in describing a preferred embodiment of the invention illustrated in the drawings , specific terminology will be resorted to for the sake of clarity . however , the invention is not intended to be limited to the specific terms so selected , and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose . with reference to fig1 - 5 , reference 10 is used to generally designate the water distributing hose comprising the instant invention . the hose 10 basically comprises three tubular chambers . as oriented in fig2 the water distributing hose 10 comprises a main first fluid passage or water - receiving chamber 12 . adjacent to this passage and sharing a common wall 18 is an intermediate chamber or second fluid passage 14 . adjacent to passage 14 and sharing a common wall 20 , which , as shown , is essentially parallel to wall 18 , is an outer low pressure chamber or third fluid passage 16 . as can be seen , the three fluid passages are arranged one next to the other in a generally parallel relationship throughout the length of the hose . in use , the first fluid chamber 12 is connected to a source of pressurized water . this can be effected , for example , by connecting the first fluid passage 12 at one end of hose 10 to a suitable fitting 21 in main 24 . the other end 11 of the hose 10 is closed off to prevent escape of the water entering the hose . such an arrangement has been generally illustrated in fig1 wherein the hose 10 is illustrated next to rows of vegetables in a large field . it will be appreciated that such an arrangement is also equally adaptable for use in greenhouses and home gardens . with reference to fig4 which shows the various walls or layers partially cut away to reveal a fragmentary view of the different fluid passages constituting the hose , a wall 30 , which defines the first fluid passage 12 , is provided with a series of fluid - passing openings or orifices 32 therein , normally spaced a few inches to several feet apart throughout the full length of the hose . the orifices or first fluid - passing openings 32 are positioned so that they form a means of fluid communication between the first fluid passage 12 and the second fluid passage 14 . as such , the first fluid - passing openings 32 are located somewhere within the common wall 18 defined between the first fluid passage 12 and the second fluid passage 14 . in like manner , the second fluid passage 14 contains a further set of fluid - passing openings or orifices 34 to form a means of fluid communication between the second fluid passage 14 and the third fluid passage 16 . thus , the second fluid - passing openings 34 are positioned somewhere along the common wall 20 defined between the second and third fluid passages 14 and 16 . the second fluid - passing openings 34 generally have substantially lesser spacing between them than the spacing formed between the first fluid - passing openings 32 . in actual practice , the spacing of the second fluid - passing openings 34 can vary from a few inches up to several feet . the first and second fluid - passing openings 32 and 34 are preferably round and precisely formed by punching , lasers , or other suitable means to give uniform flow emission therethrough . the openings 32 and 34 are made in wall members 18 and 20 , which are generally of uniform wall thickness in the immediate vicinity surrounding the openings . therefore , the openings essentially function hydraulically as a true orifice , which has a theoretical emission rate , wherein doubling the pressure loss across the orifice increases the emission rate by 1 . 414 times . finally , the third fluid passage 16 contains a series of longitudinally spaced fluid - passing openings 36 to provide fluid communication between the third fluid passage and atmosphere . the sizes of the discharge fluid - passing openings 36 are such that they are essentially free flowing with substantially no flow resistance across the discharge openings . in addition , the openings 36 can be several times as large as the first and second fluid - passing openings . in a preferred embodiment , the fluid - passing openings 32 , 34 and 36 are defined in layers or walls that are essentially parallel with each other . also , the openings are arranged in the layers so that the openings all lie in essentially a single plane that is substantially perpendicular to any of the layers . in terms of relative size , the first fluid - passing openings 32 as well as the second fluid - passing openings 34 are typically on the order of 0 . 015 to 0 . 025 inches in diameter , whereas the third fluid - passing openings 36 are typically on the order of 0 . 025 to 0 . 065 inches in diameter . in a preferred embodiment of the hose , the first fluid passage 12 has a diameter of about 0 . 630 inches while the second fluid passage 14 has a generally trapezoidal cross section having a height h of about 0 . 085 and a width at the base of about 0 . 220 inches with the discharge fluid passage 16 having a generally rectangular cross section of about 0 . 014 ( height )× 0 . 080 ( width ) inches . at the same time , the first fluid - passing openings 32 are spaced approximately four feet apart , the second fluid - passing openings 34 are spaced eight inches apart and the outer openings 36 are spaced eight inches apart with each opening 36 being located intermediate between , but spaced from , a pair of openings 34 . finally , the inner and intermediate openings 32 and 34 have a diameter of about 0 . 021 inches whereas the outer openings 36 have a diameter of about 0 . 062 inches . with the hose in this configuration , water is typically introduced into the first fluid passage 12 at about 6 psi . as the water from the first fluid passage 12 passes through the first fluid - passing opening 32 into the second fluid passage 14 , there is a pressure drop of approximately 4 . 5 psi so that the pressure in the second fluid passage 14 is approximately 1 . 5 psi . in general , the pressure drop from the first fluid passage 12 to the intermediate passage 14 must be at least 25 % of the pressure in the first fluid passage . as water from the second fluid passage 14 passes through the second fluid - passing openings 34 , there is a further , but slight , pressure drop of approximately 0 . 13 psi so that the pressure within the third fluid passage 16 is approximately 1 . 37 psi at a point adjacent to the second fluid - passing openings 34 . the flow rate for the preferred embodiment is about 0 . 5 gallons per minute per 100 feet of hose 10 . in constructing the hose 10 , the second fluid passage 14 is of a relatively small cross - sectional area , as compared to that of the first fluid passage 12 , so as to produce sufficient friction to the flow of water , whereby a major portion of the water flowing through each of the first fluid - passing openings 32 will tend to flow through the second fluid - passing openings 34 in the immediate vicinity of each particular first fluid - passing opening 32 . this vicinity will normally consist of one - half the length of one second fluid passage section ( hereafter defined ). in this manner , there will be a minimum flow of water along the second fluid passage , thereby tending to cause a uniform flow or discharge of water through the openings 34 along the length of the hose 10 . one second fluid passage section is defined as that length of hose between the midpoints of adjacent first fluid - passing openings 32 . in other words , ideally , the second fluid passage geometry should be optimized to minimize the viscous friction pressure loss in any one second fluid passage section , and yet substantially eliminate fluid flow between any two adjacent second fluid passage sections , even should a static fluid pressure head exist between any two second fluid passage sections , such as caused by placement on a slope . as the water passes laterally along the third fluid passage 16 from the second fluid - passing openings 34 to the adjacent discharge fluid - passing openings 36 on either side , there is a further pressure loss of approximately 1 . 37 psi due to friction created as water passes through the small third fluid passage 16 so that the pressure adjacent to the discharge fluid - passing openings is negligable ( such as a 1 &# 34 ; head of water or less ). therefore , the water actually drips out through the apertures 36 under substantially quiescent conditions under almost no outward pressure . the pressure drop loss between an aperture 34 and its nearest outlet 36 within the fluid passage 16 depends on the width and height of the passage , the length of the passage between its inlet 34 and its outlet 36 , and the rate of water passing through it . an important function of the third fluid passage 16 is to increase the pressure within the second fluid passage . the cross section of the third fluid passage 16 is of a small enough size to frictionally restrict the flow , causing a pressure loss through said passage . in the preferred embodiment , this pressure loss occurs within the third fluid passage 16 between each second fluid - passing opening 34 and the nearest discharge fluid - passing opening 36 on each side , the pressure loss being approximately 25 % of the starting pressure in the first fluid passage 12 , thereby creating a substantial back pressure to raise the pressure in the second fluid passage 14 to approximately 1 . 5 psi . this substantial pressure in the second fluid passage 14 enables the hose to function properly even over sharp variations in the soil level , such as a mound . since the preferred embodiment has approximately 1 . 5 psi at all second fluid - passing openings 34 , which are only 4 &# 34 ; from their adjacent discharge fluid - passing openings 36 , the discharge fluid - passing openings 36 continue to flow substantially uniformly even over sharp changes in elevation , such as a mound of soil 20 &# 34 ; high . when field conditions are such that a greater height in mounds of soil are encountered , a hose with smaller cross section in the third fluid passage 16 can be used to frictionally create a higher back pressure against the second fluid passage 14 , thereby providing the pressure needed in the second fluid passage 14 to give relatively uniform irrigation over mounds or sharp changes in elevation of 3 feet or more . the higher 1 . 5 pound pressure in the second fluid passage also helps the flow uniformity when the field has a long but reatively uniform slope over the length of the hose . in the present invention , the larger openings 36 do not substantially affect the flow rate . water emerging from these openings actually drips out under virtually no pressure . this is to be contrasted against certain prior art hoses that use multiple fluid transmission chambers , such as described previously in connection with chapin &# 39 ; s u . s . pat . no . re . 28 , 095 , where a particular ratio of the total area of the inner openings to the total area of the discharge openings is employed to control the flow , and flow is governed by the fluid passing through the various openings . in the present invention , however , because of the provision of the relatively small cross section of the third fluid passage 16 , and the relatively large discharge fluid - passing openings 36 , the flow comes out of the outlets in a drip rather than a small squirt as is often found in the prior art . to achieve the no - squirt feature of this invention , the area of each discharge fluid - passing opening 36 should be large enough to allow its desired flow rate to pass through the opening without a substantial pressure loss across the opening . generally , the maximum pressure loss across the discharge fluid - passing openings 36 without forming a squirt ranges from approximately 1 . 2 &# 34 ; head of water for a 0 . 062 &# 34 ; diameter opening to approximately a 4 &# 34 ; head of water for a 0 . 018 &# 34 ; diameter opening . in order for the fow from the discharge fluid - passing opening to emit as a drip , wherein the flow through the discharge fluid - passing opening essentially remains in contact with the exterior of the hose until it falls onto the soil adjacent to the discharge fluid - passing opening , the flow rates per opening should not exceed : 0 . 68 g . p . h . ( gallons per hours ) for a 0 . 062 &# 34 ; diameter opening ; 0 . 16 g . p . h . for a 0 . 025 &# 34 ; diameter opening ; and 0 . 12 g . p . h . for a 0 . 018 &# 34 ; diameter opening . thus , the parameters of hose design according to the present invention should preferably be selected to provide the desired flow rate through the discharge fluid - passing openings 36 . discharge fluid - passing openings 36 of the same diameter as the first fluid - passing openings 32 and the second fluid - passing openings 34 can be used in the present invention . the combination can give the same advantages of higher pressure in the second fluid passage , but the flow is apt to pass through the discharge fluid - passing opening 36 as a squirt rather than a drip , especially in hoses that are designed for the higher flow rates and , as such , is not desirable . as diagrammatically shown in fig4 the first fluid - passing openings 32 are much more widely spaced apart than either the second or discharge fluid - passing openings 34 and 36 . in fact , in a preferred embodiment , there are 6 times as many more second fluid - passing openings than there are first fluid - passing openings . as a practical matter , the ratio of the first to second fluid - passing openings can vary from a ratio of an equal number of first to second openings to one first to twelve or more second openings , depending on fluid - passing opening diameters . the spacing of the discharge openings can be any desired spacing according to soil and crop needs but preferably there are at least as many discharge openings as there are second openings . the total area of the discharge fluid - passing openings is greater than the total area of the first fluid - passing openings by a ratio of at least 3 : 1 and the total area of the second fluid - passing openings is greater than the total area of the first fluid - passing openings by a ratio of at least 1 . 5 : 1 . of additional significance is the placement of the various openings relative to each other . the first fluid - passing openings 32 are placed throughout the longitudinal length of the hose preferably along the center of the dividing wall 18 in a straight line parallel to the longitudinal axis formed by the first fluid passage 12 . in turn , the second fluid - passing openings 34 are positioned one next to the other preferably along the center of the intermediate layer 20 along a line likewise parallel to the longitudinal axis of the first fluid passage 12 . the openings 34 , which in a preferred embodiment are about eight inches apart , are positioned askew relative to the openings 32 in order to prevent direct in line communication between these openings . finally , the openings 36 also are spaced eight inches apart and are positioned so that one opening 36 is intermediate relative to any adjacent openings 34 . thus , it can be seen that the spacing between the openings 34 and between the discharge openings 36 is the same . in this way , each opening 36 can be supplied by the intermediate opening 34 located on either side . if the portion of the third fluid passage on one side of a discharge opening should become clogged by excess foreign particles in the water , then that opening would still receive water from the third fluid passage portion on the other side . in use , water , normally under a pressure of 6 psi is introduced into the water passage defined by the first fluid passage 12 . upon a filling of the inner water passage , the water , along the length of the first fluid passage 12 , flows through the first fluid - passing openings 32 at approximately an equal rate along the length of the hose 10 . the water then moves from each first fluid - passing opening 32 along the intermediate flow passage , defined by the second fluid passage 14 . the water then moves through the second fluid - passing openings 34 within the outer fluid passage defined by the third fluid passage 16 to the outlets 36 as a slow drip discharge . fig5 illustrates the directions of flow through the various fluid - passing openings . the section 35 of the third fluid passage between the second fluid - passing opening 34a and the discharge fluid - passing opening 36a acts as a discharge fluid passageway , wherein the flow moves through the discharge passageway 16 from the second fluid - passing opening 34a toward the discharge fluid - passing opening 36a and , at the same time , the flow also moves through the discharge passageway 35 &# 39 ; from the second fluid - passing opening 34a toward the discharge fluid - passing opening 36b . from the accompanying drawings , it can be appreciated that the first fluid passage 12 , formed by wall member 30 , becomes circular when pressurized , forming a round tube essentially free of internal partitions or other obstructions that would provide additional surfaces in the flow channel causing more loss of pressure due to friction , as well as making the hose more difficult to collapse for storage and shipment . as the hose is installed in the field , it is preferable to orient the hose so that the second and third fluid passages 14 and 16 are located on top of the first fluid passage 12 so that any foreign particles in the water would tend to settle to the bottom of the hose 12 rather than on the first fluid - passing openings 32 . while a 6 psi inlet water pressure is used to illustrate operation of the preferred embodiment , this invention will operate at inlet water pressures ranging from 2 psi to 60 or more psi , depending on the strength of wall 30 , fluid - passing opening sizes , ratios , etc . as can be seen with reference to fig3 one method of producing the hose 10 involves provision of a single sheet or flat strip 40 which is joined back upon itself as at 44 and seamed by heat sealing to create the first fluid passage 12 with the remaining portion of the layer 40 being joined to itself as at point 46 also by heat sealing to create the second fluid passage 14 . to complete the structure , a strip or layer of material 42 is laid across the outer surface of the second fluid passage 14 about the full length of the hose . as can be seen in fig3 and 4 , the layer 42 has two longitudinal edges 48 and 50 . near the ends of each of the edges , the strip 42 is secured to the outer surface of the intermediate layer by heat sealing to form a pair of spaced , longitudinally - extending seams . in this way , the outer chamber 16 is formed . a convenient way of making said seals is to place two continuous narrow ribbons 52 and 54 of hot melted polyethylene parallel with each other between the layers 20 and 42 , where the narrow ribbons also form the third fluid passage 16 into substantially a rectangular interior cross section . it is to be noted that all seals mentioned herein are continuous and without gaps through which water could transfer from one fluid passage to another or to atmosphere . all of the fluid - passing openings in this invention are preferably located in wall members rather than in the seams . of course , it is to be understood , variations of the present method as well as entirely different methods for producing the hose are contemplated . for example , any of the well - known methods for producing multichamber irrigation hoses by extrusion may be employed to produce the hose of the present invention . when hoses run downhill , there is a tendency for a slight incremental pressure increase in the second fluid passage 14 along the decrease in elevation . the actual increase in psi might be the same from this cause ( as with prior art hoses ) but the percentage of increase would be less due to the higher established pressure in the second fluid passage . by way of example , a two channel hose , such as that disclosed in aforementioned u . s . pat . no . re . 28 , 095 , operates with 0 . 5 psi as a typical outer chamber pressure . a 0 . 3 psi increase in the outer chamber due to decrease in elevation would be a 60 % increase in psi due to slope . in the present invention , with a typical 1 . 5 psi in the second fluid passage , a 0 . 3 psi increase would amount to only a 20 % increase in psi due to slope . the flow emission of the hose of the present invention increases at a rate approximately 50 % of any increase in the pressure at the inlet . this compares with prior hoses that rely upon the long path emitter principal ( a small emitter channel which has flow restriction similar to a tube ) which has flow rate change of approximately 100 % of the pressure change . this means that a long length of hose produced in accordance with the present invention would have a flow at the closed end more nearly equal to the flow rate at the inlet end than would a hose of equivalent flow rate using the long flow path emitter principal entirely . it is understood that a larger number of fluid - passing openings of a smaller size may be substituted for the first and second fluid - passing openings 32 and 34 ( as shown in phantom in fig1 ) as long as the total area of fluid - passing opening ratios ( herein described ) are maintained . an example would be substituting two or more first fluid - passing openings 32 &# 39 ; of smaller diameter for each first fluid - passing opening 32 mentioned in the preferred embodiment , keeping the same total area of opening ratios . these substitute smaller fluid - passing openings 32 &# 39 ; could be spaced at intervals with several close to each other , or spaced evenly throughout the length of wall member 18 . these more numerous , but smaller , first fluid - passing openings provide an advantage under some water supply conditions by acting as a filter to prevent foreign particles from entering the second fluid passage 14 . such foreign particles would then be flushed by opening the normally closed - off end of the first fluid passage 12 and allowing water to run a few minutes . with reference to fig6 through 8 , another embodiment is shown , where like reference numerals denote like elements , and only the differences will be described . the basic difference between the first and second embodiments is in the arrangement of the discharge fluid - passing openings 36 . in the second embodiment , as shown in fig6 the discharge fluid - passing openings 36 are substantially larger than the second fluid - passing openings 34 and are located slightly offset , preferably closely positioned on either side approximately a half an inch from the second fluid - passing openings . this other embodiment has the advantage of the no - squirt feature , due to the ratio of the total area of the discharge fluid - passing openings to the total area of the second fluid - passing openings being large enough so that the pressure is reduced within the third fluid passage 36 to within the range of approximately a 1 &# 34 ; or less head of water in case of a 0 . 062 &# 34 ; discharge fluid - passing opening , and approximately a 4 &# 34 ; or less head of water if 0 . 018 &# 34 ; discharge fluid - passing openings are used . however , this other embodiment does not substantially increase the pressure in the second fluid passage nor does it provide the advantage of the higher pressure second fluid passage herein referred to . while descriptions herein have generally referred to water and fluid passages , it is understood the same hose can be used for chemical solutions such as insecticides , fungicides , fertilizers and also compressed air for soil aeration . since there is a wide variety of conditions encountered in the field , it is understood that the preferred embodiment is only one of many combinations of ratios and sizes of first fluid - passing openings , spacing of second fluid - passing openings , spacing of discharge fluid - passing openings , cross section of the third fluid passages , and pressures introduced into the first fluid passage , which fall within the scope and function of this invention . for example , it is contemplated that two or more discharge fluid - passing openings ( 36 &# 39 ; in phantom in fig4 ), spaced close together , may be substituted for each discharge fluid - passing opening 36 , their total area being sufficient to pass the desired flow without creating substantial pressure loss therethrough . likewise , it is contemplated that one or more slits made close together longitudinally in the wall 42 may be made for each discharge fluid - passing opening 36 . such slits may be on a common line longitudinally of the hose or paralel side by side . the foregoing is considered as illustrative only of the principals of the invention . further , since numerous modifications and changes will readily occur to those skilled in the art , it is not desired to limit the invention to the exact construction and operation shown and described , and accordingly all suitable modifications and equivalents may be resorted to , falling within the scope of the invention as claimed .
an elongated water distributing hose capable of effectively watering large areas with readily available water pressures and in a matter whereby an essential uniform watering is achieved . this desired uniform watering results notwithstanding sloping ground conditions and the like . the pressure is substantially maintained throughout the length of the hose though a particular arrangement of first , second , and third fluid passages , which enable a maintaining of the relatively high pressure throughout the length of the hose and the reduction of this pressure directly at the point of the passing of the water from the high pressure first fluid passage through a series of first fluid - passing openings to the much smaller second fluid passage , and a further pressure reduction as the water passes within the third fluid passage between a series of second fluid - passing openings and a series of discharge fluid - passing openings . in this way , the hydraulic principle of flow of fluids passing through an orifice is combined with the hydraulic principle of flow of fluids moving through a slender tubular member made into one continuous hose .