GB2475524A

GB2475524A - Sloped, gasket compressing wall in diaphragm pump hood to valve plate seal

Info

Publication number: GB2475524A
Application number: GB0920394A
Authority: GB
Inventors: Ying Lin Cai; Chao Fou Hsu
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-11-20
Filing date: 2009-11-20
Publication date: 2011-05-25
Anticipated expiration: 2029-11-20
Also published as: GB0920394D0; GB2475524B

Abstract

A reverse osmosis system diaphragm pump comprises chassis 11 having driven wobble members 13 and supporting pumping diaphragm 20, valve plate 40 and pump hood 50 screw 2 fixed to the chassis. The wobble inembers drive the diaphragm and pumping discs 30, pumping water from a hood inlet via valve plate passages 46, 43 and inlet 80 and outlet 70 valves to pressure chamber 4 and pump outlet 53. The diaphragm has inner 21 and outer 22a peripheral sealing lips receiving downward lips 402 of the valve plate which supports a gasket 60 for sealing to a simply stepped or tiered inner bore of the hood, an inclined portion (573 Fig. 19) of which applies a radial compression to the gasket and optionally the upper portion of the diaphragm lip. The compression increases axial gasket force (F) and improves sealing.

Description

LEAKAGE-PROOF CONTRIVANCE FOR UPPER HOOD OF

DIAPHRAGM PUMP

Field of the Present Invention

The present invention provides a leakage-proof contrivance for upper hood of diaphragm pump exclusively used in RO (Reverse Osmosis) Purification, particularly for one that can block and prevent the pressurized water of the pump upper hood from leaking into the associated motor so that the "water leakage drawback" incurred by the tiny water channel and worsened by "water hammer" effect can be thoroughly solved.

Background of the Invention

Currently, the compressing diaphragm pumps, which have been exclusively used with RO (Reverse Osmosis) purifier or RO purification system popularly, includes issued US Patents of 4396357, 4610605, 5476367, 5571000, 5615597, 5626464, 5649812, 5706715, 5791882, 5816133, 6048183, 6089838, 6299414, 6604909, 6840745, 6892624 and7083392 as well as issued Taiwan Patent 095122820. In which, the Taiwan Patent 095122820, which is applied by the inventor of the present invention and granted to be published, as shown in FIGS. 1 through 6, essentially comprises a motor 10 with an output shaft (not shown), a round upper hood chassis 11 with plural screw bores 12 disposed at peripheral thereof, three wobble roundels 13 with each threaded bores 14 therein, a diaphragm 20 of angles-rounded triangular form, three piston pumping disks 30 with three tiered bores 31 and three screws 32, a piston valve 40 on a piston base 401 of angles-rounded triangular form, a pump upper hood 50 with plural perforated holes 51 disposed at bottom peripheral thereof a sealing collar gasket 60 of angles-rounded triangular form, an anti-backflow plastic pad 70 and three valvular roundels 80 as well as plural bolts 2; by driving the bolts 2 through aligned corresponding perforated holes 51 at the pump upper hood 50 and screw bores 12 at the upper hood chassis 11, all the upper hood chassis 11, wobble roundels 13, diaphragm 20, piston pumping disks 30, valvular roundels 80, piston valve 40, sealing collar gasket 60, anti-backflow plastic pad 70 and pump upper hood 50 are orderly stacked and assembled as an integral entity (as shown in FIG. 3). Wherein said wobble roundels 13, which are evenly disposed in the upper hood chassis 11 in radial manner, are driven by the output shaft of the motor 10 to transform into alternately axial movements respectively; Said diaphragm 20 of angles-rounded triangular form, which is basically a triangle but all three angle tips are respectively rounded and entirely surrounded by an inner ring ridge 21 and an outer rim ridge 22 with outer lateral surface 222 and a top surface 221 (as shown in FIG. 2), includes an annular sealing groove 201 beset by the inner ring ridge 21 and outer rim ridge 22, three evenly disposed radial ridged ribs 23, three evenly distributed piston pumping zones 24 and three hollow shafts 25, wherein each said piston pumping zone 24 is defined by two flanked adjacent radial ridged ribs 23 and corresponding arc section of the inner ring ridge 21 (as shown in FIGS. 1 and 2); and each said hollow shaft is disposed in each piston pumping zone 24 with location relatively corresponding with each threaded borel4 in each wobble roundel 13 so that the diaphragm 20 can be firmly sandwiched by top three piston pumping disks 30 and bottom three wobble roundels 13 by means of running each screw 32 orderly via each tiered bore 31 in the piston pumping disks 30 and each corresponding hollow shaft 25 in each piston pumping zones 24 of the diaphragm 20 as well as each corresponding threaded borel4 of the each wobble roundel 13 respectively (as shown in FIGS. 2 and 5); Each said piston pumping disk 30 is securely fixed in each corresponding piston pumping zones 24 of the diaphragm 20 respectively by each screw 32 running through each corresponding tiered bore 31 thereof; Said piston valve 40, which is integrally molded on a piston base 401 of angles-rounded triangular form with three orientating ridges 47 to be securely positioned on the diaphragm 20, basically includes a central water discharge mount 41 and three peripheral water inlet mounts 44, wherein said piston base 401 of angles-rounded triangular form, which is basically a triangle but all three angle tips are respectively rounded and entirely surrounded by an annular sealing ridge 402 to beset in the corresponding annular sealing groove 201 of the diaphragm 20, has a rim top surface 403 over the annular sealing ridge 402; said water discharge mount 41, which is bowl-shaped profile disposed on the central top of the piston valve 40, has a central orientating hole 42 and three grouped water discharge openings 43 evenly distributed in three equivalent sectors; each said water inlet mount 44, which is integrally molded in partial-cut round shape in upside-down bowl-shaped profile in circumjacent contact the central water discharge mount 41, has a central orientating hole 45 and plural water inlet vents 46 evenly distributed in surrounding manner therein; each said orientating ridge 47, which is formed along the footing tangent line circumscribed both adjacent water inlet mounts 44, has an tangent surface 48 to serve as a positioning curb when the sealing collar gasket 60 stacks on the rim top surface 403 of the piston base 401(as the partially enlarged view of piston valve 40 shown in FIG. 2); Said sealing collar gasket 60, which is made of soft material in roughly angles-rounded triangular form to be disposed between the piston valve 40 and pump upper hood 50, has a top surface 61, a bottom surface 62 and an outer lateral surface 63; -.3-Said anti-backflow plastic pad 70, which is made of soft elastic material with a top clover-like disk of piano-convex profile in divided three-leaved shape, has a central orientating pin 71 downwardly disposed beneath the top disk so that the orientating pin 71 can be inserted into the orientating hole 42 in the water discharge mount 41 of the piston valve 40 with the three-leaved top disk thereof closely attach over three grouped water discharge openings 43 in respective three sector; Each said valvular roundels 80, which is made of soft elastic material with a top disk of piano-convex profile, has a central orientating pin 81 upwardly disposed on the top disk so that the orientating pin 81 can be inserted into the orientating hole 45 in each corresponding water inlet mount 44 with the top disk closely attach and block all water inlet vent 46 in each corresponding water inlet mount 44 so that a preliminary low-pressured chamber 3 is created between each valvular roundel 80 and each corresponding piston pumping disk 30 with one connection end of the low-pressured chamber 3 being inter-fluent with the water discharge openings 43 in each corresponding water discharge mount 41 (as shown in FIGS. 4, 5 and 6); and Said pump upper hood 50, which is a hollow body with bottom open, has a water input orifice 52 and a water output orifice 53 respectively disposed on each opposed top peripheral thereof as well as plural perforated holes 51 disposed at bottom peripheral thereof (as shown in FIGS. 1 and 3); wherein an inner tiered cavity 54 internally including an internal lower tiered brim 541 with a horizontal bottom surface 542 and a vertical wall 543 as well as an upper tiered brim 544 with a horizontal bottom surface 545 and a vertical wall 546 is inwardly created from the opening side of the pump upper hood 50 so that the horizontal bouom surface 542 and vertical wall 543 of the lower tiered brim 541 can closely attach the top surface 61 and outer lateral surface 63 of the sealing collar gasket 60 in match manner while the horizontal bottom surface 545 and vertical wall 546 of the upper tiered brim 544 can closely attach the top surface 221 and outer lateral surface 222 for the outer rim ridge 22 of the diaphragm20 in match manner (as the partially enlarged view of tiered groove 54 shown in FIG. 2); an innermost annular pit 55 is outwardly created from the internal top wall of the pump upper hood 50; and an intensive high-pressured chamber 4 is created by the internal space encompassed by the inner wall of the annular pit 55 and the top surface of the water discharge mount 41 in the piston valve 40 when the bottom rim surface of the annular pit 55 closely attach the upper rim surface of the water discharge mount 41 in the piston valve 40 (as shown in FIGS. 4 and 5).

Please refer to fIGS. 4 through 6, which show the pumping operation of aforesaid conventional diaphragm pump. Firstly, when motor 10 is powered on, the tap water W, which comes from the water input orifice 52 of the pump upper hood 50 to push open the valvular roundel 80 in the water inlet mount 44, flows into the low-pressured chamber 3 via the water inlet vent 46 in the water inlet mount 44 of the piston valve 40 (as arrowheads shown in FIGS. 4 and 5); Secondly, upon each wobble roundel 13 being orderly driven by the driving power from the output shaft of the motor 10, each corresponding piston pumping disk 30 will move up and down in each corresponding piston pumping zone 24 of the diaphragm 20 so that the tap water W in the low-pressured chamber 3 will be preliminarily pumped up to water pressure of 80psi--iOOpsi as become pressurized water Wp; Thirdly, the pressurized water Wp is enabled to push open the anti-backflow plastic pad 70 over the water discharge mount 41 of the piston valve 40 so that the pressurized water Wp can flow into the high-pressured chamber 4 via the water discharge openings 43 of the water discharge mount 41; and Finally, the pressurized water Wp is pumped out the high-pressured chamber 4 and expelled out the diaphragm pump via the water output orifice 53 (as arrowhead shown in FIG. 6) for being used in the filter cartridge in the RU (Reverse Osmosis) purifier or RO purification system with required water pressure.

For further retrospectively examining the pumping operation of aforesaid conventional diaphragm pump described above, please refer to FIGS. 4, 6 through 10.

Upon each piston pumping disk 30 orderly moving up and down in each corresponding piston pumping zone 24 of the diaphragm 20, each corresponding sector of the diaphragm 20 will follow an orderly up and down movement (as shown in FIG. 6) and a vertical force Fv is incurred from the rim top surface 403 of the piston base 401 on the piston valve 40 to continuously exert on the bottom surface 62 of the sealing collar gasket 60 (as shown in FIG. 7) so that both top surface 61 and bottom surface 62 of the sealing collar gasket 60 will be continuously suffered squeezing stress of upwards vertical force Fv from the rim top surface 403 of the piston base 401 and the downwards vertical force Fv from horizontal bottom surface 542 for the lower tiered brim 541 of the tiered cavity 54 (as shown in FIG. 8); Because three wobble roundels 13 orderly move up and down three times for each revolution of the motor 10, the sealing collar gasket 60 will be orderly suffered squeezing stress of vertical forces Fv three times. Normally, the motor 10 runs 700 revolutions per minute (700 RPM) so that the sealing collar gasket 60 will be suffered squeezing stress of vertical forces Fv 2100 times (700x3 = 2100). Under such impact of squeezing stress in high frequency, the original thickness H defined between the top surface 61 and bottom surface 62 of the sealing collar gasket 60 will be getting thinner into a thinned thickness h less than the original thickness H (as shown in FIGS. 7 and 8) so that a gap G in difference from the original thickness H deducting the thinned thickness h is created either between the rim top surface 403 of the piston base 401 on the piston valve and the bottom surface 62 of the sealing collar gasket 60 (as shown in FIG. 9) or between the horizontal bottom surface 542 of the lower tiered brim 541 at the tiered cavity 54 of the pump upper hood 50 and the top surface 61 of the sealing collar gasket 60 (as shown in FIG. 10).

Because both of diaphragm 20 and pump upper hood 50 are made of rigid plastic material instead of soft rubber material, they can not closely attach each other. Besides, a clearance 6 will be created between the outer lateral surface 222 of outer rim ridge 22 on the diaphragm 20 and the vertical wall 546 of the upper tiered brim 544 on the tiered cavity 54 after certain long time operation (as shown in FIGS. 9 and 10). Because both of the gap G edge and clearance 6 edge abut each other in inter-fluent maimer, a tiny water channel is created throughout the gap G and clearance 5.

Besides, for all convention diaphragm pumps, which are used in the RU (Reverse Osmosis) purifier or RU purification system, the water input orifice 52 of the pump upper hood 50 is connected to the pipe joint J of the tap water for a reservoir tower (as hypothetic line shown in FIG. 4). Whereas the reservoir tower is always set up on the upmost roof of the building, a rather drop height of the reservoir tower and the diaphragm pump may create a water hammer Wg effect in all probability when the motor 10 turns into ON or OFF instance. Since the gap G due to thinning of the sealing collar gasket 60 and the clearance 6 created between the outer lateral surface 222 of outer rim ridge 22 on the diaphragm 20 and the vertical wall 546 of the upper tiered brim 544 on the tiered cavity 54 build a tiny water channel because both of the gap G edge and clearance S edge abut each other in inter-fluent manner, the tap water W, which is affected by the water hammer Wg effect and come from the water input orifice 52 of the pump upper hood 50, will immediately flow into the gap G between the rim top surface 403 of the piston base 401 on the piston valve 40 and the bottom surface 62 of the sealing collar gasket 60 (as shown in FIG. 9) or the gap G between the horizontal bottom surface 542 of the lower tiered brim 541 at the tiered cavity 54 of the pump upper hood 50 and the top surface 61 of the sealing collar gasket 60 (as shown in FIG. 10); Then, the water hammer Wg affected tap water W will flow into space between the pump upper hood 50 and upper hood chassis 11 via the clearance a created between the outer lateral surface 222 of outer rim ridge 22 on the diaphragm 20 and the vertical wall 546 of the upper tiered brim 544 on the tiered cavity 54 (as shown in FIG. 10); Thereby, a resultant "water leakage drawback" is incurred in the pump upper hood 50. The "water leakage drawback" incurred in the pump upper hood 50 not only causes the local abnormal pressure to result in decrease of overall pumping efficiency but also contaminates and destroys some external components in the associated RO (Reverse Osmosis) purifier or RO purification system with even worse result in shutting down the integral system by burning the motorlO as leakage getting into the motorlO via the space between the wobble roundels 13 and upper hood chassis 11 (as shown in FiG. 9).

For solving the "water leakage drawback" aforesaid, some diaphragm pump manufacturers introduce an improved model as shown in FIGS. 11 and 12. Basing on the conventional diaphragm pump disclosed in the previous paragraph of "BACKGROUND OF THE INVENTION" in association with (FIGS. I through 6), the improved model of diaphragm pump comprises same components as those components in the prior art of Taiwan Patent 095122820 except following alteration that the original outer rim ridge 22 with a top surface 223 and an outer lateral surface 224 in the diaphragm 20 is altered into an outer rim ridge 22a with increasing the height thereof, and the original tiered cavity 54 in the pump upper hood 50 is altered into a simple cavity 56 without tiered brim but having a horizontal bottom surface 561 and an inner vertical wall 562 thereof wherein, the height for the outer lateral surface 224 of the outer rim ridge 22a almost equals that for the vertical wall 562 of the simple cavity 56 so that the top surface 223 of the outer rim ridge 22a on the diaphragm 20 is flush with the top surface 61 of the sealing collar gasket 60 and closely attach on the horizontal bottom surface 561 of the simple cavity 56, whereas the outer lateral surface 224 of the outer rim ridge 22a just closely attach the inner vertical wall 562 of the simple cavity 56 when the stacked entity of the diaphragm 20, piston valve and sealing collar gasket 60 is inset in the simple cavity 56 of the pump upper hood 50 (as the partially enlarged view shown in FIG. 12). Through our practical life test under normal weather condition for certain time, a gap C is still formed between the horizontal bottom surface 561 of the simple cavity 56 and the top surface 61 of the sealing collar gasket 60, which has been thinned by continuously pumping impact (as shown in FiG. 13), so that the "water leakage drawback" can not really solved because the water hammer Wg affected tap water W, which is come from the water input orifice 52 of the pump upper hood 50, still firstly flows into the gap G between the horizontal bottom surface 561 of the simple cavity 56 and the top surface 61 of the sealing collar gasket 60 (as shown in FIG. 13) and then flows into the space between the pump upper hood 50 and upper hood chassis 11 to leak out via the clearance 5 created between the outer lateral surface 224 of outer rim ridge 22a on the diaphragm 20 and the vertical wall 562 of the simple cavity 56.

The foregoing facts described reflect that the altered conventional diaphragm pump provides a false illusion that whose new product seemingly appears in no "water leakage drawback" manner in the begiiming stage but with failure in practical life test under normal weather condition. Inferentially, the "water leakage drawback" in the altered conventional diaphragm pump aforesaid will be getting worse under adverse weather condition such as tropical or frigid zones due to drastic hot-expansion and cold-shrink effect as well as expedited aging effect happening in the sealing collar gasket 60.

Inevitably, the altered conventional diaphragm pump aforesaid has always to be replaced due to malfunction before the guarantee expiry. Thus, not only the goodwill is harmfully affected but also the overall cost in fabrication and fringe cost in maintenance are increased. Therefore, how to work out an effective and simple way to solve the "water leakage drawback" in the conventional diaphragm pumps becomes a critical issue to deal with urgently.

Summary of the Invention

After having addressing and deeply studied the forgoing "water leakage drawback" happened in the conventional diaphragm pimp, an effective and simple solving means is eventually worked out by the applicant of the present invention via painstaking research and development. Therefore, the primary object of the present invention is to provide a leakage-proof contrivance for upper hood of diaphragm pump by modifying the original vertical wall of the internal lower tiered brim in the tiered cavity of the conventional pump upper hood into a sloped wall; Thus, when stacked assembly of sealing collar gasket, piston valve and diaphragm is inset into the tiered cavity of the pump upper hood in closely attachment manner, the outer lateral surface of the sealing collar gasket will immediately cause a horizontal force incurred by the sloped wall of the lower tiered brim in the tiered cavity; Meanwhile, by the confinement from the circumferential surface of the -10-orientating ridge on the piston valve, the sealing collar gasket will be slantwise squeezed and vertically deformed to produce normal outwards stress in both upwards and downwards manners. By both normal outwards stresses of upwards and downwards manners, when the sealing collar gasket is interposed between the pump upper hood and piston valve, the top surface and bottom surface of the sealing collar gasket can respectively inset in the tiered cavity of the pump upper hood and the piston base of the piston valve in much more closely attachment manner to block and prevent the pressurized water from leaking out of the diaphragm pump.

The other object of the present invention is to provide a leakage-proof contrivance for upper hood of diaphragm pump by modifying the original simple cavity with a horizontal bottom surface and an inner vertical wall of the conventional pump upper hood into a simple cavity with a sloped wall in addition to the horizontal bottom surface and an inner vertical wall thereof such that one edge of the sloped wall abuts with the horizontal bottom surface while the other edge of the sloped wall abuts with the vertical wall 1 5 respectively; Thus, when stacked assembly of sealing collar gasket, piston valve and diaphragm is inset into the tiered cavity of the pump upper hood in closely attachment manner, the top surface and outer lateral surface near the top surface will be suffered a compressing confinement from the sloped wall of the simple cavity so that the outer lateral surface of the sealing collar gasket will be indirectly affected and immediately incurred to cause a horizontal force; Meanwhile, by the confinement from the circumferential surface of the orientating ridge on the piston valve, the sealing collar gasket will be slantwise squeezed and vertically deformed to produce normal outwards stress in both upwards and downwards manners. By both normal outwards stresses of upwards and downwards manners, when the sealing collar gasket is interposed between the pump upper hood and piston valve, the top surface and bottom surface of the sealing collar gasket can respectively inset in the simple cavity of the pump upper hood and the piston base of the piston valve in much more closely attachment manner to block and prevent the pressurized water from leaking out of the diaphragm pump.

Brief Description of the Drawings

FIG. 1 is a exploded perspective view showing the conventional diaphragm pump

of the prior art.

FIG. 2 is a sectional view showing the conventional diaphragm pump of the prior art.

FIG. 3 is a assembly perspective view of the conventional diaphragm pump.

FIG. 4 is a sectional view taken along the line 4-4 of the FIG. 3.

FIG. S is a sectional view taken along the line 5-S of the FIG. 3.

FIG. 6 is a sectional view showing the pumping operation of the conventional diaphragm pump.

FIG. 7 is a sectional schematic view showing the sealing collar gasket suffered from normal stress between pump upper hood and piston valve during pumping operation of the conventional diaphragm pump.

FIG. 8 is a sectional schematic view showing the sealing collar gasket deformed to strain after having been suffered from normal stress between pump upper hood and piston valve during pumping operation of the conventional diaphragm pump.

FIG. 9 is a partially enlarged view taken from the left corner A of the FIG. 6. -12-

FIG. 10 is a partially enlarged view taken from the right corner B of the FIG. 6.

FIG. 11 is a sectional schematic view for another type of the conventional diaphragm pump.

FIG. 12 is a sectional assembly view for another type of the conventional diaphragm pump.

FIG. 13 is a partially enlarged view taken from the right corner C of the FIG. 12.

FIG. 14 is a sectional schematic view showing the exploded components for the first exemplary embodiment of the present invention.

FIG. 15 is a sectional schematic view showing the assembled components for the first exemplary embodiment of the present invention.

FIG. 16 is a partially enlarged view taken from the right corner D of the FIG. 15.

FIG. 17 is a sectional schematic view showing the exploded components for the second exemplary embodiment of the present invention.

FIG. 18 is a sectional schematic view showing the assembled components for the second exemplary embodiment of the present invention.

FIG. 19 is a partially enlarged view taken from the right corner E of the FIG. 18.

Detailed Description of the Preferred Embodiments

Please refer to FIGS. 14 through 16, which show the first exemplary embodiment for the "leakage-proof contrivance for upper hood of diaphragm pump" of the present invention. Basing on the conventional diaphragm pump disclosed in the previous paragraph of "BACKGROUND OF THE INVENTION" in association with (FIGS. 1 -13-through 6), the present invention comprises same components as those components in the prior art of Taiwan Patent 095122820 except following modification that the original vertical wall 543 of the internal lower tiered brim 541 in the tiered cavity 54 of the conventional pump upper hood 50 is modified into a sloped wall 547 (as the partially enlarged view shown in FIG. 14). The structural advantage in the pumping operation for the first exemplary embodiment of the "leakage-proof contrivance for upper hood of diaphragm pump" in the present invention can be manifested as below: Firstly, stack the piston valve 40 over the diaphragm 20 in assembled manner; Secondly, sleeve the sealing collar gasket 60 over the rim top surface 403 of the piston base 401 on the piston valve 40 to have both of the sealing collar gasket 60 and piston valve 40 with diaphragm 20 become a preliminary integral entity; and Finally, inset the preliminary integral entity of the sealing collar gasket 60 and piston valve 40 with diaphragm 20 into the tiered cavity 54 of the pump upper hood 50 in closely attachment manner to become a final integral entity (as shown in FIG. 15). At this moment, the outer lateral surface 63 of the sealing collar gasket 60 will immediately cause a horizontal force Fh incurred by the sloped wall 547 of the lower tiered brim 541 in the tiered cavity 54 (as arrowhead shown in FIG. 16); Meanwhile, by the confinement from the circumferential surface 48 of the orientating ridge 47 on the piston valve 40, the sealing collar gasket 60 will be slantwise squeezed and vertically deformed to produce normal outwards stress F in both upwards and downwards manners (as half-solid arrowhead shown in FIG. 16). By both normal outwards stresses F of upwards and downwards manners, when the sealing collar gasket 60 is interposed between the pump upper hood 50 and piston valve 40, the top surface 61 and bottom surface 62 of the sealing collar gasket 60 can respectively inset in the tiered cavity 54 of the pump upper hood 50 and the piston base 401 of the piston valve 40 in much more closely attachment -14 -manner to block and prevent the pressurized water Wp from leaking out of the diaphragm pump.

Referring to FIGS. 17 to 19, which show the second exemplary embodiment for the "leakage-proof contrivance for upper hood of diaphragm pump" of the present invention. Basing on the improved model of the conventional diaphragm pump disclosed in the previous paragraph of "BACKGROUND OF THE INVENTION" in association with (FIGS. 11 and 12), the present invention comprises same components as those components in the prior art of the improved model aforesaid except following modification that the original simple cavity 56 with a horizontal bottom surface 571 and an inner vertical wall 572 of the conventional pump upper hood 50 is modified into a simple cavity 57 with a sloped wall 573 in addition to a horizontal bottom surface 571 and an inner vertical wall 572 thereof such that one edge of the sloped wall 573 abuts with the horizontal bottom surface 571 while the other edge of the sloped wall 573 abuts with the vertical wall 572 respectively; Besides, the original outer rim ridge 22 with a top surface 223 and an outer lateral surface 224 in the diaphragm 20 is modified into an outer rim ridge 22a with increasing the height thereof such that the height for the outer lateral surface 224 of the outer rim ridge 22a is slightly less than that for the vertical wall 572 of the simple cavity 57 so that the space encompassed by the horizontal bottom surface 571 and vertical wall 572 of the simple cavity 57 is just big enough to accommodate the top surface 223 and outer lateral surface 224 of the outer rim ridge 22a on the diaphragm 20 to closely attach therein.

The structural advantage in the pumping operation for the second exemplary embodiment of the "leakage-proof contrivance for upper hood of diaphragm pump" in the present invention can be manifested as below: Firstly, stack the piston valve 40 over the diaphragm 20 in assembled manner; Secondly, sleeve the sealing collar gasket 60 over the rim top surface 403 of the piston base 401 on the piston valve 40 to have both of the sealing collar gasket 60 and piston valve 40 with diaphragm 20 become a preliminary integral entity; and Finally, inset the preliminary integral entity of the sealing collar gasket 60 and piston valve 40 with diaphragm 20 into the simple cavity 57 of the pump upper hood 50 in closely attachment manner to become a final integral entity (as shown in FIG. 18). At this moment, the top surface 223 and outer lateral surface 224 near the top surface 223 will be suffered a compressing confinement from the sloped wall 573 of the simple cavity 57 so that the outer lateral surface 63 of the sealing collar gasket 60 will be indirectly affected and immediately incurred to cause a horizontal force Fh (as arrowhead shown in FIG. 19); Meanwhile, by the confinement from the circumferential surface 48 of the orientating ridge 47 on the piston valve 40, the sealing collar gasket 60 will be slantwise squeezed and vertically deformed to produce normal outwards stress F in both upwards and downwards manners (as half-solid arrowhead shown in FIG. 19). Likewise, as in the first exemplary embodiment, by both normal outwards stresses F of upwards and downwards manners, when the sealing collar gasket 60 is interposed between the pump upper hood 50 and piston valve 40, the top surface 61 and bottom surface 62 of the sealing collar gasket 60 can respectively inset in the simple cavity 57 of the pump upper hood 50 and the piston base 401 of the piston valve 40 in much more closely attachment manner to block and prevent the pressurized water Wp from leaking out of the diaphragm pump.

Basing on the disclosure heretofore and experimental test, the applicant of the present invention proves that the present invention surely solve the "water leakage drawback" issue without any bad side-effect after practical life test, which has valuable industrial applicability. Especially, the solving scenario contrived by the present invention -16-is simple with innovative novelty beyond the obviousness of the prior arts, which meet the basic patentable criterion. -17-