Title of Invention

A GAS METER

Abstract

The invention relates to a gas meter comprising a plurality of deformable diaphragm (28) measurement chambers (26), a distributor element (64) mounted to rotate about a "rotation" axis on distribution surface (42f) in which there are provided a plurality of orifices (44, 46, 48, 50) each of which is connected to a respective measurement chamber, said distributor element enabling gas to enter and to leave the measurement chambers in alternation during its rotary movement, and means for guiding said distributor element in rotation comprisIng firstly a guide piece (94) having at least a portion of generally elongate shape along the axis of rotation with two cylindrical regions (96, 98b) spaced a from each other, and secondly two bearings (104a, b) in which said cylindrical regions are mounted to rotate freely, the meter being characterized in that the guide piece (94) is a thermoplastic material and the cylindrical regions (96, 98b) are of different diameters.

Full Text

The invention relates to a gas meter. Such gas meters comprising rotary guide means for the distributor element are known, and Figure 1 shows an embodiment thereof. In Figure 1, a structure given overall reference 1 comprises a frame 3 in which two bearing-forming housings 5 and 7 are formed (the gas meter and the distributor element are not shown). The guide means comprise a guide piece 9 in the form of a crank having a portion 11 that is constituted by a brass cylinder having the same diameter over its entire height and engaged in the two openings 5 and 7 of the frame 3. The cylinder 11, and thus the guide piece 9, are guided in rotation at the bearings 5 and 7 by cylindrical regions of the cylinder 11 that are spaced-apart from each other. A handle 13 of sheet metal is disposed perpendicularly to the axis of the cylinder 11 and is crimped on the end 11a thereof This handle includes a finger 15 extending parallel to the axis of the cylinder 11 offset therefrom. The finger 15 is designed to co-operate with the distributor element (situated below) in order to guide its rotary movement. The top portion lib of the cylinder 11 has a plastics washer 17 provided to hold the guide piece 9 axially and prevent it from exerting a downward thrust force on the distributor element. That guide piece suffers from the drawback of being difficult to assemble and it would consequently be advantageous to find a solution that is simpler. The present invention seeks to remedy that problem by proposing a gas meter comprising a plurality of deformable diaphragm measurement chambers, a distributor element mounted to rotate about a "rotation" axis on a distribution surface in which there are provided a plurality of orifices each of which is connected to a respective measurement chamber, said distributor element enabling gas to enter and to leave the measurement chambers in alternation during its rotary movement, and means for guiding said distributor element in rotation comprising firstly a guide piece having at least a portion of generally elongate shape along the axis of rotation with two cylindrical regions spaced apart from each other, and secondly two bearings in which said cylindrical regions are mounted to rotate freely, the meter being characterized in that the guide piece is made of a thermoplastic material and in that the cylindrical regions are of different diameters. The fact of using a thermoplastic material makes it possible to obtain the entire guide piece in a single unmolding operation so there is no longer any need to assemble said guide piece using a complicated method. The Applicant has also found that it is necessary to have two cylindrical regions of different diameters for the guide piece made of thermoplastic material so that head loss problems do not arise due to the mechanical wear of the portions that come into contact. If, as in the prior art, the guide piece were to conserve the same diameter over its entire height, e.g. 15 mm, then, because of the unmolding operation and thus the need to have draft on the pieces that are to be unmolded, it would be technically impossible for said guide piece and the other portion of the guide means including the bearings to have identical amounts of draft, given the height involved. As a result there would necessarily be unequal mechanical clearance over the full height of the guide piece, giving rise to premature mechanical wear and to inevitable problems of head loss in the meter. With cylindrical regions of different diameters, and for a given height of the guide piece, the draft of said cylindrical regions is fully under control and the same draft can be obtained for corresponding bearings which guarantees identical mechanical clearance over the full height of the guide piece. In addition, thermoplastic material presents the advantage of being low in cost, so the increase in the diameter of the cylindrical regions of the guide piece has little repercussion on the cost of manufacturing such a piece. By performing the operation of unmolding the guide piece in a direction that is parallel to the longitudinal direction of said guide piece, it can be guaranteed that the two cylindrical regions remain accurately on the same axis. This means that clearance in the bearings can be reduced, thus leading to a reduction in wear and in head losses in the meter. Accordingly, the present invention provides a gas meter comprising a plurality of deformable diaphragm measurement chambers, a distributor element mounted to rotate about a "rotation" axis on distribution surface in which there are provided a plurality of orifices each of which is connected to a respective measurement chamber, said distributor element enabling gas to enter and to leave the measurement chambers in alternation during its rotary movement, and means for guiding said distributor element in rotation comprising firstly a guide piece having at least a portion of generally elongate shape along the axis of rotation with two cylindrical regions spaced a from each other, and secondly two bearings in which said cylindrical regions are mounted to rotate freely, the meter being characterized in that the guide piece is a thermoplastic material and the cylindrical regions are of different diameters. According to a characteristic, the larger diameter cylindrical region is closer to the distributor element. In a variant, the guide piece may have a frustoconical region interconnecting the two different-diameter cylindrical regions. More particularly, the guide piece is in the form of a crank having one end constituted by the cylindrical regions engaged in the bearings, and whose other end is constituted by finger parallel to the axis of rotation and offset therefrom, which finger co-operates with a cavity formed in the distributor element. According to a characteristic of the invention, the gas meter includes a U-shaped carrier structure whose inside faces towards the distributor element so as to surround it, and supporting the guide piece, the elongate portion of said guide piece being engaged in a housing provided in the structure via one end of said housing which is disposed at the same end as the distributor element, the bearings being arranged inside said housing. Furthermore, the gas meter of the invention comprises an axial retaining member for the guide piece to prevent said guide piece from exerting a vertical downward force on the distributor element. For example, the axial retaining member for the guide piece is a peg engaged in an axial sheath provided inside the guide piece from its end opposite from the housing, said peg being fixed to said guide piece in removable manner and being provided on the outside of said sheath with a shoulder forming a head which bears against the carrier structure so as to retain said guide piece axially. The peg is fixed to the inside of the sheath by snap fastening, for example. More precisely, the peg has an annular groove on one of its diameters to co-operate with an annular bead formed on the inside surface of the sheath. In addition, the head of the peg bears against the carrier structure by means of an annular surface extending perpendicularly to the axis of rotation. The gas meter of the invention also comprises a display totalizer and the guide piece includes a gearwheel for transmitting the rotary movement of the distributor element to said totalizer via a gear train. For example, the gearwheel is disposed at the end of the elongate portion of the guide piece which is closest to the distributor element, and is perpendicular to said portion. The guide piece may comprise a turntable which carries the gearwheel on one of its faces. The turntable carries on its opposite face the finger which co-operates with the distributor element. More particularly, the U-shaped structure is constituted by a central portion parallel to the distribution surface and two side portions forming the branches of the U-shape, said central portion including a base of generally circular shape disposed in a plane PI extending parallel to the distribution surface and provided at its periphery with a collar disposed perpendicularly to said base in such a manner as to define a cavity situated facing the distributor element and designed to receive its gearwheel. On either side of the base, the central portion of the U-shaped structure includes two regions situated in a plane P2 parallel to the distribution surface and offset from the plane PI by a distance that is greater than the thickness of the gearwheel, one of said regions carrying a pivot capable of receiving another gearwheel of the gear train, and a recess being provided in said base and in said collar so that the gearwheels can co-operate with each other. The other region of the central portion carries a pivot capable of likewise receiving another gearwheel of the gear train, and another recess being formed in the base and the collar on the side opposite to the first recess so that the gearwheels can co-operate with each other. Other characteristics and advantages of the invention appear from the following description given purely by way of non-limiting example and made with reference to the accompanying drawings, in which: - Figure 1 shows guide means for a distributor element of a prior art diaphragm gas meter; - Figure 2 is a perspective view of a gas meter of the invention, showing passages 3 0 to 3 8 for admitting gas into the meter and for evacuating it therefrom; - Figure 3 is a perspective view of the gas meter of the invention showing a diaphragm 28 and a cover 24 fitted to the central block 22; - Figure 4 is a perspective view from above of the gas meter of the invention in the same position as that shown in Figure 2, but having the distribution cover 42, the plate 40, and the pins 66 and 68 added thereto; - Figures 5 and 6 show the distributor element 64 respectively in a perspective view and in a view from beneath; - Figure 7 is on a larger scale showing the top portion of the gas meter of the invention and in particular the distributor element 64, the carrier structure 80, and the transmission means 70, 72, 74, and 76; - Figure 8 is an exploded view showing the guide piece 84 and the carrier structure 80; and - Figure 9 shows the guide piece in section when mounted in the carrier structure 80. As shown in Figures 2 and 3 and given overall reference 20, the gas meter of the invention comprises firstly a central block referenced 22 and two side covers, only one of which 24, is visible in Figure 3. The central block 22 defines two chambers, only one of which 26 is shown in Figure 2. Each chamber is defined firstly by the central block 22 and secondly by a deformable diaphragm (diaphragm 28 in Figure 3). When the covers are fitted to the central block 22, they co¬operate with the respective deformable membranes to define two other measurement chambers. Thus, there are two measurement chambers situated on either side of each deformable diaphragm and the volumes of these chambers vary depending on the positions of the diaphragms. As shown in Figure 2, the central block 22 defines four passages 30, 32, 34, and 36 in its internal structure, each passage communicating with a respective one of the measurement chambers. For example, the passage 30 communicates with the measurement chamber 26 and the passage 34 communicates with a measurement chamber (not shown in Figure 2) which is symmetrical to the measurement chamber 26 about the central block 22. The central block 22 also defines a fifth passage referenced 3 8 which enables gas to be evacuated from said central block. In Figures 3 and 4, a sheet metal plate 4 0 has been placed over the passages 3 0 to 3 8 and a piece referred to as a "distribution cover", referenced 42, is placed on said plate 40. The cover 42 has four openings or ports 44, 46, 48, and 50 each in the form of a quarter sector of a circle, and they are separated from one another by radial sealing strips 42a, 42b, 42c, and 42d. In the central portion of the distribution cover 42, a circular ring 42e co-operates with the radial strips 42a-d to define four orifices 52, 54, 56, and 58. Each of these orifices communicates with the outlet passage 3 8 and the outlet passage is terminated by an opening 60 formed through the closure plate 40. In the center of the distribution cover 42, a pivot 62 is mounted on an axis perpendicular to the top surface 42f of the distribution cover 42, which surface is referred to as the "distribution" surface. The pivot is designed to receive a distributor element that is also referred to as a "distributor". The distributor 64 is mounted to rotate on the distribution surface 42f of the distribution cover 42 and it slides on said surface. The distributor is constituted by four circular sectors which are arranged in such a manner as to form an orifi ce 64a and a setback zone 64b (Figure 5) separated by two plane zones 64c and 64d. Each of these four zones occupies an angle of 90°. The distributor also has a hollow central zone 64e (Figure 6) which communicates with the hollow setback zone 64b. In the light of Figures 5 to 7, it will readily be understood that the orifice 64a serves to put each of the ports 44, 46, 48, and 50 successively into communication with the outside of the central block 22, that the setback zone 64b and the central zone 64e are to put the outlet passage 3 8 into communication with one of said ports while isolating the assembly from the outside of the central block, and that the plane zones 64c and 64d close the remaining ports. As is well known, rotation of the distributor serves to control the admission and the evacuation of gas into and from the various measurement chambers. Meters having four chambers and a rotary distributor are well known in themselves, e.g. from US patent No. 3 161 049. There is therefore no need to describe the operating details of such a meter, .i.e. the relationships between the position ■•6f the rotary distributor 64 and the positions of the membranes in the measurement chambers. Reference can be made to the above-cited document. Nevertheless, it is appropriate to mention that the gas meter has transmission means for dynamically connecting the distributor to the deformable membranes. As shown in Figures 3, 4, and 7, the transmission means comprise two pins 66 and 68 passing through the block 22 over a fraction of its height and communicating with the measurement chambers of the meter. In Figure 4, a portion of the pin 66 can be seen in the chamber 26. Each of these pins is connected to a deformable diaphragm, and under the effect of the displacement of said diaphragm it performs corresponding pivoting motion. As shown in Figure 7, the transmission means also comprise two sets of levers 70, 72, and 74, 76. These sets of levers connect each of the pins 66, 68 to another pin 78 (Figure 8) which is engaged in an opening 7 9 (Figure 5) formed in the distributor 64. Thus, the movement of the deformable diaphragms during admission and evacuation of gas into and out from the measurement chambers is communicated by the transmission means to the distributor 64 which performs corresponding rotary-motion. As shown in Figure 7, a structure 80 is mounted on the central block 22 immediately above the distributor element 64. This carrier structure 80 is generally U-shaped, with the inside of the U facing towards the distributor element so as to contain it. The U-shaped structure 80 is constituted by a central portion parallel to the distribution surface 42f and two side portions 80a and 8 0b forming the branches of the U-shape. The central portion of the structure has a base 80c of generally circular shape lying in a plane PI parallel to the distribution surface 42f and provided at its periphery with a collar 80d disposed perpendicularly to said base so as to define a cavity 81. The central portion of the structure has two plane regions 80e and 80f on either side of the base 80c and lying in a plane P2 parallel to the distribution surface but axially offset from the plane PI. One of the regions 80f carries a pivot 82 for receiving a gearwheel 84, as shown in Figure 7. A recess 86 is formed in the base 80c and in the collar 8 0d so as to enable the gearwheel 84 to engage in the cavity 81. The other region 80e of the central portion of the structure 80 carries a pivot 88, likewise designed to receive another gearwheel (not shown in the figures) when the gearwheel 84 is not present, and another recess 90 is formed in the base of the collar on its side opposite to the first recess, thus enabling said other gearwheel, if any, to penetrate into the cavity 81. The branches 80a, 80b of the carrier structure 80 are provided at their free ends remote from their ends connected to the central portion with fixing tabs 80g, 80h which are designed to co-operate with the top portion 92 of the central block 22. Rotary guide means for the distributor element 64 are provided and are shown in Figures 8 and 9. Figure 8 is an enlarged side view of the central portion of the carrier structure 80, with the guide means being shown in section on a plane including the axis of rotation of the distributor element 64 which coincides with the axis of the pivot 62. The remainder of the central portion is not shown in section. These guide means comprise a crank-shaped piece 94 (Figure 8). The guide piece 94 has a generally elongate portion which is constituted by two cylinders of different diameters, a first cylinder 96 of relatively small height, e.g. about 6 mm, and a second cylinder 98 of greater height than the first cylinder, e.g. about 14 mm. The guide piece also has a circular turntable 100 and a gearwheel 102 mounted on one of the faces of the turntable 100. The elongate portion of the guide piece 94 constituted by two cylinders 96 and 98 is mounted centrally relative to the gearwheel 102 so that the end of the elongate portion carrying the larger diameter cylinder 96 is connected to said gearwheel. As shown in Figure 9, the central portion of the guide piece is hollow. The turntable 100 also carries, on its opposite face, a finger 78 (described above) which is parallel to the axis of rotation of the distributor element 64 and which engages in the opening 79 of said element, as shown in Figure 5. To simplify manufacture, the guide piece 94 is made as a single piece. The central portion of the carrier structure 8 0 has a cylindrical piece 104 (Figures 7 to 9) mounted on the base 80c and in which a housing 106 is provided in alignment on the axis of rotation of the distributor element 64. As shown in Figure 9, the guide piece 94 is engaged by means of its elongate portion in the housing 106 provided for this purpose. Thus, when the piece 94 is engaged in the housing 106, the cylindrical region 96 co¬operates with a first bearing 104 and the gearwheel 102 is received in the cavity 81. The cylinder 98 has two cylindrical regions 98a and 98b, and the second cylindrical region 98b co-operates with a second bearing 104b of the piece 104. Thus, the spaced-apart cylindrical regions 96 and 98b of different diameters serve to provide guidance inside the bearings 104a and 104b. The piece 94 is made of a thermoplastic material. Thus, this piece is easy to make by molding and unmolding, and its cost of manufacture is cheaper than the cost of manufacturing the above-described prior art piece, which is built of different materials. In addition, this guide piece can easily be assembled with other pieces, e.g. by heat sealing. In a variant, the guide piece can also have a frustoconical region interconnecting the two cylindrical regions 96 and 98b which participate in providing guidance, thus replacing the cylindrical region 98a. Given that while guiding the distributor element 64 in rotation, the guide piece 94 and the piece 104 are subjected to large mechanical forces, it is possible to provide ribs 108 to reinforce the central portion of the structure 80. To ensure that the guide piece 94 does not exert downward axial forces on the distributor element 64, an axial retaining member 110 is provided. As shown in Figures 8 and 9, the axial retaining member for the guide piece is a cylindrical peg 110 engaged in a cylindrical sheath 112 ,formed in the central portion of the guide piece 94, level with the cylindrical regions 96 and 98a,b. The peg 110 is provided at its end opposite from the end engaged in the sheath 112 with a head-forming shoulder 114 which bears against the carrier structure and, more particularly, against the plane top portion 104a of the piece 104 so as to hold the guide piece 94 axially. The peg 110 is fixed inside the sheath 112 in removable manner, e.g. by snap fastening. For snap-fastening purposes, the peg has an annular groove 116 (Figure 8) on one of its diameters for co-operating by engaging an annular bead 118 formed on the inside surface of the axial sheath 112 (Figure 9). The head 114 of the peg rests on the top portion 104a of the piece 104 via an annular surface 120. This configuration provides better contact by friction than would be obtained if the peg was placed with its head extending downwards towards the distributor element, since under such circumstances friction contact would be made via the snap-fastening. It is appropriate to observe that it is particularly simple to assemble the guide piece 94 and the peg 110, since it suffices to engage the guide piece in the housing 106 and to force the peg 110 into the axial sheath 112 until the two elements snap fasten together. The prior art guide piece (Figure 1) is made up of a plurality of parts and provision is made to mount a worm screw (not shown in Figure 1) on the cylinder 11 for meshing with one or more gearwheels of a gear train, thus considerably complicating the prior art guide means and assembly thereof compared with the guide means of the invention. The gear train is connected to the totalizer of the meter. In the invention, the gas meter includes in conventional manner a display.totalizer for displaying the volume of gas measured by the meter. In order to avoid overcrowding the figures, the totalizer is not shown. The guide piece 94 has a gearwheel 102 which serves to transmit rotary movement from the distributor element 64 to the totalizer via a gear train. Because of the recess 86 provided in the central portion of the carrier structure 80, the gearwheel 102 meshes with the other gearwheel 8 4 mounted on the pivot 82. This gearwheel co¬operates in turn with a third gearwheel 112 placed perpendicularly to the first two gearwheels and which is mounted on a stud 124 (Figure 8) formed on the outside portion of the branch 80b of the carrier structure 80. The gearwheel 122 co-operates in turn (not shown in the figures) with the display totalizer. The presence of the recesses 86, 90 and of the pivots 82, 88 on the central portion of the carrier structure serves advantageously to make it simple to mount the gearwheels of the gear train, and their symmetrical disposition as shown in Figures 7 to 9 makes it possible to mount the gearwheel 84 either on the pivot 82 or on the pivot 88 depending on the desired configuration. Another stud 126 formed on the outside portion of the branch 80a of the carrier structure 8 0 is also provided symmetrically to the stud 124 so as to receive the wheel 122 when the wheel 84 is mounted on the pivot 88. WE CLAIM : 1. A gas meter comprising a plurality of deformable diaphragm (28) measurement chambers (26), a distributor element (64) mounted to rotate about a "rotation" axis on distribution surface (42f) in which there are provided a plurality of orifices (44, 46, 48, 50) each of which is connected to a respective measurement chamber, said distributor element enabling gas to enter and to leave the measurement chambers in alternation during its rotary movement, and means for guiding said distributor element in rotation comprising firstly a guide piece (94) having at least a portion of generally elongate shape along the axis of rotation with two cylindrical regions (96, 98b) spaced a from each other, and secondly two bearings (104a, b) in which said cylindrical regions are mounted to rotate freely, the meter beind~characterized in that the guide piece (94) is a thermoplastic material and the cylindrical regions (96, 98b) are of different diameters 2. A gas meter as claimed in claim 1, wherein the larger diameter cylindrical region (96) is closer to the distributor element. 3. A gas meter as claimed in claim 1 or 2, wherein the guide piece has a frustoconical region interconnecting the two different-diameter cylindrical regions. 4. A gas meter as claimed in any one of claims 1 to 3,iwherein the guide piece (94) is in the form of a crank having one end constituted by the cylindrical regions (96, 98a, 8b) engaged in the bearings, and whose other end is constituted by finger (78) parallel to the axis of rotation and offset therefrom, which finger co-operates with a cavity (79) formed in the distributor element (64). 1 "3" 5. A gas meter as claimed in any one of claims 1 to 4, wherein the gas meter comprises a U-shaped carrier structure (80) whose inside faces towards the distributor element (64) so as to surround it, and supporting the guide piece, the elongate portion of said guide piece being engaged in a housing (106) provided in the structure via one end of said housing which is disposed at the same end as the distributor element, the be (104a, b) being arranged in side said housing. 6. A gas meter as claimed in claim 5, wherein the gas meter comprises a member (110) for axially retaining the guide piece. 7. A gas meter as claimed in claim 6, wherein the axial retaining member for the guide piece is a peg (110) engaged in an axial sheath (112) provided inside the guide piece (94) from its end opposite from the housing, said peg being fixed to said guide piece in removable manner and being provided on the outside of said sheath with a shoulder (114) forming a head which bears against the carrier structure so as to retain said guide piece axially. 8. A gas meter as claimed in claim 7, wherein the peg (110) is fixed to the inside of the sheath by snap fastening. 9. A gas meter as claimed in claim 8, wherein the peg (110) has an annular groove (116) on one of its diameters to co-operate with an annular bead (118) formed on the inside surface of the sheath (112). 10. A gas meter as claimed in claim 7, wherein the head (114) of the peg (110) bears against the carrier structure (80) by means of an annular surface (120) extending perpendicularly to the axis of rotation. 11. A gas meter as claimed in any one of claims 1 to 10, wherein the gas meter comprises a display counter, and the guide piece comprising a gearwheel (102) for transmitting the rotary movement of the distributor element (64) to said counter via a gear train. 12. A gas meter as claimed in claim 11, wherein the gearwheel (102) is disposed at the end of the elongate portion of the guide piece (94) which is closest to the distributor element, and is perpendicular to said portion. 13. A gas meter as claimed in claim 11, wherein the guide piece comprises a tumtable (100) which carries the gearwheel (102) on one of its faces. 14. A gas meter as claimed in claim 4 and 13, wherein the tumtable carries on its opposite face the finger (78) which co-operates with the distributor element (64). 15. A gas meter as claimed in claims 5 and 11, wherein the U-shaped structure (80) is constituted by a central portion parallel to the distribution surface (42f) and two side portions (80a, 80b) forming the branches of the U-shape, said central portion comprising a base (80c) of generally circular shape disposed in a plane PI extending parallel to the distribution surface and provided at its periphery with a collar (80d) disposed perpendicularly to said base in such a manner as to define a cavity (81) situated facing the distributor element and designed to receive its gearwheel (102). 16. A gas meter as claimed in claim 15, wherein the central portion of the U-shaped structure (80) comprises on either side of the base (80c), two regions (80e, 801) situated in a plane P2 parallel to the distribution surface (42f) and offset from the plane PI by a distance that is greater than the thickness of the gear wheel, one of said regions (801). carrying a pivot (82) capable of receiving another gearwheel (84) of the gear train, and recess (86) being provided in said base and in said collar so that the gearwheels can co-operate with each other. 17. A gas meter as claimed in claim 16, wherein the other region (80e) of the central portion carries a pivot (88) capable of receiving another gearwheel of the gear train, and another recess (90) being formed in the base (80c) and the collar (80d) on the side opposite to the first recess (86) so that the gearwheels can co-operate with each other. 18. A gas meter, substantially as hereinabove described and illustrated with reference to figures 2 to 9 of the accompanying drawings.

Documents:

in-pct-2000-0668-che abstract-duplicate.pdf

in-pct-2000-0668-che abstract.jpg

in-pct-2000-0668-che abstract.pdf

in-pct-2000-0668-che assignment.pdf

in-pct-2000-0668-che claims-duplicate.pdf

in-pct-2000-0668-che claims.pdf

in-pct-2000-0668-che correspondece-others.pdf

in-pct-2000-0668-che correspondece-po.pdf

in-pct-2000-0668-che description(complete)-duplicate.pdf

in-pct-2000-0668-che description(complete).pdf

in-pct-2000-0668-che drawings-duplicate.pdf

in-pct-2000-0668-che drawings.pdf

in-pct-2000-0668-che form-1.pdf

in-pct-2000-0668-che form-13.pdf

in-pct-2000-0668-che form-19.pdf

in-pct-2000-0668-che form-26.pdf

in-pct-2000-0668-che form-3.pdf

in-pct-2000-0668-che form-5.pdf

in-pct-2000-0668-che form-6.pdf

in-pct-2000-0668-che others.pdf

in-pct-2000-0668-che pct search report.pdf

in-pct-2000-0668-che pct.pdf