WO2025235281A1 - Dynamic airflow cushioning system for insulated wire in a twinner to reduce insulation crush - Google Patents

Abstract

First and second insulated conductors, which may include a dielectric tape located therebetween, pass from a first end to a second end of a bow of a twinner. The bow spins and helically twists the first and second insulated conductors. A fitting feeds an air flow stream into one of the first or second ends of the bow, so that the air travels through the bow. Alternatively, the bow can collect air through one or more slots as the bow spins. The air cushions the insulated conductors within the bow and reduces crushing of insulation layers of the insulated conductors due to centrifugal force. The air may optionally pass through plural through holes or nozzles in the bow and/or guides attached to the bow. The air may be at an ambient temperature, but may also be chilled to increase a compression modulus of the insulation layers.

Description

DYNAMIC AIRFLOW CUSHIONING SYSTEM FOR INSULATED WIRE IN A TWINNER TO REDUCE INSULATION CRUSH

BACKGROUND OF THE INVENTION

1. Field of the Invention

[001] The present invention relates to a twinner for twisting insulated conductors together to form a twisted pair. More particularly, the present invention relates to a cushioning system to prevent or minimize crushing of an insulation layer of an insulated conductor as it enters, exits and passes through a bow of the twinner.

2. Description of the Related Art

[002] Figure 1 is a perspective view of a twisted pair cable 1, in accordance with a first embodiment of the present invention. Figure 2A is a cross sectional view of the cable 1 taken along line II— II in Figure 1. A cable core includes first, second, third and fourth twisted pairs A, B, C and D, respectively. The cable 1 includes a jacket 11 surrounding the cable core. The jacket 11 may be formed of polyvinylchloride (PVC), low smoke zero halogen, polyethylene (PE), fluorinated ethylene propylene (FEP), polyvinylidene fluoride (PVDF), ethylene chlorotrifluoroethylene (ECTFE), or other foamed or solid materials common to the cabling art.

[003] The first twisted pair A includes a first insulated conductor 13 formed by a first insulating material surrounding a first conductor, and a second insulated conductor 15 formed by a second insulating material surrounding a second conductor, wherein the first and second insulated conductors 13 and 15 are twisted about each other to form the first twisted pair A. The dashed line "a" shows the outline of the space occupied by the first twisted pair A in the cable core.

[004] The second twisted pair B includes a third insulated conductor 17 formed by a third insulating material surrounding a third conductor, and a fourth insulated conductor 19 formed by a fourth insulating material surrounding a fourth conductor, wherein said third and fourth insulated conductors 17 and 19 are twisted about each other to form the second twisted pair B. The dashed line "b" shows the outline of the space occupied by the second twisted pair B in the cable core. [005] The third twisted pair C includes a fifth insulated conductor 21 formed by a fifth insulating material surrounding a fifth conductor, and a sixth insulated conductor 23 formed by a sixth insulating material surrounding a sixth conductor, wherein said fifth and sixth insulated conductors 21 and 23 are twisted about each other to form the third twisted pair C. The dashed line "c" shows the outline of the space occupied by the third twisted pair C in the cable core.

[006] The fourth twisted pair D includes a seventh insulated conductor 25 formed by a seventh insulating material surrounding a seventh conductor, and an eighth insulated conductor 27 formed by an eighth insulating material surrounding an eighth conductor, wherein said seventh and eighth insulated conductors 25 and 27 are twisted about each other to form the fourth twisted pair D. The dashed line "d" shows the outline of the space occupied by the fourth twisted pair D in the cable core.

[007] The twist lengths w, x, y and z of the first, second, third and fourth twisted pairs A, B, C and D may be set as listed in Table 1 of Figure 2B.

[008] For example, a first twist length w of the first twisted pair A may be shorter than a second twist length x of the second twisted pair B, and the second twist length x of the second twisted pair B may be shorter than a third twist length y of the third twisted pair C, and the third twist length y of the third twisted pair C may be shorter than a fourth twist length z of the fourth twisted pair Z. It should be noted that other twist lengths than those listed in Table 1 have been employed in cable 1 of the prior art, and may be employed while practicing the benefits of the present invention, which will be described in the Detailed Description of Embodiments of the Invention hereinafter. Further, it may be desired to purposefully modulate of the twisted pairs’ twist lengths and/or of a strand length of the cable core, as taught in the Applicant’s U.S. Patent 6,875,928, which is herein incorporated by reference.

[009] The first through eighth insulating materials employed by the first, second, third and fourth twisted pairs A, B, C and D may be formed of a flexible plastic material having flame retardant and smoke suppressing properties, such as a polymer or foamed polymer, common to the cabling art, like fluorinated ethylene propylene (FEP), polyethylene (PE) or polypropylene (PP). A radial thickness of the first through eighth insulating materials would typically be greater than seven mils, such as about ten mils or about eleven mils. The first through eighth conductors employed by the first, second, third and fourth twisted pairs A, B, C and D may be solid or stranded, and may be formed of a conductive metal or alloy, such as copper. In one embodiment, the first through eighth conductors are each a solid, copper wire of about twenty three gauge size.

[010] In one embodiment of the invention, the first and third twisted pairs A and C reside in approximately a first half of the cable 1, and the second and fourth twisted pairs B and D reside in approximately a second half of the cable 1. A region between the first and second halves of the cable 1 defines a middle region.

[011] A separator 3 is located within the middle region of the cable core and separates the first and third twisted pairs A and C from the second and fourth twisted pairs B and D. The separator 3 may be constructed as a substantially flat tape of a dielectric material. As seen in Figure 1, the cable core may be twisted in the direction of arrow 5 to form a core strand. In the illustrated embodiment, the direction 5 is opposite to the twist directions of the first, second, third and fourth twisted pairs A, B, C and D and may offer advantages as discussed in the Applicant’s U.S. Patent 6,770,819, which is incorporated herein by reference. However, this is not a necessary feature in the prior art. The core strand length may be approximately 2 inches, although other lengths may be employed.

[012] As best seen in Figure 2A, there are varying degrees of “crush” occurring in the first, second, third and fourth twisted pairs A, B, C and D. Crush occurs where the insulation layer of a fist insulated conductor contacts the insulation layer of a second insulated conductor. As shown, the crush is greatest in the first and second twisted pairs A and B, in comparison to the third and fourth twisted pairs C and D. It is believed that the crushing percentage is directly related to the twist length of the twisted pair, where tighter twisted pairs show more crushing of the insulation layers. Crushing a foamed insulation layer will increase the dielectric constant of the material in the crushed zone. This will slow down the signal speed in the conductor surrounded by the crushed insulation, which will affect a delay skew in the cable 1.

[013] As background, the four twisted pairs A, B, C and D in the cable 1 have different twist lengths w, x, y and z, so that internal crosstalk between the twisted pairs A, B, C and D can be reduced. See the discussion in Applicant’s US Patent 6,875,928, which is herein incorporated by reference. For a given length of cable, the twisted pair with a shorter twist length must travel a longer distance as compared to a twisted pair with a longer twist length. Therefore, the signals carried on the twisted pair with the longer twist length will arrive at the distal end of the cable before the signals carried on the twisted pair with the shorter twist length, which results in delay skew.

[014] To speed up the signals on the twisted pair with the shorter twist length (or to slow down the signals carried on the twisted pair with the longer twist length), the dielectric constant of the insulation layers surrounding the conductors can be modified. One way to accomplish this is to foam the insulation layers at different percentages, as taught in the Applicant’s US Patent 5,814,768, which is herein incorporated by reference. Another way is to introduce air channels into the insulation layers, such as employing the AirES® technology owned by the Applicant. See the Applicant’s US Patent 7,049,519, which is herein incorporated by reference. The differences in the dielectric constants of the insulation layers used on the different twisted pairs, whether accomplished by foaming or air channels, can be used to balance the delay skew between the twisted pairs. Also, a material type and/or radial thickness of insulation layers or conductor size in one twisted pair can be different relative to the insulated conductors of another twisted pairs to help balance a delay skew. Yet another way to balance delay skew is to vary a thickness or material type of a dielectric tape located between the insulated conductors of twisted pairs, as shown in Figures 3A and 3B, and as taught in the Applicant’s US Patents 11,424,052; 10,573,430; 9,978,480; 9,418,775 and 7,999,184, which are herein incorporated by reference.

[015] The Applicant has appreciated that the structural designs of the eight insulation layers to account for delay skew must also consider the crush level of the eight insulation layers. For example, different thicknesses in the material can be added to each insulation layer to account for the percentage of crush that will occur to that insulation layer during the twisting operation to form the twisted pair. Another possibility is to reduce the running speed of a twinner used to perform the twisting operation to form the twisted pairs, which seems to reduce the crushing of the insulation layers and allows the insulation layers to be thinner. However, running the twinner at a slower speed is counter to the consistent goal of speeding up production to lower overall costs.

[016] Chilling an insulation layer on an electrical conductor during the formation of an electrical cable is known in the prior art. For example, in a single pass cable manufacturing machine, wherein an insulation layer is extruded onto an electrical conductor and the insulated conductor is further assemble into a side-by-side relationship or a twisted relationship with another cable element, the insulated conductor is first passed through a chilling water bath prior to its placement adjacent the other cable element. The chilling water bath lowers the temperature of the recently extruded insulation layer, so as to avoid any sticking or adherence to the other adjacent cable element. The water in the water bath is constantly recirculated through a chiller, so as to remove the heat taken in by the water, as the water lowers the temperature of the recently extruded insulation layer.

[017] The twinner is a machine used to form a twisted pair. The twinner operates within a large enclosure or cabinet, e.g., approximately fourteen to twenty feet in width, seven to twelve feet in depth and seven to nine feet in height. The twinner is loaded with first and second full spools of insulated conductors, twists the two insulated conductors to form a twisted pair and loads the twisted pair onto a third spool for further processing on another machine outside of the twinner cabinet.

[018] Figure 3C is taken from Applicant’s US Patent 8,616,247, which is herein incorporated by reference. Figure 3C shows a twinner 100 in accordance with the prior art. A payoff station 110 includes reels 111 and 113 from which the first and second insulated conductors 13 and 15 are paid off to a guide plate 120. The payoff station 110 may have a housing 115. The payoff station 110 may include further mechanisms such as one or more line tensioners, mechanisms to apply a selected constant twist (e.g., a back twist) to the first and second insulated conductors 13 and 15, or the like. Suitable constructions, modifications, and options to and for the payoff station 110 will be apparent to those of skill in the art. Suitable payoff stations 110 include the DVD 630 from Setic of France.

[019] The first and second insulated conductors 13 and 15 travel from the guide plate 120 to a twist modulator 200, which is controlled by an encoder 170. The twist modulator 200 imparts a variable twist length to the first and second insulated conductors 13 and 15 to form a pre-twisted pair Al. The twist modulator 200 may also impart a variable twist length to the first and second insulated conductors 13 and 15 with a dielectric tape located therebetween to form the pre-twisted pair Al, if an embodiment like Figure 3A is desired. The pre-twist is slight and may be random or by an algorithm, in accordance with US Patent 8,616,247.

[020] The pre-twisted pair Al passes from the twist modulator 200 to the twinner station 140. The twinner station 140 may be of any suitable construction and may be of conventional design. Suitable twinners are available from Kinrei of Japan.

[021] The twinner station 140 includes a frame or housing 142 and a bow 152 mounted on first and second hubs 146 and 148 for rotation in a direction T. The pre-twisted pair Al passes through the first hub 146, around a first pulley 150, and through an entrance of a bow 152. As the bow 152 rotates about the first pulley 150, it imparts a twist to the first and second insulated conductors 13 and 15 (with the dielectric tape therebetween, if present) in a known manner, thereby converting the pre-twisted pair Al into a partially-twisted pair A2. The partially-twisted pair A2 continues through and out an exit to the bow 152 and around a second pulley 156 and through the second hub 148, and then onto a take-up reel 158.

[022] As the bow 152 rotates about the second pulley 156, it imparts more twist to the partially-twisted pair A2, thereby converting the partially-twisted pair A2 to the first twisted pair A. Notably, the twist imparted by the bow 152 at the first and second pulleys 150 and 156 is merely additive to the twist (positive and/or negative) in the pre-twisted pair Al. Therefore, the twist modulation introduced in the pre-twisted pair Al carries through to the twisted pair A. Additional information about the structure and functioning of a twinner can be found in at least US Patents 6,167,687 and 6,209,299, which are herein incorporated by reference.

[023] Two US Patents 11,923,106 and 10,978,224 have granted to Daikin Industries, Ltd. of Osaka, Japan. The two Patents are incorporated herein by reference. The Patents describe chilling insulated conductors to a temperature of less than five degrees Celsius prior to the twisting operation within a twinner, so as to avoid a crushing of the insulation layer at the points of contact between the twisted insulated conductors. Some embodiments, describe chilling the insulated conductors to less than zero degrees Celsius or even less than negative forty degrees Celsius. The chilling may be accomplished by a chilled fluid, a cryogenic liquid or a chilled gas. SUMMARY OF THE INVENTION

[024] The Applicant has appreciated that most of the crushing occurs within the twinning machine, which twists the insulated conductors together to form a twisted pair. The prior art’s theory is that the point of contact between the first insulated conductor and the second insulated conductor during the twisting is the primary source of the crushing of the insulation layers. However, the Applicant believes that some portion of the crushing also occurs within the bow of the twinner. The path of the partially twisted insulated conductors within the bow is affected by centrifugal forces due to the spinning movement of the bow. One method of gauging a position of the insulated conductors within the bow is to view an open bow with a strobe light in a low light condition and see if the insulated conductors are pressing against the radially outer curved wall of the bow or against the inner guides (or inner curved wall of the bow) as the bow is spinning.

[025] If the insulated conductors are pressing against the outer wall, this may cause some crushing of the insulation layers in contact with each other within the partially twisted pairs. Slowing the bow’s speed of rotation will tend to move the insulated conductors radially inward. Also, increasing the line speed of the insulated conductors may tend to move the insulated conductors radially inward. If the insulated conductors are pressing against the inner guides or inner wall of the bow, increasing the bow speed will tend to move the insulated conductors toward the outer wall of the bow. Also, decreasing the line speed of the insulated conductors may tend to move the insulated conductors radially outward.

[026] Adjusting the twinner to move the partially twisted insulated conductors into a midportion within the bow is a time-consuming process. It is believed that if the insulated conductors are not well centered within the bow, the insulation layers on the insulated conductors can suffer some crushing due to the forces against the outer wall of the bow or against the inner guides or inner wall of the bow. Even when the twinner is adjusted, the position of the insulated conductors within the bow can change as the ambient conditions change, such as temperature and humidity.

[027] Therefore, it is an object of the present invention to provide an effective force within the bow of a twinner to cause insulated conductors passing therethrough to tend to move radially inward away from an outer wall of the bow. This effective force will make balancing the bow’s rotational speed with the line speed easier as it will “open the window” of tolerance where the bow’s spinning speed in combination with the insulated conductors line speed through the bow results in the insulated conductors residing within the middle region of the bow.

[028] It is an object of the present invention to provide a cushion effect within the bow by introducing an air flow stream through the bow. The air flow stream will cause a force tending to move the insulated conductors away from the outer wall of the bow and radially inward toward an inner wall. The air flow stream will be flowing primarily against the outer wall of the bow as the air flow path is being constantly redirected by the curvature of the outer wall of the bow path from the entrance to the exit of the bow, or from the exit to the entrance of the bow if air is introduced from the end of the bow and exits at the entrance to the bow. Therefore, the insulated conductors will tend to be redirected by the air flow away from the outer wall. This will make locating the insulated conductors away from the outer wall easier because there will be a cushioning air flow which tends to blow the insulated conductors off, or away from, the outer wall.

[029] The air flow stream through the bow may be ambient air at an ambient temperature. However, in a further enhancement of the present invention, the air flow stream through the bow may be chilled.

[030] In the prior art of Daikin, a chilling operation is used to fortify the shape and dimensions of the insulation layer prior to a twisting operation. Simply stated, the shape and dimensions are made more rigid or stiff prior to a twisting operation due to the decreased temperature, so that the shape and dimensions of the insulation layer will resist crushing during the twisting operation. The chilling temperature is taught in the prior art to be effectuated within a cooling chamber and potentially within a secondary structure, such as a tube leading from the cooling chamber to the twinner.

[031] The Applicant has appreciated that the added structures in the path of the insulated conductor, such as the cooling chamber and the secondary structure add length to the manufacturing line and add costs to the manufacturing line. It is an object of the present invention that the air flow stream through the bow may be a chilling air flow stream with a temperature of less than fifteen degrees Celsius, such as less than ten degrees Celsius, most preferably less than five degrees Celsius. By this measure, the manufacturing line can be reduced in length. Also, the bow, which is already required by the twinner can serve the dual function of creating the helical twist and chilling the insulated conductors therein immediately prior to the helical twist.

[032] It is an object of the present invention to provide an alternative technique to prevent, minimize, or control insulation crush, which does not require chilling insulation layers of insulated conductors of twisted pairs. As such, the air flow stream through the bow of the twinner need not be a chilled air stream. However, it is an additional object of the present invention that if chilling of the insulation layers is desired, the air flow stream may be chilled to assist in the cooling of the insulation layers.

[033] These and other objectives are accomplished by a bow of a twinner for accepting first and second insulated conductors, which may include a dielectric tape located therebetween, to pass from a first end of the bow to a second end of the bow. The bow spins in rotation and helically twists the first and second insulated conductors, with the dielectric tape located therebetween, if the dielectric tape is included. A fitting is provided for feeding an air flow stream into one of the first or second ends of the bow, so that the air flow stream travels through the bow. Alternatively, the bow can collect air through one or more slots as the bow spins. The air flow stream is supplied to cushion the insulated conductors within the bow and reduce any crushing of insulation layers of the insulated conductors within the bow due to a centrifugal force. The air flow stream may optionally pass through plural through holes or nozzles in the bow and/or guides attached to the bow. The air flow stream may be at an ambient temperature, but may also be chilled to increase a compression modulus of the insulation layers.

[034] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[035] For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:

[036] Figure l is a perspective view of a twisted pair cable, in accordance with the prior art;

[037] Figure 2A is a cross sectional view taken along line II— II in Figure 1 showing crushing of insulation layers, in accordance with the prior art;

[038] Figure 2B shows a Table 1 with twist lengths, in accordance with the prior art;

[039] Figures 3 A and 3B are cross section views of a twisted pair and a twisted pair cable having a dielectric tape twisted between insulated conductors of each twisted pair, in accordance with the prior art;

[040] Figure 3C is a schematic view of a twinner, in accordance with the prior art;

[041] Figure 4 is a closeup schematic view of an air flow stream within a tubular bow for use in a twinner, in accordance with a first embodiment of the present invention;

[042] Figure 5 is a cross sectional view taken through a tubular bow, in accordance with a second embodiment of the present invention;

[043] Figure 6 is a cross sectional view taken through a tubular bow, in accordance with a third embodiment of the present invention;

[044] Figure 7 is a cross sectional view taken through an open bow with eyelets, in accordance with a fourth embodiment of the present invention; and

[045] Figure 8 is a cross sectional view taken along line VIII - VIII in Figure 7.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[046] The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[047] Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity. Broken lines illustrate optional features or operations unless specified otherwise.

[048] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

[049] As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as "between X and Y" and "between about X and Y" should be interpreted to include X and Y. As used herein, phrases such as "between about X and Y" mean "between about X and about Y." As used herein, phrases such as "from about X to Y" mean "from about X to about Y."

[050] It will be understood that when an element is referred to as being "on", "attached" to, "connected" to, "coupled" with, "contacting", etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, "directly on", "directly attached" to, "directly connected" to, "directly coupled" with or "directly contacting" another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed "adjacent" another feature may have portions that overlap or underlie the adjacent feature.

[051] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper”, “lateral”, “left”, “right” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the descriptors of relative spatial relationships used herein interpreted accordingly.

[052] Figure 4 is a closeup schematic view of a chilled or ambient temperature air flow stream 160 within a modified bow 152A for use in a twinner, in accordance with the present invention. The pre-twisted pair Al of the first and second insulated conductors 13 and 15 (with the dielectric tape therebetween, if present) from the modulator 200 passes to the first pulley 150. The pre-twisted pair Al passes over the first pulley 150 and through an opening 151 in a fitting 153 toward a first end 155 of the bow 152A. The fitting 153 may be fixed to the frame or housing 142 of the twinner 100.

[053] The pathway inside of the fitting 153 is considered a feed tube and carries the first and second insulated conductors 13 and 15 toward the modified bow 152A. The fitting 153 also carries the air flow stream 160 toward the modified bow 152A. An opening or input in the first end 155 of the bow 152A is rotatably coupled to an exit opening 157 of the fitting 153 by a slip coupling 146A. The slip coupling 146A allows the modified bow 152A to rotate, while keeping the fitting 153, which is fixed and does not rotate, connected thereto and in communication. The air flow stream 160, which is introduced upstream of the slip coupling 146A, does not substantially leak out at the junction between the end 157 of the fitting 153 and the first end 155 of the bow 152A. [054] The spinning motion of the bow 152A relative to the first pulley 150 causes the pre-twisted pair Al to become the partially-twisted pair A2, which is about a half of the twist length of the eventual twisted pair A. The partially-twisted pair A2 travels through the bow 152A to a second end 159 or exit of the bow 152A. The partially-twisted pair A2 then passes over the second pulley 156. The spinning motion of the bow 152A relative to the second pulley 156 causes the partially-twisted pair A2 to become fully twisted to the desired extent, i.e., the twisted pair A.

[055] It is interesting to note that the lower half of the bow 152A is considered a balance bow 165 or counterweight to the portion of the bow 152A which carries the partially-twisted pair A2, so that the overall bow 152A is balanced and the slip coupling 146A and the hub 148 may have an extended lifespan. Baffles 167 may be placed in the balance bow 165, if the balance bow 165 is hollow to prevent the air flow stream 160 from passing through the balance bow 165.

[056] In the embodiment shown in Figure 4, the fitting 153 feeds the air flow stream into the first end 155 of the bow 152A, so that the air flow stream 160 travels through the bow 152A in the same direction as the partially-twisted pair A2 and exits the bow 152A at the second end

159 of the bow 152A. However, it is also possible for the fitting 153 to be attached to the second end 159 of the bow 152Aby the slip coupling 146 A, so that the air flow stream 160 travels through the bow 152A in the opposite direction to the travel direction of the partially-twisted pair A2 and exits the bow 152A at the first end 155 of the bow 152A. In either instance, the air flow stream

160 cushions the insulated conductors 13 and 15 of the partially-twisted pair A2 within the bow 152A.

[057] In one embodiment, the air flow stream 160 is sourced from the ambient environment and at an ambient temperature. The air flow stream 160 will cause a force tending to move the insulated conductors away from the outer wall 161 of the bow and radially inward toward an inner wall 163. The air flow stream 160 will be flowing primarily against an inside surface of the outer wall 161 of the bow 152A as the air flow path is being constantly redirect by the curvature of the outer wall 161 of the bow path from the entrance at the first end 155 to the exit at the second end 159 of the bow 152A. Therefore, the partially-twisted pair A2 will tend to be redirected by the air flow stream 160 away from the outer wall 161. This will make locating the partially-twisted pair A2 of insulated conductors (which may include a dielectric tape between the insulated conductors) away from the inside surface of the outer wall 161 easier because there will be a cushioning air flow which tends to blow the parti ally -twisted pair A2 off, or away from, the outer wall 161.

[058] In addition to the cushioning effect, it may be desirable to increase a compression modulus of the partially-twisted pair A2 prior to the final twisting to form the twisted pair A. If so, the airflow stream 160 may be chilled so as to increase a compression modulus of the insulation layers. For example, the air flow stream 160 may be provided by a chiller at a temperature below fifteen degrees Celsius, more preferably below ten degrees Celsius, such as below five degrees Celsius.

[059] The bow 152A may become frosty and collect condensation from the air surrounding the twinner. Such an occurrence may cause the bow 152A to spin off moisture droplets and dampen the equipment close to the spinning bow. To reduce condensation on the bow and on the twisted pair A on the take up reel 158, a dehumidifier could be added to the twinner enclosure to remove moisture from the air within the twinner cabinet.

[060] By the present invention, it is possible to save on energy costs. In one embodiment, the invention is chilling only the interior of the bow 1 2A of the twinner with an air flow stream 160 of chilled air, e.g., below zero degrees Celsius. This would chill the outer surface of the first and second insulated conductors just before the final twisting operation. The space within the bow 152A is confined and would not be as expensive to chill. Such chilling may be sufficient in some circumstances, e.g., on longer twist lengths, so that an additional chilling chamber, e.g., liquid bath or spray nozzle bed, would not need to be added within the twinner cabinet or upstream of the twinner cabinet, as mentioned in US Patent 11,923,106. If such a chilling chamber were still needed, the cooling in the bow 152A should enable the chilling chamber to be made shorter so as to take up less space along the manufacturing line.

[061] Figure 5 is a cross sectional view taken through a tubular bow, in accordance with a second embodiment of the present invention. In the embodiment of Figure 5, the bow 152B includes a floor 201 within the bow 152B proximate an outer wall 203 of the bow 152B. The floor 201 includes a first surface 205 facing toward the outer wall 203 of the bow 152B and a second surface 207, opposite the first surface 205. [062] A plurality of through holes 209 (or nozzles) are formed within the floor 201, which function to pass the air flow stream 160 therethrough. An area between the outer wall 203 and the first surface 205 of the floor 201 functions as an air chamber 211 to carry the air flow stream 160. The plurality of through holes 209 are formed along a length of the floor 201, e.g., in rows and columns, and act to supply jets of air 213 to cushion the first and second insulated conductors passing through the bow 152B.

[063] In effect, the floor 210 is similar to an air hockey table which can float an air hockey puck on a cushion of air, against the force of gravity, which tends to press the air hockey puck into contact with the air hockey table. In the case of the bow 152B, the floor 210 is floating the partially twisted pair A2 off of the second surface 207 of the floor 210 on a cushion of air produced by the jets of air 213. The jets of air 213 operate against a centrifugal force of the spinning bow 152B, which tends to press the partially twisted pair A2 into contact with the second surface 207 of the floor 201.

[064] In the second embodiment of Figure 5, the bow 152B includes an inner wall 215, opposite the outer wall 203. Therefore, the bow 152B is formed as a closed-wall tube. The first and second insulated conductors (and any dielectric tape located therebetween) of the partially twisted pair A2 would be located between the second surface 207 of the floor 201 and the inner wall 215.

[065] Figure 6 is a cross sectional view taken through a tubular bow 152C, in accordance with a third embodiment of the present invention. The bow 152C is nearly the same as the bow 152B of Figure 5, except for the addition of one or more collection slots 221 formed within the bow 152C along the length of the bow 152C. The collection slots 221 collect ambient air 220, as the bow 152C spins about its rotation axis 223, which would be defined by hubs 146 and 148 in Figure 3C. As with Figure 5, the air collected by the one or more collection slots 221 would be used to create an air flow stream to travel through the bow 152C to cushion the first and second insulated conductors within the bow 152C.

[066] As the bow 152C spins, ambient air 220 would be driven into the one or more slots 221 and would pressurize the air chamber 211. To assist in pressurizing the air chamber 211, the first and second ends of the air chamber 211 may be closed off by baffles. The ambient air 220 in the air chamber 211 would pass through the plurality of through holes 209 formed within the floor 201 and generate the air jets 213, which cushion the partially twisted pair A2, as discussed above.

[067] An advantage of the embodiment of Figure 6 is that no air pump would be needed to create the air flow stream 160 in Figure 5. Rather, the energy of the spinning of the bow 152C would serve the extra function of creating the air pressure in the air chamber 211 needed to create the air jets 213. The side edges of the one or more slots 221 may be flared to collect more air and increase the air pressure within the air chamber 211.

[068] Figure 7 is a cross sectional view taken through an open bow 152D with eyelets 225, in accordance with a fourth embodiment of the present invention. Figure 8 is a cross sectional view taken along line VIII - VIII in Figure 7. The open bow 152D does not include any inner wall 215 and hence is considered “open,” as opposed to the closed-wall tube design shown in Figures 4-6. To keep the partially twisted pair A2 spinning along with the bow 152D, a plurality of eyelets 225 are attached to the bow 152D and extend radially inward from the bow 152D. The first and second insulated conductors, and any dielectric tape residing therebetween, are threaded through the eyelets 225 when the bow 152D is being set up to run.

[069] The plurality of eyelets 225 extend away from the second surface 207 of the floor 201. In one embodiment, the eyelets 225 may be simple, solid rings with a stem attached to the floor 201. In such a situation, the air jets 213 will assist in cushioning the partially twisted pair A2 away from the portion of the ring of the eyelet 225 closest to the floor 201. However, in an enhanced embodiment, the stems 227 attaching the eyelets 225 to the floor 201 are hollow. The hollow path inside the stem 227 passes to the second surface 205 of the floor 201 and is in communication with the air chamber 211.

[070] The rings 229 are also hollow and in communication with the hollow path in the stem 227, so that air may travel from the air chamber 211 into the hollow path within the ring 229. The rings 229 include at least one nozzle 231, which may take the form of through holes formed within a radially inner circular wall of the ring 229. Preferably, the nozzles 231 are spaced around the inner wall of the ring 229, such as the twelve nozzles depicted in Figure 8.

[071] By this arrangement, the air within the air chamber 211 is in communication with the hollow path within the stem 227, which is in communication with the hollow path within the ring 229, and air in the air chamber 211 can be expelled as air jets 233 from the nozzles 231 in the ring 229 of the eyelet 225 toward a center space 235 within the eyelet 225. The air jets 233 cushion the first and second insulated conductors passing through the eyelet 225. To enhance the cushioning effect, the eyelets 225 may have extended lengths, so as to form curved cylinders, tracking the curvature of the bow 152D, and multiple rows and columns of the nozzles 231 may be formed on the inner walls of the curved cylinders.

[072] Although Figures 7 and 8 show the bow 152D having a closed air chamber 211, which receives the air flow stream 160 from a pressurized source, the bow 152D may include the slot or slots of 221 of Figure 6 to receive ambient air from the spinning of the bow 152D. With air jets 133 being provided by the eyelets 225, the air jets 213 from the floor 201 may be no longer required. In such a case, the through holes 209 may be eliminated, and the floor 201 may be made solid except for the communication to the hollow stems 227. Although the air chamber 211 has been illustrated in the various embodiments as being within the shell of the curved bow 152B, 152C and 152D, the air chamber may be formed as a feature, e.g., a tubular member, attached to an outside of the shell of the curved bow 152B, 152C or 152D with a pathway or pathways communicating the air to produce the air jets 213 and/or 233. In all of the embodiments without a slot 221 to scoop in ambient air, the air chamber 211 may be supplied with chilled air, as detailed in relation to Figure 4.

[073] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.

Claims

We claim:

1. A twinner comprising: a bow for accepting first and second insulated conductors to pass from a first end of said bow to a second end of said bow, wherein said bow spins to twist the first and second insulated conductors together to form a twisted pair; and an air flow stream that travels through said bow and cushions the first and second insulated conductors within said bow.

2. The twinner according to claim 1, further comprising: a fitting feeding the air flow stream into one of said first or second ends of said bow.

3. The twinner according to claim 2, wherein the air flow stream exits said bow at the other of said first or second ends of said bow.

4. The twinner according to claim 3, wherein said fitting feeds the air flow stream into said first end of said bow, so that the air flow stream exits from said second end of said bow.

5. The twinner according to claim 2, wherein said fitting includes a slip coupling which connects a feed tube carrying the first and second insulated conductors into said first end of said bow.

6. The twinner according to claim 5, wherein the air flow stream enters said feed tube upstream of said slip coupling.

7. The twinner according to claim 2, wherein said air flow stream is at a temperature below fifteen degrees Celsius.

8. The twinner according to claim 7, wherein said air flow stream is at a temperature below ten degrees Celsius.

9. The twinner according to claim 8, wherein said air flow stream is at a temperature below five degrees Celsius.

10. The twinner according to claim 2, wherein said air flow stream is sourced from the ambient environment and at an ambient temperature.

11. The twinner according to claim 2, further comprising: a floor within said bow proximate an outer wall of said bow, and wherein said floor includes a first surface facing toward said outer wall of said bow and a second surface opposite said first surface; and a plurality of through holes formed within said floor which function to pass the air flow stream therethrough.

12. The twinner according to claim 11, wherein an area between said outer wall and said first surface of said floor functions as an air chamber to carry the air flow stream, and wherein said plurality of through holes are formed along a length of said floor and act to supply jets of air to cushion the first and second insulated conductors passing through the bow.

13. The twinner according to claim 12, wherein said bow further includes an inner wall opposite said outer wall, so that said bow is formed as a closed wall tube, and wherein the first and second insulated conductors passing through the bow pass between said second surface of said floor and said inner wall.

14. The twinner according to claim 12, wherein said bow further includes a plurality of eyelets extending away from said second surface of said floor, and wherein the first and second insulated conductors pass through said plurality of eyelets.

15. The twinner according to claim 14, wherein each of said plurality of eyelets has a hollow stem which is connected to said floor and in communication with said air chamber, and wherein each of said plurality of eyelets includes at least one nozzle in communication with said hollow stem to expel air from said eyelet toward a center space within said eyelet to cushion the first and second insulated conductors passing through said eyelet.

16. The twinner according to claim 2, wherein said bow further includes an air chamber to carry the air flow stream, and a plurality of eyelets extending radially inward from said bow.

17. The twinner according to claim 16, wherein each of said plurality of eyelets has a hollow stem which is in communication with said air chamber, and wherein each of said plurality of eyelets includes at least one nozzle in communication with said hollow stem to expel air from said eyelet toward a center space within said eyelet to cushion the first and second insulated conductors passing through said eyelet.

18. The twinner according to claim 2, wherein said bow also accepts a dielectric tape along with the first and second insulated conductors, and wherein said bow spins to twist the first and second insulated conductors together with the dielectric tape being located therebetween to form the twisted pair.

19. The twinner according to claim 1, further comprising: one or more collection slots formed within said bow to collect ambient air as said bow spins and create the air flow stream that travels through said bow and cushions the first and second insulated conductors within said bow.

20. The twinner according to claim 19, further comprising: a floor within said bow proximate an outer wall of said bow, and wherein said floor includes a first surface facing toward said outer wall of said bow and a second surface opposite said first surface; and a plurality of through holes formed within said floor which function to pass the air flow stream therethrough.

21. The twinner according to claim 20, wherein an area between said outer wall and said first surface of said floor functions as an air chamber to receive the ambient air from said one or more collection slots, wherein said plurality of through holes are formed along a length of said floor and act to supply jets of air to cushion the first and second insulated conductors passing through the bow.

22. The twinner according to claim 21, wherein said bow further includes an inner wall opposite said outer wall, so that said bow is formed as a closed wall tube, and wherein the first and second insulated conductors passing through the bow pass between said second surface of said floor and said inner wall.

23. The twinner according to claim 21 , wherein said bow further includes a plurality of eyelets extending away from said second surface of said floor, and wherein the first and second insulated conductors pass through said plurality of eyelets.

24. The twinner according to claim 23, wherein each of said plurality of eyelets has a hollow stem which is connected to said floor and in communication with said air chamber, and wherein each of said plurality of eyelets includes at least one nozzle in communication with said hollow stem to expel air from said eyelet toward a center space within said eyelet to cushion the first and second insulated conductors passing through said eyelet.

25. The twinner according to claim 19, wherein said bow further includes an air chamber to hold the air collected by said one or more collection slots, and a plurality of eyelets extending radially inward from said bow.

26. The twinner according to claim 25, wherein each of said plurality of eyelets has a hollow stem which is in communication with said air chamber, and wherein each of said plurality of eyelets includes at least one nozzle in communication with said hollow stem to expel air from said eyelet toward a center space within said eyelet to cushion the first and second insulated conductors passing through said eyelet.

27. The twinner according to claim 19, wherein said bow also accepts a dielectric tape along with the first and second insulated conductors, and wherein said bow spins to twist the first and second insulated conductors together with the dielectric tape being located therebetween to form the twisted pair.