Patent Application
20180093852
This invention relates to a reel assembly for gathering in and paying out cords and cables, most advantageously electric power cords, data cables, or other conductor cords of portable electrical and electronic devices, tools, and other electrical or electronic devices where it is desired to move the devices around during use.
Retractable cord reels have been widely used in many applications, especially in telephonic applications. In some cord reels, the reel is spring biased so that the cord is under a constant tension when a length of cord is pulled from the reel, and automatically rewinds back onto the reel when tension is released. In other designs, the reel includes a catch or latching mechanism so that certain lengths of cord can be unwound from the reel and can be utilized without the withdrawn cord being under constant tension. Such reels also include a mechanism for automatically rewinding the cord back onto the reel when the device is no longer in use.
Many cord reels utilize a coil of flat flexible cable (FFC) as part of the data transmission circuit in the device (see e.g., U.S. Pat. No. 6,293,485 to Hollowed for one such reel design). Some forms of conventional FFC generally comprises a number of fine wires embedded within a polymeric matrix. Typically, the wires are laminated between one or more layers of a dielectric polymer sheet material, such as a polyester. Typically all of the wires are of the same size across the entire cable width. In other forms of FFC the wires are actually printed metallic traces (i.e., the FFC is a flexible printed circuit board).
Currently, FFC can be manufactured with a cable width and thickness suitable to meet USB 1.1 standards for data transmission but still fit within a relatively compact cord reel apparatus that can be conveniently mounted in, e.g., an airline seat back for use in conjunction with a telephone or game controller by passengers in flight. There is an increasing demand for corded devices that utilize a cord reel that meets USB 2.0, USB 3.0 or other standards for data and power transmission (i.e., battery charging). Cord reel designs that utilize a segment of FFC along with a conventional round-profile cord require splices from the FFC to round cord segments, which can lead to undesirable signal and power losses.
U.S. Pat. No. 3,695,544 to William J. Morey, Sr. describes a cord reel assembly that utilizes a single unitary round-profile cord, in which a majority of the cord is wound about a main cord storage compartment and a portion of the cord is wound in an adjacent disk-shaped take-up compartment having a thickness of approximately the diameter of the cord, so that the cord in the take-up compartment is constrained from flexing upward as the section of cord winds and unwinds. While this design does not include splices in the cord as in FFC-type reels, the configuration of the take-up compartment requires that the diameter of the cord reel assembly must be relatively large compared to the length of cord that can be withdrawn from the reel. The cord reel was designed for use with electrical appliances, machine tools and the like, and does not address the needs of modern electronic devices. Modern applications for cord reels often require a relatively small reel diameter relative to the desired necessary cord length that can be withdrawn from the reel, rendering the early unitary-cord reel design unsuitable for modern electronic data transfer applications.
There is an ongoing need for improved cord reel designs. The present application addresses this need.
A retractable cord reel assembly, as described herein, comprises a reel rotatably supported within a housing or frame for rotation about an axis, a biasing spring engaged with the reel, and a single unitary electrically-conductive cord (e.g., a serial data transfer cable) having a distal end portion affixed to the housing or frame and a movable proximal end. The cord is wound about the reel in a plurality of contiguous segments. The cord reel of the cord reel assembly comprises separate coaxial cord-take-up and cord-storage compartments, having, in an initial cord configuration, a fixed-length segment of cord wound in a spiral around a hub in the cord-take-up compartment, and a plurality of helical windings of the cord in the cord-storage compartment. The take-up compartment is designed to allow the spiral of cord therein to flex and become non-planar as cord is withdrawn from and retracted back into the storage compartment. The flexing of the cord in the take-up chamber surprisingly allows for a much smaller cord reel relative to the length of withdrawable cord than prior art unitary-cord reel designs. The cord reel assembly described herein is specifically designed for use in in modern electronic data and power transmission applications without the significant losses of signal integrity or power, commonly associated with conventional cord reel assemblies.
As described herein, a retractable cord reel assembly for an electronic or electric device or for connection of different electronic and electrical devices, utilizes a single, unitary electrically conductive cord or cable wound in distinct segments about a two compartment reel. The cord reel assembly has significant advantages over prior known cord reels that utilize multiple connected portions of cords or cables within the reel, because the unitary cord ameliorates the signal and power losses that are inherent in reels comprising multiple distinct electrically connected cords. Additionally, the unique cord take-up compartment design described below allows cord reels of much smaller size for a given desired cord diameter to be constructed compared to the single cord depth take-up compartment of the prior art unitary cord reel described above. The reel is rotatably supported on a frame (e.g., a housing) and is spring-biased into a given reference position. The reel includes a peripheral annular cord storage compartment surrounding a central cord storage hub, and having a depth (i.e., an extent in the axial direction) and a radial extent each equal to a plurality of cord thicknesses.
The reel also includes an annular cord take-up compartment surrounding a cord take-up hub positioned coaxial with and adjacent the cord storage compartment. The cord storage hub and the cord take-up hub are adapted and configured to rotate together about the same axis. The take-up compartment has a maximum depth in a region adjacent the cord take-up hub greater than one cord diameter, and preferably sufficient to allow a portion of the cord in the cord take-up compartment to flex in the direction of the rotational axis of the reel (e.g., about 1.5 to 3 cord diameters or greater), and preferably has a radial extent from the take-up hub to the periphery of the take-up compartment that is greater than the radial extent of the cord storage compartment from the cord storage hub to the periphery of the storage compartment. The cord storage compartment preferably has a depth in the axial direction that is greater than the maximum depth of the take-up compartment and is sufficient to accommodate multiple overlapping helical windings of the cord. The cord take-up compartment can have a uniform depth or can have a greater depth in the region of the take-up hub relative to the region of the periphery of the cord take-up compartment. In some embodiments, the cord storage compartment has a depth that is greater near or at the cord-storage hub than at the periphery thereof, e.g., having a peripheral depth that is less than the depth at the hub, and which is slightly larger than one cord diameter so as to accommodate a portion of a cord without significant binding or flexing in the axial direction as the reel is operated. The depth of the cord take-up compartment can vary smoothly from hub to periphery, in a step fashion from hub to periphery, or in some combination of smooth and step variance.
Different segments of a single, unitary cord are wound around the respective hubs of the cord storage and cord take-up compartments with a transitional segment passing through the take-up and storage hubs. The cord preferably meets modern electronic serial data transfer and charging protocols such as, e.g., USB 2.0, USB 3.0, FireWire, Thunderbolt, and the like. A distal end portion of the cord is affixed to a feature at the periphery of the cord take-up compartment, such as a frame or housing, that is rotationally stationary relative to the reel. The distal end of the cord extends out from the frame or housing and is adapted for electrical connection to an electric or electronic device or apparatus, e.g., connection to a power source and/or data processing unit for the electric or electronic device. A fixed-length segment of cord between the distal end portion and the hub of the take-up compartment is wound around the cord take-up hub in a plurality of spiral turns, while a moveable segment of cord is wound around the storage hub in a plurality of helical windings. The transitional segment of the cord between the fixed-length segment and the movable segment passes through the cord take-up and cord storage hubs. The portion of the cord that passes through the hubs remains substantially affixed within a channel or passageway that extends through the hubs (e.g., by friction and/or the windings of the moveable segment). The moveable segment of the cord is wound around the cord storage hub in the same winding direction as the spiral of the fixed-length of the cord that is wound around the cord take-up hub when the reel assembly is in its initial cord storage configuration.
A biasing spring (e.g., a spiral spring) is operably connected to the reel to automatically retract the cord back onto the reel after cord has been withdrawn therefrom. Preferably, a locking mechanism (e.g., a ratchet mechanism) is engageable with the reel to arrest the retraction of the cord after a predetermined length of cord is withdrawn. Disengaging the locking mechanism then allows the cord to be retracted.
The fixed-length segment of cord wound within the take-up compartment is approximately half the length of the maximum length of cord that is intended to be withdrawn from the reel during use of the cord reel assembly. The portion of cord wound within the cord storage compartment when the reel is in an initial rotational state is longer than the maximum length of cord that can be withdrawn from the reel during use. The fixed-length segment of cord in the cord take-up compartment is wound in a relatively tight one-dimensional spiral around the take-up hub in the initial cord storage configuration of the reel assembly, while the portion of cord in the cord storage hub typically is wound in overlapping layers of helical windings.
In use, the frame or housing of the reel assembly is generally affixed to a surface, or otherwise maintained in a stationary state, and a pulling force greater than the biasing force of the spring is applied to the proximal end of the cord, causing the reel to rotate relative to the frame, and causing a portion of the cord in the cord storage compartment to unwind and withdraw from the reel. Simultaneously, the rotation of the reel causes the spiral windings in the take-up compartment to loosen and expand radially toward the periphery of the take-up compartment. The depth of the take-up chamber allows at least the windings nearest the take-up hub to flex slightly in the direction along the rotational axis, which ameliorates binding of the fixed-length of cord as the spiral windings loosen and allows a longer spiral segment to be wound around the take-up hub for a given cord diameter and reel diameter. Once a length of cord approximately equal to the fixed-length segment in the take-up compartment is withdrawn, the rotation of the reel causes the cord in the take-up compartment to rewind on the take-up hub in the opposite direction to the initial spiral winding. When the fixed-length of cord in the take-up compartment is fully rewound in a tight spiral around the take-up hub, no more cord can be withdrawn from the reel. The locking mechanism, if present, keeps the cord from retracting back into the reel when the pulling force is abated. The biasing spring automatically retracts the cord back onto the reel when the locking mechanism is disengaged.
In some embodiments, the cord reel assembly comprises: (a) a reel rotatably supported within a housing for rotation about an axis; (b) a biasing spring engaged with the reel; and (c) an electrically conductive cord having a distal end portion affixed to the housing, a movable proximal end, and a diameter. The cord is wound about the reel in a plurality of contiguous segments. The housing comprises a first planar member perpendicular to the axis of rotation of the reel, a second planar member spaced from and parallel to the first planar member, and a peripheral wall connecting the first and second planar members substantially surrounding the reel. The peripheral wall defines an opening through which the proximal end of the cord extends.
The reel comprises a cord take-up portion adjacent the first planar member of the housing and a cord storage portion coaxial with and axially spaced from the cord take-up portion in the direction of the second planar member of the housing. The cord take-up portion of the reel comprises a central take-up hub and an annular cord take-up platform connected to and surrounding the take-up hub. The cord take-up platform is spaced from the first planar member of the housing to define an annular cord-take-up compartment between the first planar member and the take-up platform. The spacing between the first planar member of the housing and the take-up platform is greater than one cord diameter in a region immediately adjacent the take-up hub and at least one cord diameter near the peripheral wall of the housing.
The cord storage reel portion comprises a cord storage hub that is coaxial with the cord take-up hub. One axial end of the cord storage hub is connected to the cord-take-up platform and the other axial end of the cord storage hub is connected to a cord storage platform that is spaced from the cord take-up platform, such that the cord take-up hub, the cord take-up platform, the cord storage hub and the cord storage platform rotate together about the same axis of rotation. The spacing between the cord storage platform and the take-up platform defines a cord storage compartment.
A fixed-length segment of the cord is disposed in a spiral winding between the distal end portion of the cord and a transitional segment of the cord that extends through a passageway within the take-up hub and the storage hub. A movable segment of the cord extends from the transitional segment to the proximal end of the cord. The movable segment of cord is at least twice as long as the fixed-length segment of cord in the take-up compartment. In an initial cord storage configuration, the moveable segment of cord is disposed in a plurality of helical windings around the cord storage hub in the same winding direction as the spiral winding of the fixed-length segment of cord in the take-up compartment.
In use, when a pulling force is applied to the proximal end of the cord, the reel rotates thereby unwinding the moveable segment of cord from the cord storage hub and withdrawing the movable segment out of the cord storage compartment. The biasing spring exerts a rotational biasing force opposed to the pulling force. The rotation of the reel causes the spiral of the fixed-length segment of cord in the take-up compartment to begin unwinding, thereby expanding the spiral toward the peripheral wall of the housing. As a portion of the moveable segment of cord longer than the fixed-length segment is withdrawn from the cord storage compartment, the continued rotation of the reel causes the fixed-length segment of cord in the take-up compartment to rewind around the take-up hub in the opposite direction to the helical windings in the cord storage compartment. When a portion of the moveable segment of cord about twice as long as the fixed-length segment has been withdrawn from the cord storage compartment, no more cord can be unwound from the cord storage hub. When the pulling force is abated, the biasing spring urges the reel to rotate in the opposite direction to the rotation caused by the pulling force. This results in the retraction of the moveable segment of cord back onto the cord storage hub in a reversal of the unwinding action caused by the pulling force. The spiral unwinding and rewinding actions in the take-up compartment are also reversed, so that when the entire second length of cord is rewound onto the cord storage hub, the reel assembly is back in the initial cord storage configuration. The spacing between the first planar section of the housing and the take-up platform allows the unwinding spiral to flex upward in the region near the take-up hub during unwinding of the spiral, thus allowing a longer fixed-length segment of cord to be used in the take-up compartment relative to the diameter of the reel compared to prior art reel assemblies in which the take-up compartment is uniformly only about one cord diameter is depth, which inhibits cord flexing. The cord flexing accommodated by the larger depth of the cord take-up compartment of the cord reel assemblies described herein, combined with the use of a single unitary cord, advantageously allows greater miniaturization of the cord reel assembly so that the cord assembly can be used in modern electronic device applications. Another significant advantage of the reel assemblies described herein is that cords meeting modern data and power standard such as USB 2.0 or 3.0, can be used without significant signal and power losses due to, e.g., cord splices, that are problematic for cord reel assemblies using an FFC as part of the reel design.
In some embodiments, the cord take-up platform is bowl-shaped with a peripheral rim and a depressed region adjacent the take-up hub. The rim is spaced at least one cord diameter from the first planar member of the housing. The depressed region is spaced at least about two cord diameters from the first planar section of the housing.
The cord reel assemblies described herein also can include a releasable locking mechanism to arrest rewinding of the reel in a selectable manner.
While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention.
Referring now to
Referring to
A locking mechanism 90 comprises base plate 92 mounted to lower housing member 18. As best shown in
Ratchet gear 100 includes twelve bottom teeth 103 and a six top gear teeth 102. The top teeth 102 are disposed in substantially uniform spaced relation to each other around the wheel, as are the bottom teeth 103. The bottom teeth 103 are arranged such that the base of a bottom tooth 103 is aligned with the base of a top tooth 102 and such that the base of a bottom tooth 103 is disposed substantially in the center between each pair of adjacent top teeth 102. The bottom teeth 103 preferably are shaped in triangles that include one side having an acute angle and another side having an obtuse angle with respect to the base. The top teeth 102 preferably are shaped in generally isosceles triangles. When twelve bottom teeth and six top teeth are used, the arc defined by each pair of adjacent bottom teeth 103 is approximately 30 degrees, and the arc defined by each pair of adjacent top teeth 102 is approximately 60 degrees.
Lever arm 98 of sensor 94 engages with top gear teeth 102 on ratchet gear 100. Back-rotation arresting arm 110 of base plate 92 is positioned to engage with lower teeth 103 of ratchet gear 100, to allow rotation of gear 100 in only one direction. Sensor spring 116 is mounted on pin 84 of base plate 92 adjacent sensor 94 and is arranged and adapted so that one of arms 86 of spring 116 contacts sensor 94 to bias sensor tip 104 to point in the direction radially outward from the axis of rotation of reel 12. The locking mechanism 90 is positioned so that sensor tip 104 can engage with internal gear teeth 106 surrounding a portion of spring receiving chamber 72 underneath storage reel 40, and thereby sense rotation of reel 12. As sensor tip 104 is engaged with internal gear teeth 106 of storage reel 40, lever arm 98 engages with teeth 102 of ratchet gear 100 and base lever arm 93 engages with recessed teeth 103 of gear 100, thereby arresting back rotation of the reel 12 while the internal gear teeth 106 are engaged with sensor tip 104. Sensor spring 116 insures that the sensor tip 104 will move into engagement with the internal gear teeth 106 when rotation of reel 12 brings teeth 106 into alignment with sensor 94 by biasing the tip 104 toward the periphery of chamber storage hub 40.
When reel 12 is rotated by withdrawing a portion of cord 14 from storage reel 40, biasing spring 44 is compressed by tightening of the spiral winding thereof. When the pulling force on the withdrawn cord 14 is released, the spring causes reel 12 to rotate back in the opposite direction. When the reel has rotated back sufficiently such that tip 104 can engage with internal gear 106, the locking mechanism can halt the back rotation. Additional details of the components of locking mechanism 90 are shown in
As shown best in
The fixed-length of cord 34 wound within the take-up compartment is approximately half the length of the maximum length of cord that is intended to be withdrawn from the reel during use of the cord reel assembly. The helically wound portion 70 of cord 14 within the cord storage compartment 140 when reel 12 is in an initial cord storage configuration (
In use, the housing 11 of the reel assembly 10 is generally affixed to a surface or otherwise held stationary and a pulling force greater than the biasing force of the biasing spring 44 is applied to the proximal end 20 of the cord 14, causing reel 12 to rotate relative to the housing 11, and causes a portion of the cord 14 in the cord storage compartment to unwind and withdraw from reel assembly 10. Simultaneously, the rotation of reel 12 causes the spiral winding of fixed-length segment 34 of cord 14 in the take-up compartment 120 to loosen and expand radially toward the periphery of the take-up compartment 120 (
The locking mechanism 90 keeps the withdrawn cord 14 from retracting back into cord storage compartment 140 when the pulling force on cord 14 is abated or removed. When locking mechanism 90 is disengaged, biasing spring 44 automatically causes cord 14 to withdraw back into cord storage compartment 140 to helically wind around hub 42. If he length of cord withdrawn from storage compartment 140 is longer than fixed-length segment 34, the spiral winding of fixed-length segment 34 of cord 14 in cord take-up compartment 120 loosens and unwinds until a length of cord 14 about equal to fixed-length segment 34 is wound around hub 42, at which point continued rotation of reel 12 to rewind around more of cord 14 into storage compartment 140 causes the fixed-length segment 34 to rewind in the same direction as the helical windings 70 until the entire withdrawn portion of cord 14 is rewound on hub 42. At this point, reel assembly 10 is back in the initial cord storage configuration.
All the parts of the reel assembly, except for example, the screws, are preferably made of a suitable molded synthetic plastic material, although they could be made of metal. It is apparent that the present invention provides an exceedingly compact and economical cord reel construction. It should be understood that numerous modifications may be made in the most preferred form of the invention described without deviating from the broader aspects of the invention.
All references, including publications, patent applications and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. the terms “cord” and “cable” are used herein interchangeably to refer to insulated electrically conductive wires, cords, cables and the like, and are to be given their common meaning in the electric and electronic arts. The use of the terms “a” and “an” and “the” and similar referents in the context of describing the present invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of terms “including”, “having” and “comprising” and like terms are to be construed as open ended terms, meaning including, but not limited to, unless otherwise indicated, or clearly contradicted by context, herein. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the present invention and does not pose a limitation on the scope of the claimed invention. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
The foregoing is an integrated description of the invention as a whole, not merely of any particular element or facet thereof. The description describes “preferred embodiments” of this invention, including the best mode known to the inventors for carrying it out. Of course, upon reading the foregoing description, variations of those preferred embodiments will become obvious to those of ordinary skill in the art. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is possible unless otherwise indicated herein or otherwise clearly contradicted by context.
This application claims the benefit of U.S. Provisional Patent Application No. 62/402,097, filed on Sep. 30, 2016, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62402097 | Sep 2016 | US |
