阅读说明：本技术 一种消防员救生自动保护方法 (Automatic protection method for firefighter lifesaving ) 是由 陈忠辉 陈辉 于 2021-01-09 设计创作，主要内容包括：本发明公开了一种消防员救生自动保护方法,包括：浓烟消除步骤：当进入火场时启动双向电机从而带动风扇轴转动,通过风扇轴的转动带动风扇旋转向右产生风力；坠物阻挡步骤：若有物体从上方坠落,坠落物先落在伸缩板上端面,当物体较重时将伸缩板向下压,此时绷紧伸缩弹簧的同时固定齿条块能够向上延伸并穿过让位腔而向上伸出至伸缩板上侧,此时伸缩板向下移动并由于限位块的支撑而无法继续向下,此时通过升降块的向下移动从而与接触开关接触,当接触开关被接触时电磁铁不再吸附磁块从而通过离合弹簧的推力推动切换锥齿轮向下移动与风扇锥齿轮啮合传动,此时通过连接块的转动从而带动伸缩板转动,从而带动左右两侧伸缩块转动扩大防护坠物的面积。(The invention discloses an automatic protection method for firefighter lifesaving, which comprises the following steps: dense smoke elimination step: when the electric fan enters a fire scene, the bidirectional motor is started so as to drive the fan shaft to rotate, and the fan is driven to rotate to the right by the rotation of the fan shaft to generate wind power; a step of stopping falling objects: if there is the object to fall from the top, the thing that falls earlier at the expansion plate up end, push down the expansion plate when the object is heavier, fixed rack piece can upwards extend and pass the chamber of stepping down and upwards stretch out to the expansion plate upside when tightening expanding spring this moment, the expansion plate downstream and can't continue downwards because of the support of stopper this moment, thereby the downstream and the contact switch contact through the elevator this moment, thereby the electro-magnet is no longer adsorbed the magnetic path and is switched bevel gear downstream and fan bevel gear meshing transmission through clutch spring's thrust promotion when contact switch is contacted, thereby it rotates to drive the expansion plate this moment through the rotation of connecting block, thereby it rotates the area that enlarges the protection thing to drive left and right sides expansion block.)

1. An automatic protection method for firefighter lifesaving is characterized by comprising the following steps:

dense smoke elimination step: when entering a fire scene, the bidirectional motor is started to drive the fan shaft to rotate, and the fan is driven to rotate to generate wind power rightwards through the rotation of the fan shaft, so that the interference of dense smoke on firemen is reduced;

a step of stopping falling objects: if an object falls from the upper part, the falling object firstly falls on the upper end surface of the expansion plate, when the object is heavier, the expansion plate is pressed downwards to drive the lifting block to move downwards, at the moment, the expansion spring is tightened, meanwhile, the fixed rack block can extend upwards and penetrate through the abdicating cavity to extend upwards to the upper side of the expansion plate, at the moment, the expansion plate moves downwards and cannot continue to move downwards due to the support of the limiting block, at the moment, the clamping rack cannot continue to be in meshing transmission with the clamping gear due to the downward movement of the expansion plate, the expansion blocks at the left side and the right side are respectively pushed to extend out of the expansion cavity towards the left side and the right side by the thrust of the thrust spring, at the moment, the lifting block moves downwards to contact the contact switch, when the contact switch is contacted, the electromagnet does not adsorb any more, so that the bevel gear is pushed to move downwards to, thereby drive the axis of rotation through the meshing transmission this moment and rotate to drive the connecting block and rotate, thereby drive the expansion plate through the rotation of connecting block and rotate, thereby drive the expansion block rotation of left and right sides and enlarge the area of protection weight.

2. A firefighter lifesaving automatic protection method according to claim 1, further comprising the injured person protection step of: carry on the back injured person and place the decline piece up end at the back of the body case, personnel's weight can drive decline piece downstream to decline rack intracavity this moment, thereby the downstream through the decline piece drives decline rack downstream and drives right side gear shaft rotation with right side gear engagement transmission, thereby the rotation through the right side gear shaft drives left side gear shaft rotation through the transmission of drive belt, thereby the rotation through left side gear shaft drives left side gear shaft rotation, thereby the rotation through left side gear shaft drives ascending rack rebound through the meshing transmission, thereby it supports injured person as the back to drive ascending piece rebound to injured person's rear side.

3. A firefighter lifesaving automatic protection method according to claim 2, wherein a seat plate is fixedly connected to the bottom end of the left end surface of the back box, a descending rack cavity with an upward opening is arranged in the seat plate, a descending block is slidably connected to the front and rear walls of the descending rack cavity up and down, an ascending cavity with an upward opening is arranged on the left side of the descending rack cavity, and an ascending block is slidably connected to the front and rear walls of the ascending cavity up and down.

4. A firefighter survival automation protection method in accordance with claim 2, wherein the injured person protection step further comprises: when the piece that rises upwards moves to injured person's rear side and supports injured person as the back, when the piece that rises upwards moves to the bedplate upside, both sides baffle bottom overturns right around the baffle torsional spring can drive through the torsional spring power to prevent that injured person from falling down to both sides around.

5. The automatic protection method for firefighter lifesaving according to claim 4, wherein the transmission belt is located in a transmission belt cavity, the left end of the front wall and the left end of the rear wall of the transmission belt cavity are rotatably connected with a left gear shaft, the outer circular surface of the left gear shaft is fixedly connected with a left gear capable of being meshed with the ascending rack for transmission, the front side end surface and the rear side end surface of the ascending block are respectively rotatably connected with a baffle, and a baffle torsion spring is fixedly arranged at the joint of the baffle and the ascending block.

6. A firefighter lifesaving automatic protection method according to claim 1, wherein in the dense smoke elimination step, a fan cover is arranged outside the fan, the fan cover is fixed on the right end face of the back box, a fan cavity is arranged in the fan cover, and a fan shaft extends rightwards into the fan cavity, and the outer circumferential face of one side positioned in the fan cavity is fixedly connected with the fan.

7. A firefighter lifesaving automatic protection method according to claim 6, wherein the left and right walls of the transmission chamber are slidably connected with an adjusting block up and down, the upper end surface of the adjusting block is rotatably connected with a rotating shaft fixedly connected with the lower end surface of the connecting block, the outer circular surface key of the rotating shaft is connected with a switching bevel gear, and the upper end of the left wall of the transmission chamber is rotatably connected with a fan shaft extending to the right side of the back box.

8. A firefighter lifesaving automatic protection method according to claim 1, further comprising an auxiliary supporting step of: can drive bevel gear axle through two-way motor and rotate when fire fighter's physical power is not enough for thereby the contact of gyro wheel and ground is assisted fire fighter's removal.

9. A firefighter survival automation protection method as claimed in claim 8, wherein the auxiliary support step specifically includes: the bidirectional motor drives the bevel gear shaft to rotate, so that the bevel gear pair is driven to start meshing transmission, the lifting screw is driven to rotate, the threaded connection block is driven to move downwards through the rotation of the lifting screw, the button is pressed by the end face under the threaded connection block, then the rotation of the bevel gear shaft is stopped through the bidirectional motor, and the movement of a fireman is assisted through the contact of the roller and the ground.

10. A firefighter survival automatic protection method according to claims 1-9, wherein the smoke abatement step is preceded by: the firefighter backs up the back of the body case from the right side of the back of the body case to thereby drive adjusting screw through rotating the handle and rotate, thereby drive the regulating block through threaded connection and upwards or remove downwards, thereby adjust the position of expansion plate through the connection of axis of rotation.

Technical Field

The invention relates to the field of fire protection and lifesaving, in particular to an automatic lifesaving protection method for firefighters.

Background

In various conflagrations, because accident site environment's complexity, by the thing that falls, dense smoke etc. cause the injured accident of fire fighter very much, cause personnel's damage very easily, and when rescuing injured personnel, need fire fighter's both hands to carry out the bearing to personnel, not only very big consumption fire fighter's physical power, the inconvenience of fire fighter action has still been caused simultaneously, consequently prior art is difficult to fine plays the additional work to fire fighter, and the auxiliary effect is not good, need to wait for the improvement urgently.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides an automatic protection method for firefighters in order to overcome the technical defects that the prior art is difficult to well assist the firefighters and the assisting effect is poor.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: an automatic protection method for firefighter lifesaving, comprising the following steps:

dense smoke elimination step: when entering a fire scene, the bidirectional motor is started to drive the fan shaft to rotate, and the fan is driven to rotate to generate wind power rightwards through the rotation of the fan shaft, so that the interference of dense smoke on firemen is reduced;

a step of stopping falling objects: if an object falls from the upper part, the falling object firstly falls on the upper end surface of the expansion plate, when the object is heavier, the expansion plate is pressed downwards to drive the lifting block to move downwards, at the moment, the expansion spring is tightened, meanwhile, the fixed rack block can extend upwards and penetrate through the abdicating cavity to extend upwards to the upper side of the expansion plate, at the moment, the expansion plate moves downwards and cannot continue to move downwards due to the support of the limiting block, at the moment, the clamping rack cannot continue to be in meshing transmission with the clamping gear due to the downward movement of the expansion plate, the expansion blocks at the left side and the right side are respectively pushed to extend out of the expansion cavity towards the left side and the right side by the thrust of the thrust spring, at the moment, the lifting block moves downwards to contact the contact switch, when the contact switch is contacted, the electromagnet does not adsorb any more, so that the bevel gear is pushed to move downwards to, thereby drive the axis of rotation through the meshing transmission this moment and rotate to drive the connecting block and rotate, thereby drive the expansion plate through the rotation of connecting block and rotate, thereby drive the expansion block rotation of left and right sides and enlarge the area of protection weight.

Preferably, the method further comprises the following steps of: carry on the back injured person and place the decline piece up end at the back of the body case, personnel's weight can drive decline piece downstream to decline rack intracavity this moment, thereby the downstream through the decline piece drives decline rack downstream and drives right side gear shaft rotation with right side gear engagement transmission, thereby the rotation through the right side gear shaft drives left side gear shaft rotation through the transmission of drive belt, thereby the rotation through left side gear shaft drives left side gear shaft rotation, thereby the rotation through left side gear shaft drives ascending rack rebound through the meshing transmission, thereby it supports injured person as the back to drive ascending piece rebound to injured person's rear side.

Preferably, the bottom end of the left end face of the back box is fixedly connected with a seat plate, a descending rack cavity with an upward opening is arranged in the seat plate, a descending block is connected to the front wall and the rear wall of the descending rack cavity in a vertical sliding mode, an ascending cavity with an upward opening is arranged on the left side of the descending rack cavity, and an ascending block is connected to the front wall and the rear wall of the ascending cavity in a vertical sliding mode.

Preferably, the injured person protecting step further comprises: when the piece that rises upwards moves to injured person's rear side and supports injured person as the back, when the piece that rises upwards moves to the bedplate upside, both sides baffle bottom overturns right around the baffle torsional spring can drive through the torsional spring power to prevent that injured person from falling down to both sides around.

Preferably, the drive belt is located the drive belt chamber, and the wall left end rotates before the drive belt chamber and is connected with the left side gear shaft, and the outer disc fixedly connected with of left side gear shaft can with the driven left side gear of ascending rack toothing, and both sides terminal surface all rotates around the piece that rises and is connected with the baffle, and the baffle is fixed with the baffle torsional spring with the articulated department that rises the piece.

Preferably, a fan cover is arranged outside the fan in the dense smoke eliminating step, the fan cover is fixed on the right end face of the back box, a fan cavity is formed in the fan cover, and a fan shaft extends rightwards into the fan cavity and is fixedly connected with the outer circular face of one side in the fan cavity.

Preferably, the upper and lower sliding connection of the left and right walls of the transmission cavity has an adjusting block, the upper end surface of the adjusting block is rotatably connected with a rotating shaft fixedly connected with the lower end surface of the connecting block, the outer circular surface key of the rotating shaft is connected with a switching bevel gear, and the upper end of the left wall of the transmission cavity is rotatably connected with a fan shaft extending rightwards to the right side of the back box.

Preferably, the method further comprises the auxiliary supporting step: can drive bevel gear axle through two-way motor and rotate when fire fighter's physical power is not enough for thereby the contact of gyro wheel and ground is assisted fire fighter's removal.

Preferably, the auxiliary supporting step specifically includes: the bidirectional motor drives the bevel gear shaft to rotate, so that the bevel gear pair is driven to start meshing transmission, the lifting screw is driven to rotate, the threaded connection block is driven to move downwards through the rotation of the lifting screw, the button is pressed by the end face under the threaded connection block, then the rotation of the bevel gear shaft is stopped through the bidirectional motor, and the movement of a fireman is assisted through the contact of the roller and the ground.

Preferably, the smoke abatement step is preceded by: the firefighter backs up the back of the body case from the right side of the back of the body case to thereby drive adjusting screw through rotating the handle and rotate, thereby drive the regulating block through threaded connection and upwards or remove downwards, thereby adjust the position of expansion plate through the connection of axis of rotation.

(III) advantageous effects

When an object above a fireman falls, the telescopic block can be triggered to push the telescopic block to pop out, and the whole telescopic plate is driven to rotate, so that the object above the fireman is blocked.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is an enlarged schematic view of A in FIG. 1;

FIG. 3 is an enlarged schematic view of B of FIG. 1;

FIG. 4 is an enlarged schematic view of C in FIG. 1;

FIG. 5 is an enlarged schematic view of D of FIG. 1;

FIG. 6 is an enlarged schematic view of E-E of FIG. 5;

fig. 7 is a schematic diagram of a method of an embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 6, the automatic protection device for firefighter lifesaving of this embodiment includes a back box 11, a transmission cavity 12 with an upward opening is provided in the back box 11, a connecting block 13 extending upward to the upper side of the back box 11 is slidably connected to the front and rear walls of the transmission cavity 12 up and down, a button cavity 23 with an upward opening is provided in the connecting block 13, a lifting block 27 is slidably connected to the front and rear walls of the button cavity 23 up and down, an expansion plate 31 is fixedly connected to the upper end surface of the lifting block 27, a winding wheel cavity 37 is provided in the expansion plate 31, expansion cavities 32 with symmetrical opening toward the left and right sides are provided on the left and right sides of the winding wheel cavity 37, expansion blocks 33 are slidably connected to the front and rear walls of the expansion cavities 32 left and right, a communicating cavity 36 is respectively communicated between a side wall of the expansion cavities 32 on the left and right sides adjacent to each other and the left and right side walls of the winding wheel cavity, an expansion spring 24 is fixedly connected between the lower end surface of the lifting block 27 and the lower wall of the button cavity 23, a contact switch 26 is fixedly arranged on the right wall of the button cavity 23, and a clamping rack 42 is fixedly connected to the upper end of the right end surface of the fixed rack block 25. A winding wheel shaft 41 is rotatably connected with the front and rear walls of the winding wheel cavity 37, a clamping gear 40 which can be meshed with the clamping rack 42 for transmission is fixedly connected with the outer circular surface of the winding wheel shaft 41, a winding wheel 39 which is positioned at the rear side of the clamping gear 40 is fixedly connected with the outer circular surface of the winding wheel 39, a pull rope 35 which is fixedly connected with one side end surface close to the left and right expansion blocks 33 is wound and accommodated in the outer circular surface of the winding wheel 39, the pull rope 35 penetrates through the communicating cavity 36, a thrust spring 34 is fixedly connected between one side end surface close to the left and right expansion blocks 33 and one side wall close to the left and right expansion cavities 32, the winding wheel cavity 37 is provided with a yielding cavity 38 with an upward opening in a communicating way, the left end of the upper wall of the connecting block 13 is hinged with a limiting block 28, a limiting torsion spring 29 is fixedly arranged at the hinged part of the limiting block 28 and the connecting block 13, a clutch spring 54 is fixedly connected between the upper end surface of the switching bevel gear 51 and the lower end surface of the connecting block 13, the lower side of the back box 11 is rotatably connected with an adjusting screw 16 which extends upwards into the transmission cavity 12, the lower end surface of the adjusting screw 16 is fixedly connected with a handle 17, and the adjusting screw 16 extends upwards into the adjusting block 15 and is in threaded connection with the adjusting block 15.

The left wall and the right wall of the transmission cavity 12 are vertically and slidably connected with an adjusting block 15, the upper end face of the adjusting block 15 is rotatably connected with a rotating shaft 14 fixedly connected with the lower end face of the connecting block 13, the outer circular face of the rotating shaft 14 is connected with a switching bevel gear 51 in a key mode, the upper end of the left wall of the transmission cavity 12 is rotatably connected with a fan shaft 46 extending rightwards to the right side of the back box 11, the left side of the transmission cavity 12 is provided with a bevel gear cavity 18 with a downward opening, the front wall and the rear wall of the bevel gear cavity 18 are vertically and slidably connected with a threaded connecting block 20 extending downwards to the lower side of the back box 11, the lower side of the threaded connecting block 20 is provided with a roller block 67, a spring cavity 68 with an upward opening is arranged in the roller block 67, the threaded connecting block 20 extends downwards into the spring cavity 68 and is vertically and slidably connected with the spring cavity 68, the front wall and the rear wall of the descending rack cavity 21 are connected with a descending block 22 in a vertical sliding mode, the left side of the descending rack cavity 21 is provided with an ascending cavity 62 with an upward opening, the front wall and the rear wall of the ascending cavity 62 are connected with an ascending block 63 in a vertical sliding mode, and a transmission belt cavity 56 is communicated between the right wall of the ascending cavity 62 and the left wall of the descending rack cavity 21. Descending rack 55 is fixedly connected to the left end face of descending block 22, ascending rack 64 is fixedly connected to the right end face of ascending block 63, right end face of front and back wall of transmission belt cavity 56 is rotatably connected with right gear shaft 58, right gear shaft 58 outer circular face is fixedly connected with right gear 59 capable of being meshed with descending rack 55 for transmission, left gear shaft 61 is rotatably connected to left end of front and back wall of transmission belt cavity 56, left gear shaft 61 outer circular face is fixedly connected with left gear 60 capable of being meshed with ascending rack 64 for transmission, transmission belt 57 located in front of right gear 59 and left gear 60 is dynamically connected between left gear shaft 61 and right gear shaft 58, baffle 65 is rotatably connected to front and back side end faces of ascending block 63, and baffle 66 is fixedly arranged at the hinged position of baffle 65 and ascending block 63.

The left wall of the transmission cavity 12 is fixedly provided with a bidirectional motor 45, the right end face of the bidirectional motor 45 is in power connection with the left end face of a fan shaft 46, one outer circular face of one side of the fan shaft 46, which is positioned in the transmission cavity 12, is fixedly connected with a fan bevel gear 47 capable of being in meshing transmission with a switching bevel gear 51, the right end face of the back box 11 is fixedly connected with a fan cover 49, a fan cavity 50 is formed in the fan cover 49, and the fan shaft 46 extends rightwards into the fan cavity 50 and is positioned in the outer circular face of one side of the fan cavity 50 and is fixedly connected with a. The left end face of the bidirectional motor 45 is in power connection with a bevel gear shaft 44 which extends leftwards into the bevel gear cavity 18 and is rotatably connected with the left wall of the bevel gear cavity 18, the bidirectional motor 45 can be two motors which are independent from left to right or one motor which can independently output leftwards and rightwards, left power and right power can be output, the lower side of the bevel gear shaft 44 is provided with a lifting screw 19 which extends downwards into the internal thread cavity 73 and is in threaded connection with the internal thread cavity 73, the top end of the outer circular face of the lifting screw 19 and the outer circular face of the bevel gear shaft 44 are fixedly connected with a bevel gear pair 43 which is meshed with each other, a button spring 69 is fixedly connected between the lower wall of the spring cavity 68 and the lower end face of the threaded connection block 20, a button 70 which is positioned on the right side of the button spring 69 is fixedly arranged on the lower wall of the spring cavity 68, the end faces on the front side and.

In the initial state: the electromagnet 52 and the magnet 53 are in an adsorption and attachment state to drive the switching bevel gear 51 and the fan bevel gear 47 to be in a separation state, the telescopic spring 24 pushes the lifting block 27 to be located at an upper limit position, the clamping rack 42 is meshed with the clamping gear 40 to fix the winding wheel shaft 41, the thrust spring 34 is in a tightening state, the limiting torsion spring 29 is in a loosening state to drive the limiting block 28 to be in a vertical state, the button spring 69 is in a loosening state, the descending block 22 is located at an upper limit state, the ascending block 63 is located at a lower limit state, the baffle 65 is limited to the ascending cavity 62, and the baffle torsion spring 66 is in a tightening state.

The during operation, combine figure 7, the firefighter is from the right side of back of the body case 11 with back of the body case 11 back of the body, thereby drive adjusting screw 16 through rotating handle 17 and rotate, thereby drive regulating block 15 through threaded connection and upwards or move down, thereby the position of connection adjustment expansion plate 31 through axis of rotation 14, thereby start two-way motor 45 and drive fan shaft 46 and rotate when getting into the scene of a fire, the rotation through fan shaft 46 drives the rotatory wind power of producing of fan 48 right, thereby reduce dense cigarette to the interference of firefighter, carry out dense cigarette elimination step promptly. At this time, if an object falls from the upper side, the object can firstly fall on the upper end surface of the expansion plate 31, at this time, when the object is heavy, the expansion plate 31 is pressed downwards to drive the lifting block 27 to move downwards, at this time, the expansion spring 24 is tightened, the fixed rack block 25 can extend upwards and penetrate through the abdicating cavity 38 to extend upwards to the upper side of the expansion plate 31, at this time, the expansion plate 31 moves downwards and cannot continue to move downwards due to the support of the limit block 28, at this time, the expansion plate 31 moves downwards to drive the clamping rack 42 to not continue to be meshed with the clamping gear 40 for transmission, the left and right expansion blocks 33 are pushed to extend out of the expansion cavity 32 towards the left and right sides respectively by the thrust of the thrust spring 34, at this time, the lifting block 27 moves downwards to contact with the contact switch 26, when the contact switch 26 is contacted, the electromagnet 52 does not adsorb the magnetic block 53 any more, so that the bevel gear 51 is pushed by the thrust of the, thereby drive axis of rotation 14 through the meshing transmission this moment and rotate to drive connecting block 13 and rotate, thereby drive expansion plate 31 through the rotation of connecting block 13 and rotate, thereby drive the flexible piece 33 of left and right sides and rotate the area that enlarges the protection and weigh down the thing, accomplish and weigh down the thing and block the step. Protecting injured people: the injured person is carried and placed on the upper end surface of the descending block 22, at this time, the weight of the person drives the descending block 22 to move downwards to the descending rack cavity 21, the descending rack 55 is driven to move downwards by the downward movement of the descending block 22 and is meshed with the right gear 59 to drive the right gear shaft 58 to rotate, the left gear shaft 61 is driven to rotate by the transmission of the transmission belt 57 by the rotation of the right gear shaft 58, the left gear shaft 61 is driven to rotate by the rotation of the left gear shaft 61, the ascending rack 64 is driven to move upwards by the rotation of the left gear shaft 61 by the meshed transmission to drive the ascending block 63 to move upwards to the rear side of the injured person to be used as a backrest to support the injured person, and when the ascending block 63 moves upwards to the upper side of the seat plate 74, the baffle torsion spring 66 can drive the bottom ends of the front and rear side baffles, thereby preventing the injured person from falling down to the front and back sides. Auxiliary supporting: can drive bevel gear axle 44 through two-way motor 45 and rotate when fire fighter's physical power is not enough to drive bevel gear pair 43 and begin the meshing transmission, thereby drive lifting screw 19 and rotate, thereby it drives threaded connection piece 20 downstream to pass through threaded connection through lifting screw 19's rotation, thereby the terminal surface stops the rotation of bevel gear axle 44 through two-way motor 45 after pressing button 70 under threaded connection piece 20, thereby it is supplementary to fire fighter's removal through the contact of gyro wheel 72 with ground.

To sum up, when this embodiment has the object to fall in firefighter's top, can trigger the spring and promote flexible piece and pop out to drive whole expansion plate and rotate, thereby block the thing that falls of top for the firefighter, can stretch out back and baffle automatically when rescuing injured personnel simultaneously and protect, thereby prevent that the accident of injured personnel from dropping and causing secondary damage, and can make things convenient for firefighter's action.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.