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This is a continuation-in-part of U.S. application Ser. No. 10/1766,235 filed Jan. 28, 2004, now U.S. Pat. No. 6,978,644, which is a continuation-in-part of application Ser. No. 10/394,668, filed Mar. 21, 2003, now U.S. Pat. No. 6,684,666 issued Feb. 3, 2004, which is a continuation-in-part of application Ser. No. 10/091,272, filed Mar. 5, 2002, now U.S. Pat. No. 6,568,224 issued May 27, 2003. 

   BACKGROUND OF THE INVENTION 
   1. Technical Field of the Invention. 
   This invention broadly relates to locking devices. The invention further relates to locking devices useful to physically restrain the movement by an individual of his or her arms and/or legs. This invention more particularly relates to mechanical restraining devices referred to in the art as “handcuffs.” This invention specifically relates to an operating and a locking mechanism for a handcuff. 
   2. Description of the Prior Art and Problems Solved. 
   It is known in the art that a handcuff is an apparatus which is ordinarily placed around the wrist or ankle of an individual. The apparatus is usually directly connected to another such device by a bridge, such as a chain, a link, or a bar, to thereby form a combination of such devices. The combination is referred to in the art as “handcuffs” or as a “set of handcuffs.” 
   It is known in the art to place handcuffs upon an individual to render such individual physically ineffective or powerless. Accordingly, handcuffs can be employed in the field of law enforcement for the purpose of physically restraining an individual from escape and/or to prevent such restrained individual from injuring himself and/or some other person, such as a police officer. It is apparent that a handcuff, or handcuffs, which can be opened and removed by the person being restrained, or by any other unauthorized person, either by force or by device defeats the purpose of the handcuffs. 
   A handcuff described in prior work of the applicant herein contains mechanisms which function to permit the apparatus to open and to close and also function to prevent the apparatus from opening. The first function is referred to as the “operating mechanism.” The second function is referred to as the “locking mechanism.” 
   An example of a handcuff previously described by applicant is an apparatus comprised of a combination of at least two, and sometimes three, planar, substantially parallel, plates and a movable arm. The plates and movable arm cooperate to produce a ring defined as a “restraining space” which can be opened and closed. It is to be understood that the wrist or ankle of the individual to be restrained is placed and confined in the restraining space. 
   The combination of plates is a sandwich structure comprised of two, aligned, exterior plates which cooperate to form a stationary arm and an enclosed interior space. The enclosed interior space is referred to as the “machinery space.” The machinery space can sometimes be further defined by holes and cavities formed in a third plate positioned between the two exterior plates. The third plate separates the exterior plates and provides spaces in which the operating and locking mechanisms are positioned. 
   Each exterior plate is ordinarily a unitary body comprised of a first section, referred to as a “cheek plate,” and a second section, referred to as a “plate arm.” The cheek plates serve as the top and bottom covers of the machinery space and as a base to support the operating and locking mechanisms positioned in the machinery space. The plate arms combine to form the mentioned stationary arm. 
   Each plate arm, which extends beyond the cheek plate to form one side of the stationary arm, is a rigid, curvilinear, i.e., a “C-shaped,” member which terminates at an end adapted for hinged attachment to the movable arm. The stationary arm, formed by the combination of the aligned, curvilinear, plate arms, is referred to as such to distinguish the combination of plate arms from the movable arm of the handcuff. The combination of the terminal ends of each plate arm is referred to as the hinge end of the stationary arm. 
   The movable arm of a handcuff, which is referred to as a swing arm, is also a rigid, curvilinear member having a pivot end and a free end. The pivot end of the swing arm is positioned between the terminal ends of each plate arm and is rotatably connected to the hinge end of the stationary arm. The free end of the swing arm is equipped with teeth adapted to engage, that is, contact and intermesh with, opposing teeth mounted within the machinery space. 
   Accordingly, in operation, the pivot end of the swing arm and the hinge end of the stationary arm cooperate to permit the free end of the swing arm to rotate into at least a portion of the machinery space wherein the teeth on the free end of the swing arm engage teeth mounted within the machinery space to thereby form the restraining space. 
   In handcuffs known in the art prior to the work of applicant, the restraining space is opened by causing the teeth of the swing arm to disengage from the teeth in the machinery space followed by rotating the swing arm out of the machinery space. Thus, the operating mechanism of handcuffs known in the art prior to the disclosure of U.S. Pat. No. 6,568,224 features a substantially linear member enclosed in the machinery space having a plurality of teeth mounted on one side thereof which are adapted to engage teeth on the swing arm. The linear member is hinged at one end and biased to urge the teeth on the linear member into engagement with the teeth on the swing arm. The mechanism has been characterized as a hinged pawl situated within the machinery space of the handcuff. The swing arm must enter the machinery space to form, i.e. close, the restraining space. Accordingly, the swing arm is rotated into the machinery space with force sufficient to overcome the resistance of the biasing source to cause the pawl to rotate about the hinge. The result of this action is to raise the teeth on the pawl out of engagement with the teeth on the swing arm. The operating mechanism employs a reciprocating action wherein teeth on the pawl and teeth on the swing arm are continually alternating between an engaged and a disengaged condition as the swing arm is rotated into the machinery space. This operating mechanism is referred to as the ratchet and pawl mechanism. 
   U.S. Pat. No. 6,568,224, a parent of the present invention provides a handcuff having an operating mechanism which is at all times in full contact and intermeshed with teeth on the swing arm when the handcuff is being either opened or closed, and it also provides a handcuff having a locking mechanism which can permit or prevent movement of the operating mechanism. 
   The &#39;224 patent discloses a handcuff comprised of a housing having an operating and a locking mechanism enclosed therein. The housing is comprised of at least two, substantially identically shaped, opposed, substantially parallel plates and a swing arm. Each plate is a unitary body having an inside surface, an outside surface, an arm side and an open side, and each plate is divided into a first section, referred to as a “cheek plate,” and a second section referred to as a “plate arm.” A plate arm is a narrow, elongated, curvilinear part of the plate which extends in an arc from the arm side of the plate to a terminal end on the open side of the plate. The plates are spaced apart to provide a machinery space between the opposed inside surfaces of each cheek plate and a curvilinear stationary arm defined by the spaced, opposed plate arms. The space between the terminal ends of the plate arms is referred to as the hinge end of the stationary arm. 
   The swing arm, like the stationary arm, is also a narrow, elongated curvilinear body having a pivot end and a free end. The pivot end of the swing arm is positioned between the terminal ends of the plate arms and rotatably connected to the hinge end of the stationary arm. The swing arm extends in an arc toward the open side of each plate from the hinge end of the stationary arm to the free end of the swing arm. The free end of the swing arm is equipped with teeth adapted to engage, that is, contact and intermesh with, opposing teeth mounted within the machinery space. 
   The swing arm, the stationary arm, and the inner edges of the opposed cheek plates cooperate to form the restraining space of the handcuff when the free end of the swing arm is rotated into and engaged with teeth mounted in the machinery space. 
   The operating mechanism of the handcuff disclosed in the &#39;224 patent is housed in the machinery space between the opposed cheek plates. The operating mechanism can be a single toothed wheel, that is, a gear, whose teeth engage the teeth mounted on the swing arm. The operating mechanism can be comprised of two gears, each of whose teeth can simultaneously engage the teeth mounted on the swing arm. The operating mechanism can be comprised of an array of three intermeshing gears having two gears, referred to as “working gears,” whose teeth simultaneously engage the teeth mounted on the swing arm, and a third gear, referred to as an “idler gear,” whose teeth are continually engaged with the teeth on at least one working gear and can be continually engaged with the teeth on the two working gears. When the handcuff is being opened or closed, that is, when the restraining space is being opened or closed, teeth mounted on the swing arm are always in contact with teeth on at least one of the working gears. Thus, gear teeth engage teeth of the swing arm when the swing arm is in the closed position and not moving, when the swing arm is being rotated toward the open side of the plates to place the handcuff into the closed position and when the swing arm is being rotated away from the open side of the plates to place the handcuff in an open position. 
   Any working gear of the operating mechanism having teeth engaged with teeth on the swing arm must rotate to enable any movement of the swing arm. Accordingly, the handcuff of the &#39;224 patent also provides a multi-function locking mechanism which controls the rotation of the gears. The locking mechanism is housed in the machinery space between the opposed cheek plates in a location separate from the operating mechanism. In a first locking position referred to as the “closing position,” the locking mechanism is positioned to permit rotation of the gears in one direction to permit closing rotation of the swing arm, and to prevent rotation of the gears in the opposite direction to prevent opening rotation of the swing arm. In a second locking position referred to as the “locked position,” the locking mechanism is positioned to prevent any rotation of the gears in any direction to prevent any rotation of the swing arm in any direction. In a third locking position referred to as the “free position,” the locking mechanism is positioned to permit rotation of the gears in any direction to permit rotation of the swing arm in any direction. 
   The operating mechanism of the handcuff of the &#39;224 patent is broadly comprised of a first working gear and a swing arm. The first working gear is rotatably mounted on a first gear axle which is perpendicularly attached to a fixed planar base, and the swing arm is rotatably mounted on a swing arm axle which is also perpendicularly attached to the planar base. 
   The operating mechanism of the handcuff of the &#39;224 patent can further include a control pin comprising a linear rod slidably mounted on, and parallel to, the fixed planar base in a position opposed to the first working gear and preferably perpendicular to the first gear axle. The rod has a proximal end, a distal end and a biasing means, such as spring, abutting the distal end of the rod to urge the proximal end of the rod into contact with the teeth on the first working gear. The proximal end of the rod is adapted to contact the teeth on the first working gear to permit rotation of the first working gear around the first axle in one rotational direction while preventing rotation of the first working gear around the first axle in the opposite rotational direction. 
   The operating mechanism of the handcuff of the &#39;224 patent cooperates with a locking mechanism which converts rotational motion to linear motion. The locking mechanism is comprised of a cam in operable combination with a cam follower, referred to as a cam lever, which is perpendicularly and rigidly attached to the mentioned linear rod of the control pin at a point intermediate the proximal end and the distal end of the linear rod. 
   The cam of the handcuff of the &#39;224 patent is a plate having a hole in one end, referred to as the axle end, and a forked end linearly spaced apart from the axle end. The cam is referred to as a yoke. The axle end of the yoke is closed and rotatably mounted on a yoke axle. The forked end of the yoke is open having a first leg on one side of the opening and a second leg on the opposite side of the opening side. The second leg is spaced apart from the first leg. 
   The yoke axle is perpendicularly fixed to the planar base. The axle end of the yoke is rotatably mounted on the yoke axle so that the cam lever on the control pin is situated between the first leg and the second leg of the forked end of the yoke. The yoke rotates around the yoke axle in a plane parallel to the planar base. Rotation of the yoke around the yoke axle in one rotational direction causes contact between the cam lever and the inside surface of the first leg to thereby linearly urge the rod against the biasing means at the distal end of the rod. Rotation of the yoke around the yoke axle in the opposite rotational direction causes contact between the cam lever and the inside surface of the second leg to thereby linearly urge the proximal end of the rod against the teeth of the first working gear. 
   The locking mechanism of the handcuff of the &#39;224 patent can be further comprised of a means for rotating the yoke on the yoke axle and detent means for maintaining the position of the yoke with respect to the cam lever in either the closing position or the locked position. 
   U.S. Pat. No. 6,568,224 discloses an operating mechanism featuring a control pin which directly contacts a working gear. Also illustrated is an embodiment featuring an array of three intermeshing gears consisting of two working gears and one idler gear. U.S. Pat. No. 6,684,666, a parent of the present application, discloses an operating mechanism featuring a control pin which directly contacts the idler gear. 
   The cam employed in the disclosures of the &#39;224 patent and the &#39;666 patent is an oval plate in the shape of a yoke having a closed end and an open end. The oval plate is positioned in a cavity of the machinery space. A key is employed to rotate the plate around the yoke axle to position the control pin in a desired location. The yoke axle is not placed in the center of the cavity. Accordingly, the eccentric position of the yoke axle requires a cavity much larger in size than the cam to enable rotational movement of the cam. 
   U.S. application Ser. No. 10/766,235, a parent of the present invention, discloses a handcuff having an electro-mechanical locking mechanism which can be remotely operated with an electronic key to control the rotation of a gear around a gear axle, i.e., a hub. The handcuff of application Ser. No. 10/766,235 comprises a bi-directional solenoid, having an associated power source and a UHF receiver, a cam, and an accutation arm. The cam is moved by the bi-directional solenoid. The solenoid and cam, in combination with a UHF RF transmitter, permit the handcuff to be locked and unlocked electronically. The use of a mechanical key is not required, but may be employed. 
   The cam and actuation arm operate in combination to linearly move a control rod which is adapted to contact the teeth of the gear. 
   The cam is a flat, substantially circular, plate which is rotatably attached to an axle. The axle, referred to as the cam axle, is perpendicularly fixed to a planar base. The cam is adapted to rotate around the cam axle in a plane which is parallel to the base. The gear hub, mentioned above, is, preferably, perpendicularly fixed to the same planar base as the cam axle. The gear is adapted to rotate around the hub in a plane which is parallel to the base. The circular cam is positioned in a circular cavity in the machine space. The cam axle is substantially centered in the circular cavity. 
   The actuation arm is comprised of a cylinder and a housing. The hollow interior of the housing contains at least one coil of the type adapted to conduct an electric current. The cylinder includes a plunger adapted to longitudinally slide within the coils in the hollow interior of the housing. The plunger slides within the coils upon passage of an electric current through the coils. Linear movement of the plunger operates to cause the cam to rotate. 
   THE INVENTION 
   This invention provides a handcuff having at least one gear, a swing arm, a control rod, and a rod cam. The teeth on the gear remain constantly intermeshed with the teeth on the swing arm while the handcuff is in the closed position or is being opened or is being closed. 
   The gear is rotatably attached to an axle, which is perpendicularly affixed to a planar base. The gear rotates around the axle in a plane parallel to the planar base in response to rotation of the swing arm, which is also rotatably attached to the planar base. 
   The control rod is slidably mounted on the planar base, and is adapted to control the rotation of the gear. In this regard, the control rod is equipped with a tip end which, in one mode, can be positioned to contact the gear to enable the gear to rotate in the closing direction, but not in the opening direction. In another mode, the tip end of the rod can be positioned to avoid contact with the gear to enable the gear to rotate in the closing direction and in the opening direction. In still another mode, the tip can be positioned to contact the gear to prevent the gear from rotating in any direction. 
   The rod cam controls the position of the tip end of the control rod relative to the gear. The cam is confined to, and rotates within, a cam space which abuts the planar base. The cam rotates in a plane parallel to the planar base, but it does not rotate around an axle attached to the planar base. 
   The rod cam is comprised of a cam plate and a cam shaft. The cam plate is substantially circular in shape; it includes a top surface, a bottom surface and a set of shoulders. Rotation of the cam causes the shoulders to contact and slide the control rod on the planar base to position the tip end of the control rod with respect to the gear. The cam shaft perpendicularly extends from the top surface of the cam plate and can perpendicularly extend from the top and bottom surface of the cam plate. The cam plate and cam shaft interact to cause the cam plate to rotate within the cam space upon rotation of the cam shaft. 
   The handcuff can have any number of gears, but it must have at least one gear. In an embodiment having a single gear, the single gear is a working gear; that is, the teeth of the working gear intermesh with the teeth of the swing arm. The handcuff can have two working gears. The handcuff can have a single working gear and an idler gear, wherein the teeth of the idler gear intermesh with the teeth of the working gear, but not with the teeth of the swing arm. In another embodiment, the handcuff can have two working gears and a single idler gear. The control rod can contact a working gear or an idler gear to control the rotation of all gears. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a plan view of a set of handcuffs. The view of the left handcuff shows the outer surface of the top cheek plate and plate arm and a partial view of the swing arm. The view of the right handcuff does not show the top cheek plate in order to expose the machinery space and the contents thereof. The swing arm engaged with a gear in the machinery space and a partial view of the inner surface of the bottom plate arm is also shown. 
       FIG. 2  is a section view of the left handcuff of  FIG. 1  taken in the direction of cut line  2 — 2 . 
       FIG. 3  is an enlarged view of the right handcuff of  FIG. 1  lying within circle  3 .  FIG. 3  shows the machinery space, and a partial view of the swing arm. 
       FIG. 4  is a plan view of the machinery block of  FIG. 3  situated between the inner surfaces of the top cheek plate and the bottom cheek plate of the right handcuff. 
       FIG. 5  is a section view of the machinery block shown in  FIG. 4  taken in the direction of cut line  5 — 5 . 
       FIG. 6  is a section view of the machinery block shown in  FIG. 4  taken in the direction of cut line  6 — 6 . 
       FIG. 7  is a plan view of the rod cam. 
       FIG. 8  is a section view of the rod cam shown in  FIG. 7  taken in the direction of cut line  8 — 8 . 
       FIG. 9  is an enlarged view of the left handcuff of  FIG. 1  lying within circle  9  showing the keyhole element. 
       FIG. 9   a  is a plan view of an alternative to the key hole element shown in  FIG. 9 . 
       FIG. 10  is a side view of a key employed to rotate the rod cam shown in  FIG. 7 . 
       FIG. 11  is a section view of the key shown in  FIG. 10  taken in the direction of cut line  11 — 11 . 
       FIG. 12  is the bottom view of the key shown in  FIG. 10 . 
       FIG. 13  is the top view of the key shown in  FIG. 10 . 
       FIG. 14  is an enlarged view of the machinery space of an embodiment of a handcuff having three gears. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to  FIGS. 1 ,  2  and  3 , a set of handcuffs is shown consisting of left handcuff  1  and right handcuff  2 . Handcuff  1  and handcuff  2  are identical, accordingly, unless specifically stated to the contrary, a reference numeral made with reference to one of the two handcuffs applies to the other. 
   Top cheek plate  10  and plate arm  11  of right handcuff  2  are not shown in order to reveal machinery space  3  consisting of machinery housing  4  which contains rod cam  5 , control rod  6  and working gear  7 . The view of right handcuff  2  also shows the inside surface of plate arm  8  and swing arm  9 . 
   The view of the left handcuff  1  shows the outside surface of top cheek plate  10 , plate arm  11  and a partial view of swing arm  9 .  FIG. 2 , a section view of left handcuff  1 , shows top cheek plate  10 , bottom cheek plate  12 , machinery housing  4 , gear axle  13 , rivets  21  and  22  and rod cam  5  consisting of cam plate  15  and cam shaft  16 .  FIG. 2  also shows dowel  17 , detent ball  18 , detent spring  19 , and plug  20 . 
   Machinery housing  4  is located between, and rigidly connected to, top cheek plate  10  and bottom cheek plate  12  by rivets  14 ,  21  and  22 . 
   Left handcuff  1  and right handcuff  2  are connected by links  23  and  24 . Links  23  and  24  are fastened to the cuffs by pin  25  which passes through holes drilled (not show) in links  23  and  24 . As shown in  FIG. 4 , pin  25  is contained in hole  26  drilled in machinery housing  4 . Link  23  is positioned in open slot  23   a  cut in machinery housing  4  and aligned slots (not shown) cut in cheek plates  10  and  12 . Link  24  is positioned in open slot  24   a  cut in machinery housing  4  and slots (not shown) cut in cheek plates  10  and  12 . 
   Hinge end  27  of swing arm  9  is rotatably connected to end  28  of plate arm  8  and end  29  of plate arm  11  by pin  30 . 
   Referring now to  FIGS. 4 ,  5  and  6 , machinery housing  4  is comprised of cam space  31 , control rod cavity  32  and gear cavity  33 . Machinery housing  4  also includes dowel holes  34 ,  35 ,  36  and  37 , and drilled holes  38 ,  39 ,  40 ,  41  and  42 . 
   Cam space  31  is substantially circular in shape. It completely penetrates the entire thickness of machinery housing  4  to enable unobstructed access between the inside surface of top cheek plate  10  and bottom cheek plate  12 . As seen in  FIG. 4 , dowel holes  34 ,  35 ,  36  and  37  completely penetrate the entire thickness of machinery housing  4  and are spaced around the perimeter of cam space  31 . Holes  34 ,  35  and  36  are all positioned on one of the semicircular sides of cam space  31  and hole  37  is placed on the other. The radius of each dowel hole is substantially less than the radius of cam space  31 . In addition, the distance from center  31   a  of cam space  31  to the center of any particular dowel hole is less than the sum of the radius of cam space  31  and the radius of the dowel hole. As a result, the perimeter of each of dowel holes  34 ,  35 ,  36  and  37  intersects the perimeter of cam space  31 . It is preferred that the distance from cam space to  31  to the center of each of dowel holes  34 ,  35 ,  36  and  37  is identical and that the radius of each dowel hole is the same. Furthermore, it is preferred that the center of each dowel hole is spaced at least about 45 degrees apart from the immediately adjacent dowel hole. Thus, as seen in  FIG. 4 , dowel hole  35  is separated from dowel hole  34  by about 45 degrees and from dowel hole  36  by about 45 degrees. Dowel hole  36  is separated from dowel hole  37  by about 90 degrees, and dowel hole  34  is separated from dowel hole  37  by about 180 degrees. 
   Control rod cavity  32  intersects cam space  31  and gear cavity  33 . Cavity  32  is comprised of two intersecting linear slots  43  and  44 . Slots  43  and  44  do not penetrate the entire thickness of machinery housing  4 . Accordingly, the top surface of machinery housing  4  is penetrated, but the bottom surface is not, thereby forming shelf  45  under each of slots  43  and  44 . Slot  43  intersects gear cavity  33 , wherein edge  46  of slot  43  is substantially perpendicular to center  33   a  of gear cavity  33 . Slot  44  intersects cam space  31  at a position intermediate dowel hole  36  and dowel hole  37 , wherein the linear axis of slot  44  is substantially perpendicular to center  31   a  of space  31 . 
   Gear cavity  33  comprises a first portion having a single curvilinear edge  47  and a second portion having parallel linear edges  48  and  49 . Curvilinear edge  47  is substantially a semicircle whose center of rotation is center  33   a  of cavity  33 . Edge  47  terminates at two points. In one instance edge  47  terminates and edge  49  begins at the point of intersection of edge  46 . In the second instance edge  47  terminates and edge  48  begins at the point of intersection of the extension of edge  46  through center  33   a  of cavity  31 . Each of parallel edges  48  and  49  terminates at lower edge  50  of machinery housing  4 . It is shown in  FIG. 4  that slot  44  intersects cam space  31  at edge  31   b  of cam space  31 . 
   Gear cavity  33  does not penetrate the entire thickness of machinery housing  4 . The top surface of machinery housing  4  is penetrated, but the bottom surface is not, thereby forming shelf  51  under cavity  33 . Center  33   a  of cavity  31  is also the center of gear axle hole  39  which penetrates shelf  51 . 
   Closed linear hole  38  begins at open end  38   a , penetrates the edge of machinery housing  4  at gear cavity  33 , and proceeds in a direction perpendicular to center  31   a  of cam space  31 . Hole  38  passes through dowel hole  35 , continues at the opposite perimeter edge of machinery housing  4  and terminates at closed end  38   b  without penetrating the opposite edge of machinery housing  4 . Linear hole  38  lies between the top and bottom surfaces of machinery housing  4 . 
   Closed linear hole  26  begins at open end  26   a  and continues to closed end  28   b . Hole  26  is perpendicular to slots  23   a  and  24   a.    
   Refer to  FIGS. 3–8  and note that rod cam  5  is rotatably positioned in cam space  31 ; control rod  6  is positioned in control rod cavity  32 ; and working gear  7  is positioned in gear cavity  33 . Control rod  6  is comprised of linear pin  52  and cam lever  53 . Linear pin  52  includes distal end  54  and proximal end  55 . Cam lever  53  is a linear element which is perpendicularly and rigidly attached to pin  52  intermediate distal end  54  and proximal end  55 . Cam lever  53  includes free side  53   a , locked side  53   b  and top side  53   c.    
   Control rod  6  is slidably positioned in rod cavity  32  so that distal end  54  extends into closed end  43   a  of slot  43 , top side  53   c  of lever  53  extends into cam space  31 , and proximal end  55  is enabled to extend into gear cavity  33 . Biasing spring  56  is placed in closed end  43   a  of slot  43  intermediate distal end  54  of pin  52  and the terminus of slot  43 . Spring  56  functions to urge proximal end  55  into cam space  31 . Control rod  6  is slidably supported in machinery housing  4  by shelf  45 . 
   As previously mentioned, rod cam  5  is substantially circular in shape and is comprised of cam plate  15  and cam shaft  16 . Cam plate  15  is comprised of cam lever slot  57 , locking detent  58 , closing detent  59 , ramp  65  and curve  66 . Cam plate  15  has a planar top surface  60  and a planar bottom surface  61 . 
   Cam lever slot  57 , which consists of free side  62 , locked side  63  and bottom  64 , is a substantially rectangular opening formed in the edge of plate  15 . Locking detent  58  and closing detent  59  are concavities formed in the edge of plate  15 , wherein detent  59  is positioned between locked side  63  of slot  57  and detent  58 . Ramp  65  is a convex surface joining the edge of plate  15  and detent  59 . Curve  66  is a convex surface joining the edge of plate  15  and locked side  63  of slot  57 . 
   The diameter of cam plate  15  is less than the diameter of cam space  31  to thereby enable plate  15  to be placed and rotate in space  31 . Dowels  17 ,  68 ,  69  and  70  are positioned to substantially maintain center  15   a  of cam plate  15  in alignment with center  31   a  of cam space  31 , and to minimize friction between the perimeter of cam plate  15  and the edge of cam space  31  as cam plate  15  rotates in cam space  31 . 
   Cam shaft  16  is a rigid linear element which is perpendicular to at least one planar surface of plate  15 , such as top surface  60  of cam plate  15 . Shaft  16  is shaped to prevent rotation of plate  15  around shaft  16  and to cause plate  15  to rotate upon rotation of shaft  16 . In one embodiment, shaft  16  is rigidly attached to cam plate  15 . As shown in  FIGS. 2 and 9 , shaft  16  extends through key hole  67  bored in cheek plates  10  and  12 . 
   As shown in  FIGS. 7 and 8 , cam shaft  16  has an irregular horizontal cross section. More specifically, the horizontal cross section of shaft  16  is triangular in shape, wherein the vertices of the triangle are curved lobes. Shaft  16  is fixed in a hole drilled entirely through cam plate  15 . The shape of the hole in plate  15  is identical to the horizontal cross section of shaft  16 . Accordingly, shaft  16  does not rotate in the hole formed in plate  15 . As shown in  FIG. 2 , shaft  16  perpendicularly extends beyond top surface  60  and bottom surface  61  of plate  15  through key hole  67  drilled in cheek plate  10  and a hole drilled in cheek plate  12 . The top and bottom surfaces of shaft  16  are, preferably, in alignment with the upper surfaces of cheek plates  10  and  12 , respectively. 
   As shown in  FIGS. 3 and 4 , dowels  17 ,  68 ,  69  and  70  are positioned in dowel holes  35 ,  34 ,  36  and  37 , respectively. As shown in  FIG. 2 , detent spring  19  is placed in closed end  38   b  of drilled hole  38  and detent ball  18  is positioned in hole  38  intermediate detent spring  19  and cam space  31 . Plug  20  is positioned in the open end of hole  38  and operates to close the open end of hole  38  and to maintain dowel  17  in hole  35 . 
   An arcuate portion of each one of dowels  17 ,  68 ,  69  and  70  extends into cam space  31 . The height of each dowel is equal to the thickness of machinery housing  4 . 
   Detent spring  19  operates to force detent ball  18  into cam space  31  against the edge of cam plate  15 . The diameter of detent ball  18  is less than the thickness of machinery housing  4  and is sized to enable detent ball  18  to slide in and out of hole  38 . 
   Dowels  17 ,  68 ,  69  and  70  and detent ball  18  are in constant contact with the edge of cam plate  15 . 
   As mentioned, rod cam  5  is positioned in cam space  31  wherein it is adapted to rotate in a plane parallel to cheek plates  10  and  12 . In this regard, cam  5  is positioned in space  31  to enable cam lever  53  to extend into cam slot  57  so that free side  53   a  of lever  53  is adjacent to free side  62  of slot  57 , locked side  53   b  of lever  53  is adjacent to locked side  63  of slot  57  and top side  53   c  of lever  53  does not contact bottom  64  of slot  57 . 
   The handcuff, as shown in  FIG. 3 , is in the closing position. As shown in  FIG. 3 , the edge of rod cam  5  is in tangential contact with dowels  17 ,  68 ,  69  and  70 . Detent ball  18  is pushed into closing detent  59  by spring  19 , and free side  53   a  of lever  53  is in contact with free side  62  of slot  57 . Dowels  17 ,  68 ,  69  and  70  and detent ball  18  cooperate to substantially maintain center  15   a  of cam plate  15  in alignment with center  31   a  of cam space  31 . 
   Working gear  7  is positioned and supported on shelf  51  under cavity  33  and is rotatably mounted on axle  13  which passes through hole  39  and is perpendicularly affixed to cheek plates  10  and  12 . As shown in  FIG. 3 , the teeth of gear  7  interact with proximal end  55  of pin  52 . Proximal end  55  is bevel-shaped to permit gear  7  to turn in the counter clockwise direction (the closing direction), but not in the clockwise direction (the opening direction). Gear  7  rotates around axle  13  in plane parallel to cheek plates  10  and  12 . 
     FIG. 9  is a partial view of the top surface of cheek plate  10  showing upper surface  72  of cam shaft  16  positioned substantially in the center of key hole  67  drilled through cheek plate  10 . As shown in  FIG. 2 , upper surface  72  of cam shaft  16  is in alignment with the top surface of cheek plate  10 . An identical view, not shown, and description could be made of the relationship between cam shaft  16  and cheek plate  12 . Key hole  67  enables an individual to rotate cam  5  by use of an appropriate device such as the key shown in  FIGS. 10–13 . 
   Key hole  67  is substantially circular, but the edge of key hole  67  can be smooth or irregular in shape. For example, an irregular edge can assume a saw-tooth shape, as illustrated in hole  67  of  FIG. 9 , or it can assume a shape having pockets or divots, as illustrated in hole  68  of  FIG. 9   a . Thus, continuous saw-teeth  70  are shown on the edge of hole  67 , and spaced pockets  71  are shown on the edge of hole  68 . An annulus space is formed between the edge of hole  67  and cam shaft  16 . The top surface  60  and bottom surface  61  of cam plate  15  can be accessed by way of the annulus space. 
   It is believed that the irregular shape of the edge of key hole  67  will operate to prevent rotation of cam  5  with a device having a deformable surface. For example, a cylinder constructed of deformable plastic which can be softened, such as the barrel of a ball point pen, can be forced into a key hole of a cheek plate and over the shaft. The softened deformable material not only conforms to the shape of the shaft, but also conforms to the shape of the edge of the key hole. If the shape of the edge of the key is smooth, then the deformable material, upon hardening, can be used to rotate the cam, assuming that the deformed cylinder does not break. If the shape of the edge of the key hole is irregular, then the deformable material, upon hardening, cannot operate to rotate the cam in the opening direction, in the case of the saw-tooth edge, or in any direction, in the case of the pocket edge. 
   Key  73  for rotating cam  5  is shown in  FIGS. 10 ,  11 ,  12  and  13 . Key  73  is an article consisting of barrel  74  and handle  75 . Barrel  74  is a solid circular cylinder having an operating end  76  and a handle end  77 . The diameter of barrel  74  is less than the diameter of key hole  67 . Closed axial hole  78  is formed in the end of operating end  76  to a depth at least equal to the distance between upper surface  72  of cam shaft  16  and top surface  60  cam plate  15 . Axial hole  78  is shaped to slidably receive cam shaft  16 . Accordingly hole  78  is triangular in shape, wherein the vertices of the triangle are curved lobes. The shape of hole  78  is identical to the horizontal cross section of shaft  16 . Accordingly, barrel  74  does not rotate around shaft  16 . Rotation of barrel  74  produces identical rotation of cam  5 . 
   A longitudinal notch, not shown, is cut in handle end  77  of barrel  74 . The notch is parallel to the longitudinal axis of barrel  74 . The width of the notch is less than the diameter of barrel  74 , but it is sufficiently wide to slidably receive handle  75 . It is not required that handle  75  be rigidly fixed in the notch, but it must be sufficiently retained in the notch to enable rotational forces applied to handle  75  to be transferred to cam  5  by barrel  74 . 
   OPERATION OF INVENTION 
   The operation of the handcuff of this invention involves placing rod cam  5  in three different positions—the closing position, the locked position and the opening position.  FIGS. 1 and 3  show handcuff  2  in the closing position. 
   In the closing position: the bevel-shaped proximal end  55  of control pin  52  extends into gear cavity  33 , wherein the slanted side of end  55  contacts teeth  79  of gear  7  which intermesh with teeth  80  of swing arm  9 ; control pin  52  is urged into cavity  33  by linear force exerted against distal end  54  of pin  52  by biasing spring  56 ; rod cam  5  is oriented in cavity  31 , so that detent ball  18  is positioned in closing detent  59 , and held therein by linear force exerted by biasing spring  19  against ball  18 ; and cam lever  53  of control rod  6  extends into cam lever slot  57 , wherein free side  62  of slot  57  is contacted by free side  53   a  of cam lever  53 . 
   In the closing position, rotation of cam  5  in cavity  31  is prevented by detent ball  18  in detent  59 ; rotation of swing arm  9  in the closing direction (clockwise) is enabled because gear  7  can rotate in the closing direction (counter clockwise), but rotation of swing arm  9  in the opening direction (counter clockwise) is prevented because gear  7  cannot rotate in the opening direction (clockwise). In this regard, when swing arm  9  is urged to rotate in the closing direction which, in consequence, urges gear  7  to rotate in the closing direction, linear force thus generated by contact between teeth  79  of gear  7  and the slanted side end  55  causes pin  52  to compress biasing spring  56  by an amount sufficient to permit gear  7  to rotate until a tooth  79  passes the slanted side. In contrast, when swing arm  9  is urged to rotate in the opening direction which, in consequence, urges gear  7  to rotate in the opening direction, no linear force is generated by contact between teeth  79  of gear  7  and the flat side end  55 , accordingly, pin  52  does not compress biasing spring  56  to thereby prevent rotation of gear  7  and swing arm  9 . 
   In the locked position: the bevel-shaped proximal end  55  of control pin  52  extends into gear cavity  33  wherein the slanted side of end  55  contacts teeth  79  of gear  7  which intermesh with teeth  80  of swing arm  9 ; control pin  52  is urged into cavity  33  by linear force exerted against distal end  54  of pin  52  by biasing spring  56 ; rod cam  5  is oriented in cavity  31 , so that detent ball  18  is positioned in locking detent  58  and held therein by linear force exerted by biasing spring  19  against ball  18 ; and cam lever  53  of control rod  6  extends into cam lever slot  57 , wherein locked side  63  of slot  57  is contacted by locked side  53   b  of cam lever  53 . 
   In the locked position, rotation of cam  5  in cavity  31  is prevented by detent ball  18  in detent  59 ; rotation of swing arm  9  in any direction is prevented because gear  7  cannot rotate in any direction. In this regard, when swing arm  9  is urged to rotate in the closing direction which, in consequence, urges gear  7  to rotate in the closing direction, linear force thus generated by contact between teeth  79  of gear  7  and the slanted side of end  55  cannot cause pin  52  to compress biasing spring  56  because movement of pin  52  against spring  56  is prevented by contact between lever  53  and locked side  63  of slot  57 . And as previously explained, when swing arm  9  is urged to rotate in the opening direction which, in consequence, urges gear  7  to rotate in the opening direction, no linear force is generated by contact between teeth  79  of gear  7  and the flat side end  55 , accordingly, pin  52  does not compress biasing spring  56  to thereby prevent rotation of gear  7  and swing arm  9 . 
   In the opening position, which is sometimes referred to as the free position: control pin  52  does not extend into gear cavity  33  and does not contact teeth  79  of gear  7  which intermesh with teeth  80  of swing arm  9 ; rod cam  5  is oriented in cavity  31 , so that detent ball  18  is positioned against ramp  65  and held against ramp  65  by linear force exerted by biasing spring  19  against ball  18 ; and cam lever  53  of control rod  6  extends into cam lever slot  57 , wherein free side  62  of slot  57  contacts free side  53   a  of cam lever  53  with force sufficient to move control rod  6  in slots  43  and  44  to cause distal end  54  of pin  52  to compress biasing spring  56 . 
   In the opening position, rotation of cam  5  in cavity  31  is controlled, as hereafter explained by key  73 ; rotation of swing arm  9  in any direction is enabled because gear  7  can rotate in any direction. In this regard, swing arm  9  can rotate in any direction because rotation of gear  7  in any direction is not impeded by end  55  which does not contact teeth  79  of gear  7 . 
   As described above, the operating status of the handcuff of this invention as being in one of the closing, locked or opening positions is based on the position of detent ball  18  with respect to closing detent  59 , locking detent  58  or ramp  65 , respectively. Rotation of rod cam  5  moves detents  59  and  58  and ramp  65  with respect to detent ball  18 , which, of course, can only linearly slide within hole  38  in the space between cam space  31  and detent spring  19 . Accordingly, cam plate  15  is rotated by placing axial hole  78  of key  73  over either end of shaft  16  of rod cam  5  and then manually turning barrel  74  of key  73  with handle  75  to position one of detents  59  and  58  and ramp  65  with respect to detent ball  18 . 
   Manual turning force placed on handle  75  can be terminated when detent ball  18  is positioned in detent  58  or detent  59 . In those positions, rod cam  5  is stable and will not rotate in the absence of applied manual force. In contrast, rod cam  5  is not stable and will rotate if turning force is terminated when detent ball  18  is positioned on ramp  65 . In this regard, if manual turning force is terminated while ball  18  is on ramp  65 , then rod cam  5  will automatically rotate to position ball  18  in detent  59 . In short, the handcuff automatically reverts to closing position from opening position. The practical result is that manual force must be continually applied to rod cam  5  to maintain the handcuff in the opening position until no tooth of gear  7  is intermeshed with any tooth on swing arm  9 .

Summary:
An apparatus for controlling the rotation of a gear comprising rotating a cam which causes the linear movement of a rod to control the rotation of the gear, wherein the cam rotates within a confined space but not around a fixed axle. The apparatus is particularly useful for controlling the opening and closing movements of a handcuff whose operating elements are comprised of a swing arm and at least one gear having teeth which engage the teeth of the swing arm.