BACKGROUND OF THE INVENTION Cardboard boxes, cartons, and cases are widely used for holding many products, including but not limited to powdered detergents, sugar, flour, and packaged products. It is especially important to achieve a good seal on boxes that contain powdered materials and other fine products, otherwise, these materials will leak from the boxes. That is, these boxes should be "sift proof'. In these boxes, or in boxes for other products, it may be equally important for the boxes to be sealed sufficiently to keep bugs and other pests from coming inside the boxes. That is, these boxes may also need to be infestation proof.

The process of making boxes generally involves folding and sealing the flaps on the boxes, such as with glue to form the box into a closed and sealed configuration. Currently, boxes are sealed with relatively complex and expensive glue guns. Often, the applicators are stationary devices (glue guns) that apply glue to moving carton flaps with a doctor blade. The doctor blade contains a series of narrow, rectangular channels that form orifices. The orifices are arranged in a line that is perpendicular to the direction of carton travel. As the carton flaps move past the glue gun, a series of valves open at various times to allow glue to be extruded from the orifices.

Thin films of glue are then wiped or smeared onto the passing carton flaps to form"U"or"H"- shaped plan view patterns on the carton flaps that are used to seal the flaps in a closed configuration. Aside from the complexity and expense of this type of apparatus, the narrow glue channels in the doctor blades are easily clogged and require regular maintenance. There is also continuous dynamic contact between the carton flaps and a"wear bar"that holds the flaps against the glue guns and at a specific distance from the glue orifices. This requires periodic adjustments and eventual replacement of the wear bar and doctor blade assembly.

Italian Patent BO 94A 000,044 assigned to Senzani is directed to an apparatus for tightly securing the closing tabs of the ends of cases or boxes, by means of lines of glue delivered partly onto the tabs, with orientation transverse to the forward moving direction of the boxes. The apparatus described in this patent application suffers from a number of drawbacks. A primary drawback is the fact that the apparatus is driven by the same drive that powers the boxing machine. The boxing machine may not have sufficient power to drive such an apparatus. This patent teaches no way to phase the application of the glue onto the boxes other than by tying the movement of the glue application apparatus to the boxing machine.

European Patent Application EP 1 069 045 Al assigned to Senzani is directed to an apparatus for supplying adhesive to dispensing heads. The apparatus described in this patent application also suffers from a number of drawbacks. A primary drawback is the complicated nature of the apparatus, and the potential for leakage of the adhesive from the flexible hose connection and rotary hydraulic coupling shown therein.

U. S. Patent 5,094, 398 issued to Jeter, et al. (assigned to Nordson Corporation) is directed to an apparatus for adjusting the relative position of two or more material dispensers.

Thus, there is a need to provide improved methods and apparatus for applying glue to boxes.

SUMMARY OF THE INVENTION The present invention relates to a method and apparatus for applying glue to boxes, and more particularly to a method and apparatus that is used for applying glue to boxes during a process of sealing the flaps of boxes.

There are numerous, non-limiting embodiments of the invention. In one embodiment, the apparatus may comprise an independently powered, stand alone apparatus for applying glue to the flaps of boxes that is associated with a box-making assembly line or box conveying line. The apparatus may be driven independently from the mechanism that drives the box-making assembly line or conveying line, yet phased to apply adhesive on the proper locations on the box flaps. The apparatus may comprise a moving mechanism that applies glue to the boxes as it moves at an angle to the direction the boxes are moving.

In the foregoing, or other embodiments, the method may comprise applying a first line of glue to the trailing flap of a first box and a second line of glue to the leading flap of the second box.

The apparatus may have a non-limiting number of other features that comprise inventions in their own right. Such features include, but are not limited to an improved assembly for conveying glue to the glue guns.

BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes with claims particularly pointing out and distinctly claiming the invention, it is believed that the present invention will be better understood from the following description taken in conjunction with the accompanying drawings in which: Fig. 1 is a partially fragmented side view of one non-limiting embodiment of a portion of an assembly line for folding and sealing the flaps of boxes.

Fig. 2 is a plan view of a portion of the assembly line shown in Fig. 1.

Fig. 3 is a top view of one non-limiting embodiment of the apparatus for applying glue to the boxes.

Fig. 4 is a side view of the apparatus shown in Fig. 3.

Fig. 5 is an end view of the apparatus shown in Fig. 3.

Fig. 6 is a schematic plan view showing the how the glue pattern is formed on a pair of boxes.

Fig. 7 is a cross-sectional view of a line of adhesive taken along line 7-7 of Fig. 6 that shows an example of the flattened cross-sectional shape that some lines of adhesive may have.

Fig. 8 is a cross-sectional view taken from the same perspective as Fig. 7, that shows an example of a beaded cross-sectional shape that other lines of adhesive may have.

Fig. 9 is a schematic fragmentary side view of a box showing a final step in the folding and sealing of its flaps.

Fig. 10 is a schematic perspective view of a portion of the platform and rail system of the embodiment of the adhesive application apparatus shown in Figs. 3-5.

Fig. 11 is a side view of the assembly that supplies glue to the glue guns.

Fig. 12 is a plan view that shows the operating sequence of the apparatus on two boxes.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for applying glue to boxes, and more particularly to a method and apparatus that is used for applying glue to boxes during a process of sealing the flaps of boxes.

There are numerous, non-limiting embodiments of the invention. Several non-limiting embodiments are described herein, as are several components of the apparatus, each of which may constitute an invention either in its own right or together with other components. All embodiments, even if they are only described as being"embodiments"of the invention, are intended to be non-limiting (that is, there may be other embodiments in addition to these), unless they are expressly described herein as limiting the scope of the invention.

The terms"boxes", "cartons"and"cases", as used herein, can all be considered to be synonymous for the purpose of the present invention. The terms"glue"and"adhesive", as used herein, will also be considered to be synonymous.

One non-limiting embodiment of an apparatus for carrying out the present invention is shown in Figs. 1-5. Figs. 1 and 2 show one non-limiting embodiment of a portion of an assembly line 10 for folding and sealing the flaps of boxes. The assembly line 10 for folding and sealing the flaps of boxes shown in Figs. 1 and 2 comprises a conveyor, which may be in the form of a continuous belt 12. The assembly line 10 may be used for not only folding and sealing the flaps of boxes, but also for filling the boxes with product (s). Therefore, the assembly line 10 for folding and sealing the flaps of boxes may be alternatively referred to as box-making machine or a carton-filling machine 10.

The box-making machine 10 may comprise a drive mechanism 14 and a filling station 16.

The endless belt 12 travels around pulleys designated generally by reference number 18, and separately as pulley 18A and pulley 18B. The boxes 24 are traveling in the direction of the arrow designated"MD" (or in the"machine direction") in the box-making machine 10. The boxes can be provided to the box-making machine 10 in a"knocked down flat"condition. The box-making machine 10 can open the knocked down flat boxes into rectangular shapes.

As shown in Fig. 2, the box-making machine 10 may comprise more than one (e. g. , two) adhesive application apparatuses 20. One apparatus can be used for sealing the flaps on the bottom of the box, and the other apparatus can be used for sealing the flaps on the top of the box.

The two apparatuses 20 can be similar, or opposite hand copies of each other. An opposite hand copy of one of the apparatuses 20 can be inverted relative to the other to apply adhesive on the other side of the box. As shown in Fig. 2, the box-making machine can be arranged in the form of a conveyor that forms a loop when viewed from above, and one of the apparatuses can be located on one side of the loop, and the other apparatus can be located on the other side of the loop. In the embodiment shown in the drawings, after one side of the boxes are sealed by the adhesive application apparatus 20 shown in the lower portion of Fig. 2, the boxes 24 travel to the filling station 16 where the product (s) are placed in the boxes. The boxes then move to the adhesive application apparatus 20 shown in the upper portion of Fig. 2 where the flaps on the other side of the boxes are folded as sealed.

As shown in greater detail in Fig. 3, the adhesive application apparatus (or simply "apparatus") 20 comprises one or more glue guns designated generally by reference number 22 that apply glue to boxes that are designated generally by reference number 24. In this embodiment, the glue guns apply glue to at least portions of the flaps 26 of the boxes 24. Fig. 3 shows that the boxes 24 are traveling in the direction of the arrow designated"MD"in the box- making machine 10 that folds the flaps 26 and closes at least a portion of the boxes 24.

In the embodiment shown in Figs. 3-5, there are three glue guns, 22A, 22B, and 22C. As shown in Fig. 5, the glue guns 22 have nozzles 30, which have orifices 32. The glue guns 22 may be of any suitable type. However, in preferred embodiments, the glue guns 22 are of the"non- contact"type. In other words, the glue guns 22 never make contact with the surface to which the glue is applied, such as the carton flaps 26. One example of such a glue gun is referred to as the E350 glue module available from Nordson Corporation of Duluth, Ga. , USA. In the apparatus described herein, the glue guns 22 can be used in a truly non-contact manner, with the nozzles 30 of the glue guns 22 spaced between as much as 1/4 inch to 3/8 inch (6.4 mm to 9.5 mm) from the portions of the box flaps 26 to which the adhesive is applied. (Of course, in other less desirable embodiments, contact glue guns can be used. ) The glue guns 22 have an internal valve that can be operated mechanically, electrically, or pneumatically.

The boxes 24 and one example of the pattern of glue that can be applied to the flaps 26 thereof, are shown schematically in Fig. 6. As shown in Fig. 6, in this embodiment, the apparatus applies glue to portions of the flaps of two boxes, box 24A and box 24B simultaneously.

However, the apparatus and method described herein is not limited to simultaneous application.

(It should also be understood that this is a non-limiting example, and in other embodiments, the apparatus 20 may apply glue to the flaps of a single box, rather than to portions of the flaps of two boxes during the process. ) Box 24A will be referred to herein as a first box, and box 24B will be referred to as a second box. Each of the boxes 24A and 24B has a leading side 34, a trailing side 36, and two lateral sides 38 and 40.

The boxes 24 each have flaps 26 comprising a leading flap 42 and a trailing flap 44 (which form a first pair of flaps that may be referred to as the"minor flaps"in this embodiment), located on opposite sides of the box adjacent the leading and trailing sides of the box, respectively, and a second pair of flaps, comprising flaps 46 and 48. Each flap in the second pair of flaps (which in this embodiment, may be referred to as the"major flaps") is located adjacent to one of the lateral sides 38 and 40 of the box on opposite sides of the box. The boxes 24A and 24B can optionally be separated by a spacer, such as a spacing block 49. The spacing block 49 has a centerline, CL.

In the embodiment shown in Fig. 6, the adhesive is applied in the general pattern of an upper case letter"U"on each box. This is shown on box 24B. The adhesive pattern comprises a leading line of adhesive 50, a trailing line of adhesive 52, and a third line of adhesive 54. The leading line of adhesive 50, the trailing line of adhesive 52, and the third line of adhesive 54 may be connected, such as through the third line of adhesive 54 as shown in Fig. 6. In other embodiments, they need not connect. In the embodiment shown in Fig. 6, the lines of adhesive may be rectilinear. In other embodiments, the lines of adhesive may be rectilinear, curvilinear, or have sections that are both rectilinear and curvilinear. The lines of adhesive can be continuous, intermittent, or they can have some portions that are continuous and some portions that are intermittent. The adhesive need not even be in the form of lines. For example, a suitable adhesive pattern can be formed of a plurality of spots of adhesive such as by turning the glue guns on and off. In these or other embodiments, there can be more than one line or pattern of adhesive on each flap. This might be useful, for example if the boxes have handles, and a region of adhesive needs to be applied on each side of the handle. More than one line or pattern of adhesive can be formed by multiple glue guns or by glue guns with a split nozzle tip.

In the embodiment shown in Fig. 6, the leading and trailing lines of adhesive 50 and 52 have gaps 56 therein. Gaps 56 can be left for any suitable reason, such as to avoid having the adhesive come into contact with portions of the equipment that hold the flaps folded. In this embodiment, a gap is left for rail 64 that keeps the first pair of flaps folded down so that glue can be applied thereto. As shown in Fig. 3, a second rail 65 holds the second pair of flaps in a folded down configuration as well.

The lines of adhesive 50,52, and 54 can be of any width and any cross-sectional configuration. Non-limiting examples of possible cross-sectional configurations of lines of adhesive are shown in Figs. 7 and 8, with the adhesive being designated by reference number 58.

Fig. 7 shows an example of the flattened cross-sectional shape that some lines of adhesive may have. Fig. 8 shows an example of a raised or beaded cross-sectional shape that other lines of adhesive may have. The apparatus 20 may provide the lines of adhesive in either cross-sectional shape. However, in some embodiments, the beaded cross-sectional shape shown in Fig. 8 is preferred. Many prior apparatuses have been unable to form lines of adhesive that are oriented perpendicular to the machine direction (such as leading and trailing lines of adhesive 50 and 52) that have a beaded cross-section due to the fact that these apparatuses used contact-type glue guns or other types of applicators that needed to wipe or smear the adhesive on the box flaps when lines of adhesive are applied perpendicular to the machine direction.

The beaded cross-sectional configuration of the adhesive shown in Fig. 8 may be preferred for sealing the portion of the box shown in Fig. 9. There are several reasons for this.

When the lines of adhesive have a raised cross-section (as opposed to a flattened cross-sectional configuration, such as that shown in Fig. 7), the adhesive can function more like caulking in filling gaps 60 such as those formed when the box flaps 26 are folded as shown in Fig. 9. This can provide the sealed box with better sift-proof and infestation proof characteristics.

There are two periods of time that are of interest in sealing boxes with heated adhesives.

The first period of time is the period that the adhesive remains sufficiently molten that it is capable of forming a bond with other portions of the box. This may be referred to herein as the "molten time"or"open time". After the molten time, the adhesive will harden and the flap with the adhesive thereon will not be able to form a bond with other portions of the box. The second period of time is the period that the adhesive requires to bond with other portions of the box.

This may be referred to herein as the"tack time"or the"green seal time". Once the adhesive is applied to the flap and the flap is brought into contact with the other portion of the box to which it is intended to be bonded, it is desirable that the adhesive set or"freeze"as quickly as possible.

If pressure is used to effect the bond, the faster the adhesive sets, the shorter the amount of time pressure is required to be applied to ensure that a seal is formed.

If the adhesive is heated, the raised cross-section of the adhesive also allows the beaded line of adhesive to retain heat better than a flattened line of adhesive due to the smaller surface area of exposed adhesive relative to the amount of adhesive in the line of adhesive. This allows the beaded line of adhesive to continue to remain taclcy, maintaining or increasing the molten time for the same, or a lesser amount of adhesive. Lesser amounts of adhesive can also reduce the tack time, and the length of time and/or amount of pressure that is required to be applied on the flaps 46 and 48 to keep the flaps folded until the adhesive"sets". The use of the raised bead of adhesive may allow the speed of the box-making line to be increased due to the shorter tack time. If desired, the speed of the box-making line may even be decreased because the adhesive retains its heat longer, and the flaps do not have to be folded as quickly after a heated adhesive is applied. Thus, the method and apparatus described herein may reduce the amount of adhesive required, and provide greater flexiblility in the operation of the box-making machine.

The use of a raised bead of adhesive may also permit less expensive, lower temperature adhesives to be used since the heat will not dissipate from the raised line of adhesive as rapidly as it does from the flattened line of adhesive. In other embodiments, "cold"or unheated types of adhesive can be used. The use of the non-contact glue guns can also result in a potentially substantial savings in the amount of adhesive required, particularly with respect to prior types of apparatuses that extrude and wipe the adhesive. It has been found during the operation of such prior machines that the contact nature of the adhesive applicators, and the wear on the same, makes it continuously necessary to increase the amount of adhesive used in such apparatuses over time in order to achieve a good seal. The use of non-contact glue guns reduces or eliminates this problem.

The apparatus 20, and its operation will now be loolced at in greater detail. In the embodiment of the apparatus 20 shown in Fig. 3, one or more of the glue guns 22, such as stationary glue gun 22A, may be mounted in fixed positions and does not move during the glue application process. The stationary gun 22A is located so as to place a long continuous bead of glue onto the flaps that are parallel to the direction of carton travel and (or the"machine direction") at specific locations on the flaps. This line of glue forms the third line of adhesive 54 which forms the"connecting bars"between the two legs of the"U"pattern shown in Fig. 6. In a preferred embodiment, this line of glue has a beaded cross-sectional configuration such as that shown in Fig. 8.

The other two glue guns, 22B and 22C, are dynamic (movable) and are used to create the leading and trailing lines of adhesive, 50 and 52, which form the two legs of the glue patterns that are perpendicular to the direction of carton travel. These guns 22B and 22C are mounted on a platform 62 that slides back and forth in the direction of the double-headed arrow S on a bearing rail 63. The entire assembly is shown in greater detail in Fig. 10. As shown in Fig. 10, the assembly comprising a beam 61, the bearing rail 63, and a linear bearing 67 that slides in the direction of the arrow S. The platform 62 is mounted on the linear bearing 67. As shown in Fig.

3, the bearing rail 63 is mounted in a position opposite the carton flaps and at an angle to the machine direction. In the embodiment shown in Fig. 3, the angle, A, is about 60°. In other embodiments, the angle A can be any suitable angle, including angles greater than about 45°.

In the embodiment shown in the drawings, hot glue is supplied to the glue guns 22 through an glue conveying assembly 80 that has a unique configuration. As shown in Fig. 11, the glue conveying assembly 80 comprises a glue supply 81 that supplies glue through a conduit, preferably a flexible conduit such as a flexible hose 82, that can be formed in the configuration of an arch. The hose 82 can be supported by a flexible support 84 that can be made of plastic or other suitable material. If desired, the hose 82 can be in more than one section. The hose 82 may be a heated hose, and can be obtained from Nordson Corporation. The hose 82 can be held onto the support 84 in any suitable manner, including by several springs 86. The hose 82 is preferably arched so that it moves from a first position in which the radius of the apex of the arch is smaller to a flattened second position in which the radius of the apex of the arch is larger. The arched configuration may ensure that there are no sharp bends in the hose 82, and may help eliminate or reduce any movements that would rub or wear the hose 82.

The hose 82 can be formed into an arch that is in any suitable orientation. In the embodiment shown in the drawings, the hose 82 is arched over the path of movement by the dynamic glue guns 22B and 22C. In other embodiments, the orientation of the arch of the hose 82 can be at any suitable angle relative to the path of movement of the glue guns. In other embodiments, the arch can be inverted, or in less preferred embodiments, oriented in a sideways orientation. The arched configuration of the hose 82 may provide a more simple and reliable mechanism than the assemblies used to supply glue in other devices, such as the rotary hydraulic coupling shown in European Patent application EP 1 069 045 Al.

In the embodiment shown, the platform 62 is connected to a crank arm 66 by means of a connecting rod 68. The crank arm 66 is mounted to the shaft 70 of a gearbox 72. The gearbox 72 can be driven by any suitable type of apparatus that can be used to generate motion, or more particularly, in this embodiment, since a crank arm is used, radial motion. The apparatus in this embodiment comprises a phasing mechanism that phases the application of glue onto the box flap. Preferably the phasing mechanism is a servo-controlled apparatus or device (that is, a feedback control system). In the embodiment shown, a servomotor 74 drives the gearbox 72, and because of the radial motion, the servomotor may constantly changes its speed. Servomotors have been used in robots previously. A suitable servomotor for the apparatus shown in the drawings is the Allen-Bradley H-4050-P-HOOAA servomotor available from Rockwell Automation of Milwaukee, Wisconsin, USA.

The movement of the glue guns 22B and 22C is, thus, not powered by the drive mechanism that drives the box-making machine 10. This allows the apparatus 20 to be inserted into existing box-making machines as a stand-alone unit operation which does not need to be tied into the the same drive that powers the box-making machine. In other embodiments, the platform 62 can be driven by an apparatus that generates a linear motion. Suitable apparatuses of this type include, but are not limited to: a linear motor, a linear actuator, or a servomotor. In other embodiments, the crank arm 66 can be replaced by a cam so the motor can run at a more constant speed that may be more closely tied to the speed of the box-making machine 10.

Rotation of the crank arm 66 in the direction of the arrows by the servomotor 74 causes the two glue guns 22B and 22C to move back and forth on the rail 63 at an angle over the carton path. The glue guns 22B and 22C move between the position shown in Fig. 3 and the position shown in dashed lines in Fig. 3. As shown in Fig. 12, the movement of the glue guns 22B and 22C occurs in such a way that moves the gun nozzles along a path that stays parallel to the leading and trailing edges of the moving cartons.

In the embodiment shown, the movement of the glue guns 22B and 22C is kept in phase with the movement of the boxes in the box-making machine in the following manner. The apparatus 20 is provided with a box or carton position-indicating device. In this embodiment, the carton position-indicating device is a position feedback device. A suitable position feedback device is an electromechanical device comprising an encoder (or"resolver") 78. A suitable encoder 78 for the apparatus shown in the drawings is the XH25D-SS-12, 500-T5-ABZC-4469- SM18 encoder available from BEI Encoder Division Sensors and Systems Company of 7230 Hollister Avenue, Goleta, California 93117-2891, USA. As shown in Fig. 1, the encoder 78 is driven by the belt 12 and pulley 18B that is opposite the pulley 18A which is being driven by the drive 14 of the box-making machine 10. In other embodiments, the encoder 78 can be located in any other suitable location and driven by any other component, such as other components of the box-making machine 10. The encoder 78 (or other carton position-indicating device) is in electrical or electronic communication with the servomotor 74 such as through a wire, or otherwise.

In this embodiment, the encoder 78 makes one revolution for each"pitch length"on the box-making machine 10. The pitch length can be set at the distance between any established point in the box-making process to the next occurrence of that point. In this embodiment, the pitch length is set as the distance between the centerline, CL, in Fig. 6, of each successive spacer 49 between adjacent boxes 24. The encoder 78 can communicate the location of the boxes 24 to the servomotor 74. This communication allows the servomotor 74 to move the glue guns 22B and 22C at the proper time to apply glue to the desired portions of the leading and trailing flaps 42 and 44. In other embodiments, types of devices can be used other than encoders that allow the follower (apparatus 20) to be phased in sync with the box-making machine 10 (or master machine). Such other devices may include, but are not limited to DC motors, computerized controllers, and the like.

The two guns 22B and 22C are positioned so that while one moving nozzle orifice places a line of glue 50 along the trailing flap 44 of a first carton, the second moving gun is placing a line of glue 52 along the leading flap 42 of the second carton. Two consecutive revolutions of the crank arm 66 are required to apply both the leading and the trailing glue lines 50 and 52 on a single carton. The apparatus may further include optical devices to ensure that a carton is present when the adhesive is to be applied from the glue guns 22.

The possible variations of the embodiment shown in the drawings, include but are not limited to the following. In other variations of the embodiment, the two dynamic glue guns 22B and 22C can be arranged so that a single pass of the gun platform 62 will apply glue to the leading and trailing flaps of the same carton. In other variations or embodiments, other types of linear bearings and rails, or alternatives thereto, can be used.

The apparatus for sealing boxes may provide numerous advantages including, but not limited to: (a) improved quality and consistency in flap bonding; (b) less glue required which results in significant packaging cost savings; (c) significant maintenance savings due to the simpler and more reliable design; and (d) less machine down time, improving the box-making line efficiency. However, it should be understood that the claimed invention may provide these advantages, but is not required to provide any of these advantages, or any of the other potential advantages described throughout this specification.

Other advantages include the ability to use"off the shelf'glue guns which are much less expensive than the arrangement of the custom made and carton specific glue guns and doctor blades described in the Background of the Invention. The initial set up of the apparatus is easier to achieve and maintain for the following reasons: 1) the carton flaps never make direct contact with any of the glue gun orifices, therefore, no wear occurs on the external extremeties of the glue guns; and 2) a gap exists between the gun nozzle orifices and the carton flaps. The size of the gap can vary to some degree without having significant impact on the quality of the glue bond achieved.

In addition, the non-contact nature of the glue guns, and a reduction in the duration and/or amount of pressure that may be needed to seal the flaps may allow the amount of equipment that is generally used to apply pressure perpendicular to the flaps to seal the flaps to be reduced or eliminated. When the amount of this equipment is reduced or eliminated, this opens up space on the box-making line. The fact that a certain amount of this equipment was previously required would place constraints on the size of boxes that could be sealed on the box- making machine. Since the amount of this equipment can be reduced and/or eliminated, there can be more flexibility in the size of the boxes that can be run on existing box-making machines. In the case of new box-making machines, the design of these machines is less constrained by the requirements of the glue system.

The disclosure of all patents, patent applications (and any patents which issue thereon, as well as any corresponding published foreign patent applications), and publications mentioned throughout this description are hereby incorporated by reference herein. It is expressly not admitted, however, that any of the documents incorporated by reference herein teach or disclose the present invention.

While particular embodiments of the subject invention have been described, it will be obvious to those skilled in the art that various changes and modifications of the subject invention can be made without departing from the spirit and scope of the invention. In addition, while the present invention has been described in connection with certain embodiments thereof, it is to be undersood that this is by way of illustration and not by way of limitation and the scope of the invention is defined solely by the appended claims which should be construed as broadly as the prior art will permit.