阅读说明：本技术 一种具有定量输出机构的混凝土配比装置 (Concrete proportioning device with quantitative output mechanism ) 是由 王文磊 于 2021-08-06 设计创作，主要内容包括：本发明涉及混凝土配比混合设备技术领域,具体为一种具有定量输出机构的混凝土配比装置,包括搅拌组件,所述搅拌组件的上方设置有供料组件,所述供料组件包括支撑架,所述支撑架的上方固定连接有储料斗,所述储料斗的下方固定连接有计量斗；输送组件,所述输送组件设置在搅拌组件与计量斗之间,所述输送组件包括转动环,所述转动环的内部固定连接有供料盘,所述供料盘的下方设置有驱动组件。本发明能够有效的实现多种物料的输送混合配比,能够在多种物料输送的同时,通过旋转式供料,使得物料依次进行堆叠,从而使得物料进行充分混合,配比效率更高,大大降低了后续的工作时长,提高了整体工作效率。(The invention relates to the technical field of concrete proportioning and mixing equipment, in particular to a concrete proportioning device with a quantitative output mechanism, which comprises a stirring assembly, wherein a feeding assembly is arranged above the stirring assembly, the feeding assembly comprises a supporting frame, a storage hopper is fixedly connected above the supporting frame, and a metering hopper is fixedly connected below the storage hopper; the conveying assembly is arranged between the stirring assembly and the metering hopper and comprises a rotating ring, a feeding disc is fixedly connected inside the rotating ring, and a driving assembly is arranged below the feeding disc. The rotary type material mixing device can effectively realize conveying, mixing and proportioning of various materials, and can stack the materials in sequence through rotary type feeding while conveying the various materials, so that the materials are fully mixed, the proportioning efficiency is higher, the subsequent working time is greatly reduced, and the overall working efficiency is improved.)

1. The utility model provides a concrete proportioning device with ration output mechanism which characterized in that includes:

the stirring device comprises a stirring assembly (1), wherein a feeding assembly (2) is arranged above the stirring assembly (1), the feeding assembly (2) comprises a support frame (21), a storage hopper (22) is fixedly connected above the support frame (21), and a weighing hopper (23) is fixedly connected below the storage hopper (22);

conveying assembly (3), conveying assembly (3) set up between stirring subassembly (1) and weighing hopper (23), conveying assembly (3) include swivel becket (31), inside fixedly connected with feed tray (32) of swivel becket (31), the below of feed tray (32) is provided with drive assembly (33), the top of feed tray (32) is connected with conveying pipeline (34), the top of conveying pipeline (34) is connected with switching storage disk (35), the top of switching storage disk (35) is rotated and is connected with direction conveying board (38), the top fixedly connected with of direction conveying board (38) connects material pipe (36), the bulk material mouth has been seted up to the top of feed tray (32), and the below bulk material mouth edge of feed tray (32) is provided with switch-off plate (37).

2. A concrete proportioning device having a dosing output mechanism according to claim 1 wherein: stirring subassembly (1) includes landing leg (11), the top fixedly connected with motor (12) of landing leg (11), the output of motor (12) is connected with belt pulley drive mechanism (13), the other end of belt pulley drive mechanism (13) is connected with first reduction gear (14), the output of first reduction gear (14) is connected with second reduction gear (16) through universal joint (15), the output of second reduction gear (16) is connected with main shaft (17), the top fixedly connected with stirring rake (18) of main shaft (17), the top fixedly connected with agitator tank (19) of landing leg (11).

3. A concrete proportioning device having a dosing output mechanism according to claim 2 wherein: the utility model discloses a belt pulley drive mechanism, including landing leg (11), the horizontal pole top fixedly connected with backup pad of landing leg (11), and the top fixedly connected with motor (12) of backup pad, the outside of belt pulley drive mechanism (13) is provided with the guard plate, main shaft (17) run through the bottom center of agitator tank (19) to the top of mounting panel (331), the outer wall of agitator tank (19) is provided with the discharge gate.

4. A concrete proportioning device having a dosing output mechanism according to claim 1 wherein: support frame (21) pass through bolted connection in the top of agitator tank (19), support frame (21) and be provided with rubber gasket between agitator tank (19), the right angle department fixedly connected with triangle reinforcing plate of support frame (21), storage hopper (22) all are provided with four with weighing hopper (23), the below discharge gate fixedly connected with of weighing hopper (23) connects material pipe (36).

5. A concrete proportioning device having a dosing output mechanism according to claim 1 wherein: the rotating ring (31) is through bearing ring and agitator tank (19) to rotate and is connected, the lateral wall of rotating ring (31) is C shape structure, the inner wall fixedly connected with feed tray (32) of rotating ring (31), four bulk cargo mouths have been seted up to the top of feed tray (32), and the bulk cargo mouth is the slope form, the inner wall of feed tray (32) is C shape structure, and feed tray (32) are to rotate with mounting panel (331) and be connected.

6. A concrete proportioning device having a dosing output mechanism according to claim 5 wherein: the inside of feed dish (32) is provided with drive assembly (33), drive assembly (33) are including mounting panel (331), mounting panel (331) rotate the inner wall of connection in feed dish (32), the below fixedly connected with dead lever (332) of mounting panel (331), the top fixedly connected with commutator (333) of mounting panel (331), connecting axle (334) fixedly connected with rolling disc (335) is passed through to the top of commutator (333).

7. A concrete proportioning device having a dosing output mechanism according to claim 6 wherein: mounting panel (331) and agitator tank (19) top are in same water flat line, the both ends that dead lever (332) is all provided with the extension post, dead lever (332) one end extension post fixed connection is in the below of mounting panel (331), and other end extension post fixed connection is at the top lower surface of agitator tank (19), dead lever (332) are provided with four groups altogether, and dead lever (332) evenly distributed is at the bottom edge of mounting panel (331).

8. A concrete proportioning device having a dosing output mechanism according to claim 6 wherein: the central line of mounting panel (331) is run through main shaft (17), and the drive shaft interconnect of main shaft (17) and commutator (333), rolling disc (335) fixed connection is at the upper surface edge of feed dish (32), the below of rolling disc (335) is hollow structure, the top fixed connection of connecting axle (334) is at the inner wall of rolling disc (335), rolling disc (335) are in the below of switching storage disc (35).

9. A concrete proportioning device having a dosing output mechanism according to claim 1 wherein: conveying pipeline (34) are provided with four altogether, the one end fixed connection of conveying pipeline (34) is in the top that corresponds bulk cargo mouth feeding dish (32), the below in switching storage tray (35) is all connected to the other end of conveying pipeline (34), the below of switching storage tray (35) corresponds conveying pipeline (34) and is provided with four discharge gates, the inside fixedly connected with cross baffle of switching storage tray (35).

10. A concrete proportioning device having a dosing output mechanism according to claim 1 wherein: four discharge holes are formed in the upper portion of the guide material conveying plate (38), a material receiving pipe (36) is fixedly connected to the upper portion of each discharge hole, the outer wall of the guide material conveying plate (38) is rotatably connected with the transfer material storage disc (35) through a bearing ring, and the inner wall of the transfer material storage disc (35) is of a U-shaped structure corresponding to the position of the guide material conveying plate (38).

Technical Field

The invention relates to the technical field of concrete proportioning and mixing equipment, in particular to a concrete proportioning device with a quantitative output mechanism.

Background

A concrete proportioning device, also called proportioning and mixing equipment and an automatic sand and stone proportioning machine is an automatic device for quantitatively distributing various materials such as sand and stone, is mainly applied to the concrete construction industry, replaces modes such as a manual platform scale or volume metering, has the characteristics of high metering precision, high distribution efficiency, high automation degree and the like, is one of main parts in complete equipment of a full-automatic concrete mixing plant, can accurately realize the quantitative proportioning and mixing use of various materials, and greatly improves the working efficiency.

However, the in-process that current concrete proportioning device was using, although realized the accurate ration to the material, but when carrying out the transport ratio of material, still adopt the input of local material, and then realize the mode that relaxes through the mixer, realize the mixture of multiple material, the mode of this kind of pay-off still makes the material realize single region and deposits, it is obvious to make the multiple material differentiation after the pay-off, the hybrid of the material of being not convenient for is carried, thereby the mixing efficiency of material has been reduced, can't realize the flash mixed of material, thereby the work efficiency of follow-up material stirring mixture has been reduced, the operating time of increase material mixing stirring ratio has long, subsequent work efficiency has been reduced, consequently, need to design a concrete proportioning device with quantitative output mechanism to solve above-mentioned problem urgently.

Disclosure of Invention

The invention aims to provide a concrete proportioning device with a quantitative output mechanism, which aims to solve the problems that in the background art, a plurality of materials are obviously distinguished after being fed, and the materials are inconvenient to convey in a mixed mode, so that the mixing efficiency of the materials is reduced, and the materials cannot be quickly mixed.

In order to achieve the purpose, the invention provides the following technical scheme: a concrete proportioning device with a quantitative output mechanism, comprising:

the stirring device comprises a stirring assembly, a feeding assembly and a conveying assembly, wherein the feeding assembly is arranged above the stirring assembly and comprises a supporting frame, a storage hopper is fixedly connected above the supporting frame, and a weighing hopper is fixedly connected below the storage hopper;

the conveying assembly is arranged between the stirring assembly and the weighing hopper and comprises a rotating ring, a feed tray is fixedly connected to the inside of the rotating ring, a driving assembly is arranged below the feed tray, a feed conveying pipe is connected to the top of the feed tray, a transfer storage tray is connected to the top of the feed conveying pipe, a guide material conveying plate is connected to the top of the transfer storage tray in a rotating mode, a material receiving pipe is fixedly connected to the top of the guide material conveying plate, a material dispersing port is formed in the top of the feed tray, and a material stirring plate is arranged on the edge of a material dispersing port below the feed tray.

Preferably, the stirring subassembly includes the landing leg, the top fixedly connected with motor of landing leg, the output of motor is connected with belt pulley drive mechanism, belt pulley drive mechanism's the other end is connected with first reduction gear, the output of first reduction gear is connected with the second reduction gear through the universal joint, the output of second reduction gear is connected with the main shaft, the top fixedly connected with stirring rake of main shaft, the top fixedly connected with agitator tank of landing leg.

Preferably, the horizontal pole top fixedly connected with backup pad of landing leg, and the top fixedly connected with motor of backup pad, belt pulley drive mechanism's outside is provided with the guard plate, the main shaft runs through the bottom center of agitator tank to the top of mounting panel, the outer wall of agitator tank is provided with the discharge gate.

Preferably, the support frame passes through bolted connection in the top of agitator tank, the support frame with be provided with rubber shock absorber pad between the agitator tank, the right angle department fixedly connected with triangle reinforcing plate of support frame, storage hopper and weighing hopper all are provided with four, the below discharge gate fixedly connected with of weighing hopper connects the material pipe.

Preferably, the swivel becket is through bearing ring and agitator tank and rotates and be connected, the lateral wall of swivel becket is C shape structure, the inner wall fixedly connected with feed tray of swivel becket, four bulk cargo mouths have been seted up to the top of feed tray, and the bulk cargo mouth is the slope form, the inner wall of feed tray is C shape structure, and feed tray is to rotate with the mounting panel and be connected.

Preferably, the inside of feed dish is provided with drive assembly, drive assembly includes the mounting panel, the mounting panel rotates the inner wall of connection at the feed dish, the below fixedly connected with dead lever of mounting panel, the top fixedly connected with commutator of mounting panel, connecting axle fixedly connected with rolling disc is passed through to the top of commutator.

Preferably, the mounting panel is in same water flat line with the top of agitator tank, the both ends that the dead lever is all are provided with the extension post, dead lever one end extension post fixed connection is in the below of mounting panel, and other end extension post fixed connection is at the top lower surface of agitator tank, the dead lever is provided with four groups altogether, and dead lever evenly distributed is at the bottom edge of mounting panel.

Preferably, the main shaft penetrates through the center line of the mounting plate, the main shaft is connected with a driving shaft of the commutator, the rotating disc is fixedly connected to the edge of the upper surface of the feeding disc, the lower portion of the rotating disc is of a hollow structure, the upper portion of the connecting shaft is fixedly connected to the inner wall of the rotating disc, and the rotating disc is located below the material transferring storage disc.

Preferably, the conveying pipelines are four in number, one end of each conveying pipeline is fixedly connected above the corresponding material scattering port feeding disc, the other end of each conveying pipeline is connected below the switching storage disc, four discharge ports are formed in the lower portion of the switching storage disc corresponding to the conveying pipelines, and the switching storage disc is fixedly connected with a cross-shaped baffle.

Preferably, four discharge holes are formed in the upper portion of the guide material conveying plate, a material receiving pipe is fixedly connected to the upper portion of each discharge hole, the outer wall of the guide material conveying plate is rotatably connected with the transfer storage tray through a bearing ring, and the position, corresponding to the guide material conveying plate, of the inner wall of the transfer storage tray is of a U-shaped structure.

Compared with the prior art, the invention has the beneficial effects that: this concrete proportioning device can be effectual the transport of realizing multiple material mix the ratio, can be when multiple material is carried, through the rotation type feed for the material piles up in proper order, thereby makes the material carry out the intensive mixing, and proportioning efficiency is higher, greatly reduced subsequent during operation, improved whole work efficiency.

1. This concrete proportioning device with ration output mechanism realizes carrying out the rotation type feed to multiple material through adopting rotatory mode, can make the material pile up in proper order when rotating to make the multiple material of ratio can effectually mix, pile up the mixture in proper order through it, improved the mixing efficiency of multiple material, thereby it is long when having shortened the mixture of material, the effectual work efficiency who installs concrete material mixture ratio that has improved.

2. This concrete proportioning device with ration output mechanism realizes carrying out the rotation type feed to multiple material through adopting rotatory mode, can make the material when rotating, make the material pile up in proper order, thereby when carrying out the feed of multiple material, can effectually avoid the same kind of material to pile up together, when leading to follow-up working strength to increase, the transport of the material of being not convenient for, the piling up of material appears easily, the transport that leads to the material blocks up, and then through the rotation type feed, can be even carry out the feed to the agitator tank inside, the effectual intensive mixing who guarantees the material when guaranteeing the material to add evenly.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of the overall structure of the feeding assembly of the present invention;

FIG. 3 is a schematic view of the overall structure of the stirring assembly of the present invention;

FIG. 4 is a schematic view of the internal structure of the stirring tank of the present invention;

FIG. 5 is a schematic view of a driving structure of the stirring assembly of the present invention;

FIG. 6 is a schematic view of the connecting structure of the conveying assembly of the present invention;

FIG. 7 is a schematic view of a partial explosion of the transfer assembly of the present invention;

FIG. 8 is a schematic view of the overall structure of the feed tray of the present invention;

FIG. 9 is a schematic view of an explosive state structure of the transfer storage tray according to the present invention;

FIG. 10 is a schematic view of the exploded configuration of the paddle according to the present invention.

In the figure: 1. a stirring assembly; 11. a support leg; 12. a motor; 13. a belt pulley transmission mechanism; 14. a first decelerator; 15. a universal joint; 16. a second decelerator; 17. a main shaft; 18. a stirring paddle; 19. a stirring box; 2. a supply assembly; 21. a support frame; 22. a storage hopper; 23. a measuring hopper; 3. a delivery assembly; 31. a rotating ring; 32. a feeding tray; 33. a drive assembly; 331. mounting a plate; 332. fixing the rod; 333. a commutator; 334. a connecting shaft; 335. rotating the disc; 34. a delivery pipe; 35. transferring the material storage disc; 36. a material receiving pipe; 37. a kick-out plate; 38. and (5) guiding the material conveying plate.

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. 1-10, an embodiment of the present invention is shown:

a concrete proportioning device with a quantitative output mechanism, comprising:

the stirring assembly 1 is provided with a feeding assembly 2 above the stirring assembly 1, the feeding assembly 2 comprises a support frame 21, a storage hopper 22 is fixedly connected above the support frame 21, a metering hopper 23 is fixedly connected below the storage hopper 22, the metering hopper 23 comprises a weighing hopper, a suspension device, a weighing system sensor, a batching controller and the like, the stirring assembly has the characteristic of high metering precision, and is integrally used for providing materials for the stirring assembly 1;

conveying assembly 3, conveying assembly 3 sets up between stirring subassembly 1 and weighing hopper 23, conveying assembly 3 includes swivel 31, the inside fixedly connected with feed tray 32 of swivel 31, be provided with drive assembly 33 below feed tray 32, feed tray 32 is connected with conveying pipeline 34 in the top, conveying pipeline 34's top is connected with switching storage tray 35, switching storage tray 35's top is rotated and is connected with direction defeated flitch 38, direction defeated flitch 38's top fixedly connected with material receiving pipe 36, the bulk cargo mouth has been seted up above feed tray 32, and the below bulk cargo mouth edge of feed tray 32 is provided with switch-plate 37, through the setting of this structure, can realize carrying out rotatory stack formula feeding to the multiple material that adds, make the multiple material that adds can circulate the rotation and carry out the stack, guaranteed the intensive mixing of material, provide through main shaft 17 power, can realize the rotation to connecting axle 334 through the turning to commutator 333, further can drive rolling disc 335 and rotate to drive feed dish 32 and rotate, thereby through the rotation of feed dish 32, make the bulk material mouth of top present circular circulation rotation blanking when the blanking, guaranteed the flash mixed of material.

Further, the stirring component 1 comprises a supporting leg 11, a motor 12 is fixedly connected above the supporting leg 11, an output end of the motor 12 is connected with a belt pulley transmission mechanism 13, the other end of the belt pulley transmission mechanism 13 is connected with a first speed reducer 14, an output end of the first speed reducer 14 is connected with a second speed reducer 16 through a universal joint 15, an output end of the second speed reducer 16 is connected with a main shaft 17, a stirring paddle 18 is fixedly connected above the main shaft 17, a stirring box 19 is fixedly connected above the supporting leg 11, through the arrangement of the structure, the materials after proportioning can be mixed and stirred, the sufficient mixing of the materials is accelerated, the blanking of the subsequent work is reduced, through the work of the motor 12, the first speed reducer 14 can be driven to work through the belt pulley transmission mechanism 13, the universal joint 15 is further driven to rotate, and the second speed reducer 16 is further driven to work through the universal joint 15, thereby drive main shaft 17 and rotate, drive stirring rake 18 through main shaft 17 simultaneously and rotate, realize the stirring to the material for the stirring to the material is realized to the realization in the blanking of material, and the stirring direction is reverse with material blanking direction, has further improved the flash mixed stirring to the material.

Further, the horizontal pole top fixedly connected with backup pad of landing leg 11, and the top fixedly connected with motor 12 of backup pad, belt pulley drive 13's outside is provided with the guard plate for belt pulley drive 13's transmission protection, main shaft 17 runs through agitator tank 19's bottom center to the top of mounting panel 331, and agitator tank 19's outer wall is provided with the discharge gate for the discharge of stirring post-mixing material.

Further, support frame 21 passes through bolted connection in the top of agitator tank 19, support frame 21 with be provided with rubber gasket between agitator tank 19, the reduction plays the effect of buffering, the frictional production of noise reduction simultaneously, the triangle reinforcing plate of right angle department fixedly connected with of support frame 21 improves the stability of support frame 21, storage hopper 22 all is provided with four with weighing hopper 23, weighing hopper 23's below discharge gate fixedly connected with connects material pipe 36 for the interpolation guide of material.

Further, the swivel becket 31 is to rotate with agitator tank 19 through the bearing ring and is connected, the lateral wall of swivel becket 31 is C shape structure, the inner wall fixedly connected with feed tray 32 of swivel becket 31, four bulk cargo mouths have been seted up to feed tray 32's top, and the bulk cargo mouth is the slope form, feed tray 32's inner wall is C shape structure, and feed tray 32 is to rotate with mounting panel 331 and is connected, the setting of this structure, feed tray 32 and swivel becket 31 pivoted stability have been guaranteed, and frictional force is little, convenient drive, and then realize the circular trend blanking to the material through the rotation of bulk cargo mouth.

Further, the inside of feed dish 32 is provided with drive assembly 33, drive assembly 33 includes mounting panel 331, mounting panel 331 rotates the inner wall of connection at feed dish 32, mounting panel 331's below fixedly connected with dead lever 332, mounting panel 331's top fixedly connected with commutator 333, connecting axle 334 fixedly connected with rolling disc 335 is passed through to commutator 333's top, setting through this structure, a rotation drive for feed dish 32, rotation through main shaft 17, can drive commutator 333 and turn to the processing, further drive rolling disc 335 through connecting axle 334 and rotate, thereby can drive feed dish 32 and rotate.

Further, mounting panel 331 is in same water flat line with agitator tank 19's top, the both ends that dead lever 332 is all provided with the extension post, dead lever 332 one end extension post fixed connection is in mounting panel 331's below, and other end extension post fixed connection is at agitator tank 19's top lower surface, dead lever 332 is provided with four groups altogether, and dead lever 332 evenly distributed is at mounting panel 331's bottom edge, the setting of dead lever 332 is used for mounting panel 331's fixed use, guarantee mounting panel 331's stability, thereby be convenient for the installation of top commutator 333 fixed and to the further rotation support of feed tray 32, feed tray 32 pivoted stability has been guaranteed.

Furthermore, the main shaft 17 penetrates through the center line of the mounting plate 331, the main shaft 17 is connected with a driving shaft of the commutator 333, the rotating disc 335 is fixedly connected to the edge of the upper surface of the supply disc 32, the lower part of the rotating disc 335 is of a hollow structure, the upper part of the connecting shaft 334 is fixedly connected to the inner wall of the rotating disc 335, and the rotating disc 335 is located below the transfer storage disc 35 and is used for driving the supply disc 32 to rotate through the connection between the rotating disc 335 and the supply disc 32.

Further, conveying pipeline 34 is provided with four altogether, the one end fixed connection of conveying pipeline 34 is in the top that corresponds bulk cargo mouth feeding tray 32, the other end of conveying pipeline 34 all is connected in the below of switching storage tray 35, the below of switching storage tray 35 corresponds conveying pipeline 34 and is provided with four discharge gates, the inside fixedly connected with cross baffle of switching storage tray 35, a comfortable for the material, and through the setting of a plurality of conveying pipelines 34, can realize the circulation rotation unloading of material and handle, accelerate the mixture of material.

Further, four discharge openings have been seted up to the top of direction defeated flitch 38, and the top fixedly connected with material receiving pipe 36 of discharge opening, the outer wall of direction defeated flitch 38 is to rotate through bearing ring and switching storage tray 35 and is connected, and the position department that switching storage tray 35 inner wall corresponds direction defeated flitch 38 is the U-shaped structure, through the setting of this structure, can realize being connected the rotation of switching storage tray 35 and direction defeated flitch 38, guarantee switching storage tray 35 pivoted stability, direction defeated flitch 38 is in the below of weighing hopper 23 through material receiving pipe 36 fixed connection simultaneously.

The working principle is as follows: when the invention is used, a plurality of required materials are firstly added into the storage hopper 22, when concrete is required to be proportioned and mixed, the metering hopper 23 can realize the accurate quantitative control of the added materials, the conveyed materials are conveyed to the interior of the switching storage tray 35 through the material receiving pipe 36, meanwhile, the material transferring and storing disc 35 can be started by the motor 12 below, the belt pulley transmission mechanism 13 drives the first speed reducer 14 to work, the universal joint 15 further drives the second speed reducer 16 to act, the rotation of the spindle 17 is further realized, the spindle 17 can rotate and simultaneously rotate the connecting shaft 334 through the steering of the commutator 333, the rotation of the rotating disc 335 is further realized, thereby, the rotating disc 335 drives the feeding disc 32 to rotate, and the feeding disc 32 can drive the feeding pipe 34 and the transferring storage disc 35 above to rotate simultaneously.

And then in switching storage tray 35 pivoted, can realize carrying out material temporary storage to four material chambeies of inside, and can pass through conveying pipeline 34 with the material and carry to feed tray 32's inside in the pivoted, further rotation through feed tray 32 can carry out rotatory bulk cargo through the bulk cargo mouth with the material, thereby add the material to agitator tank 19's inside, and in feed tray 32 pivoted, the material drops the rotation in proper order when can, make the material that drops pile up in proper order, and then accelerated the mixture of material, drive stirring rake 18 through main shaft 17 simultaneously and rotate, realization that can be quick is to the hybrid processing of material, accelerate the flash mixed of material, improve device's work efficiency.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.