1. An adaptive package production apparatus comprising a support table, characterized in that: a tray mechanism is arranged on the upper side of the supporting table, a buffer board storage box is fixed on the left end face of the supporting table, and a speed regulating mechanism is arranged in the buffer board storage box;

the tray mechanism comprises an object stage arranged on the upper side of the support table, two conveying belt wheels arranged in a front mirror image mode and a rear mirror image mode are arranged in the object stage, and the tray mechanism is used for lifting a porcelain dish to be packaged;

the speed regulating mechanism comprises a conical friction wheel arranged in the buffer board storage box, a sliding friction wheel is arranged on the right side of the conical friction wheel, a driving bevel gear is arranged on the front side of the sliding friction wheel, a driven bevel gear is arranged on the right side of the driving bevel gear, and the speed regulating mechanism is used for regulating the number of the buffer foam boards conveyed in the same time.

2. An adaptive package producing apparatus according to claim 1, characterized in that: four guide rods arranged in a mirror image mode are fixed on the upper end face of the supporting table, a pair of sliding pairs is formed between each object stage and each guide rod, and a reset spring is fixed between the lower end face of each object stage and the upper end face of the supporting table.

3. An adaptive package producing apparatus according to claim 1, characterized in that: the tray mechanism is characterized by further comprising a conveying motor, a conveying belt wheel cavity which is communicated up and down is arranged in the objective table, the conveying motor is located on the left side of the conveying belt wheel cavity, two conveying belt wheel shafts which extend rightwards to penetrate through the conveying belt wheel cavity to the right end wall of the conveying belt wheel cavity and are symmetrical front and back are arranged in the conveying belt wheel cavity in a rotating fit mode on the left end face of the conveying belt wheel cavity, the left end face of each conveying belt wheel shaft is fixed on the right end face of the conveying motor, the conveying belt wheels are fixed on the conveying belt wheel shafts and located in the conveying belt wheel cavities, conveying belts are connected between the conveying belt wheels in a power fit mode on the front side and the rear side, and one-way friction blocks which are fixedly connected with the objective table and are arranged by taking the guide rods as center rings are arranged on the outer sides of the guide rods.

4. An adaptive package producing apparatus according to claim 3, characterized in that: the inner side surface of the one-way friction block is provided with an annular friction strip which inclines downwards, so that the friction force is small when the object stage moves downwards relative to the guide rod, and the friction force is large when the object stage moves upwards relative to the guide rod.

5. An adaptive package producing apparatus according to claim 1, characterized in that: the buffer board is equipped with buffer board storage chamber in the buffer board storage case, buffer board storage chamber right side intercommunication is equipped with opening right buffer board and carries the chamber, buffer board carries the chamber downside to be equipped with opening right objective table sliding chamber, objective table left side end with it is vice to form a pair of slip between the objective table sliding chamber, buffer board storage intracavity sliding fit has the buffer board backup pad, under the buffer board backup pad terminal surface with be fixed with supporting spring between the buffer board storage chamber lower end wall, buffer board storage chamber upside intercommunication is equipped with two bilateral symmetry's delivery wheel chamber, delivery wheel chamber front end wall internal rotation cooperation extends backward and runs through the delivery wheel chamber extremely delivery wheel axle in the delivery wheel chamber rear end wall, delivery wheel epaxial fixedly connected with is located delivery wheel in the delivery wheel chamber.

6. An adaptive package producing apparatus according to claim 5, characterized in that: the utility model discloses a buffer board storage box, including buffer board, conveying wheel chamber, bevel gear chamber, sliding friction wheel chamber, buffer board storage box, buffer board, and buffer board, and buffer board, and buffer board, and buffer board, and the buffer board, and board.

7. An adaptive package producing apparatus according to claim 1, characterized in that: the speed regulating mechanism further comprises a conveying motor shaft which is fixed on the rear end face of the conveying motor and extends backwards into the conical friction wheel cavity, the conveying wheel on the right side extends backwards into the bevel gear cavity, the driven bevel gear is fixed on the rear end of the conveying wheel shaft, a driving bevel gear shaft which extends through the sliding friction wheel cavity from the left side to the rear side to the inner side of the rear end wall of the sliding friction wheel cavity and extends from the right side to the inner side of the rear end wall of the bevel gear cavity is arranged on the upper end wall of the bevel gear cavity in a rotating fit mode, and the driving bevel gear is fixed on the front end of the driving bevel gear shaft and is meshed with the driven bevel gear.

8. An adaptive package producing apparatus according to claim 7, characterized in that: the driving bevel gear shaft is provided with a spline sleeve in a spline fit mode, the spline sleeve is located in the sliding friction wheel cavity, the sliding friction wheel is fixed at the tail end of the rear side of the spline sleeve and is abutted against the tapered friction wheel, the tail end of the front side of the spline sleeve is in a spline fit mode with a spline sleeve rotating seat in a rotating mode, a friction wheel spring is fixed between the front end face of the spline sleeve rotating seat and the front end wall of the sliding friction wheel cavity, a speed regulation pull rope is fixed on the front end face of the spline sleeve rotating seat, and the tapered friction wheel is fixed at the tail end of the rear side of the conveying motor shaft.

9. An adaptive package producing apparatus according to claim 1, characterized in that: the utility model discloses a slide switch, including objective table, speed governing stay cord, contact switch sliding cavity, speed governing stay cord, the rear side intercommunication of objective table sliding cavity is equipped with contact switch sliding cavity, contact switch sliding cavity sliding fit extends to forward contact switch in the objective table sliding cavity, contact switch sliding cavity end wall internal rotation fit has upwards to extend and runs through contact switch sliding cavity to external world and with the contact switch lead screw that screw-thread fit connects between the contact switch, contact switch lead screw upside end is fixed with the adjustment disk.

Background

The packing piece means the totality that the product formed after the packing, and the porcelain makes porcelain packing become a difficult problem because of its fragile nature for some porcelain dish porcelain bowl's packing can add one deck buffering cystosepiment between porcelain dish and porcelain dish, but because the packing of porcelain dish is placed, even there is the buffering of buffering cystosepiment, the porcelain dish of lower floor can very easily be cracked because of the extrusion of a plurality of porcelain dishes on the upper strata, thereby causes unnecessary loss.

Disclosure of Invention

The object of the present invention is to provide an adaptive package production device for overcoming the above-mentioned drawbacks of the prior art.

The self-adaptive packaging piece production equipment comprises a supporting table, wherein a tray mechanism is arranged on the upper side of the supporting table, a buffer board storage box is fixed on the left end face of the supporting table, and a speed regulating mechanism is arranged in the buffer board storage box;

the tray mechanism comprises an object stage arranged on the upper side of the support table, two conveying belt wheels arranged in a front mirror image mode and a rear mirror image mode are arranged in the object stage, and the tray mechanism is used for lifting a porcelain dish to be packaged;

the speed regulating mechanism comprises a conical friction wheel arranged in the buffer board storage box, a sliding friction wheel is arranged on the right side of the conical friction wheel, a driving bevel gear is arranged on the front side of the sliding friction wheel, a driven bevel gear is arranged on the right side of the driving bevel gear, and the speed regulating mechanism is used for regulating the number of the buffer foam boards conveyed in the same time.

According to the technical scheme, four guide rods arranged in a mirror image mode are fixed on the upper end face of the supporting table, a pair of sliding pairs is formed between each objective table and the corresponding guide rod, and a reset spring is fixed between the lower end face of each objective table and the upper end face of the supporting table.

According to the technical scheme, the tray mechanism further comprises a conveying motor, a conveying belt wheel cavity which is through up and down is arranged in the objective table, the conveying motor is located on the left side of the conveying belt wheel cavity, two conveying belt wheel shafts which extend rightwards to penetrate through the conveying belt wheel cavity to the right end wall of the conveying belt wheel cavity and are symmetrical front and back are arranged in the conveying belt wheel cavity in a rotating fit mode on the left end face of the conveying belt wheel cavity, the left end face of the conveying belt wheel shaft on the front side is fixed on the right end face of the conveying motor, the conveying belt wheels are fixed on the conveying belt wheel shaft and located in the conveying belt wheel cavity, conveying belts are connected between the conveying belt wheels on the front side and the rear side in a power fit mode, and one-way friction blocks which are fixedly connected with the objective table and are arranged with the guide rods as center rings are arranged on the outer sides of the guide rods.

According to the technical scheme, the inner side face of the one-way friction block is provided with an annular friction strip which inclines downwards, so that the friction force is small when the object stage moves downwards relative to the guide rod, and the friction force is large when the object stage moves upwards relative to the guide rod.

Further technical scheme, be equipped with buffer board storage chamber in the buffer board storage box, buffer board storage chamber right side intercommunication is equipped with opening right buffer board and carries the chamber, buffer board transport chamber downside is equipped with opening right objective table slip chamber, objective table left side end with form a pair of slip pair between the objective table slip chamber, buffer board storage intracavity sliding fit has the buffer board backup pad, under the buffer board backup pad terminal surface with be fixed with supporting spring between the buffer board storage chamber lower end wall, buffer board storage chamber upside intercommunication is equipped with the delivery wheel chamber of two bilateral symmetry, delivery wheel chamber front end wall cooperation extends backward and runs through the delivery wheel chamber extremely delivery wheel axle in the delivery wheel chamber rear end wall, delivery wheel epaxial fixedly connected with is located the delivery wheel of delivery wheel intracavity.

According to the technical scheme, a bevel gear cavity is formed in the rear side of the conveying wheel cavity, a sliding friction wheel cavity is formed in the rear side of the bevel gear cavity, a conical friction wheel cavity is formed in the left side of the sliding friction wheel cavity, and a conveying motor fixedly connected with the buffer board storage box is arranged on the front side of the conical friction wheel cavity.

According to the technical scheme, the speed regulating mechanism further comprises a conveying motor shaft which is fixed on the rear end face of the conveying motor and extends backwards into the conical friction wheel cavity, the conveying wheel on the right side extends backwards into the bevel gear cavity, the driven bevel gear is fixed on the tail end of the rear side of the conveying wheel shaft, a driving bevel gear shaft which extends through the sliding friction wheel cavity from the left rear side to the inner side of the rear end wall of the sliding friction wheel cavity to the right front side and extends into the bevel gear cavity is arranged on the upper end wall of the bevel gear cavity in a rotating fit mode, and the driving bevel gear is fixed on the tail end of the front side of the driving bevel gear shaft and is meshed with the driven bevel gear.

According to the technical scheme, a spline sleeve located in the sliding friction wheel cavity is matched with a spline on the driving bevel gear shaft, the sliding friction wheel is fixed at the tail end of the rear side of the spline sleeve and abutted against the tapered friction wheel, a spline sleeve rotating seat is matched with the tail end of the front side of the spline sleeve in a rotating mode, a friction wheel spring is fixed between the front end wall of the spline sleeve rotating seat and the front end wall of the sliding friction wheel cavity, a speed-regulating pull rope is fixed on the front end face of the spline sleeve rotating seat, and the tapered friction wheel is fixed at the tail end of the rear side of the conveying motor shaft.

Further technical scheme, the terminal surface internal fixation has motion sensor before the objective table, the speed governing stay cord is fixed in on the objective table up end, objective table slip chamber rear side intercommunication is equipped with contact switch sliding chamber, contact switch sliding chamber sliding fit is to extending forward to the contact switch of objective table slip intracavity, contact switch sliding chamber lower extreme wall internal rotation cooperation has upwards to extend and runs through contact switch sliding chamber to external and with the contact switch lead screw that screw-thread fit is connected between the contact switch, contact switch lead screw upside end is fixed with the adjustment disk.

The invention has the beneficial effects that: when the porcelain dish was placed on the objective table, make the height of a porcelain dish of objective table decline under the action of gravity of porcelain dish, thereby make follow-up porcelain dish can pile up smoothly to first porcelain dish on, the transport shaft rotates simultaneously and makes the cystosepiment of buffer board storage intracavity move right to the porcelain dish on, and every pile of one deck porcelain dish, the rotational speed increase of transport shaft is a bit, the cystosepiment of carrying out in the buffer board storage intracavity is just more one, thereby realized piling up along with the porcelain dish, cystosepiment between porcelain dish and the porcelain dish increases gradually, thereby make to pile up the porcelain dish of accomplishing and fall the back, there is sufficient buffer board between the porcelain dish of lower floor and the upper porcelain dish, thereby avoid the extrusion of upper porcelain dish to make the porcelain dish of lower floor cracked.

Drawings

Fig. 1 is a schematic external view of an adaptive package producing apparatus of the present invention;

fig. 2 is a schematic view of the internal overall structure of an adaptive package producing apparatus of the present invention;

FIG. 3 is a schematic view of A-A of FIG. 2 in accordance with the present invention;

FIG. 4 is a schematic view of B-B of FIG. 2 according to the present invention;

FIG. 5 is a schematic view of C-C of FIG. 2 in accordance with the present invention;

FIG. 6 is an enlarged partial schematic view of the invention at D in FIG. 3;

FIG. 7 is a schematic view of E-E of FIG. 5 in accordance with the present invention.

Detailed Description

For purposes of making the objects and advantages of the present invention more apparent, the following detailed description of the invention, taken in conjunction with the examples, should be understood that the following text is only intended to describe an adaptive package production apparatus or several specific embodiments of the invention, and not to strictly limit the scope of the invention as specifically claimed, as used herein, the terms upper, lower, left and right are not limited to their strict geometric definition, but rather include tolerances for machining or human error rationality and inconsistencies, the specific features of which are set forth in detail below:

referring to fig. 1-7, the self-adaptive package production equipment according to the embodiment of the invention comprises a supporting table 10, wherein a tray mechanism is arranged on the upper side of the supporting table 10, a buffer board storage box 30 is fixed on the left end face of the supporting table 10, and a speed regulating mechanism is arranged in the buffer board storage box 30;

the tray mechanism comprises an object stage 20 arranged on the upper side of the support table 10, two conveying belt wheels 21 arranged in a front mirror image mode and a rear mirror image mode are arranged in the object stage 20, and the tray mechanism is used for lifting a porcelain dish to be packaged;

the speed regulating mechanism comprises a conical friction wheel 50 arranged in the buffer board storage box 30, a sliding friction wheel 51 is arranged on the right side of the conical friction wheel 50, a driving bevel gear 56 is arranged on the front side of the sliding friction wheel 51, a driven bevel gear 54 is arranged on the right side of the driving bevel gear 56, and the speed regulating mechanism is used for regulating the number of buffer foam boards conveyed in the same time.

Illustratively, four guide rods 12 arranged in a mirror image manner are fixed on the upper end surface of the support table 10, a pair of sliding pairs is formed between each of the four object stages 20 and the guide rods 12, and a return spring 11 is fixed between the lower end surface of the object stage 20 and the upper end surface of the support table 10.

Exemplarily, the tray mechanism further includes a conveying motor 24, a conveying pulley cavity 25 penetrating up and down is arranged in the objective table 20, the conveying motor 24 is located on the left side of the conveying pulley cavity 25, two conveying pulley shafts 23 extending rightward to penetrate through the conveying pulley cavity 25 to the inner side of the right end wall of the conveying pulley cavity 25 and symmetrical front and back are rotationally matched in the left end surface of the conveying pulley cavity 25, the left end surface of the conveying pulley shaft 23 on the front side is fixed on the right end surface of the conveying motor 24, the conveying pulley 21 is fixed on the conveying pulley shaft 23 and located in the conveying pulley cavity 25, a conveying belt 22 is connected between the conveying pulley shafts 21 on the front and back sides in a power fit manner, and a one-way friction block 28 fixedly connected with the objective table 20 and annularly arranged by taking the guide rod 12 as a center is arranged on the outer side of the guide rod 12.

Illustratively, the one-way friction block 28 has a downward annular friction strip on its inner side surface, so that the friction force is small when the object stage 20 moves downward relative to the guide bar 12, and the friction force is large when the object stage 20 moves upward relative to the guide bar 12.

Illustratively, a buffer board storage chamber 34 is provided in the buffer board storage box 30, a buffer board delivery chamber 38 with a rightward opening is provided in communication with the right side of the buffer board storage chamber 34, a stage sliding cavity 39 with a right opening is arranged at the lower side of the buffer plate conveying cavity 38, a pair of sliding pairs is formed between the tail end at the left side of the stage 20 and the stage sliding cavity 39, a buffer plate supporting plate 31 is in sliding fit in the buffer plate storage cavity 34, a supporting spring 32 is fixed between the lower end face of the buffer plate supporting plate 31 and the lower end wall of the buffer plate storage cavity 34, two bilaterally symmetrical conveying wheel cavities 37 are communicated and arranged on the upper side of the buffer plate storage cavity 34, a conveying wheel shaft 35 which extends backwards through the conveying wheel cavities 37 to the rear end wall of the conveying wheel cavity 37 is rotationally matched with the front end wall of the conveying wheel cavity 37, a conveying wheel 36 positioned in the conveying wheel cavity 37 is fixedly connected to the conveying wheel shaft 35.

Illustratively, a bevel gear cavity 15 is arranged at the rear side of the conveying wheel cavity 37, a sliding friction wheel cavity 14 is arranged at the rear side of the bevel gear cavity 15, a tapered friction wheel cavity 13 is arranged at the left side of the sliding friction wheel cavity 14, and a conveying motor 57 fixedly connected with the buffer board storage box 30 is arranged at the front side of the tapered friction wheel cavity 13.

Illustratively, the speed adjusting mechanism further comprises a conveying motor shaft 58 fixed on the rear end face of the conveying motor 57 and extending backwards into the bevel friction wheel cavity 13, the right side conveying wheel shaft 35 extends backwards into the bevel gear cavity 15, the driven bevel gear 54 is fixed on the rear end of the conveying wheel shaft 35, a driving bevel gear shaft 55 extending leftwards and rearwards through the sliding friction wheel cavity 14 to the rear end wall of the sliding friction wheel cavity 14 and extending rightwards and forwards into the bevel gear cavity 15 is rotationally matched on the upper end wall of the bevel gear cavity 15, and the driving bevel gear 56 is fixed on the front end of the driving bevel gear shaft 55 and meshed with the driven bevel gear 54.

Illustratively, a spline housing 52 located in the sliding friction wheel cavity 14 is spline-fitted on the driving bevel gear shaft 55, the sliding friction wheel 51 is fixed at the rear end of the spline housing 52 and abuts against the tapered friction wheel 50, a spline housing rotating seat 53 is rotationally fitted at the front end of the spline housing 52, a friction wheel spring 59 is fixed between the front end surface of the spline housing rotating seat 53 and the front end wall of the sliding friction wheel cavity 14, a speed regulating pull rope 27 is fixed at the front end surface of the spline housing rotating seat 53, and the tapered friction wheel 50 is fixed at the rear end of the conveying motor shaft 58.

Exemplarily, a motion sensor 26 is fixed in the front end face of the object stage 20, the speed-adjusting pull rope 27 is fixed on the upper end face of the object stage 20, a contact switch sliding cavity 43 is communicated with the rear side of the object stage sliding cavity 39, a contact switch 40 which extends forward into the object stage sliding cavity 39 is in sliding fit in the contact switch sliding cavity 43, a contact switch lead screw 42 which extends upward through the contact switch sliding cavity 43 to the outside and is in threaded fit connection with the contact switch 40 is in rotating fit in the lower end wall of the contact switch sliding cavity 43, and an adjusting plate 41 is fixed at the tail end of the upper side of the contact switch lead screw 42.

Under the initial condition, buffer board backup pad 31 is close to buffer board storage chamber 34 lower endwall, supporting spring 32 is in compression state, a plurality of soft buffering cystosepiments have been placed to buffer board backup pad 31 upside, the superiors 'cystosepiment abuts with delivery wheel 36 under supporting spring 32's spring action, objective table 20 up end and objective table slip chamber 39 upper endwall laminating, reset spring 11 is in compression state, speed governing stay cord 27 is in the state of tightening, slip friction pulley 51 and the 50 minimum diameter department butt of toper friction pulley, friction pulley spring 59 is in the state of relaxing.

This equipment is installed in the porcelain dish packing assembly line, and the porcelain dish passes through the conveyer belt and carries forward to objective table 20 on, because need great moment of torsion just to make it rotate when the 24 outage of conveying motor to make the porcelain dish follow the in-process of conveyer belt motion to conveyer belt 22 upside, the porcelain dish drives conveyer belt 22 and rotates, thereby makes conveyer belt shaft 23 rotate.

The front side of the conveyor belt 22 is provided with a conveyor belt which moves up and down with the conveyor belt 22 and connects the next process.

When the plates have moved to the upper side of the conveyor 22, the plates stop moving, and the stage 20 is lowered by the weight of the plates by a distance greater than the height of the plates, the first plate being lower than the conveyor.

In the descending process of the objective table 20, the motion sensor 26 moves downwards along the front end wall of the objective table sliding cavity 39, so that the motion sensor 26 is triggered, and further the conveying motor 57 is started in a delayed manner, when the objective table 20 stops, the conveying motor 57 is just started, so that the conveying motor shaft 58 is driven to rotate, and further the tapered friction wheel 50 is driven to rotate, so that the sliding friction wheel 51 is driven to rotate, so that the spline housing 52 rotates, and further the driving bevel gear shaft 55 rotates, so that the driving bevel gear 56 rotates, so that the driven bevel gear 54 is driven to rotate, and further the right conveying wheel shaft 35 rotates, so that the right conveying wheel 36 rotates, and further the foam plate abutted to the conveying wheel 36 moves to the upper side of the porcelain dish rightwards through the buffer plate conveying cavity 38.

The right guide bar 12, which is higher than the baffle transport chamber 38, prevents the foam board moving to the right from stopping on the upper side of the stage 20 due to its too high speed.

After the first foam board stops on the porcelain dish again, the conveyor motor 57 stops, and the second porcelain dish just moves and drops to the first foam board at this moment.

At this moment, under the action of the gravity of the porcelain dish, the objective table 20 descends again, and in the descending process of the objective table 20, the speed regulation pull rope 27 is pulled, so that the spline housing rotating seat 53 overcomes the elastic force of the friction wheel spring 59 to move forwards, the spline housing 52 is driven to move forwards, the sliding friction wheel 51 is further driven to move forwards to abut against the part with the larger diameter of the conical friction wheel 50, and the transmission ratio between the conical friction wheel 50 and the sliding friction wheel 51 is increased.

When objective table 20 stops again, conveying motor 57 starts to drive sliding friction wheel 51 and rotate, because the rotational speed of sliding friction wheel 51 this moment is greater than the rotational speed for the first time, thereby make conveying wheel 36 rotational speed also be greater than the rotational speed for the first time, thereby make in the same time, the foam board quantity that conveying wheel 36 outwards carried also increases, promptly in the time that next porcelain dish dropped, thereby carry out two foam boards in buffer board storage chamber 34 and drop to present porcelain dish on.

By analogy, when one layer of the porcelain plate is added, one piece of the foam plate between the porcelain plates is added.

When the object stage 20 moves downward to touch the contact switch 40, the contact switch 40 is triggered to start the transmission motor 24, so that the transmission belt wheel shaft 23 rotates to drive the transmission belt wheel 21 to rotate, so that the transmission belt 22 rotates, and the stacked ceramic plates on the upper side of the transmission belt 22 are conveyed forward to the next process.

In the process of conveying the porcelain dish forward, because the porcelain dish is gradually far away from the conveyor belt 22, the gravity given to the objective table 20 by the porcelain dish is gradually reduced, but due to the friction force of the one-way friction block 28, the objective table 20 moves upwards relative to the guide rod 12 until the friction force is larger, so that the objective table 20 slowly moves upwards in the process of conveying the porcelain dish away from the conveyor belt 22, and the porcelain dish can be smoothly conveyed to the conveyor belt from the conveyor belt 22.

When the dish is completely separated from the conveyor belt 22, the stage 20 moves upward to the initial position faster by the elastic force of the return spring 11 because the stage 20 loses the gravity action of the dish.

If the number of stacked ceramic plates in one package needs to be adjusted, the adjusting plate 41 is rotated to drive the contact switch screw rod 42 to rotate, so that the contact switch 40 moves up and down, the distance from the beginning of the movement of the objective table 20 to the contact switch 40 is changed, the distance of the descending of the objective table 20 is changed, and the number of stacked ceramic plates is adjusted.

The invention has the beneficial effects that: when the porcelain dish was placed on the objective table, make the height of a porcelain dish of objective table decline under the action of gravity of porcelain dish, thereby make follow-up porcelain dish can pile up smoothly to first porcelain dish on, the transport shaft rotates simultaneously and makes the cystosepiment of buffer board storage intracavity move right to the porcelain dish on, and every pile of one deck porcelain dish, the rotational speed increase of transport shaft is a bit, the cystosepiment of carrying out in the buffer board storage intracavity is just more one, thereby realized piling up along with the porcelain dish, cystosepiment between porcelain dish and the porcelain dish increases gradually, thereby make to pile up the porcelain dish of accomplishing and fall the back, there is sufficient buffer board between the porcelain dish of lower floor and the upper porcelain dish, thereby avoid the extrusion of upper porcelain dish to make the porcelain dish of lower floor cracked.

It will be apparent to those skilled in the art that various modifications may be made to the above embodiments without departing from the general spirit and concept of the invention. All falling within the scope of protection of the present invention. The protection scheme of the invention is subject to the appended claims.