Patent Description:
In the fabrication of printed circuit boards, electronic components can be mounted to a printed circuit board by a process known as "wave soldering. " In a typical wave solder machine, a printed circuit board (sometimes referred to as a "PCB") is moved by a conveyor on an inclined path past a fluxing station, a pre-heating station, and finally a wave soldering station. At the wave soldering station, a wave of solder is caused to well upwardly (by means of a pump) through a wave solder nozzle and contact portions of the printed circuit board to be soldered.

Typical wave solder nozzles have exit wings that are manually tilted to increase or decrease the height of the back of the nozzle that controls the solder flow generated by the wave soldering machine. The process of adjusting the solder flow can be difficult and imposes risks to operators tasked with making such adjustments within a solder pot filled with molten solder. <CIT> relates to an apparatus for wave soldering and discloses a wave solder nozzle assembly comprising a rotatable exit wing, which can be adjusted or rotated to adjust the height of the solder wave by rotating a shaft which shaft is provided with at least one protruding member or cam. The at least one protruding member or cam raises or lowers the exit wing. <CIT> relates to a wave older nozzle with automated adjustable sliding plate.

One aspect of the disclosure is directed to a wave soldering machine to perform a wave soldering operation on a printed circuit board. In one embodiment, the wave soldering machine comprises a housing, a conveyor coupled to the housing, and a wave soldering station coupled to the housing. The conveyor is configured to deliver a printed circuit board through the housing. The wave soldering station includes a reservoir of solder material, and a wave solder nozzle assembly configured to create a solder wave. The wave solder nozzle assembly has a nozzle core frame and an exit wing. The exit wing is rotatable about a hinge with respect to the nozzle core frame to adjust a flow of a solder wave. The wave solder nozzle assembly further has a linear actuator connected to the exit wing and configured to adjust an orientation of the exit wing with respect to the nozzle core frame.

The linear actuator is connected to the exit wing by a linkage.

The exit wing includes a first end coupled by the hinge to the nozzle core frame and a second end, and the linkage includes at least one rotating link having a first end rotatably coupled to the second end of the exit wing and a second end that is rotatably coupled to an actuator arm of the actuator.

The linkage further includes a cross bar extending perpendicularly to and being rotatably coupled to the at least one rotating link, and at least one connecting link coupling the cross bar to the actuator arm and extending perpendicularly to cross bar.

The at least one connecting link is connected to the actuator arm by an actuator block.

In some embodiments, the at least one rotating link is two rotating links and the at least one connecting link is two connecting links.

In some embodiments, the wave soldering machine further comprises a controller in communication with the actuator and configured to cause the actuator to adjust the orientation of the exit wing during operation of the wave soldering machine.

In some embodiments, the wave soldering machine further comprises a substantially gas impermeable shroud that surrounds the wave soldering station and includes at least one sealed opening through which the at least one connecting link extends, each sealed opening having an inner surface that is in substantial sealing engagement with an outer surface of a respective one of the connecting links.

Another aspect of the disclosure is directed to a wave solder nozzle assembly of a wave soldering station configured to perform a wave soldering operation on a printed circuit board. According to the invention, the wave solder nozzle assembly comprises a nozzle core frame, an exit wing coupled to the nozzle core frame, the exit wing being rotatable about a hinge with respect to the nozzle core frame to adjust a flow of a solder wave, and a linear actuator connected to the exit wing and configured to adjust an orientation of the exit wing with respect to the nozzle core frame.

The exit wing includes a first end coupled by the hinge to the nozzle core frame and a second end, and wherein the linkage includes at least one rotating link having a first end rotatably coupled to the second end of the exit wing and a second end that is rotatably coupled to an actuator arm of the actuator.

In some embodiments, the actuator is configured to receive commands from a controller to cause the actuator to adjust the orientation of the exit wing during operation of the wave soldering machine.

In some embodiments, the wave solder nozzle assembly further comprises a substantially gas impermeable shroud that surrounds the wave soldering station and includes at least one sealed opening through which the at least one connecting link extends, each sealed opening having an inner surface that is in substantial sealing engagement with an outer surface of a respective one of the connecting links.

Another aspect of the disclosure is directed to a method of adjusting a flow of a solder wave of a wave solder nozzle assembly of a wave soldering machine. In one embodiment, the method comprises delivering solder material to a wave solder nozzle assembly including a nozzle core frame and an exit wing hingedly attached to the nozzle core frame, adjusting a flow of the solder wave by a linear actuator connected to the exit wing to adjust an orientation of the exit wing with respect to the nozzle core frame, and performing a wave soldering operation on a printed circuit board.

In some embodiments, adjusting the flow of the solder wave is achieved by rotating the exit wing with respect to the nozzle core frame by a linkage coupled to the linear actuator and the exit wing.

In some embodiments, the method further comprises creating a substantially gas impermeable atmosphere over the solder wave by a shroud that surrounds the wave soldering station that includes the wave solder nozzle assembly, the shroud including at least one sealed opening through which the at least one connecting link of the linkage extends, each sealed opening having an inner surface that is in substantial sealing engagement with an outer surface of a respective one of the connecting links.

In some embodiments, the actuator is coupled to a controller to control the movement of the linear actuator.

This disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The use of "including," "comprising," "having," "containing," "involving," and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The present disclosure provides a wave soldering machine including a wave solder nozzle assembly.

The present disclosure also provides a wave solder nozzle assembly for a wave soldering machine. The wave solder nozzle assembly includes an actuator that is configured for real-time control of an angle of an adjustable exit wing of the wave solder nozzle assembly. The angle of the exit wing affects the flow of a solder wave exiting the wave solder nozzle assembly.

In some embodiments, the actuator is a linear actuator that is coupled to the exit wing to adjust the angle of the exit wing. In some embodiments, the linear actuator includes one or more longitudinally movable actuator arms. Because the actuator arms move in a linear path, the linear actuator can be used in conjunction with a substantially gas impermeable shroud that surrounds the wave solder nozzle assembly. In some embodiments, the shroud is a substantially nitrogen impermeable shroud. In some embodiments, the shroud includes one or more sealed openings, each in sealing engagement with an outer surface of a respective one of the connecting links. In such embodiments, the outer surface of each connecting link has a substantially constant cross section along a length of the respective actuator arm that will pass through the respective sealed opening during use. Thus, the outer surface of the respective connecting link can maintain a seal with the respective sealed opening as the actuator arm is extended and retracted to rotate the exit wing. Such a sealing engagement of the shroud is not possible with rotating actuator arms that would sweep through a plane of the shroud.

Additionally, compared to other means of moving an exit wing, the linear actuator allows for a more compact linkage coupling the actuator arms to the exit wing.

Additionally, compared to other means of moving an exit wing, a controller can be automated to cause the linear actuator to adjust the orientation of the exit wing, thereby eliminating the need for manual intervention to change the orientation of the exit wing. The linear actuator can be controlled to precisely adjust the orientation of the exit wing during operation of the wave solder nozzle assembly.

For purposes of illustration, and with reference to <FIG>, embodiments of the present disclosure will now be described with reference to a wave solder machine, generally indicated at <NUM>, which is used to perform a solder application on a printed circuit board <NUM>. The wave solder machine <NUM> is one of several machines in a printed circuit board fabrication/assembly line. As shown, the wave solder machine <NUM> includes a housing or frame <NUM> adapted to house the components of the machine. The arrangement is such that a conveyor <NUM> delivers printed circuit boards to be processed by the wave solder machine <NUM>. Upon entering the wave solder machine <NUM>, each printed circuit board <NUM> travels along an inclined path (e.g., six degrees with respect to horizontal) along the conveyor <NUM> through a tunnel <NUM>, which includes a fluxing station, generally indicated at <NUM>, and a pre-heating station, generally indicated at <NUM>, to condition the printed circuit board for wave soldering. Once conditioned (i.e., heated), the printed circuit board <NUM> travels to a wave soldering station, generally indicated at <NUM>, to apply solder material to the printed circuit board. A controller <NUM> is provided to automate the operation of the several stations of the wave solder machine <NUM>, including but not limited to the fluxing station <NUM>, the pre-heating station <NUM>, and the wave soldering station <NUM>, in the well known manner.

Referring to <FIG>, the fluxing station <NUM> is configured to apply flux to the printed circuit board as it travels on the conveyor <NUM> through the wave solder machine <NUM>. The pre-heating station includes several pre-heaters (e.g., pre-heaters 22a, 22b and 22c), which are designed to incrementally increase the temperature of the printed circuit board as it travels along the conveyor <NUM> through the tunnel <NUM> to prepare the printed circuit board for the wave soldering process. As shown and described in greater detail below, the wave soldering station <NUM> includes a wave solder nozzle assembly in fluid communication with a reservoir of solder material. A pump is provided within the reservoir to deliver molten solder material to the wave solder nozzle assembly from the reservoir. Once soldered, the printed circuit board exits the wave solder machine <NUM> via the conveyor <NUM> to another station provided in the fabrication line, e.g., a pick-and-place machine.

In some embodiments, the wave solder machine <NUM> further may include a flux management system, generally indicated at <NUM>, to remove volatile contaminants from the tunnel <NUM> of the wave solder machine. As shown in <FIG>, the flux management system <NUM> is positioned below the pre-heating station <NUM>. In one embodiment, the flux management system is supported by the housing <NUM> within the wave solder machine, and is in fluid communication with the tunnel <NUM>, which is schematically illustrated in <FIG>. The flux management system <NUM> is configured to receive contaminated gas from the tunnel <NUM>, treat the gas, and return clean gas back to the tunnel. The flux management system <NUM> is particularly configured to remove volatile contaminants from the gas, especially in inert atmospheres.

Referring additionally to <FIG> and <FIG>, in one embodiment, the wave soldering station <NUM> includes a solder pot <NUM> that defines a reservoir <NUM> configured to contain molten solder. In one embodiment, the solder pot <NUM> is a box-shaped structure that supports the components of the wave soldering station <NUM> including a flow duct <NUM> having two chambers within the reservoir <NUM>. The flow duct <NUM> is designed to deliver pressurized molten solder to an opening or nozzle of a wave solder nozzle assembly, which is generally indicated at <NUM>. As will be described in greater detail below, the wave solder nozzle assembly <NUM> is configured to channel the molten solder to the bottom of the printed circuit board <NUM> and provides for smooth flow of solder back into the reservoir <NUM>. Specifically, the wave solder nozzle assembly <NUM> is capable of adjusting a flow of the solder wave when performing a wave solder operation.

The wave soldering station <NUM> further includes a pump impeller <NUM> positioned within the reservoir <NUM> of the solder pot <NUM> adjacent an inlet provided in the flow duct <NUM>. The pump impeller <NUM> pressurizes the molten solder in the reservoir <NUM> to pump the molten solder vertically within the flow duct <NUM> in the reservoir <NUM> to the wave solder nozzle assembly <NUM>. In one embodiment, the pump impeller <NUM> is a centrifugal pump that is suitably sized to pump the molten solder to the nozzle of the wave solder nozzle assembly <NUM>. The wave solder nozzle assembly <NUM> is configured to generate a solder wave that is provided to attach components on the circuit board <NUM> in the manner described below, and to optimize a dwell time during processing.

Referring to <FIG>, the wave solder nozzle assembly <NUM> includes a nozzle core frame <NUM> having two side walls <NUM>, <NUM>, a first longitudinal support element <NUM> and a second longitudinal support element <NUM> that extend between the side walls <NUM>, <NUM>. As shown, the nozzle core frame <NUM> further may include several cross support elements, each indicated at <NUM>, that extend between the first longitudinal support element <NUM> and the second longitudinal support element <NUM>. The nozzle core frame <NUM> also directs the solder flow through a nozzle throat defined between the first and second longitudinal support elements <NUM>, <NUM>.

The nozzle assembly <NUM> further includes an exit wing <NUM> to control the solder flow over the back of the nozzle of the solder wave generated by the wave solder machine <NUM>. To allow for an adjustment of the flow of the solder wave exiting the nozzle throat of the nozzle core frame <NUM>, the exit wing <NUM> is secured to the nozzle core frame <NUM> by a hinge <NUM>. The exit wing <NUM> is rotatable about the hinge <NUM> by an actuator <NUM> via a linkage. As described in more detail below, the angle of the exit wing <NUM> relative to the nozzle core frame <NUM> can be controlled in real-time by controlling the longitudinal displacement of an actuator arm <NUM> of the actuator <NUM> and thus the flow of the solder wave over the back of the nozzle to increase or decrease.

The actuator <NUM> is secured to the solder pot <NUM> by an actuator support frame <NUM>, which is secured to a side wall of the solder pot <NUM> by suitable fasteners, such as bolts. The actuator support frame <NUM> could alternately be secured to the solder pot <NUM> by another method, such as welding or rivets. As shown, the actuator <NUM> is secured to the actuator support frame <NUM>, which is configured to support the actuator firmly relative to the solder pot <NUM>. The actuator <NUM> is positioned next to the wave solder nozzle assembly <NUM> and forms part of the assembly to adjust an orientation of the exit wing <NUM> of the wave solder nozzle assembly with respect to the nozzle core frame <NUM> via the linkage coupled to the exit wing <NUM> and to the actuator <NUM>. The actuator includes the actuator arm <NUM> that is coupled to the linkage by an actuator block <NUM>. The linkage is described in more detail below.

In one embodiment, the actuator <NUM> is a linear actuator, so the actuator arm <NUM> moves in a longitudinal direction. The actuator block <NUM> connects the actuator arm <NUM> to connecting links <NUM> of the linkage to transfer movement from the actuator arm <NUM> to the connecting links <NUM>. Thus, longitudinal movement of the actuator arm <NUM> moves the actuator block <NUM> and the connecting links <NUM> in the same longitudinal direction as the actuator arm <NUM>. In some embodiments, the actuator <NUM> and the connecting links <NUM> are oriented so the actuator arm <NUM> moves the connecting links <NUM> in a horizontal direction. In certain embodiments, the actuator <NUM> includes an electromechanical actuator that provides movement for the adjustment of the orientation of the exit wing. The actuator <NUM> is driven by computer controlled machine software (supported by the controller <NUM>) and incorporates an encoder that can relay position indication to the machine software. Via the controller <NUM>, the actuator <NUM> can be controlled in real-time to achieve a desired orientation of the exit wing <NUM>. The controller is in communication with the actuator and is configured to cause the actuator to adjust the orientation of the exit wing <NUM> during operation of the wave soldering machine. In turn, the actuator <NUM> is configured to receive commands from the controller <NUM> to cause the actuator <NUM> to adjust the orientation of the exit wing <NUM> during operation of the wave soldering machine.

In one embodiment, the exit wing <NUM> includes a first end <NUM> that is coupled to the nozzle core frame <NUM> by the hinge <NUM> and a second end <NUM> that is coupled to the actuator via two rotating links <NUM> of the linkage so the actuator <NUM> can cause the second end of the exit wing to rotate about the hinge <NUM> at the first end <NUM> of the exit wing <NUM>. Rotating the exit wing <NUM> about the hinge <NUM> changes the flow of the solder wave passing over the exit wing <NUM>. In particular, rotating the exit wing <NUM> so the second end <NUM> of the exit wing <NUM> moves upwardly causes the flow of the solder wave over the exit wing to decrease while rotating the exit wing <NUM> so the second end <NUM> of the exit wing <NUM> moves downwardly causes the flow of the solder wave over the exit wing to increase.

As mentioned above, the linkage allows the actuator to adjust an orientation of the exit wing <NUM> with respect to the nozzle core frame. In particular, the linkage allows longitudinal movement of the actuator arm <NUM> of the actuator <NUM> to adjust an angle of an upper surface <NUM> of the exit wing <NUM> with respect to a horizontal direction. The linkage includes the two rotating links <NUM>, a cross bar <NUM>, and the two connecting links <NUM>. The two rotating links <NUM> couple the second end <NUM> of the exit wing <NUM> to the cross bar <NUM>, which is in turn coupled to the actuator block <NUM> by the two connecting links <NUM>.

Each rotating link <NUM> has a first end that is rotatably coupled to the second end of the exit wing <NUM> and a second end that is rotatably coupled to the cross bar <NUM>. The cross bar <NUM> extends perpendicularly to the rotating links <NUM>. Each connecting link <NUM> has a first end that is coupled to the cross bar <NUM> and a second end that is coupled to the actuator block <NUM>. The connecting links <NUM> extend perpendicularly to the cross bar <NUM> and parallel to the actuator arm <NUM>. As shown in <FIG>, when the upper surface <NUM> of the exit wing <NUM> extends substantially in a horizontal direction, the cross bar <NUM> is located beneath the exit wing <NUM> and longitudinally between the first end <NUM> of the exit wing <NUM> and the second end <NUM> of the exit wing <NUM>.

The longitudinal displacement of the actuator arm <NUM> is able to cause the exit wing <NUM> to rotate about the hinge <NUM>. An axial direction of the actuator arm <NUM> is parallel with an axial direction of each of the connecting links <NUM>. Thus, the actuator arm <NUM> is configured to move the connecting links <NUM> along the horizontal direction along the axis of the direction of the actuator arm <NUM>. Because the cross bar <NUM> is coupled to the connecting links <NUM>, extension or retraction of the actuator arm <NUM> results in translation of the cross bar <NUM>. Because the rotating links <NUM> are rotatably coupled to the cross bar <NUM> and because both the actuator <NUM> and the wave solder assembly <NUM> are secured to the solder pot <NUM>, this translation of the cross bar <NUM> results in a rotation of the exit wing <NUM>.

Referring particularly to <FIG> and <FIG>, the actuator arm <NUM> is shown in an extended position in <FIG> relative to the retracted position shown in <FIG>. The second end <NUM> of the exit wing <NUM> is shown to be higher in <FIG> than in <FIG>. A back gate <NUM> is secured to the second end <NUM> of the exit wing <NUM>. The controller <NUM> is configured to adjust the orientation of the exit wing <NUM> to change the flow of solder over the back gate <NUM> of the exit wing. The controller <NUM> is configured to achieve optimum soldering characteristics of the wave nozzle assembly <NUM>. Optimal soldering characteristics are achieved when there is no flow over the back gate <NUM> when the conveyor <NUM> is not carrying parts to be soldered, such as PCBs, over the wave solder assembly <NUM>, but, once a PCB carried by the conveyor <NUM> enters the solder wave, the solder starts to flow over the back gate <NUM> at the same velocity as the velocity of the PCB along the conveyor <NUM>. Once the PCB exits the wave, the solder flow over the back gate <NUM> stops again.

Due to the position of the actuator arm <NUM> in <FIG>, the upper surface <NUM> of the exit wing <NUM> extends in a substantially horizontal direction, which yields a solder wave having a first flow over the exit wing. The broken line arrows in <FIG> show the direction of solder flow through the wave solder assembly <NUM> when no parts to be soldered, such as PCBs, are passing along the conveyor <NUM> and the actuator arm <NUM> is in the extended position of <FIG>. The solder wave height in <FIG> is shown by the broken line A. In some embodiments, this solder wave height A is a minimum solder wave height of the wave solder assembly <NUM>. Due to the position of the actuator arm <NUM> in <FIG>, the upper surface <NUM> of the exit wing forms an angle with the horizontal direction that yields a solder wave having a second flow over the exit wing that is less than the first flow. The broken line arrows in <FIG> show the direction of solder flow through the wave solder assembly <NUM> when no PCBs are passing along the conveyor <NUM> and the actuator arm <NUM> is in the retracted position of <FIG>. The solder wave height in <FIG> is shown by the broken line B. In some embodiments, this solder wave height B is a maximum solder wave height of the wave solder assembly <NUM>.

Although the above description of solder flow relates to PCBs being carried by the conveyor <NUM>, similar solder flow would occur for other parts to be soldered that are carried by the conveyor <NUM> over the wave solder nozzle assembly <NUM>.

The orientations of the exit wing <NUM> that are shown in <FIG> and <FIG> are just two examples of orientations of the exit wing <NUM>. The rotational range of the exit wing <NUM> may be selected according to the desired performance parameters of the system, such as the desired range of wave heights. In various embodiments, the range of rotation of the exit wing <NUM> can extend beyond the orientations shown in <FIG> and <FIG>.

In some embodiments, the wave solder nozzle assembly <NUM> further includes a dross damper that is secured to the nozzle frame and configured to reduce turbulence as the solder travels back to the reservoir <NUM>, thereby reducing solder balls that can form within the reservoir. One or more nitrogen tubes can be provided to create an inert atmosphere during the wave soldering process.

In some embodiments, a shroud <NUM>, partially shown in <FIG> and <FIG>, extends around the wave solder nozzle assembly <NUM>. In some embodiments, the shroud <NUM> surrounds the wave solder nozzle assembly to create a substantially gas impermeable, inert atmosphere surrounding the solder wave. In some embodiments, the shroud <NUM> is substantially nitrogen impermeable. The shroud <NUM> includes two sealed openings <NUM> through which the connecting links <NUM> extend. Each sealed opening <NUM> has an inner surface <NUM> that is in substantial sealing engagement with an outer surface <NUM> of a respective one of the connecting links <NUM>. Because each connecting link <NUM> has a substantially constant cross section over a portion of the connecting link <NUM> that passes through the sealed opening <NUM>, the connecting link <NUM> is able to substantially form a gas impermeable seal with the inner surface <NUM> of the respective sealed opening. In some embodiments, the inner surface <NUM> of each sealed opening <NUM> is annular and the outer surface <NUM> of each connecting link <NUM> has a matching circular profile so the inner surface <NUM> is in substantial sealing engagement with the outer surface <NUM> as each connecting link <NUM> moves along an axial direction of the connecting link <NUM> through the sealed opening <NUM>.

The present disclosure also provides a method of adjusting a flow of a solder wave of a wave solder nozzle assembly of a wave soldering machine. In some embodiments, the method can be performed using the wave soldering station <NUM> or the wave soldering machine <NUM> including the wave soldering station <NUM> described above.

In some embodiments, the method comprises delivering solder material to the wave solder nozzle assembly <NUM> including the nozzle core frame <NUM> and an exit wing <NUM> hingedly attached to the nozzle core frame <NUM>, adjusting the flow of the solder wave by causing the linear actuator <NUM> connected to the exit wing <NUM> to adjust the orientation of the exit wing <NUM> with respect to the nozzle core frame <NUM>, and performing a wave soldering operation on a printed circuit board.

In some embodiments, adjusting the flow of the solder wave is achieved by rotating the exit wing <NUM> with respect to the nozzle core frame <NUM> by the linkage coupled to the linear actuator <NUM> and the exit wing <NUM>. In some embodiments, the linkage includes the connecting links <NUM> and the rotating links <NUM>, and the method includes causing translational movement of the connecting links <NUM> along an operational axis of the linear actuator <NUM> to cause a rotation of the rotating links <NUM>.

In some embodiments, the method includes creating a substantially gas impermeable atmosphere over the solder wave. In some embodiments, this is accomplished by the shroud <NUM> that surrounds the wave soldering station <NUM>. The shroud <NUM> includes at least one sealed opening <NUM> through which a respective connecting link <NUM> of the linkage extends. In some embodiments, the shroud <NUM> includes two sealed openings <NUM>. A first one of the connecting links <NUM> extends through a first one of the sealed openings <NUM> and a second one of the connecting links <NUM> extends through a second one of the sealed openings <NUM>. The inner surface <NUM> of each sealed opening <NUM> is in substantial sealing engagement with the outer surface <NUM> of the respective connecting link <NUM>.

In some embodiments of the method, the actuator <NUM> is coupled to the controller <NUM> to control the movement of the linear actuator <NUM>.

As used herein, "solder wave height" describes a vertical dimension of the solder wave.

Having thus described several aspects of at least one embodiment of this disclosure, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art, without departing from the scope of the appended claims.

Claim 1:
A wave solder nozzle assembly (<NUM>) for a wave soldering station configured to perform a wave soldering operation on a printed circuit board (<NUM>), the wave solder nozzle assembly comprising:
a nozzle core frame (<NUM>);
an exit wing (<NUM>) coupled to the nozzle core frame, the exit wing being rotatable about a hinge (<NUM>) with respect to the nozzle core frame to adjust a flow of a solder wave; and
a linear actuator (<NUM>) connected to the exit wing and configured to adjust an orientation of the exit wing with respect to the nozzle core frame;
wherein the linear actuator (<NUM>) is connected to the exit wing by a linkage;
wherein the exit wing includes a first end (<NUM>) coupled by the hinge to the nozzle core frame and a second end (<NUM>), and wherein the linkage includes at least one rotating link (<NUM>) having a first end rotatably coupled to the second end of the exit wing and a second end (<NUM>) that is rotatably coupled to an actuator arm (<NUM>) of the actuator (<NUM>);
wherein the linkage further includes a cross bar (<NUM>) extending perpendicularly to and being rotatably coupled to the at least one rotating link, and at least one connecting link (<NUM>) coupling the cross bar (<NUM>) to the actuator arm (<NUM>) and extending perpendicularly to cross bar (<NUM>);
wherein the at least one connecting link (<NUM>) is connected to the actuator arm (<NUM>) by an actuator block (<NUM>).