Claims:1. An interlock defeat for an electrical equipment enclosure that is mounted on a structural pillar using a fixed pin (6), said interlock defeat comprising:
a first assembly having a defeat screw (1), a spring loaded bracket (2), and a rotating lever (3) that is mounted on a door (7) hingedly attached to a first side of the electrical equipment enclosure; and
a second assembly having a bracket (4) and a locking lever (5) mounted on a second side of the electrical equipment enclosure adjacent to the first side when the door is closed, wherein an interlock between the locking lever (5) and the rotating lever (3) is defeated by a rotation of the defeat screw (1) that enables the interlock between the locking lever (5) and the rotating lever (3) to unlock for allowing the door to be opened while current is flowing through an electrical equipment therein.

2. The interlock defeat as claimed in claim 1, wherein rotation of the defeat screw (1) enables rotates the spring loaded bracket (2) and the rotating lever (3) to defeat the interlock between the locking lever (5) and the rotating lever (3).

3. The interlock defeat as claimed in claim 1, wherein the rotating lever (3) rides over the locking lever (5), while closing the door, to enable the interlock between the locking lever (5) and the rotating lever (3).

4. The interlock defeat as claimed in claim 1, wherein the interlock between the locking lever (5) and the rotating lever (3) locks for restricting unauthorized access to an interior of the electrical equipment enclosure.

5. The interlock defeat as claimed in claim 1, wherein the interlock defeat operates in a service position and a test position of the electrical equipment residing in the electrical equipment enclosure.

6. The interlock defeat as claimed in claim 5, wherein the locking lever, in the test position, is adapted to turn horizontal due to position of the fixed pin, to enable the interlock between the locking lever (5) and the rotating lever (3).

7. The interlock defeat as claimed in claim 5, wherein the locking lever, in the service position, is adapted to turn horizontal due to position of the fixed pin, to enable the interlock between the locking lever (5) and the rotating lever (3).

8. The interlock defeat as claimed in claim 1, wherein the electrical equipment is a switchboard.

9. The interlock defeat as claimed in claim 1, wherein the electrical equipment is an air circuit breaker (ACB).

10. An electrical equipment comprising an interlock defeat as claimed in claim 1.
, Description:TECHNICAL FIELD
[0001] The present disclosure relates to mechanical door safety interlocks, and more specifically relates to, a door defeat interlock (hereinafter interchangeably referred as “interlock defeat”) for opening door in service and test position of withdrawable modules in switchboards.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] For safety reasons, high-power electrical or electronic devices which contain voltages lethal to people are housed in enclosures that have locking doors. The enclosures are either made from electrically insulating, fireproof material, or they are made of metal and are electrically connected to earth (or safety) ground with large conductors so that if anything inside the enclosure breaks, arcs, explodes, or otherwise malfunctions, the lethal voltage is contained within the enclosure. The enclosure prevents any significant voltage from escaping to the exterior of the enclosure, irrespective of what occurs inside the enclosure.
[0004] In such enclosures that contain high-power electrical or electronic devices and/or switchgear, there is often a circuit breaker (which is in essence a disconnect switch) that is placed in series with the incoming electrical power line. This circuit breaker is coupled to a handle that is located on the outside of the enclosure, which handle may be manipulated to operate the circuit breaker located inside the enclosure to turn the electrical power in the enclosure on or off. To protect people from the hazardous voltage that is present inside the enclosure, the circuit breaker is often mechanically interlocked with the enclosure door so that the door cannot be opened when the handle is in the on position.
[0005] This mechanical interlocking function is typically performed by an interlock mechanism that is mechanically linked to a circuit breaker that is mounted inside the enclosure. One common type of circuit breaker is a rotary circuit breaker that is actuated by a rotating shaft operated by a handle located on the outside of the enclosure (typically on a bracket that is accessible through an opening located in the door of the enclosure). The handle is rotated between ON and OFF positions to operate the rotary circuit breaker. Rotation of the handle from the OFF position to the ON position actuates the interlock mechanism to cause it to lock the enclosure door closed, and rotation of the handle from the ON position to the OFF position allows the enclosure door to open. The interlock switch should also prevent the power switch from moving from the OFF position to the ON position while the enclosure door is open.
[0006] Efforts have been made in related art to address above stated problem by using door safety interlocks. An example of such interlocking mechanism is recited in a United States Patent 7420133B2, entitled “Door interlock for rotary actuated circuit breaker”. The patent discloses a simple, mechanical rotary circuit breaker door safety interlock for installation and use in an enclosure having a hinged door to operate a rotary circuit breaker that is actuated by rotation of a shaft that is operated by a handle located on and accessible from the outside of the enclosure with the hinged door closed. In this patent, the purpose of proposed interlock is to ensure that as long as the switch is ON, the door should not be opened. Once the switch is turned OFF, the door can be opened as the lever on the door gets relieved from the locking lever of the breaker. However, in the conventional door safety interlocks, there is no defeat provided for opening the door when the interlock is in active state. Further, in the conventional door defeat interlock, the interlock is not re-lockable while closing the door. The screw has to be kept rotated with a tool with one hand and door has to be closed with other hand. As per requirement of IEC 61439 standard, any defeat interlock if provided needs to be self-restoring. This condition is not fulfilled in the conventional door defeat interlock.
[0007] Whereas there is certainly nothing wrong with existing techniques, nonetheless, there still exists a need to provide an efficient, effective, reliable, improved a door defeat interlock for opening door in service and test position of withdrawable modules in switchboards. Further, the proposed invention provides a defeat mechanism for door opening in test and service position for withdrawable modules in switchboard. Furthermore, the interlock ensures that the door is opened by intentionally defeating the interlock ensuring safety in closed door condition.
[0008] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0009] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about”. Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[00010] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[00011] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[00012] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

SUMMARY
[00013] The present disclosure relates to mechanical door safety interlocks, and more specifically relates to, a door defeat interlock for opening door in service and test position of withdrawable modules in switchboards.
[00014] Accordingly, an aspect of the present disclosure relates to an interlock defeat for an electrical equipment enclosure that is mounted on a structural pillar using a fixed pin. The interlock defeat can include a first assembly and a second assembly. The first assembly can have a defeat screw, a spring loaded bracket, and a rotating lever that is mounted on a door hingedly attached to a first side of the electrical equipment enclosure. The second assembly can have a bracket and a locking lever mounted on a second side of the electrical equipment enclosure adjacent to the first side when the door is closed. An interlock between the locking lever and the rotating lever can be defeated by a rotation of the defeat screw that enables the interlock between the locking lever and the rotating lever to unlock for allowing the door to be opened while current is flowing through electrical equipment.
[00015] In an aspect, rotation of the defeat screw rotates the spring loaded bracket and the rotating lever to defeat the interlock between the locking lever and the rotating lever.
[00016] In an aspect, the rotating lever rides over the locking lever, while closing the door, to enable the interlock between the locking lever and the rotating lever.
[00017] In an aspect, the interlock between the locking lever and the rotating lever locks for restricting unauthorized access to an interior of the electrical equipment enclosure.
[00018] In an aspect, the interlock defeat operates in a service position and a test position of the electrical equipment residing in the electrical equipment enclosure.
[00019] In an aspect, the locking lever, in the test position can be adapted to turn horizontal due to position of the fixed pin, to enable the interlock between the locking lever and the rotating lever.
[00020] In an aspect, the locking lever, in the service position, can be adapted to turn horizontal due to position of the fixed pin, to enable the interlock between the locking lever and the rotating lever.
[00021] In an aspect, the electrical equipment can be a switchboard.
[00022] In an aspect, the electrical equipment is an air circuit breaker (ACB).
[00023] In an aspect, electrical equipment comprising an interlock defeat.
[00024] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[00025] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:
[00026] FIG. 1 illustrates a door defeat interlock and parts of door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00027] FIG. 2 illustrates a door defeat interlock and parts of door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00028] FIG. 3 illustrates a door defeat interlock and parts of door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00029] FIGs. 4-6 illustrate right handed side view of a door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00030] FIGs. 7-8 illustrate a front view of a door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00031] FIGs. 9-10 illustrate right handed side view of a door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION
[00032] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[00033] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[00034] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[00035] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
[00036] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[00037] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[00038] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[00039] Problems to be solved in the present invention are that: In conventional door defeat interlock is provided to open the door when the ACB is in test or service position. One part of interlock is on the door and other is on ACB. A fixed pin is provided on the structure. The interlock can be defeated by rotating the screw provided on the door. This releases the two brackets locked with each other and door can be opened. In conventional door defeat interlock, the interlock is not re-lockable while closing the door. The screw has to be kept rotated with a tool with one hand and door has to be closed with other hand. As per requirement of IEC 61439 standard, any defeat interlock if provided needs to be self-restoring. This condition is not fulfilled in the present invention. The present invention overcomes this drawback and fulfills the standard requirement.
[00040] Therefore there is a need of an efficient, effective, reliable, improved a door defeat interlock for opening door in service and test position of withdrawable modules in switchboards. Further, the proposed invention provides a defeat mechanism for door opening in test and service position for withdrawable modules in switchboard. Furthermore, the interlock ensures that the door is opened by intentionally defeating the interlock ensuring safety in closed door condition.
[00041] The present disclosure relates to mechanical door safety interlocks, and more specifically relates to, a door defeat interlock for opening door in service and test position of withdrawable modules in switchboards.
[00042] Accordingly, an aspect of the present disclosure relates to a door defeat interlock for opening door in service and test position of withdrawable modules. In present invention, a defeat screw and rotating lever can be provided on the door. The locking lever can be provided on the module. There is a fixed pin provided on the structure. When module is in isolated position, the locking lever is fallen down and not locked with the rotating lever. Thus, door can be opened without defeat in this position. When the module starts moving from isolated to test position, the locking lever starts getting lifted up since it rides on the fixed pin mounted on the structure. The locking lever is tangential to the fixed pin. When the module comes to test position, the lever becomes horizontal and locks the rotating lever.
[00043] In an aspect, the rotating lever can be connected to defeat screw through a spring loaded bracket.
[00044] In an aspect, the door can be opened only when the defeat screw is rotated in anticlockwise direction and the rotating lever clears the locking lever. The locking lever remains horizontal throughout the module travel from test to service and vice-a-versa. Thus, the interlocking can be achieved in test and service position. During the closure of the door in test and service position, the rotating lever rides over locking lever and gets locked with it when the door is closed completely.
[00045] In a panel board, module with SCPD, contactor, relay are provided for operation, control and protection of loads like motor, pumps, conveyors etc. The modules can be withdrawable type. For withdrawing the module, racking mechanism is provided to take module from one position to other. The mechanism can either be open door or closed door type. There are three positions of the module: Isolated, Test and Service. In closed door operation of the module, the door is closed in test and service position. There can be situations where it becomes necessary to open the door even when the module is in service position (e.g. taking thermal data) or in test position. Thus, to ensure that the authorized person opens the door, tool operated defeat is provided. This defeat has to be restorable while closing the door again.
[00046] In present product, door defeat interlock is provided to open the door when the ACB is in test or service position. One part of interlock is on the door and other is on ACB. A fixed pin is provided on the structure. The interlock can be defeated by rotating the screw provided on the door. This releases the two brackets locked with each other and door can be opened. Furthermore
[00047] FIG. 1 illustrates a door defeat interlock and parts of door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00048] In an embodiment, the door defeat interlock can be divided in 3 parts.
[00049] As shown in FIG. 1 shows the defeat screw (1), spring loaded bracket (2) and rotating lever (3) assembly mounted on the door.
[00050] FIG. 2 illustrates a door defeat interlock and parts of door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00051] As shown in FIG.2, the bracket (4) and locking lever (5) assembly can be mounted on the module side plate.
[00052] FIG. 3 illustrates a door defeat interlock and parts of door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00053] As shown in FIG.3, a fixed pin (6) can be mounted on structural pillar.
[00054] FIGs. 4-6 illustrate right handed side view of a door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00055] In an embodiment, when the module is in isolated position, the locking lever (5) is fallen down since there is no pin to ride on. Thus, even when the door (7) is closed, the locking lever (5) and rotating lever (3) cannot locked with each other as shown in FIG. 4 (RHS view of the module in isolated position). Thus, in isolated position, the door (7) can be opened without defeat.
[00056] In an embodiment, when the module moves to test position, the locking lever becomes horizontal as it gets guided by the fixed pin mounted on the door. Thus, the locking lever and rotating lever gets locked to each other in door closed condition as shown in FIG.5. FIG. 5 indicates test position in RHS view of the module. The door cannot be opened in this position.
[00057] In an embodiment, in service position, the locking lever remains horizontal and locked with rotating lever. The service position is shown in FIG.6.
[00058] As shown in FIG.6, locking lever (5) and rotating lever (3) can be locked with each other.
[00059] FIGs. 7-8 illustrate a front view of a door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00060] As shown in FIG. 7 and 8 shows the front view of the module. In FIG. 7, the rotating lever and locking lever can be locked with each other as highlighted. To defeat the interlock, the defeat screw has to be rotated, which in turn rotates the spring loaded bracket and rotating lever assembly. As shown in FIG. 8, the rotating lever clears the locking lever and door can be opened.
[00061] In an exemplary embodiment, while closing the door, the rotating lever rides over the locking lever. Once it crosses the locking lever, it falls down and gets locked. The relocking of interlock can be achieved.
[00062] FIGs. 9-10 illustrate right handed side view of a door defeat interlock, in accordance with an exemplary embodiment of the present disclosure.
[00063] As shown in FIG. 9 the RHS view of the module during the closure of the door when rotating lever is riding over the locking lever. As shown in FIG. 10, the rotating lever and locking lever can be locked to each other when door is completely closed.
[00064] In an exemplary embodiment, lifting of the locking lever and its locking with the rotating lever on the door can be achieved relative to the module position.
[00065] It may therefore be appreciated from the above detailed description of the exemplary embodiments of the door safety rotary circuit breaker interlock of the present invention that it represents both a simplification to and an improvement upon other interlock devices that have been known in the past. Aside from the handle and the actuation shaft which are used to turn the rotary circuit breaker on and off and the door hook mounted on the back side of the enclosure door, the door safety rotary circuit breaker interlock of the present invention has only one moving part, namely the latch plate. No complex linkages or springs are either used or required for the door safety rotary circuit breaker interlock to operate, since gravity provides all the force that is necessary to move the latch plate from its unlocked position to its locked position.
[00066] Although the foregoing description of the door safety rotary circuit breaker interlock of the present invention has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. It will be apparent to those having ordinary skill in the art that a number of changes, modifications, variations, or alterations to the invention as described herein may be made, none of which depart from the spirit or scope of the present invention. The particular embodiments and applications were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such changes, modifications, variations, and alterations should therefore be seen as being within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
[00067] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.
[00068] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C ….and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the appended claims.
[00069] While embodiments of the present disclosure have been illustrated and described, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the scope of the disclosure, as described in the claims.
[00070] In the description of the present specification, reference to the term "one embodiment," "an embodiments", "an example", "an instance", or "some examples" and the description is meant in connection with the embodiment or example described The particular feature, structure, material, or characteristic included in the present invention, at least one embodiment or example. In the present specification, the term of the above schematic representation is not necessarily for the same embodiment or example. Furthermore, the particular features structures, materials, or characteristics described in any one or more embodiments or examples in proper manner. Moreover, those skilled in the art can be described in the specification of different embodiments or examples are joined and combinations thereof.
[00071] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[00072] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[00073] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
[00074] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.