阅读说明：本技术 一种一体式漏电断路器 (Integral type electric leakage circuit breaker ) 是由 王琪 黄明芳 耿永强 俞小平 于 2021-08-23 设计创作，主要内容包括：本发明为一种一体式漏电断路器,N级壳体内设置有第一操作机构和第二操作机构,所述L级壳体内设置有L级操作结构,所述第一操作机构连接有N级手柄,所述L级操作机构连接有L级手柄,所述第二操作机构与所述L级操作机构联动连接,其中所述L级手柄带动N级手柄合闸时,所述L级操作机构、所述第一操作机构、所述第二操作机构同步合闸；所述L级手柄单独分闸时,所述L级操作机构与所述第二操作机构同步分闸；所述N级手柄带动L级手柄分闸时,所述L级操作机构、所述第一操作机构、所述第二操作机构同步分闸,所述N级手柄合闸时,所述第一操作机构合闸。本发明基于上述技术方案能够判断出断路器时由于何种原因分闸。(The invention relates to an integrated residual current circuit breaker, wherein a first operating mechanism and a second operating mechanism are arranged in an N-level shell, an L-level operating structure is arranged in an L-level shell, the first operating mechanism is connected with an N-level handle, the L-level operating mechanism is connected with an L-level handle, the second operating mechanism is in linkage connection with the L-level operating mechanism, and when the L-level handle drives the N-level handle to be switched on, the L-level operating mechanism, the first operating mechanism and the second operating mechanism are synchronously switched on; when the L-level handle is independently switched off, the L-level operating mechanism and the second operating mechanism are synchronously switched off; when the N-level handle drives the L-level handle to be switched off, the L-level operating mechanism, the first operating mechanism and the second operating mechanism are switched off synchronously, and when the N-level handle is switched on, the first operating mechanism is switched on. According to the technical scheme, the method can judge the reason for opening the breaker.)

1. An integrated residual current circuit breaker comprises an N-level shell, a middle shell and an L-level shell, and is characterized in that a first operating mechanism and a second operating mechanism are arranged in the N-level shell, an L-level operating structure is arranged in the L-level shell, the first operating mechanism is connected with an N-level handle, the L-level operating mechanism is connected with an L-level handle, the second operating mechanism is in linkage connection with the L-level operating mechanism, and when the L-level handle drives the N-level handle to switch on, the L-level operating mechanism, the first operating mechanism and the second operating mechanism synchronously switch on; when the L-level handle is independently switched off, the L-level operating mechanism and the second operating mechanism are synchronously switched off; when the N-level handle drives the L-level handle to be switched off, the L-level operating mechanism, the first operating mechanism and the second operating mechanism are switched off synchronously, and when the N-level handle is switched on, the first operating mechanism is switched on.

2. An integrated residual current circuit breaker according to claim 1, wherein the N-stage handle is formed with a stopper extending to the L-stage handle side, and the stopper is located on the closing direction side.

3. The integrated residual current circuit breaker as claimed in claim 2, wherein the second operating mechanism and the L-stage operating mechanism are provided with a linkage shaft, the linkage shaft passes through the intermediate housing from the L-stage operating mechanism to be arranged with the second operating mechanism, the second operating mechanism is correspondingly provided with an N-stage stationary contact, the L-stage operating mechanism is correspondingly provided with an L-stage stationary contact, in a closing state, an N-stage moving contact of the second operating mechanism is in contact with the N-stage stationary contact, and an L-stage moving contact of the L-stage operating mechanism is in contact with the L-stage stationary contact.

4. The integrated residual current circuit breaker according to claim 3, wherein the L-stage operating mechanism comprises an L-stage moving contact support, a first linkage hole is formed in the L-stage moving contact support, the second operating mechanism comprises a second support, a second linkage hole is formed in the second support, and the first linkage hole and the second linkage hole are arranged oppositely and connected through a linkage shaft.

5. An integrated residual current circuit breaker as claimed in claim 4, wherein a mounting post is formed on a side of said intermediate housing adjacent to said N-stage housing, said second support is fixed to said intermediate housing by said mounting post, said N-stage movable contact is disposed on said second support, said mounting post is recessed inwardly to form a hinge slot, a hinge shaft is disposed in said hinge slot, and said first operating mechanism is hinged to said intermediate housing by said hinge shaft.

6. The integrated residual current circuit breaker according to claim 5, wherein the first operating mechanism comprises a first support, the first support and the L-level moving contact support are both provided with a jump buckle and a lock catch, the jump buckle and the lock catch are hinged to the corresponding first support or the L-level moving contact support, the jump buckle is linked with the L-level handle or the N-level handle through a linkage rod, and the lock catch is matched with the jump buckle.

7. The integrated residual current circuit breaker according to claim 1 or 6, wherein a containing cavity is formed in one side of the middle housing close to the N-stage housing, the containing cavity is located between the N-stage stationary contact and the wiring terminal, an arc extinguishing system is arranged in the containing cavity, the arc extinguishing system comprises an arc extinguishing piece and a mounting base for fixing the arc extinguishing piece, and the arc extinguishing piece is clamped on the mounting base.

8. The integrated residual current circuit breaker according to claim 7, wherein the mounting base comprises a first mounting base and a second mounting base, the first mounting base and the second mounting base are integrally formed in the accommodating cavity, a clamping groove is formed in the first mounting base and the second mounting base, a clamping block is formed on the arc extinguishing piece, and the arc extinguishing piece is mounted on the mounting base through the clamping of the clamping groove and the clamping block.

9. The integrated residual current circuit breaker as claimed in claim 8, wherein the N-stage stationary contact is fixedly mounted on a stationary contact arc striking plate, the stationary contact arc striking plate is fixedly mounted on the middle housing, the wiring terminal is connected with a wiring board, the wiring board is fixed on the middle housing, a first magnetism increasing sheet is further disposed on an outer side of the stationary contact arc striking plate, one end of the wiring board extends to form an arc striking section, a second magnetism increasing sheet is disposed on an outer side of the arc striking section, a placement groove is formed on an inner side of the wiring terminal in the middle housing, a magnet is disposed in the placement groove, and the magnet is disposed on a side close to the arc striking section.

10. An integral residual current circuit breaker according to claim 9, characterized in that a cover is further provided outside said housing chamber, said cover being fixed to said intermediate case.

Technical Field

The invention relates to the technical field of circuit breakers, in particular to an integrated residual current circuit breaker.

Background

The leakage circuit breaker is widely applied, mainly used in industrial, commercial and civil residence places, and mainly used for short circuit overload protection and leakage protection.

The existing residual current circuit breaker comprises an N-level module and an L-level module, wherein the N-level module and the L-level module are both switched on and switched off simultaneously, but due to the fact that the switching on and off are conducted simultaneously, the switching-off reason can not be distinguished, and therefore the switching-off reason is necessary to be set.

Disclosure of Invention

The invention aims to provide an integrated residual current circuit breaker to solve the problems.

In order to achieve the purpose, the invention provides the following technical scheme:

an integrated residual current circuit breaker comprises an N-level shell, a middle shell and an L-level shell, and is characterized in that a first operating mechanism and a second operating mechanism are arranged in the N-level shell, an L-level operating structure is arranged in the L-level shell, the first operating mechanism is connected with an N-level handle, the L-level operating mechanism is connected with an L-level handle, the second operating mechanism is in linkage connection with the L-level operating mechanism, and when the L-level handle drives the N-level handle to switch on, the L-level operating mechanism, the first operating mechanism and the second operating mechanism synchronously switch on; when the L-level handle is independently switched off, the L-level operating mechanism and the second operating mechanism are synchronously switched off; when the N-level handle drives the L-level handle to be switched off, the L-level operating mechanism, the first operating mechanism and the second operating mechanism are switched off synchronously, and when the N-level handle is switched on, the first operating mechanism is switched on.

The invention is further provided that the N-level handle extends to one side of the L-level handle to form a stop block, and the stop block is positioned at one side of the closing direction.

The invention further provides that the second operating mechanism and the L-level operating mechanism are provided with linkage shafts, the linkage pump penetrates through the middle shell from the L-level operating mechanism to be arranged with the second operating mechanism, the second operating mechanism is correspondingly provided with N-level fixed contacts, the L-level operating mechanism is correspondingly provided with L-level fixed contacts, in a closing state, the N-level moving contact of the second operating mechanism is contacted with the N-level fixed contacts, and the L-level moving contact of the L-level operating mechanism is contacted with the L-level fixed contacts.

The invention further provides that the L-level operating mechanism comprises an L-level moving contact support, a first linkage hole is formed in the L-level moving contact support, the second operating mechanism comprises a second support, a second linkage hole is formed in the second support, and the first linkage hole and the second linkage hole are arranged oppositely and connected through a linkage shaft.

The invention further provides that a mounting column is formed on one side of the middle shell, which is close to the N-stage shell, the second support is fixed on the middle shell through the mounting column, the N-stage moving contact is arranged on the second support, the mounting column is inwards sunken to form a hinge groove, a hinge shaft is arranged in the hinge groove, and the first operating mechanism is hinged on the middle shell through the hinge shaft.

The invention further provides that the first operating mechanism comprises a first support, jump buckles and lock catches are arranged on the first support and the L-level moving contact support respectively, the jump buckles and the lock catches are hinged on the corresponding first support or the L-level moving contact support, the jump buckles are linked with the L-level handle or the N-level handle through a linkage rod, and the lock catches are matched with the jump buckles.

The invention further provides a containing cavity formed in one side, close to the N-stage shell, of the middle shell, the containing cavity is located between the N-stage static contact and the wiring terminal, an arc extinguishing system is arranged in the containing cavity, the arc extinguishing system comprises an arc extinguishing piece and an installation base used for fixing the arc extinguishing piece, and the arc extinguishing piece is clamped on the installation base.

The arc extinguishing piece is further arranged, the mounting base comprises a first mounting base and a second mounting base, the first mounting base and the second mounting base are integrally formed in the accommodating cavity, clamping grooves are formed in the first mounting base and the second mounting base, clamping blocks are formed on the arc extinguishing pieces, and the arc extinguishing pieces are mounted on the mounting bases through the clamping of the clamping grooves and the clamping blocks.

The invention further provides a static contact, wherein the N-stage static contact is fixedly arranged on a static contact arc striking plate, the static contact arc striking plate is fixedly arranged on the middle shell, a wiring board is connected to the wiring terminal and fixed on the middle shell, a first magnetism increasing sheet is further arranged on the outer side of the static contact arc striking plate, one end of the wiring board extends to form an arc striking section, a second magnetism increasing sheet is arranged on the outer side of the arc striking section, a placing groove is formed in the middle shell on the inner side of the wiring terminal, a magnet is arranged in the placing groove, and the magnet is arranged close to one side of the arc striking section.

The invention is further provided with a sealing cover outside the containing cavity, and the sealing cover is fixed on the middle shell.

The invention comprises at least one of the following beneficial effects:

1-the invention realizes the following functions by arranging an N-level handle, an L-level handle, a first operating mechanism, a second operating mechanism and an L-level operating mechanism which correspond to the N-level handle and the L-level handle;

(1) when the live wire is switched on, namely the L-level handle is switched on, the N-level handle is also switched on; so that the whole breaker is in a closing state;

(2) when the zero line is independently switched on, namely the N-level handle is switched on, the live line and the zero line are in a non-conduction state;

(3) when the live wire is separately switched off, namely the L-level handle is switched off, the short circuit or overload of the product is proved;

(4) when the zero line and the live line are jointly switched off, the switching-off is proved to be due to leakage protection;

2, a novel arc extinguishing system is arranged, and the arc extinguishing system adopts a plurality of parallel arc extinguishing plates arranged in the accommodating cavity, so that other accessories such as an arc extinguishing cover and the like are reduced, and the volume can be effectively reduced; the miniaturization of the residual current circuit breaker is realized; meanwhile, the first magnetism increasing sheet and the second magnetism increasing sheet are arranged on two sides of the arc extinguishing system correspondingly, so that the arc extinguishing effect is improved; in addition, a magnet is additionally arranged on one side of the second magnetism increasing sheet, so that the magnetic blowing effect is improved;

drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is an exploded view of an embodiment of the present invention;

FIG. 2 is an exploded view of an embodiment of the present invention with the middle housing removed;

FIG. 3 is a schematic view of a second operating mechanism according to the embodiment of the present invention;

FIG. 4 is a schematic view of the mounting of a second carrier and an L-stage contact carrier according to an embodiment of the invention;

FIG. 5 is a cross-sectional view of a second holder and an L-contact holder according to an embodiment of the invention;

FIG. 6 is an internal schematic diagram of an L-level module according to an embodiment of the present invention;

FIG. 7 is a perspective view of the embodiment of the present invention with the middle housing removed;

FIG. 8 is a perspective view of the embodiment of the present invention with the closure removed 1;

FIG. 9 is a perspective view of the embodiment of the present invention with the closure removed 2;

fig. 10 is a schematic structural diagram of a mounting base according to an embodiment of the invention.

Reference numeral, 10, N-stage housing; 20. a middle housing; 201. mounting a column; 2011. a hinge slot; 30. an L-stage shell; 40. a first operating mechanism; 401. a first bracket; 50. a second operating mechanism; 501. n-stage moving contacts; 502. a second bracket; 5021. a second linkage hole; 60. an L-level operating mechanism; 601. an L-level moving contact; 602. an L-level moving contact support; 6021. a first linkage hole; 70. an L-level handle; 80. an N-level handle; 80a, a stop block; 90. an electromagnetic trip assembly; 100. an electronic trip assembly; 110. a linkage shaft; 120. an N-stage static contact; 130. an L-stage static contact; 140. jumping and buckling; 150. locking; 160. a spring; 170. an accommodating chamber; 180. a wiring terminal; 190. an arc extinguishing sheet; 200. a first mounting base; 210. a second mounting base; 220. a clamping groove; 230. a clamping block; 240. a static contact arc striking plate; 250. a wiring board; 260. a first magnetism increasing sheet; 270. a second magnetism increasing sheet; 280. a placing groove; 290. a magnet; 300. sealing the cover; 310. a linkage rod;

Detailed Description

Embodiments of the present application will be described in detail with reference to the drawings and examples, so that how to implement technical means to solve technical problems and achieve technical effects of the present application can be fully understood and implemented.

Example 1:

as shown in fig. 1-6, the present invention is an integrated residual current circuit breaker, including an N-stage housing 10, an intermediate housing 20, and an L-stage housing 30, wherein a first operating mechanism 40 and a second operating mechanism 50 are disposed in the N-stage housing 10, an L-stage operating structure is disposed in the L-stage housing 30, the first operating mechanism 40 is connected to an N-stage handle 80, the L-stage operating mechanism 60 is connected to an L-stage handle 70, and the second operating mechanism 50 is linked to the L-stage operating mechanism 60, wherein when the L-stage handle 70 drives the N-stage handle 80 to be switched on, the L-stage operating mechanism 60, the first operating mechanism 40, and the second operating mechanism 50 are synchronously switched on; when the L-level handle 70 is independently opened, the L-level operating mechanism 60 and the second operating mechanism 50 are synchronously opened; when the N-level handle 80 drives the L-level handle 70 to open the brake, the L-level operating mechanism 60, the first operating mechanism 40, and the second operating mechanism 50 are synchronously opened, when the N-level handle 80 is closed, the first operating mechanism 40 is closed, in addition, an electromagnetic trip assembly 90 is correspondingly arranged on one side of the L-level operating mechanism 60, an electronic trip assembly 100 is correspondingly arranged on one side of the first operating mechanism 40, and based on the above principle, it can be determined what reason the circuit breaker is opened due to; simultaneously combines the following technical characteristics:

the N-level handle 80 extends towards one side of the L-level handle 70 to form a stop block 80a, the stop block 80a is positioned at one side of the closing direction, and the stop block 80a has the function of driving the N-level handle 80 to close when the L-level handle 70 is closed; during switching off, the N-level handle 80 drives the L-level handle 70 to switch off, but the independent switching off of the L-level handle 70 is not influenced, and the independent switching on of the N-level handle 80 is also avoided.

The following functions of the invention can be realized by combining the technical scheme:

(1) when the live wire is switched on, namely the L-level handle 70 is switched on, the N-level handle 80 is also switched on; so that the whole breaker is in a closing state;

(2) when the zero line is independently switched on, namely the N-level handle 80 is switched on, the live line and the zero line are in a non-conduction state;

(3) when the live wire is separately opened, namely the L-level handle 70 is opened, the short circuit or overload of the product is proved, and the electromagnetic tripping is realized;

(4) when the zero line and the live line are opened together, namely the N-level handle 80 drives the L-level handle 70 to open, the opening is proved to be caused by leakage protection, and the electronic tripping is realized;

the principle of tripping is described by matching with respective operating mechanisms, namely the following technologies:

the second operating mechanism 50 and the L-stage operating mechanism 60 are provided with a linkage shaft 110, the linkage pump passes through the intermediate housing 20 from the L-stage operating mechanism 60 and is arranged with the second operating mechanism 50, the second operating mechanism 50 is correspondingly provided with an N-stage fixed contact 120, the L-stage operating mechanism 60 is correspondingly provided with an L-stage fixed contact 130, in a closing state, the N-stage moving contact 501 of the second operating mechanism 50 is in contact with the N-stage fixed contact 120, the L-stage moving contact 601 of the L-stage operating mechanism 60 is in contact with the L-stage fixed contact 130, the L-stage operating mechanism 60 comprises an L-stage moving contact support 602, the L-stage moving contact 601 is arranged on the L-stage moving contact support 602, the L-stage moving contact support 602 is provided with a first linkage hole 6021, the second operating mechanism 50 comprises a second support 502, and the second support 502 is provided with a second linkage hole 5021, the first linkage hole 6021 and the second linkage hole 5021 are oppositely arranged and connected through a linkage shaft 110, a mounting column 201 is formed on one side of the middle shell 20 close to the N-stage shell 10, the second support 502 is fixed on the middle shell 20 through the mounting column 201, the N-stage moving contact 501 is arranged on the second support 502, a hinge groove 2011 is formed by inward sinking of the mounting column 201, a hinge shaft (not shown in the figure) is arranged in the hinge groove 2011, and the first operating mechanism 40 is hinged on the middle shell 20 through the hinge shaft.

The first operating mechanism 40 includes a first support 401, the first support 401 and the L-level movable contact support 602 are both provided with a trip 140 and a latch 150, the trip 140 and the latch 150 are hinged to the corresponding first support 401 or the L-level movable contact support 602, the trip 140 is linked with the L-level handle 70 or the N-level handle 80 through a linkage rod 310, the latch 150 is matched with the trip 140, a spring 160 is further installed on the L-level movable contact support 602, two ends of the spring 160 respectively abut against the L-level movable contact support 602 and the L-level housing 30, and the L-level handle 70 provides a restoring force when resetting during opening.

In the switching-on process, the L-level handle 70 and the N-level rotate to the switching-on position, but at this time, since the trip 140 and the latch 150 are in the state of abutting limitation, the linkage rod 310 pushes the entire L-level movable contact support 602 to rotate, and at the same time, the second support 502 of the second operating mechanism 50 also rotates, so that the contact between the movable contact and the fixed contact in the N-level and the L-level is realized, and the L-level and the movable contact are in the conducting state; when the product is overloaded or short-circuited, the electromagnetic trip is acted, the push rod pushes the latch 150, and the limiting effect of the latch 150 and the trip 140 is released, so that the L-stage moving contact 601 of the L-stage operating mechanism 60 is driven to be separated from the L-stage static contact 130, and meanwhile, the N-stage moving contact 501 and the N-stage static contact 120 on the second operating mechanism 50 are driven to be separated, and the N-stage handle 80 is not opened at this time;

when the N-level handle 80 is opened, the electronic tripping is used for realizing, and at the moment, the N-level handle 80 drives the L-level handle 70 to be opened together;

example 2:

most of the existing residual current circuit breakers contain N-level modules, so that corresponding arc extinguishing systems are arranged in the two modules, but most of the existing arc extinguishing systems are in a form that an arc extinguishing sheet 190 is arranged in an arc extinguishing cover, and the size of the existing arc extinguishing systems is large, so that the size of the whole N level is also increased, and in order to solve the technical problems, the invention further adopts the following technical scheme:

as shown in fig. 7-10, an accommodating cavity 170 is formed at one side of the middle housing 20 close to the N-stage housing 10, the accommodating cavity 170 is located between the N-stage stationary contact 120 and the wiring terminal 180, an arc extinguishing system is disposed in the accommodating cavity 170, the arc extinguishing system includes an arc extinguishing plate 190 and a mounting base for fixing the arc extinguishing plate 190, the arc extinguishing plate 190 is clamped on the mounting base, the mounting base includes a first mounting base 200 and a second mounting base 210, the first mounting base 200 and the second mounting base 210 are integrally formed in the accommodating cavity 170, clamping grooves 220 are formed in the first mounting base 200 and the second mounting base 210, clamping blocks 230 are formed on the arc extinguishing plate 190, the arc extinguishing plate 190 is mounted on the mounting base through clamping of the clamping grooves 220 and the clamping blocks 230, the N-stage fixed contact 120 is fixedly mounted on a fixed contact arc striking plate 240, the fixed contact arc striking plate 240 is fixedly mounted on the middle housing 20, the wiring board 250 is connected to the wiring terminal 180, the wiring board 250 is fixed on the middle housing 20, a first magnetism increasing sheet 260 is further arranged on the outer side of the fixed contact arc striking plate 240, one end of the wiring board 250 extends to form an arc striking section, a second magnetism increasing sheet 270 is arranged on the outer side of the arc striking section, a mounting groove 280 is formed in the middle housing 20 on the inner side of the wiring terminal 180, a magnet 290 is arranged in the mounting groove 280, the magnet 290 is arranged on one side close to the arc striking section, a sealing cover 300 is further arranged on the outer side of the accommodating cavity 170, the sealing cover 300 is fixed on the middle housing 20, and the novel arc extinguishing system is arranged by adopting a plurality of parallel arc extinguishing sheets 190 arranged in the accommodating cavity 170, other accessories such as an arc extinguishing chamber and the like are reduced, and the volume can be effectively reduced; the miniaturization of the residual current circuit breaker is realized; meanwhile, the first magnetism-increasing sheet 260 and the second magnetism-increasing sheet 270 are arranged on two sides of the arc extinguishing system, so that the arc extinguishing effect is improved; in addition, a magnet 290 is additionally arranged on one side of the second magnetism increasing sheet 270, so that the magnetic blowing effect is improved;

certain terms are used throughout the description and claims to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect.

More use is made of shells such as class 10, N; 20. a middle housing; 201. mounting a column; 2011. a hinge slot; 30. an L-stage shell; 40. a first operating mechanism; 401. a first bracket; 50. a second operating mechanism; 501. n-stage moving contacts; 502. a second bracket; 5021. a second linkage hole; 60. an L-level operating mechanism; 601. an L-level moving contact; 602. an L-level moving contact support; 6021. a first linkage hole; 70. an L-level handle; 80. an N-level handle; 80a, a stop block; 90. an electromagnetic trip assembly; 100. an electronic trip assembly; 110. a linkage shaft; 120. an N-stage static contact; 130. an L-stage static contact; 140. jumping and buckling; 150. locking; 160. a spring; 170. an accommodating chamber; 180. a wiring terminal; 190. an arc extinguishing sheet; 200. a first mounting base; 210. a second mounting base; 220. a clamping groove; 230. a clamping block; 240. a static contact arc striking plate; 250. a wiring board; 260. a first magnetism increasing sheet; 270. a second magnetism increasing sheet; 280. a placing groove; 290. a magnet; 300. sealing the cover; 310. linkage rods and the like, it is noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or system comprising a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such article or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element.

While the foregoing description shows and describes several preferred embodiments of the invention, it is to be understood, as noted above, that the invention is not limited to the forms disclosed herein, but is not intended to be exhaustive of other embodiments, and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as expressed herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.