Disengagement and reengagement mechanism on motorized seating unit for selective manual control

Abstract

A motorized positioning apparatus for a seating unit includes a motor assembly that is configured to move a pair of linkage mechanisms though a series of positions that arrange the seating unit in a closed position, open position, or extended position. The motor assembly is selectively and releasably coupled to the linkage mechanisms, to allow the motor assembly to be de-coupled from the linkage mechanisms to allow the seating unit to be manually closed by a user.

Claims

1. A motorized positioning apparatus for a seating unit, the apparatus comprising: a pair of substantially mirror-image linkage mechanisms having a plurality of links controlling movement of an ottoman; a stationary rail coupled between the pair of linkage mechanisms; a motor tube coupled to at least one of the plurality of links of each linkage mechanism; a motor assembly comprising a body coupled to the stationary rail and a drive block slidably traversing the body; and a means for selectively and releasably coupling the drive block to the motor tube.

2. The motorized positioning apparatus of claim 1, wherein the means for selectively and releasably coupling the drive block to the motor tube and the stationary rail comprises a back plate coupled to the motor tube, and a pair of solenoid brackets selectively and releasably coupled to the motor tube and the drive block.

3. The motorized positioning apparatus of claim 2, wherein the drive block comprises a pair of mounting tabs, each mounting tab comprising an aperture; wherein the pair of solenoid brackets actuate a pair of pins to be received by the aperture of each mounting tab when the solenoid bracket is engaged; and further wherein the pair of solenoid brackets selectively and releasably couple the motor tube to the drive block by actuating the pair of pins to be received by the aperture in response to an input.

4. The motorized positioning apparatus of claim 3, further comprising a controller, wherein the input is received by the controller.

5. The motorized positioning apparatus of claim 2, wherein the back plate comprises a pair of adjustment slots extending vertically on the back plate to receive and couple the pair of solenoid brackets at a position to selectively and releasably couple the motor tube to the drive block.

6. The motorized positioning apparatus of claim 2, wherein the back plate comprises an opening to receive and support the body.

7. The motorized positioning apparatus of claim 1, wherein the motor assembly comprises a word gear and rack arrangement to slidably move the drive block across the body.

8. The motorized positioning apparatus of claim 1, wherein the means for selectively and releasably coupling the drive block to the motor tube and the stationary rail comprises at least one of a friction clutch, a sprag clutch, a spring loaded clutch, a magnetic clutch, a residual magnetic clutch, or a friction clutch.

9. A motorized positioning apparatus for a seating unit, the apparatus comprising: a pair of substantially mirror-image linkage mechanisms having a plurality of links controlling movement of an ottoman; a stationary rail coupled between the pair of linkage mechanisms; a motor tube coupled to at least one of the plurality of links of each linkage mechanism; a motor assembly comprising a body coupled to the stationary rail and a drive block slidably traversing the body, the drive block comprising a pair of mounting tabs, each mounting tab of the pair of mounting tabs comprising an aperture; a back plate coupled to the motor tube comprising a pair of adjustment slots; and a pair of solenoid brackets coupled to the back plate by the pair of adjustment slots, wherein engaging the pair of solenoid brackets actuates a pair of pins receivable by the aperture of each mounting tab to selectively and releasably couple the motor tube to the drive block.

10. The motorized positioning apparatus of claim 9, wherein the pair of adjustment slots couple the pair of solenoid brackets at a position to actuate the pair of pins to be receivable by the aperture.

11. The motorized positioning apparatus of claim 9, further comprising a controller for receiving an input, and wherein the input received by the controller engages the pair of solenoid brackets to actuate the pair of pins.

12. The motorized positioning apparatus of claim 9, wherein the motor assembly comprises a motor operable to move the drive block along the body.

13. The motorized positioning apparatus of claim 9, wherein the pair of adjustment slots extend vertically on the back plate; where the pair of solenoid brackets comprise mounting holes aligned with each of the pair of adjustment slots; and wherein the solenoid bracket is coupled to the back plate by an attaching mechanism using the holes and the pair of adjustment slots to vertically adjust the position of the solenoid bracket on the back plate.

14. The motorized positioning apparatus of claim 9, wherein the back plate further comprises an opening to receive the body.

15. The motorized positioning apparatus of claim 14, wherein the back plate is slidably moveable along the body moving the motor tube and the pair of mirror-image linkage mechanisms controlling movement of the ottoman.

16. A motorized positioning apparatus for a seating unit, the apparatus comprising: a pair of substantially mirror-image linkage mechanisms having a plurality of links controlling movement of an ottoman, a backrest, and a seat; a rear base rail coupled between the pair of linkage mechanisms; a motor tube coupled to at least one of the plurality of links of each linkage mechanism; a motor assembly comprising a body coupled to the rear base rail, a drive block, a pair of mounting tabs wherein each mounting tab of the pair of mounting tabs comprises an aperture, and a motor coupled to the drive block to slidably move the drive block along the body; a back plate coupled to the motor tube comprising an opening to receive the body and slidably move the back plate along the body moving the motor tube and the pair of mirror-image linkage mechanisms controlling movement of the seat, the ottoman, and the back; a pair of solenoid brackets coupled to the back plate, wherein engaging the pair of solenoid brackets actuates a pair of pins to be received by the aperture of each mounting tab; and a controller to receive an input and wherein the input received engages the pair of solenoid brackets to actuate the pair of pins from a selectively coupled state to a releasably coupled state for the motor tube to the drive block.

17. The motorized positioning apparatus of claim 16, wherein the selectively coupled state comprises engaging the pair of solenoid brackets to couple the motor tube to the drive block by actuating the pair of pins to be received by the aperture of each mounting tab.

18. The motorized positioning apparatus of claim 16, wherein the selectively coupled state enables movement of the drive block along the body to move the motor tube and actuate the pair of substantially mirror-image linkage mechanisms.

19. The motorized positioning apparatus of claim 16, wherein the releasably coupled state comprises disengaging the pair of solenoid brackets to move the motor tube free from the drive block by disengaging the pair of pins to retract from the aperture of each mounting tab.

20. The motorized positioning apparatus of claim 16, wherein the releasably coupled state enables movement of the motor tube independent of the drive block to actuate the pair of substantially mirror-image linkage mechanisms.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) This disclosure includes various details that may reference the attached drawing figures, which are incorporated herein by reference, wherein:

(2) FIG. 1 is a perspective view of a motorized multi-position seating unit, with one linkage mechanism not shown for clarity, with the seating unit in a closed position;

(3) FIG. 2 is a view, similar to that of FIG. 1, with the seating unit in a TV position, where the ottoman has been moved to an extended position and the backrest in the upright position;

(4) FIG. 3 is a view, similar to that of FIGS. 1 and 2, with the seating unit in a closed position and with the motor and drive block de-coupled from the motor tube and linkage mechanism;

(5) FIG. 4A is an enlarged view showing the drive block and motor de-coupled from the motor tube and linkage mechanism;

(6) FIG. 4B is a view similar to FIG. 4A, showing the drive block de-coupled from the motor tube and in a different position from that of FIG. 4A;

(7) FIG. 5 is a view similar to that of FIG. 4A showing, but showing the pins of the solenoids extended to couple the motor tube and linkage mechanism to the motor and drive block;

(8) FIG. 6 is an enlarged view of the back plate, shaft insert, guide block and solenoid brackets; and

(9) FIG. 7 is an exemplary view of a prior art motorized seating unit.

DETAILED DESCRIPTION

(10) Subject matter is described throughout this disclosure in detail and with specificity in order to meet statutory requirements. But the aspects described throughout this disclosure are intended to be illustrative rather than restrictive, and the description itself is not intended necessarily to limit the scope of the claims. Rather, the claimed subject matter might be practiced in other ways to include different elements or combinations of elements that are similar to the ones described in this disclosure and that are in conjunction with other present, or future, technologies. Upon reading the present disclosure, alternative aspects may become apparent to ordinary skilled artisans that practice in areas relevant to the described aspects, without departing from the scope of this disclosure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This principle is contemplated by and is within the scope of the claims.

(11) An example of a prior art motion furniture piece is shown and described in U.S. Pat. No. 9,845,852 (“the '852 patent”). As an example, FIG. 6 of the '852 patent is shown in simplified fashion here as FIG. 7, and shows one side of a motion furniture linkage mechanism (text notations have been added to FIG. 7 for explanatory purposes) in the closed position. The side not shown is a mirror-image of the side shown. The two linkage mechanisms are coupled together, such as with a stationary rail such as a rear base rail and/or a front base rail and a motor tube. Each end of the motor tube is coupled to a part of the linkage mechanism. The motor tube is also coupled to an actuator. The actuator (or motor) can be engaged to move a drive block forward, causing the linkage mechanisms to move from the closed position to the TV position to the reclined position. The actuator can also be engaged to move the drive block backward, causing the linkage mechanisms to move from the reclined position to the TV position to the closed position. In the prior art, the motor tube typically has a mounting bracket that is pivotally coupled to the drive block, such that the motor tube always moves with the drive block, and thus the linkage mechanisms always move with the drive tube. The mounting bracket is coupled to the drive block in a pivotal way, such as with a bolt or a clevis pin. This connection is permanent, in that to disengage the motor tube from the drive block requires access to the underside of the motion furniture, and generally requires some type of tool. In effect, this means that the only way to move the linkage mechanisms between the closed position, TV position and reclined position is to activate the actuator or motor to move the drive block and motor tube, thus moving the linkage mechanisms. As noted above, moving from the reclined position to the closed position may take more time than users want, in certain situations.

(12) Many embodiments are contemplated in the present application. As described, the pair of linkage mechanisms described herein may arrange a seating unit in a closed position, TV position, or an extended position. The linkage mechanisms may control the positioning of only the ottoman or a combination of the ottoman, a seat, and a backrest. In aspects where the linkage mechanism may only control the positioning of the ottoman, the backrest and the seat may be controlled by an independent linkage mechanism. Even in aspects where the linkage mechanism only controls the positions of the ottoman, the pair of linkage mechanisms may arrange only the ottoman in the closed position, TV position, or the extended position.

(13) FIG. 1 depicts a new coupling arrangement between the linkage mechanisms and the actuator. More specifically, FIG. 1 depicts a motorized seating unit 10, showing a linkage mechanism 12, which is operable to move the motorized seating unit 10 from a closed position (FIG. 1), to a TV position (FIG. 2) and to a reclined position (not shown), and back. Another linkage mechanism of the motorized seating unit 10 is not shown, but would be a mirror-image of the linkage mechanism 12. The linkage mechanism 12, and the opposite linkage mechanism are coupled together at one point by a rear base rail 14, which may be typically made from bent or formed metal. Although a stationary rail such as the rear base rail 14 is illustrated in at least FIG. 1 as coupling the linkage mechanisms together, in some aspects other stationary rails are contemplated to be used. A front base rail may couple the linkage mechanisms together, which may be located opposite the illustrated rear base rail towards the ottoman end of the linkage mechanism 12. In some aspects a combination of the front base rail and the rear base rail may couple the linkage mechanism together.

(14) At another point, the linkage mechanism 12, and the opposite linkage mechanism are coupled together by a motor tube 16. Each end of the motor tube 16 is coupled to a part of the respective linkage mechanism 12, such that, as the motor tube 16 moves, the linkage mechanism 12 moves the seating unit 10 between the closed, TV and reclined positions, and back.

(15) A motor (such an electric linear actuator) 18 is pivotally coupled to the rear base rail 14. For example, a rear motor mounting bracket 20 may be coupled to the rear base rail 14. Similarly, a motor housing 22 may have an integrally-formed bracket 24, or the bracket 24 may be coupled to the motor housing 22. The bracket 24 and the rear motor mounting bracket 20 may be pivotally coupled together, such as by placing a clevis pin 26 through holes in the bracket 24 and the rear motor mounting bracket 20. Other attachment arrangements could also be used to pivotally couple the motor 18 to the rear base rail 14.

(16) In some contemplated aspects, other stationary rails other than the rear base rail 14 may be pivotally coupled to the motor. It is contemplated herein that the motor 18 may pivotally be coupled to the front base rail, described herein.

(17) As best seen in FIG. 2, the motor 18 is operable to move a drive block 28 along a body 30 of the motor 18. In one aspect, the motor 18 utilizes a worm gear and rack arrangement to selectively move the drive block 28 forward or backward along the body 30. The body 39 may be coupled pivotally along with the motor 18 to a stationary rail such as the rear base rail 14 or the front base rail described herein. In some other aspects the body 30 couple the front and the rear base rails.

(18) As best seen in FIG. 4B, the drive block 28 is coupled to a pair of mounting tabs 32, or mounting tabs 32 could be integrally formed with the drive block 28. Each mounting tab 32 includes an aperture 34. Motor tube 16 has a mounting bracket 36 coupled to it, such as by welding, for example. The mounting bracket 36 has a pair of extensions that each have an aperture 38. Apertures 34 on mounting tabs 32 and apertures 38 on bracket 36 are used to selectively couple drive block 28 and motor 18 to motor tube 16 and linkage mechanisms 12.

(19) More specifically, as best seen in FIGS. 5 and 6, a back plate 40 is coupled to motor tube 16. Back plate 40, in some aspects, is made from a sturdy material, such as metal, and includes a first set of elongated slots 42. Slots 42 may be used, in some aspects, to bolt back plate 40 to motor tube 16. In some aspects, motor tube 16 may have corresponding threaded holes through which bolts 44 are threaded, or may have corresponding through-holes in a nut-and-bolt connection arrangement. As best seen in FIG. 6, back plate 40, in some aspects, has a first open section 46 and a second open section 48. As best seen in FIGS. 4A and 4B and 5, when back plate 40 is coupled to motor tube 16, first open section 46 allows mounting bracket 36 (coupled to motor tube 16) to extend through first open section 46. A shaft insert 50 is also coupled to back plate 40, in some aspects just below motor tube 16. Shaft insert 50 is also made of metal and has a generally u-shaped opening 52 formed therein that allows clearance for body 30 of motor 18. In some aspects, the surface of u-shaped opening 52 supports body 30 of motor 18. In some aspects, a guide block 54 is also coupled to back plate 40, on the side of back plate 40 opposite shaft insert 50. Guide block 54, in some aspects, is also made of a metal material. Shaft insert 50 and back plate 40 may, in some aspects, have aligned holes, which also align with threaded holes in guide block 54. Bolts may then be placed through the aligned holes in shaft insert 50 and back plate 40, and threaded into the threaded holes in guide block 54 to couple together the shaft insert 50, back plate 40 and guide block 54. Guide block 54 also has an open channel 56 that transitions to side guide surfaces 58 and bottom guide surface 60. In some aspects, open channel 56 corresponds to the size and shape of second open section 48 in back plate 40. Side guide surfaces 58 and bottom guide surface 60 could be formed as a bevel or chamfer.

(20) Returning to back plate 40, a first pair of adjustment slots 62 are cut or formed on one end of back plate 40 and a second pair of adjustment slots 64 are cut or formed on the other end of back plate 40. The first pair of adjustment slots 62 and the second pair of adjustment slots 64 extend vertically on back plate 40. The first pair of adjustment slots 62 are used to couple a first solenoid bracket 66 to the back plate 40. First solenoid bracket 66 has a first member 68 that is oriented orthogonally to a second member 70. First member 68 and second member 70 can be integrally formed, such as from bent metal or angle-iron. First member 68 has a number of spaced, threaded mounting holes 72 formed therein. Mounting holes 72 are located, in some aspects, such that two mounting holes 72 are aligned with each of the slots in the first pair of adjustment slots 62. Bolts or other attaching mechanisms can then be placed through the first pair of adjustment slots 62 and threaded into mounting holes 72 to secure first solenoid bracket 66 to back plate 40. The first pair of adjustment slots 62 allow the first solenoid bracket 66 to be adjusted vertically on the back plate 40. Second member 70 of the first solenoid bracket 66 includes a pair of slots 74 that extend orthogonally from the plane of back plate 40 when first solenoid bracket 66 is coupled to back plate 40.

(21) As best seen in FIG. 4A, a first solenoid 76 is supported on first solenoid bracket 66, and is coupled to first solenoid bracket 66 with bolts or screws, for example, using slots 74. As best seen in FIG. 5, first solenoid 76 includes a first pin 78. First solenoid 76 can be engaged to retract pin 78, or disengaged to allow pin 78 to extend from first solenoid 76. The reverse could also be true, in that first solenoid 76 could be engaged to extend pin 78 and disengaged to retract pin 78. In either case, first solenoid 76 is operable to actuate pin 78, for example, to selectively extend and retract pin 78.

(22) Similar to the discussion above, and as best seen in FIGS. 4A and 6, the second pair of adjustment slots 64 are used to couple a second solenoid bracket 80 to the back plate 40. Second solenoid bracket 80 has a first member 82 that is oriented orthogonally to a second member 84. First member 82 and second member 84 can be integrally formed, such as from bent metal or angle-iron. First member 82 has a number of spaced, threaded mounting holes 86 formed therein. Mounting holes 86 are located, in some aspects, such that two mounting holes 86 are aligned with each of the slots in the second pair of adjustment slots 64. Bolts or other attaching mechanisms can then be placed through the second pair of adjustment slots 64 and threaded into mounting holes 86 to secure second solenoid bracket 80 to back plate 40. The second pair of adjustment slots 64 allow the second solenoid bracket 80 to be adjusted vertically on the back plate 40. Second member 84 of the second solenoid bracket 80 includes a pair of slots 88 that extend orthogonally from the plane of back plate 40 when second solenoid bracket 80 is coupled to back plate 40. As best seen in FIG. 5, a second solenoid 90 is supported on second solenoid bracket 80, and is coupled to second solenoid bracket 80 with bolts or screws, for example, using slots 88. Second solenoid 90 includes a second pin 92. Second solenoid 90 can be engaged to retract pin 92, or disengaged to allow pin 92 to extend from second solenoid 90. The reverse could also be true, in that second solenoid 90 could be engaged to extend second pin 92 and disengaged to retract second pin 92. In either case, second solenoid 90 is operable to actuate pin 92, for example, to selectively extend and retract second pin 92.

(23) As shown in FIG. 1, first solenoid 76 and second solenoid 90 are coupled to a power source (not shown), a control box 93 and a controller 96. In one aspect, a release button 94 is added to controller 96 for the motorized seating unit 10. Release button 94 is used to communicate a desired change in state for first solenoid 76 and second solenoid 90, as further described below. Controller 96 may also have an open button 98 and a close button 100, for example. Controller 96 is, in some aspects, coupled to control box 93 that receives signals from controller 96 and passes them on to, for example, motor 18, first solenoid 76 and second solenoid 90.

(24) In a first state, (as shown in FIGS. 1, 2 and 5) the first pin 78 of first solenoid 76 and the second pin 92 of second solenoid 90 extend through respective apertures 34 on mounting tabs 32 and respective apertures 38 on bracket 36 thereby coupling drive block 28 and motor 18 to motor tube 16 and linkage mechanisms 12. In this first state, operation of the motor 18 moves the drive block 28 forwardly, such as when a user activates the open button 98, or rearwardly, such as when a user activates the close button 100. From the closed position, shown in FIG. 1, the user can activate the open button 98 to move to the TV position of FIG. 2 for example. Similarly, the user can active the close button 100 to move from the TV position to the closed position.

(25) If the motorized seating unit 10 is in the TV position of FIG. 2, for example, and the user wants to more-quickly exit the motorized seating unit 10 than would be possible using the close button 100 (and waiting for motor 18 to move drive block 28, motor tube 16 and linkage mechanisms 12 to their respective closed positions), the user can press the release button 94. This will change the state of first solenoid 76 and second solenoid 90 to retract first pin 78 and second pin 92, such that first pin 78 and second pin 92 no longer extend through respective apertures 34 on mounting tabs 32 and respective apertures 38 on bracket 36, thereby de-coupling drive block 28 and motor 18 from motor tube 16 and linkage mechanisms 12. In this second state, the user can apply a force to an ottoman link 102 (and the corresponding ottoman, not shown) of the linkage mechanism 12 to manually move the linkage mechanisms 12, and thus the motorized seating unit 10, to a closed position, such as shown in FIG. 3.

(26) Note that in FIG. 3, the drive block 28 remains in the position it was in in the TV position of FIG. 2, because the drive block 28 is de-coupled from motor drive tube 15. Upon activation of the release button, the control box 93 communicates with the motor 18 to move the drive block 28 to the closed position. FIG. 4B shows drive block 28 slightly before returning to the closed position, and FIG. 4A shows the drive block 28 returned to the closed position. With the linkage mechanisms 12 in the closed position (moved manually by the user), the respective apertures 34 on mounting tabs 32 and respective apertures 38 on bracket 36 are again aligned with first pin 78 and second pin 92. When the drive block 28 reaches the position corresponding to the closed position, the control box 93 signals the first solenoid 76 and the second solenoid 90 to return to the first state, moving first pin 78 and second pin 92 through respective apertures 34 and apertures 38 to re-couple drive block 28 and motor 18 from motor tube 16 and linkage mechanisms 12, such that the open button 98 and close button 100 can be used to move the drive block 28, and thus the linkage mechanisms 12 and seating unit 10 between the closed, TV and reclined positions. FIG. 5 shows first pin 78 and second pin 92 extending through apertures 34, 38 to re-coupled drive block 28 and motor 18 to motor tube 16 and linkage mechanisms 12. In one aspect, the control box 93 may also signal the motor 18 to “jog” or move the drive block 28 slightly forward and then slightly backward to ensure that the first pin 78 and second pin 92 have properly extended through respective apertures 34 and apertures 38.

(27) While first solenoid 76 and second solenoid 90 are described as moving first pin 78 and second pin 92 through apertures 34 and apertures 38, other connecting mechanisms could be used to selectively couple and de-couple drive block 28 and motor 18 to and from motor tube 16 and linkage mechanisms 12 from a remote location, such as a button on controller 96.

(28) Other aspects of coupling between the linkage mechanisms and the actuator are contemplated herein. Each of the aspects below may be used to couple the motor 18 to the drive block 28. The below references various features shown in FIGS. 1 and 2.

(29) A wrap-spring clutch may be used to couple the linkage mechanism to the actuator. In one aspect, the wrap-spring clutch may consist of an input and output hub that attach, respectively, to the motor 18 and drive block 28 to move the drive block 28 forward or backward along the body 30. A helical-wound spring may span the two hubs. The spring inside diameter may be slightly smaller than the outside diameter of the hubs to create an interference fit. Rotating the input hub in the direction of the spring helix may force the spring to wrap down onto the hubs, coupling the motor 18 and drive block 28 without slippage. Stopping the motor 18 or reversing its direction may unwrap the spring and releases the output hub, letting the drive block 28 freely rotate (overrun). Stated differently, wrap-spring clutches may be unidirectional.

(30) Another aspect of coupling between the linkage mechanism and the actuator includes a friction clutch. In one aspect, the friction clutch may consist of a receiving mechanism and an engaging mechanism that attach, respectively, to the motor 18 and the drive block 28 to move the drive block 28 forward or backward along the body. Engaging the receiving mechanism with the engaging mechanism may couple the receiving and engaging mechanisms, coupling the motor 18 to the drive block 28. In some embodiments, engaging the receiving mechanism with the engaging mechanism may include rotating the engaging mechanism to engage the receiving mechanism. For example, the engaging mechanism may be threaded and be rotated by the motor 18. In that same example, the receiving mechanism may be configured to receive the threaded engaging mechanism, coupling the coupled motor 18 and the drive block 28. In the same example, reversing the rotation of the engaging mechanism may uncouple the engaging mechanism from the receiving mechanism. Stated differently, friction clutches may be bi-directional.

(31) Another aspect of coupling between the linkage mechanism and the actuator includes the use of a magnetic clutch. In one aspect the magnetic clutch may consist of an armature and an output hub coupled, respectively, to the motor 18 and the drive block 28. The output hub may include a magnetic mechanism, such as a field coil, configured to engage the armature. When the output hub is engaged, a magnetic field may be generated to couple the armature to the output hub, in turn coupling the motor 18 and the drive block 28. The output hub may be disengaged, removing the magnetic field and uncoupling the armature to the output hub. The magnetic field may be generated using a electromagnet or permanent magnet.

(32) In one aspect using the magnetic clutch described above, a residual magnetic clutch may be used to couple the linkage mechanism and the actuator. Implementing a residual magnetic clutch, residual magnetic force may be provided to engage the output hub, and when the output hub is disengaged, magnetic force may be stored. In some aspects, the residual magnetic clutch may include a coil with a magnetization current to create a magnetic force to couple the armature with the output hub.

(33) In another aspect, a spring loaded clutch collet may be used coupling between the linkage mechanism and the actuator. In one aspect, the spring loaded clutch collet may include a round driving member and a receiving member. Each of the round driving member and the receiving member may be coupled, respectively, to the motor 18 and the drive block 28. A spring may be coupled to round driving member and fit closely around the round driving member. The receiving member may be configured to receive the spring and similarly the spring may closely fit around the round driving member. In some aspects the spring is not coupled to the receiving member. The round driving member may engage and couple the receiving member by rotating, via the motor 18, the coupled spring in the direction of the spring helix. When the spring is closely fit around the receiving member the spring may tighten, and couple the round driving member to the receiving member. The round driving member may similarly rotate the opposite direction to disengage the spring from the receiving member. In this way, the spring loaded clutch may couple and uncouple the motor 18 from the drive block 28.

(34) In yet another aspect of coupling between the linkage mechanism and the actuator, a sprag clutch (also referred to as a “one-way clutch”) may be implemented. The sprag clutch may include a driving unit and a receiving unit coupled, respectively, to the motor 18 and the drive block 28. The receiving unit may include a plurality of non-revolving asymmetric figure-eight shaped sprags or some other single direction elements. Each of the sprags may tilt slightly when a torque is applied opposite the single direction. The receiving unit may be configured to receive the drive block while engaging the sprags. For example, the sprags may tilt slightly when a torque is applied in a clockwise direction, but each of the sprags may slip or free-wheel when the torque is applied in a counter-clockwise direction. When the drive block rotates clockwise, via the motor 18, the sprags may tilt preventing the drive block from disengaging the receiving unit. In this way, the sprag clutch may couple the linkage mechanism and the actuator.

(35) From the foregoing, it will be seen that aspects herein are well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Since many possible aspects may be made without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.