a cold-water supply chamber for receiving cold water from the cold-water pipe, a mixed-water chamber communicable with the hot and coldwater supply chambers, a control valve slidably accommodated in a valve guide and movable in response to a temperature sensing element to control the temperature of water supplied to the mixed-water chamber, the control valve having at each of two opposite ends an annular seal the mean diameter of which is equal to the inside diameter of the valve guide.

Thus it is possible to free the control valve from differential pressure which would cause a movement of the control valve toward the low-pressure side and to adapt the control valve for accurately cutting off the discharge of water and preventing the leakage.

In yet another aspect the invention provides a fixture for thermostatically mixing hot and cold water from hot and cold-water likes, comprising a hot-water supply chamber for receiving hot water from the hot-water pipe, a cold-water supply chamber for receiving cold water from the cold-water pipe, a mixed water chamber communicable with the hot and coldwater supply chambers, a control valve sli- 2 GB 2 139 324A 2 dably accommodated in a valve guide and movable in response to a temperature sensing element to control the temperature of water supplied to the mixed-water chamber, the temperature sensing element being mounted in a casing such that there is a space between the temperature sensing element and the casing through which water flows from the hot and cold water supply chambers to the mixed- water chamber, said space being so narrow as to be adapted to allow the temperature sensing element to quickly respond to a change in water temperature.

A preferred embodiment of the present in- vention is hereinafter described with reference to the accompanying drawings, in which:

Fig. 1 is a partially cutaway plan view of a fixture in accordance with the present inven tion; Fig.2 is a vertical sectional front view 85 thereof, Fig. 3 is a sectional view taken along line 111-111 of Fig. 1; Fig. 4 is a sectional view taken along line IV-IV of Fig. 2; Fig. 6 is a sectional view taken along line VV of Fig. 2; Fig 6 is an enlarged sectional view of a control valve in accordance with the present invention; Fig. 7 is a side view thereof, Fig. 8 is an enlarged, partially cutaway perspective view of a casing which accommodates a temperature sensing element in accor- dance with the present invention; Fig. 9 is a horizontal sectional view of a prior art fixture; and

Fig. 10 is an enlarged view of a part thereof.

Referring now to Figs. 1 to 5, a fixture in accordance with the present invention includes a valve casing in which a hot-water supply chamber 2, a cold-water supply chamber 3 and a mixed-water chamber 4 are formed coaxially with one another and partitioned from one another by inward flanges 28. Hot water is fed to the hot-water supply chamber 2 through a hot-water passageway 8 which communicates with the chamber 2 by a hot-water inlet 5. Cold water is fed to the 115 cold-water supply chamber 3 through a coldwater passageway 9 which communicates with the chamber 3 by a cold-water inlet 6. The hot- and cold-water passageways 8 and 9 are partitioned from the chambers 2, 3 and 4 by a partition wall 10 in such a manner that the passageways 8 and 9 run parallel with the chambers 2, 3 and 4 in the axial direction of the valve casing 1. The downstream portions of the passageways 8 and 9 lie one upon 125 another as shown in Fig. 3.

A valve chest 24 in which a main valve 17 and a cylindrical control valve 18 are slidably accommodated, fits in the inward flanges 28.

Hot water flows from the hot-water supply chamber 2 into the valve chest 24 through a hot-water inlet 5, while cold water flows from the cold-water supply chamber 3 into the valve chest 24 through a cold-water inlet 6 The right-hand end of the valve chest 24 is provided with a screw thread 42, and a cap nut 19 is screwed on the screw thread 42 (Figs. 1 and 2). A valve spindle 23 extends through a hole axially provided in the center of the cap nut 19. One end of the valve spindle 23 is screwed into a tapped hole 43 axially provided in the main valve 17, while the other end of the valve spindle 23 is provided with a knob 38. By turning the knob 38, the main valve 17 can be axially moved so as to be pressed against the control valve 18. Thus the knob 38 can be used for manually interrupting the flow of water.

The left-hand end of the valve chest 24 is connected with the right-hand end of an elongate tubular body 11 which extends through the mixed-water chamber 4 (Figs. 1 and 2). The end of the tubular body 11 disposed within the valve chest 24 is formed into a valve seat 13 on which the control valve 18 is adapted to rest. The tubular body 11 has an outward flange 41. A plug 16 is threaded into the left-hand end of the casing 1 so as to press the outward flange 41 against an annu- lar shoulder formed by the extreme left inward flange 28 as viewed in Fig. 1. The tubular body 11 extends further leftwardly through the plug 16. The portion of the tubular body 11 projecting from the plug 16 is provided with a screw thread 44, and a cap nut 33 is screwed on the screw thread 44. A spindle 23 extends through a hole axially provided in the center of the cap nut 33. The external end of the spindle 23 is coupled with a knob 38 by means of a spline 35, while its internal end is coupled with a plug 45 by means of a spline 36, The plug 45 is threaded into the tubular body 111 An apertured washer 21 is seated in the left-hand end of the control valve 18 in Fig, 2, and a spring 22 engages at opposite ends against the washer 21 and an annular shoulder 21 provided in the main valve 17 so as to bias the control valve 18 against the valve seat 13, Referring now to Figs, 2 to 7, the control valve 18 is provided with an annular seal 15 on the side facing the main valve 17 and another annular seal 15 on the side facing the valve seat 13. The diameters D of the annular axes of the seals 15 and 15 are equal to the external diameter of the control valve 18.

A plurality of holes 14 are provided in the control valve 18 in parallel with the axis thereof so that while the annular seal 15 is apart from the main valve 17, hot water may be allowed to flow from the hot-water supply chamber 2 into the casing 26 through the hot-water inlet 5 and the holes 14. Likewise, while the annular seal 15 is apart from the valve seat 13, cold water is allowed to flow 3 GB 2 139 324A 3 from the cold-water supply chamber 3 into the casing 26 through the cold- water inlet 6 Referring now to Figs. 2 and 8, a casing 26 slidably fits in the elongate tubular body 11 and accommodates a temperature sensing ele- 70 ment 30 which is filled with a liquefied or gaseous temperature sensing medium. The casing 25 is provided with a plurality of projections 27 on the side facing the control valve 18 so as to allow a plurality of recesses 27 to alternate with the projections 27. The recesses 27 serve to allow the temperature sensing element 30 to be highly sensitive in the early stage of a change in the water temperature. One end of the temperature sensing element 30 projects from the casing 26 so that when the annular sea[ 15 abuts the valve seat 13, the end of the temperature sensing element 30 may slightly come into the control valve 18. The water current runs through a narrow space 29 left between the internal surface of the casing 26 and the external surface of the temperature sensing element 30 and flows out of the casing 26 through outlets 40, such water current being indicated by the arrow P3 in Fig. 8. The throttling effect of the casing 26 serves to allow the temperature sensing element 30 to be highly sensitive. For example, thae internal diameter of the casing 26 may be 13mm and the external diameter of the temperature sens ing element 30 may be 9mm, leaving there between an annular gap having a width of 2mm.

A push rod 31 is adapted to operate the casing 26. The plug 45 is provided with a bore in which a disc 32 with a cupped surface for holding against the left-hand end of the push rod 31 is axially slidable. The disc 32 is biased to the right by a spring 22. This spring 105 operates in opposition to the spring 22, and the two springs normally hold the control valve 18 in balance. This balance is adapted to be upset when the temperature sensing element 30 works in response to a change in 110 the temperature of water passing through the space 29. The control valve 18 is actuated thereby to regulate the flow rates of hot and cold water. The numeral 34 designates a push button for a safety device (not shown).

The parts normally occupy the positions shown in Fig. 2. Hot water is fed to the hotwater supply chamber 2 through the hotwater passageway 8 and hot-water inlet 5, flows from the chamber 2 into the valve chest 24 through the hot-water inlet 5 and then into the casing 25 through the holes 14, keeps in contact with the surface of the temperature sensing element 30 while running through the narrow space 29, flows from the casing 25 into the mixed-water chamber 4 through the outlets 40 provided in the casing 25 and through outlets 40 provided in the elongate tubular body 11, and is discharged from a faucet 39.

The temperature sensing element 30 quickly works when it senses a change in the temperature of hot water which is being supplied to the mixedwater chamber 4 through the space 29. Then the temperature sensing element 30 expands toward, and gives a push to, the control valve 18. Then the space between the control valve 18 and the main valve 17 is narrowed, while the annular seal 15 of the control valve 19 is detached from the valve seat 13. Consequently, cold water which has flowed from the cold-water supply chamber 3 into the valve chest 24 through the coldwater inlet 5, is allowed to flow into the casing 25 and mixed with the hot water during passage through the space 29. Then the mixed water flows from the casing 25 into the mixed- water chamber 4 through the outlets 40 and 30, and is discharged from the faucet 39.

During the time when the annular seal 15 of the control valve 18 is only slightly apart from the valve seat 13, cold water flows into the casing 25 through the recesses 27 so that a drop in the water temperature caused by the inflow of the cold water may be sensed by the temperature sensing element 30 at an early stage of the temperature drop. Then the temperature sensing element 30 contracts and thereby regulates the space between the control valve 18 and the main valve 17 so that hot water with a moderate temperature will be discharged from the faucet 39.

The above-described temperature control is facilitated by the facts that the casing 25 and the temperature sensing element 30 are resiliently biased to the right by the spring 22 and that the spring 22 operates in opposition to'the spring 22 so as to resiliently hold the control valve 18 i n balance.

If fine control is desired, the knob 38 is manipulated so as to screw the plug 45 inwardly. Then the spring 22 is compressed and comes to apply pressure to the casing 25 and the temperature sensing element 30 through the disc 32 and the push rod 31 so as to reduce the range within which the control valve 18 can move.

In order to decrease the flow rate of hot water discharged from the faucet 39, the knob 38 is manually operated so as to narrow the space between the control valve 18 and the main valve 17.

In order to interrupt the flow of water, the knob 38 is manipulated so as to move the main valve 17 leftwardly as viewed in Fig. 2. Then the main valve 17 is pressed against the control valve 18 so that hot and cold water will be intercepted on the outsides of the 12 5 annular seals 15 and 15, respectively.

The present invention has the following advantages:

(1) The place where the hot water is intercepted is kept separate from the place where the cold water is intercepted. This construc- - 1 4 GB 2 139 324A 4 tion precludes the possibility that the cold water, which has a higher inlet pressure than the hot water, flows backward into the water heater and thereby incurs a heat loss and/or 5 puts out the pilot burner.

(2) Both Sides of the control valve 18 are under an equal water pressure, because the diameters D of the annular axes of the seals 15 and 15 are equal to the external diameter of the control valve 18. Thus the control valve 18 is free from differential pressure which would cause a movement of the control valve 18 toward the low-pressure side and make it difficult for the fixture to maintain a preset temperature.

(3) If a deposit is formed on, or a foreign substance sticks to, the surfaces of the main valve 17, control valve 18 and/or valve seat 13 so much as to hinder the fine control of hot water temperature, such a deposit or foreign substance can be washed off by manipulating the knob 38 so as to reciprocate the main valve 17 several times during the discharge of hot water from the faucet 39.

(4) Because of the provision of recesses 27 and narrow space 29, the temperature sens ing element 30 is adapted to-quickly respond even to an abrupt manipulation of the knob 38 so as to assure smoothness in effecting the temperature control.

(5) As compared with the conventional fix tures, there is no possibility that the knobs 38 and 38 are operated in a wrong manner.

Simple construction of the fixture in accor dance with the present invention increases the productivity and drastically decreases distribu tion costs such as transportation and packag ing costs.

While a preferred embodiment of the pre sent invention has been disclosed, it is to be understood that it is described by way of example only and not in a limiting sense and the scope of the present invention is deter mined by the following claims.

Claims

1. A fixture for thermostatically mixing hot and cold water from hot- and cold-water pipes, comprising a hot-water supply chamber to which hot water is fed from said hot-water pipe, a cold-water supply chamber to which cold water is fed from said cold-water pipe, a mixed-water chamber communicating with said two chambers and formed coaxially there with, a valve chest accommodated in said hot water supply chamber and said cold-water supply chamber and communicating with these two chambers through a hot-water inlet and a cold-water inlet, respectively, a main valve and a control valve slidably accommo dated in said valve chest, an elongate tubular body accommodated in said mixed-water chamber and connected with said valve chest, one end of said elongate tubular body which is disposed within said valve chest being 130 formed into a valve seat on which said control valve is adapted to rest, and a casing slidably fitting in said elongate tubular body and accommodating a temperature sensing element. 70

2. The fixture as set forth in claim 1, wherein a spring engages at opposite ends thereof against said main valve and sard control valve so as to bias said control valve against said valve seat.

3. The fixture as set forth in claim 1 or claim 2,wherein said control valve is provided with an annular sea[ on the side facing said main valve and another annular sea[ on the side facing said valve seat, the diameters of the annular axes of said seals being equal to the external diameter of said control valve.

4. The fixture as set forth in any one of Claims 1-3,wherein said casing is provided with a plurality of projections on the side facing said control valve so as to allow a plurality of recesses to alternate with these projections.

5. The fixture as set forth in any one of claims 1-4,wherein the space left between the internal surface of said casing and the external surface of said temperature sensing element is narrow.

6. The fixture as set forth in claim 3, wherein one end of said temperature sensing element projects from said casing so that when said another annular seal abuts on said valve seat, said one end of said temperature sensing element will slightly come into said control valve.

7. The fixture as set forth in any one of claims 1-6, further comprising a push rod, one end of said push rod being connected with said casing on the side reverse to the side facing said control valve, a plug threaded into said elongate tubular body and provided with a bore in which a means for holding the other end of said push rod is axially slidable, a spindle coupled with said plug at one end and - projecting externally at the other end, and a knob provided on the external end of said spindle.

8. A fixture for thermostatically mixing hot and cold water from hot and cold-water pipes, comprising a hot-water supply chamber for receiving hot water from the hot-water pipe, a cold-water supply chamber for receiving cold water from the cold-water pipe, a mixed-water chamber communicable with the hot and coldwater supply chambers, a control valve sli- dably accommodated in a valve guide and movable in response to a temperature sensing element to control the temperature of water supplied to the mixed-water chamber, the control valve having at each of two opposite ends an annular seal the mean diameter of which is equal to the inside diameter of the valve guide.

9. A fixture for thermostatically mixing hot and cold water from hot and cold-water pipes, comprising a hot-water supply chamber for GB2139324A 5 receiving hot water from the hot-water pipe, a cold-water supply chamber for receiving cold water from the cold-water pipe, a mixed water chamber commuicable with the hot and cold5 water supply chambers, a control valve slidably accommodated in a valve guide and --mova, ble in response to a temperature sensing element to control the temperature of water supplied to the mixed-water chamber, the temperature sensing element being mounted in a casing such that there is a space between the temperature sensing elenent and the casing through which water flows from the hot and cold water supply chambers to the mixed- water chamber, said space being so narrow as to be adapted to allow the temperature sensing element to quickly respond to a change in water temperature.

10. The fixture of claim 9, wherein the - space is an annular gap having a width of about 2mm.

11. A fixture for thermostatically mixing hot and cold water from hot and coid-water pipes, substantially as hereinbefore described with reference to, and as shown in, Figures 1-8 of the accompanying drawings.

Printed in the United Kingdom for Her Majesty's Stationery Office, Dd 8818935. 1984, 4235. Published at The Patent Office. 25 Southampton Buildings. London, WC2A l AY, from which copies may be obtained.

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