A demolding device that removes a thin-walled part from a mold, the thin-walled part being tubular and having a partially open wall, the demolding device including: contour units that are located in a circumferential direction of the thin-walled part and each of which includes a contact structure that contacts an outer surface of the thin-walled part and moves in a thin-walled surface outward direction extending away from the outer surface of the thin-walled part; and a puller that engages with edges of the partially open wall of the thin-walled part and that applies a load to the thin-walled part, the load including a force component acting in the circumferential direction of the thin-walled part. In response to application of the load from the puller to the thin-walled part, each of the contour units moves the contact structure to keep the contact structure in contact with the thin-walled part.

BACKGROUND ART

1. Field of the Invention

The present disclosure relates to a demolding device that demolds a thin-walled part formed by molding.

2. Description of the Related Art

A method for removing a relatively large thin-walled part such as one for use as an aircraft fuselage from a cylindrical tubular mold or a circular cone-shaped mold is to disassemble the mold and demold the thin-walled part. Another exemplary method uses two edges of a cylindrical tubular skin having a partially open wall to demold the thin-walled part from inside the mold.

In the case where the wall thickness of a thin-walled part is extremely small relative to the diameter of the thin-walled part, the use of the demolding method of the above-mentioned literature could cause a local deformation of the circumferential portion of the thin-walled part.

SUMMARY

A demolding device of the present disclosure is a demolding device that removes a thin-walled part from a mold, the thin-walled part being tubular and having a partially open wall, the demolding device including: contour units that are located in a circumferential direction of the thin-walled part and each of which includes a contact structure that contacts an outer surface of the thin-walled part and moves in a thin-walled surface outward direction extending away from the outer surface of the thin-walled part; and a puller that engages with edges of the partially open wall of the thin-walled part and that applies a load to the thin-walled part, the load including a force component acting in the circumferential direction of the thin-walled part, wherein in response to application of the load from the puller to the thin-walled part, each of the contour units moves the contact structure to keep the contact structure in contact with the thin-walled part.

DETAILED DESCRIPTION

Hereinafter, a demolding device and a demolding method according to the present disclosure will be described with reference to the drawings. The demolding device and the demolding method described below are merely exemplary embodiments. It should be appreciated that the present disclosure is not limited to the embodiments described below.

First Embodiment

FIG.1Ais an overall perspective view showing the configuration of a demolding device100according to the present disclosure.FIG.1Bshows the demolding device100as viewed along the arrow S inFIG.1A. In the following description, two directions perpendicular to an axial direction Df of a tubular thin-walled part SP to be demolded by the demolding device100are referred to as a first perpendicular direction Ds and a second perpendicular direction Dt, respectively. For example, the first perpendicular direction Ds is the width direction of the thin-walled part SP, and the second perpendicular direction Dt is the up-down direction. In the case where the thin-walled part SP is shaped as a cylindrical tube, the first perpendicular direction Ds is the radial direction of the thin-walled part SP.

As shown inFIGS.1A and1B, the demolding device100is a device that removes the tubular thin-walled part SP having a partially open wall from a mold ML. The demolding device100includes outer frames10, connection structures11, frame support blocks20, a mold retainer30, a mold support block38, pullers40, contour units (contour structures)60, and control circuitry150.

Four outer frames10are aligned in the axial direction Df Two frame support blocks20are aligned in the axial direction Df. Two of the four outer frames10are supported by one of the frame support blocks20. The other two of the four outer frames10are supported by the other of the frame support blocks20. One of the two outer frames10supported by the one frame support block20is at a location corresponding to one end of the thin-walled part SP in the axial direction Df One of the two outer frames10supported by the other frame support block20is at a location corresponding to the other end of the thin-walled part SP in the axial direction Df.

Each of the outer frames10is, for example, U-shaped to open at one end in the second perpendicular direction Dt. The mold ML, with which the thin-walled part SP is in close contact, is located inside the U-shaped openings of the outer frames10. Each of the outer frames10supports contour units60. Any one of the outer frames10and another outer frame10adjacent to the one outer frame10are coupled by connection structures11extending in the axial direction Df. The outer frames10are not limited to the configuration described above. The outer frames10may be any kind of outer frames that have strength and stiffness sufficient for proper operation of the demolding device100.

The contour units60supported by each outer frame10are located in the circumferential direction of the thin-walled part SP. Each of the contour units60includes a contact structure59that contacts the outer surface SPf of the thin-walled part SP. Each of the contour units60supports the contact structure59, which can move in a thin-walled surface outward direction Dw extending away from the outer surface of the thin-walled part SP. In the present embodiment, the contact structure59is either a contour roller61or a contour board68. One of the outer frames10is at a location corresponding to one end of the thin-walled part SP in the axial direction Df Thus, the contact structure59of the contour unit60supported by the one outer frame10contacts one end of the outer surface SPf of the thin-walled part SP in the axial direction Df. Another of the outer frames10is at a location corresponding to the other end of the thin-walled part SP in the axial direction Df, and the contact structure59of the contour unit60supported by the other outer frame10contacts the other end of the outer surface SPf of the thin-walled part SP in the axial direction Df. Those locations in the axial direction Df at which the contact structures59contact the thin-walled part SP are not limited to the axial ends of the outer surface SPf. In response to load application from the pullers40to the thin-walled part SP, the contour units60move the contact structures59to keep the contact structures59in contact with the thin-walled part SP.

The mold support block38includes a support35, a support shaft36connected to the support35, and a support base37supporting the support shaft36. The mold support block38indirectly supports one end of the mold ML in the axial direction Df. Specifically, a connection ring CR having a smaller diameter than the mold ML is connected to the one end of the mold ML. The support35is arc-shaped and supports the connection ring CR. Thus, the one end of the mold ML is indirectly supported by the support35. The support shaft36extends in the second perpendicular direction Dt. In the present embodiment, the dimension of the support shaft36in the first perpendicular direction Ds is smaller than the dimension of the opening of the partially open wall of the thin-walled part SP in the first perpendicular direction Ds. This makes it possible to move and withdraw the demolded thin-walled part SP in the axial direction Df without having to detach the mold ML and the mold support block38from each other. The connection ring CR and the support35of the mold support block38may be detachably fastened by means such as bolts.

The mold retainer30supports the other end of the mold ML in the axial direction Df. For example, the mold retainer30is shaped as a hollow rectangular parallelepiped, and the inner wall of the mold retainer30supports the other end of the thin-walled part SP. The mold retainer30is not limited to having a particular structure. For example, the mold retainer30may have a framework structure made up of frames combined together. The connection between the mold retainer30and the other end of the mold ML in the axial direction Df is not limited to using particular means. For example, the mold retainer30and the mold ML may be connected by a portion of the frames of the framework structure mentioned above.

The pullers40are located in correspondence with the opposite ends of the thin-walled part SP in the axial direction Df Each of the pullers40engages with the opposite edges of the opening of the partially open wall of the thin-walled part SP and applies a load including a force component acting in the circumferential direction of the thin-walled part SP. Those locations at which the pullers40engage with the thin-walled part SP are not limited to the edges of the thin-walled part SP. For example, the pullers40may engage with the vicinities of the edges of the thin-walled part SP to apply loads.

FIG.2Ais a perspective view of the thin-walled part SP ofFIG.1A.FIG.2Bshows the thin-walled part SP ofFIG.2Aas viewed in the axial direction Df. The thin-walled part SP is used, for example, as an aircraft fuselage. As shown inFIG.2A, the thin-walled part SP is shaped as a tube having a partially open wall. The thin-walled part SP includes a first edge SPa and a second edge SPb. The first edge SPa and the second edge SPb are the edges of the opening of the partially open wall of the thin-walled part SP. The first edge SPa and the second edge SPb are opposite to each other in the first perpendicular direction Ds. The thin-walled part SP includes stringers ST joined to the inner surface of the thin-walled part Sp. As shown inFIG.2B, the wall thickness ts of the thin-walled part SP is, for example, from 1/3500 to 1/200 of the maximum width Wm of the hollow interior of the thin-walled part SP on the outer circumference of the mold. The thin-walled part SP may include another opening for a window or door. InFIG.2A, such an opening for a window or door in the thin-walled part SP is omitted.

The following will describe the contour units60. In the present embodiment, contour units60A or contour units60B may be used as the contour units60.FIG.3Ais a perspective view showing the configuration of the contour unit60A.FIG.3Bis a perspective view showing the configuration of the contour unit60B. There is no limitation on which of the contour units60located in the circumferential direction of the thin-walled part SP are the contour units60A or60B. Hereinafter, the configurations of the contour units60A and60B will be described with reference to the drawings.

The contour unit60A ofFIG.3Aincludes a pair of contour rollers61which are an example of the contact structures59, a pair of arms62, a coupler63, a slider64, a base65, and a cylinder66including a piston67. The control circuitry150controls the operation of the cylinder66.

One of the contour rollers61includes a rotatable axle61a, which is rotatably supported by one end of one of the arms62and one end of the other arm62. Likewise, the other contour roller61includes a rotatable axle61a, which is rotatably supported by the other end of the one arm62and the other end of the other arm62.

The coupler63couples the longitudinal center of the one arm62to the longitudinal center of the other arm62. The distal end of the slider64is connected to the coupler63. The slider64is connected to the base65and moves in the thin-walled surface outward direction Dw. To the slider64is secured the distal end of the piston67. In this configuration, the control circuitry150controls the cylinder66to move the piston67in the thin-walled surface outward direction Dw, and in conjunction with this movement the pair of contour rollers61move in the thin-walled surface outward direction Dw. The cylinder66may be any actuator that moves the piston67in the thin-walled surface outward direction Dw. For example, the cylinder66may be a hydraulic cylinder or a pneumatic cylinder.

The contour unit60B ofFIG.3Bhas substantially the same configuration as the contour unit60A ofFIG.3A. The components of the contour unit60B that are identical to components of the contour unit60A are denoted by the same reference signs as the components of the contour unit60A.

The contour unit60B includes a pair of contour boards68and a pair of arms62A instead of the contour rollers61, arms62, and rotatable axles61aof the contour unit60A. One of the contour boards68is connected between one end of one of the arms62A and one end of the other arm62A. The other contour board68is connected between the other end of the one arm62A and the other end of the other arm62A. The control circuitry150controls the cylinder66to move the piston67in the thin-walled surface outward direction Dw, and in conjunction with this movement the pair of contour boards68move in the thin-walled surface outward direction Dw.

A method for demolding the thin-walled part SP will be described with reference to the drawings.FIG.4Ashows the puller40in an initial position relative to the thin-walled part SP.FIG.4Bshows an engager41of the puller40which is in engagement with the first edge SPa of the thin-walled part SP.FIG.5Ashows the first edge SPa of the thin-walled part SP which is being expanded outward by the puller40.FIG.5Bshows the thin-walled part SP which has been demolded. The example illustrated inFIGS.4A to5Bis one in which the contour units60B as shown inFIG.3Bare used as the contour units60. InFIGS.4A to5B, only one half of the thin-walled part SP in the first perpendicular direction Ds is depicted for convenience of illustration. In reality, the other half of the thin-walled part SP, which is not shown in the figures, is demolded in the same manner as the one half of the thin-walled part SP.

As shown inFIGS.4A to5B, the puller40includes a pair of engagers41and an actuator43. The engagers41engage with the first edge SPa and the second edge SPb of the thin-walled part SP, respectively. The actuator43moves the engagers41. The actuator43is, for example, a hydraulic cylinder. The control circuitry150controls the operation of the actuator43.

As shown inFIG.4A, the thin-walled part SP formed by molding is initially supported in close contact with the mold ML. In this stage, the puller40is away from the first edge SPa of the thin-walled part SP.

Next, the actuator43is operated to move a slider45supporting the engager41outward in the first perpendicular direction Ds. Thus, as shown inFIG.4B, the engager41engages with the first edge SPa of the thin-walled part SP. The manner in which the puller40engages with the thin-walled part SP is not limited to that described above.

Next, as shown inFIG.5A, the actuator43moves the slider45further outward in the first perpendicular direction Ds. Thus, the first edge SPa of the thin-walled part SP expands outward in the first perpendicular direction Ds. Meanwhile, the contour units60are subjected to position change control by the control circuitry150. Thus, the contour boards68of the contour units60are moved in the thin-walled surface outward direction Dw.

From the state ofFIG.5A, the actuator moves the slider45further outward in the first perpendicular direction Ds. Meanwhile, as shown inFIG.5B, the control circuitry150moves the contour boards68are further in the thin-walled surface outward direction. The above operations are repeated until the thin-walled part SP is completely removed from the mold ML.

The control circuitry150controls the contour units60to change the position of. Specifically, under control of the control circuitry150, the contact structures59of the contour units60are moved in a direction extending outward from the wall of the thin-walled part SP along with the progress of demolding. The demolding device100effects the movement of the slider45in conjunction with the movement of the contact structures59of the contour units, thus keeping the contact structures59in contact with the outer surface SPf while performing the demolding process. The contact structures59of the contour units60, which are in contact with the outer surface SPf of the thin-walled part SP, slide in the circumferential direction of the thin-walled part SP and at the same time move in the direction extending outward from the wall of the thin-walled part SP. Specifically, the positions to which the contour rollers61or contour boards68are to be moved every time the slider45of the puller40moves the engager41are uniquely defined in association with the position to which the engager41is moved. The following is a detailed description of an example where the contour units60B including the contour boards68are used as the contour units60.

FIG.6Ashows an example where five contour units60B are located on the circumference of the thin-walled part SP. Each of the five contour units60B is denoted by the reference sign60E,60C, or60D to differentiate the contour units from one another in the following description. The contour unit60E is located diametrically opposite to the opening of the partially open wall of the thin-walled part SP. The two contour units60D are located symmetrically with respect to the contour unit60E in the first perpendicular direction Ds, and the other contour units60C are located symmetrically with respect to the contour unit60E in the first perpendicular direction Ds.

Several positions are predefined for the puller40and for each of the contour units60B. Four positions P0, P1, P2, and P3are defined for each slider45. Likewise, four positions Q0, Q1, Q2, and Q3are defined for the piston67of each of the contour units60C,60D, and60E. The position P0is the initial position of the slider45. The position Q0is the initial position of the piston67. When each slider45of the puller40is in the position P0, one of the engagers41is in engagement with the first edge SPa of the thin-walled part SP and the other engager41is in engagement with the second edge SPb. When the piston67of each contour unit60C,60D, or60E is in the position Q0, the contour board68of each contour unit60C,60D, or60E is in surface contact with the outer surface SPf of the thin-walled part SP.

When each slider45of the puller40moves from the position P0to the position P3in sequence, the piston67of each contour unit60C,60D, or60E takes a position in accordance with the position of the slider45. Specifically, as shown inFIG.6B, when each slider45of the puller40moves from the position P0to the position P1, the piston67of each contour unit60C moves to the position Q1, and the pistons67of the contour units60D and60E remain in the position Q0. The position information shown inFIG.6Bwhich specifies the positions of the contour units60C,60D, and60E in association with the different positions of the puller40is stored, for example, in a memory.

Subsequently, when each slider45of the puller40moves from the position P1to the position P2, the piston67of each contour unit60C moves from the position Q1to the position Q2. Meanwhile, the piston67of each contour unit60D moves from the position Q0to the position Q1. The piston67of the contour unit60E remains in the position Q0. In this way, the pistons67of the contour units60B move in accordance with the extent to which the thin-walled part SP expands along with the progress of demolding. The three positions P0to P2and the three positions Q0to Q2are merely examples, and the number of the positions may be freely chosen. The sliders45of the puller40and the pistons67of the contour units60B may be moved continuously.

As described above, the control circuitry150controls the amount of movement of the contact structure59of each of the contour units60B based on the memory-stored position information specifying the position of each contour unit60B in association with the position of the puller40. The memory may be included in the demolding device100separately from the control circuitry150. The movement of each slider45of the puller40and the movement of the piston67of each contour unit60B may be effected by means of gears or rods.

The outer frames10may be divisible frames.FIG.7shows a divisible outer frame10. As shown inFIG.7, the outer frame10includes a top portion10tat one end in the second perpendicular direction Dt. The top portion10tcan be divided into a first portion10aand a second portion10bin the first perpendicular direction Ds. A frame support block20for the first portion10aand another frame support block20for the second portion10bare aligned in the first perpendicular direction Ds. Each of the frame support blocks20slides on a base20ain the first perpendicular direction Ds. The division of the outer frame10into the first portion10aand the second portion10bmakes handling of the outer frame10easy. The first portion10aand the second portion10bmay be coupled, for example, by using a connector that extends on both the first portion10aand the second portion10band fastening the connector to the first portion10aand the second portion10bby means such as bolts.

Second Embodiment

As shown inFIGS.8A to9B, the contour boards68of the contour units60B may be used for one end region of the thin-walled part SP in the second perpendicular direction Dt, and the contour rollers61of the contour units60A may be used for the middle and lower regions of the thin-walled part SP in the second perpendicular direction Dt. When the thin-walled part SP is subjected to a pressure arising from the engagement of the engagers41of the puller40, the one end region of the thin-walled part SP is more resistant to deformation than the other end region of the thin-walled part SP and, on the one end region, unidirectional movement in the second perpendicular direction Dt away from the one end region is dominant over movement in the circumferential direction of the thin-walled part SP. The contour boards68are suitable for use on such a region where the unidirectional movement is dominant.

When the thin-walled part SP is subjected to a pressure arising from the engagement of the engagers41of the puller40, sliding movement in the circumferential direction of the thin-walled part SP is more dominant on the middle region and the other end region of the thin-walled part SP than on the one end region. The contour rollers61, which are more able to follow the motion of the thin-walled part SP than the contour boards68, are suitable for use on the regions where the sliding movement is dominant. The step shown inFIG.8Ais the same as the step ofFIG.4A, the step shown inFIG.8Bis the same as the step ofFIG.4B, the step shown inFIG.9Ais the same as the step ofFIG.5A, and the step shown inFIG.9Bis the same as the step ofFIG.5B.

As described above, the contour units60A and60B are configured to effect the sliding of the contact structures59on the thin-walled part SP by means of rotation of rollers or sliding of plates. The contour units60A and60B are not limited to the configurations described above and may have any configurations in which the sliding of the contact structures59is effected by means of rotation of rollers or sliding of plates. For example, the contour unit60A may include two or more contour rollers61or one contour roller61. For example, the contour unit60B may include two or more contour boards68or one contour board68. However, in the case where the contour units60A are configured as described above and their contour rollers61are arranged in the circumferential direction of the thin-walled part SP, a load can be applied distributively over the outer surface SPf of the thin-walled part SP. This can reliably prevent local deformation of the thin-walled part SP. For the same reason, the contour unit60B preferably includes two or more contour boards68or includes a contour board68shaped to extend in the circumferential direction of the thin-walled part SP.

The present disclosure is not limited to the above embodiments, and various modifications as described below may be made without departing from the gist of the present disclosure.

As shown inFIG.10A, the contour units60B may be used for a region of the circumference of the thin-walled part SP having a cross-section generally in the shape of a true circle, and the contour units60A may be used for the rest of the circumference of the thin-walled part SP. As shown inFIG.10B, the thin-walled part may be a thin-walled part SP1having a cross-section generally in the shape of a rectangle. When the thin-walled part SP1is viewed as divided into two portions in the second perpendicular direction Dt, the contour units60B may be used for one of the two portions, and the contour units60A may be used for the other of the two portions. As shown inFIG.10C, the thin-walled part may be a thin-walled part SP2having a cross-section generally in the shape of a rhombus. When the thin-walled part SP2is viewed as divided into two portions in the second perpendicular direction Dt, the contour units60B may be used for one of the two portions, and the contour units60A may be used for the other of the two portions. As shown inFIG.10D, the thin-walled part may be a thin-walled part SP3having a cross-section generally in the shape of an ellipse, and the contour units60A may be used for the entire circumference of the thin-walled part SP3.

Although inFIG.2Bthe first and second edges SPa and SPb of the thin-walled part SP are located at one end in the second perpendicular direction Dt, the present disclosure is not limited to this location of the first and second edges SPa and SPb. For example, the thin-walled part SP having the first and second edges SPa and SPb at the other end in the second perpendicular direction Dt or the thin-walled part SP having the first and second edges SPa and SPb at either end in the first perpendicular direction Ds can also be demolded by the demolding device100.

Although in the above embodiments two pullers40are located in the axial direction Df of the thin-walled part SP, the present disclosure is not limited to this puller arrangement. Three or more pullers40may be located in the axial direction Df.

Although in the above embodiments the thin-walled part SP to be demolded is one used as, for example, an aircraft fuselage, the present disclosure is not limited to this kind of thin-walled part SP. The demolding device100can demold the thin-walled part SP that is used, for example, as a nose or nacelle of an aircraft or as a fairing of a flying object.

In the above embodiments, whether demolding of the thin-walled part SP has been completed may be determined based on values detected by load cells located on the engagers41of the pullers40or may be confirmed visually.

The configuration for implementing the control by the control circuitry150is not limited to that illustrated above. The functionality of the elements disclosed herein may be implemented using circuitry or processing circuitry which includes general purpose processors, special purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuitry and/or combinations thereof which are configured or programmed to perform the disclosed functionality. Processors are considered processing circuitry or circuitry as they include transistors and other circuitry therein. In the disclosure, the circuitry, units, or means are hardware that carry out or are programmed to perform the recited functionality. The hardware may be any hardware disclosed herein or otherwise known which is programmed or configured to carry out the recited functionality. When the hardware is a processor which may be considered a type of circuitry, the circuitry, means, or units are a combination of hardware and software, the software being used to configure the hardware and/or processor.

A demolding device of the present disclosure is a demolding device that removes a thin-walled part from a mold, the thin-walled part being tubular and having a partially open wall, the demolding device including: contour units that are located in a circumferential direction of the thin-walled part and each of which includes a contact structure that contacts an outer surface of the thin-walled part and moves in a thin-walled surface outward direction extending away from the outer surface of the thin-walled part; and a puller that engages with edges of the partially open wall of the thin-walled part and that applies a load to the thin-walled part, the load including a force component acting in the circumferential direction of the thin-walled part, wherein in response to application of the load from the puller to the thin-walled part, each of the contour units moves the contact structure to keep the contact structure in contact with the thin-walled part.

According to the present disclosure, when the puller applies the load including a force component acting in the circumferential direction to the thin-walled part, the contact structure of each of the contour units follows the motion of the thin-walled part expanded outward by the applied load and maintains contact with the thin-walled part. This can prevent the thin-walled part from deforming due to the application of the load from the puller to the thin-walled part. Unlike in a conventional method where formation of a tubular part by thermal molding is followed by withdrawing the mold in the axial direction of the part, proper demolding can be accomplished even when the wall thickness of the tubular part varies in the axial direction or when an additional projecting part is located on a region of the inner wall surface of the tubular part.

In the above disclosure, the edges of the partially open wall of the thin-walled part may include a first edge and a second edge that are opposite to each other in a horizontal direction, the puller may include a pair of engagers that engage with the first edge and the second edge of the thin-walled part, and an actuator that moves the engagers, and the puller may move the engagers by operation of the actuator to apply the load to the thin-walled part.

According to the above disclosure, the load application to the thin-walled part is effected by the at least one pair of engagers moving in engagement with the first and second edges of the thin-walled part. Thus, the load including a force component acting in the circumferential direction of the thin-walled part can easily be applied to the thin-walled part.

In the above disclosure, the demolding device may further include control circuitry that controls the puller and the contour units, and the control circuitry may control an amount of movement of the contact structure of each of the contour units in conjunction with application of the load from the puller to the thin-walled part.

According to the above disclosure, the contact structure of each of the contour units can be moved to follow the motion of the thin-walled part expanded by application of the load including a force component acting in the circumferential direction to the first and second edges of the thin-walled part. This ensures the prevention of deformation of the thin-walled part.

In the above disclosure, the demolding device may further include a memory storing position information specifying positions of the contour units in association with a position of the puller, and the control circuitry may move the contact structure of each of the contour units based on the position information stored in the memory.

According to the above disclosure, the control circuitry can easily move the contact structures of the contour units.

In the above disclosure, the contact structure of each of the contour units may be a contour roller that moves on the thin-walled part or a contour board that comes into surface contact with the thin-walled part.

According to the above disclosure, the contour roller can be brought into contact with a region of the thin-walled part where sliding movement on the thin-walled part is relatively dominant when the load including a force component acting in the circumferential direction is applied to the thin-walled part, and the contour board can be brought into surface contact with another region of the thin-walled part where the sliding movement is not so dominant during the load application.

In the above disclosure, a wall thickness of the thin-walled part may be 1/3500 or more of a maximum width of a hollow interior of the thin-walled part on an outer circumference of the mold.

According to the above disclosure, the thin-walled part can be properly demolded even when the wall thickness of the thin-walled part is small.

Many modifications and other embodiments of the present disclosure will be apparent to those skilled in the art from the foregoing description. Accordingly, the foregoing description is to be construed as illustrative only, and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the disclosure. The details of the structure and/or function may be varied substantially without departing from the scope of the disclosure.