Regulator means for automatically shutting the gas pipeline passage off during pressure reducing failure
This is a continuation of application Ser. No. 008,764, filed 1-30-87, and now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     Currently, liquified propane gas fuel is widely utilized in ordinary households. The apparatus using liquefied propane gas includes a high pressure reducing regulator, and a low pressure pipeline connected with, for example, a gas oven, in which, the pressure reducing regulator has two functions: to transform the approximately 6 kg/cm 2  (60000 mmHg) high pressure gas in the steel cylinder to approximately 400 mmHg. low pressure gas and to release the high pressure gas if the pressure reduction function fails. A cause of pressure reducing failure is often simply because a user forgets to shut off the main supply valve or because foreign matter is deposited at a contact place between the outer end of a gas inlet port in the pressure reducing regulator means and a rubber pad attached to the head of a lever type boltshaft for reducing pressure. Such foreign matter prevents the rubber pad from normally adjusting the gas flow rate out of the gas inlet resulting that the pressure of the high pressure gas cannot be reduced to a predetermined level but results in a gradual pressure increase in the pressure reducing chamber. If no proper measure is taken to remove the defect, and the gas supply is still on, the low pressure pipeline will be damaged and may cause a disaster from leaking gas. To avoid such a danger, a conventional pressure reducing regulator is provided with an automatic pressure relief design to respond to a pressure reducing failure to automatically and immediately discharge the high pressure gas through a relief valve, whenever the pressure reduction fails and the pressure in the pressure reducing chamber is higher than the preset pressure. Although such a conventional design can prevent the high pressure gas from damaging the low pressure pipeline, it still has the following disadvantages. It is impossible to sense the pressure reducing failure and it is easy for disasters to occur, if and when the gas supply continuously flows without any warning. Although a relief valve is attached to a conventional pressure reducing regulator to discharge the high pressure gas from within, the discharged gas would fill up the space in the house, since for convenience the user often stores the gas steel cylinder in the house. This conventional method is still highly risky and poses a threat to harm the humans as well as damaging property. When the pressure reducing failure takes place during use, the high pressure gas may damage the low pressure pipeline and then leak gas in a large amount to cause a grave disaster. 
     Other conventional devices provide that a gas regulator means and an automatic flow shut-off device are used together to achieve the object of safety. For instance, the following U.S. Pat. Nos. are known: Satch 4,265,270; Joseph at al., 3,623,506; Kruzan et al., 3,228,417; Irwzn et al. 3,542,052; Galley et al., 3,180,356; Perry, 4,223,692; and Belese, 1,339,383. However, up to the present, the conventional devices have their own defects in that their structures are so complicated that a DC motor sensor or detector, or electromagnetic valve are used for control which often increases cost and also increases the damage rate of the whole assembly as shown, for instance in the U.S. Pat. Nos: 4,265,270, 3,180,350 and 4,233,692. Also in the prior art, a tool may be used for resetting the regulator, and this is comparatively more inconvenient, as disclosed for example in the U.S. pat. Nos. 3,623,506; 3,424,194, and 3,228,417. In the prior art, when abnormal overpressure conditions take place, the gas is discharged into the atmosphere. However, this discharge poses dangers of explosion, as for instance with the device disclosed in U.S. Pat. No. 3,542,052. Furthermore, none of the devices mentioned above are applied to situations where timers must be used to avoid fires due to a user&#39;s carelessness to shuff off the gas valve. 
     In order to overcome the defects of conventional regulator means, the applicant has thoroughly studied them and finally created this invention, a regulator means for automatically shutting off gas pipeline passage during a pressure reducing failure. The invention has three functions: to automatically shut off the flow of gas in the pipeline during gas overflow; to automatically shut off the flow of gas in the pipeline at a preset time; and to automatically signal the occurrence of a pressure reducing failure. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of this invention is to provide a regulator means for automatically shutting off the flow of gas in a pipeline during pressure reducing failure. 
     Another object of the invention is to rapidly sense pressure reducing failure when an automatically timed shut-off device is operated. 
     Another object of the invention is to provide a regulator means for automatically shutting off gas flow in a pipeline during pressure reducing failure where a piston valve is used to cut off the gas passage in the flow direction. 
     A further object of the invention is to provide a regulator means for automatically shutting gas pipeline passage off during pressure reducing failure which can automatically shut off the gas flow passage, in response to a gas overflow. 
     The regulator means of the invention for automatically shutting the flow of gas in a pipeline during pressure reducing failure includes: body member; a timing device; pressure reducing valve assembly; piston valve assembly; a transmission device assembly; and an automatic overflow control device. The body member basically includes a timing device chamber, a pressure reducing valve chamber, and a thin wall between said timing device chamber and said reducing valve chamber. The automatic overflow control device is positioned at the gas inlet pipeline. The timing device is received within the timing device chamber and, the pressing plate in the timing device actuates the piston valve installed in the reducing valve chamber via the transmission plate. When the regulator means is activated, after the gas pressure is reduced by the pressure reducing valve, then the pressure-reduced gas flows to the gas outlet pipeline through the piston valve. 
     The present invention will be best understood when the description of the preferred embodiments is read in connection with the accompanying drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIGS. 1-1, 1-2, and 1-3 together are views of the body member of the regulator means of the invention. More specifically, FIG. 1-1 is a top view of the body member. FIG. 1-2 is a sectional view along the central line of FIG. 1-1 and the enclosed area N in the FIG. 1-2 is a sectional view of an automatic overflow control device. FIG. 1-1 is a bottom view of the body member. 
     FIG. 2 is a perspective view of the lever type bolt shaft in the pressure reducing valve of the regulator means of the invention. 
     FIGS. 3-1, 3-2, and 3-3 are respectively top, side, and bottom views of the piston valve in regulator means of the invention. 
     FIGS. 4-1 and 4-2 are respectively side and top views of the centering guide plate for the piston valve of regulator means of the invention. 
     FIGS. 5-1 and 5-2 are respectively top and side views of the leakage-proof diaphragm between the piston valve and the transmission assembly in the regulator means of the invention. 
     FIG. 6-1 is a partially exploded perspective view of the transmission assembly in the regulator means of the invention. 
     FIGS. 6-2 and 6-3 respectively are top and side views of the transmission plate of the transmission assembly shown in FIG. 6-1. 
     FIGS. 7-1 and 7-2 respectively are top and side views of a cover plate for the timing device in the regulator means of the invention. 
     FIGS. 8-1 and 8-2 are respectively a top and side view of a timer adjustment plate for the regulator means of the invention. 
     FIG. 9 is a perspective view of the timing device, with its pressing plate and its leaf spring. 
     FIG. 10 is an exploded view of the regulator means of the invention for automatically shutting off the flow of gas in a pipeline during pressure reducing failure. 
     FIG. 11 is a cross-sectional view of a complete embodiment of a regulator means of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1-1, 1-2, 1-3 and 11, the body member 1 is of cylindrical shape. The outer ends of its two sides are gas inlet port 1A and outlet port 1B respectively. An inlet nozzle 1A 1  is provided close to the inner end of said inlet port 1A in said body member. A thin wall 1K is formed integrally with said body member 1 and transversely located in said body member and divides the hollow space in said body member into a pressure reducing valve chamber 1E and a timing device chamber 1H. A telescopic through hold 1E 1  is biased off the center of said thin wall surface and passes through said thin wall 1K. Three gas outlet ports 1E 2  are provided around the outer periphery of said telescopic through hole 1E 1  and also passing through said thin wall. Three fine partition bars 1E 3  are provided to separate each of said three gas outlet ports 1E 2  respectively. An annular flange 1E 6  which is a little higher than the wall surface 1K 1  is provided at the outer periphery of said gas outlet ports 1E 2  in the wall surface 1K 1  of said thin wall 1K facing said pressure reducing valve chamber 1E. The flange 1E 6  close to the outer periphery of said gas ports 1E 2  is provided with two opposite thin arcuate plates 1E 4 . Said two opposite thin arcuate plates 1E 4  are integrally formed with said wall surface 1K 1  and are used to confine and set a space for piston valve 9. See FIG. 11. 
     Two opposite round support posts 1E 5  with a suitable height are arranged at the place immediately adjacent to the outer sides of said two opposite thin arcuate plates 1E 4 . The end faces of said two opposite support round posts 1E 5  are provided with threaded hole 1E 51  for mating and securing the centering guide plate 9D (see FIGS. 4 and 11) of piston valve assembly by screws 
     The opposite protruding posts 1D are installed symmetrically on the two front sides of inlet nozzle 1A 1  and are higher than the inlet nozzle 1A 1  and also have an elongated recess 1D 1  and a threaded hole 1D 2  respectively to secure the pressure reducing component 2 described below. 
     On the wall surface 1K 2  of said thin wall 1K that faces the timing device chamber 1H and close to said gas ports, an upright annular flange 1H 4 , which is slightly higher than said wall surface 1K 2 , is provided. A semicircular groove 1H 2  is in said wall surface 1K 2  that is opposite to a semi-circular convex surface 1E 7 . A gas outlet port 1F is located at the semi-circular groove 1H 2  and also on the groove surface near the gas outlet 1B. H 2  communicates with the outlet 1F, and also communicates with the pressure reducing valve chamber 1E when the piston valve 9 is open, thereby permitting the gas flow to the outlet 1B from the inlet 1A. 
     A fine elongated moon-shaped small groove 1H 3  is provided at the corresponding place on the opposite side of the body member relative to said semi-circular groove 1H 2  and provides the gas inlet nozzle 1A 1  to serve as a gas inlet channel. 
     On the outer periphery of said upright annular flange 1H 4 , there is also an annular groove 1H 5  to mesh with leakage-proof diaphragm 8 (see FIG. 5). A semi-circular support rack 1H 6  is provided in said timing device chamber 1H and is also integrally formed with said body member 1, and the height of said rack 1H6 is a little shorter than that of the top plane of said timing device chamber 1H. The top end face of said rack 1H 6  is provided with threaded holes to match the opposite round holes in a timing device cover plate (see FIG. 7), respectively, for fastening the timing device with screws. 
     Referring to FIGS. 2, 10 and 11, the pressure reducing valve assembly is composed of a pressure reducing assembly 2, a leakage-proof diaphragm 10, a round metal plate 11, a spring 12, a cover 13, an adjustment ring 14 and a bottom cover 15. The lever-type bolt 2 in the pressure reducing assembly shown in FIG. 2 is made of bended light metal with a square hollow head 2A 1 . A round thin pad 2A 3  made of rubber contacts the gas inlet nozzle 1A 1 . Rear end 2A 2  is formed in a small arc cross section to secure the leakage-proof diaphragm 10 by passing through slot 10A in diaphragm 10. On each of the two sides said square hollow head 2A 1  is oppositely provided a through hole 2A 4  respectively, to receive a pivot shaft 2A 5  therein. The head of the screw mating the hole 1D 2  (see FIG. 1-3) is fixed and installed in the elongated recess 1D 1  to secure the pressure reducing assembly by the pivot shaft 2A. The distance from the pivot shaft 2A 5  to the tail end 2A.sub. 2 is longer than that from the pivot shaft 2A 5  to the head 2A 1 . 
     Referring to FIGS. 3-1, 3-2, and 3-3, a piston 9A 1  of piston valve assembly 9 is illustrated. Said piston valve assembly consists of a piston 9A 1 , a leakage-proof rubber pad 9B, a spiral spring 9C (see FIGS. 10 and 11) and a centering guide plate 9D (see FIGS. 4 and 11), in which said piston 9A 1  is provided with an upper round protruding post 9A 2 , a round plate 9A 3  and an annular projection 9A 4  formed below said round plate 9A 3 . Said leakage-proof rubber pad 9B is bonded on the top plane of the round plate 9A 3 . The upper round protruding post 9A 1  above said piston 9A is inserted into the hole 1E 1  from the pressure reducing valve chamber 1E side. After the piston valve assembly is located in the hole 1E 1 , said round leakage-proof rubber pad 9B presses directly against the annular flange 1E 6  at the outer periphery of said gas outlet ports 1E 2 . The large diameter end of the spiral spring 9C engages said annular projection 9A 4 . The end face line of the end of said lower round protruding post 9A 2  on said round plate 9A 3  is approximately flush with end faces of said two round support posts 1E 5  in the body member 1. 
     Referring to FIGS. 4-1 and 4-2, a centering guide plate 9D is shown. Said centering guide plate 9D basically is a strip shaped metal sheet; its width is a little larger than the outside diameter of said two round supports posts 1E 5  and its length is a little longer than the distance between said two round support posts 1E 5 . Each of its two ends along the direction of the longitudinal axis of the centering guide plate 9D is provided with an arc respectively, and near each of the two arcs is provided a round hole 9D 1 , respectively, to mate the threaded holes 1E 5 , in the top face of said two round support posts 1E 5 . A hole 9D 3  is located at the center of said centering guide plate 9D, and 9D 3  in flange 9D 4  is slightly higher than the end face 9D 2  and is provided at said center hole 9D 3  in the end face 9D 2 . While said round protruding post 9A 1  is inserted into the through hole 1E 1 , the larger diameter end of said spiral spring 9C is engaged with said annular projection 9A 4  and the smaller diameter of said spiral spring 9C is engaged with the flange 9D 4  of said centering guide plate 9D, so that the spring 9C can be kept in position under a contracted or released condition without any radial shifts and inclinations. 
     In operation, when the two round holes 9D 1  in two ends of the centering guide plate 9D and both threaded holes at the top planes of said two round support posts 1E 5  are mated together and fastened by screws resulting in the proper positioning of the spring 9C, the restoring force produced by the spring 9C under the pressure of the centering guide plate 9D can make the leakage-proof rubber pad 9B tightly block the gas outlet ports 1E 2 . 
     An important feature of the present invention is that the piston valve assembly 9 is arranged in the pressure reducing chamber 1E with a design to shut off gas flow through the gas outlet ports 1E 2  in the flow direction. Therefore, even if the pressure in the pressure reducing valve chamber 1E increases sharply during a pressure reducing failure, the high pressure gas in the pressure reducing valve chamber will urge the rubber pad 9B tightly against gas outlet ports 1E 2 , and the unacceptably high pressure gas will not leak out. This feature of the present invention eliminates the disadvantage of conventional gas regulators which do not shut off the gas flow during pressure reducing failure. 
     Referring to FIGS. 5-1 and 5-2, leakage-proof diaphragm 8 is shown in said drawing. One of end faces 8A in said leakageproof diaphragm 8 is provided with two annular gooves 8A 1  and 8A 2  respectively. An annular surface 8A 3  is enclosed by said annular groove 8A 2 , and a central round concave surface 8A 4  is enclosed by said annular surface 8A 3 . Near the circumference of the outer periphery of the diaphragm 8 and around another end face 8B of said leakage-proof diaphragm 8, an annular groove 8B 1  is provided, and except for the part of the end face that is occupied by the annular groove 8B 1 , the remainder of the end face is a flat plane. Said leakage-proof diaphragm 8 is meshed on the wall surface 1K 2  of thin wall 1K of the body member 1. When the diaphragm is meshed on the wall surface 1K 2 , the projection 8A 5  between annular grooves 8A 1  and 8A 2  in the end face 8A is inserted in to the annular groove 1H 5 . Said leakage-proof diaphragm 8 is provided to avoid gas leakage and also to separate the piston valve assembly 9 from the transmission assembly 3 shown in FIGS. 6-1, 6-2, 6-3, and 11 and described below and to separate the piston valve assembly 9 from the transmission timing device 9 (see FIG. 9). 
     Referring to FIGS. 6-1, 6-2, and 6-3, the transmission assembly 3 of the timing device 4 is shown. Said transmission assembly 3 consists of a transmission plate base 3A and a transmission plate 3B. At each of the two intersections of the circumference and the longitudinal axis of said transmission plate base 3A is provided with protruding lugs 3A 31 , 3A 32 , respectively and end edges of said two protruding lugs 3A 31 , 3A 32  are of a concave arc shape. A rectangular hole 3A 1  is located in the longitudinal center of the transmission plate base 3A and also in the position approximately 30° in the counterclockwise direction. The central line of the longer side of said rectangular hole 3A 1  and the longitudinal central of said transmission plate base 3A intersect at the place near the protruding lug 3A 32 . On the lateral sides of the end portion of said rectangular hole 3A 1  and near the protruding lug 3A 31 , two opposite small square protruding plates 3A 2  A and 3A 2  B are provided. Pivotal holes 3A 2  A 1  and 3A.sub. 2 B 1  are provided in said two small protruding plates 3A 2  A and 3A 2  B respectively. Near the protruding plug 3A 32 , the width of said shorter part 3A 12  of said rectangular hole 3A 1  is slightly smaller than that of its longer part 3A 11 . Three rectangular support rack plates 3A 4  which have their own respective suitable lengths and are perpendicular to said transmission plate base 3A are provided and equally spaced on the periphery of said transmission plate base 3A. Top ends of said three support rack plates 3A 4  have arc cutouts 3A 4  1 so as to support fastening bolts 21 on the timing device to provide a proper space between said timing device 4 and said transmission plate base 3A. Transmission plate 3B has an upwardly tapered tail 3B 1  and a flush straight head 3B 2 . The end edge of said head 3B 2  is provided with two opposite protruding lugs 3B 4  A, 3B 4  B which are perpendicular to the post plate surface 3B 21  of said head 3B 2 . Said protruding lugs 3B 4  A, 3B 4  B are also provided with pivot through holes 3B 4  A 1  and 3B 4  B 1  so as to align with the pivot holes 3A 2  A 1  and 3A 2  B 1  and then to receive a pivot shaft 3B 5  to pivotally connect said transmission plate 3B and said transmission plate 3A into a single unit. Said transmission plate 3B is made of a metal sheet approximately 1 mm in thickness; and its width is a little wider than that of said rectangular hole 3A 1 . The length of said head 3B 2  is almost same as that of longer part 3A 11  of rectangular hole 3A l . A small rectangular plate 3B 3  which separates from said head 3B 2  is formed at the intersection of said head 3B 2  and said upwardly tapered tail 3B 1  and extends toward the central part of said head 3B 2 . Said small rectangular plate 3B 3  declines downward, but its rear end slightly inclines upward. Its head end depends from said head 3B 2 . The disposition of said transmission assembly 3 is such that the protruding lug 3A 31  and transmission plate base 3A are made (1) to directly and respectively press against the two opposite ones of said four semi-circular support racks 1H 6  on the inner walls of said timing device chamber 1H in the body member to make said transmission plate base easily positioned and also to remove any worry about displacement of said transmission plate base during the assembly process; and (2) to make the small rectangular plate 3B 3  on said transmission plate 3B precisely press against the round protruding post 9A of said piston valve 9 with said leakage-proof diaphragm 8 therebetween. 
     A fixing cover plate 5 of the timing device is shown in FIGS. 7-1 and 7-2. Said cover plate 5 basically is a round plate. A large and elongated cutout 5C, slightly in an arc form, is located on said cover plate 5. The three small holes 5A in said cover plate 5 are to receive the three fixing screws on timing device 4. The four larger round holes 5B closer to the periphery of the circumference are to mesh the four threaded holes H7 in the top of the four semi-circular cross section support racks 1H 6  on the inner wall of said timing device chamber in the body member 1 and then said four fixing screws are used to secure the cover plate 5 to the body member 1. 
     Furthermore, fastening bolts 21 on the timing device as shown in FIG. 11 pass through holes 5A in cover plate 5 and rest upon support rack plates 3A 4  for positioning and fixing the timing device with respect to the transmission plate base 3A. In this way, the transmission plate base 3A is directly fixed. Since the periphery of said leakage-proof diaphragm 8 is secured, gas is unable to leak into the timing device chamber 1H. During and after assembly, the assembler can observe through said cutout 5C to check if the assembly is accurate or not and if the transmission plate 3B can precisely actuate the piston valve or not. 
     Furthermore, as shown in FIGS. 9, 10, and 11, a pressing plate 4A in the timing device 4 is provided with a rectangular leaf spring 4B, and the end of said leaf spring 4B directly presses against one of the fixing bolts 4C on said timing device 4. When the timer is set to provide gas flow, a pressing action of the leaf spring 4B forces the tail end of the pressing plate 4A to press against the upwardly tapered tail 3B 1  (see FIG. 11) to keep the upwardly tapered small rectangular plate 3B 3  of said transmission plate 3B pressing downward directly against the top of the piston 9A of the piston valve assembly 9 so as to keep the piston valve assembly 9 in the open state. The open state of the piston valve assembly 9, in turn, permits the pressure reducing valve chamber 1E to communicate with the gas outlet port 1F (see FIG. 1-2) via the gas outlet ports 1E 2 , thereby making the gas flow to a gas-using apparatus via the gas outlet ports 1E 2 , gas outlet port 1F, and the gas outlet 1B from the gas pressure reducing valve chamber. 
     In contrast, when the timer is turned to zero, the tail end of the pressing plate no longer presses downward directly against said transmission plate 3B, and the piston valve assembly 9 is in the closed state. Said small rectangular plate 3B 3  is formed of an approximately 1mm thick metal sheet, and its end can bear about 0.5 kg/cm 2  pressure. Therefore, when the pressure born by said small rectangular plate 3B 3  is above 0.5 kg/cm 2 , said small rectangular plate 3B 3  will bend upward and become flat, so that it is impossible to actuate the piston valve 9. Therefore, when a pressure reducing failure occurs to render the pressure in pressure reducing valve chamber to increase about 0.5 kg/cm 2  (about 10 times of the generally normal pressure of 400 mm Hg) and flatten the small rectangular plate 3B, said piston valve assembly 9 is unable to be opened to supply gas through low pressure pipeline. By this automatic shut off of gas flow in the event of a pressure reducing failure, the user can be signaled that a pressure reducing failure has occurred. 
     Referring to FIGS. 8-1, 8-2, 10, and 11, a time scale plate 6 is meshed on the top plane of the timing device chamber of the body member 1. Said scale plate 6 is engraved with marks like 0-60 minutes and fully open position to allow the user&#39;s setting the length of time they desire to use the gas. The spindle 22 of said timing device 4 protrudes through the center hole of said time scale plate 6, and the top of its spindle is attached with the manually adjusted rotary disc 7 of the gas valve. 
     During the assembly of the reducing valve arrangement, the leakage-proof diaphragm 10 is first attached to the tail stock 2Ag of the lever type bolt shaft. Then the round metal plate 11 is mounted on the bottom of the leakage-proof diaphragm 10, and the spring 12 is positioned to directly press against the bottom of round metal plate 11. Then the adjustment screw 14 and bottom cover 15 are fixed on the pressure reducing valve cover 13. Finally the pressure reducing valve cover 13 is fastened to the end edge of pressure reducing valve chamber by screws. No pressure relief hole is provided in the center part of the leakage-proof diaphragm (this is different from that of conventional leakage-proof diaphragms), so that no gas will be leaked out even during the pressure reducing failure. 
     In order to complete the gas regulator apparatus of the invention, a set of automatic overflow control devices is arranged at the gas inlet 1A 1  of this device. More specifically, as shown in portion N in FIG. 1-2 and in FIG. 11, an automatic overflow control device 16 which is mounted near the gas inlet pipeline passage. The automatic overflow control device includes an automatic shut-off assembly which is located between the gas inlet 1A and the body member 1 to automatically shut off the gas flow in the pipeline passageways during (1) pressure reducing failure and (2) serious gas leakage situations. A release button assembly is located near the automatic shut off 16A to enable a user to manually knock down a stainless steel round bead 16A 2 , which stops gas flow, in order to re-open smooth gas flow in pipeline gas flow. Said automatic shut-off assembly 16A further includes: (1) an oil seal ring 16A 1  provided at the gas inlet 1A in the body member 1 and located between a pipeline passage 1A 2  with a diameter larger than that of the round bead 16A.sub. 2 ; (2) a smaller pipeline passage 1A 3  ; (3) a stainless steel bead 16A 2  located in front of the oil seal ring 16A 1  to block the opening of said oil seal ring 16A 1  ; and (4) a positioning spring 16A 3  or an eccentric round steel sheet (not shown in the drawing) located in front of said stainless steel bead 16A 2  to prevent said stainless steel bead 16A 2  from rolling too far away from said oil seal ring 16A 1 . Therefore said round bead 16A 2  is able to stay at a suitable position in the pipeline passage 1A 2  without rolling too far away from its open position. Release button assembly 16B further includes: (1) a base 16B 3  ; (2) a connecting rod spindle 16B 5  ; (3) an oil seal ring 16B 4  ; (4) a spring 16B 2  ; and (5) a push cap 16B 1 . The base 16B 3  has threads and is mounted at the top of the pipeline passage 1A2. The connecting rod spindle 16B 5  has a lower part with a bottom having a larger outer diameter and an upper part with threads for engaging with the push cap 16B 1 . The seal ring 16B 4  is located above the larger bottom of the spindle 16B 5  and is also tightly frictionally fitted with the spindle 16B 4  to avoid gas leakage. The spring 16B 2  is provided between the push cap 16B 1  and base 16 3  to restore the push cap 16 1  and the connecting rod spindle 16B 5  that engages the push cap 16B 1  to their original positions together, when the pressure applied to the top of the push cap 16B 1  is released. 
     In operation, the high pressure gas flows into the pressure reducing chamber 1E from the pipeline inlet 1A via the inlet nozzle 1A 1 . The round thin pad 2A 3  on the pressure reducing component 2 comes into contact with and out of contact with the gas inlet nozzle 1A 1  to control the flow-in gas volume, which inturn, adjusts the gas pressure in the pressure reducing chamber 1E. The pressure reducing component 2 is pivotally fixed, with its pivot 2A5 on the rectangular recess 1D 1 , and the distance between the pivot 2A 5  and the tail 2A 2  is longer than the distance between the pivot 2A 5  and the head 2A 1 . When the pressure of gas entering the pressure reducing chamber 1E becomes high, the high pressure is applied on the leakage-proof diaphragm 10 and is strong enough to overcome the spring 12. The net resultant force of the force applied by the round metal plate 11 on the leakage-proof diaphragm 10 and the force applied on the round thin pad 2A 3  causes the round thin pad 2A 3  of the pressure reducing component 12 to move toward the gas inlet nozzle 1A 1  to prevent further entry of high pressure gas, and the pressure in the pressure reducing chamber changes. This, in turn, causes the volume of gas flowing into the pressure reducing chamber 1E to be reduced which also causes the gas pressure to lower. Conversely, when the pressure of the gas flowing into the pressure reducing chamber 1E is low or non-existent, the low gas pressure therein will cause the gas pressure that is applied to the leakage-proof diaphragm 10 to be reduced, which in turn permits the force that the spring 12 applies to the leakage-proof diaphragm 10 to overcome the opposing force that the gas applied to the leakage-proof diaphragm 10. Thereby, the round thin pad 2A 3  on the pressure reducing component 2 moves in a direction away from the gas inlet nozzle 1A 1  to cause the volume of gas flowing into the pressure reducing chamber 1D to increase. This inturn causes the gas pressure in the pressure reducing chamber to also increase. The above described method of operation causes the gas in the pressure reducing chamber to maintain a stable selectable pressure level. A user can use the adjustment element 14 to adjust the force that the spring 12 applies on the leakage-proof diaphragm 10 properly to adjust the outlet gas pressure. 
     As shown in FIGS. 9 and 11, on the lower side of the timing device 4 in a round piece having a cutout which meshes a protrusion of the pressing plate 4A. When the cutout engages the protrusion, the timer is zeroed to shut off the piston valve assembly 9. When the timing device 4 is turned clockwise, for instance, to the 30-minute mark, said cutout gets off the protrusion to make the pressing plate 4A outwardly press the tail 3B 1  to the transmission plate 3B. The transmission plate 3B moves outward and causes the small rectangular plate 3B 3  to press downward against the piston 9A of the piston valve assembly 9, thereby moving the piston valve assembly 9 to an open state. Upon expiration of the preset 30-minute period, the cutout and the protrusion engage together again to shut off the piston valve assembly 9. 
     Just like conventional times in the prior art, the timing device 4 enables the time that the cutout and protrusion restore their engagement to be controlled by the timing device 4. The time scale plate 6 indicates the time required to achieve the purpose of time control. However, when the timing device 4 is turned counterclockwise (not clockwise for setting a timed gas flow), this will make the piston valve fully open and free from the time control. In such a case, the gas pipeline passage is fully open without any time limit, and since this belongs to the conventional skill and art, no detailed elaboration on such a position is needed here. 
     When the pressure in the pressure reducing chamber 1E increases to 0.5 kg/cm 2 , which is the maximum level that the small rectangular plate 3B 3  can withstand during a pressure reducing failure of the related assembly, the small rectangular plate 3B 3  will be pressed flat by the up-bending piston 9A 1 . When bent thusly, the plate 3B 3  can no longer actuate the piston valve 9. 
     Summarizing the above description, this invention not only shuts off the gas flow in the pipeline passage at the pressure reducing failure but also signals the pressure reducing failure by means of its transmission plate. Furthermore, the invention automatically shut off gas flow in the pipeline passage during gas overflows to avoid serious disasters.