RCC-based low-power-consumption Bluetooth technology-based door access control device capable of realizing non-inductive door opening
Technical Field
The invention relates to the field of entrance guard machines, in particular to entrance guard machine equipment for realizing non-inductive door opening based on RCC (remote control center) low-power-consumption Bluetooth technology.
Background
With the continuous development of society, the living standard is continuously improved, and the safety of coming in and going out becomes a concern of people. Along with the development of economy and the application of emerging technologies, the access control is continuously developed towards safety and convenience, namely, the access control is realized by a traditional mechanical door lock to an electronic magnetic card lock and an electronic coded lock, and then the access control is realized by the electronic magnetic card lock and the electronic coded lock to an access control system. The intelligent era brought by the Internet of things also enables the familiar entrance guard market to have obvious changes, and the intelligent entrance guard system is combined with the intelligent security system, so that the safety performance is optimized and upgraded, and more intelligent home applications are realized by integrating with the property management system. With the increasing maturity of WiFi and bluetooth technologies, the security of wireless data communication and the stability of transmission data are guaranteed, and more intelligent access control is widely applied to management control systems, and becomes an important component of systems such as houses, buildings, banks, and the like.
At present, a large amount of heats of current entrance guard's quick-witted internal component during operation heat dissipation, guarantee the normal use of entrance guard's machine internal component for the heat that discharges, set up the heat dissipation through-hole on the entrance guard's casing usually, through the heat dissipation through-hole with the inside heat discharge of entrance guard's casing, outside dust impurity and aqueous vapor get into inside the entrance guard's casing through the heat dissipation through-hole easily simultaneously, cause the influence to the inside component of entrance guard's casing, thereby the life of entrance guard's machine has been reduced.
Therefore, it is necessary to provide an access control device for realizing a non-inductive door opening based on the RCC bluetooth low energy technology to solve the above problems.
Disclosure of Invention
The invention aims to provide an entrance guard device for realizing non-inductive door opening based on RCC low-power Bluetooth technology, the first heat dissipation mechanism is arranged at the rear side of the door lock casing and consists of a heat absorption sheet, a first semiconductor refrigeration sheet, a first heat conduction plate, a second semiconductor refrigeration sheet, a first heat dissipation plate and a heat dissipation fan from inside to outside in sequence, so that heat on the control mainboard can be effectively conducted out for heat dissipation, the left side and the right side of the door control machine shell are respectively provided with a second heat dissipation mechanism, the second heat dissipation mechanism consists of a heat absorption plate, a third semiconductor refrigeration sheet, a second heat conduction plate and a second heat dissipation plate from inside to outside in sequence, the heat in the door control machine shell can be effectively conducted to the outside for heat dissipation, and the heat dissipation of a through hole does not need to be formed on the shell of the entrance guard machine, so that the sealing performance of the whole shell of the entrance guard machine is good, and the defects in the technology are overcome.
In order to achieve the above purpose, the invention provides the following technical scheme: the entrance guard equipment for realizing the non-inductive door opening based on the RCC low-power-consumption Bluetooth technology comprises an entrance guard system, an entrance guard casing and a control mainboard, wherein the control mainboard is installed on the inner wall of the rear side of the entrance guard casing, the entrance guard system comprises a single-chip, a BLE Bluetooth module, an electronic lock driving module and a mobile phone terminal, the single-chip and the BLE Bluetooth module are both installed on the control mainboard, the single-chip is in two-way communication connection with the BLE Bluetooth module, the output end of the single-chip is electrically connected with the input end of the electronic lock driving module, the mobile phone terminal is provided with a mobile phone Bluetooth module and Bluetooth entrance guard APP software, the mobile phone Bluetooth module is in two-way communication connection with the BLE Bluetooth module, the rear side of the entrance guard casing is provided with a first heat dissipation mechanism, and the left side and the right side of the entrance guard casing are both provided with second heat dissipation mechanisms;
the first heat dissipation mechanism comprises a first heat conduction plate, the first heat conduction plate is embedded on the rear side wall of the door control shell, the first heat conduction plate penetrates through the inner side and the outer side of the rear side wall of the door control shell, a first semiconductor refrigeration piece is fixed on the inner side of the first heat conduction plate, a heat absorption piece is fixed on the inner side of the first semiconductor refrigeration piece, the heat absorption piece is abutted against the control mainboard, a temperature sensor is arranged between the heat absorption piece and the control mainboard, a second semiconductor refrigeration piece is fixed on the outer side of the first heat conduction plate, a first heat dissipation plate is fixed on the outer side of the second semiconductor refrigeration piece, a heat dissipation fan is fixed on the outer side of the first heat dissipation plate, the second heat dissipation mechanism comprises a second heat conduction plate, the second heat conduction plate is embedded on the side wall of the door control shell, and penetrates through the inner side and the outer side of the side wall of the door control shell, the inner side of the second heat conducting plate is fixedly provided with a third semiconductor refrigeration piece, the inner side of the third semiconductor refrigeration piece is fixedly provided with a heat absorbing plate, and the outer side of the second heat conducting plate is fixedly provided with a second heat radiating plate.
Preferably, the output end of the temperature sensor is electrically connected with the input end of the single chip, and the output end of the single chip is electrically connected with the input ends of the first semiconductor refrigeration chip, the second semiconductor refrigeration chip, the cooling fan and the third semiconductor refrigeration chip respectively.
Preferably, the first heat conducting plate is made of copper materials, the second heat conducting plate is made of copper materials, the heat absorbing sheet is a heat conducting silica gel sheet, and the heat absorbing sheet is bonded with the control main board through heat conducting silicone grease.
Preferably, the first heat dissipation plate is provided with strip-shaped heat dissipation fins at equal intervals on one side close to the heat dissipation fan, and the strip-shaped heat dissipation fins and the first heat dissipation plate are integrally machined and molded.
Preferably, the side of the heat absorbing plate far away from the third semiconductor refrigeration piece is equidistantly provided with heat absorbing convex strips, the heat absorbing convex strips and the heat absorbing plate are integrally formed by heat conducting silica gel, and grooves are formed in the side of the second heat dissipation plate far away from the second heat conduction plate at equal intervals.
Preferably, the access control system comprises a storage module, the storage module is arranged on the control mainboard, and the single-chip and the storage module are in two-way communication connection.
Preferably, access control system includes display screen, pilot lamp and built-in speaker, the front side at the entrance guard's casing is installed to display screen and pilot lamp, the pilot lamp is the bar pilot lamp, the pilot lamp is located the top of display screen, the inside at the entrance guard's casing is installed to built-in speaker, the output of singlechip respectively with display screen, pilot lamp and built-in speaker's input electric connection.
Preferably, the internally mounted of entrance guard's casing has reserve battery, electric connection between reserve battery's the output and the input of control mainboard.
Preferably, the rear side of entrance guard's casing is provided with the protective frame, pass through bolted connection between protective frame and the entrance guard's casing, radiator fan nestification is in the protective frame, the one end port that the entrance guard's casing was kept away from to the protective frame is fixed with first dust screen, the equipartition interval in the left and right sides of protective frame has seted up heat dissipation bar hole, the port in heat dissipation bar hole is fixed with the second dust screen.
Preferably, the upper end and the lower end of the rear side of the protection frame are both fixed with mounting seats, the mounting seats and the protection frame are integrally machined, and mounting holes are formed in the mounting seats.
In the technical scheme, the invention provides the following technical effects and advantages:
1. the first heat dissipation mechanism is arranged at the rear side of the door lock casing and consists of a heat absorption sheet, a first semiconductor refrigeration sheet, a first heat conduction plate, a second semiconductor refrigeration sheet, a first heat dissipation plate and a heat dissipation fan from inside to outside in sequence, so that heat on the control mainboard can be effectively conducted out for heat dissipation, the left side and the right side of the door control machine shell are respectively provided with a second heat dissipation mechanism, the second heat dissipation mechanism consists of a heat absorption plate, a third semiconductor refrigeration sheet, a second heat conduction plate and a second heat dissipation plate from inside to outside in sequence, the heat in the door control machine shell can be effectively conducted to the outside for heat dissipation, the heat dissipation effect of the door control machine is further improved, the heat dissipation of the door access machine shell is not required to be provided with a through hole, so that the whole door access machine shell has good sealing performance, external dust and water vapor are difficult to enter the door access machine shell, and the service life of the door access machine is prolonged;
2. the BLE Bluetooth module is arranged on the control main board and is in communication connection with the mobile phone Bluetooth module of the mobile phone terminal, when a user carries the mobile phone terminal to be close to the periphery of the access control machine, the mobile phone Bluetooth module is automatically connected with the inside of the access control machine, the identity is verified by interactive data, and after the identity is verified, the single chip controls the electronic lock driving module to work to open the door, so that the whole process is quick, stable and efficient, the constraint of a traditional large string of keys and access control cards is eliminated, the management and maintenance of the access control cards are not needed, and the cost is saved;
3. the temperature sensor is arranged between the heat absorbing sheet and the control mainboard, the temperature sensor detects the temperature of the control mainboard in real time, when the temperature of the control mainboard reaches or exceeds the set highest temperature, the single sheet controls the control of the heat radiating fan, the heat radiating efficiency is improved, and when the temperature sensor detects the temperature of the control mainboard in real time and does not reach the set temperature, the heat radiating fan does not work, and the loss is reduced;
4. the indicating lamp is arranged on the front side of the door access machine shell, the built-in loudspeaker is arranged in the door access machine shell, when the identity verification is passed, the indicating lamp is turned on, and meanwhile, the built-in loudspeaker carries out voice prompt, so that the using effect of the door access machine is improved;
5. the rear side through at the entrance guard's casing is fixed with the protective frame, can protect radiator fan, avoids radiator fan to expose for a long time and outside and cause the damage, and the thermal discharge in the protective frame is convenient for in the port of protective frame rear side and the heat dissipation bar hole that the lateral wall was seted up simultaneously does not influence the heat dissipation of first heat dissipation mechanism.
Drawings
In order to more clearly illustrate the embodiments of the present application or technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings can be obtained by those skilled in the art according to the drawings.
FIG. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 is an overall perspective view of the present invention;
FIG. 3 is a schematic view of FIG. 2 with the first dust screen removed in accordance with the present invention;
FIG. 4 is a front cross-sectional view of the present invention;
FIG. 5 is an exploded view of a first heat dissipation mechanism of the present invention;
FIG. 6 is an exploded view of a second heat dissipation mechanism of the present invention;
fig. 7 is a schematic view of the access control system of the present invention.
Description of reference numerals:
1 entrance guard's casing, 2 control mainboards, 3 singlechips, 4BLE bluetooth module, 5 electronic lock drive module, 6 mobile phone terminals, 7 mobile phone bluetooth module, 8 first heat-conducting plates, 9 first semiconductor refrigeration piece, 10 heat-absorbing pieces, 11 temperature sensor, 12 second semiconductor refrigeration piece, 13 first heating panel, 14 radiator fan, 15 second heat-conducting plates, 16 third semiconductor refrigeration piece, 17 heat-absorbing plates, 18 second heating panel, 19 bar fin, 20 heat-absorbing convex strip, 21 recess, 22 protection frame, 23 first dust screen, 24 heat dissipation bar holes, 25 second dust screen, 26 mount pads, 27 bluetooth entrance guard APP software, 28 spare battery, 29 storage module, 30 display screen, 31 pilot lamp, 32 built-in speakers.
Detailed Description
In order to make the technical solutions of the present invention better understood, those skilled in the art will now describe the present invention in further detail with reference to the accompanying drawings.
The invention provides an entrance guard device for realizing non-inductive door opening based on RCC low-power consumption Bluetooth technology, which comprises an entrance guard system, an entrance guard shell 1 and a control mainboard 2, wherein the control mainboard 2 is arranged on the inner wall of the rear side of the entrance guard shell 1, the entrance guard system comprises a single-machine piece 3, a BLE Bluetooth module 4, an electronic lock driving module 5 and a mobile phone terminal 6, the single-machine piece 3 and the BLE Bluetooth module 4 are both arranged on the control mainboard 2, the single-machine piece 3 is in bidirectional communication connection with the BLE Bluetooth module 4, the output end of the single-machine piece 3 is electrically connected with the input end of the electronic lock driving module 5, the mobile phone terminal 6 is provided with a mobile phone Bluetooth module 7 and Bluetooth entrance guard APP software 27, the mobile phone Bluetooth module 7 is in bidirectional communication connection with the BLE Bluetooth module 4, and the communication between the mobile phone terminal 6 and the single-machine piece 3 is realized, a first heat dissipation mechanism is arranged on the rear side of the entrance guard housing 1, and second heat dissipation mechanisms are arranged on the left side and the right side of the entrance guard housing 1;
the first heat dissipation mechanism comprises a first heat conduction plate 8, the first heat conduction plate 8 is embedded on the rear side wall of the door control shell 1, the first heat conduction plate 8 penetrates through the inner side and the outer side of the rear side wall of the door control shell 1, a first semiconductor refrigeration sheet 9 is fixed on the inner side of the first heat conduction plate 8, a heat absorption sheet 10 is fixed on the inner side of the first semiconductor refrigeration sheet 9, the heat absorption sheet 10 is abutted against the control mainboard 2, a temperature sensor 11 is arranged between the heat absorption sheet 10 and the control mainboard 2, a second semiconductor refrigeration sheet 12 is fixed on the outer side of the first heat conduction plate 8, a first heat dissipation plate 13 is fixed on the outer side of the second semiconductor refrigeration sheet 12, a heat dissipation fan 14 is fixed on the outer side of the first heat dissipation plate 13, the second heat dissipation mechanism comprises a second heat conduction plate 15, and the second heat conduction plate 15 is embedded on the side wall of the door control shell 1, the second heat-conducting plate 15 runs through the inner side and the outer side of the side wall of the door control device shell 1, a third semiconductor refrigerating sheet 16 is fixed on the inner side of the second heat-conducting plate 15, a heat absorbing plate 17 is fixed on the inner side of the third semiconductor refrigerating sheet 16, and a second heat radiating plate 18 is fixed on the outer side of the second heat-conducting plate 15.
The output of temperature sensor 11 and the input electric connection of unit piece 3, the output of unit piece 3 respectively with the input electric connection of first semiconductor refrigeration piece 9, second semiconductor refrigeration piece 12, radiator fan 14 and third semiconductor refrigeration piece 16, temperature sensor 11 sends the temperature information that detects for unit piece 3, and unit piece 3 handles the back and controls first semiconductor refrigeration piece 9, second semiconductor refrigeration piece 12, radiator fan 14 and the work of third semiconductor refrigeration piece 16 according to temperature information.
The access control system comprises a storage module 29, wherein the storage module 29 is arranged on the control mainboard 2, the single chip 3 is in two-way communication connection with the storage module 29, and the storage module 29 can store user information so as to facilitate identity authentication during data interaction.
The implementation mode is specifically as follows: BLE4.2 Bluetooth module SKB369 developed by BLE Bluetooth module 4 by adopting Nordic nRF52832 chip scheme, a user downloads corresponding Bluetooth entrance guard APP software 33 from a mobile phone terminal 6 for identity registration, when the user carries the mobile phone terminal 6 to be close to the periphery of an entrance guard, the mobile phone Bluetooth module 7 is automatically connected with the BLE Bluetooth module 4 in the entrance guard, the mobile phone terminal 6 sends a signal to a single machine piece 3 in the entrance guard and starts to exchange data to complete identity verification, after the identity verification is passed, the single machine piece 3 controls an electronic lock driving module 5 to work for opening a door, then Bluetooth is automatically disconnected, the next user is waited for connection, the whole process is fast, stable and efficient, a first heat dissipation mechanism is arranged on the rear side of the entrance guard housing 1, second heat dissipation mechanisms are arranged on the left side and the right side of the entrance guard housing 1, and the first heat dissipation mechanism sequentially comprises a heat absorption piece 10 and a first semiconductor refrigeration piece 9 from inside to outside, The heat dissipation mechanism comprises a first heat conduction plate 8, a second semiconductor refrigeration piece 12, a first heat dissipation plate 13 and a heat dissipation fan 14, wherein the heat absorption piece 10 is contacted with the control mainboard 2, the heat on the control mainboard 2 sequentially passes through the heat absorption piece 10, the first semiconductor refrigeration piece 9, the first heat conduction plate 8 and the second semiconductor refrigeration piece 12, and is finally dissipated through the first heat dissipation plate 13, the heat on the control mainboard 2 is conducted out of the access control machine shell 1 for heat dissipation, so that the heat dissipation effect of the control mainboard 2 is improved, the second heat dissipation mechanism sequentially comprises a heat absorption plate 17, a third semiconductor refrigeration piece 16, a second heat conduction plate 15 and a second heat dissipation plate 18 from inside to outside, the heat inside the access control machine shell 1 sequentially passes through the heat absorption plate 17, the third semiconductor refrigeration piece 16 and the second heat conduction plate 15, and is finally dissipated through the second heat dissipation plate 18, the heat inside the access control machine shell 1 can be conducted out, and the heat dissipation effect inside the access control machine shell 1 is further improved, and does not need to set up the through hole to dispel the heat on the housing 1 of the entrance guard, make the housing 1 of the whole entrance guard good airproof, outside dust and aqueous vapor are difficult to enter the housing 1 of the entrance guard, has lengthened the service life of the entrance guard, there are temperature pick-ups 11 between heat-absorbing fin 10 and control mother board 2, the temperature pick-up 11 detects the temperature of the control mother board 2 in real time, when the temperature of the control mother board 2 reaches or exceeds the maximum temperature presumed, the single-machine fin 3 controls the heat-dissipating fan 14 to control, raise the heat-dissipating efficiency, when the temperature pick-up 11 detects the temperature of the control mother board 2 in real time and does not reach the temperature presumed, the heat-dissipating fan 14 is out of work, reduce the loss, this embodiment has solved and set up the heat-dissipating through hole on the housing of the entrance guard existing in the prior art specifically, discharge the heat in the housing of the entrance guard through the heat-dissipating through hole, outside dust impurity and aqueous vapor are easy to enter the housing of the entrance guard at the interior through the heat-dissipating through hole at the housing, the influence is caused to the elements inside the shell of the door access machine, thereby reducing the service life of the door access machine.
As shown in fig. 1, fig. 3 and fig. 5-6, the first heat conducting plate 8 is made of copper material, the second heat conducting plate 15 is made of copper material, the heat transfer function of the copper plate is good, the heat inside the copper plate can be conducted out, the heat absorbing sheet 10 is a heat conducting silica gel sheet, the heat absorbing sheet 10 is bonded with the control main board 2 through heat conducting silicone grease, the heat conducting effect of the heat conducting silica gel sheet is good, and the heat absorbing sheet 10 can effectively conduct the heat on the control main board 2.
First heating panel 13 is close to radiator fan 14 one side equidistant bar fin 19 that is equipped with, integration machine-shaping between bar fin 19 and the first heating panel 13 has improved the joint strength between bar fin 19 and the first heating panel 13, has reduced the processing degree of difficulty, and bar fin 19 has increased the area of contact of air simultaneously, has improved the radiating efficiency.
One side that third semiconductor refrigeration piece 16 was kept away from to absorber plate 17 is equidistant to be equipped with heat absorption sand grip 20, has increased the area of contact with the inside air of entrance guard's casing 1, can drive the heat of entrance guard's casing 1 inside effectively, heat absorption sand grip 20 adopts heat conduction silica gel integration machine-shaping with absorber plate 17, has improved the joint strength between heat absorption sand grip 20 and the absorber plate 17, has reduced the processing degree of difficulty, one side that second heat-conducting plate 15 was kept away from to second heating panel 18 is equidistant to be seted up flutedly 21, has increased the area of contact of second heating panel 18 with the outside air, has improved the radiating efficiency.
The implementation mode is specifically as follows: the heat absorbing sheet 10 is set to be a heat conducting silica gel sheet, the heat absorbing sheet 10 is bonded with the control mainboard 2 through heat conducting silicone grease, so that the heat absorbing sheet 10 is tightly contacted with the control mainboard 2, the heat absorbing sheet 10 can effectively conduct heat on the control mainboard 2, heat absorbing convex strips 20 are arranged on the heat absorbing plate 17 at equal intervals, the contact area with the air inside the entrance guard shell 1 is increased, the heat inside the entrance guard shell 1 can be effectively transmitted, the first heat conducting plate 8 and the second heat conducting plate 15 are both made of copper materials, the structure strength is high, the door is not easy to damage, the heat conducting performance is excellent, the heat can be effectively conducted, the internal heat is outwards conducted, strip-shaped radiating fins 19 are arranged at equal intervals on the outer side of the first radiating plate 13, grooves 21 are arranged at equal intervals on the outer side of the second radiating plate 18, and the contact area between the first radiating plate 13 and the second radiating plate 18 and the external air is increased, the heat dissipation efficiency is improved, and the problem that the heat dissipation effect is poor due to the fact that the heat absorption area of the heat absorption plate and the heat dissipation area of the heat dissipation plate are small in the prior art is solved.
As shown in fig. 1, 4 and 7, access control system includes display screen 30, pilot lamp 31 and built-in speaker 32, display screen 30 and pilot lamp 31 are installed in the front side of access control machine casing 1, pilot lamp 31 is the bar pilot lamp, pilot lamp 31 is located the top of display screen 30, built-in speaker 32 is installed in access control machine casing 1's inside, the output of singlechip 3 respectively with display screen 30, pilot lamp 31 and built-in speaker 32's input electric connection, when the identity is verified and is passed, pilot lamp 31 lights, built-in speaker 32 carries out voice prompt simultaneously, has improved access control machine result of use.
The internally mounted of entrance guard's casing 1 has reserve battery 28, electric connection between reserve battery 28's the output and the input of control mainboard 2, when having a power failure because of the accident, reserve battery 28 can provide the electric quantity, guarantees entrance guard's normal work.
The implementation mode is specifically as follows: when the user carries cell-phone terminal 6 and is close to around the access control machine, begin the verification of mutual data completion identity, when verifying when passing, 3 control indicator lamps 31 of unit piece light, built-in speaker 32 carries out the voice prompt who passes through simultaneously, show user information on the display screen 30, when verifying the failure, indicator lamp 31 does not light, built-in speaker 32 carries out the voice prompt who does not pass through, the suggestion effect is good, the result of use has been improved, the internally mounted of access control machine casing 1 has reserve battery 28, when unexpected power failure, reserve battery 28 can provide the electric quantity for access control machine internal component work, the access control machine can normally work when guaranteeing to have a power failure, the poor problem of access control machine suggestion effect that exists among the prior art has specifically been solved to this embodiment.
As shown in fig. 1-3, entrance guard's casing 1's rear side is provided with protective frame 22, pass through bolted connection between protective frame 22 and the entrance guard's casing 1, radiator fan 14 nestification is in protective frame 22, protective frame 22 keeps away from entrance guard's casing 1 one end port and is fixed with first dust screen 23, heat dissipation bar hole 24 has been seted up to the impartial interval in the left and right sides of protective frame 22, the port of heat dissipation bar hole 24 is fixed with second dust screen 25, can protect radiator fan 14 through protective frame 22, avoids radiator fan 14 to expose for a long time and cause the damage outside, has protected radiator fan 14.
The upper and lower both ends of protective frame 22 rear side all are fixed with mount pad 26, integrated processing sets up between mount pad 26 and the protective frame 22, the mounting hole has been seted up on the mount pad 26, and the installation of the entrance guard machine of being convenient for through mount pad 26 is fixed, is convenient for fix the entrance guard machine on the wall.
The implementation mode is specifically as follows: the rear side of the door access machine shell 1 is provided with a protective frame 22, the upper end and the lower end of the rear side of the protective frame 22 are both fixed with a mounting seat 26, the protective frame 22 is fixed on the wall through the mounting seat 26, so that the door access machine is installed on the door access machine, the protective frame 22 covers the outer side of a radiating fan 14 and can protect the radiating fan 14 to avoid the damage caused by long-time exposure of the radiating fan 14, the left side and the right side of the protective frame 22 are equally provided with radiating strip-shaped holes 24, the exchange of the air inside the protective frame 22 and the outside air can be realized through the radiating strip-shaped holes 24, the heat emission is convenient, the heat dissipation of a first radiating mechanism is not influenced, the port of the radiating strip-shaped hole 24 is fixed with a second dustproof net 25, the dust can be prevented from entering the protective frame 22 and being accumulated to cover the surfaces of the radiating fan 14 and the first radiating plate 13, the radiating effect is improved, and the embodiment specifically solves the problem that the radiating fan existing in the prior art is exposed outside, on which dust is easily accumulated and easily damaged.
While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that the described embodiments may be modified in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are illustrative in nature and should not be construed as limiting the scope of the invention.