Shape memory alloy locking and closure system

Abstract

Lockable locking device (10), comprising: a housing (12) which defines a cavity (14) therein and has a central longitudinal axis (16); a piston (22) arranged within the cavity (14) and having a first end (24) and a second end (26) spaced apart from the first end (24), wherein the piston (22) is displaceable with respect to the housing (12) along the central longitudinal axis (16) between: an open position (32) in which the second end (26) is arranged within the cavity (14); and a closed position (34) in which the second end (26) protrudes from the cavity (14); a ring-shaped rotary actuator (60) arranged along the central longitudinal axis (16) and configured to rotate the piston (22) about the central longitudinal axis (16); an annular locking device (62) that rests against the annular rotary actuator (60) and is displaceable between: an unlocked state (72) in which the annular locking device (62) is positioned about the central longitudinal axis (16) so that the piston (22) is displaceable between the open position (32) and the closed position (34); and a locked state (74) in which the annular locking device (62) is positioned about the central longitudinal axis (16) so that the piston (22) is not displaceable between the open position (32) and the closed position (34); a first element (166) formed from a first shape memory alloy which is switchable between a first austenite crystallographic phase and a first martensite crystallographic phase in response to a first activation signal (176), wherein the first element (166) has a first end fixed relative to the case (12) and a second end fixed relative to the case (12) such that the first end of the first element (166) is in a fixed position relative to the second end of the first element (166); a second element (168) functionally connected to the annular locking mechanism (62) and formed from a second shape memory alloy which is switchable between a second austenite crystallographic phase and a second martensite crystallographic phase in response to a second activation signal (178), wherein the second element (168) has a first end fixed relative to the housing (12) and a second end fixed relative to the housing (12) such that the first end of the second element (168) is in a fixed position relative to the second end of the second element (168); a force transmission mechanism functionally connected to the first element (166), the second element (168) and the annular lock (62), wherein the force transmission mechanism is configured to transfer the annular lock (62) from the unlocked state (72) to the locked state (74) in response to the first activation signal (176), wherein the force transmission mechanism is further configured to transfer the annular lock (62) from the locked state (74) to the unlocked state (72) in response to the second activation signal (178); wherein the force transmission mechanism comprises a slide (150) configured to move relative to the housing (12), wherein the slide (150) is forced by the first element (166) to move in a first linear direction in response to the first activation signal (176), and wherein the slide (150) is forced by the second element (168) to move in a second linear direction opposite the first linear direction in response to the second activation signal (178); wherein the power transmission mechanism further comprises a lever (142) rotatable about a pivot axis (158) fixed relative to the housing (12), wherein the lever (142) is forced by the slide (150) to rotate in a first direction of rotation in response to the first activation signal (176), and wherein the lever (142) is forced by the slide (150) to rotate in a second direction of rotation opposite the first direction of rotation in response to the second activation signal (178); wherein the lever (142) is functionally coupled to the ring-shaped locking device (62); and wherein the lever (142) is functionally coupled to the annular locking device (62) by a compliant coupling which is configured to deform elastically when the annular locking device (62) is prevented from moving.

Description

[0001] The present description concerns a lockable locking device.

[0002] Storage and transport devices often include a closure configured to cover a compartment. For example, a vehicle might include closures such as a glove box, fuel compartment, storage console, and the like. Such closures generally include a locking mechanism configured to lock and unlock the closure. It may be desirable to lock the enclosure to prevent unauthorized access. It may also be desirable to control the locking and unlocking of the closure remotely, for example, by actuating an electrical switch located some distance from the closure.

[0003] DE 10 2015 105 740 A1 describes a lockable locking device comprising a body defining a cavity and having a longitudinal central axis, and a plunger piston arranged in the cavity. The plunger piston has a first end and a second end and is displaceable along the axis between an open position and a closed position. The device includes an annular rotor arranged along the axis and designed to rotate the plunger piston about the axis. The device also includes an annular locking element that rests against the rotor and is transferable between an unlocked and a locked state.The locking device comprises a first element, which is functionally connected to the locking mechanism and is made of a first shape memory alloy, and a second element, which is functionally connected to the locking mechanism and is made of a second shape memory alloy.

[0004] DE 11 2006 002 705 T5 describes an actuating element comprising a housing, a first lever rotatably attached to the housing, a second lever rotatably attached to the housing, a pivot pin slidably attached to the housing, a pair of spaced-apart selectively retractable wires, each of the pair of selectively retractable wires being connected to the pivot pin and the housing and being ready to move the pivot pin in one of two directions, and wherein a sliding of the pivot pin in a first direction kinematically couples the first and second levers, and wherein a sliding of the pivot pin in a second direction kinematically decouples the first and second levers.

[0005] The task can be considered to be to specify a new and improved system and method for a lockable locking device.

[0006] According to the invention, a lockable locking device comprises a housing that defines a cavity therein and has a central longitudinal axis, and a piston that is arranged within the cavity and has a first end and a second end that is spaced apart from the first end. The piston is displaceable with respect to the housing along the central longitudinal axis between an open position, in which the second end is arranged within the cavity, and a closed position, in which the second end projects out of the cavity.The lockable locking device also includes an annular rotary actuator arranged along the central longitudinal axis and configured to rotate the piston about the central longitudinal axis, and an annular lock adjacent to the annular rotary actuator and displaceable between an unlocked state in which the annular lock is positioned about the central longitudinal axis and between an unlocked state in which the annular lock is positioned about the central longitudinal axis, such that the piston is not displaceable between the open position and the closed position.The lockable locking device further comprises a first element formed from a first shape memory alloy (SMA) which is switchable between a first austenite crystallographic phase and a first martensite crystallographic phase in response to a first activation signal, wherein the first element has a first end fixed relative to the housing and a second end fixed relative to the housing such that the first end of the first element is in a fixed position relative to the second end of the first element.The lockable locking device also includes a second element functionally connected to the ring-shaped locking mechanism and formed from a second shape-memory alloy which is switchable between a second austenite crystallographic phase and a second martensite crystallographic phase in response to a second activation signal, wherein the second element has a first end fixed relative to the housing and a second end fixed relative to the housing such that the first end of the second element is in a fixed position relative to the second end of the second element.The lockable locking device also includes a force transmission mechanism that is functionally connected to the first element, the second element and the annular lock, wherein the force transmission mechanism is configured to transfer the annular lock from the unlocked state to the locked state in response to the first activation signal, and wherein the force transmission mechanism is further configured to transfer the annular lock from the locked state to the unlocked state in response to the second activation signal.Furthermore, the force transmission mechanism comprises a slide configured to move relative to the housing, wherein the slide is forced to move in a first linear direction through the first element in response to the first activation signal, and wherein the slide is forced to move in a second linear direction opposite to the first linear direction in response to the second activation signal. The force transmission mechanism further comprises a lever rotatable about a pivot axis fixed relative to the housing, wherein the lever is forced by the slide to rotate in a first direction of rotation in response to the first activation signal, and wherein the lever is forced by the slide to rotate in a second direction opposite to the first direction of rotation in response to the second activation signal.Furthermore, the lever is functionally coupled to the annular locking mechanism. The lever is also functionally coupled to the annular locking mechanism by a compliant coupling configured to deform elastically when the annular locking mechanism is prevented from moving.

[0007] In one embodiment, the flexible coupling includes an expansion ring that is coupled to the annular locking mechanism.

[0008] In another embodiment, the flexible coupling includes a spring element that extends from the lever to the annular locking mechanism.

[0009] In another embodiment, the lever rotates within a plane that runs parallel to the central longitudinal axis.

[0010] In yet another embodiment, an electrical connection, attached to and movable with the slide, is configured to interact with an electrical circuit to remove the first activation signal or the second activation signal when the slide moves past a predetermined position.

[0011] In another embodiment, the lockable locking device further includes a locking spring configured to hold the annular lock in its last commanded locked or unlocked state in the absence of both the first activation signal and the second activation signal.

[0012] In another embodiment, the lockable locking device further includes an electrical circuit configured to receive a DC voltage and provide the first activation signal when the DC voltage has a first polarity and to provide the second activation signal when the DC voltage has a second polarity opposite to the first. Fig. Figure 1 is an exploded view of sections of a lockable locking device according to an exemplary embodiment; Fig. Figure 2 shows a side view of a housing, a piston, an annular torque and an annular locking mechanism of the lockable locking device. Fig. 1, wherein the piston is arranged in an open and unlocked position according to an exemplary embodiment; Fig. Figure 3 is a side view illustration of the lockable locking device of Fig. 2, wherein the piston is pushed down in the direction of the annular torque and the annular locking mechanism according to an exemplary embodiment; Fig. Figure 4 shows a side view of the lockable locking device of Fig. 1, wherein the piston is arranged in a closed position according to an exemplary embodiment; Fig. Figure 5 is a side view illustration of the lockable locking device of Fig. 4, wherein the piston is arranged in a closed and locked position according to an exemplary embodiment; Fig. Figure 6 is a side view illustration of the lockable locking device of Fig. 5, wherein the ring-shaped locking mechanism is in a locked state according to an exemplary embodiment; Fig. Figure 7 is a partial side view of the lockable locking device of Fig. 6 according to an exemplary embodiment; Fig. Figure 8 is an exploded view of an embodiment of a lockable locking device; Fig. 9A and Fig. Figures 9B are illustrations of a slide valve, which in the embodiment of Fig. 8 is found; Fig. Figure 10 is a representation of the lockable locking device of Fig. 8, in which the ring-shaped locking mechanism is in a locked position; Fig. 11 is a representation of the lockable locking device of Fig. 8, in which the ring-shaped locking mechanism is in an unlocked position, according to one embodiment; and Fig. 12A and Fig. Figures 12B are illustrations of an alternative lever according to an exemplary embodiment.

[0013] Referring to the figures, where similar reference numbers refer to similar elements, it is in Fig. Figure 1 generally shows a lockable locking device 10. The lockable locking device 10 is both sliding, i.e., lockable or latchable, and lockable. That is, the lockable locking device 10 can open, close, lock, and unlock. Therefore, the lockable locking device 10 can be useful for closures and transportation applications. For example, the lockable locking device 10 can be useful for vehicle applications such as fuel filler flaps, glove boxes, storage containers, consoles, and the like. However, the lockable locking device 10 can also be useful for non-vehicle storage applications such as cabinets, locks, safes, and the like.

[0014] With reference to Fig. The lockable locking device 10 comprises a housing 12 that defines a cavity 14 therein and has a central longitudinal axis 16. The housing 12 can generally have a cylindrical shape and protects other components of the lockable locking device 10 from contamination during operation. The housing 12 can have a proximal end 18 and a distal end 20 spaced apart from the proximal end 18 along the central longitudinal axis 16, and can be made of a material such as metal or plastic, depending on the operating conditions of the lockable locking device 10.

[0015] The lockable locking device 10 also includes a piston 22, which is arranged within the cavity 14 and has a first end 24 and a second end 26 spaced apart from the first end 24. The piston 22 can also have a generally cylindrical shape and can slide within the cavity 14 along the central longitudinal axis 16. The first end 24 can be configured to engage a door (not shown) of a closure (not shown), such as a fuel filler door of a vehicle. The first end 24 can define a plurality of elements 28 configured to engage with a corresponding plurality of grooves (not shown) defined by the door. That is, the first end 24 can be wedged into the plurality of grooves. For example, as in Fig. As shown in Figure 1, the plurality of elements 28 form a cross-section and each align with a corresponding plurality of grooves when an operator stops or closes the door. Alternatively, the plurality of elements 28 can form a star, a circle, a square, or another pattern or shape to align with or remain within the plurality of grooves under certain operating conditions. That is, as explained in more detail below, during operation of the lockable locking device 10, the piston 22 can rotate about the central longitudinal axis 16 to alternately align and disalign the plurality of elements 28 with the plurality of grooves defined by the door, thereby engaging the door to open or close it.Conversely, the plurality of elements 28 cannot align with the respective plurality of grooves when the piston 22 rotates about the central longitudinal axis 16, e.g., when the door is open. Furthermore, although not shown, the lockable locking device 10 may also include an elastic element, such as a compression spring, configured to exert a constant force on the piston 22 in an upward direction (indicated by arrow 30 in ). Fig. 5) to be applied along the central longitudinal axis 16.

[0016] With reference to Fig. 2 - 4 the piston 22 is displaceable within the cavity 14. That is, the piston 22 is movable relative to the housing 12 along the central longitudinal axis 16 between an open position 32 ( Fig. 2), in which the second end 26 is arranged inside the cavity 14, and a closed position 34 ( Fig. 4) Displaceable, in which the second end 26 protrudes from the cavity 14. For example, an operator can push the piston 22, e.g., by pushing it against a door (not shown) or a surface (not shown) connected to the first end 24 of the piston 22, to move the piston from the open position 32 to the closed position 34. Therefore, the piston 22 can be in the open position 32 if the door or surface of the closure (not shown) is also open or spaced apart from a complementary component (not shown) to which the door or surface latches and / or locks are attached. Conversely, the piston 22 can be in the closed position 34 if the door or surface of the closure is also closed, e.g., latched and / or locked to the complementary component.This means that when the piston 22 is in the open position 32, an operator can access a storage compartment (not shown) that is covered by the door or surface. However, when the piston 22 is in the closed position 34, the door or surface can seal and cover the storage compartment.

[0017] With further reference to Fig. 1. The piston 22 includes a plurality of legs 36 extending from the second end 26 and spaced apart from each other around the central longitudinal axis 16. The piston 22 can, for example, include four legs 36. The plurality of legs 36 can interact with the housing 12 when the piston 22 is pressed down and between the open position 32 ( Fig. 2) and the closed position 34 ( Fig. 4) is postponed, as explained in more detail below.

[0018] How best in Fig. As shown in Figures 3-6, each of the plurality of legs 36 can generally be triangular. More precisely, each of the plurality of legs 36 can include a first edge 38 that runs substantially parallel to the central longitudinal axis 16, and a second edge 40 that intersects the first edge 38 at a vertex 42 spaced from the second end 26. The first edge 38 and the second edge 40 can form an acute angle 44 ( Fig. 1) Define in between. That is, the second edge 40 can be inclined away from the first edge 38 at less than 90°. Furthermore, each of the plurality of legs 36 can include a third edge 46 that connects the first edge 38 and the second edge 40.

[0019] With reference to Fig. 3 and Fig. 4. The housing 12 can have an inner surface 50 facing the piston 22 and include a plurality of ribs 52 extending along the inner surface 50. Adjacent ribs 52 can define a retaining notch 48 between them. Furthermore, one of the plurality of legs 36 can engage with a retaining notch 48 when the piston 22 is moved from the open position 32 ( Fig. 2) into the closed position 34 ( Fig. 4) translated. How best to translate into Fig. As shown in Figure 5, for example, each of the plurality of legs 36 can adjoin one of the plurality of retaining notches 48 when the piston 22 is in the closed position 34. That is, each leg 36 can contact the respective retaining notch 48, so that the piston 22 can no longer be displaced along the central longitudinal axis 16 in an upward direction 30, i.e., towards the proximal end 18 of the housings 12. Therefore, after an operator initially pushes the piston 22, e.g., B. by pressing against the door (not shown) or the surface connected to the first end 24 to close the door against a complementary component (not shown) in order to enclose and cover a storage compartment (not shown), the piston 22 remains depressed inside the cavity 14, as each of the plurality of legs 36 can bear against one of the plurality of retaining notches 48.

[0020] As with continued reference to Fig. 3 and Fig. As described in section 4, the inner surface 50 can further define a plurality of release channels 54, wherein adjacent plurality of release channels 54 are spaced apart from one another by plurality of ribs 52. Each plurality of legs 36 can be displaceable within a respective plurality of release channels 54 when the piston 22 is arranged in the open position 32 ( Fig. 2) That is, as with reference to Fig. As described in section 2 and further detailed below, when the piston 22 is in the open position 32, not every leg 36 touches the respective retaining notch 48, but is instead possibly displaceable within the respective release channel 54, so that the piston 22 may move along the central longitudinal axis 16 in an upward direction 30, i.e., towards the proximal end 18 of the housing 12, or in a downward direction (indicated by arrow 130 in Fig. 5), i.e., in the direction of the distal end 20 of the housing 12. Therefore, if the plurality of legs 36 is arranged within each of the plurality of release channels 54 after an operator again presses the piston 22, e.g., by pressing again against the door (not shown) or the surface connected to the first end 24, the piston 22 can spring upwards within the cavity 14, since each of the plurality of legs 36 can move within each of the plurality of release channels 54.

[0021] With reference to the Fig. 2 - 6 the piston 22 can also be rotatable about the central longitudinal axis 16 under certain circumstances when the piston 22 is pushed down, i.e. when the piston 22 moves downwards along the central longitudinal axis 16 in the direction 130 ( Fig. 5) is moved. In particular, the piston 22 can be moved between an unlocked position 56 ( Fig. 2 and Fig. 3) be rotatable, in which one of the plurality of legs 36 is positioned about the central longitudinal axis 16, such that the one of the plurality of legs 36 does not abut the retaining notch 48, i.e., is not vertically aligned with the same, when the piston 22 moves towards the distal end 20, and a locked position 58 ( Fig. 4-6), in which one of the plurality of legs 36 is positioned around the central longitudinal axis 16 such that one of the plurality of legs 36 rests against the retaining notch 48, i.e., is aligned with it, while the piston 22 moves towards the proximal end 18. That is, each of the plurality of legs 36 can rest against the retaining notch 48 when the piston 22 is in the locked position 58. In contrast, each of the plurality of legs 36 can be displaceable within each of the plurality of release channels 54 when the piston 22 is in the unlocked position 56. The unlocked position 56 of the piston 22 can correspond to a state in which the door (not shown) or the surface of the closure (not shown) is open and not sealed against a complementary component (not shown), so that a storage compartment (not shown) is accessible.Conversely, the locked position 58 of the piston 22 can correspond to an opposite state in which the door or surface of the closure is closed and connected to the complementary component, so that the storage compartment is covered and inaccessible.

[0022] Therefore, the open position 32 and the closed position 34 of the piston 22 each denote a vertical or longitudinal position of the piston 22 within the cavity 14 along the central longitudinal axis 16, and the unlocked position 56 and the locked position 58 of the piston 22 each denote a rotational position of the piston 22 about the central longitudinal axis 16.

[0023] With reference to Fig. 2. Under certain operating conditions, it should be noted that the piston 22 can be arranged in both the open position 32, i.e., where the second end 26 does not protrude from the cavity 14, and the unlocked position 56, i.e., where each leg 36 is not aligned with any of the plurality of retaining notches 48. This operating state can correspond to a state in which the door (not shown) or the surface of the complementary component (not shown) is open or pivoted.

[0024] However, as in Fig. As shown in Figure 3, after the piston 22 has been initially depressed, it can be arranged in both the closed position 34, i.e., with the second end 26 protruding from the cavity 14, and the unlocked position 56, i.e., with one of the plurality of legs 36 not aligned with a corresponding plurality of retaining notches 48. During such a state, the piston 22 can spring upwards, i.e., in the upward direction 30 ( Fig. 5) within the cavity 14, after the piston 22 has first been pushed down, since the plurality of legs 36 cannot adjoin a corresponding plurality of retaining notches 48.

[0025] In contrast, the piston 22 can, during some operating conditions, such as in Fig. Figures 4-6 show the piston 22 in both the closed position 34, with the second end 26 protruding from the cavity 14 and the locked position 58, and in the locked position 58, i.e., with each leg 36 engaging with one of the plurality of retaining notches 48, so that the piston 22 is held along the central longitudinal axis 16. This operating state can correspond to a state in which the door (not shown) or the surface is closed or locked against the complementary component (not shown) to close or cover the storage compartment (not shown).

[0026] Furthermore, after the piston 22 has been pushed down again for a second time, it can be in both the closed position 34, i.e., with the second end 26 protruding from the cavity 14, and in the unlocked position 56, i.e., with the leg 36 not aligned with or connected to any of the corresponding multiple retaining notches 48, so that each leg 36 can be displaced within any of the multiple retaining channels 54 when the piston 22 moves in an upward direction 30 ( Fig. 5) be moved within the cavity 14. During such a condition, the piston 22 can jump upwards, i.e. in the upward direction 30 within the cavity 14, after the piston 22 has been pushed down again, since the plurality of legs 36 cannot abut any one of the plurality of retaining notches 48 and thus can allow an upward displacement of the piston 22.

[0027] With further reference to Fig. 1 The lockable locking device 10 also includes an annular rotary actuator 60, which is arranged along the central longitudinal axis 16 and is configured to rotate the piston 22 about the central longitudinal axis 16, as is explained in more detail below. In a non-limiting example, the annular rotary actuator 60 may be spaced apart from the housing 12 along the central longitudinal axis 16. The lockable locking device 10 further includes an annular lock 62, which abuts the annular rotary actuator 60 and is configured to actuate the piston 22 under certain operating conditions, such that the piston 22 moves in the upward direction 30 ( Fig. 5) can run within the cavity 14, as will be explained in more detail below. The annular rotary actuator 60 can be arranged between the housing 12 and the annular locking device 62 around the central longitudinal axis 16.

[0028] As mentioned with reference to Fig. As described in 2 - 4, the annular rotary actuator 60 can include a plurality of ramps 64, each configured to guide the apex 42 of a respective plurality of legs 36 to the annular locking mechanism 62 when the piston 22 is between the unlocked position 56 ( Fig. 2 and Fig. 3) and the locked position 58 ( Fig. 4) rotates. That is, the annular rotary actuator 60 can have an inner surface 66 facing the piston 22, and the inner surface 66 can define the plurality of ramps 64. The annular rotary actuator 60 can include a number of ramps 64 corresponding to the number of legs 36 of the piston 22, e.g., four. Each of the plurality of ramps 64 can have an inclined guide surface 68 and be arranged radially around the central longitudinal axis 16 along the inner surface 66 of the annular rotary actuator 60.

[0029] During operation, as in relation to Fig. As described in 2-4, the piston 22 is initially moved downwards by 130° ( Fig. 5) pressed or pushed down towards the distal end 20 of the housing 12 along the central longitudinal axis 16, displacing the piston 22 within the cavity 14 in the direction of the annular rotary actuator 60. As in Fig. As shown in Figure 3, each vertex 42 shifts when each leg 36 touches a corresponding plurality of ramps 64 along the respective plurality of ramps 64 to rotate the piston 22 in a first direction 70 ( Fig. 7) and the piston 22 from the unlocked position 56 ( Fig. 2 and Fig. 3) into the locked position 58 ( Fig. 4) to displace. That is, the annular rotary actuator 60 guides the legs 36 and thereby rotates the piston 22 in the first direction 70, e.g., clockwise, about the central longitudinal axis 16 when the piston 22 is initially depressed. Therefore, the annular rotary actuator 60 converts the longitudinal movement of the piston 22 into a rotary movement and positions the piston 22 in a desired rotary position, i.e., the locked position 58, such that each leg 36 is vertically aligned with each retaining notch 48.

[0030] As such, as can be seen from the comparison of the Fig. 4 and Fig. As described in section 5, after the operator releases the initial downward pressure on the piston 22, e.g., after the operator has determined that the door (not shown) or surface is properly connected or closed to the complementary component (not shown), the piston 22 may easily spring upwards within the cavity 14 and yet be held in the locked position 58, as each leg 36 abuts a corresponding one of the plurality of retaining notches 48.

[0031] With reference to Fig. 4 - 7 is the ring-shaped locking mechanism 62 between an unlocked state 72 ( Fig. 4), in which the ring-shaped locking device 62 is positioned around the central longitudinal axis 16, so that the piston 22 is between the open position 32 ( Fig. 2) and the closed position 34 ( Fig. 4) is movable, and in a locked state 74 ( Fig. 5) movable, in that the annular locking device 62 is positioned about the central longitudinal axis 16 such that the piston 22 is not displaceable between the open position 32 and the closed position 34. The lockable locking device 10 may also include another elastic element (not shown) that can bias the annular locking device 62 into the locked state 74 as the standard or initial state.

[0032] With further reference to Fig. 6 and Fig. 7 The annular locking device 62 can include a plurality of inclined projections 86 extending from the annular base 84 towards the distal end 20, each of the inclined projections 86 being spaced apart from the others about the central longitudinal axis 16. During operation, the apex 42 of each of the plurality of legs 36 can run along each of the plurality of projections 86 while the piston 22 moves from the closed position 34 ( Fig. 6) into the open position 32 ( Fig. 2) transitions when the ring-shaped locking device 62 is forced in a second direction 170, e.g. counterclockwise around the central longitudinal axis 16, by an actuator (not shown).

[0033] With further reference to Fig. 6. After the operator has moved the piston 22 to the closed position 34, the operator may wish to reopen the door (not shown) or the surface of the closure (not shown). To do this, the operator can apply downward pressure to the piston 22, i.e., push the piston 22 again towards the annular rotary actuator 60, while the annular locking mechanism 62 is forced in the second direction 170 by the actuator (not shown).Therefore, when the vertex 42 touches one of the multiple projections 86, the inclined projection 86 can guide the vertex 42 downwards in direction 130, rotate the piston 22 in the first direction 70, and thereby position the piston 22 so that each of the plurality of legs 36 can eventually move within one of the plurality of release channels 54 when the piston 22 moves back upwards in direction 30 along the central longitudinal axis 16 when the operator releases the downward pressure from the piston 22.

[0034] For example, with reference to Fig. As described in Figures 5-7, in a non-restrictive embodiment, when the annular locking device 62 is forced in the second direction 170 by the actuator (not shown), and the piston 22 is simultaneously pressed downwards along the central longitudinal axis 16 to escape from the plurality of retaining notches 48, the plurality of legs 36 may be positioned such that they move within the respective plurality of release channels 54. That is, since the annular locking device 62 is forced in the second direction 170 by the actuator (not shown), the annular locking device 62 can move about the central longitudinal axis 16 and thereby reposition the plurality of inclined projections 86 along the central longitudinal axis 16.Conversely, if the actuator (not shown) pushes the annular locking device 62 in the first direction 70, the annular locking device 62 cannot rotate about the central longitudinal axis 16, and the piston 22 can only retract against the plurality of retaining notches 48 once the downward pressure is removed from the piston 22.

[0035] Consequently, as with regard to Fig. As described in section 4, the apex 42 of each of the plurality of legs 36 can be located, while the piston 22 continues downwards in direction 130 ( Fig. 5) is displaced, coming into contact with one of the plurality of inclined projections 86, which have been repositioned about the central longitudinal axis 16, when the actuator pushes the annular locking element 62 in the second direction 170. The plurality of inclined projections 86 can therefore guide each vertex 42 in the downward direction 130, so that the piston 22 rotates about the central longitudinal axis 16 in the first direction 70. Since each leg 36 is therefore no longer aligned with the respective of the plurality of retaining notches 48 when the downward pressure is released from the piston 22, the piston 22 can spring upwards within the cavity 14 and each of the plurality of legs 36 can move within one of the respective of the plurality of release channels 54. Therefore, the piston 22 can move in the upward direction 30, so that the second end 26 no longer protrudes from the cavity 14 and the piston 22 is arranged in the open position 32 ( Fig. 2) in order to open the door (not shown) or the surface of the closure (not shown) of the complementary component (not shown), e.g. to unlock and unlock.

[0036] Conversely, with renewed reference to Fig. 5 - 7, the piston 22 may not be rotatable about the central longitudinal axis 16 in the second direction 170 if the actuator (not shown) pushes the annular locking device 62 in the first direction 70. Instead, as in Fig. As shown in Figure 5, the annular locking element 62 is positioned away from the leg 36 about the central longitudinal axis 16 when the actuator (not shown) pushes the annular locking element 62 in the first direction 70. Therefore, the closure (not shown) can remain locked so that the door (not shown) or the surface is connected to the complementary component. That is, when the actuator (not shown) pushes the annular locking element 62 in the first direction 70, the annular locking element 62 will not be released to reposition the plurality of inclined projections 86. Such a condition can be useful when it is desired that the closure remain locked and allow an operator to push down the piston 22.This means that the piston 22 can still be displaced away from the distal end 20 along the central longitudinal axis 16 when the piston 22 is in the closed position 34 and the actuator (not shown) pushes the annular locking element 62 in the first direction 70. However, when the operator releases the downward pressure on the piston 22, the piston 22 can only be repositioned along the central longitudinal axis 16 to reposition each leg 36 against one of the plurality of retaining notches 48. Thus, the piston 22 and the door (not shown) or surface can remain in the closed position 34. That is, the door can be both closed and locked, so any attempt to unlock the door will be unsuccessful.Regardless of whether the actuator (not shown) pushes the annular locking element 62 in the first direction 70 or not, the piston 22 can still be displaced downwards in the direction 130 along the central longitudinal axis 16. Regardless of whether the actuator pushes the annular locking element in the first direction 70 or not, an operator can close or lock the door (not shown) or the surface against the complementary component (not shown) of the closure (not shown) at any time.

[0037] Therefore, during operation, and as generally described, when the annular locking device 62 is in the unlocked state 72, the operator can first press against the piston 22, causing the piston 22 to move downwards 130 within the cavity 14 along the central longitudinal axis 16. When the legs 36 of the piston 22 contact the plurality of ramps 64 of the annular rotary actuator 60, the plurality of ramps 64 can guide the legs 36 downwards and in the first direction 70, thereby rotating the piston 22 about the central longitudinal axis 16 until each leg 36 is longitudinally aligned so that it rests against and bears against one of the plurality of retaining notches 48.When the operator removes the applied downward pressure from the piston 22, the piston 22 can rebound in the upward direction 30 along the central longitudinal axis 16 until each leg 36 contacts the respective of the plurality of retaining notches 48, thereby holding the piston 22 in the locked position 58 so that the door (not shown) or the surface on the complementary component (not shown) of the closure can be closed or locked.

[0038] As an option, the operator can then attempt to open or unlock the door (not shown) or the surface of the complementary component (not shown) when the actuator (not shown) pushes the annular lock 62 in the first direction 70. For this option, the operator can again push the piston 22 downwards along the central longitudinal axis 16. However, because the actuator (not shown) pushes the annular lock 62 in the first direction 70, the annular lock 62 may not be in the unlocked state 72, and the plurality of inclined projections 86 may not assist the rotation of the piston 22, so that each leg 36 cannot move toward and within the plurality of release channels 54.Rather, the ring-shaped locking device 62 cannot rotate, and the piston 22 cannot spring back in the upward direction 30 when the applied pressure is removed from the piston 22, so that each leg 36 is again held against one of the plurality of retaining notches 48. Consequently, the piston 22 cannot successfully open or unlock the door (not shown) or the surface.

[0039] It should be noted that even if the operator does actuate the piston 22 once, e.g. possibly in an attempt to open or unlock the door (not shown) or the surface of the complementary component (not shown), the piston 22 will remain in the closed position 34 ( Fig. 5) when the annular locking device 62 is in the locked position 74. That is to say, although the piston 22 is pushed down again in the direction of the annular torque 60 in response to the secondary or additional downward pressure exerted on the piston 22 by the operator, the piston 22 may not continue to rotate about the central longitudinal axis 16 when the annular locking device 62 is in the locked position 74. Rather, the annular rotary actuator 60 is stationary with respect to the housing 12, and the plurality of ramps 64 is only aligned to guide the apex 42 of each leg 36 into a position such that each leg 36 is positioned to bear against the respective plurality of retaining notches 48, with the piston 22 in turn being held against the plurality of retaining notches 48 when the piston 22 is released again in the upward direction 30 ( Fig. 5) Therefore, the operator can press down the piston 22 several times and unlock it successively after the first pressure has been applied against the piston 22, and yet the piston 22 may not rotate into the unlocked position 56 until the ring-shaped locking mechanism 62 is actuated into the unlocked state 72.

[0040] In other words, in order to move the piston 22 from the closed position 34 to the open position 32 and thereby reopen the door (not shown) or the surface connected with the complementary component (not shown), two conditions must be met: 1) downward pressure must be applied to the piston 22, and 2) the annular locking mechanism 62 must be actuated so that the piston 22 can rotate about the central longitudinal axis 16.

[0041] As an alternative option, the operator can then attempt to open or unlock the door (not shown) or the surface of the complementary component (not shown) when the actuator (not shown) pushes the annular lock 62 in the second direction 170. For this option, the operator can again push the piston 22 downwards 130 along the central longitudinal axis 16. As such, the annular lock 62 can move into the unlocked state 72, and the plurality of inclined projections 86 can assist in rotating the piston 22 so that each leg 36 can move a respective inclined projection 86 toward a respective release channel 54 and finally upwards within the respective release channel 54.This means that the annular locking device 62 can rotate in the second direction 170 and the piston 22 can rotate again in the upward direction 30 when the applied pressure is removed from the piston 22, so that each leg 36 is not held against any of the multiple retaining notches 48. Consequently, the piston 22 can successfully open or unlock the door (not shown) or the surface.

[0042] As such, the lockable locking device 10 can be configured as a push-push lock, which is both lockable and latchable. That is, one locking function of the lockable locking device 10 can be controlled by the piston 22, the annular rotary actuator 60, and the housings 12, while a latching function of the lockable locking device 10 can be controlled separately by the annular latch 62 and the actuator. That is, the latching function can be decoupled from the locking function.

[0043] Fig. Figure 8 is an exploded view of an embodiment of a lockable locking device 10. With reference to Fig. Figure 8 includes the lockable locking device 10, which comprises a housing 112 defining a cavity 114 and having a central longitudinal axis 116. The housing 112 can generally have a cylindrical shape and protects other components of the lockable locking device 10 from contamination during operation. The housing 112 can have a proximal end 118 and a distal end 120, which is spaced apart from the proximal end 118 along the central longitudinal axis 116 and can be made of a plastic material according to the operating conditions of the lockable locking device 10.

[0044] The lockable locking device 10 also includes a piston 122, which is arranged within the cavity 114 and has a first end 124 and a second end 126 spaced apart from the first end 124. The piston 122 can also have a generally cylindrical shape and can slide within the cavity 114 along the central longitudinal axis 116. The first end 124 can be configured to engage a door (not shown) of a closure (not shown), such as a fuel filler door of a vehicle. The first end 124 can define a plurality of elements 128 configured to engage with a corresponding plurality of grooves (not shown) defined by the door. That is, the first end 124 can be wedged with the plurality of grooves. For example, as in Fig. As shown in Figure 8, the plurality of elements 128 form a pattern or shape so that, under certain operating conditions, they align with or remain within the plurality of grooves. That is, as explained in more detail below, during operation of the lockable locking device 10, the piston 122 can rotate about the central longitudinal axis 116 to alternately align and disalign the plurality of elements 128 with the plurality of grooves defined by the door, thereby engaging the door to open or close it. Conversely, when the piston 122 is rotating about the central longitudinal axis 116, for example, when the door is open, the plurality of elements 128 cannot align with the respective groove of the plurality of grooves.

[0045] In the Fig. In the embodiment shown in Figure 8, the lockable locking device 10 includes an upper cover 138 and an O-ring 140. The lockable locking device 10 also includes an elastic element in the form of a compression spring 132, which applies a force to the piston 122 in a leftward direction. Fig. 8 is configured along the central longitudinal axis 116. A spring connection 134 and a lower cover 136 allow compression of the compression spring 132 while preventing buckling.

[0046] With further reference to Fig. Figure 8 includes the lockable locking device 10, which also includes an annular rotary actuator 160 arranged along the central longitudinal axis 116. In a non-limiting example, the annular rotary actuator 160 may be spaced apart from the housing 112 along the central longitudinal axis 116. The lockable locking device 10 further includes an annular lock 162, which abuts the annular rotary actuator 160 and is configured to actuate the release of the piston 122 under certain operating conditions, such that the piston 122 moves in the upward direction 30 ( Fig. 5) can run within the cavity 114. The annular rotary actuator 160 can be arranged between the housing 112 and the annular locking device 162 around the central longitudinal axis 116. The embodiment of the in Fig. The lockable locking device shown in Figure 8 also includes a C-spring 164 with a first radially projecting end 214 and a second radially projecting end 216. The C-spring 164 is arranged on an outer surface of the annular locking device 162, so that the C-spring 164 rotates with the annular locking device 162.

[0047] The one in which Fig. The cavity 114 defined in housing 112 shown in Figure 8 has an inner surface analogous to the inner surface 50 of the housing 12 described above, on which a plurality of ribs (not shown) analogous to the ribs 52 and a plurality of release channels (not shown) analogous to the release channels 54 described above are defined. Similarly, the annular rotary actuator 160, which is shown in Figure 8, includes a cavity 114 defined in the housing 112 shown above. Fig. Figure 8 shows an inner surface defining ramps that correspond to the inner surface 66 of the annular rotary actuator 60 described above. The annular lock 162 includes projections analogous to the projections 86 of the annular lock 162 described above. The housing 112, the piston 122, the annular rotary actuator 160, and the annular lock 162 are thus configured to interact to provide the open and closed, locked and unlocked states described above with respect to Fig. 2 - 7 are described to enable this. It is understood that the angles given in the description, which are described in the description of the Fig. 2 - 7 can be modified so that the directions of the piston rotation can be changed according to the locked and unlocked states and / or the directions of the annular locking rotation can be changed according to the locked and unlocked states without deviating from the scope of the present disclosure.

[0048] With further reference to Fig. 8 includes the lockable locking device 10 and an actuator comprising a lever 142, a slide 150, a first FGL element 166, and a second FGL element 168. As described below, the actuator can be operated with these components to rotate the annular locking device 162 in a manner analogous to the actuator discussed in the Fig. 4 - 7 is described as turning the ring-shaped locking device 62.

[0049] With further reference to Fig. 8 The lockable locking device also includes a locking spring 148, a plurality of pins 152, electrical terminals 154, connector pins 156, an electrical circuit 172 and a connector housing 174.

[0050] As in Fig. 10 and Fig. As shown in Figure 11, the lockable locking device 10 includes a first element 166, which is functionally connected to the annular locking mechanism 162 and is formed from a first shape-memory alloy. The first shape-memory alloy is formed between a first martensite crystallographic phase and a first austenite crystallographic phase in response to a first activation signal 176 ( Fig. 10), e.g. a thermal activation signal or heat, switchable to thereby change the ring-shaped locking mechanism 62 from an unlocked state ( Fig. 11) to put into a locked state ( Fig. 10). In the Fig. 10 and Fig. In the embodiment shown in Figure 11, a first end of the first element 166 is anchored to the housing 112 at a first anchoring point 102, and a second end of the first element 166 is anchored to the housing 112 at a second anchoring point 104.

[0051] The lockable locking device 10 also includes a second element 168, which is functionally connected to the ring-shaped locking mechanism 62 and is formed from a second shape-memory alloy. The second shape-memory alloy is sandwiched between a second austenite crystallographic phase and a second martensite crystallographic phase in response to a second activation signal 178 ( Fig. 11), e.g. a thermal activation signal or heat, switchable to thereby change the ring-shaped locking mechanism 62 from the locked state ( Fig. 10) to transfer to the unlocked state ( Fig. 11). In the Fig. 10 and Fig. In the embodiment shown in Figure 11, a first end of the second element 168 is anchored to the housing 112 at a third anchoring point 106, and a second end of the second element 168 is anchored to the housing 112 at a fourth anchoring point 108.

[0052] As in Fig. 10 and Fig. As shown in Figure 11, the first element 166 and the second element 168 are configured in an antagonistic bowstring configuration, whereby a sufficient contraction of the first element 166 exerts a force on the slider 150 to move the slider 150 in a first direction (right in Fig. 10 and Fig. 11) to push, and a sufficient contraction of the second element 168 exerts force on the slide 150 to move the slide 150 in a second direction (to the left in Fig. 10 and Fig. 11) to push in the opposite direction to the first direction, whereby in Fig. 10 the first element 166 and the slide 150 are shown in a state in which the first element 166 is not yet contracted and the slide 150 is shown on the left side, but the lever 142 is already shown schematically in its pivoted position to the right, and wherein in Fig. 11 the second element 168 and the slide 150 are shown in a state in which the second element 168 is not yet contracted and the slide 150 is shown on the right side, but the lever 142 is already shown schematically in its left-hand pivoted position. As in Fig. 9A and Fig. As shown in Figure 9B, the slide 150 includes a top surface 184 from which a first wall 186 and a second wall 188 extend. The slide 150 also includes a bottom surface 190 from which two posts 192 extend, defining a gap 194 between the posts 192. The slide 150 also carries a first electrical connection 196 and a second electrical connection 198 extending from the top surface 184. The function of the electrical connections 196 and 198 will be described later.

[0053] With further reference to Fig. 10 and Fig. Figure 11 further includes the embodiment of the lockable locking device 10, which comprises a lever 142 rotatable about a pivot axis 158. In the illustrated embodiment, the lever 142 includes a first arm 144 and a second arm 146. The second arm 146 is configured to extend into the gap 194 between the posts 192, which extend from the underside 190 of the slide 150. The movement of the slide 150, depending on whether the first element 166 or the second element 168 exerts a greater force on the slide 150, can cause one of the posts 192 to contact the second arm 146, thereby rotating the lever 142 about the pivot axis 158.

[0054] As used herein, the terminology "shape memory alloy" refers to alloys that exhibit a shape memory effect and have the ability to rapidly change their properties with respect to stiffness, spring rate, and / or shape stability. That is, the shape memory alloy may undergo a crystallographic solid-state phase change via molecular or crystalline rearrangement to switch between the martensitic crystallographic phase, i.e., "martensite," and the austenitic crystallographic phase, i.e., "austenite." In other words, the shape memory alloy may undergo a displacement transformation rather than a diffusion transformation to switch between martensite and austenite. A displacement transformation is defined as a structural change that occurs through the coordinated movement of atoms or groups of atoms relative to neighboring atoms or groups of atoms.In general, the martensite phase refers to the comparatively lower temperature phase and is often more deformable than the comparatively higher austenite phase.

[0055] The temperature at which the shape memory alloy transitions from the austenitic crystallographic phase to the martensitic crystallographic phase is known as the martensite start temperature, Ms. The temperature at which the shape memory alloy completes the transition from the austenitic to the martensitic crystallographic phase is known as the martensitic end temperature, Mf. Similarly, as the shape memory alloy is heated, the temperature at which it begins transitioning from the martensitic to the austenitic crystallographic phase will change, known as the austenite start temperature, As. The temperature at which the shape memory alloy completes the transition from the martensitic to the austenitic crystal phase is known as the austenite end temperature, Af.

[0056] The shape memory alloy can have any suitable composition, and the first shape memory alloy can be the same as or different from the second. In particular, the shape memory alloy can include, in combination, an element selected from the group consisting of cobalt, nickel, titanium, indium, manganese, iron, palladium, zinc, copper, silver, gold, cadmium, tin, silicon, platinum, and gallium. For example, suitable shape memory alloys can be nickel-titanium-based alloys, nickel-aluminum-based alloys, nickel-gallium-based alloys, indium-titanium-based alloys, indium-cadmium-based alloys, nickel-cobalt-aluminum-based alloys, nickel-manganese-gallium-based alloys, copper-based alloys (e.g.,The shape memory alloy may include copper-zinc alloys, copper-aluminum alloys, copper-gold alloys, and copper-tin alloys, as well as gold-cadmium-based alloys, silver-cadmium-based alloys, manganese-copper-based alloys, iron-platinum-based alloys, iron-palladium-based alloys, and combinations of one or more of these combinations. The shape memory alloy may be binary, ternary, or any higher order, provided that the shape memory alloy exhibits a shape memory effect, such as a change in shape orientation, damping capacity, and the like. Generally, the first and second shape memory alloys can be selected according to the desired operating temperatures of the lockable locking device 10. In a specific example, the first and / or second shape memory alloy may contain nickel and titanium.

[0057] Therefore, the first element 166 formed from the first shape memory alloy and the second element 168 formed from the second shape memory alloy can be characterized by a cold state, i.e., when the temperature of the shape memory alloy is below the martensite final temperature Mf of the shape memory alloy. Likewise, the first element 166 formed from the first shape memory alloy and the second element 168 formed from the second shape memory alloy can also be characterized by a hot state, i.e., when the temperature of the shape memory alloy is above the austenite final temperature Af of the first and second shape memory alloys.Additionally, although not shown, the lockable locking device 10 can include a plurality of first elements 166 formed from the first shape memory alloy and / or a plurality of second shape memory alloy elements 168 formed from the second shape memory alloy.

[0058] With further reference to Fig. 10. In response to the first activation signal 176, the first element 166 can contract lengthwise to push the slider 150 in a rightward direction. As the slider moves to the right, one of the posts 192 on the underside of the slider 150 contacts the second arm 146 of the lever 142, causing the lever 142 to rotate clockwise about the pivot axis 158. As the lever 142 rotates clockwise, the first arm 144, located in a space between the first radially projecting end 214 and the second radially projecting end 216 of the C-spring 164, contacts the second radially projecting end 216 and pushes the C-spring 164 in a leftward direction. The C-spring 164 is arranged on the outer surface of the annular locking device 162, so that the rotation of the C-spring about the longitudinal axis 116 leads to a rotation of the annular locking device 162 in a first direction about the longitudinal axis 116, e.g.counterclockwise around the central longitudinal axis 116 when viewed from the position of the lower cover 136. In one embodiment, the counterclockwise rotation of the annular locking device 162 corresponds to a locked state of the lockable locking device 10.

[0059] Likewise, with reference to Fig. 11, the second element 168 can contract in length in response to the second activation signal 178 to push the slider 150 in a leftward direction. As the slider moves to the left, the other post 192 on the underside of the slider 150 contacts the second arm 146 of the lever 142, causing the lever 142 to rotate counterclockwise about the pivot axis 158. As the lever 142 rotates counterclockwise, the first arm 144, located in a space between the first radially projecting end 214 and the second radially projecting end 216 of the C-spring 164, contacts the first radially projecting end 214 and pushes the C-spring 164 in a rightward direction.The C-spring 164 is arranged on the outer surface of the annular locking device 162, such that the rotation of the C-spring about the longitudinal axis 116 leads to a rotation of the annular locking device 162 in a second direction about the longitudinal axis 116, e.g., clockwise about the central longitudinal axis 116 when viewed from the position of the lower cover 136. In one embodiment, the clockwise rotation of the annular locking device 162 corresponds to an unlocked state of the lockable locking device 10.

[0060] The second arm 146, extending from the lever 142, is configured to contact the locking spring 148. The locking spring 148 can exert a force on the second arm 146 of the lever 142 to hold the lever 142 in position at or near the point of rotation, i.e., when the annular locking element 162 is either in the unlocked or locked position. That is, the first element 166 and the second element 168 can alternately contract upon exposure to the respective first and second activation signals 176, 178, thereby repositioning the lever 142. However, it should be noted that once the lever 142 is positioned, the locking spring 148 can lock the lever 142 in such a way that no further first and second activation signals 176, 178 are required.This means that the first and second activation signals 176, 178 can be temporary and need not be continuously required to hold the annular locking mechanism 62 in position. As such, the ones in . Fig. 10 and Fig. 11 configurations shown indicate which of the first element 166 and the second element 168 was last activated, even if neither the first activation signal 176 nor the second activation signal 178 is currently being actuated.

[0061] In the foregoing description, the first activation signal 176 and the second activation signal 178 are described as thermal actuation or heat. In an advantageous embodiment, the first activation signal is generated by passing an electric current through the first element 166, resulting in heat generated within the first element 166 due to its inherent electrical resistance. Similarly, the second activation signal is generated by passing an electric current through the second element 168, resulting in heat generated within the second element 168 due to its inherent electrical resistance. With reference to Fig. 8. The electrical current can be supplied through the connecting pins 156, the terminals 154, and the electrical circuit 172. The pins 152 electrically connect the electrical circuit 172 to the first element 166 at the first anchoring point 102 and at the second anchoring point 104. The pins 152 also electrically connect the electrical circuit 172 to the second element 168 at the third anchoring point 106 and at the fourth anchoring point 108. In one embodiment of the disclosure, the circuit within the electrical circuit 172 determines whether electrical current is applied to the first element 166 or to the second element 168 based on the polarity of a DC voltage applied via the connector pins 156.For example, a positive voltage across the connector pins can lead to a current being supplied to the first element 166, while a negative voltage across the connector pins can lead to a current being supplied to the second element 168.

[0062] To prevent permanent stress on the first element 166 and the second element 168, it is desirable to limit the heat applied to the first element 166 and the second element 168. The first electrical connection 196 and the second electrical connection 198 on the slide 150 ( Fig. 9) are configured to interact with elements on the electrical circuit 172 to remove electrical current to the first element 166 or the second element 168 when the position of the slide 150 indicates that the temperature of the respective element exceeds a predetermined threshold. The action of the locking spring 148, as previously described, maintains the position of the lever 142 even when the electrical current is removed from the first element 166 or the second element 168.

[0063] In the event that the annular locking device 162 is temporarily prevented from rotating, for example due to ice accumulation near the annular locking device 162, it is desirable to provide strain relief to prevent permanent damage to components in the lockable locking device 10. In the Fig. In the embodiment shown in Figure 8, the C-spring 164 has sufficient stiffness to rotate the annular locking device 162 under normal operating conditions, but is configured to allow elastic deformation of either the first radially projecting end 214 or the second radially projecting end 216 before plastic deformation of the lever 142 occurs when the annular locking device is held immobile.

[0064] In an alternative embodiment, as in Fig. 12A and Fig. As shown in Figure 12B, the lever 142 can be replaced by a lever 200. The lever 200 includes a first arm 202 and a second arm 204. The second arm 204 is configured to interact with the slide 150 and with the locking spring 148 in a manner analogous to the second arm 146 of the lever 142 described above. The first arm 202 includes a mounting tab 206 for a torsion spring 210. The first arm 202 also includes a locating tab 208. As shown in Figure 12B, the lever 142 can be replaced by a lever 200. Fig. As shown in Figure 12A, the annular lock 162 includes a projection 212. Under normal operating conditions, the torsion spring 210 has sufficient stiffness to contact the projection 212 and force the rotation of the annular lock 162 when the lever 200 rotates. The torsion spring 210 is configured to deform elastically before plastic deformation of the lever 200 occurs when the annular lock is held stationary.

[0065] It may be desirable to detect the position of a door associated with the lockable locking device 10. To achieve this, the lockable locking device 10 may further include a sensor 218, as shown in Fig.Figure 8 shows the sensor 218 as a magnetic field sensor. In one embodiment, the sensor 218 can be a sensor that responds to a magnetic field, including, but not limited to, a reed switch or a Hall-effect sensor. A source of the magnetic field can be provided to generate a first state of the sensor 218 with the door in a first position and a second state of the sensor 218 with the door in a second position. As a non-limiting example of the source of the magnetic field, a permanent magnet (not shown) can be provided on the door (not shown) or on the piston 122. The electrical connection to the sensor 218 can be made by additional connecting pins 156 and / or terminals 154. In a non-limiting exemplary embodiment, the sensor 218 can be mounted on the electrical circuit 172.

[0066] While the best ways of implementing the disclosure have been described in detail, those skilled in the art who are familiar with the technique described herein will recognize various alternative embodiments and designs with which the invention can be implemented within the scope of the patent claims listed below.

[0067] A lockable locking device according to the present disclosure offers several advantages. These include a design to remove electrical excitation from the FGL elements to prevent overheating of the elements, as well as providing strain relief to prevent permanent damage in the event of a temporary disturbance with the movement of the annular locking mechanism.

Claims

[1] Lockable locking device (10), comprising: a housing (12) defining a cavity (14) therein and having a central longitudinal axis (16); a piston (22) disposed within the cavity (14) and having a first end (24) and a second end (26) spaced from the first end (24), the piston (22) being slidable with respect to the housing (12) along the central longitudinal axis (16) between: an open position (32) in which the second end (26) is disposed within the cavity (14); and a closed position (34) in which the second end (26) protrudes from the cavity (14); an annular rotary actuator (60) arranged along the central longitudinal axis (16) and configured to rotate the piston (22) about the central longitudinal axis (16); an annular lock (62) abutting the annular rotary actuator (60) and movable between: an unlocked state (72) in which the annular lock (62) is positioned about the central longitudinal axis (16) such that the piston (22) is movable between the open position (32) and the closed position (34); and a locked state (74) in which the annular lock (62) is positioned about the central longitudinal axis (16) such that the piston (22) is not movable between the open position (32) and the closed position (34); a first element (166) formed from a first shape memory alloy switchable between a first austenite crystallographic phase and a first martensite crystallographic phase in response to a first activation signal (176), the first element (166) having a first end fixed relative to the housing (12) and a second end fixed relative to the housing (12) such that the first end of the first element (166) is in a fixed position relative to the second end of the first element (166); a second member (168) operatively connected to the annular lock (62) and formed from a second shape memory alloy switchable between a second austenite crystallographic phase and a second martensite crystallographic phase in response to a second activation signal (178), the second member (168) having a first end fixed relative to the housing (12) and a second end fixed relative to the housing (12) such that the first end of the second member (168) is in a fixed position relative to the second end of the second member (168); a force transmission mechanism operatively connected to the first member (166), the second member (168), and the annular lock (62), the force transmission mechanism being configured to transition the annular lock (62) from the unlocked state (72) to the locked state (74) in response to the first activation signal (176), the force transmission mechanism being further configured to transition the annular lock (62) from the locked state (74) to the unlocked state (72) in response to the second activation signal (178); wherein the force transmission mechanism comprises a slider (150) configured to move relative to the housing (12), wherein the slider (150) is urged by the first member (166) to move in a first linear direction in response to the first activation signal (176), and wherein the slider (150) is urged by the second member (168) to move in a second linear direction opposite the first linear direction in response to the second activation signal (178); wherein the power transmission mechanism further comprises a lever (142) rotatable about a pivot axis (158) fixed relative to the housing (12), wherein the lever (142) is urged by the slider (150) to rotate in a first rotational direction in response to the first activation signal (176), and wherein the lever (142) is urged by the slider (150) to rotate in a second rotational direction opposite the first rotational direction in response to the second activation signal (178); wherein the lever (142) is operatively coupled to the annular lock (62); and wherein the lever (142) is operatively coupled to the annular lock (62) by a resilient coupling configured to elastically deform when the annular lock (62) is prevented from moving. [2] The lockable locking device (10) of claim 1, wherein the resilient coupling comprises an expansion ring coupled to the annular lock (62). [3] The lockable locking device (10) of claim 1, wherein the resilient coupling comprises a spring element extending from the lever (142) to the annular lock (62). [4] Lockable locking device (10) according to claim 1, wherein the lever (142) is configured to rotate within a plane parallel to the central longitudinal axis (16). [5] The lockable locking device (10) of claim 1, wherein an electrical terminal (196, 198) fixed and movable to the slider (150) is configured to cooperate with an electrical circuit (172) to remove the first activation signal (176) or the second activation signal (178) when the slider (150) moves past a predetermined position. [6] The lockable locking device (10) of claim 1, further comprising a detent spring (148) configured to maintain the annular lock (62) in its last commanded locked state or unlocked state in the absence of both the first activation signal (176) and the second activation signal (178).

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