EP0989378A1

EP0989378A1 - Kiln car

Info

Publication number: EP0989378A1
Application number: EP99850122A
Authority: EP
Inventors: Gjertrud Rian; Egil Syvertsen; Rune Roligheten
Original assignee: Borgestad Fabrikker AS
Current assignee: Borgestad Fabrikker AS
Priority date: 1998-08-26
Filing date: 1999-08-12
Publication date: 2000-03-29
Also published as: NO983925L; NO983925D0

Abstract

The invention relates to a kiln car comprising a car frame (1, 2, 3) having a mounting surface (6) and stacks of positioning shelves (16) arranged on the mounting surface. The invention is characterized in that each stack of positioning shelves (16) has a central support/fixation point (7, 17, 18). The central support comprises a center pedestal (7) which passes through the individual positioning shelves (16) in the stack.

Description

The invention relates to a kiln car comprising a car frame having a mounting surface and stacks of positioning shelves arranged on the mounting surface.
Such kiln cars are used for the firing of porcelain wares. The kiln car is moved through a firing furnace where the porcelain placed on the positioning shelves is fired. The kiln car may have a car frame with or without rollers. Hence the kiln car may be, for example, a flat cart for rolling transport or, for example, an actual car having wheels for conveyance through the tunnel furnace.
On the mounting surface are placed stacks of positioning shelves. Each positioning shelf has two or preferably three support points. Thus, from DE 4,304,646 C, for example, there is known a kiln car assembly having positioning shelves which are supported in a stack having three respective support points or feet. The positioning shelves are stacked atop one another with the aid of mutually engaging sleeve-mandrel units. The stacks are built up on the mounting surface of the car.
The purpose of the present invention is to provide a kiln car as introduced above, which kiln car permits greater flexibility with respect to the construction of the stack and the positioning of the ware to be fired, offering the possibility of improved utilization of space.
A particular objective of the invention is to provide the requisite conditions for automatization, i.e., automatic positioning and removal of stacks of positioning shelves, with or without porcelain ware , onto and from, respectively, the kiln car.
Therefore, according to the invention, there is proposed a kiln car comprising a car frame having a mounting surface and stacks of positioning shelves arranged on the mounting surface, which kiln car is characterized in that each stack of positioning shelves has a central support/fixation point.
The central support/fixation point for the stack provides free access to the positioning shelves from all sides. It also enables the use of different types of positioning shelves in the stacks. This provides increased flexibility and opportunity for more efficient utilization of space.
According to the invention, the central fixation point(s) may advantageously comprise a central pedestal that passes through the individual positioning shelves.
A particularly advantageous arrangement in this connection can be spacing members provided on the center pedestal, between the individual positioning shelves.
Especially advantageously, the spacing members may be sleeve members provided with end flanges.
The center pedestal per se may have any type of cross sectional form, although a circular or tubular cross section is preferred, as this provides for a center pedestal around which the individual positioning shelves may revolve for suitable orientation. The spacing members in the form of sleeve members having end flanges are advantageous because the end flanges will provide solid and stable support of the individual positioning shelves, which rest against an underlying end flange, while the overlying sleeve member rests on the upper side of the positioning shelf by an end flange.
The mounting surface may advantageously be formed, according to the invention, by a plurality of plates situated side-by-side, with or without spacing between the edges thereof.
Particularly advantageously these plates may rest on posts projecting upward from an undercarriage in the car frame.
According to the invention these posts, which preferably may have a polygonal or non-rounded cross section, can be extended up over the shelves to create the said center pedestals.
The polygonal or non-rounded cross section of the posts under the shelves is favorable for rotation-proof positioning of the posts in the foundation stones of the car.
In a convenient and preferred embodiment of the kiln car according to the invention, the base plates along the side edges of the car frame can rest on side beams supported by posts situated in the corner regions of the car.
This provides an easy and simple structural design, allowing space for the firing flames that operate laterally in the firing furnace through which the kiln car is moved.
According to the invention a particularly preferred material for the base plates (the mounting surface), the positioning shelves and center pedestals is nitride-combined silicon carbide, with a material marketed by the Applicant under the name NOV NX being especially recommended.
According to the invention, it is particularly advantageous for the center pedestal(s) to be movable and to be designed with a respective foot for support on the base plate/mounting surface.
This enables the lifting of the entire stack by means of the center pedestal, allowing a complete stack to be placed onto the mounting surface or removed from said mounting surface.
With this type of movable configuration of the center pedestal, the center pedestal advantageously may be detachably joined to the foot, for example by providing the center pedestal with a conical lower end for mortise engagement with an upwardly oriented, conical receival opening in the foot.
The invention will now be explained in more detail with reference to the drawings, wherein
Figure 1 is a horizontal plan view of a kiln car according to the invention,
Figure 2 is a vertical sectional view through the kiln car in Figure 1,
Figure 3 is a vertical sectional view through a stack of positioning shelves positioned on the kiln car,
Figure 4 is a sectional view along line IV-IV in Figure 2,
Figure 5 is a sectional view along line V-V in Figure 1.
Figure 6 is a sectional view through three movable positioning shelves according to the invention,
Figure 7 is a view of one of the positioning shelf stacks in Figure 6, with the foot detached from the center pedestal,
Figure 8 is a sectional view through a kiln car according to the invention, with stacks of various types of positioning shelves, and
Figure 9 is a horizontal plan view of the kiln car according to Figure 8.
The kiln car shown in Figures 1 and 2 is constructed with the conventional quadrate shape indicated in the plan view. A typical kiln car will have sides that are about 1.5 meters long. The car has, in practice, a height of 40-50 cm.
The car shown in Figures 1 and 2 is a car designed for movement through a tunnel furnace, on tracks in the tunnel furnace. For this purpose the car is provided with rollers, not shown. This part of the car frame is omitted, as it involves a technique well known to the person skilled in the art.
Similarly, an optional insulating skirt, which extends down from the car, is not shown.
The car in Figures 1 and 2 comprises a car frame built up from a metal base, or undercarriage, 1 (see Figure 2) and a permanent car frame member positioned on this metal base, shown here in the form of a quadrate frame 2 of insulating casting material and layers of ceramic fiber mats 3 placed in frame 2.
The undercarriage 1 may be a whole trough-shaped base frame, or it may be constructed as a suitable lattice work to support the fiber mats 3 and the foundation stones 4 shown in Figure 2. Foundation stones 4 form the bases for vertical posts 5 extending upwardly through fiber mats 3 and supporting base plates 6. The foundation stones 4 are commonly known fireproof blocks having an opening therein for receival of the associated post 5. In the embodiment example posts 5 have a regular hexagonal cross section externally and are set down into correspondingly formed recesses in foundation stones 4, see also Figure 4. The posts 5 are hollow, as indicated in Figures 2 and 4.
A total of nine posts 5 is provided in the kiln car, and each post is extended upward over the mounting surface created by base plates 6 in the form of respective hollow, cylindrical center pedestals 7. In the transitional area between the respective post 5 and the upward projecting center pedestal there is formed an annular shoulder against which a disc rests. These discs form supports for base plates 6.
In the corner regions of the car are situated corner posts 9, as shown. These are shaped as tubes and extend a short distance upward above the top side of frame 2. A locking block 10 is positioned in respective corner posts 9. These locking blocks 10 form a support for side beams 11. These side beams 11 form the edge supports for the outer base plates 6, as shown in Figures 1 and 2.
Base plates 6 in the embodiment example are arranged such that they abut with one another, as shown at 12, and are mutually separated by spacing 13, and the base plates 6 are further provided with suitable recesses adapted to fit the respective center pedestals 7, which project up between adjacent base plates 6. For stabilizing the base plates there are provided locking stones 14, see also Figure 5. Locking stones 14 are formed as simple bodies provided with a slot 15 to receive the edge portions of the adjacent plates.
Center pedestals 7 serve as support/fixation members in stacks of positioning shelves 16; see Figure 3. The individual positioning shelves 16 rest on spacing members in the form of flange sleeves 17, which are threaded onto center pedestal 7. As is apparent from Figure 3, a flange sleeve is put on first, which rests against the mounting surface, i.e., on base plates 6. A positioning shelf 16 is then threaded on (each positioning shelf is provided with a hole suitable for this insertion), and the spacing sleeves and positioning shelves then follow in alternation. Flanges 18 on sleeves 17 serve to form a support surface for positioning shelves 16 and press against the top side of the underlying shelf, providing for a consequently stable and effective support for the positioning shelves in the stack. The porcelain wares to be fired (not shown) are placed on the positioning shelves.
In the embodiment shown in Figures 1 to 5, the center pedestals are fixedly mounted on the car frame. According to the invention, there may be employed movable center pedestals that may be set directly onto base plates 6 with the aid of suitable feet. A possible embodiment of this type, according to the invention, is shown in Figures 6 and 7. Here there are shown three stacks 19, 20, 21 of positioning shelves on the mounting surface 6 of a kiln car. Each such stack has a center pedestal 22, see Figure 7, and a mounting foot 23 detachably connected to this center pedestal. Foot 23 may have any suitable form whatsoever. For example, it may be a conventional round foot, a crosspiece foot, a triangular foot, etc. In the embodiment example, foot 23 has a conical opening to receive a conically shaped lower end 25 of the center pedestal 22. On center pedestal 22 a stack of positioning shelves is built up in the same manner as in Figure 3, i.e., with alternating positioning shelves and spacing sleeves.
The movable stacking design will be advantageous in connection with automatization, inasmuch as the entire stack, i.e., the center pedestal, positioning shelves and any porcelain wares thereon can be moved as one unit to and from mounting surface 6.
Figure 8 is a sectional view through a kiln car where the intention is to use both fixed center pedestals 26, corresponding to center pedestals 7 in Figures 1 to 3, and movable center pedestals 27, corresponding to the loose center pedestals in Figures 6 and 7.
The positioning shelves may have different forms, as is indicated in the horizontal plan view in Figure 9. In Figure 9 there are shown different types of positioning shelves 28, 29, 30, to illustrate the variation possibilities. The porcelain wares that are to be fired are indicated, by way of example, with broken lines 31.
Of course, the distance between positioning shelves can be varied by the utilization of spacing sleeves of different lengths. The diameter of the center pedestals can also be varied. One and the same foot type 23 can, of course, be combined with different sizes (diameters) of center pedestals. The lengths of the center pedestals naturally may be varied according to need.
The new kiln car according to the invention has the advantage that there is only one mounting point for the positioning shelves in a stack. The central pedestal provides very good access to the positioning shelves. The system will also be more flexible in that it there are no limitations for the height differences of the positioning shelves. The positioning shelves can also be rotated, which will facilitate the access for placing the porcelain wares thereon. The thermomechanical properties of the positioning shelves are enhanced by virtue of their being locked at the center only, and thereby being freely expandable. The movable variant is especially advantageous because it provides for complete or greater freedom for placement of the stacks on the mounting surface. The invention provides for the possibility for automatization, optionally in a plurality of stages.
A recommended material for the positioning shelves, the posts, the center pedestals, the base plates and the spacing sleeves is nitride-combined silicon carbide, particularly a type supplied by the Applicant under the name NOVA Nx.

Claims

A kiln car comprising a car frame (1, 2, 3) having a mounting surface (6) and stacks of positioning shelves (16) arranged on the mounting surface,
characterized in that each stack of positioning shelves (16) has a central support/fixation point (7, 17, 18).
A kiln car according to claim 1, characterized in that the central fixation point(s) comprise(s) a center pedestal (7) passing through the individual positioning shelves (16) in the stack.
A kiln car according to claim 2, characterized by spacing members (17) on the center pedestal (7) between the individual positioning shelves (16).
A kiln car according to claim 3, characterized in that the spacing members are sleeve members (17) provided with end flanges (18).
A kiln car according to one of the preceding claims, characterized in that the mounting surface on the car frame is formed by a plurality of plates (6) situated side-by-side.
A kiln car according to claim 5, characterized in that the plates (6) rest on posts (5) projecting upward from an undercarriage (1) in the car frame.
A kiln car according to claim 6, characterized in that the posts (5) are extended upward over the plates (6) as center pedestals (7).
A kiln car according to one of the claims 5 to 7, characterized in that the plates (6) along the side edges of the kiln car rest on side beams (11) which are supported by posts (9) situated in the corner regions of the car.
A kiln car according to one of the preceding claims, characterized in that the positioning shelves (16) and the center pedestals (7) are made of nitride-combined silicon carbide.
A kiln car according to one of the preceding claims 2 to 9, characterized in that the center pedestal(s) are detachable and are designed with a foot (23) for support on the mounting surface (6).
A kiln car according to claim 10, characterized in that the center pedestal (22) has a movable foot (23).
A kiln car according to claim 11, characterized in that the center pedestal (22) has a conical lower end (25) for mortise engagement with an upwardly oriented conical receival opening (24) in the foot (23).