GB2317679A

GB2317679A - Firing shelf and charging device for ceramics

Info

Publication number: GB2317679A
Application number: GB9720548A
Authority: GB
Inventors: Friedherz Becker; Ralf Binninger; Johannes Figel; Bernd Stender
Original assignee: Riedhammer GmbH; Riedhammer GmbH and Co KG
Current assignee: Riedhammer GmbH; Riedhammer GmbH and Co KG
Priority date: 1996-09-26
Filing date: 1997-09-26
Publication date: 1998-04-01
Anticipated expiration: 2017-09-26
Also published as: PT102051A; GB2317679B; ITMI972100A1; GB9720548D0; DE19639531C1; IT1294744B1; PT102051B

Abstract

A firing shelf of refractory ceramic material for receiving ceramic items(24) to be fired in a kiln, comprising a rectangular firing table to be mounted on a kiln car, with a row of spaced props(16) along each of two opposite edge regions, and with opposite pairs of props in each row being connected by a plurality of rollers arranged above each other in spaced apart relationship, to define a plurality of stock planes receiving ware(24) on kiln furniture(22). A loading and unloading device comprises longitudinally extending, laterally and vertically displaceable lifting arms, interconnected by a series of longitudinally driven two-part rollers, which carry the kiln furniture off the firing table onto an appropriately positioned charging table.

Description

2317679 1 A firing shelf with an associated loading and unloading device

The invention concerns a firing shelf (stand) of a refractory ceramic material for receiving ceramic items, and an associated loading and unloading device.

Various furnace types are known for firing ceramic items, for example tableware. Tunnel kilns and roller kilns as representatives of furnaces working continuously and hoodtype kilns or shuttle kilns as representatives of furnaces working discontiuously are of particular importance.

Particularly in firing delicate items as china, the loading and unloading of the items onto or from a corresponding base is the special problem. In a tunnel kiln, Lhe base normally is constituted by a kiln car, in a roller kiln by a plate, for example. The different bases are called firing table in the following- While in the past each single item was placed separately onto corresponding props (socalled kiln furniture) (US 3,137, 910 A, DE 28 44 281 Al, DE 35 16 490 Al), modern firing table structures have become known in recent years, which are constriicted like a shelf and enable the items to be loaded and unloaded automatically (DE 43 22 099 Cl, DE 44 05 269 Cl).

2 Associated devices fox loading and unloading these firing table structures are described in the DE 44 11 412 Cl.

These firing shelves and associated loading and unloading devices have been accepted very quickly in the market. They enable the items to be loaded and unloaded efficiently and, above all, fully automatically.

It is an object of the invention to further develop the construction of these modern firing shelves as well as the associated loading and unloading devices and to provide alternative embodiments, respectively.

The invention is based on the following knowledge:

The firing shelves according to the DE 43 22 099 Cl and DE 44 05 269 Cl are characterized essentially by supports (props) projecting vertically from the firing table and being arranged behind each other in rows along opposite edge regions of the firing table. The props of one row are connected by rails or rest elements running horizontally, onto which base plates for the items to be fired are laid, for example, (DE 43 22 099 Cl).

In the embodixaent according to the DE 44 05 269 Cl, the rails or rest elements are used at the same time for guiding rollers which extend perpendicularly to the rails extending between the supporting rows.

Accordingly, the device for the loading and unloading of the items has to be effected in the direction of the lateral rails (support rows) or the device is placed laterally upon the free ends of the rollers from outside.

The solution according to the invention presents a firing shelf, wherein the lateral rails/rest elements are eliminated. Thereby, regions being open to the top result 3 between adjacent props of a corresponding row of props so that an associated loading and unloading device can be fed between props of one row from outside and moved vertically.

The invention in its most general embodiment concerns a firing shelf of a refractory ceramic material for receiving ceramic items to be fired, having the following features: - a displaceable firing table having a square or rectangular basis - a row of props extending vertically is disposed on two opposite edge regions of the firing table, respectively, the props of each row are spaced apart, - two opposite props of the two rows, respectively, are connected by a plurality of rest elements for the items, which are arranged above each other in spaced apart relationshipAs is following further from the description of the associated loading and unloading device given below and with the embodiment, according to the invention, a rebuilding of the known firing shelves at 90 degrees iu carried out, the function of the rest elements being modified aL the same time. While the lateral rest elements (rails) of the prior art serve either to receive rest plates for the items or to perform the function of bearings for conveyor rollers, the rest elements now serve directly as conveying path for the items and, accordingly, they are disposed perpendicularly to the direction for the loading or unloading of the items.

In a first embodiment, the rest elements may consist of carriers which are connected non-positively at their ends to the two associated vertical props. In that, the firing shelf is static and the conveying means are provided only by the loading and unloading device, as will follow from the description below.

A In an alternative embodiment, the rest elements consist of rollers which are guided rotatably at the ends on the two associated vertical props. This embodiment is a "dynamic" one, because the rest elements provide a wonveying means (a roller path) at the same time. In contrast to the prior art (DE 44 05 269 Cl.), the rollers are guided directly in the props and not on additional resr elemen?--s (rai.ls).

Known bearings may be used for _rotatably guiding the rollers on or in the props. These may be metallic or ceramic bearings depending on the - L"ield of application. In order to guarantee a good turnability of the rollers, the bearings are to be selected so that an occurrina frictional resistance is as low as possible.

The described firing shelf can be loaded and unloaded in a particularly sinple manner. For that a device according to claim 3 of the DE 44 11 412 Cl mav be used. In addition, the invention proposes a loading and unloading device being particularly adapted to tIhe firing shelf described above, lowing features:

which is characterized bv the fol a suppurLing structure having two supporting arms projecting horizontally and extending transversely to the rest elements, which supporting arms are adjustable together in height and are guided in relation to each other on the supporting structure, a plurality of rollers extend from each supporting arm behind each other in spaced apart relationship in the direction towards the _resiDective other supporting arm, the rollers are guided drivably on the respective supporting arm, - the supporting arms and the rollers being guided on each supporting arm extend within a common horizontal plane, respectively, the distance between the rollers on each supporting arm is selected to be able to guide the _rollers between the region between adjacent props of a corresponding support row of the firing shelf, respectively, - the length of the rollers on each supporting arm is selected so that the total length of corresponding rollers of each supporting arm is longer than the distance between the opposite rows of props of the firing shelf, - the supportinq arms are movable towards each other along a horizontal plane until the free ends of corresponding rollers of each supporting arm are connected with positive fit.

In this way, the known load-ing and unloading device is developed as follows:

The supporting arms and the rollers disiDosed on the supporting arms are guided from outside the firing shelf to the vicinitty of the firing shelf and then in the direction towards each other so that the respective rollers of each supporting arm are guided between adjacent props of a support row until the respective corresponding ends of two rollers corinect to each other with positive fit.

In principle, it would also be possible to dispose one continuous roller on a support-ing arm and to guide it at one side between the props; however, this may result in the impossibility of an exact horizontal adjustment of the rollers being then guided and driven on one side, parLicula--ly with larger firing table widths. By dividing 6 the rollers into two portions (each of which is guided on a supporting arm), the roller lengths can be shortened to a half, as is shown in the following description of the figures.

Because the supporting arms are vertically adjustable, the rollers (roller planes) can be guided into the firing shelf at any location or displaced gradually from a plane to the plane located below or above in loading and unloading. Particularly, ---E the firing shelf is loaded or unloaded upwardly or downwardly, t-h-is can be done continuously without the need to displace the supporting arms between the individual vertical positions horizontally.

The rollers of a supporting arm, which form a sectional roller plane, mav be driven individually or commonly- A common drive ensures a maximum of svnchronism. If the rollers of both supporting arms are driven synchronously, the svnchronisi-a of the whole rolier plane is aptimized.

The connection of corresponding roller trusta at their ends may be performed in a variety of ways, for example in that the tree ends of a roller portion are formed with a tapered tip and the free ends of the corresponding roller portions are formed with a corresponding reception opening for the tip, t-he tip and the reception opening, respectively, having a conical iform, for example, which. has a centering function at the same time- Further characteristics of the invention follow from the features of the subclains and the other application documents- The invention will be explained below with an embodiment. Here, schematically 7 Fig. 1 shows a vertical section (along line A-A of Fig. 4) through a firing shelf according to the invention with an associated loading and unloading device, Fig- 2 shows a vertical section (perpendicularly to the conveying direction) of the firing shelf according to Fig. 1 with the loading and unloading device in the non-operational state, Fig- 3 shows a section according to Fig. 2 with the loading and unloading device in the operational position, Fig. 4 is a partially sectional illustration along line B-B of Fig. 1, Fig. 5 is an enlarged illustration of the roller ends of the loading and unloading device - The principle construction of the firing shelf and the associated loading and unloading device follows from Figs- 1 to 5, when viewed as a whole.

According to that, the firing shelf consists of a firing table 10 being a coruponent of a kiln car 12 with wheels 14.

The conveying direction of the oven carriage 12 is given by arrow T in Fig. 1.

The firing table 10 has a rectangular basis. Fifteen props 16 are arranged in spaced apart relationship behi.nd each other on the edge regions 10L and 1OR being opposite in the conveying direction, respectively, which are fastened with their lower ends in the firing table 10 and which project upwardly in vertical direction- As can be seen from Figs- 2 to 4 in particular, two opposite props 16 of the two support rows are connected, 8 respectively, by a Plurality of rollers 18 being arranged above each other in spaced apart relationship.

The rollers 18 are guided rotatably, but not driven, in corresponding bearings in the regions of the props 16- In this way, several (here: 6) stock planes 20 are formed for the items, each stock plane 20 consisting of a plurality of rollers 18 being disposed horizontally behind each other (along a horizontal plane).

Prom Figs- 1 to 4 follows - very schematically - the position ot the items to be fired (here: porcelain plates 24) which usually rest on kiln furniture 22, the size of which - viewed in the conveying direction T being larger than the distance between two adjacent rollers 18 of a stock plane 20.

Accordingly, the firing shelf according to the invention consists only of the firing table 10, two rows of fifteen props 16 each and a total of ninety rollers 180, each stock plane 20 being formed by fifteen rollers 18.

The associated loading and unloading device has as well an extremely simple structure. It consists of two lateral supporting arms 26L, 26R which are hinged at the ends in vertical carriers 28L and 28R_ The supporting arms 26L, 26R are displaceable vertically along the carriers 28L, 28R and the carriers 28L, 28R are movable laterally (in the direction of arrow S).

Thirty rollers 30 projecL from the inside of each supporting arm 26L, 26R in the dizection towards the corresponding supporting arm 26R, 26L, the LoLal of thirty rollers 30 being arranged in fifteen roller pairt; having a smaller distance between each other than the roller pdirs ainong each other (Fig. 4).

9 The rollers 30, at their end at the supporting arm, are running rotatably on bearings in the associated supporting arm 26R, 26L and each has a toothed wheel at this end (not shown), and a common driving chain (not shown) which is driven by a motor (also not shown) causes uniform rotation of all rollers 30 of a supporting arm. Tile drives for the supporting arms 26R, 26L are synchronized so that all rollers 30 rotate at Lhe same time and uniformly, as will be described below.

The rollers 30L being disposed an the supporting arm 26L have a conical forTn 32 at their free end, while the rollers 3OR being disposed on the supporting arm 26R have a corresponding conical recess 34- For loading and unloading the firing shelf, the kiln car 12 is displaced into the region of the loading and unloading device (Fig. 2). For that, the supporting arms 26 have been moved away from each other so far that the kiln car 12 can be guided between the rollers 30L, 30R.

For unloading the supporting arras 26L, 26R are displaced downwardly along the carriers 28L, 28R until the rollers 30L, 30R are located below the lowest stock plane 20 (Fig2).

Then, the supporting arras 26L, 26R are moved horizontally towards each other until the respective cones 32 engage with the associated conical recesses 34 and adjacent rollers 30L, 30R mesh with form-fit. Afterwards, the supporting arms 26L, 26R (and thus also the rollers 30) are moved upwardly for a little distance, in order Lo raise the kiln furniture 22 of the lowest stock plarle 20 a little (Fig. 3).

Next, the rollers 30 are put into rotational motion so that the items 24 (on the liners 22) can be guided out of the firing shelf.

Afterwards, the supporting arms 26 - as described previously - are displaced further upwardly until they take up the kiln furniture 22 of the next sLock plane 20 which then is unloaded in the same wav.

Accordingly, the loading is performed in a reversed manner (that is from the top to the bottom).

It is understood that for loading as well as unloading each conveying plane 36 has to be guided to the corresponding height to the side of the firing shelf to be able to carry away or to feed the kiln furniture 22 with the items 24.

When the firing shelf is unloaded and then reloaded, for example, the supporting arms 26 are returned horizontally to the position illustrated in Fig. 2 while uncoupling the associated rollers 30L, 30R at the sme time, the drive of which is then switched off again- I1

Claims

C 1 a i m s

A firing shelf of a refractory ceramic material for receiving ceramic items, having the following features:

1.1 a displaceable firing table (10) having a square or rectangular basis, 1-2 a row of props (16) extending vertically is disposed on two opposite edge regions (IOL, 1OR) of the firing table (10), respectively, 1.3 the props (16) of each row are spaced apart, 1.4 two opposite props (16) of the two rows, respectively, are connected by a plurality of rest elements (30) for the items, which are arranged above each other in spaced apart relationship.

The firing shelf according to claim 1, wherein the rest elements consist of carriers being connected nonpositively at their ends to the two associated vertical props- The liring shelf according to claim 1, wherein the rest elements (30) consist of rollers which are guided 12 rotatably at their ends in the two associated vertical props (16).

4. A loading and unloading device, particularly for a firing shelf according to claim 1, having the following features:

4.1 a supporting structure having two supporting arms (26L, 26R) projecting horizontally and extending transversely to the rest elements (30), which supporting arms are adjustable together in height and are guided in relation to each other on the supporting structure (28), 4.2 a plurality of rollers (30) extend from each supporting arm (26L, 26R), one behind each other in spaced apart relationship in the direction towards the respective other supporting arm (26R, 26L), 4.3 the rollers (30) are guided drivably on the re.5pective supporting arm (26L, 26R), 4-4 the supporting arms (26L, 26R) and the rollers (30) being guided on each supporting arm (26L, 26R) extend within a common horizontal plane, 4-5 the distance between the rollers (30) on each supporting arm (26L, 2GR) is selected to be able to guide the rollers (30) within the region between adjacent props (16) of a corresponding row of the firing shelf, respectively, 4.6 the length of the rollers (30) on each supporting arm (26L, 26R) is selected so that the total length of corresponding rollers (30L, 30R) of each supporting arm (26L, 26R) is longer than the 13 distance between the opposite rows of props (16) of the firing shelf, 4-7 the supporting arms (26L), (26R) are movable towards each other along a horizontal plane until the free ends (32, 34) of corresponding rollers (30L, 30R) of each supporting arin (26L, 26R) are connected with positive fit.

The loading and unloading device according to claim 4, wherein the free ends of the rollers (30L) of a supporting arm (26L) are formed with a tapered tip (32) and the free ends of the rollers (30R) of the other supporting arm (36R) are formed with a corresponding reception opening (34) for the tip (32).

The loading and unloading device according to claim 4, wherein the rollers (30L, 30R) of the two supporting arms (26L, 26R) can be driven synchronously.

lt Amendments to the claims have been filed as follows A loading and unloading device for a firing shelf having the following features:

1.1 a displaceable firing table having a square or rectangular basis, 1.2 a row of props extending vertically is disposed on two opposite edge regions of the firing table respectively, 1.3 the props of each row are spaced apart, 1.4 two opposite props of the two rows, respectively, are connected by a plurality of rest elements for the items, which are arranged above each other in spaced apart relationship, wherein the device comprises:

1.5 a supporting structure having two supporting arms projecting horizontally and extending transversely to the rest elements which supporting arms are adjustable together in height and are guided in relation to each other on the supporting structure A 1.6 a plurality of rollers extend from each supporting arm one behind each other in spaced apart relationship in the direction towards the respective other supporting arm 1, 1.7 the rollers are guided drivably on the respective supporting arm, 1.8 the supporting arms and the rollers being guided on each supporting arm extend within a common horizontal plane, 1.9 the distance between the rollers on each supporting arm is selected to be able to guide the rollers within the region between adjacent props of a corresponding row of the firing shelf, respectively,

1.10 the length of the rollers on each supporting arm is selected so that the total length of corresponding rollers of each supporting arm is longer than the distance between the opposite rows of props of the firing shelf, 1.11 the supporting arms are movable towards each other along a horizontal plane until the free ends of corresponding rollers of each supporting arm are connected with positive fit.

The loading and unloading device according to claim 1, wherein the free ends of the rollers of a supporting arm are formed with a tapered tip and the free ends of the rollers of the other supporting arm are formed with a corresponding reception opening for the tip 1 LI The loading and unloading device according to claiin 1, wherein the rollers of the two supporting arins can be driven synchronously.