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CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to a provisional application, U.S. Ser. No. 62/341,175, filed May 25, 2016, entitled Remote Controlled Retractable Leg Iron, by Lee A. Reed, et al., which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates generally to leg restraint irons. In particular, the invention is related to a retractable leg restraint device which is controlled by a remote control. Leg irons are commonly known in the art and are often used by police and other authorities to restrain prisoners or inmates so that the prisoner or inmate is restricted from running or escaping. However, existing leg irons are limited in that the chain or wire connecting the cuffs have a fixed length. The length of this chain or wire has to be long enough to permit the prisoner to walk. However, this length also allows prisoners to escape as the movement of their legs is only partially restricted. A retractable leg iron which can be controlled by remote control solves this problem by making the length of the chain or wire adjustable so that the leg irons can have a sufficient length for movement when the prisoner is being transported but can actively be shortened for transport to prevent incidents or should the prisoner attempt to escape or need to be controlled. 
     SUMMARY OF THE INVENTION 
     Accordingly, the invention is directed to retractable leg irons which are controlled by a remote control unit. The remote controlled retractable leg irons prevent escapes by severely limiting the stride of the wearer, making running impossible and walking very difficult. They give any officer complete control over the mobility and movement of an inmate while in transport. When the remote is activated, and the emergency remote button is pushed, the remote controlled retractable leg irons start retracting the chains or cables, pulling the legs and feet of the wearer together, limiting the person&#39;s movement and mobility. The escapee is forced to stop the flight attempt, and officers are able to safely regain control. 
     The remote controlled retractable leg irons increase officer reaction time to prevent an incident or an escape. By restricting movement of the prisoner, the remote controlled retractable leg irons reduce the need for use of more elevated force measures. Finally, unlike conventional leg irons, due to its retractable capabilities, the device allows for easier movement of the wearer when not in emergency mode, and the device is easy to store away without bulky chains hanging over. 
     Additional features and advantages of the invention will be set forth in the description which follows, and will be apparent from the description, or may be learned by practice of the invention. The foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The accompanying drawings are included to provide a further understanding of the invention and are incorporated into and constitute a part of the specification. They illustrate one embodiment of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  shows a front view of the retractable leg irons, displaying the housing unit, the battery cover, the remote sensor window, the wires, and the cuffs. 
         FIG. 2  shows a front interior view of the retractable leg irons, displaying the housing unit, the power source, the remote sensor, the control unit, the servomotors, the winch drums, the wires, and the cuffs. 
         FIG. 3  shows a perspective view of the remote control, displaying the remote housing, the digital display, the transmitter, the power button, the voltage adjustment button, the reset button, the emergency button, the shock button, and the charging port. 
         FIG. 4  shows a stylized view of a wearer of the device in motion, during normal operating mode; as the legs come closer together mid-stride, the device automatically retracts, and as the stride lengths out, the cables extend out from the housing unit once more. 
         FIG. 5  shows a stylized view of a wearer of the device depicted in  FIG. 4 , first with the device in extended mode, with the cables extended from the housing unit, and then with the device in closed mode, with the cables retracted within the housing unit and the cuffs positioned adjacent to the housing unit. 
         FIG. 6  shows a stylized view of a wearer of an alternative embodiment of the device in motion, during normal operating mode; as the legs come closer together mid-stride, the device automatically retracts, and as the stride lengths out, the single cable extends out from the housing unit once more. 
         FIG. 7  shows a stylized view of a wearer of the device depicted in  FIG. 6 , first with the device in extended mode, with the single cable extended from the housing unit, and then with the device in closed mode, with the cable retracted within the housing unit and the first cuff positioned adjacent to the housing unit. 
         FIG. 8  shows a stylized view of a wearer of yet another alternative embodiment of the device in motion, during normal operating mode; as the legs come closer together mid-stride, the device automatically retracts, and as the stride lengths out, the single cable extends out from the first and second housing units once more. 
         FIG. 9  shows a stylized view of a wearer of the device depicted in  FIG. 8 , first with the device in extended mode, with the single cable extended from the first and second housing units, and then with the device in closed mode, with the cable retracted within the first and second housing units. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the invention in more detail, the invention is a remote controlled retractable leg iron  10 . 
     The first exemplary embodiment provides a housing unit  11 . See  FIG. 1 . The housing unit  11  is preferably cylindrical in shape, has a hollow interior  9 , and provides circular apertures  41  at each end, though other shapes and configurations will also work. The housing unit  11  must be rugged; preferably, it is made of an alloy for strength and light weight, such as magnesium alloy, though other materials, such as aluminum, carbon fiber composites, and the like may be used. Within the housing unit  11  is a retraction means. In one embodiment, the retraction means comprises a left winch drum  12  and a right winch drum  13 . See  FIG. 2 . The winch drums  12 , 13  are preferably mounted in a vertical position. Cable guides may be associated with the winch drums  12 , 13  to avoid tangling during retraction. Attached to the left winch drum is a left cable  14  and attached to the right winch drum  13  is a right cable  15 . The cables  14 , 15  can be manufactured from any suitable material, such as titanium steel rope wire, flexible sheet metal, galvanized steel, carbon fiber, reinforced webbing, etc. Opposite the ends of each cable  14 , 15  that are attached to the winch drums  12 , 13  are a pair of cuffs  16 , 17 . The cuffs  16 , 17  are preferably standard hand/leg cuffs with a pawl locking mechanism such that the cuffs can be securely fastened around the lower leg of the wearer. 
     In a closed position, the cables  14 , 15  are coiled around their respective winch drums  12 , 13  until the cuffs  16 , 17  rest against the circular apertures  41  on the ends of the housing unit  11 , and the winch drums  12 , 13  are locked in position and do not rotate. When in a normal operation mode the retractable leg irons are free to move into an extended position. In the extended position, the winch drums  12 , 13  freely rotate so that the cables  14 , 15  are free to extend outward from the housing unit  11  and automatically retract into the housing unit  11  whenever there is slack on the cables  14 , 15 , similar in function to a centrifugal clutch mechanism that provides the automatic retraction function of a seatbelt. When the cables  14 , 15  retract into the housing unit  11 , each cable  14 , 15  is coiled around the respective winch drum  12 , 13  and when extending from the housing unit  11 , each cable  14 , 15  is uncoiled from the respective winch drum  12 , 13 . See  FIGS. 4 and 5 . 
     In an alternative embodiment of the device  10 , a single winch drum is used. The ends of the cables  14 , 15  are each attached to the single winch drum. Rotation of the single winch drum in one direction winds the cables  14 , 15  around the single winch drum, and rotation of the single winch drum in the opposite direction unwinds the cables  14 , 15  from the single winch drum. 
     In yet another an alternative embodiment of the device  100 , a single cable  140  is used, with a winch drum located within the housing unit  110 . The first end of the cable  140  is attached to the winch drum, and the second end of the cable  140  is attached to the second cuff  17 . The first cuff  16  is attached to the housing unit  110 . Rotation of the winch drum in one direction winds the cable  140  around the winch drum, and rotation of the winch drum in the opposite direction unwinds the cable  140  from the winch drum. See  FIGS. 6 and 7 . 
     In yet another an alternative embodiment of the device  200 , a single cable  240  is used with a first housing unit  210  and a second housing unit  212 . Within each housing unit  210 , 212  is a single winch drum. The first end of the cable  240  is attached to the winch drum located in the first housing unit  210 , and the second end of the cable  240  is attached to the winch drum located within the second housing unit  212 . The first cuff  16  is attached to the first housing unit  210  and the second cuff  17  is attached to the second housing unit  212 . Rotation of the winch drums in a first winding direction winds the cable  240  around the respective winch drums, and rotation of the winch drums in the opposite second unwinding direction unwinds the cable  240  from the respective winch drums. See  FIGS. 8 and 9 . 
     The housing unit  11  further provides a sensor  40 . The sensor  40  is capable of receiving a signal from a remote control unit  30  and communicating that signal to a control unit  18 . The sensor  40  is preferably located on the top edge of the housing unit  11  and is embedded within the housing unit  11  below a window  20 . The control unit  18  may be a micro processor having logic control. In one embodiment it is manifest as a programmable multi-function printed circuit board. The control unit  18  is powered by a battery pack  19  contained within the housing unit  11 . The battery pack  19  is preferably removable from the housing unit  11  and is accessible through a removable battery door  21 . To prevent easy access to the battery pack  19  the battery door  21  may be secured by screws or other fasteners requiring tools for removal. The housing unit  11  may have a charging port  43  in communication with the battery pack  19  if the battery pack  19  comprises rechargeable batteries. In the embodiments of the invention where multiple housing units  210 , 212  are used, each comprises a sensor, a control unit, and a battery pack, as described herein. 
     The housing unit  11  further provides a means of actively retracting the cables  14 , 15 . The means of actively retracting the cables  14 , 15  is preferably a set of electric servomotors  22 , 23  which are attached to the winch drums  12 , 13 . The servomotors  22 ,  23  are in connection with and controlled by the control unit  18  and are powered by the battery pack  19 . In the emergency mode, the servomotors  22 , 23  rotate the winch drums  12 , 13  in the direction which coils the cables  14 , 15  around the winch drums  12 , 13  until the retractable leg irons  10  are in the closed position (i.e., the cuffs  16 , 17  are resting against the apertures  41  at the ends of the housing unit  11 ). The winch drums  12 , 13  are then locked into place so that the cables  14 , 15  cannot extend outward from the housing unit  11 . This may be accomplished in any number of known ways, for example, by having an actuator move a pin into and aperture in the winch drum, thereby preventing rotation. In the embodiment using a single winch drum, a single servomotor may be used. In the embodiments of the invention where multiple housing units  210 , 212  are used, each comprises a servomotor. 
     In one embodiment of the device, the servomotors  22 , 23  are located proximate to the winch drums  12 , 13 , in a vertical orientation. Each servomotor  22 , 23  has a central axle which rotates when said servomotor is activated. Attached to the axle is a pulley, with the pulley oriented horizontally, at a substantially perpendicular orientation to the axle. A belt drive runs from the pulley to the winch drum. When the servomotor is activated, the axle rotates, thereby rotating the pulley and causing the belt drive to rotate the winch drum. Other configuration of the servomotor and its relationship to the winch drum are also contemplated. 
     The device may have an automatic retraction function, whereby the cables  14 , 15  automatically retract into the housing unit  11  in the absence of any force applied to extend the cables  14 , 15  from the housing unit  11 . This improves the wearability of the device, whereby when the wearer takes a stride, as the wearer&#39;s legs come closer together excess length of the cables  14 , 15  is automatically retracted into the housing unit  11 , and as the wearer&#39;s legs move apart from each other the cables  14 , 15  extend from the housing unit  11 . This minimizes the potential for tripping while walking with the device. Note that this automatic retraction function is separate from the active retraction function that employs the servomotors  22 , 23  to forcibly retract the cables, notwithstanding any action by the wearer to avoid retraction. In order for the automatic retraction feature to work, the retraction means employs a biasing mechanism  50 . In one embodiment, the biasing mechanism  50  is associated with the winch drums  12 , 13 . Each winch drum comprises an element of the biasing mechanism  50  that rotates that winch drum in the first winding direction when there is no tension on the associated cable. The biasing mechanism  50  may be a pair of coil tension springs located at the top and bottom of the winch drum which rotate the winch drum in the first winding direction, thereby retracting the cable. These coil springs are easily overcome by the application of a fairly minor force, causing the winch drum to rotate in the second unwinding direction, thereby extending the cable from the housing unit. This mechanism is similar to that found on an automobile safety belt, where forward movement of the wearer allows the safety belt to extend, and rearward movement of the wearer allows the safety belt to automatically retract. It is also similar to the mechanism that allows a tape measure to be easily pulled from its housing, and then to automatically retract thereinto. 
     In yet another embodiment of the device, active retraction of the cables  14 , 15  is performed by combining the automatic retraction function described above with a one-way rotation locking mechanism. That is, as before, whenever there is slack in the cables  14 , 15  the biasing mechanism  50  retracts the cables  14 , 15 , but in this mode the winch drums  12 , 13  rotate only in the first winding direction. Regardless of any force applied to the cables  14 , 15  in an attempt to extract them from the housing unit  11 , the winch drums  12 , 13  will not rotate in the second unwinding direction. This is accomplished, for example, by having a moveable pin which is engageable with the winch drum, similarly configured to a typical ratchet mechanism. When the pin is disengaged, the winch drums  12 , 13  are free to rotate in either direction, but when engaged the winch drums  12 , 13  rotate only in the first winding direction. Engagement is affected by the remote control unit  30 . While this embodiment provides for a slower retraction process (the wearer has to bring the legs together), it has the advantage of not requiring powered servomotors. And while the wearer can maintain leg separation to prevent retraction, such a posture is not conducive to escape. 
     The retractable leg irons  10  may also provide a means of shocking the wearer of the device. In shock mode, the control unit  18  may send a predetermined amount of electrical current through the cables  14 , 15  and cuffs  16 , 17 , applying a shock to the wearer of the device. The control unit  18  preferably tracks and records the amount of time that a shock is administered to the wearer of the device. In this embodiment, the cables  14 , 15  and cuffs  16 , 17  are made of an electrically conductive material. In the embodiments of the invention where the cuffs  16 , 17  are fixedly attached to the housing units (for example, where multiple housing units  210 , 212  are used), the cable  240  need not be electrically conductive, as the electrical current will flow from each housing unit  210 , 212  directly to the cuffs  16 , 17 . 
     The retractable leg irons  10  may further comprise a remote control  30  having a rechargeable battery and a charging port  42  in communication with the rechargeable battery. See  FIG. 3 . The remote control  30  provides a means for actively retracting the cables  14 , 15  of the retractable leg irons  10 . At the very least, the remote control  30  is capable of switching the mode of the retractable leg irons  10  between the normal operation mode described above and the emergency mode described above. To do this, in one embodiment the remote control provides a transmitter  31  preferably located on a top edge of the remote control  30  and an emergency activation button  33 . In addition to the emergency activation button  33 , the remote control  30  may also provide any of the following buttons and functions: a remote power button  34  (for activating the remote); a shock power button  35  (for enabling the shock feature of the device); an emergency shock button  36  (for activating the shock mode of the device); adjustment control buttons  37  (for adjusting the voltage level of the shock feature); a lock/unlock button for use when the device is not in emergency mode; and/or a reset button  38  (for resetting the shock settings to zero). 
     A more advanced remote control  30  may be provided which further comprises a digital screen  32 . The digital screen  32  may provide additional information about the device such as: the voltage setting for the shock mode, the current mode the device is in, the amount of time a shock was applied, whether the shock mode is enabled or not, or any other relevant information about the system. In yet another embodiment, a single remote control  30  may be programmed to operate several devices. In still another embodiment, the remote control  30  may be represented as an application (“APP”) on a smart phone, tablet, or computer. 
     The device may have other optional features. In one embodiment the housing unit  11  further comprises a plurality of wheels located on the bottom of the housing unit  11 . The wheels prevent the housing unit from dragging on the ground while being worn. In another embodiment, the housing unit  11  further comprises one or more indicator lights, to provide a visual indicator that various features of the device are operational. The one or more indicator lights may be LED lights, they may be of the same or different color, they may remain on as a steady light or as a flashing light. Additionally, an audible indicator may be included on the housing unit  11 , to provide an audible indicator that various features of the device are operational. The audible indicator may be a small speaker that emits a buzz, or a tone, or any other appropriate audible sound. In the preferred embodiment, both the visual indicator and the audible indicator are activated whenever the emergency retraction function of the device is activated; this provides sensory assistance to the location of the wearer of the device. Other optional features are also contemplated. 
     To use the retractable leg irons  10 , each of the cuffs  16 , 17  is placed around a leg of the wearer and then locked, so that the wearer cannot remove the cuffs  16 , 17  without unlocking the cuffs  16 , 17 . One end of each cable  14 , 15  is permanently affixed to the cuffs  16 , 17 . A swivel may be interposed between the end of a cable and a cuff to provide better mobility to the wearer in normal operating mode. The opposite end of each cable  14 , 15  is attached to a winch drum  12 , 13  which is mounted within the housing unit  11 . The operator then sets the device to the normal operating mode using the remote control  30 . In the normal operating mode, the winch drums  12 , 13  are free to rotate and so the wearer is able to move around with little resistance as the cables  14 , 15  freely extend and retract through the apertures  41  on the ends of the housing unit  11 . The cables  14 , 15  freely extend and retract by coiling and uncoiling around the winch drums  12 , 13  which rotate freely in the normal operating mode. 
     In the embodiment using a single cable  140 , each of the cuffs  16 , 17  is placed around a leg of the wearer and then locked, so that the wearer cannot remove the cuffs  16 , 17  without unlocking the cuffs  16 , 17 . One end of the cable  140  is permanently affixed to one cuff A swivel may be interposed between the end of the cable and the cuff to provide better mobility to the wearer in normal operating mode. The opposite end of the cable  140  is attached to a winch drum which is mounted within the housing unit  110 . The other cuff is attached to the housing unit  110 . A swivel may be interposed between the housing unit and the cuff to provide better mobility to the wearer in normal operating mode. The operator then sets the device to the normal operating mode using the remote control  30 . In the normal operating mode, the winch drum is free to rotate and so the wearer is able to move around with little resistance as the cable  140  freely extends and retracts through the aperture in the housing unit  110 . The cable  140  freely extends and retracts by coiling and uncoiling around the winch drum which rotates freely in the normal operating mode. 
     In the embodiment using a single cable  240  and two housing units  210 , 212 , each of the cuffs  16 , 17  is placed around a leg of the wearer and then locked, so that the wearer cannot remove the cuffs  16 , 17  without unlocking the cuffs  16 , 17 . One cuff is attached to the first housing unit  210  and the other cuff is attached to the second housing unit  212 . A swivel may be interposed between each housing unit  210 , 212  and the attached cuff to provide better mobility to the wearer in normal operating mode. One end of the cable  240  is attached to the winch drum located in the first housing unit  210  and the other end of the cable  240  is attached to the winch drum located in the second housing unit  212 . The operator then sets the device to the normal operating mode using the remote control  30 . In the normal operating mode, the winch drums are free to rotate and so the wearer is able to move around with little resistance as the cable  240  freely extends and retracts through the apertures in the housing units  210 , 212 . The cable  240  freely extends and retracts by coiling and uncoiling around the winch drums which rotate freely in the normal operating mode. 
     Should it become necessary to restrict the movement of the wearer, the operator presses the emergency activation button  33 . A signal is sent from the transmitter  31  which is received by the sensor  40 . The sensor  40  communicates the signal to the control unit  18 , which then activates the emergency mode of the device. When the emergency mode is activated an optional indicator light  39  on the remote control  30  may light up and the control unit  18  activates the servomotors  22 , 23  which rotate the winch drums  12 , 13  to retract the cables  14 , 15 . The cables  14 , 15  are retracted until the cuffs  16 , 17  rest against the apertures  41  at the ends of the housing unit  11 . When the cables  14 , 15  are fully retracted the winch drums  12 , 13  are locked into place; the shortened length of the cables  14 , 15  restricts the movement of the wearer&#39;s legs. 
     Alternatively, there may be a need to fix the length of the device without resorting to activating the emergency mode. That is, perhaps a shortened length is desired to partially impede the movement of the wearer. In such a scenario, the cables  14 , 15  are extended only part way out of the housing unit  11 , and then the cables  14 , 15  are locked into place. This can be accomplished by activating the lock function from the remote control unit  30 . No retraction of the cables  14 , 15  takes place when the lock function is initiated, but the winch drums  12 , 13  are locked and no longer able to rotate. Once this function is no longer desired, an unlock instruction is sent by the remote control unit  30  to unlock the winch drums  12 , 13  and place the device into normal operating mode. 
     Should additional means be necessary to stop the wearer of the device, the operator may enable the shock mode by pressing the shock power button  35 . This enables the shock feature of the device so that a high voltage electrical current can be applied to the wearer when needed. Should the shock become necessary, the operator presses the emergency shock button  36 . So long as the emergency shock button  36  is held down an electrical current is administered to the wearer through the cables  14 , 15  and the cuffs  16 , 17 . The remote control  30  tracks the amount of time the emergency shock button  36  is held down and stores the times so that they may be reviewed in the future. 
     In an alternate embodiment, the remote control  30  provides a digital display  32 . The digital display  32  shows relevant information about the device which may include the current voltage level for the shock mode, the most recent time data for the shock mode usage, whether the shock mode is enabled, or any other relevant information. The operator may adjust the voltage level of the electrical current used in shock mode by using the adjustment control buttons  37 . The operator may reset the shock mode settings by pressing the reset button  38 . When the reset button  38  is pressed the voltage level returns to the lowest setting and all stored time data is erased. 
     Once the wearer has been restrained and is ready to be transported again the operator can return the retractable leg irons  10  to the normal operating mode by holding the emergency activation button  33  for a predetermined amount of time. When the emergency activation button  33  is held long enough the indicator light  39  flashes twice and the transmitter  31  sends a signal to the sensor  40 . The sensor  40  then communicates the signal to the control unit  18  which deactivates the servomotors  23 , 24  and unlocks the winch drums  12 , 13 . The winch drums  12 , 13  are then free to rotate again, which allows the cables  14 , 15  to freely extend and retract. 
     The housing unit  11  and battery door  21  are preferably manufactured from a rigid, durable, and lightweight material such as magnesium alloy. The cables  14 , 15  and cuffs  16 , 17  are preferably manufactured from a durable material with high tensile strength such as galvanized steel. The cables  14 , 15  may be wire cables, flexible sheet metal straps, coated or uncoated with fabric or plastic coverings, or the like. The sensor window  20  is preferably manufactured from a transparent durable material such as bullet proof glass. 
     Components, component sizes, and materials listed above are preferable, but artisans will recognize that alternate components and materials could be selected without altering the scope of the invention. 
     While the foregoing written description of the invention enables one of ordinary skill to make and use what is presently considered to be the best mode thereof, those of ordinary skill in the art will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should, therefore, not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.

Summary:
A remote controlled retractable leg iron device provides a restraint device which can be used by police or any other authority to maintain control of persons while in transport. The device is remote controlled so an operator can control the wearer from a distance. The cuffs are secured to the legs of the wearer and are attached to the housing unit by cables which coil around winch drums within the housing unit. The winch drums rotate freely in a normal operation mode so that the wearer can walk or move with little resistance. In an emergency mode, the device retracts the wire cables into the housing unit so that the wearer&#39;s legs are restrained tightly together—removing the lack of resistance and thus stopping the wearer&#39;s motion. The emergency mode is activated using the remote control.