Abstract:
The hose, which is particularly adapted for use with an electrically-driven vacuum cleaning apparatus, comprises a substantially air-tight, flexible tube which is pneumatically coupled between the vacuum pump and the suction head. The suction hose comprises one or more elongated strips which is or are helically wound into tubular form. In a pair of parallelly placed strips, the strip margin of the first strip is secured to an adjacent margin of the second strip at adjoining convolutions of the strips. Electrical conductors are carried by the strips within helically extending cavities formed at the edges or margins of each of the strips and are a portion of that means which electrically couples the cleaning brush to the electrical power supply.

Description:
BACKGROUND OF THE INVENTION 
     This is a continuation-in-part of copending application, Ser. No. 004,695, filed Jan. 19, 1979, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a flexible tube in combination with an energy-carrying conductor or conductors which is or are preferably, but not exclusively, adapted for use as a suction hose in combination with electrically-driven vacuum cleaning apparatus. 
     DESCRIPTION OF THE PRIOR ART 
     While the present invention has particular use as a suction hose in combination with vacuum cleaning equipment, such as a conventional tank or canister-type vacuum cleaner, it is to be understood that its particular application will be limited only to the end needs of the ultimate user. 
     Hoses of this type are well-known in the art, as represented in the patent literature. Illustrations are exemplified in the following United States patents: electrical conductors extending generally parallel to the axis of the hose, as shown in U.S. Pat. Nos. 3,965,526 and 4,064,355; alternative designs of electrical conductors extending along the axis or spirally wound, but not used as structural support, as in U.S. Pat. Nos. 3,277,231 and 3,715,454;  electrical conductors in single or parallel configuration extending in a spiral fashion along the hose and utilized additionally as a hose-reinforcing element, as in U.S. Pat. Nos. 2,890,264 and 3,917,499; and electrical conductors which may or may not act as reinforcing elements which are embedded or otherwise carried in convoluted strips which overlap in helical fashion to form the hose, as in U.S. Pat. Nos. 2,516,864; 2,695,631; and 3,273,600. While these hoses are presumed to work well for their intended purposes, they are illustrative of a very large number of designs that have been developed to overcome problems in the art. 
     Experience has indicated that the following problems exist in such prior art hoses. Wires which are used as structural supporting members in the hose, primarily to resist radial crushing thereof, generally are positioned in such a manner that they cause the hose to have undue wear, which considerably decreases the life span of the hose. When such support wires are also electrical conductors, e.g., see U.S. Pat. No. 3,917,499, one area of their insulation is held exposed by the unyielding support wire to the severest area of wear, cut, or puncture, thus opening electrically live conductors to the grasp of the human hand. Realizing such limitations, other hoses have been designed so that the wires are utilized solely for their current-carrying characteristics, and the hose is otherwise formed to obtain maximum support and wear resistance through other means. The result generally is a bulky profile, which lacks economy in the use of material. Even when these problems are overcome, manufacture of the hose is complicated in that the current-carrying conductors must be appropriately handled during formation of the hose or in other steps in its production. In addition, such production techniques may limit the number or type of conductors that are used. 
     A further limitation in prior art hose exists in rigid retention of the electric conductors in the hose. If a pin or other subject should puncture the hose adjacent the conductor, there is a large probability that the puncturing instrument will contact the conductor, because the conductor has no capability to be deflected and move within the hose. 
     SUMMARY OF THE INVENTION 
     The present invention avoids or overcomes these and other deficiencies, drawbacks or problems by providing for a simply manufactured hose having electromagnetic energy-carrying conductors therein. Briefly, the hose comprises a strip which is helically wound into a tubular form with one of the strip&#39;s margins secured to an adjacent margin at adjoining convolutions of the strips. At least one cavity is formed in one of the strip margins in which the electromagnetic energy-carrying conductor is carried. For a single strip, there may be double or triple conductors. For a plurality of strips extending helically in parallel, one conductor may be placed in each cavity. It is preferable that the wire be loosely held within the cavity; however, it is possible to extrude the profile with the wire therein. A preferred use of such a hose is in combination with vacuum cleaning apparatus. 
     It is, therefore, an object of the present invention to provide for a hose with energy-carrying conductors in which the conductors are not a primary contribution to the supporting structure of the hose. 
     Another object is to provide for maximum structural support of the hose profile commensurate with maximum flexibility thereof. 
     Another object is to provide for conductors which are designed solely for their energy-carrying characteristics without regard to the support of the structure so that the hose may be tailored to use of the best electrical conductors or other electromagnetic means carried by the hose. 
     Another object is to provide for a means by which the flow path of the electromagnetic current is separate from the flow path of fluid flowing through the hose. 
     Another object is to provide for protection of the conductors from abrasion and wear, as well as to increase the amount of insulation above the conductors. 
     Another object is to provide space in the hose to allow for rolling or sliding of the conductor to aid in avoiding puncture by pins and the like. 
     Another object is to provide for a multiple profile hose which permits the use of one or a multiple of conductors therein. 
     Another object is to provide for ease and efficiency of manufacture of such a hose. 
     Another object is to provide for such ease and economy of manufacture both in extruding the profile and in convoluting the hose. 
     Another object is the use of such a hose in combination with vacuum cleaning apparatus. 
     Other aims and objects, as well as a more complete understanding of the present invention, will appear from the following explanation of exemplary embodiments and the accompanying drawings thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of a cleaning apparatus equipped with the hose assembly of the present invention; 
     FIG. 2 is an enlarged plan view of the hose assembly depicted in FIG. 1; 
     FIG. 3 is a cross-sectional view of a portion of the hose depicted in FIG. 2 showing how convoluted strips are interengaged to form a hose wall section, as well as to show how electrical conductors are carried in specially made cavities therein; 
     FIG. 4 is a modification of the hose strip depicted in FIG. 3; 
     FIG. 5 illustrates the preferred machine and method for fabricating the hose depicted in FIGS. 2 and 3, with FIG. 5a being an enlargement of a part of the machine; 
     FIGS. 6 through 8 are cross-sectional views of steps in manufacturing the hose, taken along lines 6--6, 7--7, and 8--8, respectively, of FIG. 5; 
     FIG. 9 is a plan view of another embodiment of the hose assembly usable in the cleaning apparatus depicted in FIG. 1; 
     FIGS. 10-15 are cross-sectional views of portions of five embodiments of the hose illustrated in FIG. 9 showing how convoluted strips are interengaged to form hose wall sections with electrical conductors; and 
     FIG. 16 is a cross-sectional view of a portion of a hose similar to that depicted in FIG. 10 but applied to the hose of FIG. 3. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 depicts a preferred use of the present invention in which it comprises a component of a cleaning apparatus 10. As is conventional, cleaning apparatus 10 includes a vacuum pump housing or canister 12 communicating with a vacuum head 14 by means of a suction hose assembly 16. Canister 12 contains the vacuum pump with its drive motor, a vacuum chamber, a filter bag, controls and other components of a conventional vacuum cleaning device. The vacuum pump motor is connected to an electrical supply by a cord 18. Electrical wires from cord 18 extend into a conventional hose attachment with electrical socket 20, while a similarly conventional hose attachment with electrical socket 22 extends from vacuum head 14. 
     As shown in FIG. 2, hose assembly 16 includes a pair of mating hose attachments 24 which mechanically connect to hose attachments and sockets 20 and 22. Electrical pins 26 or the equivalent in hose attachment 24 respectively are coupled to the electrical sockets included within hose attachments 20 and 22. Because canister 12, vacuum head 14, and the various hose attachments and electrical sockets are conventional in the art, further description thereof will be dispensed with, it being recognized that vacuum head 14 includes an electric motor for driving one or more brushes, beater bars or similar moving devices which are intended to facilitate movement of dirt from the surface to be cleaned into the suction head. 
     Hose assembly 16 further comprises a hose 28 having electrical or electromagnetic energy-carrying conductors therein. The hose comprises one or more strips 30 which are helically wound so that one strip margin is secured to an adjacent strip margin at adjoining convolutions. 
     One such configuration is depicted in FIG. 3 which comprises a pair of strips 30a and 30b. Prior to convoluting of the strips into a hose, a strip 30a is secured to a strip 30b at their respective margins and, thereafter, the parallel strips are convoluted into the hose, as will hereinafter become better understood. The strips are preferably extruded to provide cavities 32a and 32b respectively at first strip margins 34a and 34b, and generally hook-shaped covers 36a and 36b respectively, defining the second strip margins of strips 30a and 30b. 
     All cavities are similarly formed and each comprises a generally U-shaped channel 40 having a base 42, a first side wall 44 extending from the base at the end of the strip edge, a second side wall 46 spaced from the first side wall and also extending from the base, and a top wall 48 hinged at 50 to first side wall 44. Hinge 50 generally comprises a necked-down portion of the strip which is formed during extrusion. As shown in FIG. 3, hinge 50 acts to facilitate bending of top wall 48 so that it will easily overlie and close channel 40 by coming into contact with second side wall 46. Both the bent and unbent configurations of top wall 48 are illustrated in FIG. 3. 
     Lying within respective cavities 32a and 32b are electrical conductors 52a and 52b. Bare wires may be placed within the cavities, if the strip material is of insulative material; however for double protection, wires 52a and 52b may have insulation material 54 thereon. Thus, any possible leakage of conductive fluid from the inside of hose 28 into cavity 40 will not result in a short circuit between wires or the carrying out of electric current to the human touch. In this respect, it is preferred that top wall 48 be bonded by a bonding agent 57 to second side wall 46, as well as to adjacent portions of hook-shaped covers 36a and 36b. The bonding material is preferably limited to the ends of walls 46 and 48 and the adjacent end leg portions 37 of covers 36a and 36b so that the hose will bend and flex much in the manner that is described in U.S. Pat. No. 3,255,780, whose principles of construction and flexibility are incorporated herein. Thus, those elements, for example of strip 30a in FIG. 3 identified by indicia 43a and 45a connecting base 42 with an intermediate leg portion 39, impart flexibility and support to hose assembly 16. Accordingly, elements 43a and 45a and leg portion 39 and their connecting hinge-like corners, including the corner between portions 37 and 39, may be termed flexible elements. Also, element 45a, portion 37 and walls 44 and 46 may be termed support elements in that they help to resist radially-exerted crushing forces on hose assembly 16. Equivalent elements appear in the embodiments of the remaining figures. Although not critical, any bonding material which may also adhere to intermediate leg portion 39 is not desired because it decreases flexibility of the hose. 
     It is further possible to utilize three or more strips, rather than those two which are depicted in FIG. 3, if it is necessary that there be more than two wires. For example, it may be necessary to utilize a third grounding wire as well as other wires which may be connected to an &#34;on-off&#34; switch. Therefore, it is to be understood that the concept of the present invention is not to be limited to use of a pair of strips but to one or more strips. 
     Furthermore, as shown in FIG. 4, a single strip 130 may be utilized in which a single large cavity 132 may incorporate a pair of wires 152 which, although shown as a pair of single wires, may be the conventional insulated double-wire configuration. Those double wires may be placed vertically, as shown, or horizontally and may include more than two conductors. In a like manner to that shown before, a bonding agent 156 secures together a top wall 148 and a second side wall 146, and the two walls to adjacent portions of a hook-shaped cover 136 in a manner similar to that discussed above with respect to FIG. 3. It is to be further understood, as a modification, that the single wire configuration of FIG. 3 may be combined with the double wire configuration of FIG. 4, utilizing a pair of parallelly extending strips. 
     If desired, wires 52a and 52b, and 152 may be extruded at the time strips 30 and 130 are formed. 
     The preferred method of forming the hose, such as shown in FIG. 3, is described with reference to FIGS. 5 through 8. This assembly is with reference to a pair of strips 58 and 60, each of which is formed by conventional extrusion operations. Strip 60 is fed between a pair of rollers 62 and 64 configured as shown in FIG. 6 to properly handle strip 60 as it passes therethrough. While passing through rollers 62 and 64, a wire 66 is also combined so that strip 60 with wire 66 therein approaches the next station at rollers 68 and 70. 
     At this point, strip 60 with its wire 66 therein is combined with strip 58. It is here that a first bonding agent 72 is applied to join a cavity margin of strip 60 with a hook-shaped cover of strip 58. The combination of strips 58 and 60 then proceeds to a further pair of rollers 74 and 76, which are configured similarly to rollers 68 and 70 and which permit insertion of a wire 78 therein. 
     From rollers 74 and 76, strips 58 and 60 in parallel formation are convoluted upon themselves as they pass around a mandrel 80, guided by its several rollers 82. The rollers have a general shape or configuration as depicted in FIG. 8, but with a pitch that would permit parallelly formed strips 60 and 58 to be helically wound into tubular form, with one strip margin secured to an adjacent margin at adjoining convolutions. In addition, a further bonding material 84 is inserted between the hook-shaped margin of strip 60 and the cavity margin of strip 58. 
     It is an important aspect in the method of forming the hose that, as hose strips 58 and 60 are wrapped or convoluted into the desired hose shape, top walls 48 will naturally bend into closure with second side walls 46. A deflector 86 with angled end 88 (see FIG. 5a) and/or the shape of the rollers start or urge bending of the top walls in the proper closing direction, as illustrated by the phantom position 48&#39; of the top wall. Such natural tendency of the top walls to bend occurs if hinge 50 is above the area center of gravity 90 of the strip. 
     While such a configuration of roller pairs 62 and 64, and 74 and 76, and mandrel-rollers 80 and 82 cooperate to form a hose configuration such as depicted in FIG. 3, it is obvious that other configurations of roller and mandrel-roller pairs are suitable for producing single strip hose configurations or hose configurations comprising three or more strips. It is to be understood, of course, that the pitch of the convolutions, for a given strip cross-sectional configuration, becomes flatter and less acutely angled to the axis of the hose. Since the number of strips used in parallel affects the flexibility of the hose, such considerations as number of strips and strip configurations should be taken into consideration when a hose of particular flexibility is desired. 
     A modified hose assembly 116 is shown in FIG. 9 having a rounded, rather than square appearance. It comprises a hose 128 having electrical or electromagnetic energy-carrying conductors therein. The hose comprises one or more strips 230, 330, 430, 530, 630, or 730 (see FIGS. 10-15) which are helically wound so that one strip margin is secured to an adjacent strip margin at adjoining convolutions. A similar strip 830 (FIG. 16) is squared which, therefore, will form the hose configuration shown in FIG. 2. 
     Several similar, but modified, configurations are depicted in FIGS. 10-15 which respectively comprise pairs of strips 230a and 230b, 330a and 330b, 430a and 430b, 530a and 530b, 630a and 630b, and 730a and 730b. Prior to convoluting of the strips into a hose, a strip 230a, 330a, etc., is secured to a strip 230b, etc., at their respective margins, and, thereafter, the parallel strips are convoluted into the hose, as previously described with respect to FIGS. 5-8. To avoid needless repetition, all references to numerals of the &#34;200&#34; series of FIG. 10 are understood to apply likewise to the &#34;300&#34; through &#34;800&#34; series of FIGS. 11-16. 
     The strips are preferably extruded to provide cavities 232a and 232b respectively at first strip margins 234a and 234b, and generally hook-shaped covers 236a and 236b defining second strip margins respectively of strips 230a and 230b. 
     All cavities are similarly formed and each comprises a generally U-shaped channel 240 having a base 242, a first side wall 244 extending from the base at the end of the strip edge, a second side wall 246 spaced from the first side wall and also extending from the base, and a top wall 248 hinged at 250 to first side wall 244. Hinge 250 generally comprises a necked-down portion of the strip which is formed during extrusion. As shown in FIG. 10 (as well as FIGS. 11-16) hinge 250 acts to facilitate bending of top wall 248 so that it will easily overlie and close channel 240 by coming into contact with second side wall 246. Both the bent and unbent configurations of top wall 248 are illustrated. 
     Especially where hook-shaped covers 236a and 236b are rounded as shown in FIGS. 10-15, pegs 249, 349, 449, 549&#39; and 549&#34;, 649, 749&#39; and 749&#34;, and 849 extend from one of hook-shaped covers or top walls or both, and towards and into contact with the opposing top or cover, to ensure that hook-shaped covers 236a and 236b, etc., are properly supported by and above wall 248, etc., and to maintain the desired external hose appearance. The particular position of the peg is not critical, and it further acts as a dam for containing bonding material 256, etc., as precisely as possible. The preferred location of the peg is illustrated in FIG. 10, to afford maximum flexibility to the hose. 
     The use of pegs not only keeps the wire chamber, formed by the U-shaped channel and the top wall, closed, but also is used to provide other important advantages. It or they reinforce the upper part of the hose crown defined by the hook-shaped covers, and it can keep the bonding material at a vertical edge. 
     Lying within the respective cavities 232a and 232b are electrical conductors 252a and 252b. Bare wires may be placed within the cavities, if the strip material is of insulative material; however for double protection, wires 252a and 252b may have insulation material 254 thereon. Thus, any possible leakage of conductive fluid from the inside of hose 228 into cavity 240 will not result in a short circuit between wires or the carrying out of electric current to the human touch. In this respect, it is preferred that top wall 248 be bonded by a bonding agent 256 to second side wall 246, as well as to adjacent portions of hook-shaped covers 236a and 236b. Depending upon the particular construction defined by the pegs, the bonding material is to a greater or lesser extent limited to the ends of walls 246 and 248 and the adjacent end leg portions 237 of covers 236a and 236b so that the hose will bend and flex much in the manner that is described in U.S. Pat. No. 3,255,780, whose principles of construction and flexibility are incorporated herein. 
     It is to be further understood that the specific designs of the channel or cavity of FIGS. 3, 4, and 10-16 are the preferred designs, and, if desired, it may not be necessary to utilize a top wall such as top wall 48, but to dispense with it. It also may not be necessary to retain one side wall 46, but use side wall 44 in combination with top wall 48, using additional bonding material to compensate for lack of the second side wall. Furthermore, other strip configurations, such as suggested in U.S. Pat. No. 3,255,780, may be utilized; see, particular, FIGS. 10 through 18 thereof with the electrical conductor being placed at or adjacent to the bonding locations of those configurations. As still another modification, the design depicted in copending U.S. patent application, Ser. No. 678,547, filed Apr. 20, 1976, may be used in lieu of the presently described design. 
     Although the invention has been described with reference to particular embodiments thereof, it should be realized that various changes and modifications may be made therein without department from the spirit and scope of the invention.