CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Canadian Patent Application No. 3,176,068, filed on September 26, 2022, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

[0002] The present application relates to a smart double-lock handcuff.

BACKGROUND

[0003] Handcuffs often have a double-lock mechanism.

[0004] FIGS. 1 to 6 illustrate an example prior art handcuff 100 that has a double-lock mechanism. The handcuff 100 may be similar to that described in U.S. Patent No. 4,287,731. It will be appreciated that only one handcuff is shown and that handcuffs typically include a pair of handcuffs chained one to the other.

[0005] As shown, the handcuff 100 comprises a generally arcuate jaw 102 having ratchetlike teeth 104 at one end and pivotally connected at its opposite end between cheeks 106, 108.

[0006] The cheeks 106, 108 terminate at their opposite ends in heads 110, 112, respectively, which form part of a lock assembly 114. The lock assembly 114 includes a frame 116 disposed between the heads 110, 112. Put another way, the heads 110, 112 straddle the frame 116.

[0007] The lock assembly 114 includes a lock bar 118 (also referred to as a bolt) and a lock spring 120 (also referred to as a bolt spring) that are disposed within a cavity of the lock assembly 114.

[0008] As best shown in FIG. 4, the lock bar 118 comprises an elongated shank 122, a head 124 having teeth 126 for engaging the teeth 104 of the jaw 102, and an enlarged generally circular hub 128 at its end remote from the head 124. The lock bar 118 is pivotally secured to the cheeks 106, 108 and the frame 116 by a stud 132 secured between the heads 110, 112 and a shaped recess 134 on the frame 116. The stud 132 extends below the hub 128 and provides a pivotal support therefor. The recess 134 is defined by a circular wall portion which lies on the opposite side of the hub 128 from the stud 132. As such, the stud 132 and the wall portion define a bearing for the hub 128 and about which the lock bar 118 pivots. The head 124 of the lock bar 118 carries a shoulder 136 adjacent its forward edge. In addition, upper surfaces of the lock bar 118 have spaced detents 138 and 140.

[0009] As best shown in FIG. 5, the lock spring 120 comprises an elongated strip of metal reversely formed, e.g., bent, intermediate its ends to provide first and second spring leg portions 142 and 144, respectively. The lock spring 120 is disposed within the cavity such that the first spring leg portion 142 bears against shank 122 of the lock bar 118 to bias it for pivotal movement in a clockwise direction tending to move the bolt into a locking position with the teeth 126 engaging the teeth 104 of the jaw 102. The first spring leg portion 142 is bent to define tab 146 which cooperates with detents 138 and 140 to prevent linear movement of the lock spring 120 except when the lock spring 120 is moved by a key. The second spring leg portion 144 bears against the base of the cavity. The second spring leg portion 144 also carried a detent 148 for locking the lock bar 118 in a locked position. The second spring leg portion 144 is formed, e.g., bent, intermediate its length to provide a generally U-shaped spring leaf portion extending toward first spring leg portion 142 for engagement with the top of head 124. The distal end or tip of second spring leg portion 144 is formed, e.g., bent, to terminate in a shoulder or flange 150 and which flange 150 extends in a direction toward first spring leg portion 142.

[0010] The lock spring 120 is carried for linear sliding movement lengthwise within the cavity between first and second positions, respectively. Particularly, the first spring leg portion 142 is adapted to slide along the upper face of shank 122 of the lock bar 118. The tab 146 engages detent 138 in the first position to prevent linear sliding movement of the lock spring without the handcuff key as by application of impact forces to the handcuff. The tab 146 also cooperates with detent 140 in the second position for the same purpose. In this manner, the lock spring 120 may be moved only by the key. The second spring leg portion 144 is slidable along the flat underside of frame, the opposite ends of lock spring 120 butting the ends of frame and defining the end limits of its linear displacement.

[0011] As shown in FIG. 6, a key 200 is provided that comprises a shank 202 with a radial projection 204 at one end and an axial projection or pin 206 at its opposite end. The end of the key 200 carrying the projection 204 is axially recessed for engagement about a pin 210. The pin 210 is secured to head 110 and projects across cavity into a key slot 212 formed in head 110. The head 110 has an elongated key slot 214 therethrough adjacent the opposite end of the cavity.

[0012] In order to close handcuff 100 hereof, the jaw 102 is moved such that its free end is moved between cheeks 106 and 108. The teeth 104 of the jaw 102 slide past the teeth 126 of the lock bar 118 in a ratchet-like manner. When the handcuff 100 is fully closed, the lock bar 118 is biased by the lock spring 120 to maintain the teeth 126 of the lock bar 118 engaged with the teeth 104 of the jaw 102 thus locking the handcuff 100 in a closed position and preventing movement of the jaw 102 away from the cheeks 106 and 109. This action provides a single-lock for the handcuff 100.

[0013] To double-lock the handcuff 100 in the closed position, the lock spring 120 is linearly displaced, from a first position to a second position illustrated. To linearly displace the lock spring 120, the pin 206 on the key 200 is inserted into the key slot 214 to engage behind the lock spring 120. By translating the key 200, for example from left to right in the key slot 214, the lock spring 120 is displaced linearly along the cavity into a lock position where the detent 148 is located in registry with or opposite the head 124 of the lock bar 118. This prevents the lock bar 118 from pivoting toward an unlocked position with the teeth 126 disengaged from the teeth 104 while simultaneously the detent 148 prevents the lock bar 118 from pivoting from its locking position vis-a-vis the jaw 102 toward its unlocked position. As such, the lock spring 120 serves as a double-lock for the handcuff 100.

[0014] To unlock the double-lock handcuff 100 and enable the jaw 102 and the cheeks 106 and 108 to pivot in a direction away from one another, the key 200 is inserted into the key slot 212. By rotating the key 200, for example in a counter clockwise direction, the projection 204 engages the flange 150 at the end of the second spring leg portion 144. Upon continued rotation of the key 200 in the counter clockwise direction, the lock spring 120 is linearly displaced, for example from right to left. The linear displacement misaligns the detent 148 with the head 124 of the lock bar 118 such that the head 124 registers with the space along the second spring leg portion 144 between the detent 148 and the flange 150. The bias of the lock spring 120 urges the lock bar 118 into engagement with the jaw 102 to maintain the handcuff in the locked condition. Once the lock spring 120 is displaced to the left, the key 200 is rotated in the opposite direction, for example clockwise, to bring the projection 204 into engagement with the shoulder 136 on the head 124. Continued rotation of the key 200 in the clockwise direction lifts or pivots the lock bar 118 to remove the teeth 126 from engagement with the teeth 104. Thus, the jaw 102 is free for movement away from the cheeks 106, 108 whereby the handcuff 100 may be opened. It will be appreciated that in the course of double-locking and unlocking the bolt spring, the key exerts sufficient force to overcome frictional resistance.

[0015] It will be appreciated that double-lock mechanisms are difficult to activate in cases of active or violent resistance and as such handcuffs that have the double-lock mechanism pose the risk of serious injury. For example, when the handcuff 100 is closed without the double-lock engaged, the handcuff 100 can only tighten and the jaw 102 can only be released using the key 200. This self-tightening of the handcuff 100 may cause a serious injury such as for example an injury referred to as handcuff neuropathy which is a compression of the superficial radial nerve.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Embodiments are described in detail below, with reference to the following drawings:

[0017] FIG. 1 is an isometric view of a prior art double-lock handcuff;

[0018] FIG. 2 is an exploded view of the prior art double-lock handcuff of FIG. 1;

[0019] FIG. 3 is a cross-sectional view of the prior art double-lock handcuff of FIG. 1; [0020] FIG. 4 is a side view of a lock bar forming part of the double-lock handcuff of FIG.

1;

[0021] FIG. 5 is side view of a lock spring forming part of the double-lock handcuff of FIG. 1;

[0022] FIG. 6 is a side view of a key forming part of the double-lock handcuff of FIG. 1;

[0023] FIG. 7 is an isometric view of a smart double-lock handcuff according to an embodiment;

[0024] FIG. 8 is an exploded view of the smart double-lock handcuff of FIG. 7 according to an embodiment;

[0025] FIG. 9 is a cross-sectional view of the smart double-lock handcuff of FIG. 7 according to an embodiment;

[0026] FIG. 10 is a side view of the smart double-lock handcuff of FIG. 7 according to an embodiment;

[0027] FIG. 11 is a high-level schematic diagram of components of the smart double-lock handcuff of FIG. 7 according to an embodiment; and

[0028] FIG. 12 is a flowchart showing operations performed in activating a double-lock of the double-lock handcuff of FIG. 7 according to an embodiment.

[0029] Like reference numerals are used in the drawings to denote like elements and features.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

[0030] Accordingly, in one aspect there is provided a smart double-lock handcuff comprising a spring for activating a double-lock of the handcuff, the spring positioned within a cavity of a lock assembly of the handcuff adjacent to a lock spring that is movable between an unlocked position and a locked position; an actuator positioned to release the spring; and a microcontroller coupled to the actuator, the microcontroller including executable-instructions that, when executed, cause the microcontroller to perform operations to communicate signals to activate the actuator to release the spring to cause the lock spring to translate within the cavity from the unlocked position to the locked position to activate the double-lock.

[0031] In one or more embodiments, the lock spring includes a first spring leg portion that defines a tab that engages with a protuberance on a lock bar of the lock assembly to prevent linear movement of the lock spring from the unlocked position to the locked position.

[0032] In one or more embodiments, the spring is compressed by the lock spring when the tab of the first spring leg portion is engaged with the protuberance on the lock bar.

[0033] In one or more embodiments, the lock spring is in the unlocked position when the tab is engaged with the protuberance on the lock bar.

[0034] In one or more embodiments, the spring is compressed by the lock spring when the lock spring is in the unlocked position.

[0035] In one or more embodiments, the smart double-lock handcuff further comprises a lever connected at a first end to the actuator and having a second end positioned adjacent to the first spring leg portion of the lock spring, wherein activation of the actuator causes the second end of the lever to lift the first spring leg portion to disengage the tab of the first spring leg portion from the protuberance on the lock bar to release the compressed spring.

[0036] In one or more embodiments, the smart double-lock handcuff further comprises a plurality of pressure sensors positioned on a cheek of the handcuff; wherein the executableinstructions, when executed, further cause the microcontroller to obtain sensor data from the plurality of the pressure sensors; analyze the sensor data to determine an amount of pressure; determine that the amount of pressure is greater than a threshold; and responsive to determining that the amount of pressure is greater than the threshold, communicate the signals to activate the actuator. [0037] In one or more embodiments, the executable-instructions, when executed, further cause the microcontroller to analyze the sensor data to determine a number of the pressure sensors that have sensed pressure; and determine, based on the number of the pressure sensors that have sensed pressure, the presence of a wrist.

[0038] In one or more embodiments, the executable-instructions, when executed, further cause the microcontroller to analyze the sensor data to determine a number of the pressure sensors that have sensed pressure; determine, based on the number of the pressure sensors that have sensed pressure, that a wrist is not present; and power down.

[0039] In one or more embodiments, the smart double-lock handcuff further comprises a plurality of position sensors positioned within the cavity of the lock assembly to determine activation of a single-lock of the handcuff.

[0040] In one or more embodiments, the executable-instructions, when executed, further cause the microcontroller to receive, from at least one of the position sensors, sensor data indicating activation of the single-lock of the handcuff; and responsive to receiving the sensor data indicating activation of the single-lock of the handcuff power on the microcontroller; and obtain the sensor data from the pressure sensors and the position sensors.

[0041] In one or more embodiments, the smart double-lock handcuff further comprises a plurality of pressure sensors positioned on a cheek of the handcuff; a plurality of position sensors positioned within the cavity of the lock assembly to determine a ratchet position; wherein the executable-instructions, when executed, further cause the microcontroller to obtain sensor data from the plurality of the pressure sensors and the plurality of the position sensors; determine, based on the sensor data, that the double-lock is to be activated; and communicate the signals to activate the actuator.

[0042] In one or more embodiments, when determining, based on the sensor data, that the double-lock is to be activated, the executable-instructions, when executed, further cause the microcontroller to analyze the sensor data to determine an amount of pressure and the ratchet position; and determine, based on the amount of pressure and the ratchet position, that the doublelock is to be activated.

[0043] In one or more embodiments, the double-lock is activated by the microcontroller but is not deactivated by the microcontroller.

[0044] In one or more embodiments, the double-lock is deactivated using a key that causes the lock spring to translate within the cavity from the locked position to the unlocked position.

[0045] In one or more embodiments, the microcontroller is coupled to a power source and the double-lock is activatable using a key when the power source is discharged.

[0046] According to another aspect there is provided a pair of handcuffs comprising a first and a second handcuff as described herein and a chain connecting the first handcuff and the second handcuff to one another.

[0047] Other aspects and features of the present application will be understood by those of ordinary skill in the art from a review of the following description of examples in conjunction with the accompanying figures.

[0048] In the present application, the term “and/or” is intended to cover all possible combinations and sub-combinations of the listed elements, including any one of the listed elements alone, any sub-combination, or all of the elements, and without necessarily excluding additional elements.

[0049] In the present application, the phrase “at least one of .. .or.. .” is intended to cover any one or more of the listed elements, including any one of the listed elements alone, any subcombination, or all of the elements, without necessarily excluding any additional elements, and without necessarily requiring all of the elements.

[0050] In the present application, examples involving a microcontroller, aspects of the disclosure transform the microcontroller into a special-purpose microcontroller when configured to execute the instructions described herein. [0051] Turning to FIGS. 7 to 10, a smart double-lock handcuff 700 is shown. It will be appreciated that only one handcuff is shown and that handcuffs typically include a pair of handcuffs chained one to the other.

[0052] The smart double-lock handcuff 700 includes various components that may be engaged to activate a single-lock for the handcuff 700. The various components are generally similar to those described herein with reference to FIGS. 1 to 6. Components of the handcuff 700 that are similar to components of the handcuff 100 will be identified using like reference characters with a “700” used for clarity.

[0053] As mentioned, prior art handcuffs that include that double-lock mechanisms are difficult to activate in cases of active or violent resistance. The handcuff 700 addresses problems of these prior art handcuffs in manners described below.

[0054] The handcuff 700 includes a double-lock mechanism that comprises an electronic assembly 800 disposed within a cavity of a lock assembly 714. In one or more embodiments, the electronic assembly 800 comprises a microcontroller, an actuator and a power supply used to provide power to the microcontroller. As will be described in more detail below, the electronic assembly 800 includes components that may perform operations to activate the double-lock.

[0055] In one or more embodiments the lock bar 718 and the lock spring 720 are generally similar to the lock bar 118 and the lock spring 120 described herein, with the following exceptions. The lock bar 718 of the handcuff 700 comprises a protuberance 810 extending from a top surface thereon. The protuberance 810 may be generally frustoconical shaped. The first spring leg portion 742 of the lock spring 720 defines a tab 820 that is engaged with the protuberance 810 when the lock spring 720 is in an unlocked position (shown in FIG. 9). Put another way, the tab 820 is in contact with the protuberance 810 and in this manner the lock bar 718 holds the lock spring 720 in the unlocked position.

[0056] The double-lock mechanism of the handcuff 700 comprises a spring 830 that is positioned within the cavity of the lock assembly 714 adjacent to the lock spring 720. Specifically, the spring 830 is positioned adjacent to a portion of the lock spring 720 that is intermediate the first spring leg portion 742 and the second spring leg portion 744. The spring 830 is held in a compressed state by the lock spring 720 when the lock spring 720 is in the unlocked position (shown in FIG. 9).

[0057] As mentioned, the electronic assembly 800 includes components that may perform operations to activate the double-lock. In one or more embodiments, the actuator of the electronic assembly 800 is connected to a first end of a lever 840. A second end of the lever 840 is positioned adjacent to the first spring leg portion 742 of the lock spring. As will be described in more detail, the microcontroller may perform operations to activate the actuator to release the spring from the compressed state. For example, in one or more embodiments, the actuator may be activated to move the lever 840 and in response the second end of the lever 840 may lift the first spring leg portion 742 of the lock spring 720 to disengage the tab 820 from the protuberance 810 on the lock bar 718. This causes the spring 830 to release and in response the spring 830 causes the lock spring 720 to translate within the cavity from the unlocked position to a locked position and this activates the double-lock.

[0058] In one or more embodiments, as best shown in FIG. 10, the handcuff 700 may include a plurality of pressure sensors 1000 that are positioned on one of the cheeks 106, 108. As will be described in more detail below, the pressure sensors 1000 are coupled to the electronic assembly 800 and are used to determine an amount of pressure between the handcuff 700 and a wrist of a wearer of the handcuff 700.

[0059] The handcuff 700 includes a plurality of position sensors 1010 that are positioned within the cavity at a location adjacent to the teeth 126 of the lock bar 118. As will be described in more detail below, the position sensors 1010 are coupled to the electronic assembly 800 and are used to determine a position of the jaw 102 relative to the lock bar 118 to determine when the teeth 126 of the lock bar 118 are engaged with the teeth 104 of the jaw 102. This position may be referred to as a ratchet position. The position sensors 1010 may additionally or alternatively be used to determine activation of a single-lock of the handcuff 700. [0060] Turning now to FIG. 11 , a high-level schematic diagram of components of the smart double-lock handcuff 700 is shown. As can be seen, the electronic assembly 800, specifically the microcontroller, is coupled to the actuator 1100, the pressure sensors 1000 and the position sensors 1010. The electronic assembly 800 may receive sensor data from the pressure sensors 1000 and the position sensors 1010 and may analyze the sensor data to perform operations to activate the double-lock of the handcuff 700.

[0061] FIG. 12 is a flowchart showing operations performed in activating a double-lock of the handcuff. The operations may be included in a method 1200 which may be performed by the microcontroller of the electronic assembly 800. For example, computer-executable instructions stored in memory of the microcontroller may, when executed, configure the microcontroller to perform the method 1200 or a portion thereof. It will be appreciated that the microcontroller may offload some of the operations.

[0062] The method 1200 includes receiving a signal indicating activation of the first lock (step 1210).

[0063] In one or more embodiments, the microcontroller may remain powered off or in sleep-mode until activation of the first lock. In these embodiments, the position sensors 1010 may include push button switches. The position sensors 1010 may be activated in response to the jaw 102 being moved between the cheeks 106, 108. In response, the position sensors 1010 may send a signal to power on or activate the microcontroller.

[0064] In one or more embodiments, the microcontroller may operate in a low-power mode. In these embodiments, the position sensors 1010 may include proximity sensors. The proximity sensors may obtain sensor data and may communicate the sensor data to the microcontroller. The microcontroller may analyze the sensor data to identify that the jaw 102 has been moved between the cheeks 106, 108. [0065] Activation of the first (or single-lock) is determined. It will be appreciated that in these embodiments, activation of the first (or single-lock) may additionally or alternatively include identifying when the teeth 126 of the lock bar 118 are engaged with the teeth 104 of the jaw 102.

[0066] The method 1200 includes obtaining sensor data (step 1220).

[0067] The sensor data may include pressure sensor data and/or position sensor data received from the pressure sensors 1000 and the position sensors 1010.

[0068] In one or more embodiments, in response to activation of the first (or single-lock), the microcontroller polls the pressure sensors to obtain pressure sensor data therefrom. For example, the microcontroller may request pressure sensor data from the pressure sensors at a set frequency which may be, for example, every microsecond. In one or more embodiments, the microcontroller may continuously obtain pressure sensor data from the pressure sensors.

[0069] The pressure sensor data obtained from the pressure sensors is analyzed to determine an amount of pressure between the handcuff 700 and a wrist of a wearer of the handcuff 700.

[0070] In one or more embodiments, the pressure sensor data obtained from the pressure sensors may be analyzed to determine a presence of a wrist. For example, the microcontroller may determine that a small number of the pressure sensors, for example only one of the pressure sensors, have communicated pressure sensor data that identifies an amount of pressure. As such, the microcontroller may determine that the pressure is not from a wrist but rather from some other source such as for example a police officer’s finger and as such the microcontroller does not perform additional operations under the presence of a wrist is determined. In this manner, the pressure sensor data may be used to first determine the presence of the wrist and then to determine an amount of pressure between the handcuff 700 and the wrist.

[0071] In one or more embodiments, in response to activation of the first (or single-lock), the microcontroller may poll the pressure sensors to obtain pressure sensor data therefrom and may determine that none of the pressure sensors have identified pressure. As such, the microcontroller may be programmed to power off or enter sleep-mode if no pressure is identified for a period of time such as for example for thirty (30) seconds. This may help to preserve power of the power supply.

[0072] In one or more embodiments, in response to activation of the first (or single-lock), the microcontroller may additionally or alternatively poll the position sensors to obtain position sensor data therefrom. For example, the microcontroller may request position sensor data from the position sensors at a set frequency which may be, for example, every microsecond. In one or more embodiments, the microcontroller may continuously obtain position sensor data from the pressure sensors.

[0073] The microcontroller may analyze the position sensor data to determine a ratchet position. For example, the position sensor data may be analyzed to determine how many teeth 104 of the jaw 102 are engaged with the teeth 126 of the lock bar 118 and this may be used to determine the ratchet position.

[0074] The method 1200 includes determining whether or not to activate the double-lock (step 1230).

[0075] In one or more embodiments, determining whether or not to activate the doublelock may include comparing the amount of pressure to a threshold. The threshold may include a predefined threshold. The threshold may be defined to indicate that the handcuff 700 is in contact with the wrist and to ensure that the handcuff 700 is not so tight that the wearer of the handcuff 700 is at risk for injury.

[0076] In one or more embodiments, determining whether or not to activate the doublelock may be based on both the position sensor data and the pressure sensor data. For example, sensor data may be previously obtained and this previous sensor data may be used to determine when to activate the double-lock. The previous sensor data may include different amounts of pressure and different ratchet positions that were previously determined to be acceptable. The previous sensor data may have been obtained from a variety of wrist sizes. In these embodiments, the microcontroller may monitor both the ratchet position and the amount of pressure being applied to the wrist and may determine when to activate the double-lock. It will be appreciated that the previous sensor data may be stored or programmed onto the microcontroller in manners similar to a lookup table.

[0077] When it is determined not to activate the double-lock, the method returns to step 1220 where the microcontroller continues to obtain sensor data.

[0078] Responsive to determining to activate the double-lock, the method 1200 includes sending a signal to activate the double-lock (step 1240).

[0079] In one or more embodiments, the microcontroller may communicate signals to activate the actuator to release the spring 830 to cause the lock spring 720 to translate within the cavity from the unlocked position to the locked position to activate the double-lock.

[0080] In one or more embodiments, where the actuator is connected to the lever 840, the microcontroller may communicate signals to activate the actuator which may cause the second end of the lever 840 to lift the first spring leg portion 742 of the lock spring 720 and this may cause the tab 820 to disengage from the protuberance 810 of the lock bar 718. In response, the compressed spring 830 may be released and may cause the lock spring 720 to translate within the cavity from the unlocked position to the locked position to activate the double-lock. In one or more embodiments, when the lock spring 720 in the locked position, the lock bar 118 is prevented from pivoting toward an unlocked position with the teeth 126 disengaged from the teeth 104 while simultaneously the protuberance 810 prevents the lock bar 718 from translating from the locked position to the unlocked position. In this manner, the actuator is used to release the compressed spring 830 to activate the double-lock.

[0081] In one or more embodiments, the handcuff 700 may only be locked using the various electronic components described herein. Put another way, the handcuff 700 may not be unlocked using the various electronic components described herein. Rather, the handcuff 700 can only be unlocked using a key and this may be done in manners similar to that described herein with reference to the handcuff 100. For example, rotation of the key in a particular direction may cause the lock spring 720 to translate from the locked position to the unlocked position which in turn compresses the spring 830 and causes the tab 820 to engage the protuberance 810 on the lock bar 718.

[0082] It will be appreciated that in one or more embodiments, the double-lock of the handcuff 700 may still be engaged manually using a key. For example, in embodiments where the power supply of the electronic assembly 800 is discharged, it may be required to engage the double-lock manually.

[0083] In manners described herein, the handcuff 700 automatically engages the doublelock and this prevents further tightening of the handcuff 700 once the double-lock is engaged. The risk of injury to the wearer of the handcuff 700 is lowered as the double-lock is automatically engaged in response to sufficient pressure being applied to the wrist of the wearer by the handcuff 700.

[0084] The methods described herein may be modified and/or operations of such methods combined to provide other methods.

[0085] As noted, certain adaptations and modifications of the described embodiments can be made. Therefore, the herein discussed embodiments are considered to be illustrative and not restrictive.