Abstract:
A hose construction adapted for efficiently conveying fluids while extended, but capable of neatly contracting to a fraction of its extended length for storage or transportation, while integrally incorporating lines for electrical requirements. Storage may be within an outer hose and may be triggered via closure of a valve within a nozzle so that negative pressure causes contraction of the folds of the hose. The contracted hose has a length that is a fraction of its normal extended length. The hose construction incorporates a wire reinforcing member which may bias the hose for self-extension and may also function as part of the electrical system. The electrical lines may comprise stranded copper wires to conduct power and/or serve as a remote activation circuit. The hose configuration may have a cover with external folds, which maximizes flow and provides a cushioning outer diameter to prevent damage to the hose.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to flexible hose construction, and more particularly to a multi-wire electrical stretch hose construction capable of self-extension upon removal of negative pressures. 
       BACKGROUND OF THE INVENTION 
       [0002]    Flexible hoses have been utilized in many different applications involving transporting gases, liquids, and even solids, which are often in the form of particulate matter. Although most hose applications involve pumping material under pressure from a first location to second location, flexible hoses are frequently utilized in conjunction with electrical motors that create suction or negative pressure to create a vacuum. 
         [0003]    Vacuum hoses have numerous applications, such as the intake vacuum to supply air into the manifold of a combustion engine, the pump and filter of a swimming pool&#39;s water cleaning system, industrial uses for materials processing or manufacturing as in the production of composite parts that are vacuum bagged and cured in an autoclave, or in scientific laboratories where a vacuum is necessary for experimentation. 
         [0004]    Perhaps the most common application for a vacuum hose is its use in conjunction with the ordinary household vacuum cleaner. The home vacuum cleaner may be the most common usage of flexible vacuum hoses or perhaps may simply be the first application that comes to mind, but such vacuum cleaner usage may also be found in many commercial areas. Industrial vacuums are common in building construction for clean up after cutting operations or for water removal, and vacuums are even commonly truck-mounted to provide large scale, mobile vacuum capabilities with wide-ranging possibilities including sewage removal from cesspools to removal of litter, leaves, or pine needles from a golf course fairway. 
         [0005]    In the home vacuum application, and particularly for industrial vacuum applications, the hose may need to be of substantial length during the cleaning operation to be practical or efficiently utilized. However, a substantial length of hose attached to a vacuum canister unit, or to another body which supports a vacuum motor, becomes cumbersome to handle and transport after vacuum operations have been completed. Moreover, during such operations when a portable vacuum unit merely needs to be relocated to another area requiring its use, the length of hose may be unwieldy and difficult to handle because of its bulk, and may hamper or degrade the overall efficiency of the cleaning operation. 
         [0006]    These considerations have led to the development of stretch hoses, which provide greater convenience in the transporting and maneuvering of vacuum cleaners and hoses. While a stretch hose may simply be a hose whose construction permits a user to apply a force, which may be minimal, to increase the nominal working length of the hose, self-extending hoses are biased to extend to a greater working length without any effort on the part of the user, other than perhaps releasing a restraining mechanism that retains the hose in the retracted condition. 
         [0007]    One example of a self-extending hose is shown by U.S. Pat. No. 6,948,527 to Ragner. Ragner discloses a hose design which has a biasing spring that exerts an extending force on the cover material, and through the use of a pressure control mechanism, can utilize suction to retract the hose against the spring biasing. Ragner suggests the possibility of incorporating conductors to supply electrical power to the end of the hose, but defers offering a solution or configuration for such conductors. 
         [0008]    But U.S. Pat. No. 5,555,915 to Kanao offers a hose design whose construction incorporates a steel reinforcing wire as well as a conductive wire that is obtained by intertwisting a large number of copper fine wires. Kanao suggests a configuration whereby the reinforcing wire and conductive wire are side-by-side, with the hose cover material draping across the wire-pair and having inward folds which permit expansion. Kanao suggests that its construction provides extension/contraction zones that can be extended in the direction of the hose axis by manually pulling the hose, and that its use will result in “little user fatigue.” Thus, the hose is not actually capable of self-extension. The invention discloses herein provides a hose capable of self-extending while incorporating multiple wires capable of providing necessary electrical connections at the user&#39;s end of the hose. 
       SUMMARY OF THE INVENTION 
       [0009]    The self-extending flexible hose of this invention has many specialty applications, one of which may be for the storable hose arrangement of a vacuum cleaning system. In such a system, which will be described merely to exemplify the utility of this hose construction, the self-extending hose may be of a generous length so as to permit the user a large amount of freedom to maneuver while conducting cleaning operations. Such a long length of hose, while useful during vacuum operations would necessarily become cumbersome and bulky after operations ceased, when it must be either stored or transported to another work location. 
         [0010]    The self-extending hose of this invention not only permits retraction and subsequent extension, because of its construction, but it also integrally incorporates electrically conductive lines, which may provide electrical service to the user end of the vacuum system. The electrical service may be necessary to power ancillary functions related to the suction transmitted by the hose. Some common ancillary functions may arise from inclusion of a power head attached to the end of the hose, where the power head may have an independent motor to drive a beater bar or a brush roller. The electric lines may also be used to simply power a light. 
         [0011]    To create a storable hose arrangement, the self-extending hose of this invention is designed so as to be biased to its normal length when not otherwise restrained. However, the biasing may not be excessive, as this particular application utilizes vacuum pressure, once flow into the end of the vacuum hose has been blocked, preferably by a flow control valve, to retract the self-extending hose into a more manageable length. In this application, a secondary outer hose or constraining hose is included so as to be generally concentric to the self-extending hose, while only being a fraction of its length. The constraining hose may be in the range of about ten percent to about seventy percent of the length of the self-extending hose, but typically is roughly thirty percent of the length of the self-extending hose. Once the user has completed a vacuum operation in an area, and seeks to move to a new location or to cease operations completely, the user, while the negative vacuum pressure is still present within the self-extending hose, may close the valve so that the negative pressure creates a force which causes retraction of the self-extending hose at its folds. Retraction of the hose may be completed once a feature of the hose&#39;s nozzle co-acts with a cuff on the constraining hose to mechanically restrain the self-extending hose, after which vacuum pressure may be terminated. 
         [0012]    The construction of the hose disclosed herein is capable of neat retraction into the outer constraining hose, while incorporating multiple conducting wires to supply the electrical demands at the user end of the self-extending hose. This construction comprises a wire reinforcing member, preferably a steel wire, which is wound through a series of turns to preferably produce a helical shape not unlike that of a compression spring. The turns of the reinforcing member, as well as the interstitial space between the turns, receives a series of plies of thermoplastic material to create a flexible cover. The plies are formed so as to have an outward fold between the turns while the self-extending hose is in the unrestrained condition. The outward folding maximizes the inner diameter of the hose for a given construction, and accommodates the retraction of the self-extending hose. 
         [0013]    Disposed in the plies of thermoplastic material so as not to inhibit the retraction capability of the self-extending hose, may be the plurality of conducting lines in the form of stranded copper wire. Each of the stranded copper wires may be similarly formed into a series of helical turns so as to be located between the fold and the wire reinforcing member, but in close proximity to and only on one side of the wire reinforcing member. This positioning of the stranded copper wire in proximity to the wire reinforcing member and to the fold permits retraction of the self-extending hose at the folds, with resistance principally due to the wire reinforcing member. The wire reinforcing member may thus be designed so as to possess a spring rate which may bias the hose to its normal extended position once the valve has been opened, but a rate that is not so great as to prevent the system&#39;s vacuum pressure from overcoming the biasing to retract the self-extending hose into the constraining hose, with closure of the flow control valve. The plurality of wires may comprise two copper wires which conduct line voltage, a third wire which can serve as a second lead for a remote unit activation circuit, and a fourth wire reinforcing member which serves as the first lead. 
       OBJECTS OF THE INVENTION 
       [0014]    It is an object of this invention to provide a hose which is capable of transmitting suction 
         [0000]    loads from one end to another end. 
         [0015]    It is further object of this invention to provide a hose which may be flexibly utilized to transmit fluids. 
         [0016]    It is another object of this invention to provide a construction for a hose that is light weight. 
         [0017]    It is another object of this invention to provide a hose that is capable of contracting into a more compact form when not in use. 
         [0018]    It is another object of this invention to provide a hose which contracts when vacuum pressure is utilized to overcome biasing of a reinforcing member. 
         [0019]    It is another object of this invention to provide a hose capable of self-extension from a compact form once a restraining force is released. 
         [0020]    It is another object of this invention to provide a wire reinforcing member which serves as an electrical lead. 
         [0021]    It is another object of this invention to incorporate conducting wires into a self-extending hose. 
         [0022]    It is another object of this invention to provide a self-extending hose whose construction provides for outward folding of the cover material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a side view of the flexible hose of this invention shown in the extended condition, and is being utilized in conjunction with a negative pressure source, an outer constraining hose, and a nozzle with a flow control valve. 
           [0024]      FIG. 2  is the side view of the flexible hose and arrangement of  FIG. 1 , but where the valve had been closed to permit vacuum pressure to retract the self-extending hose to be within the confines of the outer constraining hose. 
           [0025]      FIG. 3  is an enlarged view of a section of the self-extending hose of this invention. 
           [0026]      FIG. 4  is an enlarged view of a section of the self-extending hose of this invention in a compressed form with the wire reinforcing member and conducting wires exposed. 
           [0027]      FIG. 5  is a cross-section showing build-up, on a mandrel, of the wire reinforcing member, the conductive wires, and plies constituting the flexible hose cover. 
           [0028]      FIG. 6  is a view of the flexible hose of this invention shown in its normal or extended condition. 
           [0029]      FIG. 7  is a cross sectional view of the flexible hose of  FIG. 6   
           [0030]      FIG. 8  is the flexible hose of the invention shown in a compressed or retracted condition. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0031]    A section of a self-extending hose  10  according to the invention is shown in  FIG. 1  as it is incorporated into a vacuum system. The particular vacuum system of  FIG. 1  in which the hose  10  is incorporated does not in any way limit usage of the hose of this invention, and is merely meant to provide one example of its possible use. 
         [0032]    In the vacuum system of  FIG. 1 , a first end  11  of the self extending hose  10  is connected to a source of negative pressure (not shown), while the other end is connected to a nozzle assembly  14 . The self-extending hose  10  is generally surrounded, in this exemplary embodiment, by a constraining hose  21 , which has a slightly larger diameter. The constraining hose  21  terminates in a cuff  22  that has a flared end  23 . The self-extending hose  10  may normally extend a substantial distance beyond the cuff  22  of constraining hose  21 . The constraining hose  21  may generally be flexible, but is preferably not a stretch hose. 
         [0033]    The nozzle assembly  14  may have a cylindrical casing  15  with a first end  19  that is open, and a second end  20  which may have a fitting in the form of a lip  18 . Although first end  19  is shown in  FIG. 1  with a simple cylindrical opening, it may also terminate in a vacuum head containing beater bars or a brush roller that is driven by a separate motor. The vacuum head of an alternative embodiment may also incorporate a light. The electrical requirements of these elements may be supplied by an external electrical cord that may be attached to the hose, but in the example shown which incorporates this invention, as is described in later paragraphs, the electrical requirements may be supplied by conducting wire that is integrally incorporated into the self-extending hose  10 . 
         [0034]    Protruding inward and then extending generally concentric to the cylindrical casing  15  at the second end  20  of nozzle assembly  14  may be a fitting or connector  17 . The connector  17  is of a diameter and configuration to permit mounting of the second end  12  of self-extending electrical hose  10 . The hose  10  may be fixed to the connector using a conventional clamp or other means commonly used in the art. With second end  12  of hose  10  attached to the connector  17  of nozzle assembly  14 , negative pressure generated at the source (not shown) is transmitted through self extending electrical hose  10  and through the nozzle assembly  10  to its open end  19 . The open end  19  of the nozzle assembly  14  may thus be utilized as needed in the desired vacuum operation, as the negative pressures would induce fluid flow, in this case air, to create suction forces that may draw particulate matter or other solids into the nozzle assembly  14  and through the hose  10 . 
         [0035]    Interposed between the open end  19  of nozzle assembly  14  and the nozzle&#39;s connector  17 , may be a flow control valve  16 . Flow control valve  16  may be incorporated to restrict or limit the intake of fluid entering the hose  10 . Additionally, flow control valve  16  may contribute to the control and operation of self-extending electrical hose  10  as follows. 
         [0036]    As previously described, the self-extending electrical hose  10  may be of substantial length while in its normal, unrestrained condition. The length may be chosen so as to provide the user with a very generous freedom of movement to enable efficient vacuum operations. However, this substantial length, while extremely practical and productivity enhancing during vacuum operations, may conversely be impractical afterwards, as such a lengthy hose would need to be gathered and possibly coiled to facilitate its storage or movement to another area requiring vacuum operations. It should be apparent that the longer the hose length that is utilized, the greater the bulk that requires handling both before and after vacuum operations, which requires a correspondingly greater amount of time and effort. The self-extending electrical hose  10  disclosed herein alleviates the tradeoff of utilizing longer hose lengths, while providing increased functionality in other respects. 
         [0037]    As previously stated, the self-extending electrical hose  10  may be disposed within outer constraining hose  21 , which may be utilized for retraction and storage of the self-extending electrical hose  10 . With the vacuum arrangement of  FIG. 1 , which includes a flow control valve  16 , the user, upon completing vacuum operations, may command the flow control valve using a switch that is common in the art, to not just simply restrict air flow, but rather to completely block the flow while negative pressures are maintained in the hose  10 . With the airflow blocked, the negative pressure in the hose, while it would not produce any noticeable affect on a rigid hose or pipe, would conversely have the effect of collapsing the self-extending electrical hose  10  at its folds. The hose  10  of this invention is particularly configured to include electrical wiring while still accommodating such hose contraction at its folds. 
         [0038]    The negative pressure would need to be maintained until the hose  10  had contracted sufficiently so as to draw the lip  18  of the nozzle assembly  14  within the flared portion  23  of cuff  22  of the constraining hose  21 . The flared portion  23  of cuff  22  would contain complementary features to catch and hold the lip  18  of the nozzle assembly  14 , and thus allow the self-extending hose  10  to be neatly gathered and held within outer constraining hose  21 , as shown in  FIG. 2 . Outer constraining hose  21  would therefore need to be designed based on the diameter of the self-extending hose  10  and any increase in diameter created by any folds that might expand outwards during contraction. The self-extending hose  10  may be stored and retained within outer constraining hose  21  by way of the mechanical connection between the lip  18  of the nozzle assembly  14  and the cuff  22  of the constraining hose  21 , and upon release of that mechanical connection by the user, biasing which is integral to the self-extending hose  10 , permits hose  10  to return to it normal unrestrained length. Outer constraining hose  21  may itself be of a length that is only a fraction of that utilized for self-extending hose  10 . The length of constraining hose  21  is preferably manufactured to be in the range of about ten percent to about seventy percent of the unconstrained length of self-extending hose  10 , and is more preferably between twenty percent and fifty percent of its length, and is most preferably in the range of about twenty-five percent to about forty percent of the length of self-extending hose  10 . 
         [0039]    The self-extending hose  10  is capable of the described contraction and self-extension while incorporating wiring to accommodate electrical requirements, by utilizing the construction which is shown schematically in  FIG. 5 , and is also shown in actual photos in  FIGS. 3 and 4 . 
         [0040]    Biasing of self-extending hose  10  is accomplished by the wire reinforcing member  30 , which is formed generally into a series of flexible turns about a longitudinal axis each having a spacing from an adjacent turn to create an interstitial area. The flexible turns of wire reinforcing member  30  are created during the manufacturing process by wrapping the wiring about a mandrel  25  as shown in  FIG. 5 . In order for the turns of the wire reinforcing member  30  to be flexible and possess the necessary spring rate to achieve proper biasing of the hose  10 , it may be formed using an elastic material. Although other materials are also suitable, a high strength steel has very desirable qualities and is often used. The wire reinforcing member  30  also will generally have a constant pitch over the length of the hose, and a generally constant radius of curvature, although those parameters could be varied for a particular hose application. Maintaining a generally constant pitch and curvature will lend the wire reinforcing member  30  to have a helical shape, which may be wound in either direction to produce a left-handed or a right-handed helix. 
         [0041]    The wire reinforcing member  30  may be a copper clad steel wire and may thus serve as a remote lead for remote unit activation or serve to both bias and support a flexible cover  34 . Flexible cover  34  may be formed of layers or plies  35  of thermoplastic material, which generally overlays the wire reinforcement member  30  and the interstitial area between the turns ( FIG. 5 ), and thus create a hose having an inner surface  36  for conveying the fluids, and an outer surface  37 . One or more ply layers  35  may be located on the inside surface  36  so as to completely surround wire reinforcing member  30  with thermoplastic material. The plies  35  may comprise a series of continuous plies that run the entire length of the cover  34 , or may comprise plies running for discrete portions of the length of the hose and have areas in which the plies overlap to form continuous surfaces  35  and  36  of cover  34 . The cover  34  material should naturally be impermeable to the fluids the hose  10  must convey. In the case of the vacuum system of  FIG. 1 , the cover  34  must serve simply as an air conduit. 
         [0042]    To facilitate the contraction of hose  10 , the cover  34  may be formed so as to have a fold composed of a first side  38  and a second side  39  such that the first side  38  may angle from the region of the wire reinforcing member away from the longitudinal axis of the helix. The first side  38  may reach an apex  40  and may be connected to second side  39  which angles back down toward the longitudinal axis of the helix and may terminate upon reaching a relatively short flattened cross-sectional area  41 . The flat area  41  of the cross-section may essentially create a valley between the second side  30  and the successive turn of the wire reinforcing member  30 . Having the folds of the cover  34  formed so as to be outward folded serves to maximize the inner diameter of the hose for a given construction. Also, the outwards folds of cover  34  may serve to provide a cushioning surface which may prevent damage or marring to the hose  10  or the surfaces the hose contacts, particularly as it is dragged along a surface during vacuum operations, and when it is drawn into the outer constraining hose  21  and may contact the constraining hose  21 . As the hose  10  is retracted into outer constraining hose  21  by closing the flow control valve  16 , while negative pressure maintained in the system, the first side  38  and second side  39  of the folds may generally move towards each other with the apex  40  expanding outward and away from the longitudinal axis. As the sides  38  and  39  of the fold expand outwards and generally towards each other during retraction, the inner surface  36  of cover  34  around the wire reinforcing member  30  may generally maintain a constant diameter. 
         [0043]    Electrical requirements of a particular vacuum system, possibly the separate motor for the beater bars or brush roller, or the light, may be facilitated by incorporation of a plurality of electrically conductive lines to conduct line voltage. In a preferred embodiment of the invention, shown in the schematic of  FIG. 5 , three conducting wires— 31 ,  32 , and  33 , are disposed between the thermoplastic plies  35  and are formed into a series flexible turns so as to be disposed adjacent to and generally parallel to the turns of wire-reinforcing member  30 . The flexible nature of the self-extending electrical hose  10 —in terms of contraction and expansion of its folds—is created by having the plurality of conductive lines  31 ,  32 , and  33 , being disposed to one side of the wire reinforcing member  30 . The conducting lines  31 ,  32 , and  33 , so as to possess adequate electrical conductivity, may be comprised of copper wire, which typically has gauges in the range of about 10 to about 30. The copper wire may also possess its own individual thermoplastic jacket to serve as insulation. 
         [0044]    The conducting lines  31 ,  32 , and  33  may also be in the form of stranded copper wire so as to not create a spring rate that is excessively high when combined with that of wire reinforcing member  30 . The spring rate of the self-extending hose  10  may be designed so as to permit the hose  10  to extend from the outer constraining hose  21  once the mechanical connection between cuff  22  and nozzle assembly  14  has been released, and upon removal of the negative pressure and the opening of the flow control valve  16 . The spring rate, while being large enough so as to accomplish biasing to the extended position, must not be excessive, as the negative vacuum pressure generated in the hose  10  must produce a retraction force large enough to overcome the biasing to permit retraction and coupling of the nozzle  14  to the cuff  22 . Design of the wire reinforcement member  30  of self-extending hose  10 , in regard to biasing capability, will also take into account the resistance due to the thickness of the thermoplastic ply layers used, and may be adjusted through the mean diameter of the helix, which may in fact need to be set based on the vacuum pressure expected and the desired fluid flow rate flow. The biasing capability may also be adjusted for a given hose through selection of an appropriate cross-sectional diameter of the wire, and the number of turns or coils per unit length of the wire reinforcing member  30 . 
         [0045]    While two of the stranded copper wires may be used for conducting line voltage, the third wire may be utilized as a second lead for remote unit activation. Furthermore, hose construction as shown by this invention is not limited to the three conducting wires  31 ,  32 , and  33  as shown in a preferred embodiment, and may include larger numbers of such wires. Two wires may be used in alternative embodiments, however the invention would only have remote activation functionality. Also, this construction for self-extending hose  10  permits incorporation, either along with or in place of the plurality of lines, of a fiber optic bundle for continuous signal conducting. 
         [0046]    Other modifications, substitutions, omissions and changes may be made in the design, size, materials used or proportions, operating conditions, assembly sequence, or arrangement or positioning of elements and members of the preferred embodiment without departing from the spirit of this invention as described in the following claims.