Abstract:
A set of handcuffs having an improved locking mechanism. The critical element of the locking mechanism is the utilization of a locking gear set that replaces the conventional pawl. The teeth in the locking arm are matched to the locking gear set and are always in constant and full contact with the locking gear set. This invention also uses a cam/cylinder locking device that controls the movement of the locking gear set. In the normal cam position the locking gear set will only turn in one direction, thus enabling the locking arm to close. In the second cam position the locking gear set will not turn in either direction. The cam can be rotated, through the use of a cylindrical key, in either directions. Rotation in one direction will select one of two locking positions. Rotation of the cylindrical key in the opposite direction will free locking gear set to rotate in the opposite direction thus disengaging the locking arm.

Description:
This is a continuation-in-part of U.S. 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 mechanism and to 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, usually made of metal, which, when employed, is ordinarily placed around the wrist or ankle of an individual. The apparatus, can be, and usually is, 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 and herein as “handcuffs” or as a “set of handcuffs.” 
     It is also known in the art to place handcuffs upon an individual to render such individual physically ineffective or powerless. Accordingly, handcuffs can be employed, for example, 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, then, 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, utterly defeats the purpose of the handcuffs. 
     As known in the art, a handcuff contains mechanisms which function to permit the apparatus to open and close and also function to prevent the apparatus from opening. The first function is referred to herein as the “operating mechanism.” The second function is referred to herein as the “locking mechanism.” 
     An example of a handcuff known in the art which includes an operating and a locking mechanism can be 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 herein 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 closed 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, for convenience, referred to herein as the “machinery space.” The machinery space can sometimes be further defined by cavities formed in a third plate positioned between the two exterior plates. The third plate thus separates the exterior plates and provides a cavity or cavities in which the operating and locking mechanisms are positioned. 
     Each exterior plate is ordinarily a unitary body comprised of a first section, referred to herein as a “cheek plate,” and a second section, referred to herein 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 stationary arm. The third plate, when employed, is positioned between the cheek plates and can be considered to be a part of the housing for mechanisms positioned in the machinery space. 
     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, which as stated, is 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 has been variously referred to as a curved locking arm or 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 and close the restraining space. In handcuffs known in the prior art the restraining space is opened by causing the respective teeth to disengage followed by rotating the swing arm out of the machinery space. 
     From the above description it is evident that a handcuff functionally comprises a restraining space and a machinery space. The prior art of particular interest herein is the specific operating and locking mechanisms employed in the machinery space. 
     The operating mechanism of a prior art handcuff is embodied in a substantially linear member enclosed in the machinery space which features a plurality of teeth mounted on one side thereof which are adapted to engage teeth on the swing arm. The prior art operating mechanism is hinged at one end and biased to urge the teeth on the member into engagement with the teeth on the swing arm. The mechanism can be thus characterized as a hinged pawl situated within the machinery space of the handcuff. The swing arm must enter the machinery space to 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 of the prior art thus employs a reciprocating action wherein the teeth on the pawl and the 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. 
     A prior art handcuff features a first operating position and a second operating position. The first operating position is referred to as the “ready-to-lock” position. In this position, the swing arm is permitted to swing inwardly into the machinery space of the handcuff to close and reduce the area of the restraining space, to thereby tighten the restraint around the wrist or ankle of an individual, but the handcuff is not permitted to be loosened or opened because the teeth of the pawl are designed to permit inward, but not outward, movement of the teeth on the swing arm. It is believed that the shape of the teeth of the pawl and the teeth of the swing arm combine to prevent the swing arm from rotating out of the machinery space of the handcuff. 
     The second operating position, referred to as the “double locked” or secondary locking position, employs, as the locking mechanism, a movable physical barrier, such as a rod or a bar, positioned within the machinery space of the handcuff to prevent the pawl from performing the mentioned reciprocating action and, therefor, prevents the swing arm from rotating around the hinge end of the stationary arm. In the second operating position, the swing arm cannot be moved in either direction (i.e., inwardly into or outwardly out of the machinery space of the handcuff), because the pawl teeth are caused to remain in continuous contact with the teeth of the swing arm by the locking mechanism to prevent any movement of the swing arm. In this regard, the reciprocating movement of the pawl to disengage the pawl teeth is prevented by the mentioned rod or bar positioned between the reciprocating, i.e., free, end of the pawl and the inner surfaces of the cheek plates of the handcuff. 
     As mentioned, prior art handcuffs, and similar such restraints, employ a combination locking and operating mechanism featuring a swing arm having ratchet teeth in operable combination with the teeth of a pawl. These mechanisms are not secure because they can be opened by force, for example by jimmying and jarring. There is, thus, a need for a locking and an operating mechanism which resists being unlocked by leverage, impact and rotational forces which employ tools, such as lock picks and shims. 
     It is well known that handcuffs and restraints employing the prior art ratchet and pawl mechanism can be forcibly opened by use of a thin flat item, such as a small metal ruler or by a plastic credit card. In this regard, and as previously mentioned, the prior art ratchet and pawl operating and locking mechanism, in the very act of contacting and intermeshing the teeth of the pawl with the teeth of the swing arm, inherently involves the teeth on the pawl and the teeth on the swing arm continually alternating between an engaged and a disengaged condition. This inherent action can be exploited in a technique called “jimmying,” wherein a shim, such as a thin flat item, is forced between the teeth of the swing arm and the teeth of the pawl to overcome the biasing source and raise the pawl by an amount sufficient to interrupt contact between the teeth of the pawl and the ratchet teeth to enable the outward movement of the swing arm to thereby open the restraining space. 
     It is further known that the above described prior art ratchet and pawl handcuffs and restraining devices employ a simple rod or bar, which, when properly positioned, prevents the pawl from being raised by a shim. Positioning the rod or bar can be accomplished by inserting the pin end of the handcuff key into a small hole in the side of the handcuff to move the bar. The locking mechanism can be defeated by striking the handcuff on a solid object, such as a rock or pavement, to jar the bar out of position. Once the secondary locking mechanism has been jarred out of position, the handcuffs or restraints can then be jimmied as described above. 
     A prior art handcuff key is little more than a piece of metal which, upon rotation within the key way, positions a cam to cause or prevent vertical movement of the pawl. The rotation of the key about its longitudinal axis requires so little torque to move the cam that an operable key can be formed from a paper clip. 
     Furthermore, in a technique called “picking,” a paper clip, or other bendable yet sturdy element, can be modified and used along with other small pieces of wire to perform the same function as the key. 
     In view of the problems involving the operating and locking mechanisms of handcuffs of the prior art, it is an object of this invention to provide 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. Another object of this invention is to provide a handcuff having a locking mechanism which can permit or prevent movement of the operating mechanism. These and other objects, advantages and features provided by this invention will become apparent to those persons skilled in the art from a consideration of the following description and drawings which describe the apparatus of this invention and the manner and process of making and using the same. 
     THE INVENTION 
     Summary of the Invention. 
     This invention provides an apparatus useful as a handcuff. The apparatus is comprised of a housing having an operating and a locking mechanism enclosed therein, wherein 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 divided into a first section called a “cheek plate,” and a second section called a “plate arm.” The plates are spaced apart to provide a machinery space between the cheek plates and a curvilinear stationary arm defined by the 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 is an elongated curvilinear body having a pivot end and a free end. The pivot end of the swing arm is rotatably connected to the hinge end of the stationary arm. The swing arm extends in an arc toward the machinery space from 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. 
     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 this invention is housed in the machinery space. In one embodiment, the operating mechanism of this invention can be a toothed wheel, that is, a gear, whose teeth engage the teeth mounted on the swing arm. In another embodiment, the operating mechanism of this invention can be comprised of two gears, each of whose teeth can simultaneously engage the teeth mounted on the swing arm. In still another embodiment, the operating mechanism of this invention can be comprised of an array of three intermeshing gears having two gears, referred to herein as “working gears,” whose teeth can simultaneously engage the teeth mounted on the swing arm, and a third gear, referred to herein as an “idler gear,” whose teeth are continually and simultaneously engaged with the teeth on the two working gears. In still another embodiment, the operating mechanism can be comprised of a single working gear and an idler gear. 
     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 into machinery space to place the handcuff into the closed position; and when the swing arm is being rotated out of the machinery space to place the handcuff in an open position. 
     Any working gear of the operating mechanism having teeth engaged, that is, in contact and intermeshed, with teeth on the swing arm must rotate to enable any rotational movement of the swing arm. This invention, accordingly, further provides a multi-function locking mechanism which controls the rotation of the gears. The locking mechanism of this invention is housed in the machinery space in a location separate from the operating mechanism. 
     In a first locking position, referred to herein as the “closing position,” the locking mechanism is adjusted 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 herein as the “locked position,” the locking mechanism is adjusted 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 herein as the “free position,” the locking mechanism is adjusted to permit rotation of the gears in any direction to permit rotation of the swing arm in any direction. 
     One specific embodiment of this invention comprises an array of three intermeshing gears in the operating mechanism consisting of two working gears and one idler gear wherein a control pin directly contacts a working gear. Another specific embodiment of this invention also comprises an array of three intermeshing gears in the operating mechanism consisting of two working gears and one idler gear wherein a control pin directly contacts the idler gear. In terms of operation, the two embodiments operate in the same way, that is, rotation of the gears is controlled by a pin in direct contact with a gear. 
     In view of the above, it will be appreciated that the operating mechanism of this invention is broadly comprised of a working gear and a swing arm. In this regard, the working gear is rotatably mounted on a gear axle which is perpendicularly attached to a planar base, and the swing arm is rotatably mounted on a swing arm axle which is also perpendicularly attached to the planar base a fixed distance from the gear axle. 
     The working gear is a wheel having a first radius with teeth mounted on the outer edge of the wheel which rotates around the gear axle in a plane parallel to the plane of the planar base. 
     The swing arm is a curvilinear member having a first end and a second end with teeth mounted on the outer edge of the first end. The distance from the outer edge of the first end of the swing arm to the swing arm axle is the second radius. The swing arm rotates around the swing arm axle in a plane parallel to the planar base. 
     The mentioned fixed distance is substantially equal to the sum of the lengths of the first radius and the second radius. Accordingly, the teeth on the working gear and the teeth on the swing arm contact and intermesh each with the other upon rotation of the working gear around the gear axle and rotation of the swing arm around the swing arm axle. The teeth on the working gear and the teeth on the swing arm are thus adapted to intermesh upon contact., 
     The operating mechanism of this invention can further include, in one embodiment, a linear rod slidably mounted on, and parallel to, the planar base in a position opposed to the working gear, and preferably perpendicular to the gear axle; or, in another embodiment, a linear rod slidably mounted on, and parallel to, the planar base in a position opposed to the idler gear and preferably perpendicular to the idler gear axle. The linear rod has a proximal end, a distal end and a biasing means to urge the proximal end of the rod into contact with the teeth on the working gear or the idler gear as the case may be. The proximal end of the rod is adapted to contact the teeth on the designated gear to permit rotation of the gear around its axle in one rotational direction while preventing rotation of the gear around its axle in the opposite rotational direction. 
     The operating mechanism of this invention can be further controlled by a locking mechanism comprised of a cam in operable combination with a cam lever, which is rigidly attached to the linear rod at a point intermediate the proximal end and the distal end of the linear rod. 
     The cam, referred to herein as a yoke, is a plate having an axle end and a forked end linearly spaced apart from the axle end. 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 wherein the second leg is spaced apart from and, preferably, parallel to 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 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 causes contact between the cam lever and one of the first leg and second leg which, in consequence, controls rotation of the working gear and swing arm. 
     The preceding description has been generally limited to a handcuff comprised of an operating mechanism consisting of one working gear, a swing arm and a linear rod. The operating mechanism can be further comprised of an idler gear and a second working gear. In this regard the operating mechanism can include a combination of two working gears, a combination of one working gear and the idler gear, or a combination of two working gears and an idler gear. The linear rod can be positioned to contact any of the gears. 
     The locking mechanism 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. 
     It is believed that the specific locations of the operating and locking mechanisms of this invention within separate machinery spaces as well as structural features of the swing arm and the machinery spaces, serve to prevent the insertion of any object, such as a shim, between the swing arm teeth and the gear teeth and/or between the locking mechanism and the gear teeth. Even if any object is inserted between any of the various teeth and mechanisms, then, It is further believed, that the shim will become wedged in the teeth and or gears which will operate to prevent any rotation of the gears and thus prevent any rotation of the swing arm. 
     It is clear that the operating mechanism of the present invention replaces the pawl of the prior art with a gear or gears, which are constantly, and fully engaged with the teeth of the swing arm. The operating gears cannot be jimmied open by the insertion of a metal or plastic shim. Additionally, the locking mechanism utilizes a yoke that is positioned and formed to make it difficult to pick by anyone. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a three dimensional representation of a set of handcuffs of the present invention. 
     FIG. 1 a  is a three dimensional representation of a key employed to manipulate the locking mechanism of the present invention. 
     FIG. 2 is a plan view of a handcuff of the present invention having an exterior plate removed to reveal the swing arm, the interior plate, the machinery spaces, the operating mechanism and the locking mechanism configured in the free position. 
     FIG. 3 is a modified view of FIG. 2 showing the locking mechanism configured in the closing position. 
     FIG. 4 is a modified view of FIG. 2 showing the locking mechanism configured in the locked position. 
     FIG. 5 is a partial sectional view taken in the direction of cut line  5 — 5  of FIG. 3 showing the yoke, yoke axle and detent assembly of the locking mechanism and the control pin of the operating mechanism. 
     FIG. 6 is a sectional view taken in the direction of cut line  6 — 6  of FIG. 4 showing the control pin and the operating relationship of the control pin and the gears of this invention. 
     FIG. 7 is a sectional view taken in the direction of cut line  7 — 7  of FIG. 1 showing the connection between the pivot end of the swing arm and the hinge end of the stationary arm. 
     FIG. 8 is a partial sectional view taken in the direction of cut line  8 — 8  of FIG. 1 showing a connection between each handcuff in a set of handcuffs. 
     FIG. 9 is a partial sectional view taken in the direction of cut line  9 — 9  of FIG. 2 showing the operating relationship between the swing arm and the cheek plates. 
     FIG. 10 is an end view of the key of FIG. 1 a.    
     FIG. 11 is a side view the of key of Figure 1 a.    
     FIG. 12 a partial sectional view taken in the direction of cut line  12 — 12  of FIG. 1 showing the relationship between the key guide for the key shown in FIG. 1 a  and the locking mechanism shown in FIG.  5 . 
     FIG. 13 is a plan view of a handcuff of the present invention having an exterior plate removed to reveal the swing arm, the interior plate, the machinery spaces, the operating mechanism and the locking mechanism configured in the closing position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     This invention provides an apparatus useful as a handcuff. The apparatus is comprised of a housing having an operating and a locking mechanism enclosed therein, wherein the housing, as shown in FIG. 1, is comprised of at least two, substantially identically shaped, opposed, substantially parallel, plates,  6  and  7 , and a swing arm,  22 . Each plate is a unitary body having an inside surface, an outside surface, an arm side, A, and an open side, B. Each plate, such as plate  6 , for convenience of reference herein, is divided into a first section,  6   a , referred to as a “cheek plate,” and a second section,  6   b , 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 this invention is housed in the machinery space between the opposed cheek plates. In one embodiment, the operating mechanism of this invention can be a toothed wheel, that is, a gear, whose teeth engage the teeth mounted on the swing arm. In another embodiment, the operating mechanism of this invention can be comprised of two gears, each of whose teeth can simultaneously engage the teeth mounted on the swing arm. In still another embodiment, the operating mechanism of this invention, as shown in FIGS. 2-4, can be comprised of an array of three intermeshing gears having two gears, referred to herein as “working gears,” whose teeth can simultaneously engage the teeth mounted on the swing arm, and a third gear, referred to herein as an “idler gear,” whose teeth are continually and simultaneously engaged with the teeth on the two working gears. In still another embodiment, the operating mechanism can be comprised of a single working gear and an idler gear. 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, as shown in FIG. 4, when the swing arm is being rotated toward the open side of the plates to place the handcuff into the closed position, as shown in FIG. 3, and when the swing arm is being rotated away from the open side of the plates to place the handcuff in an open position, as shown in FIG.  2 . 
     Any working gear of the operating mechanism having teeth engaged, that is, in contact and intermeshed, with teeth on the swing arm must rotate to enable any rotational movement of the swing arm. This invention, accordingly, further provides a multi-function locking mechanism which controls the rotation of the gears. The locking mechanism of this invention is housed in the machinery space between the opposed cheek plates in a location separate from the operating mechanism. 
     In a first locking position, shown in FIG. 3, referred to herein as the “closing position,” the locking mechanism is positioned to permit rotation of the gears in one direction to thereby permit closing rotation of the swing arm, and to prevent rotation of the gears in the opposite direction to thereby prevent opening rotation of the swing arm. In a second locking position, shown in FIG. 4, referred to herein as the “locked position,” the locking mechanism is positioned to prevent any rotation of the gears in any direction to thereby prevent any rotation of the swing arm in any direction. In a third locking position, shown in FIG. 2, referred to herein as the “free position,” the locking mechanism is positioned to permit rotation of the gears in any direction to thereby permit rotation of the swing arm in any direction. 
     FIGS. 2-4 illustrate one specific embodiment of this invention featuring an array of three intermeshing gears in the operating mechanism consisting of two working gears and one idler gear wherein a control pin directly contacts a working gear. In another embodiment of this invention, FIG. 13 illustrates another specific embodiment of this invention also featuring an array of three intermeshing gears in the operating mechanism consisting of two working gears and one idler gear, but wherein the control pin directly contacts the idler gear. In terms of operation, FIG. 13 is comparable to FIG.  3 . Thus, in a first locking position, shown in FIG. 13, referred to herein as the “closing position,” the locking mechanism is positioned to permit rotation of the gears in one direction to thereby permit closing rotation of the swing arm, and to prevent rotation of the gears in the opposite direction to thereby prevent opening rotation of the swing arm. 
     Having, thus, generally alluded to the apparatus as a whole, it will be appreciated that the operating mechanism of this invention is broadly comprised of a first working gear and a swing arm. In this regard, the first working gear is rotatably mounted on a first gear axle which is perpendicularly attached to a planar base, and the swing arm is rotatably mounted on a swing arm axle which is also perpendicularly attached to the planar base a first fixed distance from the first gear axle. 
     The first working gear is a wheel having a first radius. Teeth are mounted on the outer edge of the wheel which rotates around the first gear axle in a plane parallel to the plane of the planar base. 
     The swing arm is a curvilinear member having a first end and a second end. Teeth are mounted on the outer edge of the first end. The distance from the outer edge of the first end of the swing arm to the swing arm axle is referred to as the second radius. The swing arm rotates around the swing arm axle in a plane parallel to the planar base. 
     The mentioned first fixed distance is substantially equal to the sum of the lengths of the first radius and the second radius. Accordingly, the teeth on the first working gear and the teeth on the swing arm contact and intermesh each with the other upon rotation of the first working gear around the first gear axle and rotation of the swing arm around the swing arm axle. The teeth on the first working gear and the teeth on the swing arm are thus adapted to intermesh upon contact. 
     The operating mechanism of this invention, as mentioned above, can further include, in one embodiment, 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 axle; or, in another embodiment, a control pin comprising a linear rod slidably mounted on, and parallel to, the fixed planar base in a position opposed to the idler gear and preferably perpendicular to the idler gear axle. The linear 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 or the idler gear as the case may be. The proximal end of the rod is adapted to contact the teeth on the designated gear to permit rotation of the gear around its axle in one rotational direction while preventing rotation of the gear around its axle in the opposite rotational direction. 
     The operating mechanism of this invention can be further controlled by a locking mechanism which converts rotational motion to linear motion. The locking mechanism is thus comprised of a cam in operable combination with a cam follower, referred to herein 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 is a plate in the shape of a yoke 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, accordingly, referred to herein 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 wherein the second leg is spaced apart from and, preferably, parallel to 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. 
     As seen in FIG. 2, 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 and permit rotation of the gears in any rotational direction. As seen in FIG. 4, 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 and prevent rotation of the gears in any rotational direction. As seen in FIGS. 3 and 13, configuring the yoke in a neutral position permits contact between the cam lever and the inside surface of the first leg, but does not urge the rod against the biasing means at the distal end of the rod, thus permitting closing rotation of the swing arm, but preventing opening rotation of the swing arm. 
     The operating mechanism of this invention can be further comprised of an idler gear, a wheel having a third radius and teeth mounted on the outer edge the wheel, wherein the teeth on the idler gear and the teeth on the first working gear are in contact each with the other. The teeth on the idler gear and the teeth on the first working gear are adapted to intermesh upon contact. 
     The idler gear is rotatably mounted on the idler gear axle which is perpendicularly attached to, and positioned on, the planar base a second fixed distance from the first gear axle, and a third fixed distance from the swing arm axle. The idler gear rotates around the idler gear axle in a plane parallel to the plane of the planar base. 
     The operating mechanism of this invention can be further comprised of a second gear axle and a second working gear wherein the second gear axle is perpendicularly attached to and positioned on the planar base a fourth fixed distance from the first gear axle, a fifth fixed distance from the swing arm axle and a sixth fixed distance from the idler gear axle. The second working gear is rotatably mounted on the second gear axle to enable the second working gear to rotate around the second gear axle in a plane parallel to the plane of the base. The second working gear is a wheel having a fourth radius and teeth mounted on the outer edge thereof. 
     The fifth fixed distance is substantially equal to the sum of the lengths of the second radius and the fourth radius whereby the teeth on the second working gear and the teeth on the swing arm are in contact and intermesh each with the other upon rotation of the second working gear around the second gear axle and rotation of the swing arm around the swing arm axle. The teeth on the second working gear and the teeth on the swing arm are thus adapted to intermesh upon contact. In a preferred embodiment, the radius of the second working gear, that is, the fourth radius, is equal to the radius of the first working gear, that is, the first radius, and the fifth fixed distance is equal to the first fixed distance. 
     It is preferred that the teeth on the idler gear and the teeth on the second working gear also contact each other. Accordingly, the teeth on the idler gear and the teeth on the second working gear are adapted to intermesh upon contact and the fourth radius is equal to the third radius. It is also preferred that the third radius is equal to the first radius. 
     The locking mechanism of this invention can be, and is preferably, 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 previously mentioned closing position or the previously mentioned locked position. 
     Refer now to the Figures, and particularly to FIGS. 1-4 and  13 . Every detail of FIG. 13 is not described, but notice that the reference numerals employed in FIG. 13 are 400 numbers greater than the numerals shown in FIGS. 1-12. Thus, for example, reference numeral  10  in FIG. 3 corresponds to reference numeral  410  in FIG.  13 . Reference is made to a numeral in FIG. 13 only if clarification is believed to be served by such reference. 
     Thus, there is shown a set of handcuffs  1  broadly comprised of first handcuff  2  and second handcuff  4  positioned end-to-end and flexibly connected together. In this regard, proximal end  3  of handcuff  2  is spaced apart from and flexibly connected to proximal end  3   a  of handcuff  4  by coupling links  25 ,  26  and  27 . Handcuff  2  and handcuff  4  can be identical in construction and operation and are shown as such in FIG. 1, accordingly, the following description of handcuff  2  is fully applicable to handcuff  4 . Therefor, only handcuff  2  is described in detail. Reference is made to handcuff  4 , or any of its elements, only if clarification is believed to be served by such reference. 
     Handcuff  2  is an apparatus comprised of the combination of planar top plate  6 , which is aligned with and parallel to, planar bottom plate and  7 , housing block  20 , containing the operating and locking mechanisms of this invention, and curvilinear swing arm  22 . Plates  6  and  7  function as a base for support of housing block  20  and swing arm  22 . Plates  6  and  7  are identical in shape, are opposed, are in alignment and are spaced apart by, and rigidly attached to, housing block  20  by a plurality of rivets  11 . Each of plates  6  and  7  includes top cheek plate  6   a , bottom cheek plate  7   a , top plate arm  6   b  and bottom plate arm  7   b . Plate arms  6   b  and  7   b  combine to form stationary arm  8  which broadly operates with swing arm  22  to form closed ring  9  having an open center. More specifically, stationary arm  8  and swing arm  22  each have opposed concave sides which, together with the concave interior edges of cheek plates  6   a  and  7   a  cooperate to form closed ring  9  which is adapted to be fitted around an oval or circular object, such as the wrist or ankle of an individual. The open center of closed ring  9  is the restraining space of handcuff  2 . 
     Housing block  20  is positioned in proximal end  3  of handcuff  2  between cheek plates  6   a  and  7   a . Pivot pin  14  is positioned in distal end  5  of handcuff  2  between terminal ends  13   a  and  13   b  of plate arms  6   b  and  7   b . Plate arms  6   b  and  7   b  combine to form stationary arm  8  which serves in a transition capacity between, and rigidly connects, proximal end  3  to distal end  5 . Pin end  12  of swing arm  22  is rotatably attached to pivot pin  14 . 
     Proximal end  3  of handcuff  2  is a closed body formed by the combination of cheek plates  6   a  and  7   a  and housing block  20 . Housing block  20  contains cavities  107 ,  109 ,  111 ,  101 ,  103  and  105  which enclose the locking mechanism and the operating mechanism of this invention. The operating and locking mechanisms are described below. It is to be understood that FIGS. 2-6 and  9  deliberately do not show plate  6  of handcuff  2  to enable the convenient description and visualization of the contents of housing block  20 . Also, since handcuff  2  and handcuff  4  are identical, the reference numerals employed in this description apply with equal facility to each of plates  6  and  7  unless a difference in reference numeral identification for otherwise comparable parts is believed to be desirable. 
     Swing arm  22  and stationary arm  8  are joined in distal end  5  of handcuff  2 . As is more clearly shown in FIG. 2, stationary arm  8 , comprised of the combination of plate arms  6   b  and  7   b , is in the shape of the letter “C” wherein each of plate arms  6   b  and  7   b  is a curvilinear structure extending from the arm sides “A” of cheek plates  6   a  and  7   a  in proximal end  3  to terminal ends  13   a  and  13   b  in distal end  5 . It is to be understood that terminal ends  13   a  and  13   b  combine to form the hinge end of stationary arm  8 . As illustrated in FIG. 7, terminal end  13   b  of plate arm  7   b  and terminal end  13   a  of plate arm  6   b  are each equipped with a hole. The holes are in alignment. 
     Swing arm  22  is a single curvilinear member comprised of free end  10  and pin end  12 . Pin end  12  is equipped with a hole. Pin end  12  of swing arm  22  is adapted for insertion between the hinge end of stationary arm  8 . Pivot pin  14  press fits into the holes in terminal ends  13   a  and  13   b  of plate arms  6   b  and  7   b  so that it will not move. However, as seen in FIG. 7, the hole in pin end  12  of swing arm  22  is slightly larger in diameter than the diameter of pin  14  so that swing arm  22  can freely rotate about pin  14 . The holes in terminal ends  13   a  and  13   b  and the hole in pin end  12  are positioned in alignment to form a continuous hole into which pivot pin  14  is inserted to thereby rotatably connect swing arm  22  to plate arms  6   b  and  7   b.    
     Swing arm  22 , stationary arm  8  and cheek plates  6   a  and  7   a  combine to form the restraining space in closed ring  9 . Accordingly, as shown in FIG. 1, swing arm  22  rotates around pivot pin  14  and inwardly into proximal end  3  to form the restraining space with stationary arm  8 . 
     As seen in FIG. 2, the distance from outer edge  18  to inner edge  17  of pin end  12  is substantially constant. However, the distance from outer edge  16  to inner edge  19  of free end  10  is not constant. In this regard, the distance from outer edge  16  to inner edge  19  of free end  10  diminishes from a maximum value at point  21  of outer edge  16  to a minimum value at point  23  of outer edge  16 . The difference in the width of free end  10  from point  21  to point  23 , as just mentioned, is caused by the fact that the radial distance from the center of pin  14  to outer edge  16  between points  21  and  23  is constant. The reason for this constant radial distance shall become more clear herein below. Outer edge  16  is equipped with a multiplicity of gear teeth  16   a  between points  21  and  23 . 
     Edge  29  of cheek plate  6   a  and edge  31  of cheek plate  7   a  each extend beyond housing block  20  adjacent closed ring  9  by an amount sufficient to at least be in alignment with inner edge  19  of free end  10  of swing arm  22 . As seen in FIGS. 1,  2  and  9 , edges  29  and  31  and side  20   a  of housing block  20  adjacent to closed ring  9  form slot  20   b  into which free end  10  is rotated. Slot  20   b  covers and protects gear teeth  16   a  when handcuff  2  is in the closed position to thereby form closed ring  9 . 
     Referring now to FIG. 9, free end  10  of swing arm  22  is shown to have curvilinear groove  24  cut in one surface of free end  10  adjacent to outer edge  16 . Curvilinear groove  28  is cut in the reverse surface of free end  10  and is in alignment with groove  24 . Each of grooves  24  and  28  are concentric to the curve of outer edge  16  of free end  10 . The nominal radii of each of grooves  24  and  28  are equal to each other but are less than the radial distance from pin  14  to edge  16 . It is understood that the radii of the curvilinear grooves  24  and  28  are measured from the center of pivot pin  14 . 
     The inner surfaces of cheek plates  6   a  and  7   a  adjacent to closed ring  9  each have a raised continuous ridge or boss formed thereon. Note boss  29  on cheek plate  7   a . The boss on cheek plate  6   a  is not shown. Each boss is curvilinear in shape and is adapted to be slidably inserted into grooves  28  and  24 , respectively. Each boss continuously extends at least from the linear outer edge of cavity  103  on side  50  of block  20  to the linear outer edge of cavity  101  on side  52  of housing block  20 . 
     The bosses on plates  6   a  and  7   a  cooperate with grooves  24  and  28  to guide free end  10  of swing arm  22  into and out of slot  20   b  and to stabilize free end  10  in slot  20   b  so that the teeth  16   a  on free end  10  and the teeth of gears  102  and  104 , described below, remain in contact and intermeshed. 
     The combination of the described grooves and bosses, in view of the extension of the bosses beyond the limits of the indicated cavities in housing block  20  which contain the operating mechanism of this invention, act to block the insertion of any wedge or lever device into the cavities by way of slot  20   b.    
     Referring to FIG. 8, the connection of handcuff  2  and handcuff  4  is illustrated by reference to coupling link  26  having hole  36  drilled through one end thereof and another hole  36   a , not shown, drilled through the other end thereof. The hole in each end of coupling link  26  is aligned with a hole, not shown, drilled in housing block  20  parallel to side  54 . The hole in block  20  extends, for example, from open side “B” of cheek plate  6   a  toward arm side “A” of cheek plate  6   a . The width of each coupling link, such as link  26  as shown in FIGS. 2-4, is adapted to be slidably positioned in aligned slots, such as slot  26   a , cut in plates  6   a ,  7   a  and block  20 . Hole  36   a  is placed in alignment with the hole in block  20 . Pin  38  is positioned in the holes drilled in the coupling links and housing block to thereby form a hinged connection between handcuff  2  and handcuff  4 . Pin  38  is fixed in block  20 , but the holes in the coupling links are adapted to permit the links to rotate around pin  38 . The thickness of link  26  is equal to or less than the combined thicknesses of cheek plates  6   a  and  7   a  and block  20  and the distance between holes  36  and  36   a  are selected so that the set of handcuffs can fold to a substantially flat unit. It is believed that the combination of links  25 ,  26  and  27  cooperate to permit the handcuffs to hinge around an axis lying between handcuffs  2  and  4 , but prevent any other movement of one handcuff relative to the other. Accordingly, one handcuff cannot be manipulated to act as a lever to break the hinge end of the other. 
     Particular attention is now invited to FIGS. 2-4. Observe that housing block  20  is a solid material having cavities formed therein, wherein the outer boundaries of block  20  include swing arm side  50 , stationary arm side  52 , coupling link side  54  and gear side  20   a . Swing arm side  50  is substantially perpendicular to coupling link side  54 . Gear side  20 a is curvilinear in shape, wherein the curve of side  20   a  from point  2   1   a  to point  23   a  is concentric to the curve of free end  10  of swing arm  22 . In this regard, the curve of side  20   a  is generated by a radius, extending from the center of pin  14 , which is greater than the radius which extends from pin  14  to generate the curve of free end  10  from point  21  to point  23 . Side  20   a  is, thus, adapted to permit the slidable insertion and removal of free end  10  into and out of slot  20   b  of handcuff  2 . It is clear that side  20 a intersects side  50  at point  21   a  at an acute angle. 
     Stationary arm side  52  of block  20  is a compound curve substantially in the shape of the letter “S.” In this regard, side  52  curves inwardly to join coupling link side  54  in a substantially perpendicular manner, but curves outwardly to conform with the curved shape of plate arm  7   b . Side  20   a  intersects side  52  at point  23   a  to form an acute angle. 
     The operating mechanism of this invention is located in housing block  20 . The operating mechanism is broadly comprised of an array of gears  102 , 104  and  106 , control pin  108 , and control pin spring  118 . 
     Gears  102  and  104 , specifically referred to herein as working gears, and idler gear  106 , are positioned in cavities  101 ,  103  and  105 , respectively. Control pin  108  is principally positioned in cavity  111  and control pin spring  118  is positioned in cavity  109 . The locking mechanism of this invention is positioned in cavity  107 . Cavity  101  joins cavity  105  to enable gear  102  to contact gear  106 . Cavity  105  joins cavity  103  to enable gear  106  to contact gear  104 . In the case of FIGS. 2-4, cavity  111  joins cavity  101  to enable the proximal end of pin  108  to contact gear  102 . (In the case of FIG. 13, cavity  511  joins cavity  505  to enable the proximal end of pin  508  to contact gear  506 .) Cavity  111  joins cavity  109 . The distal end of pin  108  is placed in cavity  109  to enable the distal end of pin  108  to contact spring  118 . Cavity  111  joins cavity  107  to enable contact between control pin  108  and the locking mechanism of this invention. Cavities  101  and  103  join slot  20   b  to enable gears  102  and  104  to contact teeth  16   a  of free end  10  of swing arm  22 . 
     The diameters of working gears  102  and  104  and the diameter of idler gear  106  are, preferably, identical wherein the number of teeth on each such gear is equal to the number of teeth on each of the other gears. 
     Idler gear  106  rotates in cavity  105  around gear axle  30  which is perpendicularly and transversely fixed in aligned holes  30 a and  30   b  drilled into cheek plates  6   a  and  7   a , respectively. Axle  30  is press fit into holes  30   a  and  30   b  so that axle  30  will not move. Idler gear  106 , however, is sized to rotate around axle  30 . The positioning of axle  30  enables idler gear  106  to rotate in a plane parallel to the planes of cheek plates  6   a  and  7   a . Working gear  102  and working gear  104  rotate in cavities  101  and  103  around axles  32  and  34 , respectively. Like axle  30 , axles  32  and  34  are perpendicularly and transversely fixed in aligned holes  32   a  and  32   b  and  34   a  and  34   b  drilled in cheek plates  6   a  and  7   a . Axles  32  and  34  are press fit into holes  32   a  and  32   b  and  34   a  and  34   b , respectively, so that the axles will not move in the holes. Working gears  102  and  104 , however, are sized to rotate around axles  32  and  34 . The positioning of axles  32  and  34  enables working gears  102  and  104  to rotate in a plane parallel to the planes of cheek plates  6   a  and  7   a . It is preferred that gears  102 ,  104  and  106  all rotate in the same plane. 
     Each of gears  102 ,  104  and  106  are wheels equipped with teeth mounted on the outer edges thereof. Each gear has the same number of teeth which are sized to contact and intermesh without restriction upon rotation of the gears around the mentioned axles. Furthermore, the teeth of gears  102  and  104  and teeth  16   a  of swing arm  22  are sized to contact and intermesh without restriction whenever swing arm  22  moves inwardly into or outwardly from slot  20   b  of handcuff  2 . 
     Axles  30 ,  32  and  34  are placed in cavities  105 ,  101  and  103 , respectively, in positions designed to enable the teeth of idler gear  106  to simultaneously contact and intermesh with the teeth of working gears  102  and  104  and to enable the teeth of working gears  102  and  104  to also simultaneously contact and intermesh with teeth  16   a  of swing arm  22 . 
     Observe FIGS. 2-4 and notice, to enable the contact and intermeshing of the teeth of gears  102 ,  104  and  106  and the teeth  16   a  on swing arm  22 , that the diameters of cavities  101 ,  103  and  105  are greater than the diameters of gears  102 ,  104  and  106 ; that cavity  101  intersects cavity  105  and side  20   a ; and that cavity  103  also intersects cavity  105  and side  20   a . Notice further that the outer sides of cavities  101  and  103  are not curvilinear. 
     The teeth of gears  102  and  104  penetrate slot  20   b  as the gears rotate in their respective cavities so that at least one tooth of at least one gear is always in contact with at least one tooth of the swing arm whenever the swing arm is either entering or exiting slot  20   b  of handcuff  2 . Accordingly, the operation of this invention requires that the operating mechanism be comprised of at least one gear and that at least one tooth of that at least one gear contact and intermesh with at least one tooth  16   a  of swing arm  22 . It is preferred that at least one tooth of working gear  102  contact and intermesh with at least one tooth of idler gear  106  and at least one tooth  16   a  of swing arm  22 . It is further preferred that at least one tooth of working gear  104  also contact and intermesh with at least one tooth of idler gear  106  and at least one tooth  16   a  of swing arm  22 . To obtain at least four points of simultaneous contact as shown in FIGS. 2-4 and  13  it is important that the array of gears be positioned as shown and disclosed to provide such contact. 
     The operating mechanism of this invention, in addition to being comprised of at least one gear having teeth in operable combination with the teeth of swing arm  22 , also comprises a gear rotation control assembly comprised of control pin  108  and control spring  118 . 
     Control pin  108  operates in combination with the teeth of at least one gear to control the rotation of the said at least one gear and, therefor, of the array of gears as shown in FIGS. 2-4. Referring to FIGS. 3,  4 ,  5 ,  6  and  12 , control pin  108  comprises a linear rod slidably maintained in two rectangular slots defined by cheek plates  6   a  and  7   a  and cavities  109  and  111  in housing block  20 . The rod is supported by, and parallel to, cheek plates  6   a  and  7   a . The linear rod is positioned to oppose working gear  102  to enable the proximal end  108   a  of the rod to contact the teeth of gear  102 . (In the case of FIG. 13, the linear-rod is positioned to oppose idler gear  506  to enable the proximal end  508   a  of the rod to contact the teeth of gear  506 .) The linear rod is preferably perpendicular to gear axle  32 . (In the case of FIG. 13, the linear rod is preferably perpendicular to gear axle  430 .) 
     The combination of cheek plates  6   a  and  7   a  and cavity  111  and the combination of cheek plates  6   a  and  7   a  and cavity  109  define two separate rectangular cross sections. Accordingly, the linear rod of control pin  108  also has two rectangular cross sections. It is believed that the rectangular cross sections of the rod, confined as it is within the defined rectangular cross sections, stabilizes the rod and prevents it from rotating about its linear axis. The reason for the anti rotation feature of the linear rod will become apparent below. Other structures for preventing rotation of the rod in cavity  111  are within the skill of the art. 
     The rod consists of shaft  108   b  which separates proximal end  108   a  and distal end  108   c . Proximal end  108   a  of the linear rod of control pin  108 , by operation of the invention, as shown in FIG. 4, can be caused to move into cavity  101  and maintain contact with the teeth of working gear  102  and, as shown in FIG. 2, can be caused to remain in cavity  111  to prevent contact with the teeth of working gear  102 . (In the case of FIG. 13, proximal end  508   a  of the linear rod of control pin  508  can be caused to move into cavity  505 .) As seen in FIG. 3, the cross section of the tip of proximal end  108   a  is in the shape of a wedge having a slanted side and a flat side, wherein the slanted side of the wedge, as shown, faces in the direction of the teeth of swing arm  22  and the flat side of the wedge, as shown, faces in the direction of coupling links  25 ,  26  and  27 . It is further seen in FIG. 3, that the angle of the wedge is adapted to enable the wedge to fit in the valley or space between immediately adjacent teeth in gear  102 . (In the case of FIG. 13, the slanted side of the of the wedge faces away from the teeth of the swing arm.) It is apparent that the slanted side of the wedge faces the teeth of the designated gear as the gear rotates in the closing direction. 
     Distal end  108   c  of the linear rod of control pin  108  is adapted to linearly abut spring  118 . Spring  118 , acting on distal end  108   c , functions to urge the rod, and ultimately proximal end  108   a , into contact with the teeth of gear  102  (gear  506  in FIG.  13 ). As shown in FIG. 3, control spring  118  and distal end  108   c  are positioned in cavity  109 . The width of cavity  109  is greater than the width of cavity  111 . A shoulder is, thus, produced in housing  20  at the intersection of cavity  109  and  111 . The width of distal end  108   c  is greater than width of the slot which slidably supports shaft  108   b . Accordingly, the linear movement of control pin  108  toward gear  102  is controlled by the shoulder at the intersection of cavities  109  and  111  which acts against distal end  108   c  to limit the movement of control pin  108 . 
     In the closing position, as shown in FIG. 3, contact between distal end  108   c  and the mentioned shoulder between cavities  109  and  111  and the movement of proximal end  108   a  toward gear  102  (gear  506  in FIG. 13) is prevented by the contact between lever  110  and leg  212 . In the locked position, as shown in FIG. 4, contact between lever  110  and leg  211  prevents distal end  108   c  from moving away from gear  102  (gear  506  in FIG.  13 ), however distal end  108   c  is permitted to contact, or at least to more closely approach, the mentioned shoulder between cavities  109  and  111 . 
     In operation, when swing arm  22  enters slot  20   b  to close the restraining space, gears  102 , 104  and  106  begin to rotate as soon as teeth  16   a  on swing arm  22  contacts gear  104 . It is clear, that the rotation of swing arm  22  in one direction, causes gears  102  and  104  to rotate in the opposite direction which in turn causes gear  106  to rotate in the same direction as swing arm  22 . It is equally clear, that gear  102  (gear  506  in FIG.  13 ), in order to rotate at all, must rotate past proximal end  108   a  which, therefor, requires distal end  108   c  to move linearly against and compress spring  118 . The wedge shape of proximal end  108   a  permits a tooth of gear  102  (gear  506  in FIG.  13 ), while moving in the closing rotational direction, which in the specific example of FIG. 3 is clockwise, (counter clockwise in FIG. 13) to rotate against the slanted side (and away from the flat side) of the wedge. It is believed that the slanted side of the wedge operates to convert the closing rotational motion of the tooth into a linear motion which acts to compress spring  118  with the result that the pushing tooth slides past the proximal end  108   a  which causes proximal end  108   a  to clear the pushing tooth. At the point of clearance spring  118  linearly expands to cause proximal end  108   a  to immediately enter the valley between the pushing tooth and the next tooth in succession. The action just described is then repeated. 
     It is believed that the slanted side of the wedge will operate more efficiently if the slant is in fact concave as shown in FIG.  3 . Accordingly, in a preferred embodiment, the slanted side of the wedge is concave. 
     It is clearly important to the operation of the invention that the slanted side of the wedge be in contact with a tooth rotating in the closing direction. Thus, linear rotation of control pin  108  in cavity  111  would interrupt the required contact. The above described rectangular cross sections of control pin  108  in the disclosed rectangular slots prevents the linear rotation of control pin  108 . 
     The opening rotational directions of the swing arm and the gears are all opposite to the disclosed closing rotational directions. Thus, the restraining space cannot be opened when the handcuff is configured as shown in FIG. 3 because a tooth of gear  102  (gear  506  in FIG.  13 ) moving in the opening rotational direction contacts the flat side of the wedge and a linear motion is not produced in control pin  108  to compress spring  118 . Accordingly, proximal end  108   a  does not move and swing arm  22  does not move. 
     To open the restraining space, the handcuff must be configured as shown in FIG. 2 wherein control spring  118  is compressed by operation of the locking mechanism of this invention to linearly further move distal end  108   c  into cavity  109  and to linearly move proximal end  108   a  out of cavity  101  (cavity  505  in FIG. 13) and into cavity  111  to a position where it cannot contact any tooth of gear  102  (gear  506  in FIG.  13 ). It is to be understood that placing the handcuff in the opening position shown in FIG. 2 enables movement of the gears and swing arm in any rotational direction. However, the gears must rotate to enable swing arm  22  to move in any direction. 
     To prevent any rotation of the gears in any direction the locking mechanism is configured in the locked position as shown in FIG.  4 . It is to be understood that the swing arm, if not engaged with a tooth of a gear as shown in FIG. 4, can move until it contacts a gear tooth, then it cannot move. The locked position, as shown in FIG. 4, resists any force placed by a tooth of gear  102  (gear  506  in FIG. 13) moving in the closing rotational direction on the slant side of the wedge of proximal end  108   a  to compress spring  118 . 
     Referring now to FIGS. 2-5, the locking mechanism of this invention, shown in cavity  107  of housing block  20 , is comprised of lever  110 , yoke  204 , yoke axle  205  and detent assembly  206 . 
     Yoke  204  is in the shape of an oval plate having a closed end and an open end. The closed end, which is pierced by hole  210 , is referred to as the axle end of yoke  204 . The open end is linearly spaced apart from the closed end. The open end, referred to as the forked end of yoke  204 , has first leg  211  on one side of opening  213  and second leg  212  on the opposite side of opening  213  wherein second leg  212  is spaced apart from and, preferably, parallel to first leg  211 . 
     Yoke  204  contains two semi-circular grooves  207  and  208  on the outer edge of the axle end. The position and size of each of grooves  207  and  208 , referred to herein as scallops, are significant and shall be further discussed herein below. 
     Yoke  204  further contains three linear pockets  214 ,  215  and  216  formed on the surface of hole  210 . Each of pockets  214 ,  215  and  216  is parallel to the axis and spaced at 120° intervals around the surface of hole  210 . There must be at least one linear pocket. Multiple pockets can be spaced at intervals greater or less than the mentioned 120° intervals. 
     Hole  210  of yoke  204  is rotatably mounted on yoke axle  205  which is perpendicularly fixed to cheek plate  7   a . In this regard, axle  205  press fits in hole  217  in cheek plate  7   a  and yoke  204  rotates around axle  205  in a plane parallel to cheek plates  6   a  and  7   a . It is understood that axle  205  is fixed and does not rotate in hole  217 . 
     Lever  110  is a rod which is perpendicularly and rigidly attached to shaft  108   b  of control pin  108  at a point intermediate proximal end  108   a  and distal end  108   c . Lever  110  projects into cavity  107  and opening  213  of yoke  204  between first leg  211 , on one side of opening  213 , and second leg  212 , on the opposite side of opening  213 . The respective lengths of lever  110 , leg  211  and leg  212  are adjusted to enable leg  211  to contact lever  110  upon rotation of yoke  204  around axle  205  toward proximal end  108   a , as shown in FIG. 4, and to enable leg  212  to contact lever  110  upon rotation of yoke  204  around axle  205  toward distal end  108   c , as shown in FIG.  2 . 
     Referring to FIGS. 2,  3 ,  4  and  5 , detent assembly  206  controls the position of yoke  204  relative to axle  205  in cavity  107 . Assembly  206 , comprised of spring  218  and detent ball  219 , is housed in notch  107   a  in housing block  20 . Notch  107   a  opens into cavity  107  at a point adjacent to the axle end of yoke  204 . One end of spring  218 , is in linear contact with block  20  at the end of notch  107   a , the other end of spring  218  is in linear contact with the exterior surface of ball  219 , which extends into cavity  107  and contacts the axle end of yoke  204 . Compressive forces developed in spring  218  between housing block  20  in notch  107   a  and the axle end of yoke  204  in cavity  107  act to maintain detent assembly  206  in place. 
     As mentioned, one end of spring  218  is in linear contact with the exterior surface of ball  219 . The outside diameter of spring  218  is less than the diameter of ball  219 , accordingly, spring  218  does not envelop ball  219 , but merely exerts a biasing force against ball  219 . Detent ball  219  is equipped with radial projection  220  whose diameter is, less than the inside diameter of spring  218 . Projection  220  is slidably inserted into the interior of spring  218  to help maintain the contact between the exterior surface of ball  219  and spring  218 . 
     The position and size of each of scallops  207  and  208  (in FIG. 13 the scallops are reversed) on the outer edge of the axle end of yoke  204  was earlier mentioned to be of significance. In this regard, each of scallops  207  and  208  are elongated, curved, surfaces which are sized to receive and hold at least a portion of the curved surface of ball  219 . Furthermore, scallop  207  is positioned on yoke  204  so that yoke  204  is placed in the opening position, as shown in FIG. 3, when ball  219  is held in scallop  207 . Still further, scallop  208  is positioned on yoke  204  so that yoke  204  is placed in the locked position, as shown in FIG. 4, when ball  219  is held in scallop  208 . 
     Keyway  222 , shown in FIGS. 1 and 12, is a hollow, cylindrical structure having an interior axial hole  223  drilled from top surface  224  to bottom surface  225 , wherein the diameter of hole  223  is greater than the diameter of yoke axle  205 . Keyway  222  has a first exterior diameter  226  and a second exterior diameter  227  which is greater than diameter  226 . Exterior diameter  226 , which is the diameter of bottom surface  225 , extends from bottom surface  225  to a position intermediate bottom surface  225  and top surface  224 . Shoulder  228  is formed in keyway  222  where diameter  226  ends and diameter  227  begins. The distance from bottom surface  225  to shoulder  228  is preferably equal to the thickness of cheek plate  6   a . Diameter  229  of top surface  224  is greater than the diameter of axial hole  223  and, preferably, less than exterior diameter  227 . The distance from top surface  224  to shoulder  228  is a matter of personal preference. Beveled surface  230  extends from surface  224  to a point on the surface generated by diameter  227  above shoulder  228 . The length of surface  230  is a matter of personal preference. 
     Keyway  222  is supported on the outside surface of cheek plate  6   a . In this connection, yoke axle  205  extends through axial hole  223 . The cylindrical portion of keyway  222  having exterior diameter  226  is pressed into a hole in cheek plate  6   a , the diameter of which is approximately equal to exterior diameter  226  until shoulder  228  contacts the exterior surface of cheek plate  6   a . An annulus space  231  is created between the exterior curved surface of yoke axle  205  and the surface of axial hole  223 . 
     The rotation of yoke  204  around yoke axle  205  is effected by use of key  300 . Referring to FIGS. 1,  4 ,  10 ,  11  and  12 , key  300  is comprised of barrel  302  and handle  304 . Barrel  302  is a hollow cylinder having an inside diameter greater than the diameter of yoke axle  205  and an outside diameter less than the diameter of hole  223  in keyway  222 . The thickness of barrel  302  is, thus, less than the width of annulus space  231  between the exterior curved surface of yoke axle  205  and the surface of axial hole  223 . 
     Barrel  302  has a handle end and a tang end. Handle  304  is rigidly connected to the handle end of barrel  302 . As shown in FIG. 1, handle  304  is a disc which is radially connected to and aligned with the linear axis of barrel  302 . The particular shape of handle  304  is a matter of personal preference, but it must be of a size sufficient to enable it to be firmly grasped between the thumb and index finger of an adult person. Also as shown in FIG. 1, handle  304  is pierced by hole  306 . Hole  306  can be employed by the user as a means of fastening key  300  to a suitable ring or lanyard. 
     The tang end of barrel  302  is equipped with three elongated tangs  308 ,  310  and  312  which are rigidly attached to and linearly extend from the tang end of barrel  302  parallel to the linear axis of barrel  302 . Each of tangs  308 ,  310  and  312  are appropriately spaced around barrel  302  to place them in simultaneous alignment with pockets  214 ,  215  and  216  formed on the surface of hole  210  in yoke  204  and are adapted and shaped to be slidably inserted into pockets  214 ,  215  and  216 . 
     Barrel  302  must be of length at least sufficient to enable yoke axle  205  to fit within the hollow interior of barrel  302  and tangs  308 ,  310  and  312  to fit within pockets  214 ,  215  and  216 . 
     Operation of the Invention 
     The basic operation and cooperation of the various elements of the operating mechanism and the locking mechanism of this invention has been discussed. It is left to be stated that the tangs of key  300  are placed in the pockets of yoke  204 . Key  300  is then turned with a force sufficient to cause pin  108 , via lever  110  and leg  212 , to overcome the biasing effects of spring  118  in cavity  109  and spring  218  in notch  107   a  to move ball  219  to scallop  207  to thereby place handcuff  2  in closing position as shown in FIG.  3 . At that point, free end  10  of swing arm  22  is rotated with sufficient force into slot  20   b  to compress spring  118  to cause teeth  16   a  to at least engage the teeth of gear  104  and preferably the teeth of gears  104  and  102 . 
     Thereafter, with the tangs of key  300  in the pockets of yoke  204 , key  300  is turned with a force sufficient to cause pin  108 , via lever  110  and leg  211 , to overcome the biasing effects of spring  218  in notch  107   a  to move ball  219  to scallop  208  to thereby place handcuff  2  in locked position as shown in FIG.  4 . 
     Thereafter, with the tangs of key  300  in the pockets of yoke  204 , key  300  is turned with a force sufficient to cause pin  108 , via lever  110  and leg  212 , to overcome the biasing effects of spring  118  in cavity  109  and spring  218  in notch  107   a  to move ball  219  past scallops  208  and  207  to a position on the edge of the axle end of yoke  204  to thereby place handcuff  2  in opening position as shown in FIG.  2 . Then, while using key  300  to maintain the opening position, free end  10  of swing arm  22 ,is rotated out of slot  20   b  to a point that no tooth  16   a  on swing arm  22  is in contact with any tooth on gear  104 .