Electromagnetically actuated locking latch with retention mechanism

Abstract

Actuated pawl assembly (10, 100, 100', 200) with a motion control mechanism (50, 58) for use with a motor vehicle system, comprising: a rotating hub with multiple teeth (16, 106) separated by tooth gaps (18, 108) between each adjacent pair of the multiple teeth (16, 106); a pawl (24) movable between a disengaged position in which the pawl is not in contact with the rotating hub, an engaged position in which the pawl (24) is in contact with the rotating hub, and an intermediate position between the disengaged position and the engaged position;a locking cam (36) which is in contact with the pawl (24), wherein the locking cam (36) moves between a disengaged position, so that the pawl (24) is in the disengaged position with respect to the rotating hub, an engaged position, so that the pawl (24) is in contact with the rotating hub, and an intermediate position between the disengaged position and the engaged position;and an actuator connected to the locking cam (36), wherein the actuator moves between a retracted position and an extended position, wherein each tooth gap (18, 108) has an anterior tooth profile (20) of one of the multiple teeth of the adjacent pair of multiple teeth and a posterior tooth profile (22) of a second of the multiple teeth of the adjacent pair of multiple teeth, further comprising a latch head (30) of the latch (24), characterized in that the latch head (30) has an anterior latch profile (32) and a posterior latch profile (34), wherein the posterior latch profile (34) has a shape that matches the posterior tooth profile (22) of each tooth gap (18, 108), and the anterior latch profile (32) of the latch head (30) matches the anterior tooth profile (20) of each tooth gap (18, 108).

Description

AREA OF INVENTION

[0001] The present invention relates to an electromagnetically actuated pawl arrangement with a motion control mechanism for use in a motor vehicle drive system. BACKGROUND OF THE INVENTION

[0002] Motor vehicles use a drive and motor system that typically involves a rotating gear or hub to convert rotary motion into linear motion. Such hubs are often found in transmission components or sometimes on the motor shaft itself. Many electric vehicles now also use hubs as part of their motor and transmission components. There is a need for selective locking and unlocking of the hubs under varying conditions. The hubs have teeth separated by a tooth gap. One method of locking and unlocking the hub to prevent rotation is achieved by selectively moving a wedge into the tooth gap to lock the hub against rotation in all directions. Such locking mechanisms are bulky, as they may require cumbersome actuators or wedge mechanisms.One object of the invention is to provide a smaller arrangement that uses a linear actuator, such as an electromagnetic actuator. However, electromagnetic actuators function best when they can move through their entire stroke without being stopped, which can damage or wear the actuator. Therefore, another object of the invention is to provide a motion retention feature between the shaft and the actuator that maintains a force on the locking components when they cannot be fully engaged, but also allows movement of the linear actuator through its full stroke. BRIEF SUMMARY OF THE INVENTION

[0003] The present invention relates to a pawl assembly with a motion-control mechanism for use with various motor vehicle devices, comprising a rotating hub with multiple teeth. The rotating hub has a tooth gap between each adjacent pair of teeth. Furthermore, a pawl is provided that is movable between a disengaged position, in which the pawl is not engaged with the rotating hub, an engaged position, in which the pawl is engaged with the hub, and an intermediate position between the disengaged and engaged positions. A locking cam is in contact with the pawl and moves between a disengaged position, an engaged position, and an intermediate position relative to the pawl. An actuator is also provided that can be engaged with the locking cam.The actuator moves between a retracted position and an extended position, causing the locking cam to move the pawl between the intermediate position, the disengaged position, and the retracted position. List of characters

[0004] The present invention will be better understood with reference to the detailed description and the accompanying drawings, wherein: Fig. 1 is a schematic side view of the actuated pawl assembly, showing the motion retention mechanism in the disengaged position; Fig. 2 is a schematic side view of the actuated pawl assembly, showing the motion retention mechanism in the engaged position; Fig. 3 is an enlarged schematic perspective under-view of the actuated pawl assembly, showing the motion control mechanism in the engaged position; Fig. 4 is an enlarged schematic perspective under-view of the actuated pawl assembly, showing the motion retention mechanism in the intermediate position; Fig. Figure 5 shows an enlarged cross-sectional side view of an actuated pawl arrangement with a U-shaped pawl in the engaged position according to a second embodiment of the invention; Fig. Figure 6 shows an enlarged cross-sectional side view of an actuated pawl arrangement with a U-shaped pawl in the engaged position according to the second embodiment of the invention; Fig. Figure 7 shows an enlarged cross-sectional side view of an actuated pawl assembly with a U-shaped pawl having a motion retention mechanism, according to another aspect of the second embodiment of the invention; Fig. Figure 8 shows an enlarged perspective end view of a housing containing the actuated pawl assembly with a U-shaped pawl according to a second embodiment of the invention; Fig. 9 is a schematic side cross-sectional view of another embodiment of the motion control mechanism; Fig. 10 represents an enlarged cross-sectional side view of a yielding latch in the stowed position according to a third embodiment of the invention; Fig. Figure 11 shows an enlarged cross-sectional side view of a compliant latch in the ratchet position according to the third embodiment of the invention; Fig. Figure 12 shows an enlarged cross-sectional side view of a yielding latch in the inset position according to the third embodiment of the invention; Fig. Figure 13 shows a side view of the two-part latch according to the third embodiment of the invention. DETAILED DESCRIPTION OF PREFERRED EXECUTION FORMS

[0005] The following description of preferred embodiments is purely exemplary and is not intended to limit the invention, its application or uses in any way.

[0006] Now on Fig. Referring to Figures 1-4, an actuated pawl assembly 10 with a motion-holding mechanism 12 is shown. The actuated pawl assembly 10 is intended for general use with an automotive system and can be implemented in several different areas, such as transmissions, parking brakes, electric motors, electric vehicle powertrains, seat belts, vehicle closures such as trunks, hoods, doors, and in window and convertible actuators, but these are not limited to such applications. The actuated pawl assembly 10 has a hub 14, which is a bidirectional rotating hub capable of rotating either clockwise or counterclockwise; however, in some applications, the hub 14 is configured to rotate in only one direction.

[0007] The hub 14 has several teeth 16 separated by a tooth gap 18, which is shown in the figures between an adjacent pair A, B of the several teeth 16. Although only a single tooth gap is indicated, it is understood that each adjacent tooth on the hub 14 is separated by a tooth gap. The tooth gap 18 (as well as all tooth gaps on the hub 14) has an anterior tooth profile 20 and a posterior tooth profile 22.

[0008] Near the hub 14 is a pawl 24, which is connected to a support 26 and can rotate around it. The pawl 24 is located between a Fig. 1 shown in the disengaged position, in which the pawl 24 is not engaged with the hub 14, one in Fig. 2 shown in the recessed position, in which the latch 24 engages with the hub and is partially positioned in a tooth gap 18, and one in Fig. The intermediate position shown in Figure 3, which lies between the disengaged and engaged positions, and in which the pawl 24 is in contact with the hub 14 but is not in any tooth gap, is movable or rotatable. The pawl 24 is preloaded to rotate by a spring 28 connected between the body of the pawl 24 and a base (e.g., housing, support, or any other stationary surface) in order to preload the pawl 24 in the disengaged position.

[0009] At the in Fig. In the embodiment shown in Figures 1-4, the hub 14 rotates bidirectionally, so that when the pawl 24 is in the engaged position, it is desirable for a pawl head 30 of the pawl 24 to fit tightly into a tooth gap 19, thus preventing the pawl 24 from rotating the hub 14. The pawl head 30 has a front pawl profile 32 and a rear pawl profile 34, the rear pawl profile 34 having a shape that matches the rear tooth profile 22 of each tooth gap 18. The front pawl profile 32 of the pawl head 30 matches the front tooth profile 20 of each tooth gap 18, so that the pawl head 30 fits tightly into the tooth gap 18 to prevent any play in the hub 14.To prevent any movement of the hub 14, whether due to play or other factors, each anterior tooth profile 20 of all multiple teeth 16 has a first depression angle or inclination, and each posterior tooth profile 22 of all multiple teeth 16 has a second depression angle or inclination, such that the first depression angle differs from the second depression angle. The reason for this difference in the first and second depression angles is that the engagement radius of the hub 14, and where the pawl head 30 contacts the hub 14, is different. This necessitates that the anterior tooth profile 20 and the posterior tooth profile 22 be different and have different depression angles to ensure that the pawl head 30 sits properly in the tooth gap, which moves radially.In other words, due to the way the hub 14 rotates and the way the pawl head 30 makes contact in any given tooth gap 18, different angles are required at the front tooth profile 20 and rear tooth profile 22. Depending on the design of the actuated pawl assembly 10, the first depth angle of the front tooth profile 20 and the second depth angle of the rear tooth profile 22 depend on several factors, including one or more factors selected from the group consisting of the diameter of the bidirectionally rotating hub 14, the number of teeth, the depth of the tooth gap, and the position and angle of engagement of the pawl head.

[0010] The actuated pawl assembly 10 also has a locking cam 36 with a surface 38 that is in contact with the pawl 24. The locking cam 36 is rotatably connected to a support 40 and moves between a Fig. 1 shown deployed position, one in Fig. 2-3 shown indented position and one in Fig. The intermediate position shown in Figure 4 is located between the disengaged and engaged positions. The locking cam 36 serves as an intermediary for transmitting force between an actuator 42 and the pawl 24. A spring 44 is connected around the support 40 and is connected between the locking cam 36 and a base (e.g., housing, support, or any other stationary surface), and biases the locking cam into the disengaged position when the actuator 42 is not acting on the locking cam 36.

[0011] The actuator 42 is connected to the locking cam 36 and moves between a in Fig. 1 shown in the retracted position and one in Fig. 2-4 shown in the extended position. In a preferred embodiment of the invention, the actuator 42 is a linear actuator and is shown in the drawings as an electromagnetic actuator. Although an electromagnetic actuator is shown, the scope of protection of the present invention includes the use of other linear actuators, such as one selected from the group comprising an electromagnetic actuator, a spindle actuator, a cam actuator, a hydraulic piston actuator, a pneumatic cylinder actuator, and a linear servo actuator. The actuator 42 has a shaft 46 that moves linearly between the retracted position and the extended position. The shaft 46 is aligned with an opening 48 on the locking cam 36, the shaft 46 moving through the opening 48 into the retracted position when the locking cam is in the intermediate position, as shown in Fig. 4 shown, is located, and is not in the indented position, as shown in Fig. Figure 3 shows how the actuator 42 can move, which occurs when the pawl head 30 cannot move into the tooth gap 18 and is in contact with one of the several teeth 16 of the hub 14. This protects the actuator 42 from damage or wear by allowing the actuator 42 to move through a full range of motion, even if a full movement of the pawl 24 is blocked.

[0012] The actuated pawl assembly 10 also includes a motion-holding mechanism 50, which is connected between the actuator 42 and the locking cam 36 and allows the actuator 42 to move into the extended position if the locking cam 36 cannot move past the intermediate position. The motion-holding mechanism maintains a force on the locking cam 36 until the hub 14 moves into a position in which the pawl head 30 moves into the engaged position and the locking cam 36 moves into the engaged position due to the force applied by the motion-holding mechanism 50.

[0013] How best to Fig. As shown in Figures 3-4, the motion-holding mechanism 50 has a compression spring 52 arranged around the shaft 46 and held between an upper washer 54, which is fixed to the shaft 46, and a lower washer 56, which can slide on the shaft 46. This allows the shaft 46 to slide through the lower washer 54 and through the opening 48 in the locking cam 36 if the locking cam cannot move past the intermediate position. When this occurs, the compression spring 52 between the upper washer 54 and the lower washer 56, which rests against the locking cam 36, is compressed to provide the necessary force.The lower washer 56 has a flat surface in the illustration, which contacts the compression spring 52. However, it is within the scope of the present invention to provide a flat surface or a conical / spherical surface that contacts the locking cam 36. The advantage of using a conical / spherical shape is that, in addition to the conical surface providing more uniform movement compared to a flat washer, since it rolls on the surface between the conical / spherical surface and the locking cam 36, there would also be a larger contact area between the conical / spherical surface and the locking cam 36.The use of the motion control mechanism 50 allows the use of a more compact and efficient actuator, such as an electromagnetic actuator, while the electromagnetic actuator is protected by the fact that it can move through its full stroke between the extended and retracted positions without unwanted impact of the shaft 46 against the locking cam 36, which could damage the actuator 42 or reduce its service life.

[0014] Now on Fig. 9 With reference to this, there is an alternative embodiment which has a motion control mechanism 58 which represents an alternative arrangement compared to the one described in Fig. Figures 3-4 represent the motion control mechanism 50. In this embodiment of the invention, an electromagnetic actuator 60 is provided, which has a linearly movable armature 62 with an upper spring seat 64 and a shaft 66 extending from the upper spring seat 64 away from the armature 62. The armature 62 and the shaft 66 move linearly between a retracted position and an extended position.

[0015] The motion control mechanism 58 has a piston 68 which contacts the locking cam 36 and, as a result of the movement of the locking cam 36, which moves between the disengaged position, the engaged position and the intermediate position, as shown above. Fig. As described in sections 1-4, the piston 68 moves between a retracted position, a disengaged position, and an intermediate position between the retracted and disengaged positions. The piston 68 has a blind hole 70 with a depth sufficient to accommodate part of the shaft 66 of the electromagnetic actuator 60 when the electromagnetic actuator 60 moves between the extended and retracted positions. A compression spring 72 is arranged around the shaft 66 and is held between the upper spring seat 64 on the armature 62 and a lower spring seat 74 on the piston 68.If the piston 68 cannot move past the intermediate position, the shaft 66 slides further into the blind hole 70 of the piston 68, allowing the shaft 66 to move into the extended position, and the compression spring 72 is compressed as the upper spring seat 64 moves towards the lower spring seat 74, causing the compression spring 72 to provide force to the piston 68. The force is released when the locking cam 36, as a result of rotation of the hub 14, can move into the engaged position to allow the pawl head 30 to move into the tooth gap 18, as described above with reference to [reference missing]. Fig. 1-4 described.

[0016] Now on Fig. Referring to Figures 5-8, an alternative embodiment of the invention is shown as an actuated pawl assembly 100 with a U-shaped pawl 102. The actuated pawl assembly 100 is used in an environment in the position of a started engine and engages a conventional starter gear. However, it is within the scope of the invention that the pawl assembly 100 is used in other applications, including a bidirectionally rotating hub, as described above with reference to Figures 5-8. Fig. 1-4 described. The actuated pawl assembly has a hub 104, which is a rotating hub with several teeth 106 and several tooth gaps 108. In this embodiment of the invention, the profile of each of the several teeth 106 is the same on both flanks; thus, there is no difference between the front tooth profile and the rear tooth profile, as described above with reference to Fig. 1-4 described. The multiple teeth 106 are each separated by one of the multiple tooth gaps 108, so that between each adjacent pair A', B' of the multiple teeth 106.

[0017] The actuated pawl assembly 100 has a housing 110 with two opposing pawl mounting points 112, 112'. A U-shaped pawl 102, with a first engagement arm 114 and a second engagement arm 116, is both connected to a body section 118, which includes a pivot pin 120, 120' for pivotally connecting the U-shaped pawl 102 to one of the two opposing pawl mounting points 112, 112' in the housing 110. The pivot pin 120, 120' is a support that is placed at or positioned on each of the mounting points 112, 112'.The U-shaped latch 102 is rotatable between a disengaged position in which the second engagement arm 116 is not in contact with the rotating hub 104, a retracted position in which the second engagement arm 116 is partially positioned in one of the multiple tooth gaps 108, and an intermediate position in which the second engagement arm 116 is in contact with one or more of the multiple teeth 106 and is not positioned in one of the multiple tooth gaps 108.

[0018] An actuator 122 is connected to the housing 110 and has a shaft 124 that moves between an extended position and a retracted position. When moving into the extended position, the shaft 124 contacts the first engagement arm 114 of the U-shaped pawl 102 and rotates the U-shaped pawl 102 from the disengaged position to the engaged position. When the shaft 124 moves into the retracted position, it moves away from the first engagement arm 114 and does not contact it. A preloading element 126 (in Fig. 8 shown), such as a spring, is connected between the U-shaped pawl 102 and a base (e.g. housing 110, pivot pin 120 or other stationary structure) to preload the U-shaped pawl 102 to pivot into the disengaged position.

[0019] Now on Fig. 6 With reference to this, the reversible aspect of the U-shaped latch 102 is explained. As shown, the U-shaped latch 102 has been moved from the latch mounting point 112 to the latch mounting point 112'. This allows the U-shaped latch 102 to be in a Fig. 5 shown, rotating hub 104' in the opposite direction to lock. In Fig. 5 the hub 104 rotates clockwise, while the hub 104' in Fig. 6 rotates counterclockwise. Furthermore, the orientation is changed by moving the U-shaped latch 102, so that in Fig. 6 the first engagement arm 114 is in contact with the hub 104, while the second engagement arm 116 is in contact with the shaft 124 of the actuator 122.

[0020] Fig. Figure 8 shows an end view of the housing 110, with the U-shaped latch 102 positioned within the housing 110. The housing 110 has two notches 128, 128' which partially accommodate the spring 126 for support, depending on which latch mounting point 112, 112' is used. Furthermore, the first engagement arm 114 has a width 130 that is wider than the width 132 of the second engagement arm 116. This is because the smaller width of 130 is possible since, due to the position of the shaft 124, it is not necessary for the widths to be the same. This ensures additional weight and cost savings provided by the current embodiment.

[0021] On Fig. 7. Referring to another embodiment, an actuated pawl assembly 100' has a motion-holding mechanism 134. The motion-holding mechanism 134 has a spring 140 positioned around a shaft 124' of the actuator 122'. The spring 140 is held on the shaft 124' by a spring seat 136 and a washer 138, which slides on the shaft 124. The washer 138 is in contact with a U-shaped pawl 102' when the actuator 122' moves into the extended position. If the U-shaped pawl 102' cannot move into the retracted position, the shaft 124 slides through an opening 139 in the U-shaped pawl 102' and moves into the extended position, thereby allowing the motion-holding mechanism 134 to maintain a force on the U-shaped pawl 102', similar to the one in Fig. 1-4 described movement control mechanism 12.

[0022] Fig. Figures 10-12 show an enlarged cross-sectional side view of an actuated pawl assembly 200 according to a third embodiment of the invention. This embodiment uses the same housing 110, pivot pin 120', pawl attachment points 112, 112', actuator 122' and shaft 124' similar to those shown above. Fig. 5-8 shown, therefore the same reference numbers are taken from the Fig. 5-8 on the Fig. 10-12 have been transferred and are used there. The actuated locking pawl assembly 200 has a two-part pawl 202, which is divided between a in Fig. 10 shown deployed positions, one in Fig. 12 shown indented positions and one in Fig. The ratchet position shown in Figure 11 is moved, all of which relate to a rotatable gear 224. It is conceivable that the gear 224 is part of a motor braking system in the present invention; however, it is possible that the actuated pawl arrangement 200 is used in other systems described above.

[0023] The two-part latch 202 has a lower jaw 204 and an upper jaw 206, both of which are pivotally attached to the pivot pin 120 connected to one of the latch mounting points 112, 112' on the housing 110. The upper jaw 206 has an upper seat 210, and the lower jaw 204 has a lower seat 212. A resilient spring 214 is positioned between the upper seat 210 and the lower seat 212 and biases the lower jaw 204 and the upper jaw 206 away from each other. As is best done in Fig. As shown in Figure 13, the upper jaw 206 has an upper stop 221 and a lower stop 222, between which the lower jaw 204 pivots. The upper stop 221 and the lower stop 222 prevent the lower jaw 204 and the upper jaw 206 from opening beyond the uncompressed length of the resilient spring 214 or from compressing the resilient spring 214 excessively to the point of becoming stuck or damaged. This allows the overall height of the two-part latch 202 in its most fully extended or retracted state to be known, while furthermore allowing the arrangement of the two-part latch 202 to be handled on an assembly line where it is less likely to fall out during assembly when no stops are present.

[0024] The actuated pawl assembly 200 further comprises the actuator 122', which in this embodiment is an electromagnet connected to the housing 110, with a shaft 124' extending into the housing 110 and in contact with the lower jaw 204 of the two-part pawl 202. The lower jaw 204 of the two-part pawl 202 has a radius 216 that contacts a shaft radius 218 on the shaft 124 to provide smooth movement between the actuator 122' and the lower jaw 204. A return spring 220 is positioned around the pivot pin 120' and is connected between the lower jaw 204 and the housing 110. The return spring 220 moves the lower jaw 204 into contact with the lower stop 222 formed on the upper jaw 206 in order to move the entire two-part pawl 202 into the stowed position when the shaft 124' moves into the retracted position.

[0025] The operation of the actuated locking pawl arrangement 200 is described in Fig. Shown 10-12. In Fig. 10 the shaft 124' is moved into a retracted position, and the two-part pawl 202 is pivoted into a nested position by the preload of the return spring 220, as in Fig. Figure 10 shows that the shaft radius 218 can either be in contact with the radius 216 of the shaft 124' or can be drawn in to the point where there is no contact.

[0026] To release the actuated pawl assembly 200, the actuator 122 is actuated, and the shaft radius 218 of the shaft 124 moves upwards and touches (if it is not already in contact) the radius 216 of the lower jaw 204, exerting a force on it. This presses against the resilient spring 214, thereby transmitting an upward force to the upper jaw 206, which causes the entire two-part pawl 202, together with the upper jaw 206, to move upwards towards the gear 224.When the gear 224 rotates at a high speed, when the upper jaw 206 of the two-part pawl 202 comes into contact with the gear 244, the upper jaw 206 is deflected downwards again towards the lower jaw 204, and the resilient spring 214 pushes the upper jaw 206 upwards again, thus creating a ratchet mode as the upper jaw 206 is pushed back and forth by the movement of the moving gear 224 and the force of the resilient spring 214. The ratchet mode is in . Fig. Figure 11 shows that the ratchet mode occurs when the actuator force is greater than the ratchet force and the helical spring force is less than the actuator force. If the gear 224 were to slow down sufficiently so that the upper jaw 206 engages a tooth on the gear 224 (as shown in Figure 11), the ratchet mode would occur. Fig. (as shown in Figure 12) engages the gear 224, and the torque load is transferred through the upper jaw 206 to the rear of the pocket of the housing 110, where the two-part pawl 202 is located. When the actuator 122 is deactivated and there is no torque load on the gear, the two-part pawl 202 retracts into the housing 110 due to the force provided by the return spring 220, which reacts between the housing 110 and the lower jaw 204. The ratchet mode continues until either the shaft 124 moves into the disengaged position, as shown in Figure 12. Fig. 10 shown, moved back or until the gear 224 slows down sufficiently so that the upper jaw 206 engages the teeth and locks the gear 225 against movement, as shown in Fig. 12 shown.

[0027] The description of the invention is merely exemplary, and therefore variations that do not deviate from the essence of the invention are to fall within the scope of protection of the invention. Such variations are not considered a departure from the concept and scope of protection of the invention.

Claims

[1] An actuated pawl assembly having a motion retention mechanism for use with a motor vehicle system, comprising: a rotating hub having a plurality of teeth separated by tooth spaces between each adjacent pair of the plurality of teeth; a pawl movable between a disengaged position in which the pawl is not in contact with the rotating hub, an engaged position in which the pawl is in contact with the rotating hub, and an intermediate position between the disengaged position and the engaged position; a locking cam in contact with the pawl, the locking cam being movable between a disengaged position such that the pawl is in the disengaged position with respect to the rotating hub, an engaged position such that the pawl is in contact with the rotating hub, and an intermediate position between the disengaged position and the engaged position; and an actuator connected to the locking cam, the actuator moving between a retracted position and an extended position. [2] The actuated pawl assembly of claim 1, wherein each tooth gap includes a leading tooth profile of one of the plurality of teeth of the adjacent pair of the plurality of teeth and a trailing tooth profile of a second of the plurality of teeth of the adjacent pair of the plurality of teeth. [3] The actuated pawl assembly of claim 2, further comprising a pawl head of the pawl, the pawl head having a front pawl profile and a rear pawl profile, the rear pawl profile having a shape that mates with the rear tooth profile of each tooth space, and the front pawl profile of the pawl head mates with the front tooth profile of each tooth space. [4] The actuated pawl assembly of claim 2, wherein each front tooth profile of all of the plurality of teeth has a first depth angle and each rear tooth profile of all of the plurality of teeth has a second depth angle, the first depth angle being different from the second depth angle. [5] The actuated pawl assembly of claim 4, wherein the first depth angle and the second depth angle are determined by one or more factors selected from the group consisting of a diameter of the rotating hub, the number of the plurality of teeth, a depth of the tooth gap, and the position and angle of engagement of the pawl head. [6] The actuated ratchet assembly of claim 1, further comprising a movement retention mechanism connected between the actuator and the locking cam and allowing the actuator to move to the extended position when the locking cam cannot move past the intermediate position, the movement retention mechanism maintaining a force on the locking cam until the rotating hub moves to a position where the pawl head moves to the engaged position and the locking cam moves to the engaged position due to the force applied by the movement retention mechanism. [7] An actuated ratchet assembly according to claim 6, wherein the actuator is a linear actuator having a shaft that moves linearly between the retracted position and the extended position, and the movement retention mechanism comprises a compression spring disposed around the shaft and captured between an upper washer fixed to the shaft and a lower washer slidable on the shaft, such that when the locking cam cannot move past the intermediate position of the shaft, the shaft of the linear actuator slides through the lower washer and through an opening in the locking cam to allow the shaft of the actuator to move to the extended position, and the compression spring is compressed as the shaft slides and the upper washer moves toward the lower washer abutting against the locking cam, the compression spring acting on the lower washer,to provide the force to the locking cam. [8] The actuated pawl assembly of claim 7, wherein the linear actuator is one selected from the group consisting of an electromagnetic actuator, a spindle actuator, a cam actuator, a hydraulic piston actuator, an air cylinder actuator, and a linear servo actuator. [9] The actuated pawl assembly of claim 1, wherein the actuator is a linear actuator selected from the group consisting of an electromagnetic actuator, a spindle actuator, a cam actuator, a hydraulic piston actuator, an air cylinder actuator, and a linear servo actuator. [10] An actuated pawl assembly having a U-shaped pawl, comprising: a rotating hub with several teeth and several tooth gaps, wherein the plurality of teeth are each separated by one of the plurality of tooth gaps; a housing, a U-shaped pawl having a first engagement arm and a second engagement arm, both connected to a body portion including a pivot for pivotally connecting the U-shaped pawl to the housing, the U-shaped pawl being movable between a disengaged position in which the second engagement arm is not in contact with the rotating hub, an engaged position in which the second engagement arm is partially positioned in a tooth gap of the plurality of tooth gaps, and an intermediate position in which the second engagement arm is in contact with one or more of the plurality of teeth and is not positioned in one of the plurality of tooth gaps; and an actuator connected to the housing and having a shaft that moves between a retracted position and an extended position, wherein the shaft contacts the second engagement arm of the U-shaped pawl upon movement to the extended position and the U-shaped pawl rotates from the disengaged position to the engaged position, and the shaft moves away from the second engagement arm upon movement of the shaft to the disengaged position. [11] The actuated pawl assembly of claim 10, further comprising a biasing member connected between the housing and the body of the U-shaped pawl for moving the U-shaped pawl to the disengaged position when the shaft of the actuator moves to the retracted position. [12] The actuated pawl assembly of claim 10, further comprising a movement retention mechanism connected between the shaft of the actuator and the U-shaped pawl and allowing the actuator to move to the extended position when the U-shaped pawl cannot move past the intermediate position, the movement retention mechanism maintaining a force on the U-shaped pawl until the rotating hub moves to a position where the U-shaped pawl moves to the engaged position and the U-shaped pawl moves to the engaged position due to the force applied by the movement retention mechanism. [13] An actuated pawl assembly according to claim 12, wherein the actuator is a linear actuator having a shaft that moves linearly between the retracted position and the extended position, and the movement retention mechanism comprises a compression spring disposed around the shaft and captured between an upper washer fixed to the shaft and a lower washer slidable on the shaft, such that when the U-shaped pawl cannot move past the intermediate position, the shaft of the linear actuator slides through the lower washer and through an opening in the U-shaped pawl to allow the shaft to move to the extended position, and the compression spring is compressed as the shaft slides and the upper washer moves toward the lower washer abutting against the U-shaped pawl, the compression spring acting on the lower washer,to provide the force on the U-shaped latch. [14] The actuated pawl assembly of claim 10, wherein the linear actuator is one selected from the group consisting of an electromagnetic actuator, a spindle actuator, a cam actuator, a hydraulic piston actuator, an air cylinder actuator, and a linear servo actuator. [15] An actuated pawl assembly according to claim 10, wherein the housing has two opposing pawl attachment locations, the U-shaped pawl being rotatably connectable to one of the two opposing pawl attachment locations to accommodate the direction of rotation of the rotating hub. [16] An actuated pawl assembly comprising: a rotating hub with several teeth and several tooth gaps, wherein the plurality of teeth are each separated by one of the plurality of tooth gaps; a housing, a two-part latch with an upper jaw and a lower jaw, both of which are rotatably connected to a common pivot pin connected to the housing, the two-part pawl being rotatable between a disengaged position, an engaged position and a ratchet mode, an upper seat of the upper jaw, a lower seat of the lower jaw; an actuator connected to the housing and having a shaft configured to contact the lower jaw when the shaft moves between a retracted position and an extended position, wherein the shaft, upon movement to the extended position, causes the shaft to apply a force to the two-piece pawl through contact between the shaft and the lower jaw to cause the two-piece pawl to move toward the rotating hub and move to the engaged position or the ratchet position. [17] The actuated pawl assembly of claim 17, further comprising a biasing member connected between the housing and the two-piece pawl for moving the two-piece pawl to the disengaged position when the shaft of the actuator moves to the retracted position. [18] The actuated pawl assembly of claim 17, further comprising a motion retention mechanism having a resilient spring positioned between an upper seat formed on the upper jaw and a lower seat formed on the lower jaw, thereby biasing the upper jaw and the lower jaw away from each other, the motion retention mechanism maintaining a force on the upper jaw against the rotating hub until the upper jaw moves to the engaged position. [19] The actuated pawl assembly of claim 17, wherein the actuator is a linear actuator selected from the group consisting of an electromagnetic actuator, a spindle actuator, a cam actuator, a hydraulic piston actuator, an air cylinder actuator, and a linear servo actuator. [20] The actuated pawl assembly of claim 17, wherein the shaft of the actuator has a shaft radius configured to contact a radius on the lower jaw when the shaft moves between a retracted position and an extended position, wherein the shaft, upon movement to the extended position, causes the shaft to apply a force to the two-piece pawl through contact between the shaft radius and the radius of the lower jaw, causing the two-piece pawl to move toward the rotating hub and move to the engaged position or the ratchet position. [21] An actuated pawl assembly according to claim 17, wherein the housing has two opposing pawl attachment locations, the two-part pawl being rotatably connectable to one of the two opposing pawl attachment locations to accommodate the direction of rotation of the rotating hub.