Abstract:
A multi-purpose garment comprising a central portion and first and second end portions, the portions being rhombic in shape. The first end portion tapers inwardly from the central portion, and the second end portion tapers outwardly from the central portion. A pair of tent pole sleeves and a pair of ventilation openings are provided at the juncture of the first end portion and the central portion. A pair of tent pole sleeves are provided at the juncture of the second end portion and the central portion. On the underside ofthe garment, a sleeve extends along the outer end of each end portion, each sleeve containing an elastomeric cord to selectively compress selected portions of the garment.

Description:
FIELD OF INVENTION 
     The present invention is in the field of a garment which can be used by outdoors persons as well as military personnel. More particularly it is a garment which provides protection against weather as a short coat, long coat or tent. 
     BACKGROUND OF THE INVENTION 
     In the past, outdoors persons who hiked, climbed, fished or hunted as well as military personnel required protective coverings which would keep them dry and relatively warm under conditions wherein their activities would require weather protection of the upper body or, in the event of rain, maximum body protection in addition to providing a sleeping shelter. In the past, such protection required carrying a poncho-like garment which unfortunately had great bulk and was not easily worn over a backpack. To provide a sleeping shelter required the carrying of an additional piece of equipment which basically had to be joined to like a piece of equipment. Even this arrangement will not provide necessary protection because of the open ends of the so constructed shelter. Neither the poncho-like garment nor the shelter half could provide subsidiary uses such as a hammock or a single shelter. Neither article could provide a sleeping bag. 
     These disadvantages were overcome by the U.S. Pat. No. 4,484,362. For the first time there became available a single article which could be arranged in different modes to provide an anorak (short coat) covering the upper body and a backpack; a cagoule (long coat) protecting the legs in addition to the body while wearing a backpack; and an enclosed tent for a single occupant but being capable of being joined to a like article to provide a closed shelter for two persons; a summer shelter for a single person with a netted opening; a closed protection for seated person as well as a hammock. As great an improvement as the article disclosed in U.S. Pat. No. 4,484,362 was, continued trials disclosed short comings while detracted from is universality. The sleeping accommodation modes required the presence of suitable vertical structure such as trees for the suspension of the end portions of the article. Additionally the multipurpose article of U.S. Pat. No. 4,484,362 was basically a rectangular sheet. Extensive experimental field trials disclosed that there was excessive material in both end portions which served no true purpose in the sleeping shelter and hammock uses. Furthermore, the ratio of width to length was restriction in the sleeping shelter mode as to provide a cocoon like environment which was uncomfortable to user. Also the width of the multipurpose garment of U.S. Pat. No. 4,484,362 was found to be somewhat restrictive in walking as well as in rainy weather directing the flow of water onto the legs and feet of the wearer. 
     SUMMARY 
     In the present improvement over the multipurpose garment disclosed in U.S. Pat. No. 4,484,362, the top and bottom portions of the garment have been taper reduced, the garment has been enlarged in width and length, sleeves have been provided to give the garment in the sleeping shelter mode an independently suspended form which has a water-tight integrity of approximately 3 inches above the surface upon which the sleeping mode has been erected. 
    
    
     BRIEF DESCRIPTION OF THE INVENTION 
     The present invention can be seen in the accompanying illustrator of the preferred 
     FIG. 1 is an top plan view of the present invention. 
     FIG. 2 is a schematic topside plan view of the present invention. 
     FIG. 3 is a schematic bottom side view of the present invention. 
     FIG. 4 is a pictorial view of the present invention. 
     FIG. 5 is a view of the present invention in the embodiment of a single occupant inclement weather shelter. 
     FIG. 6 is a perspective view of the present invention as a two occupant inclement weather shelter. 
     FIG. 7 is a perspective view of the present invention as a fair weather shelter. 
     FIG. 8 is an elevation view of the present invention as seen in FIGS. 5 and 6. 
     FIG. 9 is an elevation view of the present invention as seen FIG. 8. 
     FIG. 10 is a pictorial view of the present invention when used as a sitting shelter. 
     FIG. 11 is a pictorial view of the present invention when used to form a long outer coat with backpack protection. 
     FIG. 12 is a pictorial view of the present invention when used to form a short outer coat with backpack protection. 
     FIG. 13 is an enlarged view of the tent pole webbing pockets. 
     FIG. 14 is a perspective view of the V-notched terminal of the cords undecided as a part of the present invention. 
     FIG. 15 is a perspective view of the tent poles, stokes and grey lines included as a part of the invention. 
     FIG. 16 is a perspective view of a modification of the sheltering FIG. 5. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With general reference to the drawing figures, the present invention uses a material from the many available which has the characteristics ranging from water-impermeable/air-permeable to water and air impermeable. Within this range, there are many fabrics. An additional characteristic of a desirable material is that the material does not become rigid or stiff at sub-zero temperatures. This is particularly important in military application since a stiff material is creates unwanted noise as the wearer moves through underbrush and the like. Preferably the material will be moisture impermeable and soft. Polyeurathane coated synthetic fabrics are preferable. 
     Returning to the drawings, FIG. 1 shows the major components of the present invention before assembly. This exploded view was selected to display the shapes of the components of the invention which results in a multipurpose garment which has less unneeded and unused material and more correctly provides the variety of applications to the need of the user than the previously cited patent and application of the assignee. 
     Specifically, with reference FIG. 1, the present invention comprises a left body portion 60, a right body portion 70, lower left back body portion 10, a lower right back body portion 40, a lower left front body portion 90, a lower right front body portion 100 and a hood portion 80. 
     Since the components of the matching portions are identical in the interest of brevity, the principal portions are described with reference to one portion with identical opposite elements being identified by appropriate opposite reference numeral. The body portions 60 and 70 are generalized rhombic in shape, having lower front edges 64 and 74 from which extend outwardly extending edges 61, 62, 71 and 72. The terminus of edges 61, 62, 71, and 72 which are opposite edges 44 and 74 are edges 63 and 73 which are arcurate in contrast to straight edges 64 and 74. The arcurate edges 63 and 73 drape the present invention more closely over a backpack when the invention is used as a coat and provide a more compatible curvature of the garment when used as a tent. Tent pole sleeves 66 and 76 are provided to receive the tent poles provided with the present invention. Body portion 60 and 70 are provided with matching cut out edges 65 and 75 which when edges 62 and 72 are sewn together provide an opening into which the hood portion 80 is inserted after edges 83, 84, 85, 86, 89 and 90 are sewn together to provide a head opening circumscribed by edges 87 and 88. 
     Lower back portions 10 and 40 are rhombic in shape, edges 13 and 43 have an arcurate form having the same but opposing radius of curvature as edges 63 and 73 of body portions 60 and 70 to which they are joined by sewing and sealing. Portions 10 and 40 are provided with rhombic openings 18 and 48 adjacent edges 13 and 43 which provide ventilation when the present invention is in the tent mode. Openings 18 and 48 are covered by fiberglass mesh material 19 and 49. The mesh material 19 and 49 is held in place by rhombic frames 20 and 50 of the basic material which are sewn in place and sealed. Nylon loop strips 21 and 51 are sewn and sealed to encompass openings 18 and 48. Flaps 22 and 52 to close openings 18 and 48 respectively have circumferentually mounted nylon locking material 23 and 53 and are joined to portions 10 and 40 when edges 13 and 43, 63 and 73 and pole sleeves 66 and 76 are sewn together and sealed. End portions of edges 11 and 41 carry sleeves 15 and 45 as seen in FIG. 3 each of which contains an elastomeric 121 cord in FIG. 14, each end of each cord having an end tip 122 having a V-shaped slot 123 to catch and hold the a portion of the cord when the cord is used in the application of the invention. The sleeves 15 and 45 are formed by sealingly sewing a separate sleeve portion to the underside of respective back portions 10 and 40 along edges 11 and 41 and seaming them along interior spaced seams 16 and 46 and sealing these seams as seen in FIGS. 1 and 3. 
     Lower front portions 90 and 100 are rhombic in shape with parallel edges 93 and 94 and 103 and 104. Sleeves 95/105 seen in FIG. 3 are formed in the same manner as sleeves 15/45 with sealed interior seams 96 and 106, the joined sleeve containing an elastomeric cord 121 with end tip 122 as in FIG. 14. Portions 90 and 100 carry tent pole sleeves 97 and 107 which are held within the seams joining edges 93 and 103 which in turn are sealed. It is to be noted that edges 91, 92, 101 and 102 taper outwardly to edges 94 and 104. This outward taper results in edges 94 and 104 extending forwardly and outwardly of the body of the wearer when the present garment is worn in the great coat configuration in FIG. 11, particularly during rain thus directing the rain away from the lower legs and shoes of the wearer. The outward taper also provides increased stability when the present invention is used as a tent. 
     Referring now to FIGS. 2 and 3, it is to be understood that the arcurate form of edges 13, 63, 43 and 73 when sewn together and sealed do not permit clear planular view of the assembled portions of the present invention in as much as the arcurate edges when sewn together create a bunching up of the garment along those seams which cannot be clearly and understandably illustrated by drawings. Therefore it was decided to present the assembled portions of the garment as shown in these figures for simplicity and clarity in viewing the assembled garment. 
     As seen in FIGS. 1-3, end portions 11/41 and 94/104 carry a plurality of snaps 110 and 111 respectively. Edge portions 12, 61, 91, 102, 71 and 44 similarly carry a line of snaps 113 and 114 respectively. It will be noted that snaps 113 and 114 are spaced interiorly from their respective edges. As seen in FIG. 3, a continuous line of double acting zippers 112 is sealingly sewn along edges 12, 61, and 91 and spacedly and sealingly sewn adjacent to edges 44, 71 and 104 on the interior side of the present garment. The positioning of zipper 112 spaced from edges 44, 71 and 104 provides an over hanging flap to protect the joined zippers in a tent mode from rain. In accordance with the present invention the tent poles seen disassembled in FIG. 15 are inserted into the pole sleeves 66, 76, 77 and 107 as will be subsequently described. To achieve the desired arcurate form of the tents as seen in FIGS. 5 and 6 the ends of the assembled tent poles are inserted in respective tent pole pockets 115 while are attached to portions 60, 70, 90 and 100 adjacent the respectives ends of the respective tent pole sleeves 66, 76, 97 and 107. The tent pole pockets 115 comprises at least one layer of a web strap 116 secured at one end to its respective garment body portion by sealed stitching 117 as shown in FIG. 13. The other end of the strap 116 is folded over as shown and stitched at 118 to form a pocket 119 to receive the end of an assembled tent pole as will be described. 
     As best seen in FIG. 4 hood 80 is provided with a tab 88a attached to the rear upper surface of the hood and having a nylon loop patch 886 which can be engaged with a nylon hook patch 88c on the visor 88d of the hood to hold the hood in an open position. Additionally one side of hood sleeve 89 is provided with a tab 88e having a nylon loop patch 88f which can engage a nylon loop patch 88g to close hood about the face of the wearer to cover the nose and mouth of the wearer. 
     Again with reference to FIG. 2 when the garment portions 10, 40, 60, 70, 90 and 100 are sealingly sewn together, hood portion 80 is sewn and sealed along edges 85 and 86 and edges 81 and 83 are sewn and sealed into edges 65 and 75. Edges 88 and 87 are folded over to form a sleeve 89 (FIGS. 2 and 4) through which runs a hood cord 89a to selectively draw the hood around the head of the wearer or to close the hood opening completely in the tent configurations of FIGS. 5, 6 and 16. A slide 89b is provided to engage each end portion of cord 89 to restrain the hood opening in the desired position. 
     Referring to FIG. 3 and 14 it will seen that joined sleeves 15/45 and sleeves 95/105 terminate in an angled edged matching edges 12, 44, 91 and 102. Sleeves 15/45 and 95/105 are open at each end which provides access to the elastomeric cord 121 which extends through each sleeve and terminates in a flat plastic cord holder 122, each holder having a notch 123 therein which receives and holds portions of the respective cord when it is elongated. The device disclosed in U.S. Pat. No. 3,953,911 is preferred. 
     Referring back to FIG. 3 it will be seen that the extreme ends of sleeves 15/45 are provided with grommets 22 and 53 and the extreme ends of sleeves 95/105 are provided with grommets 97 and 108. The purpose and use of these grommets will be described with reference to FIGS. 5-9. Each sleeve is also provided with a grommet 24 and 109 adjacent seam 14/142 and seam 92/101 respectively. 
     The accessories for the present invention can be seen in FIGS. 7, 9 and 15. FIGS. 7 and 9 show the bug-proof netting 130 which is used in the fair weather shelter seen in those figures. As can be seen the netting is rhombic in shape and carries a doubleacting zipper 131 around its periphery. Zipper 131 mates with zipper 112 shown in FIG. 3. FIG. 15 shows the accessories used to form the inclement weather shelters seen in FIGS. 5, 6, and 16. They comprise 6 pole sections having threaded male portions on one end with mating female portions on the opposite end and 2 pole sections having only mating female portions on one end; 6 tent greylines of flexible woven, weather resistant thermoplastic material; and 4 tents stakes as shown, preferrably of rust resistant material and capable of being pounded into the ground. 
     The single occupancy shelter seen in FIG. 5 is formed as follows. Layout the garment with the inner side (FIG. 3) up. Fold edges 41, 71 and 164 over to edges 12, 61 and 91 and close the respective zippers. Snap edges 11/41 to edges 94/104 together. Pull end of hood cord 89 to completely close hood about opening 66/95 and securely tie the hood. Make up two tent poles each of 4 sections 125a and 125b. Beginning on the zippered side insert one pole through sleeve 97 and insert the extending pole end into adjacent pole pocket 115. Then arching the pole insert the opposite pole end into the adjacent pole pocket 115. Repeat these steps with the other pole. Insert the end of one line 125 in grommet 24 and secure the end of the line. Insert the end of another line 125c in grommet 53 and secure the line end. Repeat the procedure with grommets 107 and 108. Insert two stakes 125d at an angle of about 30 degrees with reference to end 94/104 and secure the free ends of the lines attached to grommets 109 and 108. Repeat this procedure at the opposite end making certain the shelter is taut and substantially wrinkle-free. 
     The two man shelter of FIG. 6 is formed by firstly closing off both hood openings as described for FIG. 5. One garment is placed on the ground with the outer or hood side down. The other garment is placed over the first with the hood side up. The zippers of both garments and the end snaps are joined together. Two tent poles are assembled from the ferrule sections 125a and one unferruled section 125b. One pole is inserted into sleeve 97/107. After passing through the sleeves one end of the pole is inserted into adjacent pole pocket 115 and the other end is then inserted into pole pocket 115 thus arching the pole. The same procedure is followed with the other tent pole and the garment is extended to its fullest length. One guy line 125c with its attached cabiclic 125e is inserted into grommet 22, another into grommet 53 and yet another into grommet 24. At the other end, a guy line 125c with associated cabiclic is inserted into grommet 97, another into grommet 108 and a third into grommet 109. The guy line attached to grommets 22, 53, 97 and 108 are then drawn out at angles of about 30 degrees from the respective ends of the so assembled garments and secured to stakes 125a. Guy lines attached to grommets 24 and 109 are drawn out perpendicular to the ends of the assembled garments and secured to stakes 125d. 
     The fair weather shelter of FIG. 7 is formed by again closing off the hood as described with reference to FIG. 5. Netting 130 is provided around its periphery with a double acting zipper 131 which is compatible with zipper 112. End portions 10 and 40 are snapped together with snaps 110 and 111. Two poles are formed with 3 ferruled sections 125a and one unferruled section 125b. One pole is inserted into the end of pole sleeve 107 nearest the zippered netting and garment juncture. The end of the pole exiting sleeve 107 is inserted into pole pocket 115. The other end of the pole is inserted into pole pocket 115. The same procedure is followed with reference to sleeve 76. One guy line 125c with its cabiclic 125e is inserted into grommet 22 and drawn out to be secured to a stake 125d. Another guy line 125c with its associated cabiclic 125e is inserted into grommet 97 and is attached to a vertical support as available. Additional guylines 125c are similarly secured to grommets 22 and 108 and secured as described with reference to grommets 53 and 108. Additional guy lines 125c with associated cabiclics 125e are inserted into grommets 24 and 109 are attached to a stake 125 and to a vertical support. 
     The sitting shelter shown in FIG. 10 is formed by zipping sides 41, 71, 104, 12, 61 and 91 together approximately half way. Holding the thus zippered edges in front, step into the garment, lift up the unzippered portions up to insert the head into the hood opening. Throw the remaining portion of the garment over the head to the back, snap edges 11, 41, 94 and 104 together, turn the garment so the zippered portions are in the back and raise the hood over the head, leaving the unzippered together portions free. 
     To form the long coat seen in FIG. 11, begin with the garment as formed in FIG. 10 but with the edges 11, 41, 94 and 104 unsnapped. The unzipped portions are raised to form sleeves with ends 11/41 hanging free. Cord 121 is drawn from one end of sleeve 15/41 and passed around the back of the wearer to approximately waist level. The other end of cord 121 is held and the cord 121 is elongated to encompass the waist and one end is inserted in groove 123 thus forming a belt. The garment is smoothed over the front by pressing the excess material around each side of the wearer to the rear to provide the excess needed to cover any pack worn on the back of the wearer. 
     To form the short coat seen in FIG. 12, the front edges 94 and 104 of the long coat are raised to approximately waist level. Cord 121 is then pulled from both ends of sleeve 95/105 and brought around the waist and inserted in one of grooves 123 as was done in forming the long coat. 
     The one man shelter seen in FIG. 16 is formed as described with reference to FIG. 5 and FIG. 8 with the exception that ends 11/41 and ends 94/104 are not guyed out to stakes 125d. Instead ends 11/41 and 94/104 are each gathered together as shown and cord 121 in the respective sleeves is used to secure the gathered ends as shown. The guy lines are attached to respective pole pockets 115 in lieu of the aforedescribed grommets. The guy lines are secured to stakes 125d as shown. The purpose of this modification of FIG. 5 is for use in desert areas to present entry of snakes, scorpions and the like through otherwise snapped together edges 11/41 and 94/104 because of the cool or cold night temperatures. An additional guy line 125c is secured to each gathered end and secured to a stake 125d to elongate the end portions as much as possible. 
     A bag is provided to carry the tent accessories. Alternatively, a pocket shown in phantom 160 in FIG. 2 may be provided. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     Other features, advantages and purposes of the invention will appear clearly from the following description of the invention in reference with the appended drawings in which: 
     FIG. 1 shows the best embodiment of the invention liquid pump incorporated in a circuit for delivering a liquid; 
     FIG. 2 shows in more detail the sensors with timer used in the embodiment of FIG. 1; and 
     FIG. 3 shows an enlarged view of same embodiment of an invention liquid pump with a vertical cross-section at the level of the pump cavity with minor modifications. 
    
    
     DETAILED DESCRIPTION 
     In reference with FIGS. 1 and 3, it is shown the best embodiment of an invention device for improving working of liquid pumps. This liquid pump is referenced with the general reerence number 1 and has a pump cavity 2 (FIG. 3) in which a movable member or flexible pump diaphragm 3 is displaceable in function of filling or emptying said pump cavity 2 with liquid 4 preferably stored in a liquid storage tank 6 (FIG. 1). This liquid storage tank 6 is preferably located at a level higher than the level of the pump so as to feed said liquid with the aid of gravity. A duct 8 is connecting the liquid storage tank 6 to the pump 1 via a non-return valve 10. 
     According to the invention, said device comprises sensing means referenced with a general reference number 12 for detecting the displacement of the movable diaphragm member 3 and actuating means 14 for actuating filling or emptying of said pump cavity 2 in function of the displacement of the movable member 3. 
     According to a preferred embodiment, said device further comprises providing an intermediary member 16 linked in displacement to said movable member 3 and indicating at an appropriate distance, namely here at the free end 18 thereof, the position of the movable element 3. Accordingly, said sensing means 12 are sensing the position of the intermediary member 16, namely here the position of the free end thereof 18. To this effect, the intermediary member is preferably constituted by a rod having one end 17 fixed to said movable element 3, in practice constituted by a membrane, whereas the free end thereof 18 is slidably located within an hollow tube 20 preferably transparent so as to be easily seen from any operator. The original position of the free end 18 of the rod constituting the intermediary member 16 is such that the extreme positions of the movable member 3 are within the hollow tube 20 so as to be clearly seen by any operator. 
     Further, the pump cavity 2 is divided in fact into a first chamber 2a and a second chamber 2b by said movable member 3. Said first chamber 2a is foreseen to be filled by said liquid as clearly understandable from FIGS. 1 and 3. Movable member 3 is displaceable between a first extreme position 3a for which said first chamber 2a is essentially filled with said liquid and a second extreme position 3b for which said first chamber 2a is essentially emptied of said liquid. 
     Detecting means 12 comprises a bottom sensor 22 for detecting one extreme position of the intermediary member 16, i.e. here the extreme position 3b for which the first chamber 2a is fully emptied; and a top sensor 24 for detecting another one extreme position of the intermediary member 16 and thus of the movable member, i.e. the extreme position 3a for which the first chamber 2a is fully filled. 
     Bottom and top sensors 22, 24 emit a signal to said actuating means 14 as shown by the presence of electrical conduits 26, 28. On electrical conduit 28, i.e. between the top sensor 24 and the actuating means 14, a timer 30 is preferably interposed to permit actuation of actuating means 14 only when a predetermined period of time of cycle has lapsed since it will be understood that when the top sensor 24 detects the presence of the free end 18 of the intermediary members 16, the first chamber 2a will be fully filled, after having been previously emptied. 
     Further, the pump 1 also comprises means 32 for delivering a fluid under pressure, preferably air, to said second chamber 2b of the pump 1 by a fluid feeding duct 33, said feeding duct 33 being provided with a valve 34 for putting this duct 33 in communication either with said fluid under pressure or with the atmosphere by a derivation 35 provided with an air filter 36. This valve is preferably an electrically controlled valve such as an electromagnetic valve, with an electromagnet 41. 
     Accordingly, when the sensor 22 or 24, which can be for instance a proximity sensing sensor, is sensing the presence at the proximity thereof of the free end 18 of the intermediary pump actuating rod member 16, said sensor emits a signal to actuating means 14 which can include an electric center for closing an electrical circuit from an electrical current source 38 to for instance electrical means actuating the valve 34. Accordingly, the electrical center, when present, constitutes in fact a power relay. FIGS. 2 and 3 show a direct actuation of the valve by the sensors and in this case the actuating means 14 essentially comprise the electromagnet 41. 
     According to another embodiment of the present invention, pump 1 is a spring assisted pump and therefore comprises a spring 50 which is in a non-stressed condition in the off position of the movable member 3. This spring 50 is under a compressed state in the 3a position of the movable member 3 and is under an extensed condition in the position 3b of the movable member 3. 
     The fluid under pressure, preferably compressed air, is fed to duct 33 either by the aid of a compressor (not shown) or with the aid of a bottle of compressed air. 
     Further, the pump is delivering liquid into an outlet duct 9 provided with a non-return valve 11 of the same type as the non-return valve 10 of duct 8 from the liquid storage tank 6. 
     The operation of pump 1 is as follows: 
     The position of the movable member 3 being at first for instance the extreme position 3b for which the first chamber 2a is fully emptied, the free end 18 of the intermediary member 16 is in close contact to bottom sensor 22. Bottom sensor 22 therefor sends a signal to actuating means 14 to close valve 34 with respect to the source of compressed air and to put it in communication with the atmosphere so as to release the pressure into second chamber 2b. 
     As a result, liquid is fed by gravity from liquid storage tank 6 by a natural opening of non-return valve 10 and is filling first compartment 2a until reaching the extreme position 3a for which the free end 18 of the intermediary member 16 is in close contact to top sensor 24. 
     At this top position, top sensor 24 sends a signal to actuating means 14 to close the valve with respect to the atmosphere and to open it, i.e. to put it in communication, with respect to the source of compressed air. 
     However, in the preferred embodiment of the presence of a timer 30, this last operation is only allowed when the predetermined period of time set on the timer has lapsed, so as to adapt the pump rate to a predetermined liquid rate. 
     Therefore, once this predetermined period of time has lapsed, the timer 30 delivers an electrical signal to the actuating means 14 and fluid under pressure is fed to the second chamber 2b, thereby beginning the emptying of first chamber 2a and simultaneously closing non-return valve 10 and opening non-return valve 11. 
     When the movable member 3 is again reaching the bottom extreme position 3b, bottom sensor 22 is actuated and a further sequence begins. 
     Further, the free end 18 of the intermediary member 16 being seeable from the outside by being displaceable within a transparent hollow tube 20, any operator can see the actual position of this free end 18 and therefore of the movable member 3 within the pump. Accordingly, the operator can determine the actual time needed to perform a full filling of the pump by gravity. This is very important when the liquid to be pumped is viscous or is changing of viscosity and of density in the time. 
     Of course, preferably, the level in the liquid storage tank 6 is maintained constant to have a constant liquid pressure for feeding the pump. 
     It can be understood that all the positive technical results previously set forth are achieved, as well as the invention process previously emphasized. 
     Of course, should the sensors 22, 24 be able to deliver an electric signal sufficient to directly actuate the electromagnet of valve 34, then it can be avoided the presence of a current source but usually, the presence of a current source is required or at least of a power relay. 
     Accordingly, a number of modifications of the invention are possible without departing from the scope of the invention.