Patent Publication Number: US-11384870-B2

Title: Tapered stress-relieved helically reinforced hose

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a division of Co-pending application Ser. No. 15/530,040 filed Nov. 22, 2016 which is a continuation of application Ser. No. 13/507,172 filed Jun. 11, 2012 now U.S. Pat. No. 9,505,164 issued Nov. 29, 2016 which is a continuation-in-part of application Ser. No. 12/799,263 filed Apr. 21, 2010 now U.S. Pat. No. 8,453,681. 
     REFERENCE TO PROVISIONAL APPLICATIONS 
     Application Ser. No. 13,507,172 referenced above claimed the benefit of the Oct. 12, 2011 filing date of application Ser. No. 61/627,425. 
     Application Ser. No. 12/799,263 referenced above claimed the benefit of the Dec. 30, 2009 filing date of application Ser. No. 61/335,023. 
    
    
     INCORPORATIONS BY REFERENCE 
     The disclosures and entire contents of all of the applications identified above are incorporated herein by reference. 
     BACKGROUND 
     The present invention relates to helically reinforced tubing and/or hose that has one or more characteristics that vary along at least a selected portion of the continuous length of the tubing or hose, including diametrical size, wall thickness, pitch, strength, flexibility, stiffness, helix size and weight, while one or more of these characteristics may remain substantially constant along the same or a different selected portion of the continuous length of the tubing or hose, as may be desired for use in specific applications. 
     Tubing and hose that has one or more characteristics (such as are mentioned above) that vary progressively along at least a selected portion of the length of the tubing or hose has many commercial, industrial and medical uses. 
     Commercially, for example, a length of tubing or hose that has at least a portion of its length that tapers in diameter can be used to improve air flow and reduce the accumulation of debris along the length of tubing or hose. 
     Industrially, for example, a length of tubing or hose that has at least a portion of its length that tapers in diameter can be used to eliminate the need for adapters and connectors between lengths of tubing or hose that need to be of different diameters for various purposes. 
     Medically, for example, a length of tubing or hose that has at least a portion of its length that tapers in diameter can be useful in providing breathing conduits used with sleep apnea equipment and other medical devices related to breathing. 
     SUMMARY 
     The present invention preferably makes use of tubing or hose forming techniques of the general type described in U.S. Pat. No. 3,910,808 issued Oct. 7, 1975, and U.S. Pat. No. 3,966,525 issued Jun. 29, 1976 to William L. Steward, but advances the technology significantly beyond what is disclosed or suggested in the referenced Steward patents, the disclosures of which are incorporated herein by reference, in their entirety. 
     As used in this document, the terms “tubing” and “hose” are deemed to be substantially equivalent, and are therefore used interchangeably. 
     The present invention also relates to discrete lengths of tubing or hose that have one or more characteristics that vary progressively along the lengths of tubing or hose, with at least a portion of each discrete length of tubing or hose being annealed while being axially compressed to render the portion more flexible, and while giving the portion a “memory” that causes the portion to tend to normally return to the length at which the portion was axially compressed while being annealed. 
     Characteristics that may vary along the discrete lengths of tubing or hose include diameter, wall thickness, pitch, strength, flexibility, stiffness, helix size and weight—while one or more of these characteristics may remain substantially constant along the same or different parts of the discrete lengths of the tubing or hose. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, and a fuller understanding of the invention may be had by referring to the description and claims, taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view showing front portions of an apparatus embodying features of the present invention that may carry out method features of the invention to produce helically reinforced flexible tubing or hose that embodies product features of the invention; 
         FIG. 2  is another perspective view showing rear portions of the apparatus of  FIG. 1 ; 
         FIG. 3  is an enlarged perspective view of selected components associated with the support and positioning of one of a plurality of spinning rods arranged in an array within the apparatus of  FIGS. 1 and 2 ; 
         FIG. 4  is an enlarged, schematic, sectional view showing how edge portions of a web of extruded thermoplastic material overlap during helically winding to form a continuous wall of tubing or hose reinforced by a helically wound bead or rib that is integrally continuously joined with the wall of the resulting tubing or hose; 
         FIG. 5  also is an enlarged schematic view illustrating how a tape-like band of extruded thermoplastic is wrapped at a wrapping station in the apparatus of  FIGS. 1 and 2  about a circular array of turning, rotating or spinning rods; 
         FIG. 6  is a side elevation&#39;s view of a length of tubing or hose that has a straight-walled or truncated conical taper that transitions from a relatively smaller D 1  diameter to a relatively larger D 2  diameter, and then has a straight-walled or truncated conical taper that transitions back from the D 2  diameter to the D 1  diameter, and is transversely cut or severed mid-way along spaced, constant diameter portions, regions or reaches that are of the D 1  and D 2  diameters; 
         FIG. 7  is a simplified side elevation&#39;s view showing a portion of the apparatus of  FIGS. 1 and 2  with rods that define a wrapping station set to form a tubing or hose portion, region or reach of relatively smaller diameter; 
         FIG. 8  is a simplified side elevation&#39;s view similar to  FIG. 7 , but showing rods that define a wrapping station set to form a tubing or hose portion, region or reach of relatively larger diameter; 
         FIG. 9  is a side elevation&#39;s view of a length of tubing or hose that includes a concavely curved or tapered portion, region or reach transition&#39;s between tubing or hose portions, regions or reaches of relatively smaller and relatively larger diameters; 
         FIG. 10  is a side elevation&#39;s view of a length of tubing or hose that includes a convexly curved taper transition&#39;s between hose portions, regions or reaches of relatively smaller and relatively larger diameters; 
         FIG. 11  is a side elevation&#39;s view of a length of tubing or hose that includes a concave portion, region or reach transition&#39;s between two tubing or hose portions, regions or reaches of equal and relatively large diameter; and, 
         FIG. 12  is a side elevation&#39;s view of a length of tubing or hose that includes a convex portion, region or reach transition&#39;s between two tubing or hose lengths of relatively equal and relatively small diameter. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , a tubing or hose manufacturing apparatus embodying features of the present invention is indicated generally by the numeral  100 . The apparatus  100  is used to continuously produce helically reinforced tubing or hose  102  at a wrapping station  103  that is shown in  FIG. 1 . As the tubing or hose  102  is formed at the wrapping station  103 , the newly formed tubing or hose  102  not only turns, spins or rotates about a central axis  101  but also moves along the central axis  101  (as indicated by an arrow  104 ) as the newly formed tubing or hose  102  departs from the wrapping station  103 . 
     Continuous formation of tubing or hose by winding a continuously extruded web of thermoplastic material about an array of a plurality of rods  110  that are individually concurrently turned, spun or rotated in unison in a same direction of rotation is in accord with a method and apparatus that are described in the referenced two above-referenced Steward patents. As is also described in the referenced Steward patents, the rods  110  about which tubing or hose  102  is formed are canted relative to the central axis  101 ; and, the rods  110  converge as they extend from left to right (in  FIGS. 1 and 2 ) toward the wrapping station  103 . 
     As is explained in the above-referenced Steward patents, the chanting of the rods  110  assists a continuously extruded web of thermoplastic material to wind in a helically manner about the rods  110 , with an edge region of each newly wrapping convolution of hot, extruded thermoplastic material slightly overlapping and promptly bonding to an edge region of an adjacent, previously wound convolution to create a continuous, contiguously extending tubing or hose wall, and with a continuous bead or rib of extruded thermoplastic material wound helically circumferentially externally around and continuously bonded to the tubing or hose wall to provide reinforcement. 
     The material from which the hose  102  is formed at the wrapping station  103  preferably is hot, freshly extruded thermoplastic, typically extruded from a nearby die  107  of a conventional intrusion apparatus (not shown), in a manner well known to those who are skilled in the art of intrusion. 
     Heated thermoplastic material extruded under pressure from the die  107  preferably includes a relatively flat, tape-like, continuous web  105  that is of substantially uniform thickness—except that integrally extruded with the web  105  may be a longitudinally extending reinforcing bead or rib  106 , as is shown in the referenced Steward patents, that is typically wire-like in character so as to provide reinforcement when wound around and bonded to a wall of tubing or hose  102 . A wide range of thermoplastic may form the extruded material that is helically wound at the wrapping station  103 , such as, but not limited to, PVC, TPU, PP, TPE or ABS material. 
     It should be understood that the freshly extruded web  105  and the longitudinally extending rib or wire-like bead  106  are hot and tacky when they arrive at the wrapping station  103 , and readily tend to adhere and bond promptly to each other as these materials are overlaid and helically wound or wrapped to form the tubing or hose  102 . A typical manner in which the web  105  and the rib or bead  106  are overlaid and helically wrapped to form the tubing or hose  102  at the wrapping station is depicted somewhat schematically in  FIG. 4 , and is also described and illustrated in the referenced Steward patents. 
     Referring to  FIG. 4 , it can be seen that only edge portions  98 ,  99  of the relatively flat, tape-like web  105  are overlaid and caused to immediately bond—and that the wall of the newly formed hose  102  produced by the helically wound web  105  is overlaid and caused to be helically reinforced by the rib or wire-like bead  106  which is wrapped or wound circumferentially around and bonded continuously and integrally to the periphery or perimeter of the wall of the newly formed hose  102 . 
     At the wrapping station  103 , the arrayed rods  110  do not turn as a group or as an array about the central axis  101 . Rather, each of the identical rods  110  is supported by a separate pair of spaced-apart spherical bearings that enable the rods  110  to individually turn, spin or rotate about their individual centerline. The movable mounting of the bearings that support the rods  110  also enable the rods  110  to be moved radially relative to the central axis  101 , as will be explained in greater detail shortly. 
     As the hot, tacky, tape-like web  105  and the wire-like bead  106  are caused to helically wrap about the array of the spinning rods  110 , the speed and direction of rotation at which the outer surfaces of the rods  110  spin or turn corresponds to the direction of extrusion of thermoplastic material toward the wrapping station  103 , and at least equals or exceeds the speed of the moving extrusion. Preferably, the surface speed of the turning rods  110  at least slightly pulls or stretches the extruded thermoplastic to narrow and relatively tightly wrap the extruded thermoplastic material circumferentially about the array of turning or spinning rods  110 . 
     Schematically depicted in  FIG. 5  is the manner in which the spinning rods  110  are positioned in a circular array  109  at the wrapping station  103 . Also shown is how the spinning rods  110  receive the tape-like band  105  and cause the band  105  to helically wrap circumferentially around the array  109  of spinning rods  110  and bond where edge portions of the web  105  of extruded material overlap to thereby form a continuous, uninterrupted tubular wall of the hose  102 . At the wrapping station  103 , each of the rods  110  is identically positioned and spaced from the central axis  101 . The rods  110  turn concurrently, in unison, in a same direction of rotation, as indicated by arrows  95 , giving the rods  110  a surface velocity that is adjusted to match or slightly exceed the velocity at which the web  105  is fed from the extrusion die  107  located at one side of the central axis  101  in a direction generally toward the wrapping station  103 . The extruded web  105  is wound or wrapped in the manner indicated by the arrows  96 . 
     In the example illustrated by  FIGS. 1, 2 and 5 , the relatively close positioning of the rods  110  causes distances between adjacent ones of the spinning rods  110  to be relatively small, enabling only four of the spinning rods  110  of relatively small diameter to be used to form tubing or hose  102  of relatively small diameter. If, however, tubing or hose  102  of significantly larger diameter (not shown) is to be formed utilizing the technique described above, a larger number of the spinning rods  110 , and/or spinning rods  110  of somewhat larger diameter, may be used, with adjacent ones of the rods  110  spaced equidistantly and identically positioned relative to the central axis  101 , so that the tubing or hose  102  being formed does not collapse as the tape-like band  105  and the rib or wire-like bead  106  are being wrapped about the array  109  of spinning rods  110  at the wrapping station  103 . 
     A smaller number of the spinning rods  110  and/or rods  110  of smaller size can be provided if tubing or hose  102  of a quite small diameter (not shown) is to be formed at the wrapping station  103 . A larger number of the spinning rods  110  may be utilized if tubing or hose of larger diameter is to be formed at the wrapping station  103 . 
     As those skilled in the art of extrusion will readily appreciate, the tape-like band of thermoplastic material  105  and the rib or wire-like bead  106  of extruded thermoplastic material may be extruded from entirely separate supplies (typically from separate extruders, not shown), which is particularly useful if it is desired that the materials of the tape-like web  105  and the wire-like bead  106  be formed from different thermoplastics. However, in the example depicted in the drawings, a common thermoplastic is used to form both of the materials  105 ,  106 , and the continuous lengths  105 ,  106  are therefore simultaneously extruded from a single conventional extruder (not shown) through the single die  107 . 
     By controlling the quantity and velocity of the output of molten thermoplastic from the extruder die  107 , a consistent continuous supply of thermoplastic material is preferably provided forming the tape-like band  105  and the wire-like bead  106 , thereby insuring that the tubing or hose  102  formed at the wrapping station  103  has a desirably uniform wall thickness with a desired type of helical reinforcement extending therearound and bonded thereto. 
     The apparatus  100  that supports and spins the rods  110  includes a motor  120  that powers a gearbox  130  that has an adequate number of output shafts  131  so that each output shaft  131  can spin, turn or rotate a different one of the rods  110  of the array  109 . A gearbox  130  having a larger number of output shafts  131  is used if more than four spinning rods  110  are to comprise the rod array  109 . Likewise, a gearbox  130  having a smaller number of output shafts  131  is used if less than four spinning rods  110  are to comprise the rod array  109 . 
     The output shafts  131  are each connected by a flexible linkage  132  with a rear end region of a different one of the four rods  110 , to cause the rods  110  to spin, while also permitting the spinning rods  110  to be movably positioned by identical rear and front slides  140 ,  150  (a typical one of which is indicated by the numeral  150  in  FIG. 3 ) that carry identical rear and front spherical bearings (a typical one of which is indicated by the numeral  154  in  FIG. 3 ) that journal rear and front portions of each of the rods  110 , respectively. 
     As has been explained, the spinning of the rods  110  helps to cause the freshly extruded thermoplastic material that is extruded toward the array  109  of rods  110  to wrap about the rod array  109  at the wrapping station  103 . By controlling speed of the motor  120  (and hence the spin speed of the rods  110 ), the production rate of the tubing or hose  102  is controlled to provide a resulting tubing or hose product  102  that exhibits desired characteristics. 
     Referring to  FIG. 2 , the rods  110  extend forwardly from where they connect with the linkages  132 , to extend through rear spherical bearings that are carried by a set of rear slides  140  which are movable in directions radially toward and away from the central axis  101  along radially extending rear trackways  141  that are defined by a rear housing member  142 . Referring to  FIG. 1 , the rods  110  extend still farther forwardly to where they extend through front spherical bearings  154  ( FIG. 3 ) that are carried by a set of front slides  150  ( FIGS. 1 and 3 ) which also are movable radially in directions toward and away from the central axis  101  along radial front trackways  151  that are defined by a front housing member  152 . 
     As can best be seen in  FIG. 2 , four rear servo motors  143  are provided on the rear housing member  142  to move the four rear slides  140  radially toward and away from the central axis  101  along the four rear trackways  141  that are defined by the rear housing member  142 . Each of the servo motors  143  moves a different one of the rear slides  140 . Likewise, as can best be seen in  FIG. 1 , four front servo motors  153  are carried by the front housing member  152  to individually radially move the front slides  150  along the four front trackways  151  that are defined by the front housing member  152 . 
     By concurrently operating the four rear motors  143  in unison, and by concurrently operating the four front motors  153  in unison, the rods  110  may be moved radially (i.e., they may be repositioned radially) while maintaining the slides  110  at equal distances from the central axis  101 . By adjusting the positions of the rear and front slides  140 ,  150  along the rear and front radially extending trackways defined by the rear and front housings  142 ,  152 , respectively, the portions of the spinning rods  110  about which the freshly extruded thermoplastic materials  105 ,  106  are wrapped at the wrapping station  103  can cause tubing or hose of smaller or larger diameter to be formed at the wrapping station. 
     Preferably, the rear and front slides  140 ,  150  are of identical configuration, as are the rear and front spherical bearings that are carried by the slides  140 ,  150 . Likewise, the rear and front motors  143 ,  153  are identical, as are the output shafts of the motors  143 ,  153  that connect with and cause movement of the rear and front slides  140 ,  150  along the rear and front radially extending trackways  141 ,  151 , respectively. 
     A typical one of the slides  150  is shown in  FIG. 3  carrying a typical spherical bearing  154 . A typical one of the motors  153  also is shown in  FIG. 3  as having an output shaft  155  that is threaded into an associated one of the slides  150 . Rotation of the output shaft  155  in one direction causes the slide  150  to move toward the central axis  101 . Rotation of the shaft  155  in the opposite direction causes the slide  150  to move in an opposite direction away from the central axis  101 . 
     As can be seen by comparing the positions of the rear and front motors  143 ,  153  in  FIGS. 1 and 2 , the rear and front trackways  141 ,  151  that are defined by the rear and front housings  142 ,  152 , respectively, are typically not aligned. Stated in another way, the rear trackways  141  along which each of the rear slides  140  move are, in essence, “canted” relative to the front trackways  151  along which each of the front slides  150  move. The extent to which these rear and front trackways  141 ,  151  are canted held out of alignment is determined by a servo motor  160  carried by the front housing member  152 , which causes the rear housing member  142  to turn about the central axis  101  (to a small and limited extent) relative to the front housing member  152  (which is fixed and therefor does not turn about the axis  101 ). 
     The motor  160  drives an output gear  161  that meshes with and drives a much larger gear  162  that rings and is connected to the rear housing member  142 . Rotation of the output gear  161  of the motor  160  causes the large gear  162  to turn slightly about the central axis  101 , thereby causing the four planes in which the rear trackways  141  extend to turn either relatively closer into alignment with, or relatively farther out of alignment with, the four planes in which the front trackways  151  extend. By controlling the extent to which the rear trackways  141  are canted relative to the front trackways  151 , the extent to which edge portions  98 ,  99  of the tape-like band  105  overlap (as shown somewhat schematically in  FIG. 4 ) is controlled. Stated in another way, the helical wrapping of the tape-like band  105  and the wire-like bead  106  is caused to take place, and its character is controlled by the servo motor  160  which causes the rods  110  to be canted relative to the center axis  101 . 
     A significant feature of the present invention resides in the realization that the needed canting of the rods  110  that define the wrapping station  103 —the rods  110  about which extruded thermoplastic material is wound—can be nicely controlled by simply relatively turning the front and rear housing members  152 ,  142  about the center axis  101 . Although the referenced Steward patents recognize the need for canting rods about which extruded thermoplastic is wound, the Steward patents in no way teach or suggest that the needed rod canting can be provided simply by relatively turning two housing members that support front and rear sets of bearings that journal the rods for rotation. 
     Nor do the referenced Steward patents teach or suggest that needed rod canting can be adjusted or modified by relatively turning two housing members about a central axis along which newly formed hose travels as it exits a wrapping station defined by the spinning rods, or that the pitch of newly formed hose can be changed by relatively turning front and rear housings that carry front and rear bearings that support front and rear portions of the array of spinning rods that define a wrapping station. 
     Referring to the example illustrated in  FIG. 6 , a hose length  102  that exhibits a desired straight or conical taper that transitions from a relatively smaller diameter D 1  at point A to a relatively larger diameter D 2  at point B can be formed by first setting the rods  110  as illustrated in  FIG. 7  to form the relatively smaller diameter D 1 , and then gradually and progressively moving the rods  110  until they assume the configuration depicted in  FIG. 8  to form the relatively larger diameter D 2  to provide a hose length such as is shown in  FIG. 6  as extending from points B to C. The rods  110  are then preferably moved gradually and progressively back to the configuration depicted in  FIG. 7  to form a reverse of the A to B taper, yielding a taper that extends from points C to D, followed by the production of a length of the relatively smaller diameter hose D 1  starting at point D. 
     When the resulting hose shown in  FIG. 6  is cut in the two indicated places mid-way along the lengths that exhibit D 1  and D 2  diameters, two identical hoses are provided, each of which includes one of the depicted conical tapers. This technique of forming a single length of hose that includes a back-to-back sequence of two desired tapers (from a first diameter to a second, and then from the second diameter back to the first diameter, with the two tapered half lengths of hose then being cut apart), can be used repeatedly, yielding an extremely efficient way to produce hoses that incorporate a desired type of single taper. 
     The production of hose lengths that incorporate other types of tapers can also be produced using the adjustable rods  110  to define a wrapping station  103  where hose  102  of a desired configuration is formed. By way of example,  FIG. 9  shows a hose length  102  that incorporates a concavely curved taper  201  that extends between points E and F, to transition between a relatively smaller diameter and a relatively larger diameter. In a similar vein,  FIG. 10  shows a hose length  102  that incorporates a convexly curved taper  202  that extends between points G and H, to transition between a relatively smaller diameter and a relatively larger diameter.  FIG. 11  shows how a concave reach of hose  203  can be provided to transition between two hose lengths of substantially equal diameter; and,  FIG. 12  shows how a convex reach of hose  204  can be provided to transition between two hose lengths of substantially equal diameter. 
     To control the apparatus  100 , a conventional servo motor controller (not shown) is preferably provided that not only regulates the speed at which the motor  120  turns the rods  110 , but also the variable settings of the servo motors  143 ,  153  and  160 , and the parameters of operation of an extruder that extrudes the thermoplastic materials  105 ,  106  emitted from the extrusion die  107  toward the rods  110  at the wrapping station  103 . To form a tapered hose such as is depicted in  FIG. 6 , the parameters needed to produce the relatively smaller diameter hose D 1  at the wrapping station  103  are locked into the controller, as well as the parameters needed to produce the relatively larger hose D 2 , together with such information as is needed to define the taper that transitions between the two diameters D 1  and D 2 , and such parameters as position the rods  110  to produce a hose length exhibiting a desired pitch. 
     The term “pitch,” as it is used in conjunction with the formation of helically wrapped tubing or hose, means the distance from a particular point on one helix or wrap, to the same particular point on an adjacent helix or wrap—for instance, the distance from the center of one helix or wrap to the center of an adjacent helix or wrap. If the rods  110  were not canted at all, material  105  from the extruder die  107  would wrap atop itself time and again instead of helically wrapping to form the hose  102 . A small amount of canting or angulation of the rods  110  will cause the resulting helically wrapped hose  102  to have a tight pitch of short length. A larger amount of canting or angulation of the rods  110  will produce a helically wrapped hose  102  having a wider pitch of longer length. 
     To form a helically wrapped tubing or hose  102  of a certain diameter that has a given pitch length will require a certain angulation or canting of the rods  110 . Because the spacing of the rods  110  from the central axis  101  (at the wrapping station  103 ) determines the diameter of the hose  102  that is being produced, the rods  110  are first positioned so that a hose  102  is produced that is found to have a desired diameter. 
     Once the apparatus  100  is producing hose  102  of a desired diameter, the angulation or canting of the rods  110  is adjusted (by using the motor  160  to turn the rear housing  142  relative to the front housing  152 ) to give a rod angulation or canting that provides the resulting hose  102  with a desired pitch length. 
     To form a taper that progressively increases or decreases the diameter of the hose  102  being produced, the rods  110  are progressively moved radially inwardly or radially outwardly to modify the diameter of the resulting hose  102  in a desired manner. However, if the pitch of the hose  102  being produced is to be maintained while a taper in diameter is progressively being formed, it is also necessary to progressively alter or adjust the angulation or canting of the rods  110 . This is because a longer amount of time and a longer length of extruded material  105  are needed to form each wrap that is of a progressively longer length as the diameter of the hose  102  being produced is being progressively increased—and because a shorter amount of time and a shorter length of extruded material  105  are needed to form wraps that are of progressively shorter length as the diameter of the hose  102  being produced is progressively diminished. 
     A smaller angulation or canting of the rods  110  is needed to provide a given pitch when forming a larger diameter of tubing or hose  102 ; and a larger angulation or canting of the rods  110  is needed in order to provide the same given pitch when forming a smaller diameter of tubing or hose  102 . When a taper is being formed that increases the diameter of the hose  102 , the angulation or canting of the rods  110  (that is being progressively adjusted by the motor  160 ) must decrease if the resulting hose  102  is to have a constant pitch; and, when a taper is being formed that diminishes the diameter of the resulting hose  102 , the angulation or canting of the rods  110  must increase if the resulting hose  102  is to have a constant pitch. 
     In the formation of some lengths of the hose  102 , it is desired that pitch length be progressively altered to either increase or decrease. The motor  160  can be progressively used to effect such progressive changes in hose pitch. One reason why a change of pitch may be desired is that a tighter or shorter pitch length can provide a thicker, stronger, stiffer, more fully reinforced hose  102  that can handle increased pressure or a vacuum of greater intensity. Another reason why a change of hose pitch may be desired is to progressively change one or a selection of characteristics such as hose thickness, hose strength, hose stiffness or hose flexibility, hose weight, and other such characteristics that may be progressively changed along the length of a hose  102  being produced by the apparatus  100 . For example, a relatively small hose diameter might be selected having characteristics of one type for one hose region, and another region of the same hose might be formed with a larger diameter and different characteristics. 
     Once the system settings have been “trimmed” by the operator to give the desired end product, a hose will be automatically produced in a continuous cycle first giving a hose (as shown in  FIG. 6  hereof) that exhibits a constant first relatively smaller diameter D 1  having tapered length transitioning from the relatively smaller diameter D 1  to the relatively larger diameter D 2 , and then a tapered length transitioning back from the relatively larger diameter D 2  to the relatively smaller diameter D 1 . 
     The tapers or changes in hose diameter that are made along particular hose lengths or reaches may be conical in nature, or may conform to other configurations that provide relatively smooth diameter changes. Lengths or reaches of hose that are of substantially constant diameter may also be provided, as a design for a particular hose application may dictate. Hoses of desired constant diameter, or of a desired tapering diameter that changes slowly or rapidly over long or short reaches or lengths can be created, to provide an essentially limitless combination of hose diameters and taper angles. 
     What is not shown by  FIGS. 6 and 9-12 , but will be readily apparent to those skilled in the art, is that substantially any of the tapered forms that are shown may be combined, as a hose designer may deem appropriate for a particular application. 
     The process of the present invention works well with substantially any traditional material from which thermoplastic hoses commonly are produced—examples being TPC-ET, flexible polypropylene, polyethylene, polyurethane and the like. In a dual extruder arrangement where the tape material used to form the body of a hose and the helical reinforcing material are separately extruded, the helix material would typically be a harder material relative to the material used to form the tape-like wall portion of the flexible hose being manufactured. 
     The flexible hose formed herewith can, for example, have a hose wall defined by a thin, narrow, elongate web formed from PVC, TPU, PP, TPE or ABS material, and can, for example, employ a helical reinforcing spiral that is formed from PVC, TPU, PP, TPE or ABS material. 
     Textiles can be substituted for the wall-forming tape-like material, and a coated or uncoated wire can be used to form the reinforcing helix of the hose being manufactured. Any color or additive can be added to the plastic to give custom properties or appearance. 
     As is well known in the art of hose production, a so-called “crush cuff” of substantially uniform diameter can be provided where newly produced hose lengths are to be severed, thus providing newly produced hose lengths with regions that are well suited to join or mate with existing fittings or rigid conduits, which can be held in place by means of friction or through the use of any of a wide variety of known hose clamps and other mechanical contrivances. A typical cuff such as can be provided on a length of hose produced using techniques of the present invention is indicated by the numerals  18   a  and  18   b  in FIG. 4 of U.S. Pat. No. 7,014,449 issued Mar. 21, 2006 to Mark Woelfel, the disclosure of which is incorporated herein by reference. The referenced Steward patents also show the positioning of a roller  44  near where extruded thermoplastic material is wound about a plurality of spinning rods—a roller  44  that can be used to periodically flatten a reinforcing bead or rib to periodically provide cuffs that have no upstanding reinforcing bead or rib, and that may therefore be joined easily with existing fittings and the like. 
     If desired, features of the present invention may be practiced by replacing the smooth rods  110  that spin (about which the tape-like material is wound to form the flexible wall of the hose at the wrapping station  103 ) with contoured shafts that create hose profiles that are designed to increase the stretch ratio of the resulting hose. 
     In accordance with the invention described in an earlier-filed application Ser. No. 12/799,263 filed Apr. 21, 2010 by Martin E. Forrester et al entitled FLEXIBLE, STRETCHABLE, CRUSH RESISTANT HOSE WELL SUITED FOR MEDICAL APPLICATIONS, and its predecessor applications, the disclosures of all of which are incorporated herein by reference, in their entireties), tubing or hose lengths, or portions, regions or reaches thereof that are produced in accordance herewith may be compressed and annealed to impart ultra-flexible reaches with stretch ratios that are increased. Such stress-relieved hose reaches are particularly desirable in medical applications where undesirably stiff hoses may cause breathing masks to leak or move out of place, or may cause connections between tubing or hoses or components of tubing or hose circuitry to disconnect. 
     Utilizing features of the present invention, hose can also be manufactured with multiple starts, where two or more helical beads are used along with a tape-like band that is wide enough to span the entire width of the desired profile plus the necessary extra width to bond the profile beneath or overlying the helix to create a smooth hose. Multiple starts also allow the hose to be manufactured more quickly as the hose progresses down the length of the spinning rods two or more pitches per hose revolution. Further, multiple starts also allows for different materials to be used in the helical portion for color coding, or to provide other unique physical properties. 
     In some embodiments of the invention, multiple start helices (not shown) can be utilized (i.e., by using plural, side-by-side, simultaneous extrusions of hot tape-like bands of thermoplastic that wrap side-by-side so that overlapping edge portions of adjacent tape-like bands bond to form a hose wall), thereby resulting in a production speed that is increased by a factor equal to the number of multiple starts per hose revolution. 
     In some embodiments of the invention, the rate at which the rods are spun, turned or rotated is adjusted so that the angular velocity of the outer surfaces of the rods is preferably maintained at not less than the velocity at which hot thermoplastic material is extruded toward the wrapping station. In accordance with other embodiments, the surface speed of the outer surfaces of the rods may be adjusted to achieve a desired stretching or “draw down” of the molten tape-like band and/or the wire-like bead of the hot, freshly extruded thermoplastic so as to cause the newly formed hose to exhibit desired dimensions such as a particular desired thickness, or to exhibit desired characteristics of strength as chains of molecules become suitably oriented during formation of the newly formed hose wall and its helical reinforcement. 
     The present invention preferably provides an electro-mechanical system that repositions the spinning rods as hose is formed, to thereby create tapered lengths or reaches of hose, or hose that has tapered lengths or reaches between substantially straight lengths or reaches of substantially constant diameter that typically may be of differing diameters. The process used can be continuous in nature, repeating at pre-determined intervals to create hose with one starting diameter and length, followed by a tapered section of desired length, followed by an ending diameter and length—whereafter the process is reversed to create substantially the same piece of hose that transitions from the ending diameter and length to the starting diameter and length, with cuttings being made at locations selected to give two exactly identical pieces of hose. In much the same manner, the a hose being manufactured can be severed at various pre-determined positions to create desired discrete hose lengths consisting of one or more straight or constant diameter sections with one or more tapered sections therebetween, as a particular hose design dictates. 
     Among features of the present invention (that are in no way taught or suggested by the prior art) is an arrangement for movably supporting the individual rods in bearings that not only permit the rods to turn, spin or rotate, but also permit the rods to be concurrently radially moved continuously and progressively during formation of at least a continuous portion, region or reach of a length of thermoplastic tubing or hose that is being formed at a wrapping station, so that at least the resulting portion, region or reach of tubing or hose changes substantially continuously and progressively in diametrical size—so the resulting portion, region or reach of tubing or hose tapers as may be desired, for example to provide an appearance that is of truncated conical shape, or a configuration that is characteristically concave, convex or bulbous in appearance, or changes in some other way from one diameter to a different diameter. 
     As those skilled in the art will readily appreciate, the methods or techniques described herein can be used to provide tubing or hose lengths that have portions, regions or reaches of constant diameter (by maintaining the positions held by the rods such as is described in the two referenced Steward patents), and that have portions, regions or reaches that progressively change in diametrical size (by progressively moving the rods so that their positions relative to an imaginary center axis about which newly formed hose moves away from a wrapping station). Causing the rotating, turning or spinning rods of the rod array to be spaced farther from the center axis will cause hose being produced to have a relatively larger diameter or size. Causing the rods of the array to be spaced closer to the center axis will cause the tubing or hose being produced to have a relatively smaller diameter or size. 
     The method just described can be used to continuously produce reaches or lengths of helically reinforced flexible tubing or hose that exhibit a plurality of differing diameters, with transitional portions, regions or reaches that smoothly connect the differing diameters by means of conical tapers or tapers that feature other relatively smooth, continuous and progressive, curved or perhaps even elliptical areas of transition. 
     The heated, freshly extruded tape-like and wire-like thermoplastic materials that are helically wrapped to form a helically reinforced flexible hose in accordance with some embodiments of the invention 1) may be concurrently extruded from a single extrusion apparatus using a single extrusion die as a unified band of thermoplastic, 2) may be co-extruded from a single extrusion die using two or more extruders to provide thermoplastic materials to form a hose comprised of multiple materials having different properties (such as different stiffness, fatigue resistance, chemical resistance, or other physical properties), or 3) may be simultaneously extruded from separate extruders through separate extrusion dies so that the wall and reinforcing helix of the resulting hose are comprised of different materials that preferably are caused to bond as they are laid together at and move away from the stationary array of spinning rods at a wrapping station. 
     In accordance with some embodiments of the invention, continuous, pre-extruded tapes, fabrics, wire-like beads and the like can be utilized if they are heated before being brought together and wrapped about an array of spinning rods as described above, with heat being provided by a conventional external heat source (not shown) such as hot air to render bondable the materials that form a continuous tubing or hose wall and a continuous reinforcing helix bonded continuously to the hose wall. In some embodiments, adhesives also may be used to create a bond between materials that are wrapped about an array of spinning rods such as is described above to create a desired tubing or hose profile that spins about an imaginary central axis as it moves away from a wrapping station (as do all hose embodiments formed at a wrapping station defined by an array of spinning rods in accordance herewith). 
     Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example, and that numerous changes in the details of construction and the combination and arrangement of parts and techniques may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed. It is intended to protect whatever features of patentable novelty that exist in the invention disclosed.