Patent Publication Number: US-8973502-B2

Title: Simultaneous nonelectric priming assembly and method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 12/982,658, filed Dec. 30, 2010, the disclosures of which are expressly incorporated by reference herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     The invention described herein includes contributions by one or more employees of the Department of the Navy made in performance of official duties and may be manufactured, used and licensed by or for the United States Government for any governmental purpose without payment of any royalties thereon. 
    
    
     BACKGROUND AND SUMMARY OF THE DISCLOSURE 
     The present disclosure relates to a priming assembly and a method for coupling a plurality of detonators to at least one explosive through a plurality of transmission lines. 
     To perform certain mining operations, excavation operations, drilling operations, demolition operations, and military operations, for example, an explosive may be placed at a blasting site. To ensure the safety of a user, the user may trigger and detonate the explosive from a location remote from the blasting site. 
     According to an illustrative embodiment of the present disclosure, a priming assembly is provided for coupling a plurality of detonators to at least one explosive through a plurality of transmission lines. The priming assembly includes a housing having an outer wall, the housing extending along a longitudinal axis from a first end to a second end. The housing defines a plurality of detonator receptacles that are configured to receive the plurality of detonators and a plurality of transmission line receptacles that are configured to receive the plurality of transmission lines, each of the plurality of transmission line receptacles being semi-circular in shape to retain the plurality of transmission lines and to position the plurality of transmission lines relative to the plurality of detonators in the plurality of detonator receptacles while exposing the plurality of transmission lines to the plurality of detonators in the plurality of detonator receptacles such that an explosive charge from at least one of the plurality of detonators is communicated to the plurality of transmission lines and to the at least one explosive. 
     According to another illustrative embodiment of the present disclosure, a priming assembly is provided that includes a plurality of detonators, at least one of the plurality of detonators being configured to generate an explosive charge, a plurality of transmission lines, at least one explosive, and a housing having a plurality of detonator receptacles that are sized to receive the plurality of detonators and a plurality of transmission line receptacles that are sized to receive the plurality of transmission lines, each of the plurality of transmission line receptacles being semi-circular in shape to retain the plurality of transmission lines and to position the plurality of transmission lines relative to the plurality of detonators in the plurality of detonator receptacles while exposing the plurality of transmission lines to the plurality of detonators in the plurality of detonator receptacles such that the explosive charge from the at least one detonator is communicated to the plurality of transmission lines and to the at least one explosive. 
     According to yet another illustrative embodiment of the present disclosure, a method is provided for coupling a first detonator and a second detonator to at least one explosive. The method includes the steps of: providing a housing that includes a first detonator receptacle, a second detonator receptacle, and a plurality of transmission line receptacles, the plurality of transmission line receptacles receiving a plurality of transmission lines; inserting the first detonator into the first detonator receptacle of the housing to communicate with the plurality of transmission lines; inserting the second detonator into the second detonator receptacle of the housing to communicate with the plurality of transmission lines; and coupling the plurality of transmission lines to the at least one explosive. 
     According to still yet another illustrative embodiment of the present disclosure, a method is provided for manufacturing a priming assembly for coupling a plurality of detonators to at least one explosive through a plurality of transmission lines. The method includes the steps of: forming a housing that includes an outer wall defining an interior of the housing, a plurality of detonator receptacles in the interior of the housing, and a plurality of transmission line receptacles in the interior of the housing, the plurality of detonator receptacles being sized to receive the plurality of detonators and the plurality of transmission line receptacles being sized to receive the plurality of transmission lines, at least one of the plurality of transmission line receptacles communicating with the plurality of detonator receptacles within the housing; and inserting the plurality of transmission lines into the plurality of transmission line receptacles in the housing, at least one of the plurality of transmission lines communicating with the plurality of detonator receptacles within the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a front, assembled perspective view of an illustrative embodiment priming assembly that includes a housing for coupling a plurality of detonators to at least one explosive through a plurality of transmission lines; 
         FIG. 2  is a front, exploded perspective view of the priming assembly of  FIG. 1 , also showing a booster material that is located within the housing; 
         FIG. 3  is a rear, exploded perspective view of the housing of  FIG. 3 ; 
         FIG. 4  is a cross-sectional view of the priming assembly of  FIG. 1 ; 
         FIG. 5  is a cross-sectional view of the priming assembly of  FIG. 4 , taken along line  5 - 5  of  FIG. 4 ; and 
         FIG. 6  is another cross-sectional view of the priming assembly of  FIG. 4 , taken along line  6 - 6  of  FIG. 4 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring to  FIG. 1 , a priming assembly  10  is provided that includes a housing  100  for coupling a plurality of detonators  20  to at least one explosive  60  through a plurality of nonelectric transmission lines  40 . Although only a single explosive  60  is shown in  FIG. 1 , it is within the scope of the present disclosure that priming assembly  10  may include a plurality of explosives  60 , with each explosive  60  being coupled to a corresponding transmission line  40 . 
     In use, a signal is sent to detonate or trigger both detonators  20 . If both detonators  20  detonate substantially simultaneously (i.e., within 0.000001 seconds of one another), explosive charges from both detonators  20  may pass simultaneously to the plurality of transmission lines  40  in housing  100 . Even if one detonator  20  should fail, the explosive charge from the functioning detonator  20  may still pass simultaneously to the plurality of transmission lines  40  in housing  100 . For example, if the detonators  20  do not detonate substantially simultaneously (i.e., within 0.000001 seconds of one another), the first detonator will consume the second detonator, but the explosive charge from the first, functioning detonator may still pass to the plurality of transmission lines  40  in housing  100 . The explosive charge from one or both detonators  20  is conveyed or transmitted along transmission lines  40  to explosives  60 , which may be located at a remote blasting site, causing explosives  60  to detonate. In this embodiment, housing  100  may enable multiple transmission lines  40 , and in turn multiple explosives  60 , to detonate substantially simultaneously (e.g., within microseconds of one another), even when one detonator  20  may fail. Advantageously, housing  100  may accomplish this task reliably, safely, under potentially adverse weather conditions, nonelectrically, and/or inexpensively. 
     If priming assembly  10  were to include a single detonator  20 , instead of the plurality of detonators  20  of  FIG. 1 , a dangerous condition may result if that single detonator  20  failed. For example, a user would need to use extreme care and caution when handling the failed detonator  20  to avoid an unwanted detonation of detonator  20  and/or explosive  60 . On the other hand, by providing priming assembly  10  with a plurality of detonators  20 , the likelihood that at least one of the plurality of detonators  20  will function properly increases. 
     The illustrative embodiment priming assembly  10  includes two (2) detonators  20   a ,  20   b , although the number of detonators  20  may vary. For example, it is within the scope of the present disclosure that priming assembly  10  may include three (3), four (4), or more detonators  20 . 
     Detonators  20   a ,  20   b , may also be referred to as “blasting caps.” As shown in  FIG. 2 , each detonator  20   a ,  20   b , includes a corresponding signal line  22   a ,  22   b , and casing  24   a ,  24   b . Casing  24   a ,  24   b , of each detonator  20   a ,  20   b , contains a relatively sensitive, primary explosive material (not shown), which is less stable, and therefore easier to ignite, than the secondary explosive material (not shown) contained in explosives  60 . Because detonators  20   a ,  20   b , may easily ignite, detonators  20   a ,  20   b , should be stored apart from explosives  60 . 
     The types of detonators  20   a ,  20   b , used with priming assembly  10  may vary. Suitable detonators  20   a ,  20   b , include, for example, non-electric caps, electric caps which are triggered by an electric current, and fuse caps which are triggered with a match or another heat source. An illustrative detonator  20  is the MK 17 Electric Blasting Cap which is triggered by an electric current. 
     The primary explosive material contained in detonators  20   a ,  20   b , may also vary. Suitable primary explosive materials for use in detonators  20   a ,  20   b , include, for example, pentaerythritol tetranitrate (PETN), cyclotrimethylenetrinitramine (RDX), mercury fulminate, lead azide, lead styphnate, tetryl, and diazodinitrophenol (DDNP). 
     Additionally, the illustrative embodiment priming assembly  10  includes ten (10) nonelectric transmission lines  40   a - 40   j , although the number of transmission lines  40  may vary. For example, it is within the scope of the present disclosure that priming assembly  10  may include two (2), three (3), four (4), five (5), six (6), seven (7), eight (8), nine (9), eleven (11), twelve (12), thirteen (13), fourteen (14), or more transmission lines  40 . In certain embodiments, the number of transmission lines  40  may vary based on the number of explosives  60  provided. 
     Transmission lines  40   a - 40   j  may be provided in the form of “detonating cords” or “detcords,” for example, that are produced in accordance with the cut-off characteristics of PER14000035C, paragraph 3.5.1.1.2. Transmission lines  40   a - 40   j  may also be provided in the form of “shocktubes.” Each transmission line  40   a - 40   j  may include a flexible, hollow tube that contains a secondary explosive material (not shown). The secondary explosive material in each transmission line  40   a - 40   j  may convey or transmit the explosive charges from one or both detonators  20   a ,  20   b , to explosives  60 , allowing transmission lines  40   a - 40   j  to act as high-speed fuses. 
     The type and quantity of the secondary explosive material contained in transmission lines  40   a - 40   j  may vary. In the case of “detonating cords,” a suitable secondary explosive material for use in transmission lines  40   a - 40   j  includes, for example, pentaerythritol tetranitrate (PETN). In the case of “shocktubes,” a suitable secondary explosive material for use in transmission lines  40   a - 40   j  includes, for example, a mixture of cyclotetramethylene-tetranitramine (HMX) and aluminum. Also, suitable transmission lines  40   a - 40   j  may contain 5 grains of explosive per foot, for example, although it is also within the scope of the present disclosure that transmission lines  40   a - 40   j  may contain 0.1 grains of explosive per foot, 2.5 grains of explosive per foot, 7.5 grains of explosive per foot, 10 grains of explosive per foot, or 50 grains of explosive per foot, for example. 
     The speed at which an explosive charge travels through each transmission line  40   a - 40   j  may be substantially consistent. For example, in the case of “detonating cords,” the explosive charge may consistently travel through each transmission line  40   a - 40   j  at a speed between about 6,000 m/s and 6,800 m/s, and in the case of “shocktubes”, the explosive charge may consistently travel through each transmission line  40   a - 40   j  at a speed of about 2,000 m/s. By providing transmission lines  40   a - 40   j  of different lengths, a user may detonate multiple explosives  60  at different, yet controlled, times. For example, the user may detonate multiple explosives  60  in a specific order to control the collapse of a building. By providing transmission lines  40   a - 40   j  of the same length, on the other hand, the user may detonate multiple explosives  60  substantially simultaneously. Alternatively, a user may control the timing of detonating multiple explosives  60  using suitable delay detonators. 
     As shown in  FIG. 2 , each transmission line  40   a - 40   j  includes a corresponding, optional seal  42   a - 42   j  coupled to one end (i.e., the end closest to housing  100 ) and a corresponding cartridge  44   a - 44   j  coupled to the other end (i.e., the end closest to explosives  60 ). In certain embodiments, such as when transmission lines  40   a - 40   j  are provided in the form of “detonating cords,” cartridges  44   a - 44   j  may be provided in the form of booster cartridges that contain a secondary explosive material (e.g., pentaerythritol tetranitrate (PETN)). In other embodiments, such as when transmission lines  40   a - 40   j  are provided in the form of “shocktubes,” cartridges  44   a - 44   j  may be provided in the form of nonelectric detonator cartridges that contain both a primary explosive material and a secondary explosive material. Each booster cartridge  44   a - 44   j  may act as a bridge between its corresponding transmission line  40   a - 40   j  and explosive  60 . As an alternative to seals  42   a - 42   j , it is also within the scope of the present disclosure that, on the end closest to housing  100 , each transmission line  40   a - 40   j  may include a second cartridge similar to cartridges  44   a - 44   j  to act as a bridge between detonators  20   a ,  20   b , and its corresponding transmission line  40   a - 40   j.    
     The illustrative embodiment priming assembly  10  further includes one or more explosives  60 . In certain embodiments, each transmission line  40  is coupled to its own individual explosive  60 . For example, because the illustrative embodiment priming assembly  10  of  FIG. 1  has ten (10) transmission lines  40   a - 40   j , ten (10) explosives  60  may be provided, with each transmission line  40   a - 40   j  being coupled to its own individual explosive  60  (although only a single explosive  60  is shown in  FIG. 1 ). In other embodiments, more than one transmission lines  40   a - 40   j  may be coupled to a single explosive  60 . 
     In use, explosives  60  may be placed at a blasting site. For example, explosives  60  may be placed at the site of an excavation operation, a drilling operation, a demolition operation, a military operation, or another suitable operation. Transmission lines  40   a - 40   j  span between detonators  20   a ,  20   b , and explosives  60 , allowing the user to safely trigger detonators  20   a ,  20   b , at a location remote from the blasting site. 
     As discussed above, each explosive  60  may contain a relatively stable, secondary explosive material (not shown). The secondary explosive material contained in explosives  60  may vary. Suitable secondary explosive materials for use in explosives  60  include, for example, cyclotrimethylenetrinitramine (RDX), cyclotetramethylene-tetranitramine (HMX), and trinitrotoluene (TNT). 
     Referring next to  FIGS. 2-4 , the illustrative housing  100  of priming assembly  10  is a multi-piece construct having first portion  102  that receives the plurality of detonators  20  and second portion  104  that receives the plurality of transmission lines  40 . However, it is also within the scope of the present disclosure that housing  100  may be a one-piece, unitary construct. 
     First portion  102  of housing  100  includes outer wall  103  and second portion  104  of housing  100  includes outer wall  105 . When assembled, as shown in  FIG. 4 , outer walls  103 ,  105 , of first and second portions  102 ,  104 , cooperate to define interior  101  of housing  100  that is at least partially hollow. Housing  100  extends along longitudinal axis  106  from input end  108  to output end  110 . 
     As shown in  FIG. 4 , first portion  102  of housing  100  defines recess  112  and second portion  104  of housing  100  includes rim  114  that is sized for receipt within recess  112 . In certain embodiments, first and second portions  102 ,  104 , of housing  100  may be coupled together with a suitable adhesive  116 , as shown in  FIG. 4 . In other embodiments, first and second portions  102 ,  104 , of housing  100  may be coupled together with a mechanical fastener, such as a screw (not shown) or a latch (not shown), for example. 
     Housing  100  of priming assembly  10  may be constructed of a consumable material, such as plastic or rubber, or another suitable material. For example, depending on the amount of fragmentation produced, housing  100  may be constructed of an acrylonitrile butadiene styrene (ABS) thermoplastic, Santoprene™ thermoplastic vulcanised (TPV) rubber, or another suitable material having a hardness of about 80 Durometer. Illustrative methods of manufacturing housing  100  include, for example, injection molding. 
     First portion  102  of housing  100  defines a plurality of channels or receptacles  120  for receiving and supporting the plurality of detonators  20  therein. In the illustrated embodiment of  FIG. 4 , for example, first portion  102  of housing  100  defines two (2) receptacles  120   a ,  120   b , for receiving and supporting detonators  20   a ,  20   b , respectively. However, it is within the scope of the present disclosure that first portion  102  of housing  100  may define more than two (2) receptacles  120  for receiving more than two (2) detonators  20 . 
     As shown in  FIG. 4 , receptacles  120   a ,  120   b , extend entirely through first portion  102  of housing  100  in a direction substantially parallel to one another and to longitudinal axis  106 . In other words, receptacles  120   a ,  120   b , extend from input ports  122   a ,  122   b , in input end  108  of housing  100  ( FIG. 2 ) toward second portion  104  of housing  100  ( FIG. 3 ). In this way, detonators  20   a ,  20   b , may be inserted into input ports  122   a ,  122   b , in input end  108  of housing  100 , through receptacles  120   a ,  120   b , in housing  100 , and toward second portion  104  of housing  100 . 
     To enable housing  100  to hold detonators  20  of various shapes and sizes, each receptacle  120   a ,  120   b , of housing  100  may include an array of radially inwardly extending, flexible fins  124   a ,  124   b . When smaller diameter detonators  20   a ,  20   b , are inserted into housing  100 , fins  124   a ,  124   b , may extend radially into each receptacle  120   a ,  120   b , to grab and hold the respective detonator  20   a ,  20   b . On the other hand, when larger diameter detonators  20   a ,  20   b , are inserted into housing  100 , fins  124   a ,  124   b , may flex to increase the effective internal diameter of each receptacle  120   a ,  120   b , thereby making room for the insertion of each detonator  20   a ,  20   b , without causing an undue increase in the amount of force applied to each detonator  20   a ,  20   b . In certain embodiments, fins  124   a ,  124   b , of each receptacle  120   a ,  120   b , may be configured to grab and hold detonators having diameters between at least 0.210 inches and 0.300 inches. To enable flexion of fins  124   a ,  124   b , relative to housing  100 , fins  124   a ,  124   b , may be constructed of a material that is more flexible than housing  100 . For example, fins  124   a ,  124   b , may be constructed of thermoplastic vulcanised (TPV) rubber having a hardness of about 60 Durometer. It is also within the scope of the present disclosure that receptacles  120   a ,  120   b , of housing  100  may include threaded inserts and priming adapters (not shown) to receive and hold detonators  20   a ,  20   b.    
     Second portion  104  of housing  100  defines a plurality of channels or receptacles  140  for receiving and supporting the plurality of transmission lines  40  therein and for positioning transmission lines  40  relative to detonators  20 . In the illustrated embodiment of  FIG. 4 , for example, second portion  104  of housing  100  defines ten (10) receptacles  140   a - 140   j  for receiving and supporting transmission lines  40   a - 40   j , respectively. However, it is within the scope of the present disclosure that second portion  104  of housing  100  may define fewer than ten (10) receptacles  140  for receiving fewer than ten (10) transmission lines  40 , or that second portion  104  of housing  100  may define more than ten (10) receptacles  140  for receiving more than ten (10) transmission lines  40 . 
     As shown in  FIG. 4 , receptacles  140   a - 140   j  extend entirely through second portion  104  of housing  100  in a direction substantially parallel to one another and to longitudinal axis  106 . In other words, receptacles  140   a - 140   j  extend from first portion  102  of housing  100  ( FIG. 2 ) toward output ports  142   a - 142   j  in output end  110  of housing  100  ( FIG. 3 ). In certain embodiments, and as shown in  FIG. 4 , seals  42   a - 42   j  of transmission lines  40   a - 40   j  may be sized larger than receptacles  140   a - 140   j  to prevent transmission lines  40   a - 40   j  from withdrawing from housing  100  through output ports  142   a - 142   j  in output end  110  of housing  100 . 
     According to an exemplary embodiment of the present disclosure, receptacles  140   a - 140   j  in second portion  104  of housing  100  may be semi-circular and partially open ( FIG. 6 ). Receptacles  140   a - 140   j  may adequately surround transmission lines  40   a - 40   j  to retain transmission lines  40   a - 40   j  therein while preventing lateral removal of transmission lines  40   a - 40   j  from receptacles  140   a - 140   j . To achieve such retention, receptacles  140   a - 140   j  may surround more than 180 degrees of each transmission line  40   a - 40   j . On the other hand, receptacles  140   a - 140   j  may be at least partially open, leaving transmission lines  40   a - 40   j  exposed to the explosive charge from detonators  20   a ,  20   b . To achieve such exposure, receptacles  140   a - 140   j  may surround less than 360 degrees of each transmission line  40   a - 40   j . For example, exemplary receptacles  140   a - 140   j  may surround about 190 degrees, 200 degrees, or 210 degrees of each transmission line  40   a - 40   j . Receptacles  120   a ,  120   b , in first portion  102  of housing  100 , on the other hand, may be circular to fully surround or encircle each detonator  20   a ,  20   b  ( FIG. 5 ). 
     When priming assembly  10  is assembled, transmission lines  40   a - 40   j  may surround detonators  20   a ,  20   b , as shown in  FIG. 5 , which is a cross-section taken in a direction perpendicular to longitudinal axis  106 . In other words, detonators  20   a ,  20   b , may extend centrally through housing  100  near longitudinal axis  106 , and transmission lines  40   a - 40   j  may be located radially outwardly from detonators  20   a ,  20   b , and longitudinal axis  106 . 
     Additionally, when priming assembly  10  is assembled, detonators  20   a ,  20   b , and transmission lines  40   a - 40   j  may longitudinally overlap in a direction perpendicular to longitudinal axis  106 , as shown in  FIG. 4 . For example, detonators  20   a ,  20   b , may extend beyond the interfacing plane P between first and second portions  102 ,  104 , of housing  100  (i.e., the interfacing plane P that contains adhesive layer  116 ) and into second portion  104  of housing  100  along with transmission lines  40   a - 40   j . Similarly, seals  42   a - 42   j  may longitudinally overlap detonators  20   a ,  20   b , in the direction perpendicular to longitudinal axis  106 , as shown in  FIG. 4 . For example, seals  42   a - 42   j  may extend beyond interfacing plane P and into first portion  102  of housing  100  along with detonators  20   a ,  20   b.    
     To ensure that the explosive charge from the detonators  20   a ,  20   b , is effectively conveyed or transmitted to transmission lines  40   a - 40   j , housing  100  may include or be packed with a booster material  150 , such as DETAPRIME, which is a flexible material that includes pentaerythritol tetranitrate (PETN). Booster material  150  may amplify or “boost” the energy released by detonators  20   a ,  20   b , to ensure that sufficient energy is delivered to detonate transmission lines  40   a - 40   j  and, in turn, to detonate cartridges  44   a - 44   j  and explosives  60 . The quantity of booster material  150  provided in housing  100  and the distance, if any, separating booster material  150  from detonators  20   a ,  20   b , and/or transmission lines  40   a - 40   j  may vary to achieve an effective communication of the explosive charge from detonators  20   a ,  20   b , to transmission lines  40   a - 40   j.    
     Booster material  150  may surround receptacles  120   a ,  120   b , in first portion  102  of housing  100  and/or may extend between receptacles  140   a - 140   j  in second portion  104  of housing  100 . In the illustrated embodiment of  FIGS. 2 and 4 , for example, booster material  150  includes two (2), hollow tubes  150   a ,  150   b , located between receptacles  140   a - 140   j  in second portion  104  of housing  100 , each booster tube  150   a ,  150   b , configured to receive a corresponding detonator  20   a ,  20   b , therein. Because transmission lines  40   a - 40   j  may be surrounded by receptacles  140   a - 140   j  on one side (i.e., the side closest to outer wall  105 ) and exposed on the other side (i.e., the side closest to the hollow interior  101  of housing  100 ), transmission lines  40   a - 40   j  may be exposed to booster material  150 . 
     The manner in which booster material  150  is retained within housing  100  may vary. In certain embodiments, booster material  150  may be retained within housing  100  by way of a friction-fit with detonator  20   a ,  20   b , transmission lines  40   a - 40   j , and/or part of housing  100 . In other embodiments, booster material  150  may be retained within housing  100  using a suitable adhesive, for example. In still other embodiments, booster material  150  may be retained within housing  100  by at least partially covering or enclosing output end  110  of housing  100 . 
     Priming assembly  10  may be at least partially pre-assembled before supplying priming assembly  10  to a user. For example, as shown in  FIG. 4 , transmission lines  40   a - 40   j  may be inserted into receptacles  140   a - 140   j  of housing  100  before supplying priming assembly  10  to the user. Also, housing  100  may be packed with booster material  150  before supplying priming assembly  10  to the user. After inserting transmission lines  40   a - 40   j  and/or booster material  150  into housing  100 , first and second portions  102 ,  104 , of housing  100  may be coupled together, such as with a suitable adhesive  116 , to close housing  100 . In this way, the user may only need to insert detonators  20   a ,  20   b , into housing  100  and couple transmission lines  40   a - 40   j  to explosives  60 , as shown in  FIG. 1 . It is also within the scope of the present disclosure that booster material  150  may be inserted into housing  100  along with or after detonators  20   a ,  20   b.    
     While this invention has been described as having preferred designs, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.